effects of candida albicans cell wall protein fraction on dendritic cell maturation

Candida albicans is a member of the normal human microflora. C. albicans cell wall is composed of several protein and carbohydrate components which have been shown to play a crucial role in C. albicans interaction with the host immune system. Major components of C. albican cell wall are carbohydrates such as mannans, beta glucans and chitins, and proteins that partially modulate the host immune responses. Dendritic cells [DC], as the most important antigen-presenting cells of the immune system, play a critical role in inducing immune responses against different pathogens. We investigated the effect of the cell wall protein fraction [CPF] of C. albicans on DC maturation. The CPF of C. albicans cells was extracted by a lysis buffer containing sodium dodecyl sulphate, 2-mercaptoethanol and phosphate-buffered saline. The extract was dialyzed and its protein pattern was evaluated by electrophoresis. Dendritic cells were purified from Balb/c mice spleens through a three-step method including mononuclear cell separation, as well as 2-h and overnight cultures. The purified CPF was added at different concentrations to DC. The purity and maturation status of DC were determined by flow cytometry using monoclonal antibodies against CD11c, MHC-II, CD40 and CD86. Treatment of DC with 10 micro g/ml of CPF increased the expression of maturation markers including MHC-II, CD86 and CD40 on DC compared to the control group. In this study we used C. albicans CPF with the molecular weight of 40-45 kDa for pulsing and maturation of dendritic cells. Since according to our results CPF significantly increased the expression of maturation markers on DC, we suggest that CPF may act as an efficient immunomodulator, or may be used as a potential adjuvant to boost the host immune system against infections

Effect of cell wall, cytoplasmic fraction and killed-Candida albicans on nitric oxide production by peritoneal macrophages from BALB/c mice

The fractions of Candida albicans have been used as an immunomodulator. The present work assessed the effect of different fractions of C. albicans on nitric oxide [NO] production by mice peritoneal macrophages. Cell wall and cytoplasmic fractions of C. albicans ATCC 10321 strain were extracted. Mice peritoneal macrophages were purified and cultured. Different concentrations of both fractions and also killed C. albicans cells were used for macrophages stimulation and evaluation of NO production. NO amount was detected in culture supernatants of macrophages by Griess reagent. Also, MTT assay was performed to assess the viability of macrophages. The results elucidated that suppressive effect of cell wall proteins on NO release was significant at the dose of 100 micro g/ml [P=0.01], while cytoplasmic fraction increased NO amount at the dose of 1 micro g/ml compared to the control group [P=0.003]. Augmentation of NO production was statistically significant at 200 killed C. albicans per well [P=0.006]. According to our findings, cytoplasmic fractions and killed C. albicans have a positive effect on NO production by peritoneal macrophages, while cell wall fractions did not. Therefore, it is proposed that C. albicans fractions can be studied more as inflammation modulators

Effect of shark liver oil on peritoneal murine macrophages in responses to killed-Candida albicans

Shark Liver Oil [SLO] is an immunomodulator. Macrophages play a key role in host defense against pathogens like fungi. Candida albicans have mechanisms to escape immune system. We determined the effect of killed-Candida on the in vitro viability of macrophages and the effect of SLO on augmentation of this potency. Peritoneal macrophages were separated and cultured [3-105/well]. At first, the effect of killed-Candida [200 cells/well] on macrophage viability was evaluated, using MTT test. Then, MTT was performed on macrophages stimulated with killed-Candida in the presence of SLO. Killed-Candida suppressed the ability of MTT reduction and hence macrophages viability [P=0.026], but addition of SLO [100 mg/ml] significantly enhanced cell viability [P=0.00]. So, SLO could neutralize the inhibitory effect of Candida. Simultaneous with cytotoxic effect of killed-Candida cells on macrophages viability, SLO augment macrophages viability. So, it can be applied in candidiasis as a complement