Antibody-forming response of cultured spleen cells to a protein antigen: function of antigen presenting cells in SAMP1 mice

Abstract

SAMP1 and C3H/He mice were immunized with one or two intraperitoneal injections of ovalbumin (OVA) with alum adjuvant. Spleen cells from immunized as well as unprimed naı̈ve mice were cultured with OVA for 7 or 14 days. We observed little anti-OVA antibody response when spleen cells from unprimed naive mice were cultured with OVA. A small but substantial amount of OVA-specific IgG antibody was produced regardless of the presence of OVA in both C3H/He and SAMP1 spleen cell cultures when the donor mice had received a single OVA injection. OVA-specific IgG and IgA antibody responses induced by OVA added to cultures were clearly observed when the donor mice were immunized with two OVA injections. However, the antibody response of SAMP1 cells was much lower than that of C3H/He cells. It is possible that immune memory generation in SAMP1 mice is impaired. However, the concentration of IgG antibody against OVA in the peripheral blood of OVA-primed SAMP1 mice was as high as that of C3H/He mice. The depletion of adherent cells from the OVA-primed C3H/He spleen cells markedly reduced the OVA-specific IgG and IgA antibody responses, which were almost completely restored by adding peritoneal adherent cells from either C3H/He or SAMP1 mice to the culture. These results suggest that a defect in Th2 cells from SAMP1 mice is generally observed in the antibody response to T-dependent antigens. Furthermore, the antigen-presenting function of SAMP1 adherent cells is not impaired and is not involved as a major cause in the defective antibody-producing response to T-dependent antigens.