Analysis of peripheral blood dendritic cells as a non-invasivetool in the follow-up of patients with chronic hepatitis C

Hepatitis C virus(HCV) has a high propensity to establish chronic infections. Failure of HCV-infected individuals to activate effective antiviral immune responses is at least in part related to HCV-induced impairment of dendritic cells(DCs) that play a central role in activating T cell responses. Although the impact of HCV on DC phenotype and function is likely to be more prominent in the liver, major HCV-induced alterations are detectable in peripheral blood DCs(pb DCs) that represent the most accessible source of DCs. These alterations include numerical reduction, impaired production of inflammatory cytokines and increased production of immunosuppressive IL10. These changes in DCs are relevant to our understanding the immune mechanisms underlying the propensity of HCV to establish persistent infection. Importantly, the noninvasive accessibility of pb DCs renders the analysis of these cells a convenient procedure that can be serially repeated in patient follow-up. Accordingly, the study of pb DCs in HCV-infected patients during conventional treatment with pegylated interferon and ribavirin indicated that restoration of normal plasmacytoid DC count may represent an additional mechanism contributing to the efficacy of the dual therapy. It also identified the pre-treatment levels of plasmacytoid DCs and IL10 as putative predictors of response to therapy. Treatment of chronic HCV infection is changing, as new generation direct-acting antiviral agents will soon be available for use in interferon-free therapeutic strategies. The phenotypic and functional analysis of pb DCs in this novel therapeutic setting will provide a valuable tool for investigating mechanisms underlying treatment efficacy and for identifying predictors of treatment response.

Intestinal dendritic cells change in number in fulminant hepatic failure

AIM:To investigate the change in intestinal dendritic cell(DC)number in fulminant hepatic failure(FHF).METHODS:An animal model of FHF was created.Intestinal CD11b/c was detected by immunohistochemistry and Western blot.Quantitative real-time polymerase chain reaction(PCR)was used to detect intestinal integrin-αm RNA expression.Intestinal CD83,CD86,CD74,CD3 and AKT were detected by immunohistochemistry,Western blot and PCR.Phosphorylated-AKT(p-AKT)was detected by immunohistochemistry and Western blot.RESULTS:In the FHF group[D-galactosamine(D-Galn)+lipopolysaccharide(LPS)group],the mice began to die after 6 h;conversely,in the D-Galn and LPS groups,the activity of mice was poor,but there were no deaths.Immunohistochemistry results showed that in FHF,the expression of CD11b/c(7988400±385941vs 1102400±132273,P<0.05),CD83(13875000±467493 vs 9257600±400364,P<0.05),CD86(7988400±385941 vs 1102400±13227,P<0.05)and CD74(11056000±431427 vs 4633400±267903,P<0.05)was significantly increased compared with the normal saline(NS)group.Compared with the NS group,the protein expression of CD11b/c(5.4817±0.77 vs 1.4073±0.37,P<0.05)and CD86(4.2673±0.69 vs 1.1379±0.42,P<0.05)was significantly increased.Itg-α(1.1224±0.3 vs 0.4907±0.19,P<0.05),CD83(3.6986±0.40 vs 1.0762±0.22,P<0.05)and CD86(1.5801±0.32 vs 0.8846±0.10,P<0.05)m RNA expression was increased significantly in the FHF group.At the protein level,expression of CD74in the FHF group(2.3513±0.52)was significantly increased compared with the NS group(1.1298±0.33),whereas in the LPS group(2.3891±0.47),the level of CD74 was the highest(P<0.05).At the gene level,the relative expression of CD74 m RNA in the FHF group(1.5383±0.26)was also significantly increased in comparison to the NS group(0.7648±0.22;P<0.05).CD3 expression was the highest in the FHF group(P<0.05).In the FHF,LPS and D-Galn groups,the expression of AKT at the protein and m RNA levels was elevated compared with the NS group,but there wasno statistical significance(P>0.05).The p-AKT protein expression in the FHF(1.54±0.06),LPS(1.56±0.05)and D-Galn(1.29±0.03)groups was higher than that in the NS group(1.07±0.03)(P<0.05).CONCLUSION:In FHF,a large number of DCs mature,express CD86,and activate MHC classⅡmolecular pathways to induce a T cell response,and the AKT pathway is activated.

Advanced subunit vaccine delivery technologies: From vaccine cascade obstacles to design strategies

Designing and manufacturing safe and effective vaccines is a crucial challenge for human health worldwide.Research on adjuvant-based subunit vaccines is increasingly being explored to meet clinical needs.Nevertheless,the adaptive immune responses of subunit vaccines are still unfavorable,which may partially be attributed to the immune cascade obstacles and unsatisfactory vaccine design.An extended understanding of the crosstalk between vaccine delivery strategies and immunological mechanisms could provide scientific insight to optimize antigen delivery and improve vaccination efficacy.In this review,we summarized the advanced subunit vaccine delivery technologies from the perspective of vaccine cascade obstacles after administration.The engineered subunit vaccines with lymph node and specific cell targeting ability,antigen cross-presentation,T cell activation properties,and tailorable antigen release patterns may achieve effective immune protection with high precision,efficiency,and stability.We hope this review can provide rational design principles and inspire the exploitation of future subunit vaccines.