No difference in in vitro susceptibility to HIV type 1 between high-risk HIV-negative ethiopian commercial sex workers and low-risk control subjects

Host factors such as increased beta -chemokine production, HIV-1 coreceptor expression level, and HIV-1 coreceptor polymorphism have been thought to i nfluence susceptibility to HIV-1 infection. To determine the protective rol e of these factors in Ethiopians who remained HIV-1 uninfected, despite mul tiple high-risk sexual exposures, we studied 21 Ethiopian women who had bee n employed as commercial sex workers (CSWs) for five or more years, The HIV -1-resistant CSWs were compared with low-risk age-matched female controls w ho had a comparable CD4(+) cell percentage and mean fluorescence intensity (MFI). Genetic polymorphism in the CCR5, CCR2b, or SDF-1 genes appeared not to be associated with resistance in the Ethiopian CSWs, Expression levels of CCR5 and CXCR4 on naive, memory, and total CD4(+) T cells tended to be h igher in the resistant CSWs, while the production of beta -chemokines RANTE S, MIP-1 alpha, and MIP-1 beta by phytohemagglutinin (PHA)-stimulated perip heral blood mononuclear cells (PBMCs) was lower compared with low-risk HIV- 1 negative controls. In vitro susceptibility of PHA-stimulated PBMCs to pri mary, CCR5-restricted, Ethiopian HIV-1 isolates was comparable between resi stant CSWs and low-risk controls. in vitro susceptibility was positively co rrelated to CD4(+) cell mean fluorescence intensity and negatively correlat ed to CCR5 expression levels, suggesting that infection of PBMCs was primar ily dependent on expression levels of CD4 and that CCR5 expression, above a certain threshold, did not further increase susceptibility, Our results sh ow that coreceptor polymorphism, coreceptor expression levels, beta -chemok ine production, and cellular resistance to in vitro HIV-1 infection are not associated with protection in high-risk HIV-1-negative Ethiopian CSWs.