AEGiS-06IAC: Antibody-dependent, complement-mediated enhancement of HIV infection (C'-ADE) in a human, EBV-transformed B-cell line.

6th International AIDS Conference

San Francisco, California, USA — June 20-23, 1990

Antibody-dependent, complement-mediated enhancement of HIV infection (C'-ADE) in a human, EBV-transformed B-cell line.

Int Conf AIDS 1990 Jun 20-23; 6:334 (abstract no. 1081)
Gras G, Dormont D; Commissariata l'Energie Atomique and Centre de Recherches du Service de Sante Arm/aees, Fontenay aux Roses, France

OBJECTIVE: To define if B-cells expressing complement receptors may be targets for HIV infection mediated by antibody-dependent, complement-mediated enhancement of HIV infection (C'ADE).

METHODS: Cells: An EBV-transformed B-cell line, established from cord blood (kindly provided by D. Lefrancois, Institut Curie, Paris, France), was tested for its succeptibility to HIV in C'-ADE or standard conditions. Using immunofluorescence assay and cytofluorimetry analysis, no CD4 antigen was detected, and 30 per cent of the cells expressed complement receptor type 2. Infection: LAV1 strain of HIV1 (200 TCID50) was incubated 30 mn at +04 degrees C with HIV1 positive or negative serum (1/20) and normal serum (1/15), heat-inactivated or not, as a source of complement. This defines 4 different treatments of the virus. Cells (10 million) were then added and infection occurred for 30 mn at 37 degrees C. Cells were then washed thrice and cultivated (0.5 million cells per ml). Virus Titration: P24 antigen amounts in cultures' supernatants were measured every day. Immunofluorescence assay was performed on day 2 post-infection (P.I.). On day 2 and 5 post infection, the B-cells were thoroughly washed twice and co-cultivated in triplicate with MT2 cells, in separated compartments (Costar, Transwell system).

RESULTS: P24 appeared detectable 2 days P.I. under C'-ADE conditions (positive serum plus complement), and 5 days or more P.I. under other conditions. Two days P.I., 30 per cent of the cells expressed viral antigens when infected under C'-ADE conditions, the ratios were less than 1/10 in the other cultures (immunofluorescence). In the two co-cultivation assays, numerous (greater than 50) syncytia were observed in 3/3 wells under C'-ADE conditions, 7 and 4 days post co-cultivation. Under other conditions, 1/3 or 0/3 well was slightly positive the same day (less than 5 syncytia per well). Results are reproductible.

CONCLUSION: Transformed B-cells are targets for C'-ADE of HIV infection. Blocking experiments using monoclonal antibodies against CD4 and Complement Receptors are in progress, and we are investigating whether normal B-cells may be infected by HIV using C'-ADE mediation.

Keywords: AEGIS, HIV Infections, Complement, Herpesvirus 4, Human, Cell Line, Transformed, HIV Antibodies, Antigens, CD4, HIV, HIV Core Protein p24, HIV Antigens, Receptors, Complement, HIV Envelope Protein gp41, HIV Envelope Protein gp120, B-Lymphocytes, Receptors, Antigen, B-Cell, Antibodies, Monoclonal, Paris, France, Human, ICA6

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