PD-1 Inhibitors, a Curish Therapy Ready for Clinical Trials

PD-1 (Programmed Death-1--very Star Wars) is a T-cell receptor. Technically, it is a signaling receptor that appears not only on T-cells, but on other immune system cells: B cells, natural killer T cells and macrophages.

For this discussion, though, let's focus just on T-cells. PD-1 signals to T-cells not to activate. T-cell activation is when a t-cell recognizes that cells coming at it are from a particular disease and the T-cells then present a custom package of disease-fighting strategies just for that disease. PD-1 signals to T-cells not to do this.

PD-1 seems to be a way to target latent, HIV-infected T-cells so that they can be killed. Dr. Sandrina Da Fonseca from the  Vaccine and Gene Therapy Institute, in Florida, presented test tube data at the International AIDS Society HIV Reservoirs Conference (remember, when you hear the term "HIV reservoirs," it usually means AIDS cure research). The data showed that T cells taken from people with AIDS that had a lot of PD-1 also had a lot of HIV-1 DNA in them and that contributed to bigger viral reservoirs. 

So: Lots of PD-1 in cells = lots of AIDS genetic material = a bigger viral reservoir.