EXPRESSION OF CYTOKINE RECEPTORS IN RADIATION-INDUCED MICE THYMIC LYMPHOMA

EXPRESSION OF CYTOKINE RECEPTORS IN RADIATION-INDUCED MICE THYMIC LYMPHOMA Yi Shang1, 2, Shizuko Kakinuma2, Yoshiko Amasaki2, Mayumi Nishimura2, Yoshiro Kobayashi1, Yoshiya Shimada1, 2 (1Dept.Biomol.Sci., Facul. Sci., Toho Univ., 2Low Dose Radiat. Effects Res. Project. NIRS)\nDysregulation of cytokine receptor expression plays an important role in lymphomagenesis. Therefore, it is useful to examine the difference in expression of cytokine receptors between thymic lymphoma (TL) cells and normal thymocytes in order to identify the critical receptors for lymphomagenesis. TL was induced by exposure to split-dose X-irradiation (1.6 Gy x 4 times) in TL-susceptible C57BL/6N(B6) mice and TL-resistant C3H/HeN(C3H) mice. Expression of receptors for IL-2 family was compared on the mRNA level between TL cells and control thymocytes of both strains. In B6 mice, TL incidence was significantly higher (94.2%) than that in C3H mice (19.6%). Cytokine receptors such as IL-2Ralpha, IL-9R, IL-15R and common-c showed a markedly higher expression in TL cells compared to the control thymocytes. The IL-9R level was dramatically higher in B6 mice than that in C3H mice. These findings suggested a correlation between the expression of IL-9R and the TL-susceptibility in mice. Expression of these receptors at protein level and activation of the downstream kinases in signal transduction cascades are now undertaken.4th International Workshop of Kyoto T Cell Conferenc