A Study Of Intestinal Fungal Flora And Fungal Toxic Factors Changes And Intestinal Mucosal Damage In HIV-Infected People

Objective: By comparing the differences of intestinal fungal flora,fungal secreted toxic proteins,immune barrier and mechanical barrier between asymptomatic HIV-infected people who have not yet developed to AIDS and HIV-negative people,we tried to analyze the correlation among intestinal fungal flora,toxic factors,and immune status,and investigate the possible correlation between intestinal fungal microecological changes and intestinal mucosal damage in HIV-infected people.Methods: All subjects were divided into group A,group B and control group.Untreated asymptomatic HIV-infected people after diagnosis were in group A,asymptomatic HIV-infected people with standard antiviral treatment after diagnosis were in group B and HIV-negative people were in control group.We collected stool specimens and blood specimens of all the subjects to analyze intestinal fungal flora distribution by high throughput sequencing of fungus ITS1,to analyze the expression of intestinal fungal secreted toxic protein gene,which concluding Agglutinin-like sequence3(ALS3),Hyphal wall protein 1(HWP1),Phospholipase-B1(PLB1),Polystyrene adhesion enhancer protein 1(EaP1),Secreted aspartylproteinases(SAPs),by RT-qPCR technology,to detect the cellular immune status,which including CD4+T cells(CD4),CD4+T cell percentage(CD4%),by flow cytometry,to detect the contents of markers of intestinal mucosal mechanical barrier damage in the serum,which including Intestinal fatty acid binding protein(I-FABP),D-Lactata(D-La)and Lipopolysaccharide(LPS),by enzyme-linked immunosorbent assay.The basic information and the differences of indicators among the three groups were compared by chi-square test,variance analysis and kruskal-wallis analysis,and correlation of indictors was analyzed by Spearman with SPSS 22.0.Fungal flora information was analyzed with Qiime software(Version 1.9.1)and R software(Version2.15.3).P < 0.05 was considered statistically significant.Result: 1.Intestinal fungal flora distribution: There were no significant differences at the richness of intestinal fecal fungal flora(Alpha diversity)in three groups.The composition of intestinal fecal flora(Beta diversity)was significant different.The relative abundance of Saccharomycetes,Saccharomycetales,Candida albicans are significant different,especially gathered in group A.The relative abundance of Fiobasidiales,Cutaneotrichosporon,Lecanicillium-fungicola are significant different,especially gathered in group B.2.The amount of fungal secreted toxic protein gene: SAP1 in group A(P=0.024)and group B(P=0.026)was significantly higher than that in control group.3.Cellular immunity: CD4 was significantly lower in group A(P < 0.001)and group B(P=0.003)than that in control group.CD4% was significantly lower in group A(P < 0.001)and group B(P < 0.001)than that in control group.There were no statistical differences of CD4(P=0.462)between group A and group B.CD4% was significantly lower in group A(P=0.031)than group B.4.Injury mrkers of intestinal mucosal mechanical barrier damage in serum: There were no statistical differences of I-FABP and D-lactata among groups,and LPS in group B was significantly lower than that in control group(P=0.008).5.Correlation between intestinal fungal flora and fungal secreted toxic proteins: Candida was positively correlated with SAP1(P=0.045,r=0.33).6.Correlation between intestinal fungal flora and cellular immunity: There was no obvious correlation between intestinal fungal flora and CD4 and CD4%.7.Correlation between fungal secreted proteins and immune status: There was no significant correlation between the secreted proteins of Candida and host CD4 and CD4%.Conclusion: 1.Intestinal fungal flora structure and secreted toxic factors have changed in HIV-infected people who have not yet developed to AIDS before they had symptoms of digestive tract,and ART treatment did not significantly slow the change.2.Compared to HIV-negative people,Candida and Candida albicans significantly increased in the intestinal tracts of asymptomatic HIV-infected people,especially in the intestinal tracts of untreated HIV-infected people.3.Compared to HIV-negative people,the mRNA expression of SAP1 of Candida albicans in the intestinal tract of HIV-infected people was significantly increased.4.There was no significant correlation between intestinal fungal flora distribution and toxic factors secreted by Candida albicans and cellular immunity of host cells.