Normal T-cell telomerase activity and upregulation in human immunodeficiency virus-1 infection

In human immunodeficiency virus (HIV)-1 infection, decrease of telomere len gth is mainly found in CD8(+) T cells and not in CD4(+) T cells. Telomerase , a ribonucleoprotein enzyme that can synthesize telomeric sequence onto ch romosomal ends, can compensate for telomere loss. Here, we investigated if telomerase activity could explain differential telomere loss of CD4(+) and CD8(+) T cells in HIV-2 infection. Telomerase activity was higher in CD8(+) than in CD4(+) T cells from HIV-infected patients, but still in the same r ange as in healthy controls, and upregulation after stimulation was compara ble to normal. Telomerase activity in lymph node CD4(+) and CD8(+) T cells from HIV-infected patients was in the same range as that in CD4(+) and CD8( +) T cells from peripheral blood (PB) and was normal in unseparated bone ma rrow cells. Thus, our study did not provide evidence for compartmentalized elongation of telomeres in HIV infection, in patients treated with reverse transcriptase inhibitors, telomerase activity was inhibited, but this did n ot lead to accelerated toss of telomere length in vivo. Thus, differential telomere loss in CD4(+) and CD8(+) T cells in HIV-1 infection cannot be exp lained by telomerase activity. (C) 1999 by The American Society of Hematolo gy.