Comparative loss and maturation of peripheral blood dendritic cell subpopulations in African and non-African HIV-1-infected patients
To quantify the percentage of the two major subpopulations of blood dendritic cells (DC) in HIV-1-seropositive Ugandan individuals infected with non-clade B viruses and compare this with that seen in clade B HIV-1 infected non-African individuals. DC maturation/activation status was also investigated via the expression of CD86.
The percentage of blood DC was quantified by using flow cytometry. DC were identified as the lineage (CD3, CD14, CD16, CD19, CD20, CD56)-negative, HLA-DR-positive population and the two major subpopulations were differentiated by CD11c expression.
The percentage of blood DC was reduced significantly in HIV-1-seropositive African individuals when compared with controls (0.21 and 0.39% respectively). A similar reduction was also seen in non-African patients residing in the UK (0.19% compared with 0.36% for controls). However, there was no selective loss in either CD11c-positive or CD11c-negative subpopulations. The percentage of blood DC expressing CD86 was significantly greater in HIV-1-seropositive individuals when compared with controls and the increased expression was largely confined to CD11c-negative DC.
Africans infected with non-clade B HIV-1 showed similar reductions in the percentage of blood DC to non-Africans infected with clade B viruses. There was no selective loss of either DC subpopulation, suggesting that the ability of DC to acquire and present antigens or to produce interferon-alpha may both be impaired in HIV-1 infection.