This proposal describes the framework of a transitional grant for Alejandro B. Balazs, PhD. The grant would be activated after Dr. Balazs obtains an assistant professor position and would provide funding for the initial years of work. Dr. Balazs is currently a postdoctoral scholar in David Baltimore's laboratory at the California Institute of Technology. Dr. Balazs'research is focused on engineering the immune system via gene transfer as a novel means of creating protection against infectious disease in a process termed Vectored ImmunoProphylaxis (VIP). This proposal is focused on extending the recent demonstration of protection against HIV infection in humanized mice by monoclonal antibodies delivered by VIP. The proposal aims to extend these findings by determining the in vivo potency of several recently described broadly neutralizing antibodies that, in vitro, exhibited greater potency and breadth of neutralization than those described previously. It will study the potential for VIP to prevent infection by transmitted founder strains of HIV. It also aims to model human-to-human transmissions and determine the degree of protection against HIV infection conferred by VIP in a second humanized mouse model that exhibits greater immunological function. Finally, it will examine the contribution of escape mutations to the failure of VIP when expressing low concentrations of neutralizing antibodies. Together, this work will expand our understanding of the potential of using neutralizing antibodies delivered by gene transfer as prophylaxis against HIV, and it will explore viral escape, which might undermine the effectiveness of this and other vaccine approaches in humans.

Public Health Relevance

Despite tremendous cost, efforts to produce an effective vaccine against HIV have not been successful. It was recently demonstrated that engineering an immune response to produce specific antibodies against HIV could prevent infection in mice. This proposal looks to expand these findings to see if other antibodies will work in the same way. It also will determine whether this approach might protect against HIV infection through mucous membranes (the way it usually spreads in people). Finally, it will try to understand why this approach can fail by investigating the way in which HIV evolves resistance to the antibodies. The goal is to see how broadly applicable engineered immunity will be as a strategy to prevent HIV infection in humans in the future.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Career Transition Award (K22)
Project #
Application #
Study Section
Acquired Immunodeficiency Syndrome Research Review Committee (AIDS)
Program Officer
Li, Yen
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Massachusetts General Hospital
United States
Zip Code
Brady, Jacqueline M; Baltimore, David; Balazs, Alejandro B (2017) Antibody gene transfer with adeno-associated viral vectors as a method for HIV prevention. Immunol Rev 275:324-333
Saunders, Kevin O; Wang, Lingshu; Joyce, M Gordon et al. (2015) Broadly Neutralizing Human Immunodeficiency Virus Type 1 Antibody Gene Transfer Protects Nonhuman Primates from Mucosal Simian-Human Immunodeficiency Virus Infection. J Virol 89:8334-45
Deal, Cailin E; Balazs, Alejandro B (2015) Engineering humoral immunity as prophylaxis or therapy. Curr Opin Immunol 35:113-22
Deal, Cailin E; Balazs, Alejandro B (2015) Vectored antibody gene delivery for the prevention or treatment of HIV infection. Curr Opin HIV AIDS 10:190-7
Balazs, Alejandro B; Ouyang, Yong; Hong, Christin M et al. (2014) Vectored immunoprophylaxis protects humanized mice from mucosal HIV transmission. Nat Med 20:296-300
de Jong, Ype P; Dorner, Marcus; Mommersteeg, Michiel C et al. (2014) Broadly neutralizing antibodies abrogate established hepatitis C virus infection. Sci Transl Med 6:254ra129
Deal, Cailin; Balazs, Alejandro B; Espinosa, Diego A et al. (2014) Vectored antibody gene delivery protects against Plasmodium falciparum sporozoite challenge in mice. Proc Natl Acad Sci U S A 111:12528-32
Balazs, Alejandro B; Bloom, Jesse D; Hong, Christin M et al. (2013) Broad protection against influenza infection by vectored immunoprophylaxis in mice. Nat Biotechnol 31:647-52
Balazs, Alejandro B; West Jr, Anthony P (2013) Antibody gene transfer for HIV immunoprophylaxis. Nat Immunol 14:1-5