Lentiviral vector expressing membrane-anchored or secreted antibody

Abstract

The invention concerns a multicistronic nucleic acid, in particular an isolated multicistronic nucleic acid, comprising: A) a sequence comprising successively: A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and B) a sequence compris -ing successively: B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with B2) a sequence encoding the constant regions of the heavy chain of an immunoglobulin Ig′ in secretory form; B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the spli -cing of said intronic sequence B3) and a secretory-specific poly(A) (p AS) signal from the 3′ terminal exon of said gene; B4) a se -quence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and B5) a membrane-anchored specific poly(A) signal (p AM), after the stop codon of the M2 domain, wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins.

1 - 21 . (canceled) 
     
     
         22 . Method for inducing the physiologically-regulated expression of a membrane-anchored and/or secreted antibody of interest or of a membrane-anchored and/or secreted antigen-binding domain/effector protein chimera by a B cell ex vivo, comprising exposing the B cell to a conditional pseudotyped viral vector particle allowing physiologically-regulated expression of membrane-anchored and/or secreted antibody or chimera by B cells, wherein said conditional pseudotyped viral vector particle comprises:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
   B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
   wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively:
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein; 
 and is pseudotyped with a viral envelope glycoprotein targeting B cells or CD34 +  hematopoietic stem cells. 
 
 
     
     
         23 . Method for treating disease in a subject comprising administering a therapeutically effective amount of:
 (i) a conditional pseudotyped viral vector particle comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
 
 
 B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively:
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein;
 and is pseudotyped with a viral envelope glycoprotein targeting B cells or CD34 +  hematopoietic stem cells, 
 
   (ii) a plasmid comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively:
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein; 
   (iii) CD34 +  hematopoietic stem cells and/or B cells transduced with the conditional pseudotyped viral vector particle defined at (i), or   (iv) CD34 +  hematopoietic stem cells and/or B cells transfected with the plasmid defined at (ii), to a subject in need thereof.   
     
     
         24 . Method of vaccination of a subject comprising administering in a subject in need thereof a prophylactically effective amount of:
 (i) the conditional pseudotyped viral vector particle comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively:
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein;
 and is pseudotyped with a viral envelope glycoprotein targeting B cells or CD34 +  hematopoietic stem cells, 
 
   (ii) a plasmid comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively:
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein; 
   (iii) CD34 +  hematopoietic stem cells and/or B cells transduced with the conditional pseudotyped viral vector particle defined at (i), or   (iv) CD34 +  hematopoietic stem cells and/or B cells transfected with the plasmid comprising the multicistronic nucleic acid defined at (ii).   
     
     
         25 . Method of providing vectored immunoprophylaxis to a subject, comprising administering to said subject a therapeutically effective amount of 
 (i) the conditional pseudotyped viral vector particle comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively:
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein;
 and is pseudotyped with a viral envelope glycoprotein targeting B cells or CD34 +  hematopoietic stem cells, 
 
   (ii) a plasmid comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA;or 
   a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising: 
 A) a sequence comprising successively:
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising: 
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein; 
   (iii) CD34 +  hematopoietic stem cells and/or B cells transduced with the conditional pseudotyped viral vector particle defined at (i), or (iv) CD34 +  hematopoietic stem cells and/or B cells transfected with the plasmid defined at (ii).   
     
     
         26 . Method for treating and/or preventing an infectious disease, an inflammatory disease or a cancer in a subject, comprising administering a prophylactically or therapeutically effective amount of:
 (i) the conditional pseudotyped viral vector particle comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively: 
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein;
 and is pseudotyped with a viral envelope glycoprotein targeting B cells or CD34 +  hematopoietic stem cells, 
 
   (ii) a plasmid comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively: 
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
   a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein; 
   (iii) CD34 +  hematopoietic stem cells and/or B cells transduced with the conditional pseudotyped viral vector particle defined at (i), or   (iv) CD34 +  hematopoietic stem cells and/or B cells transfected with the plasmid defined at (ii),
 in a subject in need thereof. 
   
     
     
         27 . Method for inducing the physiologically-regulated expression of a membrane-anchored and/or secreted antibody of interest or of a membrane-anchored and/or secreted an antigen-binding domain/effector protein chimera by a B cell ex vivo, comprising by exposing the B cell to a plasmid comprising:
 a multicistronic nucleic acid comprising:
 A1) a sequence encoding the light chain variable domain of an antibody of interest, fused in the frame with 
 A2) a sequence encoding the constant region of the light chain of an immunoglobulin Ig; and 
   B) a sequence comprising successively:
 B1) a sequence encoding the heavy chain variable domain of said antibody of interest, fused in the frame with 
 B2) a sequence encoding the constant regions of a the heavy chain of an immunoglobulin Ig′ in secretory form; 
 B3) an intronic sequence of the gene of the heavy chain of said immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 domains coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
   wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
 a multicistronic nucleic acid encoding an antigen-binding domain / effector protein chimera, the antigen-binding domain and/or the effector protein being respectively formed by two subunits, said nucleic acid comprising:
 A) a sequence comprising successively:
 A1) a sequence encoding a first subunit AbD1 of an antigen-binding domain AbD, fused in the frame with 
 A2) a first subunit EfP1 of an effector protein EfP, or optionally a sequence encoding an effector protein EfP; and 
 
 B) a sequence comprising successively:
 B1) a sequence encoding a second subunit AbD2 of the antigen-binding domain AbD, AbD2 forming in combination with AbD1 an antigen-binding domain specifically interacting with an antigen of interest, said sequence B1 being fused in the frame with 
 B2) a sequence encoding a second subunit EfP2 of the effector protein EfP or a sequence encoding the effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B1), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain, 
 
 wherein the multicistronic nucleic acid enables the co-expression of the sequences A and B into separate proteins and wherein said sequences A and B are linked by a linking sequence enabling the co-expression of the sequences A and B in a single mRNA; or 
 a nucleic acid encoding an antigen-binding domain / effector protein chimera, said nucleic acid comprising:
 A) a sequence encoding an antigen-binding domain AbD specifically interacting with an antigen of interest; and 
 B) a sequence comprising successively:
 B2) a sequence encoding an effector protein EfP; 
 B3) an intronic sequence of the gene of the heavy chain of an immunoglobulin Ig′, said intronic sequence comprising an internal 5′ splice site enabling the splicing of said intronic sequence B3) and a secretory-specific poly(A) (pAS) signal from the 3′ terminal exon of said gene; 
 B4) a sequence, in frame with sequence B2), encoding the transmembrane and cytoplasmic domains M1 and M2 of the immunoglobulin Ig′ BCR, wherein said sequence B4) comprises, between the coding sequences of the M1 and M2 domains, an intronic sequence containing a splice site enabling the splicing of said intronic sequence between the M1 and M2 coding sequences; and 
 B5) a membrane-anchored specific poly(A) signal (pAM), after the stop codon of the M2 domain,
 wherein the nucleic acid enables the expression of the sequences A and B into a single protein. 
 
 
 
     
     
         28 . Method for inducing the physiologically-regulated expression of a membrane-anchored and/or secreted antibody of interest or of a membrane-anchored and/or secreted antigen-binding domain/effector protein chimera by a B cell ex vivo according to  claim 22 , wherein the antigen-binding domain is a single-chain antibody or a single domain antibody. 
     
     
         29 . Method for treating disease according to  claim 23 , wherein the antigen-binding domain is a single-chain antibody or a single domain antibody. 
     
     
         30 . Method of vaccination of a subject according to  claim 24 , wherein the antigen-binding domain is a single-chain antibody or a single domain antibody. 
     
     
         31 . Method of providing vectored immunoprophylaxis to a subject according to  claim 25 , wherein the antigen-binding domain is a single-chain antibody or a single domain antibody. 
     
     
         32 . Method for treating and/or preventing an infectious disease, an inflammatory disease or a cancer in a subject according to  claim 26 , wherein the antigen-binding domain is a single-chain antibody or a single domain antibody. 
     
     
         33 . Method for inducing the physiologically-regulated expression of a membrane-anchored and/or secreted antibody of interest or of a membrane-anchored and/or secreted antigen-binding domain/effector protein chimera by a B cell ex vivo according to  claim 27 , wherein the antigen-binding domain is a single-chain antibody or a single domain antibody.