Peripheral γδ T‐cell population in HIV‐infected individuals with mycobacterial infection

Abstract

Previous studies have suggested that γδ T cells can be increased in HIV‐l;1‐seropositive individuals, although characterization of γδ T cell subtypes and correlation with clinical status of these patients have not been performed. We investigated groups of adult HIV‐seropositive persons to determine the prevalence of elevated levels of γδ T cells and whether any γδ T cell subtypes were preferentially expressed. Since a large proportion of human γδ T cells appear to be reactive to proteins encoded by mycobacteria, we also examined our patients for the incidence of mycobacterial infection. Our results show that a significant number of HIV‐positive patients have an elevated number of γδ T cells in their peripheral blood as compared to normal controls. HIV‐seropositive patients with clinical or laboratory evidence of mycobacterial infection had statistically significant increases in the percentage and total numbers of γδ T cells over the HIV‐positive persons without mycobacterial infection. An examination of the subtypes of γδ T cells revealed that certain subtypes such as Vγδ9+ and Vδ2+ T cells were preferentially elevated in the mycobacteria‐positive patients. These results suggest that an increased number of γδ T cells in HIV‐positive patients is most often seen in the setting of an opportunistic mycobacterial infection and that specific γδ T cell subtypes are stimulated under these conditions. The role of these increased numbers of γδ T cells in HIV‐associated disease is unclear but is likely a component of the response and degree of host resistance to this organism. © 1995 Wiley‐Liss, Inc. Copyright © 1995 Wiley‐Liss, Inc.