Conformationally Specific Viral Immunogens

Abstract

The present invention provides methods of making engineered viral proteins and protein complexes that are useful as vaccine immunogens, engineered viral proteins and protein complexes made using such methods, and pharmaceutical compositions comprising such engineered viral proteins and protein complexes. Such engineered viral proteins and protein complexes may comprise one or more cross-links that stabilize the conformation of an antibody epitope, such as a quaternary neutralizing antibody, and may exhibit an enhanced ability to elicit a protective immune response when administered to a subject as a component of a vaccine.

1 . (canceled) 
     
     
         2 . A method for producing a vaccine immunogen candidate, the method comprising: (a) producing a recombinant viral envelope protein or viral envelope protein complex in a conformation that can bind to an antibody and can activate a B cell receptor, (b) performing biochemical or structural analysis to identify and select one or more regions in the recombinant viral envelope protein or viral envelope protein complex where the introduction of one or more dityrosine cross-links could stabilize the conformation, (c) introducing into the recombinant viral envelope protein or viral envelope protein complex one or more dityrosine cross-links at one or more of the regions selected in step (b) to form an engineered viral envelope protein or viral envelope protein complex, and (d) performing an assay to determine if the engineered viral envelope protein or viral envelope protein complex has one or more properties selected from the group consisting of:
 i. enhanced ability to bind to a neutralizing antibody as compared to the viral envelope protein or viral envelope protein complex,   ii. enhanced ability to bind to a broadly neutralizing antibody as compared to the viral envelope protein or viral envelope protein complex,   iii. enhanced ability to bind to and activate B cell receptors as compared to the viral envelope protein or viral envelope protein complex,   iv. enhanced ability to elicit an antibody response in an animal as compared to the viral envelope protein or viral envelope protein complex,   v. enhanced ability to elicit a protective antibody response in an animal as compared to the viral envelope protein or viral envelope protein complex,   vi. enhanced ability to elicit production of neutralizing antibodies in an animal as compared to the viral envelope protein or viral envelope protein complex,   vii. enhanced ability to elicit production of broadly neutralizing antibodies in an animal as compared to the viral envelope protein or viral envelope protein complex,   viii. enhanced ability to elicit a protective immune response in an animal as compared to the viral envelope protein or viral envelope protein complex, and   ix. enhanced ability to bind to and elicit production of antibodies that recognize quaternary neutralizing epitopes in an animal as compared to the viral envelope protein or viral envelope protein complex,   
       wherein if the engineered viral envelope protein or viral envelope protein complex has one or more properties i. to ix., the engineered viral envelope protein or viral envelope protein complex is a vaccine immunogen candidate. 
     
     
         3 . The method of  claim 2 , wherein step (d) comprises performing one or more assays to assess the ability of the engineered viral envelope protein or viral envelope protein complex to bind to a neutralizing antibody, bind to a broadly neutralizing antibody, bind to and activate a B cell receptor, elicit an antibody response in an animal, elicit a protective antibody response in an animal, elicit production of neutralizing antibodies in an animal, elicit production of broadly neutralizing antibodies in an animal, elicit a protective immune response in an animal, and/or elicit production of antibodies that recognize quaternary neutralizing epitopes in an animal. 
     
     
         4 . The method of  claim 2 , wherein at least one tyrosine of the one or more dityrosine cross-links introduced in step (c) originates from a point mutation to tyrosine. 
     
     
         5 . The method of  claim 2 , further comprising, prior to step (c), introducing into the viral envelope protein or viral envelope protein complex one or more point mutations to tyrosine at one or more of the regions selected in step (b). 
     
     
         6 . The method of  claim 2 , wherein the animal is a mammal. 
     
     
         7 . The method of  claim 2 , wherein the animal is a human. 
     
     
         8 . The method of  claim 2 , wherein the viral envelope protein or viral envelope protein complex is derived from a virus from the group consisting of Herpesvirales, Ligamenvirales, Mononegavirales, Nidovirales, Lentiviruses, Human Immunodeficiency Viruses, Retroviruses, Orthomyxoviruses, Paramyxovirus, Influenza viruses, Poxviruses, Flaviviruses, Togaviruses, Coronaviruses, Rhabdoviruses, Bunyaviruses, Filoviruses,-Hepadnaviruses, and Hepatitis viruses. 
     
     
         9 . The method of  claim 2 , wherein the engineered viral envelope protein or viral envelope protein complex is soluble.