Abstract:
Background
The role of NK cells in slowing disease progression in
HIV-2 infected individuals compare to HIV-1 infected
individuals.
Methods
In this study peripheral blood mononuclear cells were
obtained from 30 HIV-1 and 30 HIV-2 infected subjects
from each of 3 categories of CD4 T-cell counts (>500,
200-500 and <200 cells/ul) together with 50 HIV uninfected control subjects. Lytic activity and IFN-g secretion
by NK cells from HIV-1 and HIV-2 infected subjects
were measured by chromium-release and ELISPOT
assays respectively following incubation of PBMC with
the NK-sensitive K562 cells. Viral load was also measured
from the plasma samples of the subjects.
Results
The cytotoxic response by NK cells was significantly
higher in HIV-2 than in HIV-1 infection in subjects with
CD4-T cell count >500 cell/ul (p < 0.05) and was similar
to that of the healthy controls. There was a significant
correlation between the magnitude of the NK population
and cytolytic activity in HIV-2 individuals (r = 0.27,
p = 0.01). There was also an inverse relationship between
the cytolytic activity and plasma viral load in HIV-2
infected subjects (r = -0.27, p = 0.009). Interferon-g
secretion by NK cells in ELISPOT assays was similar in
HIV-1 and HIV-2 infections at all categories of CD4+T
cell counts.
