Document 0273
 DOCN  M9590273
 TI    Unexpectedly low levels of HIV specific CTL responses in peripheral
       blood of healthy asymptomatic HIV positive individuals.
 DT    9509
 AU    Marshall PD; Ffrench RA; Benson EM; Stewart GJ; Dept. of Immunology,
       Westmead Hospital, N.S.W.
 SO    Annu Conf Australas Soc HIV Med. 1994 Nov 3-6;6:249 (unnumbered poster).
       Unique Identifier : AIDSLINE ASHM6/95291826
 AB    A loss of HIV specific CTL activity has been reported to precede an
       accelerated rate of decline in CD4 count and as such, measuring CTL
       response could be used as an indicator of impending onset of end stage
       disease. However, contrary to previously published data we have found a
       lower HIV specific response and a lower incidence of response from
       circulating peripheral blood mononuclear cells in healthy asymptomatic
       HIV+ve individuals with CD4 counts above 500/ml. Using AIDS Clinical
       Trials Group (ACTG) protocol for a standardised 51Cr release CTL assay,
       we studied 25 HIV positive individuals with CD4 counts ranging from 500
       to 1000, and 10 HIV negative controls. The CTL responses were assessed
       using autologous B cell lines, infected with recombinant vaccinia
       viruses expressing HIV-env (MN or IIIB), HIV-gag and vac-lac as control.
       The MHC-unrestricted cytotoxicity was assessed using K562 cells as
       targets. We found that only 3 of the 25 individuals had significant HIV
       specific responses and that the level of specific cytotoxicity was
       between 5-15%. This contradicts current dogma on the level of CTL
       responses in asymptomatic individuals. We suggest that to examine the
       level of HIV-specific CTL responses during the course of HIV infection,
       specific precursor CTLs should be expanded in vitro. This has particular
       significance for monitoring CTL responses during the asymptomatic phase
       and in following any possible change in response to immune based
       therapy.
 DE    Cell Line  Cytotoxicity, Immunologic/IMMUNOLOGY  CD4 Lymphocyte Count
       Human  HIV Seronegativity  HIV Seropositivity/*IMMUNOLOGY
       T-Lymphocytes, Cytotoxic/*IMMUNOLOGY  MEETING ABSTRACT

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