AEGiS-11IAC: Exploration of mucosal immunity in HIV-1 infection and its application to vaccine trials.

11th International AIDS Conference

Vancouver, British Columbia — July 7-12, 1996

Exploration of mucosal immunity in HIV-1 infection and its application to vaccine trials.

Int Conf AIDS 1996 Jul 7-12; 11:14 (abstract no. We.A.394)
Finkielsztejn L, Salmon D, Excler JL, Blondeau C, Raux M, Bouchez H, Renaudie C, Belec L, Meillet D, Sicard D; Hopital Cochin, Medecine Interne, Paris, France. Fax: 33-1-43 26 88 92. E-mail: Laufink@pratique.fr.

OBJECTIVES: To develop and standardize sampling methods and HIV-1 antibody measurements at mucosal sites in HIV-1 infected and non-infected subjects in order - to determine cut-offs and magnitude of the immune response. Subjects: 17 HIV-1 positive CDC II/III (mean CD4 cell count: 536 plus or minus 198/mm3) and 19 HIV-negative controls volunteers.

METHODS: Total IgG and IgA, IgG and IgA to gp120-MN and p24-LAI antibodies were measured by ELISA in serum comparatively to the following mucosal secretions: total, crevicular and parotid saliva (SA), and cervico-vaginal fluid (CV).

RESULTS: there was an important inter-individual variability in Ab titers in both SA and CV. IgG titers were higher than IgA in CV and higher in CV than in SA. Specific Ig were not detected in HIV-1 negative subjects. The % of HIV-1 positive subjects with specific Ab was as follows: (table: see text) Anti-p24 and gp120 specific activities in mucosal fluids equal to or lower than in serum and the presence of a correlation between Ig in serum and the different mucosal fluids, strongly suggest that most of the specific IgG and IgA in mucosal fluids are probably of transudative origin. Antibody response was measured in SA and CV in healthy subjects immunized with ALVAC-HIV (vCP205). One month post-4th injection, low anti-gp120 IgG titers were detected in CV in 4/5 and in saliva in 1/10 of them. Only 1/5 had anti-p24 IgG detected in CV. A strong correlation was found between serum and mucosal antibodies titers. None of them had detectable serum or mucosal specific IgA antibodies. In conclusion, sampling and titration methods at the SA and CV level have been standardized and can now be used to evaluate mucosal humoral responses in HIV/AIDS vaccines trials. The exploration of the immune response in the rectal and seminal compartments is under investigation.

Keywords: AEGIS, HIV Infections, Immunity, Mucosal, HIV-1, Immunoglobulin A, AIDS Vaccines, CD4 Lymphocyte Count, Immunoglobulin G, Saliva, Mucous Membrane, Enzyme-Linked Immunosorbent Assay, Female, immunology, ICA11

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WeA394