Objective To investigate the expression of NKG2D and related signaling molecules adaptor protein(DAP10) and extracellular signal-regulated kinase(ERK) in the inflammatory cells of gastric adenocarcinoma and para-carcinoma tissues,the effects of vasoactive intestinal peptide(VIP) on the expression of NKG2D,DAP10 and ERK in natural killer(NK) cells of healthy volunteers.Methods The expression of NKG2D,DAP10 and ERK in the inflammatory cells of 36 gastric adenocarcinoma and para-carcinoma tissues were detected by immunohistochemistry.The peripheral blood NK cells of healthy volunteers were isolated and purified with CDC method.The expressions of NKG2D,DAP10 and ERK in NK cells were determined by immunocytochemistry and reverse transcription-polymerase chain reaction(RT-PCR) methods before and after VIP intervention.The ttest was used for comparison between two groups and rank transformation nonparametric test (Kruskal-Wallis H test) for count data analysis.Results The expression levels of NKG2D,DAP10 and ERK in the inflammatory cells of gastric adenocarcinoma were significantly lower than those of para-carcinoma tissues (H=30.640,24.910,20.320,all P＜0.01).The expression levels of NKG2D,DAP10 and ERK were much lower in poorly differentiated gastric adenocarcinoma (H =4.049,11.830,8.118),at stage Ⅲ-Ⅳ (H=4.275,11.560,7.686),and the expression levels of NKG2D,ERK were lower with lymph nodes metastasis (H=6.513,6.064,all P＜0.05).The expression levels of NKG2D,DAP10 and ERK in gastric adenocarcinoma tissues and inflammatory cells were not correlated with gender,age and the location of lesions (all P＞0.05).The expression levels of NKG2D,DAP10 and ERK in NK cells was decreased after VIP intervention (protein:H=12.438,4.798,13.745,mRNA:F=337.640,638.579,1055.015,all P＜0.05).Conclusion Gastric adenocarcinoma may downregulate the expression of NKG2D,DAP10 and ERK in NK cells through VIP secretion,which may be involved in the immune escape of gastric cancer.

Objective:To study immunosuppression mediated by the porcine FcγRⅢ in porcine reproductive and respiratory syndrome virus ( PRRSV ) infection to pulmonary alveolar macrophages ( PAMS ).Methods: In this study pulmonary alveolar macrophages cells were treated with containing 200 TCID50 PRRSV,lipopolysaccharide (LPS) (100 ng/ml) and purified mouse anti-pig FcγRⅢIgG (550 μg/ml) separately,simultaneously,PAM cells treated with purified mouse anti-pig FcγRⅢIgG (550 μg/ml) was infected by 200 TCID50 PRRSV ,untreated PAM cells as the control group.Each group were post-cultured 12,24,36,48,60,72 h, the cells and the supernatant were collected.The dynamic variation of PRRSV RNA copies in inoculation group were detected by using real-time fluorescence quantitative PCR method.mRNA level of IFN-αand TNF-αin each group were detected by using relative fluorescence quantitative PCR.Results:The result showed that mRNA level of IFN-αwas improved during PRRSV infection to PAMS 12-24 h,and mRNA level of IFN-αwas inhibited during 36-72 h,then mRNA level of IFN-αrecovered normally; mRNA level of TNF-αwas increased slightly post-infection 12-72 h.IFN-αand TNF-αmRNA levels of PAM cells treated with LPS were both up-regu-lated,using the purified mouse anti-pig FcγRⅢ IgG to treat the PAM cells,selective activation of porcine FcγRⅢ in the PAM cells down-regulated significantly mRNA levels of IFN-αand TNF-α.PRRSV infection assay mediated by selective activation FcγRⅢof the PAM cells inhibited antiviral cytokine ( IFN-αand TNF-α) mRNA levels.Conclusion:The results show selective activation of FcγRⅢinhibited significantly mRNA levels of the antiviral cytokine IFN-αand TNF-αof host cells,and innate antiviral immune response to PRRSV infection.

Objective: To investigate the positive rate for 2019-nCoV tests and co-infections in Wuhan district. Methods: A total of 8 274 cases in Wuhan were enrolled in this cross-sectional study during January 20 to February 9, 2020, and were tested for 2019-nCoV using fluorescence quantitative PCR. Both respiratory tract samples (nasopharynx, oropharynx, sputum and alveolar lavage fluid) and non-respiratory tract samples (urine, feces, anal swabs, blood and conjunctival sac swabs) were collected. If both orf1ab and N genes are positive, they are classified as nucleic acid test positive group; if both orf1ab and N genes are negative, they are classified as negative group; if single gene target is positive, they are classified as suspicious group. Individuals were divided into male group and female group according to sex. At the same time, 316 patients were tested for 13 respiratory pathogens by multiplex PCR. Results: Among the 8 274 subjects, 2 745 (33.2%) were 2019-nCoV infected; 5 277 (63.8%) subjects showed negative results in the 2019-nCoV nucleic acid test; and 252 cases (3.05%) was not definitive (inconclusive result). The age of cases with COVID-19 patients and inconclusive cases was significantly higher than that of cases without 2019-nCoV infection (40 vs 56, t=27.569, P<0.001; 52 vs 56, t=6.774, P<0.001). The positive rate of 13 respiratory pathogens multiple tests was significantly lower in 104 subjects who were positive for 2019-nCoV compared with those in subjects who were negative for 2019-nCoV test (5.77% vs 18.39%, χ²=24.105, P=0.003). Four types of respiratory tract samples and five types of non-respiratory tract samples were found to be positive for 2019-nCoV nucleic acid test. Conclusion The 2019-nCoV nucleic acid positive rate in male is higher than in female. Co-infections should be pay close attention in COVID-19 patients. 2019-nCoV nucleic acid can be detected in non-respiratory tract samples.