T cell immune response is correlated with fibrosis and inflammatory activity in hepatitis B cirrhotics

AIM： TO explore the relationship among interferon-γ （IFN-γ） activity, fibrogenesis, T cell immune responses and hepatic inflammatory activity. METHODS： Peripheral blood samples from a total of 43 hepatitis B cirrhotic patients （LC） and 19 healthy controls （NC） were collected to measure their serum levels of IFN-γ, interleukin-2 （IL-2）, soluble interleukin-2 receptor （sIL-2R）, interleukin-10 （IL-10） and three serological markers of fibrosis including hyaluronic acid （HA）, procollagen type III peptide （PIIIP）, and type iV collagen were measured using a double antibody sandwich ELISA. Also, serum total bilirubin （TB） and alanine aminotransferase （ALT） were measured by routine measures. RESULTS： The concentrations of serological markers of fibrosis in patients with active cirrhosis （ALC） were significantly higher than those in stationary liver cirrhosis （SLC） or NC groups. The levels of serological markers in HBeAg-positive patients were significantly higher than those in HBeAg-negative patients. In SLC and ALC patients, a negative linear correlation was found between IFN-γ levels and the serological markers of fibrosis. IFN-γ and IL-2 levels in the ALC group were significantly higher than those in the SLC and NC groups, but the statistical difference was not significant between the latter two. In contrast, IL-10 levels in the SLC group were significantly higher than that in the NC group, but no significant difference was found between SLC and ALC groups. The sIL-2R level was elevated gradually in all these groups, and the differences were significant. Positive linear correlations were seen between IFN-γ activity and ALT levels （r = 0.339, P 〈 0.05）, and IL-2 activity and TB levels （r = 0.517, P 〈 0.05）. sIL-2R expression was positively correlated with both ALT and TB levels （r = 0.324, 0.455, P 〈 0.05）, whereas there was no statistically significant correlation between IL-10 expression and serum ALT and TB levels （r = -0.102, -0.093, P 〉 0.05）. Finally, there was a positive correlation between IFN-γ and IL-2 levels. CONCLUSION： T cell immune responses are correlated with fibrosis and hepatic inflammatory activity and may play an important role in liver cirrhosis.

EFFECT OF ELECTROACUPUNCTURE ON RED BLOOD CELL IMMUNE AND T-CELL SUBGROUP IN THE RAT

In the present study, the effect of electroacupuncture (EA) on immune system was observed in the rat by using micro- whole blood direct immunofluorescence staining assay to detect changes of the peripheral blood T lymphocyte subgroup and employing red blood cell (RBC) C 3b receptor- yeast rosette test and red blood cell-IC rosette test to analyze erythrocytic immune function. Results showed that after EA of “Zusanli" (ST 36), CD+ 4, RBC-C 3bRR and RBC-ICR in the peripheral blood of the normal rats increased significantly while CD+ 8 had no any considerable changes and a positive correlation between CD+ 4 and RBC-C 3bRR was found. In immunosuppression model rats, the values of CD+ 4 and RBC-C 3bRR were obviously lower than those of the normal control group while CD+ 8 had no any striking changes; but after EA treatment, there were no evident differences between EA group and normal control group in the above-mentioned indexes. There were also no any significant differences between non-acupoint group and normal control group in those indexes. Results suggest that EA of “Zusanli" (ST 36) can raise T cell immune function and RBC adhesion function in both normal rats and immunosuppression model rats, both of which present a positive correlation.

Induced Th2 dominant immune response in APPswe, PSEN1dE9 transgenic mice after nasal immunization with an adenoviral vector encoding 10 tandem repeats of beta-amyloid 3-10

Immunotherapy for Alzheimer＇s disease （AD） is effective in improving cognitive function in transgenic mouse models of AD. Because the AN1792 [beta-amyloid （Aβ） 1-42] vaccine was halted because of T cell mediated meningoencephalitis, many scientists are searching for a nove） vaccine to avoid the T cell mediated immune response caused by the Aβ1-42. Importantly, the time when the immunization is begun can influence the immune effect. In this study, an adenovirus vaccine was constructed containing 10 x Aβ3-10 repeats and gene adjuvant CpG DNA. Transgenic AD mice were immunized intranasally for 3 months. After 10 × Aβ3-10 vaccine immunization, high titers of anti-Aβ42 IgG1 predominant antibodies were induced. In spatial learning ability and probe tests, the 10 × Aβ3-10 immunized mice showed significantly improved memories compared to control mice. The 10 × Aβ3-10 vaccine resulted in a robust Th2 dominant humoral immune response and reduced learning deficits in AD mice. In addition, the 10 × Aβ3-10 vaccine might be more efficient if administered before Aβ aggregation at an early stage in the AD mouse brain. Thus, the adenovirus vector encoding 10 × Aβ-10 is a promising vaccine for AD.

Downregulation of CD4+CD25+ regulatory T cells may underlie enhanced Th1 immunity caused by immunization with activated autologous T cells

Regulatory T cells （Treg） play important roles in immune system homeostasis, and may also be involved in tumor immunotolerance by suppressing Th1 immune response which is involved in anti-tumor immunity. We have previously reported that immunization with attenuated activated autologous T cells leads to enhanced anti-tumor immunity and upregulated Thl responses in vivo. However, the underlying molecular mechanisms are not well understood. Here we show that Treg function was significantly downregulated in mice that received immunization of attenuated activated autologous T cells. We found that Foxp3 expression decreased in CD4＋CD25＋ T cells from the immunized mice. Moreover, CD4＋CD25＋Foxp3＋ Treg obtained from immunized mice exhibited diminished immunosuppression ability compared to those from naive mice. Further analysis showed that the serum of immunized mice contains a high level ofanti-CD25 antibody （about 30 ng/ml, p〈0.01 vs controls）. Consistent with a role ofanti-CD25 response in the downregulation of Treg, adoptive transfer of serum from immunized mice to naive mice led to a significant decrease in Treg population and function in recipient mice. The triggering of anti-CD25 response in immunized mice can be explained by the fact that CD25 was induced to a high level in the ConA activated autologous T cells used for immunization. Our results demonstrate for the first time that immunization with attenuated activated autologous T cells evokes anti-CD25 antibody production, which leads to impeded CD4＋CD25＋Foxp3＋ Treg expansion and function in vivo. We suggest that dampened Treg function likely contributes to enhanced Thl response in immunized mice and is at least part of the mechanism underlying the boosted anti-tumor immunity.

Bronchial inflammatory profile in interferon-gamma-mediated immune response in asthma patients during airway response to cold stimulus

Objective:To evaluate the inflammatory pattern and the interferon(IFN)-γin the bronchial secretion of asthma patients in response to acute cold bronchoprovocation.Material and methods:We enrolled 42 patients with asthma.We assessed asthma by Asthma Control Test,the lung function by spirometry before and after the bronchodilator test,followed by collecting induced sputum.The next day,we collected exhaled breath condensate(EBC)and conducted a 3-minute isocapnic hyperventilation with cold air(IHCA),followed by collecting spontaneously produced sputum.Results:Group 1 included 20 patients with cold airway hyperresponsiveness(CAHR),and group 2 included 22 patients without CAHR.In both groups,a high level of neutrophils in bronchial secretion was observed before and after IHCA.In response to IHCA,the number of epitheliocytes in the sputum decreased to a greater extent in patients of group 1.The baseline epitheliocytes and the concentration of IFN-γafter IHCA had an inverse relationship(r=-0.60;P=0.017).The baseline IFN-γin EBC before and after IHCA was lower in group 1.Airway response to cold exposure directly correlated with IFN-γlevels after IHCA(Rs=0.42;P=0.014).Conclusion:In asthma patients with CAHR,there is a relationship between the persistence of mixed inflammation and the level of IFN-γin the bronchi.IFN-γin response to IHCA is decreased with increased cytokine utilization during cold bronchospasm,which is accompanied by the mobilization of neutrophils and the shift in the cytokine spectrum of the respiratory tract towards the T helper cells(Th)1 immune response.

Adaptive immune response during hepatitis C virus infection

Hepatitis C virus(HCV)infection affects about 170 million people worldwide and it is a major cause of liver cirrhosis and hepatocellular carcinoma.HCV is a hepatotropic non-cytopathic virus able to persist in a great percentage of infected hosts due to its ability to escape from the immune control.Liver damage and disease progression during HCV infection are driven by both viral and host factors.Specifically,adaptive immune response carries out an essential task in controllingnon-cytopathic viruses because of its ability to recognize infected cells and to destroy them by cytopathic mechanisms and to eliminate the virus by non-cytolytic machinery.HCV is able to impair this response by several means such as developing escape mutations in neutralizing antibodies and in T cell receptor viral epitope recognition sites and inducing HCV-specific cytotoxic T cell anergy and deletion.To impair HCV-specific T cell reactivity,HCV affects effector T cell regulation by modulating T helper and Treg response and by impairing the balance between positive and negative co-stimulatory molecules and between pro-and antiapoptotic proteins.In this review,the role of adaptive immune response in controlling HCV infection and the HCV mechanisms to evade this response are reviewed.

Conservation of T cell epitopes between seasonal influenza viruses and the novel influenza A H7N9 virus

A novel avian influenza A(H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian influenza virus subtypes such as H5N1 and H9N2. While there are other potential explanations for this large number of human infections with an avian influenza virus, we investigated whether a lack of conserved T-cell epitopes between endemic H1N1 and H3N2 influenza viruses and the novel H7N9 virus contributes to this observation. Here we demonstrate that a number of T cell epitopes are conserved between endemic H1N1 and H3N2 viruses and H7N9 virus. Most of these conserved epitopes are from viral internal proteins. The extent of conservation between endemic human seasonal influenza and avian influenza H7N9 was comparable to that with the highly pathogenic avian influenza H5N1. Thus, the ease of inter-species transmission of H7N9 viruses(compared with avian H5N1 viruses) cannot be attributed to the lack of conservation of such T cell epitopes. On the contrary, our findings predict significant T-cell based cross-reactions in the human population to the novel H7N9 virus. Our findings also have implications for H7N9 virus vaccine design.

Preventive effects of Bifidobacterium lactis Probio-M8 on ovalbumin-induced food allergy in mice

Food allergy is a significant public health concern globally.Certain probiotics have been found to enhance food allergy by regulating immune-microbe interactions in animal models and patients.However,the effects of Bifidobacterium lactis Probio-M8 on food allergy have not been thoroughly investigated.The present study examined the anti-allergic properties of Probio-M8,particularly in relation to immune response and gut microbiota composition.Results demonstrate that oral administration of Probio-M8 effectively mitigated the allergy symptoms triggered by ovalbumin(OVA)by ameliorating the morphological damage in the jejunum,reducing OVA-specific IgE and histamine levels in the serum,and suppressing Th2 cytokines(interleukin(IL)4 and IL-13)while increasing Th1 cytokines(interferon(IFN)γ)and regulatory T(Treg)cytokines(IL-10 and transforming growth factor(TGF)β1)in the culture supernatants of splenic cells.Furthermore,Probio-M8 effectively altered the diversity and composition of gut microbiota,particularly the relative abundances of Akkermansia_muciniphila in OVA-induced mice.Compared to the OVA group,the Probio-M8 group showed a decrease in the relative abundance of Akkermansia_muciniphila.In conclusion,Probio-M8 demonstrates the potential to alleviate food allergy by regulating the Th1/Th2 response and modulating gut microbiota,thereby offering a novel therapeutic strategy for patients with food allergy.

Regulation of T cell immunity by cellular metabolism

T cells are an important adaptive immune response arm that mediates cell-mediated immunity. T cell metabolism plays a central role in T cell activation, proliferation, differentiation, and effector function. Specific metabolic programs are tightly controlled to mediate T cell immune responses, and alterations in T cell metabolism may result in many immunological disorders. In this review, we will summarize the main T cell metabolic pathways and the important factors participating in T cell metabolic programming during T cell homeostasis, differentiation, and function.

MAP3K2 augments Th1 cell differentiation via IL-18 to promote T cell-mediated colitis

T cell-mediated immunity in the intestine is stringently controlled to ensure proper immunity against pathogenic microbes and to prevent autoimmunity,a known cause of inflammatory bowel disease.However,precisely how T cells regulate intestine immunity remains to be fully understood.In this study,we found that mitogen-activated protein kinase kinase kinase 2(MAP3K2)is required for the CD4^(+)T cell-mediated inflammation in the intestine.Using a T cell transfer colitis model,we found that MAP3K2-deficient naïve CD4^(+)T cells had a dramatically reduced ability to induce colitis compared to wild type T cells.In addition,significantly fewer IFN-γ-but more IL-17A-producing CD4^(+)T cells in the intestines of mice receiving MAP3K2-deficient T cells than in those from mice receiving wild type T cells was observed.Interestingly,under well-defined in vitro differentiation conditions,MAP3K2-deficient naïve T cells were not impaired in their ability to differentiate into Th1,Th17 and Treg.Furthermore,the MAP3K2-regulated colitis severity was mediated by Th1 but not Th17 cells in the intestine.At the molecular level,we showed that MAP3K2-mediated Th1 cell differentiation in the intestine was regulated by IL-18 and required specific JNK activation.Together,our study reveals a novel regulatory role of MAP3K2 in intestinal T cell immunity via the IL-18-MAP3K2-JNK axis and may provide a novel target for intervention in T cell-mediated colitis.

Mild Cytokine Elevation, Moderate CD4^+ T Cell Response and Abundant Antibody Production in Children with COVID-19

Children with Coronavirus Disease 2019(COVID-19) were reported to show milder symptoms and better prognosis than their adult counterparts, but the difference of immune response against SARS-CoV-2 between children and adults hasn’t been reported. Therefore we initiated this study to figure out the features of immune response in children with COVID-19.Sera and whole blood cells from 19 children with COVID-19 during different phases after disease onset were collected.The cytokine concentrations, SARS-CoV-2 S-RBD or N-specific antibodies and T cell immune responses were detected respectively. In children with COVID-19, only 3 of 12 cytokines were increased in acute sera, including interferon(IFN)-cinduced protein 10(IP10), interleukin(IL)-10 and IL-16. We observed an increase in T helper(Th)-2 cells and a suppression in regulatory T cells(Treg) in patients during acute phase, but no significant response was found in the IFN-cproducing or tumor necrosis factor(TNF)-a-producing CD8?T cells in patients. S-RBD and N IgM showed an early induction, while S-RBD and N IgG were prominently induced later in convalescent phase. Potent S-RBD IgA response was observed but N IgA seemed to be inconspicuous. Children with COVID-19 displayed an immunophenotype that is less inflammatory than adults, including unremarkable cytokine elevation, moderate CD4?T cell response and inactive CD8?T cell response, but their humoral immunity against SARS-CoV-2 were as strong as adults. Our finding presented immunological characteristics of children with COVID-19 and might give some clues as to why children develop less severe disease than adults.

HIV-1/AIDS vaccine development： are we in the darkness before the dawn？

The pandemic of human immunodeficiency virus type 1 （HIV-I） has been devastating for the last two decades in a number of developing countries and constituting a grand challenge to the public health. WHO/UNAIDS estimates that approximately 33.2 million people were living with HIV-1 infection by the end of 2007 and almost 2.5 million new infections occurred in 2007. An unprecedented scientific challenge for the AIDS vaccine community is how to develop an effective HIV vaccine that can block HIV transmission and consequently stop the continuing spread of HIV-1. The recent failure of Merck Phase II B trial alerted the HIV vaccine community that new vaccine strategies need to be more exclusively explored. In this review, we outline the basics of HIV vaccine and retrospect the history of the road to HIV vaccine in last two decades, and highlight the challenges we are currently facing and new strategies to develop HIV vaccines in this field.