AEGiS-07IAC: FcRII also mediates HIV entry into CD4 negative macrophages.

7th International AIDS Conference


Florence, Italy — June 16-21, 1991

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FcRII also mediates HIV entry into CD4 negative macrophages.

Int Conf AIDS 1991 Jun 16-21; 7:92 (abstract no. M.A.1002)
Nagy K, Dobronyi I, Timar I; Institute of Isotopes, Hungarian Academy of Sciences and Department of Pathology, Semmelweis Medical University, Budapest, Hungary

OBJECTIVE: To evaluate the role of FcRII(CD32) of CD4 negative human machrophage cells in receptor mediated enhancement of HIV infection.

METHODS: Membrane markers characterisation of the machrophes cell line DD were done by immunofluorescence (IF), DD cells infected with HIV directly or complexed with HIV-specific antibodies. Viral replication were monitored by IF, reverse transcriptase (RT) assay and electron microscopy (EM).

RESULTS: DD cells express CD14 antigens and FcRII (CD32) receptors onto the cell membrane. Cells are negative for FcRI, Leu M3, HLA-DR and also for CD4, even after receptor induction by vitamin D3. Dot blot hybridisation for CD4 mRNA was also negative. DD cells were not permissive for direct infection with HIV-1 (BCO41) and HTLV-3B. Treatment of cells by immunocomplexes resulted in moderate CPE but IF and RT assay were negative. EM, however, revealed HIV particles in cytoplasmic vacuoles of DD cells treated with highly diluted ( 24.000) viral: immunocomplex.

CONCLUSIONS: HIV had been endocytosed in form of immunocomplex mediated by the FcRII receptors of CD4 negative DD cells. Because of the low rate viral replication, particles accumulated in cytoplasmic vacuoles and have not been expressed into culture medium. Observation suggests that similarly to FcRI, FcRII receptor mediated enhancement represents an alternative infectious pathway independent of CD4.

Keywords: AEGIS, Antigens, CD4, HIV, Macrophages, HIV-1, Virus Replication, HIV Antibodies, HIV Infections, RNA-Directed DNA Polymerase, Receptors, HIV, HIV Core Protein p24, Receptors, IgG, Deltaretrovirus, Endocytosis, Human, virology, ICA7KWDaegis,antigens,cd4,hiv,macrophages,hiv-1,virusreplication,hivantibodies,hivinfections,rna-directeddnapolymerase,receptors,hiv,hivcoreproteinp24,receptors,igg,deltaretrovirus,endocytosis,human,virology,ica7
910616
MA1002

Copyright © 1991 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.