AEGiS-11IAC: DNA fragmentation is induced in MT4 cells following cocultivation with HIV1-infected macrophages.

11th International AIDS Conference

Vancouver, British Columbia — July 7-12, 1996

DNA fragmentation is induced in MT4 cells following cocultivation with HIV1-infected macrophages.

Int Conf AIDS 1996 Jul 7-12; 11:4 (abstract no. We.A.100)
Godard CM, Serries H, Chermann JC; INSERM Unite 322, Unite de Recherches sur les Retrovirus et Maladies Associees, Marseille, France. Fax: (33) 91 41 92 50.

OBJECTIVE: To elucidate the cellular interactions which take place between blood-derived macrophages (BDM) infected with an HIV1-macrophage tropic variant and CD4+ T cells.

METHODS: BDM cultured in the presence of GM-CSF were infected with a macrophage-tropic strain isolated from the cerebrospinal fluid of an HIV1-infected man suffering encephalopathy (HIV1-PAR). 11-13 days after infection, infected BDM were cocultured with cells from an established cell line (MT4) showing CD4+ phenotype. MT4 cells were removed from cocultures at various time and analysed for cellular viability. DNA fragmentation was monitored in parallel using 1) an ELISA test which measures the nucleosome content in the cytosolic fraction and 2) the terminal-deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling technique. Cell fusion involving BDM and MT4 cells was monitored by using autoradiographycally labeled MT4 cells.

RESULTS: MT4 cells cocultivated with productively infected BDM undergo loss of cellular viability. Contact-dependent DNA fragmentation is triggered and the highest absorbance value reflecting nucleosome enrichment was detected at 20 hr after starting cocultures. By this time, nuclear fragmentation was detected in situ by means of TUNEL. MT4 cells were found to bind to infected and to non infected BDM, however the proportion of BDM showing bound MT4 cells was consistently higher in infected monolayers. Loss of cellular viability and nuclear fragmentation were not observed in MT4 cells cocultured with the lymphotropic strain HIV-LAV1BRU. BDM did not transmit virus infection to MT4 cells.

CONCLUSIONS: Infection of BDM with a macrophage tropic HIV variant is the source of de novo cellular interactions which may cause the death of bystander MT4 cells by triggering nuclear fragmentation. The possibility that lymphocyte depletion might result from collaborative effects of more than one HIV virus strain must be considered.

Keywords: AEGIS, DNA Fragmentation, Coculture, Macrophages, Antigens, CD4, HIV-1, HIV Envelope Protein gp120, T-Lymphocytes, HIV Core Protein p24, HIV, Cell Line, HIV-1 Reverse Transcriptase, HIV Envelope Protein gp160, HIV Infections, Receptors, HIV, Infection, Human, Male, pathogenicity, genetics, ICA11

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WeA100