HIV infection of CD45RA+ and CD45RO+ CD4+ T cells.
HIV preferentially infects the RO+ memory subset of CD4+ lymphocytes, and these cells are lost earlier in HIV infection than their RA+ counterparts. Although both populations express similar amounts of CD4 and bind the HIV envelope glycoprotein (gp120) equally well, calcium signals and CD4 down-regulation subsequent to gp120 binding are not the same in both populations. Data suggest these disparities are mediated by differential tyrosine kinase (TK) regulation. Syncytium formation is enhanced in RO+ cells, partly a consequence of increased leucocyte function antigen-1 (LFA-1) expression and, again, partly due to altered TK regulation. After in vitro HIV infection, reverse transcription is not detected in RA+ cells, is minimal in the RO+ class II- population, but progresses well in RO+ class II+. Infection followed by mitogen stimulation permits reverse transcription in all cells. HIV infection of RO+ cells is enhanced moderately at multiple points in the virus life cycle.
Helbert
M R
MR
Imperial Cancer Research Fund Tumour Immunology Unit, University College Medical School, London, UK.
Walter
J
J
L'Age
J
J
Beverley
P C
PC
D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology* / Q000821:virology*; D002118:Calcium / Q000378:metabolism; D004279:DNA, Viral / Q000032:analysis; D006678:HIV / Q000235:genetics; D015699:HIV Envelope Protein gp120 / Q000378:metabolism; D015658:HIV Infections / Q000473:pathology*; D006801:Humans; D017493:Leukocyte Common Antigens / Q000032:analysis*; D011485:Protein Binding; D014158:Transcription, Genetic
D004279:DNA, Viral; D015699:HIV Envelope Protein gp120; D017493:Leukocyte Common Antigens; D002118:Calcium