Functional modulation of CD8+ T cell by approved novel immune enhancer: Nocardia rubra Cell-Wall Skeletons (Nr-CWS)

Nocardia rubra cell wall skeleton (Nr-CWS) has been reported to have innate immunostimulating and anti-tumor activities. However, the immunomodulatory effects of Nr-CWS on CD8+ T cells and their related mechanisms are still unknown. In this work, our team purified CD8⁺T cells from spleen cells and explored the phenotype and function of NR-CWS in vitro on CD8⁺T cells. We observed that Nr-CWS can significantly up-regulate the expression of CD69 and CD25 on CD8⁺T cells, with no significant effect on apoptosis or cell death of CD8⁺T cells that occurs in vitro during culture. In addition, the effect of perforin and granzyme B was increased after Nr-CWS treatment, but did not substantially alter the expression of TRAIL and FasL. A variety of cytokine analyses have shown that of the cytokines examined (IFN-γ, TNF-α, IL-2, IL-4, IL-5, IL-6 and IL-10), only IFN-γ and TNF The increase in -α was more pronounced, and the effect of Nr-CWS in CD8⁺T cell culture medium on CD8+ T cells was independent of Th cells. Our results demonstrated that Nr-CWS could up-regulate CD69 and CD25 expression on CD8⁺T cells, promoting IFN-γ and TNF-α secretion, and enhancing perforin and granzyme B production. Thus Nr-CWS may have Immunoaugmenting therapeutic activity via an increase in CD8⁺T cells response.