Master of Science
Microbiology and Immunology
Recently, researchers have identified a number of anti-HIV broadly neutralizing antibodies (bNAbs), such as VRC01 and N6, capable of targeting a broad range of HIV-1 strains. Passive immunization using these patient-derived bNAbs could provide temporary protection but are limited by the short antibody half-life. While current gene transfer technology allows sustained bNAb expression, it lacks the ability to control bNAb production in vivo resulting in possible autoimmunity. To address this issue of achieving controlled bNAb expression in vivo, we hypothesize that bNAb expression from transduced Flu-specific B cells can be activated and modulated by subsequent Flu immunizations in the Flu-preimmunized animal. In this preliminary study, we have constructed a bNAb (N6 and VRC01) -expressing murine retroviral vector (MIGR) and successfully transduced Flu-specific primary B cells. Following transfusion of these cells into Flu-immunized recipient mice, we observed an anamnestic N6 antibody response with subsequent Flu immunizations.
Summary for Lay Audience
After more than 33 years of effort there is still no effective HIV vaccine to prevent transmission, and passive immunization cannot provide persistent protective antibody. Thus, gene transfer, especially utilizing retroviral vector technology, has become a very hot topic in the field due to its ability to confer continuous protective antibody production. However, continuously expressed broadly protective antibodies have autoimmune potential. Therefore, a more controlled method of antibody expression is necessary. In this study, we utilized a Flu preimmunization strategy to modify a specific type of immune cell, i.e. B cell, to provide an ideal means to modulate expression of broadly protective anti-HIV antibodies; effectively combating HIV infection while avoiding possible side effects. Specifically, Flu-specific B cells were isolated from immunized mice and an anti-HIV antibody gene, VRC01 or N6, were incorporated using a retroviral vector. These B cells were then transfused back into the Flu immunized mice followed by boosts with Flu vaccine. We observed that N6 expression increased after subsequent Flu immunizations, providing a proof-of-concept for our strategy.
Patel, Darshit, "Endogenous, controlled expression of anti-HIV-1 broadly neutralizing antibody" (2019). Electronic Thesis and Dissertation Repository. 6519.