HLA class II glycoprotein expression by monocytes from HIV-infected individuals: Differences in response to interferon-gamma

The expression of HLA class II glycoproteins by monocytes from HIV-infected individuals was evaluated. We found no differences in HLA-DR, HLA-DQ, or HLA-DP expression by freshly isolated monocytes from patients with clinical AIDS, HIV-infected patients without AIDS or from uninfected individuals. However, monocytes from HIV-infected individuals without AIDS responded better to stimulation with recombinant human interferon-gamma (IFN-γ) than did monocytes from patients with clinical AIDS or from uninfected individuals. The response to IFN-γ stimulation by monocytes from patients with clincal AIDS was different. Thus, the largest increases in the percentage of cells expressing HLA-DR was associated with the smallest changes in the fluorescence intensity of the population that is observed following stimulation of monocytes from other patient populations.