Most Th2 clones, when activated, produce IL-4 and express CD40 ligand (CD40L) on their cell surface. Therefore, they can induce growth and differentiation of B cells by cognate help. In contrast, activated Th1 clones, which produce IFN-gamma and express both CD40L and Fas ligand (FasL) on their cell surface, often induce B cell apoptotic cell death. To understand the mechanism by which Th2 cells can induce B cell growth and differentiation in the presence of FasL-positive cells, we stimulated B cells with IL-4, anti-IgM and/or anti-CD40 in the presence of anti-Fas. We report here that addition of anti-Fas strongly inhibited anti-CD40-induced B cell proliferation without affecting anti-IgM-induced B cell proliferation. Furthermore we showed that stimulation of B cells with anti-CD40 induced the expression of Fas molecules on the B cells (approximately 30%) and rendered them highly sensitive to anti-Fas-mediated apoptotic cell death. Indeed, over 23% of anti-CD40-stimulated B cells showed hypodiploid DNA after being incubated with anti-Fas, while h2 cells could dominate over FasL-positive Th1 cells by production of CD40L and IL-4, which in combination induce antibody production and inhibit the Th1 cell-mediated immune response.
The effects of anesthesia and surgery on neutrophil count, chemotaxis and neutrophil alkaline phosphatase (NAP) score were investigated in 10 patients who had elective spine surgery. Plasma levels of adrenaline, noradrenaline and cortisol were measured and correlations between hormonal levels and neutrophil count and function were assessed. Neutrophil count started increasing after the initiation of surgery, reached the highest level at 3 hours after surgery, and decreased gradually toward preanesthetic level on 3rd postoperative day. The increase in band cell: segment cell ratio is prominent, whereas lymphocytes decreased significantly. Neutrophil chemotaxis and spontaneous migration were increased significantly from the end of operation to 1st postoperative day. NAP score, assumed to reflect the neutrophil phagocytic activity, lowered transiently during anesthesia, then increased 1.6 times more than preanesthetic level on 1st postoperative day. It was indicated that the increased cortisol release rather than adrenaline due to body response to surgical stress might induce neutrophilia, and that the elective spine surgery might not be deleterious to the neutrophil function.
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