| Description |
During an immune response against a specific antigen, often during viral infections, T cells not specific to the antigen can be activated, a phenomenon known as bystander response. The "bystander response" has been studied extensively in T cells, but when examined for macrophages through the lens of HIV, it has a different outcome and is referred to as the "bystander effect". The bystander effect is seen when macrophages are exposed to a primary infection with HIV and results in increased protection of these macrophages to a secondary infection with HIV. Based on earlier experiments in the Planelles Lab, we hypothesized that the viral envelope is responsible for the bystander effect. We tested this hypothesis by generating HIV viruses pseudotyped with unique envelopes and subjecting human macrophages with primary and secondary HIV infections to induce the bystander effect. The number of cells infected by the secondary infection were measured using fluorescent markers to determine the level of protection offered by each unique envelope. Our experiments showed a bystander effect protection level of 99% or greater with the envelopes supporting our hypothesis. The exact cause of the bystander effect is now being investigated to shed more light on this phenomenon. |
