Nandi D, Gross J A, Allison J P
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
J Immunol. 1994 Apr 1;152(7):3361-9.
CD28, a cell surface molecule expressed on all murine T cells, plays a critical role in T cell activation. We show here that NK-1.1+ cells, a subpopulation of SCID splenocytes, and IL-2-activated NK cells express CD28, although at lower levels than alpha beta T cells. Optimal proliferation of highly purified asialo GM1+ NK cells from the SCID spleen was observed in response to stimulation with IL-2 and PMA, together with anti-CD28 or L-B7+ cells. Thus, in addition to IL-2, murine NK cells require CD28-mediated costimulatory signals for optimal proliferation. IL-2-activated NK cells produced enhanced levels of IFN-gamma and TNF in response to stimulation with anti-CD28 and PMA. On the other hand, we were unable to demonstrate that CD28 signaling had any effect on NK-mediated cytotoxicity. We conclude that the CD28 costimulatory pathway is functional in NK cells and plays an important role in their proliferation and cytokine production.
CD28是一种在所有小鼠T细胞上表达的细胞表面分子，在T细胞活化中起关键作用。我们在此表明，NK-1.1⁺细胞（SCID脾细胞的一个亚群）和IL-2激活的NK细胞表达CD28，尽管表达水平低于αβ T细胞。在用IL-2和PMA以及抗CD28或L-B7⁺细胞刺激时，观察到来自SCID脾脏的高度纯化的去唾液酸GM1⁺ NK细胞的最佳增殖。因此，除了IL-2之外，小鼠NK细胞还需要CD28介导的共刺激信号来实现最佳增殖。IL-2激活的NK细胞在受到抗CD28和PMA刺激时产生的IFN-γ和TNF水平升高。另一方面，我们无法证明CD28信号传导对NK介导的细胞毒性有任何影响。我们得出结论，CD28共刺激途径在NK细胞中起作用，并在其增殖和细胞因子产生中起重要作用。
