0000000000715643
AUTHOR
Helga Huhn
Cloned T helper cells reverting to a resting state develop increasing sensitivity in their antigen-mediated interaction with accessory cells.
A cloned murine T cell line, KIII5, specific for the polypeptide poly-L(Tyr,Glu)-poly-D,L-Ala--poly-L-Lys [(T,G)-A--L] was compared at different stages after antigenic stimulation with respect to the conditions required for the reinduction of growth by varying concentrations of antigen presented on different types of accessory cells (AC). We show that the dose of antigen necessary for inducing half maximal proliferation in the presence of splenic AC shifts to considerably lower concentrations when the T cell blasts revert to a resting state (100 micrograms/ml on day 7 to 10 micrograms/ml on day 21-35). During the same time period the expression of interleukin 2 (IL2) receptor and the reacti…
An antigen-independent physiological activation pathway for L3T4+ T lymphocytes.
The data presented in this report describe an antigen-independent activation pathway leading to reinduction of proliferation of class II major histocompatibility complex (MHC)-restricted murine T cell lines that after previous antigen-specific stimulation reverted to a resting state. Antigen-independent proliferation and interleukin 2 (IL2)-receptor expression occur in the presence of splenic accessory cells, exogenous IL2 and a soluble factor(s) provisionally termed T cell-stimulating factor(s) (TSF). Each of these components is essential for inducing growth. TSF is found in the supernatant of an autoreactive T cell line upon stimulation with syngeneic accessory cells. Neither TSF nor acce…
Involvement of soluble mediator(s) different from interleukin (IL)1 in the antigen-induced IL 2 receptor expression and proliferation of L3T4+ (CD4+) T lymphocytes
Proliferation of T lymphocytes (T cells) requires the interaction of interleukin 2 (IL 2) with the high affinity form of the IL 2 receptor (IL 2R). IL 2 production as well as IL 2R expression are generally induced simultaneously in T cells by the recognition of specific antigen displayed on the surface of syngeneic antigen-presenting cells. The experiments described herein show that the expression of IL 2R has different requirements than the production of IL 2 (and other lymphokines). Stimulation of antigen-specific L3T4+ T cell lines with antigen-pulsed spleen cells (SC) treated with ultraviolet (UV) light results in efficient IL 2 production but only minimal proliferation due to reduced I…