Decrease of natural killer cell activity in patiens with cryptococcosis and its clinical significance
- Author:
Sun-Xiao CHEN
1
Author Information
1. Department of Dermatology and Venereology
- Publication Type:Journal Article
- From:
Academic Journal of Second Military Medical University
2006;27(2):120-124
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate the interactions between natural killer (NK) cells and Cryptococcus neoformans(C. neoformans) in patients with cryptococcosis, so as to pave a way for treatment and prevention of cryptococcosis. Methods: The peripheral blood samples of 40 cryptococcosis patients and 40 healthy controls were collected. Expression of CD2, CD3, CD4, CD8, CD28, CD18, CD19, and CD56 in patients peripheral blood mononuclear cells(PBMC) were detected by FACS. Cytotoxic activity of NK cells was analyzed by MTT using K562 cells as target cells and the influence of IFN-α and IL-2 on NK cell activity was also studied. The level of IFN-γ in the culture supernatant was assayed by ELISA and the cytotoxic activity of the supernatant was determined. The transcription levels of perforin, granzyme B and granulysin were examined by quantative real-time PCR. C. neoformans and NK cells were cocultured to investigate the inhibition of NK cells on C. neoformans. Results: Compared with that in healthy controls, CD56+ cells decreased significantly (P<0.01) in the PBMC of patients with cryptococcosis, CD8+,CD19+ and CD18+ cells increased significantly (P<0.05 or P<0.01),and the ratio of CD8+/CD28+ increased and of CD4+/CD8+ declined significantly (P<0.05). However, the levels of CD2+, CD3+ and CD4+ cells had no change. Compared with that in healthy controls, the NK cells cytotoxicity in patients with cryptococcosis decreased significantly(P<0.01), but increased when IFN-α or IL-2 was added (P<0.01). IFN-γ level in the PBMC supernatant of patients with cryptococcosis was much lower than that in healthy controls(P<0.01). Transcription of perforin, granzyme B and granulysin in PBMC of patients with cryptococcosis decreased markedly in contrast to those of healthy controls(P<0.01). The inhibitory effect of NK cells on growth of C. neoformans was significantly lower in cryptococcosis patients than that in healthy controls (P<0.05). Conclusion: The quantity and function of NK cells decrease in patients with cryptococcosis. Cytokines such as IL-2 and IFN-α can upregulate the cytotoxicity of NK cells, which suggests a new way for treatment of cryptococcosis.
