UC San Diego

The transactivator of transcription (Tat) is a HIV regulatory protein which promotes viral replication and chemotaxis. HIV-1 shows extensive genetic diversity, HIV-1 subtype C being the most dominant subtype in the world. Our hypothesis is the frequency of CSF CD3⁺CD56⁺ and CD3^-CD56^dim is reduced in HIV-1C compared to HIV-1B due to the Tat C30S31 substitution in HIV-1C. 34 CSF and paired blood samples (PWH, n = 20; PWoH, n = 14) were studied. In PWH, the percentage of CD3⁺CD56⁺ was higher in CSF than in blood (p < 0.001), comparable in both compartments in PWoH (p = 0.20). The proportion of CD3^-CD56^dim in CSF in PWH was higher than PWoH (p = 0.008). There was no subtype differences. These results showed CNS compartmentalization of NKT cell response in PWH.