title: Functional B cell abnormalities in HIV type 1 infection: role of CD40L and CD70.
abstract: Early in HIV-1 infection, B cell responses to T cell-dependent antigens are impaired. In addition to the receptor-ligand pair CD40/CD40L, CD27/CD70 also appears to be involved in T cell-dependent B cell stimulation. We have shown that CD70+ B cells are the main producers of Ig when stimulated in a T cell-dependent manner, and that CD70 upregulation is dependent on interaction of CD40L on T cells with CD40 on B cells. We confirm here that B cells from HIV-infected individuals are impaired in T cell-dependent Ig production in vitro. This dysfunction could partly be restored by adding allogeneic T cells to the culture. In contrast, IgG production induced by CD40 MAb, IgM MAb, and IL-10 was in the normal range. In line with this, CD70 upregulation on B cells from HIV-infected individuals was impaired after stimulation in vitro by activated T cells but not after stimulation with CD40 MAb and IgM MAb. Furthermore, CD40L expression was decreased on CD4+ T cells after stimulation in vitro. Finally, CD70 expression on freshly isolated B cells from HIV-infected individuals was decreased, and low CD70 expression correlated with low IgG production after T cell-dependent stimulation. In conclusion, our data strongly suggest that impaired B cell responses to T cell-dependent Ag in HIV-1 infection are due to a defect in T cells.
authors.affiliation: Department of Clinical Viro-Immunology, Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, University of Amsterdam.
authors.forename: K C
authors.initials: KC
authors.lastname: Wolthers
authors.forename: S A
authors.initials: SA
authors.lastname: Otto
authors.forename: S M
authors.initials: SM
authors.lastname: Lens
authors.forename: R A
authors.initials: RA
authors.lastname: Van Lier
authors.forename: F
authors.initials: F
authors.lastname: Miedema
authors.forename: L
authors.initials: L
authors.lastname: Meyaard
mesh_terms: D015703:Antigens, CD; D001402:B-Lymphocytes / Q000276:immunology*; D053282:CD27 Ligand; D019013:CD40 Antigens / Q000096:biosynthesis / Q000276:immunology; D023201:CD40 Ligand; D015331:Cohort Studies; D015483:HIV Antibodies / Q000096:biosynthesis / Q000276:immunology; D015658:HIV Infections / Q000097:blood / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000276:immunology*; D008565:Membrane Proteins / Q000096:biosynthesis / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D015703:Antigens, CD; D053282:CD27 Ligand; D019013:CD40 Antigens; C505771:CD70 protein, human; D015483:HIV Antibodies; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D023201:CD40 Ligand