IL-4 PRODUCTION IN MEDIASTINAL LYMPH-NODE CELLS IN MICE INTRATRACHEALLY INSTILLED WITH DIESEL EXHAUST PARTICULATES AND ANTIGEN

To clarify the relationship between air pollutants and IgE antibody pr oduction, interleukin 4 (IL-4) production was investigated in BALB/c m ice intratracheally injected with diesel exhaust particulates (DEP) mi xed with antigen (Ovalbumin (OA) or Japanese Ceder Pollen (JCP)). BALB /c mice were injected with DEP plus OA or OA alone three times with a 3-week interval. After the last instillation, proliferative response a nd lymphokine-producing activity of mediastinal lymph node cells (LNC) were examined in vitro. Proliferative response to OA in mediastinal L NC from mice injected with DEP plus OA was enhanced 4-17 times of that from control mice. IL-4-producing activity by OA stimulation also enh anced in mediastinal LNC from mice injected with DEP plus OA. A signif icantly larger amount of anti-GA IgE antibody was detected in sera fro m DEP- and OA-injected mice compared with those from control mice. The levels of IL-4, estimated by JCP antigen in mediastinal LNC, from mic e injected with DEP plus JCP were two-fold higher than those from mice injected with JCP alone. These results suggest that intratracheal ins tillation of DEP affects antigen-specific IgE antibody responses via l ocal T-cell activation, especially enhanced IL-4 production.