Does HIV kill cells?
michaelr at u.washington.edu
Sun Mar 27 12:53:21 EST 1994
In regard to cell killing by HIV, it depends on the cell type that your
talking about and the strain of HIV. Many strains, especially lab
adapted strains like HIV-1/Lai can induce syncytia in CD4+ cells which
then go on to die. However, some strains of HIV do not induce syncytia.
More recenly HIV has been shown to induce apoptosis in some cell lines,
like CEM cells, a CD4+ tumor cell line. However, again, not all strains
of HIV do this, and the strains that do induce apoptosis in CEM cells may
not do it in other cell lines. The situation in CD4+ T cells in vivo is
even less clear, and it is postulated that indirect mechanisms are
responsible for the depletion of CD4 cells in vivo. This is one of the
most important questions in AIDS pathogenesis right now. Thus, to
summarize, some strains of HIV can definitely kill directly some CD4+
cell lines, but it is not known if this direct killing is responsible for
the depletion of CD4+ cells in vivo. See Robin Weiss's article in
Science (1990) 260:1273-1279 for a well written summary of "How does HIV
cause AIDS?" which addresses not only the issue of does HIV cause AIDS
but the postulated mechanisms.
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