Mechanisms of helper T cell response controlling by cytokines

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 05671840
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Biological pharmacy
• Research Institution: Kitasato University, School of Science
• Principal Investigator: KUMAZAWA Yoshio Kitasato Univ., School of Sci., Professor, 理学部, 教授 (30072375)
• Project Period (FY): 1993 – 1994
• Keywords: LPS / Anti-CD3 (epsilon) mAb / RT-PCR / IFNgamma / IL-4 / IL-10 / Cytokine / Macrophage

Research Abstract

In a previous study we showed that C57BL/10ScCr (LPS-nonresponder ; B10Cr) spleen cells produced less amounts of IFNgamma than C57BL/10ScSn (LPS responder ; B10Sn) spleen cells, stimulated in vitro with heat-killed Salmonella typhimurium. To make clear the difference in IFNgamma production between B10Sn and B10Cr spleen cells, they were stimulated in vitro with concanavalin A (Con A) or via T cell receptor (TCR) such as anti-CD3 (epsilon) mAb. The mRNA expression of IFNgamma and IL-4 reached at a peak 24 hr after stimulation. No difference in IFNgamma and IL-4 mRNA expression between B10Sn and B10Cr T cells was observed, although B10Sn T cells, stimulated with ConA for 3 days', produced higher amounts of IFNgamma than B10Cr. Preferential expression of IL-10mRNA in B10Cr T cells stimulated was not observed, indicating that selective activation of type-2 heper T (Th2) cells did not occur in B10Cr T cells. To estimate contribution of monokines to T cell activation, two types of macrophages were used ; one is bone marrow-derived macrophages obtained from cultures in the presence of M-CSF and the other is activated macrophages recovered from peritoneal cavity of mice injected with OK-432 4 days previously. They were stimulated in vitro with either S.abortus-equi LPS or OK-432. When stimulated with LPS,both types of B10Sn macrophages expressed TNFalpha mRNA and produced significant amounts of TNFalpha but B10Cr macrophages did not. In cultures of B10Sn macrophages, it was shown that LPS contaminated in fetal calf serum rendered enough signals to macrophages. Since 1) comparable amounts of TNFalpha were produced in both B10Sn and B10Cr macrophages when stimulated with OK-432 and 2) the location of IFNalpha/beta genes is very near to the Lps locus, it was suggested that gene products controled by theLps locus may regulate IFNgamma production by T cells.