Document 0633
 DOCN  M94A0633
 TI    Impaired phagocytosis and killing of Toxoplasma gondii by HIV-infected
       macrophages.
 DT    9412
 AU    Hewish M; Biggs BA; Kent S; Crowe SM; Walter and Eliza Hall Institute of
       Medical Research.
 SO    Annu Conf Australas Soc HIV Med. 1993 Oct 28-30;5:67 (abstract no.
       TB11). Unique Identifier : AIDSLINE ASHM5/94349022
 AB    The protozoan parasite, Toxoplasma gondii, causes asymptomatic but
       persistent infection in 30-45% of the Australian population, and
       reactivation of latent infection is a major cause of morbidity and
       mortality in AIDS patients. Impaired macrophage function during
       HIV-infection may play a role in allowing reactivation. We have studied
       the interaction between human monocyte-derived macrophages infected in
       vitro with HIV-1, and T. gondii. Phagocytosis of heat-killed
       FITC-conjugated T. gondii tachyzoites by macrophages was assessed by
       flow cytometry at 4-5 and 9-11 days after HIV-infection. In experiments
       using macrophages from three different donors, HIV-infection reduced the
       ability of macrophages to ingest parasites. Intracellular replication of
       T. gondii within macrophages was assessed by incorporation of
       3[H]-uracil. HIV-infected macrophages were more permissive to
       multiplication of the parasite than uninfected macrophages, and
       preliminary work suggests that this defect in intracellular killing can
       be reversed by interferon-gamma.
 DE    Animal  AIDS-Related Opportunistic Infections/IMMUNOLOGY  Cytotoxicity,
       Immunologic/*IMMUNOLOGY  Host-Parasite Relations/IMMUNOLOGY  Human  HIV
       Infections/*IMMUNOLOGY  HIV-1/*IMMUNOLOGY/PATHOGENICITY  Interferon Type
       II/PHYSIOLOGY  Macrophages/*IMMUNOLOGY/MICROBIOLOGY
       Phagocytosis/*IMMUNOLOGY  Toxoplasma/*IMMUNOLOGY
       Toxoplasmosis/IMMUNOLOGY  MEETING ABSTRACT

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