Zinc status in proliferative response of T lymphocytes

The in vitro proliferation of T lymphocytes are highly susceptible to Zn deprivation and Cd addition. In order to define Zn status in T cell proliferation, toxicological and biochemical situation of Zn in proliferative response of T cells was investigated by use of mouse spleen cell cultures stimulated by T cell-mitogen, Con A. The inhibitory effect of Cd on T cell proliferation was protected specifically by Zn. The protection by Zn was effective when Zn was added within 16 h after Con A stimulation. Zn addition affected neither Cd content in cells nor induction of Cd-thionein. These findings indicate that Zn-dependent processes expressed before the S phase of cell cycle are critical for T cell proliferation and are targets susceptible to Cd. Moreover, electrophoretical analysis showed two unknown Zn-binding proteins (49 and 100 KD) induced in spleen cells incubated with Con A and radioactive Zn. These Zn-binding proteins may be associated with the Zn-dependent processes critical for T cell proliferation.