Abstract:Background: Natural killer (NK) cells play important roles in the immune defense against tumors such as colorectal cancer. In humans, NKG2D is an activating immune receptor constitutively expressed in most cytotoxic lymphocytes including NK and CD8+ T cells. In this study, the expression of NKG2D molecule was investigated in peripheral blood NK cells from colorectal cancer patients and compared with healthy subjects. Methods: We studied 21 non-metastatic (low-grade), 17 non-metastatic (high-grade), 16 metastatic colorectal cancer patients, and 24 healthy controls. Peripheral blood samples were obtained to isolate peripheral blood mononuclear cells (PBMCs) and the percentage of peripheral blood NKG2D+CD3-CD56+ NK cells was analyzed by fl ow cytometry. The expression of NKG2D at mRNA level was also measured by real-time PCR in both, patients and control subjects. Results: The results showed a signifi cant reduction in the percentage of NKG2D+NK cells as well as NKG2D mRNA expression in peripheral blood of metastatic colon cancer patients. Conclusion: This result suggests that decreased expression of activating NKG2D receptor in metastatic colorectal cancer might compromise NK cell function and allow tumor to evade immunity (Tab. 3, Fig. 4, Ref. 33 Acknowledgements: Our thanks go to the vice chancellor for research, Isfahan University of Medical Sciences for supporting this research (project registration number: 189022). Also, we would like to thank all patients and healthy volunteers who participated in this study.

ObjectivesBrucellosis remains one of the most common zoonotic diseases worldwide. In humans, brucellosis can be a serious, debilitating, and sometimes chronic disease. Different mechanisms can be postulated as to the basis for the induction of the chronic status of infectious diseases that T regulatory cells are one of the most important related mechanisms. The current study was designed to determine whether percentage of CD4+Treg cells and their CD25high and FoxP3high subpopulations in peripheral blood are changed in human brucellosis samples in comparison to a control group.MethodsIn total, 68 brucellosis patients (acute form: n = 43, chronic form: n = 25) and 36 healthy volunteers entered our study. After isolating of peripheral blood mononuclear cells, heparinized venous blood samples were obtained from both patients and healthy donors, CD4, CD25, and FoxP3 molecules were evaluated by two- and three-color flow cytometric methods.ResultsThe results revealed a new finding in relation to Treg cells and human brucellosis. The numbers of CD4+Treg cells and their CD25high and FoxP3high subsets increase significantly in the peripheral blood of acute and chronic forms of brucellosis samples compared with healthy groups, with this increase being greater in the chronic group.ConclusionThere seems to be a correlation between increase of CD4+Treg cells and their subsets and the disease progress from healthy state to acute and chronic brucellosis.

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OBJECTIVE: Colorectal cancer (CRC) is one of the main causes of cancer deaths in the world. This cancer can be divided into non-metastatic and metastatic CRC stages. CD3+CD56+ NKT cell subsets are a minor T cell subset in peripheral blood and conduct the killing of tumor cells in direct manner. Little is obvious about levels and surface markers of these cells such as NKG2D in different cancers, especially in CRC. METHODS: We included 15 non-metastatic (low-grade), 11 non-metastatic (high-grade), 10 metastatic colorectal cancer patients and 18 healthy controls. The percentages of CD3+CD56+ NKT cells and NKG2D+CD56+ NKT cells from samples were analyzed by fl ow cytometry in peripheral blood mononuclear cells (PBMCs) of samples. RESULTS: We found that there was a signifi cantly lower number of NKG2D+CD3+CD56+ cells in peripheral blood of patients with metastatic colorectal cancer compared with normal controls (77.53 ± 5.79 % vs 90.74 ± 9.84 %; p<0.01). CONCLUSION: The fact that frequency of NKG2D+CD56+ NKT cells was signifi cantly lower in patients with metastatic colorectal cancer compared to healthy controls strengthens the hypothesis that NKT cells can play a substantial role in the protection against human colorectal cancer, and this opens up avenues for novel studies about elucidating the other aspects of tumor surveillance in CRC progression and immunotherapy (Tab. 2, Fig. 2, Ref. 46). Text in PDF www.elis.sk.

Background Acinetobacter baumannii has emerged as a major cause of nosocomial infections. Various resistance mechanisms of A. baumannii against antibiotics have transformed it into a successful nosocomial pathogen. Because of the limited number of available antibiotics, we used a medicinal plant with an antibacterial effect. Zataria multiflora Boiss (ZMB) extract and its components were used for the treatment of pneumonic mice infected with A. baumannii. The biological effects of this extract and the regulation of the outer membrane protein A (ompA) gene were used in a mouse model. Methods A pneumonic mouse model was prepared using clinical and standard strains (1.5 × 108 colony‐forming units/mL) of A. baumannii. BALB/c mice groups were treated with a ZMB extract, carvacrol, thymol, and sensitive antibiotics. The lung tissues of the treated mice were cultured for 5 days and each day, bacterial clearance and the ompA gene expression were assessed by quantitative real‐time polymerase chain reaction. Results In the lung tissue culture of pneumonic mice infected with standard or clinical isolate, no colony was detected when treated with the ZMB extract after 2 and 3 days (P < 0.01), respectively. In the carvacrol‐treated group, bacterial clearance was seen at day 4 and day 5 (P < 0.05). Bacterial clearance was seen 5 days after treatment with thymol and imipenem and 6 days after ampicillin/sulbactam treatment. The regulation of ompA gene was significantly decreased in this order: ZMB extract, carvacrol, thymol, imipenem, and ampicillin/sulbactam. Discussion The ZMB extract had a potent bactericidal effect against A. baumannii that could downregulate the ompA gene. ZBM extract and carvacrol could be novel therapeutic agents for antibiotic‐resistant A. baumannii.