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Requirements for Phytohaemagglutinin Activation of Resting Pure CD4 + and CD8 + T Cells
Author(s) -
LEIVESTAD T.,
HALVORSEN R.,
GAUDERNACK G.,
THORSBY E.
Publication year - 1988
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1988.tb02384.x
Subject(s) - phytohaemagglutinin , stimulation , cd8 , interleukin 2 , microbiology and biotechnology , receptor , dna synthesis , biology , t cell , antigen , chemistry , immunology , in vitro , endocrinology , immune system , biochemistry
We have utilized a new method for obtaining highly purified cells using positive selection by immunomagnetic separation to study the conditions required for phytohaemagglutinin (PHA) activation of pure T4 and T8 cells. In the presence of accessory cells (AC), a comparable proliferative response was obtained in the two subsets. In the absence of AC, PHA induced low levels of interleukin 2 (IL‐2) receptor expression as well as responsiveness to IL‐2 in both T4 and T8 cells. If AC or 12‐ O ‐tetradecanoyl‐phorbol‐13‐acctate (TPA) were also present, IL‐2 production and DNA synthesis were seen in both subsets. A short preincubation with PHA primed' T fells for subsequent responsiveness to IL‐2 or TPA, while preincubation with TPA did not induce response to PHA. Thus, PHA alone is sufficient for the first step of T cell activation lending to IL‐2 receptor expression. The second step leading to IL‐2 production, is dependent on direct interaction with AC in the presence of PHA. While T8 cells are dependent on help by T4 cells for proliferation to occur during stimulation with antigen, in PHA stimulation the requirements for activation and proliferation seem to he identical for T4 and T8 cells.