Increased CCR5 expression with decreased beta chemokine secretion in Ethiopians: Relevance to AIDS in Africa

Objective: This study was undertaken to determine the con tribution of HIV co-receptors and beta chemokine secretion to the increased susceptibility f or human immunodeficiency virus (HIV) infection of peripheral blood mononuc lear cells (PBMC) obtained from HIV-seronegative Ethiopian immigrants in Is rael (ETH). Study Design: Immune activation markers and HN co-receptor expression on ly mphocytes and monocytes, and beta chemokine secretion by CD8+ cells, were c ompared between ETH and non-Ethiopian Israeli (IS) HIV-negative individuals . Results: The percentage of lymphocytes and monocytes expressing CCR5 was 1. 6 and 3.0 times higher in ETH (n = 83) than in IS (n = 45), respectively (P <.001), whereas RANTES and MIP-la secretion was 0.5 and 0.7 times lower (P <.01 and P <.05). The percentage of CCR5-expressing cells and RANTES secre tion were inversely correlated (r = -0.7; P <.002). No differences were fou nd in the proportion of CXCR4-expressing cells. No correlation between CCR5 expression and cell activation profile in the whole ETH population was fou nd. However, in highly activated individuals (HLA-DR/CDS >7%), a significan t decrease in CCR5 expression was observed. Conclusions: An increased proportion of CCR5-expressing cells with decrease d beta chemokine secretion observed in ETH may account for the increased su sceptibility to HN infection of cells obtained from this group. These findi ngs may partly explain the higher susceptibility for HN infection in Africa and thus the rapid spread of acquired immunodeficiency syndrome (AIDS) in that continent.