HIV infection of H9 lymphoblastoid cells chronically activates the inositol polyphosphate pathway.
Infection with HIV causes a reduction in the numbers and function of CD4+ lymphocytes and functional abnormalities of other cells. We have studied the effect of HIV infection on signal transduction in the H9 lymphoblastoid CD4+ cell line. Resting HIV-infected H9 cells show evidence of chronic activation with raised levels of InsP3 and InsP4, the active metabolites of the inositol polyphosphate pathway, and a consequently raised intracellular free calcium concentration. Stimulation of HIV-infected H9 cells with phytohemagglutinin (PHA) leads to a fall in the previously raised levels of InsP3 but a further rise in InsP4, whilst an attenuated intracellular calcium rise is seen with both PHA and anti-CD3 antibody. The observed effects of HIV infection on signal transduction provide a mechanism to explain the functional defects in CD4+ lymphocytes and, possibly, other cell types.
Nye
K E
KE
Department of Immunology, St Mary's Hospital Medical School, London, UK.
Pinching
A J
AJ
D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000382:microbiology*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D006868:Hydrolysis; D007295:Inositol Phosphates / Q000378:metabolism*; D010835:Phytohemagglutinins / Q000494:pharmacology; D015398:Signal Transduction
D007295:Inositol Phosphates; D010835:Phytohemagglutinins; D002118:Calcium