Significance of natural killer cell G2D expression and activation in patients with different immune status of chronic hepatitis B virus infection
	    		
		   		
		   			
		   		
	    	
    	 
    	10.3760/cma.j.issn.1000-6680.2017.01.002
   		
        
        	
        		- VernacularTitle:慢性乙型肝炎病毒感染者不同免疫状态下自然杀伤细胞G2D表达及其活化意义
 
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Yadong WANG
			        		
			        		;
		        		
		        		
		        		
			        		Wei WANG
			        		
			        		;
		        		
		        		
		        		
			        		Chuan SHEN
			        		
			        		;
		        		
		        		
		        		
			        		Li ZHANG
			        		
			        		;
		        		
		        		
		        		
			        		Xiaobo SHANG
			        		
			        		;
		        		
		        		
		        		
			        		Qianfei LIANG
			        		
			        		;
		        		
		        		
		        		
			        		Caiyan ZHAO
			        		
			        		
		        		
		        		
		        		
		        		
		        		
			        		
			        		
		        		
	        		
        		 
        	
        	
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Killer cells;
			        		
			        		
			        		
				        		natural;
			        		
			        		
			        		
				        		NKG2D;
			        		
			        		
			        		
				        		Hepatitis B virus;
			        		
			        		
			        		
				        		Hepatitis B;
			        		
			        		
			        		
				        		chronic;
			        		
			        		
			        		
				        		Acute-on-chronic liver failure
			        		
			        		
	        			
        			
        		
 
        	
            
            
            	- From:
	            		
	            			Chinese Journal of Infectious Diseases
	            		
	            		 2017;35(1):5-10
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	Objective To investigate the differences of expression and activation of natural killer (NK) cell G2D (NKG2D) in patients with different immune status of chronic hepatitis B virus (HBV) infection, and to explore the significance of NKG2D-mediated immune injury in HBV infection.Methods Fifteen chronic HBV carriers (immune tolerance),15 chronic hepatitis B (CHB, immune activation) patients, 15 HBV-related acute/subacute-on-chronic liver failure (HBV-ACLF, immune over-activation) patients were enro1led in this study from January 2010 to December 2011 in the Third Hospital of Hebei Medical University.The frequencies of NK cells and NKG2D+ NK cells in peripheral blood mononuclear cells (PBMC) were detected by flow cytometry.The NKG2D mRNA expressions were measured by real-time fluorescent quantitative polymerase chain reaction.Localization and hemi-quantitative analysis of NKG2D+ cells in liver tissue were performed by immunohistochemistry staining.Concentrations of serum interferon(IFN)-γ, tumor necrosis factor(TNF)-α, perforin and granzyme B were quantified by enzyme 1inked immunosorbent assay (ELISA).Normally distributed continuous variables were analyzed using one-way analysis of variance (ANOVA), followed by Student-Newman-Keuls q test for evaluating variances between each two groups.For non-normally distributed data or heterogeneity of variance, differences between groups were analyzed using nonparametric Kruskal-Wallis H test, followed by Nemenyi test for pairwise comparisons.Pearson chi-square test was used to analyze categorical variables.Results The percentages of NK cells in PBMC were (13.58±3.24)% in healthy controls, (5.42±2.18)% in chronic HBV carriers, (7.92±2.85)% in HBV-ACLF group and (8.43±2.92)% in CHB group.The percentage of NK cells in PBMCs was lower in each chronic HBV-infected group compared with healthy controls (F=22.04, P<0.05).The frequency of NKG2D+ NK cells in HBV-ACLF group (18.92±5.85)% was the highest, followed by CHB group (12.85±3.39)%, healthy controls (8.45±2.86)%, and chronic HBV carriers (3.36±1.05%), with the statistically significant differences between each two groups (H=46.09, P<0.01).Intrahepatic NKG2D mRNA expression and NKG2D+ cells density were highest in HBV-ACLF group (6.58±1.86 and 30.69±6.67, respectively), followed by CHB group (3.25±0.95 and 17.36±4.13, respectively) and chronic HBV carriers (0.69±0.20 and 3.16±1.24, respectively), with the statistically significant differences between each two groups (H=52.10 and 52.73 respectively, both P<0.01).The similar patterns were observed in serum IFN-γ, TNF-α, perforin and granzyme B concentrations.Conclusions NKG2D expresses variously in patients with different immune status of chronic HBV infection.Activation of NKG2D may take part in the immune pathogenesis of chronic HBV infection.