Suppression of IgE antibody response in mice by a naphthalene derivative, TEI-6472

Abstract

In the present report, we investigated suppressive effects of a naphthalene derivative, (7E)- N-(2-carboxyphenyl)-8-(2-naphthyl)-5,6-trans-5, 6-methano-7-octenamide L-lysine salt (TEI-6472), on in vitro and in vivo antigen-specific IgE response. Anti-trinitrophenyl (TNP) IgE response induced in vitro in TNP-keyhole limpet hemocyanin (KLH)-primed murine spleen cells was suppressed by about 60% in the presence of 10 −6 M TEI-6472. On the other hand, anti-TNP IgG1 and IgM response were not significantly suppressed under the same conditions. Proliferative responses of BALB/c spleen cells stimulated by lipopolysaccharide, concanavalin A or allogeneic spleen cells were not inhibited by TEI-6472 at 10 −6-10 −5 M. Interleukin 4 production from helper T-cell clone, D10.G4.1 was suppressed only slightly (less than 20%) at 10 −6 M TEI-6472. This compound was also effective in suppressing secondary anti-TNP IgE response in mice that were immunized twice with TNP-KLH and alum. When 10–20 mg/kg/day TEI-6472 was administered s.c. for 5 consecutive days starting from one day before the first and the second immunization, secondary anti-TNP IgE response was inhibited most strongly (40–45%). Anti-TNP IgG1 response was also inhibited but to a smaller extent (20–24%), while anti-TNP IgM response was suppressed only slightly (0–15%). These results suggest that, under appropriate conditions, TEI-6472 can suppress IgE responses more preferentially both in vitro and in vivo.