Target cell populations of human immunodeficiency virus type 1 in peripheral blood lymphocytes with different chemokine receptors at various stages of disease progression

We studied the distribution of human immunodeficiency virus type 1 (HIV-1) DNA in CCR5-positive and -negative peripheral blood lymphocyte populations in HIV-l-infected individuals. While HIV-1 DNA in the CCR5-positive populat ion showed no correlation with CD4 count, the increase of total HIV-1 DNA w ith lower CD4 count was mainly contributed by the increase of HIV-1 DNA in the CCR5-negative population. This might indicate the change in coreceptor usage from CCR5 to CXCR4 in later stages of disease progression, However, s ome of the samples with a high viral DNA load in the CCR5-negative populati on did not have any characteristic of the V3 loop sequence that is compatib le with CXCR4 usage or the syncytium inducing (SI) phenotype. We also did n ot find any known characteristic change predictive of the SI phenotype in V 1 and V2 sequences. Our findings showed that there might be a shift in targ et cell populations during disease progression, and this shift was not nece ssarily associated with the genetic changes characteristic of CXCR4 usage.