Circulating Th17 cytokine levels are altered in Hashimoto's thyroiditis.

The disrupted autoimmune response in Hashimoto's thyroiditis (HT) has long been considered to be dominantly T helper type 1 (Th1) mediated. Recent advances in the field of immunology have introduced a new class of effector T cells, named 'Th17', which plays important roles in autoimmune disorders once thought to be merely Th1 mediated. We aimed to examine the levels of major Th17 cytokines in patients with HT in this study. We studied serum interleukin 17 (IL-17) and interleukin 23 (IL-23) levels in 46 newly diagnosed, untreated patients with HT (40 women and 6 men, aged 40.0 ± 11.8 years) divided into euthyroid (n=22) and hypothyroid (n=24) groups and compared them with age and sex matched 26 healthy euthyroid controls without HT (21 women and 5 men; aged 36.0 ± 12.9 years). Serum IL-17 and IL-23 levels were significantly different among euthyroid and hypothyroid HT patients and controls, with highest levels obtained in the euthyroid HT group (p=0.041 for IL-17 and p<0.001 for IL-23). TSH was negatively and FT4 was positively correlated with IL-17 (p=0.016 for TSH and p=0.004 for FT4) and IL-23 (p<0.001 for TSH and p=0.003 for FT4) levels. There were no correlations between thyroid volumes calculated on thyroid ultrasonography and IL-17 (p=0.630) or IL-23 (p=0.321) levels. In conclusion, the levels of IL-17, one of the major effector cytokines of the Th17 system, and IL-23, which had been implicated in the generation, survival and expansion of Th17 cells, are altered in HT. How thyroid hormone status and the course of disease affect Th17 system in chronic autoimmune thyroiditis needs to be determined with further studies.

In vitro effects of Candida albicans and Aspergillus fumigatus on dendritic cells and the role of beta glucan in this effect.

BACKGROUND: Dendritic cells (DCs) are able to initiate and regulate the immune response to fungal infections. ß-glucan stimulates the immune system, modulating cellular and humoral immunity. It has a beneficial effect in fighting fungal infections. OBJECTIVES: We investigated the in vitro effect of C.albicans and A.fumigatus infection on human DCs. The cytokine levels were determined by ELISA. MATERIAL AND METHODS: Human PBMCs isolation was performed by Ficoll-hypaque density gradient centrifugation method. DCs maturation was analysed by using flow cytometry. The cytokine levels were determined by ELISA. RESULTS: DCs stimulated by C. albicans and A. fumigatus induced DC maturation by increasing CD80 and CD86 co-stimulatory molecules. DCs stimulated by fungi produced IL-8 and IL-12p70. Whereas IL-10 production from the stimulated DCs did not differ from uninfected DCs. Also, the addition of ß-glucan to the DCs stimulated by fungi promoted the activation and maturation of DCs. CONCLUSIONS: Our results suggest that DCs are capable of initiating an innate and adaptive immune response against fungal infections. In addition, ß-glucan can be used as a novel stimulator to DC-based vaccination against fungal infections.

Immunomodulatory effects of voriconazole and caspofungin on human peripheral blood mononuclear cells stimulated by Candida albicans and Candida krusei.

BACKGROUND: Candida infections are frequently associated with high morbidity and mortality rates in immunosuppressed patients. T cell-mediated and phagocytic immunity are the primary protective immune responses against fungal infections. Antifungal agents such as voriconazole and caspofungin enter phagocytic cells and lead to various intracellular activities. In this study, the authors aimed to investigate the immunomodulatory effects of voriconazole and caspofungin on human peripheral blood mononuclear cells (PBMC) stimulated by Candida albicans and Candida krusei. METHODS: Human PBMC isolation was performed by Ficoll-hypaque density-gradient centrifugation method. Cell proliferation was assessed by colorimetric method using MTT. The cytokine levels in the human PBMC culture supernatants stimulated by C. albicans and C. krusei were determined by enzyme-linked immunosorbent assay. RESULTS: The addition of voriconazole and caspofungin lead to proliferation of PBMC. In the presence of voriconazole and caspofungin, the levels of IL-2, IFN-γ and IL-6 remarkably increased in PBMC stimulated by C. albicans and C. krusei. However, the combination of antifungal drugs and PBMC stimulated by Candida species did not increase the levels of TGF-ß and IL-10. CONCLUSIONS: The results indicate that voriconazole and caspofungin have immunomodulatory effects on human PBMC stimulated by Candida species. The interaction between antifungal drugs and PBMC stimulates Th1-type cytokine secretion. Cytokine stimulation from immune cells can assist in the elimination of fungal pathogens. Therefore, during the treatment of fungal infection, putative immunomodulatory effects of antifungal agents should be taken into account.

Cytokine profile in murine toxoplasmosis.

OBJECTIVE: To investigate which cytokines are produced after acute infection of mice with Toxoplasma gondii (T. Gondii) RH strain. METHODS: Mus domesticus domesticus mice in infected group were inoculated with with highly virulent T. Gondii RH strain by intraperitoneally. Serum samples were obtained from infected and non-infected mice for cytokine levels for ELISA assay. RESULTS: The concentrations of tumor necrosis factor-α, interferon-γ, interleukin (IL)-10 and IL-12 in the cardiac blood sample of the infected mice were significantly higher than those in uninfected controls (P<0.05). The levels of transforming growth factor-1ß decreased in mice infected with T. gondii compared to those of the controls, the decrease was statistically significant (P<0.05). No significant difference was observed in levels of IL-4 between infected and healty control groups (P>0.05). CONCLUSIONS: According to our findings, immune response into T helper type 1 was predominant during acute T. gondii infection. Further characterization and purification of Toxoplasma molecule(s) implicated in the regulation of cytokines could lead to the development of new drug prospects to control Toxoplasma infection.

[Investigation of West Nile virus seroprevalence in healthy blood donors]. / Saglikli kan vericilerinde Bati Nil virusu seroprevalansinin arastirilmasi

West Nile virus (WNV) which is a flavivirus transmitted by mosquitos, may lead to asymptomatic infection, mild febrile illness or encephalitis. Many sporadic cases and major outbreaks of West Nile fever have been reported worldwide, however, WNV infections have not been well documented in Turkey. The aim of the present study was to determine the prevalence of past WNV infections in a population of blood donors. Blood samples were collected from donors with their informed consent. Samples were processed and tested for WNV IgG by enzyme-linked immunosorbent assay (ELISA) (Euroimmun, Germany) according to the manufacturer's guidelines. Demographic data of the donors were recorded. A total of 2821 serum samples were tested. Among them, 28 samples were found to be WNV IgG positive (0.9%) and 41 of them were indeterminate (1.4%). Thus a total of 69 objects were considered to have encountered WNV (2.4%). All of the IgG positive samples (n= 69) and randomly-selected negative samples (n= 60) were re-analysed for the presence of viral RNA by a commercial real-time reverse transcriptase PCR (LightMix® Kit West Nile Virus, TIBMolbiol, Germany). West Nile virus RNA was not found in any of the samples. In conclusion, our data have supported the results of other studies indicating the presence of WNV infection in Turkey. Further larger scale studies are necessary to evaluate the possible risks of WNV infections in our country in terms of blood banking.

Effects of Saccharomyces boulardii on cytokine secretion from intraepithelial lymphocytes infected by Escherichia coli and Candida albicans.

Saccharomyces boulardii (S. boulardii) is a probiotic and used in the prevention or treatment of diarrhoea. Saccharomyces boulardii has many mechanisms to protect the host against diarrhoeal pathogens. It might modulate the immune system. In this study, the influence of S. boulardii on the secretion of cytokines from intraepithelial lymphocytes (IELs) infected with Escherichia coli (E. coli) and Candida albicans (C. albicans) was investigated in vitro. Cytokine levels were determined by enzyme-linked immunosorbent assay. The secretion of proinflammatory cytokines such as interleukin (IL)-1beta was decreased in the infected IELs incubated with S. boulardii, but different from it, anti-inflammatory cytokine levels such as IL-4 and IL-10, however, were found to be higher. These findings demonstrated that S. boulardii may have protective effects against diarrhoeal pathogens by reducing the proinflammatory response.

Expression of cell surface markers on methicillin resistant Staphylococcus aureus stimulated lymphocytes.

BACKGROUND & OBJECTIVE: Methicillin-resistant Staphylococcus aureus (MRSA) has gradually been increasing, new strategies in the treatment of MRSA infections are required. This depends on the understanding of the infection pathogenesis and the immune response. This study was therefore designed to determine the immune response which develops during MRSA infection and the role of chemokines in this response, and also to compare the results with the changes occurring after MSSA infection. METHODS: The expression of the surface markers of human lymphocytes stimulated by heat-killed MRSA or MSSA was analysed by flow cytometry. The chemokine levels in the lymphocytes culture supernatants stimulated or not stimulated by microorganisms were determined by ELISA. RESULTS: Human peripheral blood mononuclear cells (PBMCs) stimulated by MRSA the levels of CD4(+)CD25(+) regulatory T cells, CD69 expressions in the activated T lymphocytes, CD3(-)CD16(+)CD56(+) NK cells and the levels of MIP-1alpha, MIP-1beta, MCP-1 chemokines increased as compared to the cells not stimulated by MRSA. Although stimulation by MSSA caused an increase in CD25 expression after 24 h, the increase was found to be lower than the one caused by MRSA stimulation. The increase in CD69 expression was statistically significant compared to the cells stimulated by MRSA. Different from the cells stimulated by MRSA, no change was observed in the expressions of CD54 and CD3(-)CD16(+)CD56(+) NK cells in the cells stimulated by MSSA. INTERPRETATION & CONCLUSION: Our findings showed that cellular as well as humoral immunity are critical in MRSA infection and that T cell activation and the increase in chemokines may play a role in the regulation of immune response.

The efficiency of Viscum album ssp. album and Hypericum perforatum on human immune cells in vitro.

Viscum album L. ssp. album and Hypericum perforatum L. are used for the treatment of different diseases. In this study, the effects of these herbals on immune cells were assessed in vitro. The phagocytosis, candidacidal activity of neutrophils and adhesion function of epithelial cells were investigated. Also, the expression of the surface markers of lymphocytes was analyzed by flow cytometry. It was observed that V. album ssp. album increased phagocytic activity and candidacidal activity of neutrophils and decreased adhesion function of epithelial cells. We also observed that in human peripheral blood mononuclear cells stimulated by Viscum album L. ssp. album the levels of CD4(+)CD25(+) and CD8(+)CD25(+) T cells, CD69 expressions in the activated T lymphocytes and CD3(-)CD16(+)CD56(+) NK cells increased compared to the cells that were not stimulated by this herbal. Whereas CD4(+)CD25(+), CD8(+)CD25(+) T cells, CD 69 expression and CD3(-)CD16(+)CD56(+) Natural killer cells did not show any significant differences with the presence of Hypericum perforatum L. compared to the control group. Hypericum perforatum L. increased candidacidal activity of neutrophils and decreased adhesion function of epithelial cells. In the light of these findings, it is considered that these extracts may be used as an adjuvant treatment option for immune activation in immunosuppressed patients.

Effects of recombinant interferon-gamma on cytokine secretion from monocyte-derived macrophages infected with Salmonella typhi.

Salmonella typhi (S. typhi) is an important pathogen which causes typhoid fever. The cytokines released from the macrophages, playing a role in the host defense against Salmonella infection, are crucial in the defense against the infection. IFN-gamma provides a protection against Salmonella infection by developing macrophage activation in different mechanisms. This study was designed to investigate the effect of the recombinant IFN-gamma (rIFN-gamma) on the cytokines secreted from S. typhi stimulated macrophages. Macrophage isolation was done in the heparinized blood samples obtained from healthy people, and following the priming with rIFN-gamma for 72h the cells were stimulated by S. typhi and then the cytokine levels in culture supernatants were determined by enzyme-linked immunosorbent assay. It was observed that rIFN-gamma reversely increased the levels of IL-1, IL-2 the levels of which were decreased by S. typhi and that it increased TNF-alpha levels while suppressing the levels of antiinflammatory cytokines such as IL-10 and TGF-beta the levels of which were increased by S. typhi. Consequently, rIFN was observed to increase protective Th1 response by affecting the secretion of cytokine during S. typhi infection and it was considered to be a good target especially to prevent and treat invasive Salmonella infections.

Expression of the surface antigens of lymphocytes and the levels of cytokines in mice infected with Aspergillus fumigatus.

BACKGROUND: Aspergillus fumigatus (A. fumigatus) is an opportunistic fungus that causes invasive aspergillosis. Determining the immune changes during A. fumigatus infection and the factors leading to such changes clearly will make it possible to prevent the spread of the infection and to provide new strategies in the treatment of infection. Thus, the present study aims at determining the changes of lymphocyte surface antigens which develop during A. fumigatus infection and the role of cytokines in immune response. METHODOLOGY: The expression of the surface antigens of lymphocytes was analysed by flow cytometry and the cytokine levels were determined by ELISA in a mouse model of aspergillosis. RESULTS: It was observed that in mice infected by A. fumigatus the percentage of CD19+ B cells and the levels of IL-4 and IL-10 increased when compared to those in noninfected mice cells. CONCLUSIONS: These results suggest that Th2 type cytokines are important in the pathogenesis of A. fumigatus infection. Humoral immunity is considered to be effective during A. fumigatus infection because of the increase in Th2 type response.