Tissue-resident memory T cells exhibit phenotypically and functionally heterogeneous in human physiological and pathological nasal mucosa.

Pathogens commonly enter mucosal barrier tissues and tissue-resident memory T cells (TRM) are essential for preventing mucosal lesions. However, the immunological properties of TRM cells in nasal mucosa are poorly known. In comparison with control tissues, decreasing CD103+ TRM cells were observed in Chronic rhinosinusitis with nasal polyps (CRSwNPs) and sinonasal inverted papilloma (SNIP), which presented high capability to produce effector cytokines. In CRSwNPs, we found that CD103+ TRM cells with higher cytokine and Granzyme B coexpressed high PD-1, CD103- TRM cells expressed higher IL-10. Homogenates isolated from CRSwNPs induced CD103 expression on peripheral T cells which could be inhibited by blocking TGF-ß. The frequencies of CD103+ TRM cells in CRSwNPs were extremely negatively correlated with neutrophil infiltration. CD103+ TRM cells from Staphylococcus aureus positive CRSwNPs had a stronger response to SEB. Taken together, two phenotypically and functionally distinct subsets of TRM cells exist in nasal tissues and play critical roles in the progress of CRSwNPs and SNIPs.

Immunogenicity of peptide-based vaccine composed of epitopes from Echinococcus granulosus rEg.P29.

Echinococcus granulosus is one of the main causes of economic loss in the livestock industry because of its food-borne transmission. Cutting off the transmission route is a valid prevention method, and vaccines are the most effective means of controlling and eliminating infectious diseases. However, no human-related vaccine has been yet marketed. As a genetic engineering vaccine, recombinant protein P29 of E. granulosus (rEg.P29) could provide protection against deadly challenges. In this study, we generated peptide vaccines (rEg.P29T , rEg.P29B , and rEg.P29T+B ) based on rEg.P29 and an immunized model was established by subcutaneous immunization. Further evaluation showed that peptide vaccine immunization in mice induced T helper type 1 (Th1)-mediated cellular immune responses, leading to high levels of rEg.P29 or rEg.P29B -specific antibodies. In addition, rEg.P29T+B immunization can induce a higher antibody and cytokine production level than single-epitope vaccines, and immune memory is also longer. Collectively, these results suggest that rEg.P29T+B has the potential to be developed as an efficient subunit vaccine for use in areas where E. granulosus is endemic.

Estrogen enhanced the expression of IL-17 by tissue-resident memory γδT cells from uterus via interferon regulatory factor 4.

Tissue-resident memory γδT cells at mucosal and epithelial sites play an important role for pathogen clearance, immunosurveillance, and participating in physiological processes. Different from other barrier sites, the immune cells in uterus face the protection against infections and tolerate an allogeneic fetus during a successful pregnancy. In the previous study, we found that tissue-resident memory γδT cells were enriched both in human and murine uterus and highly expressed IL-17 that promoted the invasion of trophocytes in vitro. In the current study, we found that γδT cells in uterus but not in blood or spleens expressed higher levels of estrogen receptors. The injection of estrogen into mice increased the proportion of γδT cells in uterus but not in spleens in vivo via CXCR3-CXCL10 chemokine axis. In addition, we found that estrogen enhanced the production of IL-17 but not IFN-γ in vivo and in vitro via interferon regulatory factor 4 but not RORγt and pSTAT3 at mRNA and protein levels. The analysis of cell transcriptome sequence further identified multiple differentially expressed genes between estrogen and control γδT cells. Our study demonstrated that estrogen directly act on γδT cells in uterus to enhance the production of IL-17 that might promote the invasion of trophocytes. Furthermore, our study might provide a new idea that estrogen increased the prevalence of autoimmune diseases in women by enhancing γδT cell-derived IL-17 production in uterus and uncover the critical pathological roles for estrogen in the development of autoimmune diseases.

Clinical characteristics and antibodies against Echinococcus granulosus recombinant antigen P29 in patients with cystic echinococcosis in China.

OBJECTIVES: Cystic echinococcosis (CE) is a neglected parasitic zoonotic disease caused by the larval stage of the tapeworm Echinococcus granulosus (E. granulosus). This study aimed to understand the clinical characteristics of human CE in Ningxia Hui Autonomous Region (NHAR) located in northwest China and to investigate the antibody profiles against the recombinant E. granulosus antigen P29 (rEg.P29) in plasma of CE patients. METHODS: A total of 37 human CE patients, along with 37 healthy donors enrolled in this study and demographic and clinical data were analyzed, including age, gender, laboratory data, symptoms, and cysts description. Plasma levels of cytokines, total IgG, and total IgE were determined by sandwich ELISA kits. Specific antibodies against rEg.P29 and hydatid cyst fluid (HCF) were assessed by indirect ELISA. RESULTS: The results revealed that females have a higher percentage of CE patients than males. The incidence of CE reached a peak in the 41-50 years-old group. The liver was the most frequent location, accounting for 91.9%. Based on the CT images, cysts of 34 patients who had liver involvement, were classified as 1 (2.9%) CE1, 12 (35.3%) CE2, 5 (14.7%) CE3a, 1 (2.9%) CE3b, and 15 (44.2%) CE5. Twenty-nine (78.4%) patients had a single cyst and 8 (21.6%) had at least two cysts. The most frequently reported symptom was upper abdominal pain. The plasma level of IL-6 and total IgE were significantly increased in CE patients compared with healthy donors. Additionally, IgG response to rEg.P29 in CE patients was significantly higher than in healthy donors, and the dominant IgG subclass was IgG4. Further analysis of different patient groups revealed that rEg.P29-specific IgG and IgG4 were only elevated in CE patients with CE2 type cysts. CONCLUSIONS: This study systematically investigated the clinical characteristics of patients with CE and may provide a reference basis for the diagnosis and treatment of CE in NHAR. Furthermore, tests of specific IgG and IgG4 against rEg.P29 can be used as an assisted method for imaging techniques to identify cystic activity and determine the best therapeutic approach for CE.

Baseline T-lymphocyte and cytokine indices in sheep peripheral blood.

BACKGROUND: Sheep are an important livestock species worldwide and an essential large-animal model for animal husbandry and veterinary research. Understanding fundamental immune indicators, especially T-lymphocyte parameters, is necessary for research on sheep diseases and vaccines, to better understand the immune response to bacteria and viruses for reducing the use of antibiotics and improving the welfare of sheep. We randomly selected 36 sheep of similar ages to analyze cell-related immune indicators in peripheral blood mononuclear cells (PBMCs). The proportions of CD4+ and CD8+ T cells in PBMCs were detected by flow cytometry. We used Concanavalin A (Con A) and Phorbol-12-myristate-13-acetate (PMA)/Ionomycin to stimulate PBMCs, and measured the expression of IFN-γ, IL-4, and IL-17A using enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISpot). Simultaneously, PMA/Ionomycin/brefeldin A (BFA) was added to PBMCs, then the expression of IFN-γ, IL-4, and IL-17A was detected by flow cytometry after 4 h of culturing. In addition, we observed the proliferation of PBMCs stimulated with Con A for 3, 4, and 5 days. RESULTS: The proportions of CD4+ T lymphocytes (18.70 ± 4.21%) and CD8+ T lymphocytes (8.70 ± 3.65%) were generally consistent among individuals, with a CD4/CD8 ratio of 2.40 ± 0.79. PBMCs produced high levels of IFN-γ, IL-4, and IL-17A after stimulation with PMA/Ionomycin and Con A. Furthermore, PMA/Ionomycin stimulation of PBMC yielded significantly higher cytokine levels than Con A stimulation. Flow cytometry showed that the level of IFN-γ (51.49 ± 11.54%) in CD8+ T lymphocytes was significantly (p < 0.001) higher than that in CD4+ T lymphocytes (14.29 ± 3.26%); IL-4 (16.13 ± 6.81%) in CD4+ T lymphocytes was significantly (p < 0.001) higher than that in CD8+ T lymphocytes (1.84 ± 1.33%), There was no difference in IL-17A between CD4+ (2.83 ± 0.98%) and CD8+ T lymphocytes (1.34 ± 0.67%). The proliferation of total lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes continued to increase between days 3 and 5; however, there were no significant differences in proliferation between the cell types during the stimulation period. CONCLUSIONS: Evaluating primary sheep immune indicators, especially T lymphocytes, is significant for studying cellular immunity. This study provided valuable data and theoretical support for assessing the immune response of sheep to pathogens and improving sheep welfare.

Identification of a dominant murine T-cell epitope in recombinant protein P29 from Echinococcus granulosus

Echinococcus granulosus causes echinococcosis, an important zoonotic disease worldwide and a major public health issue. Vaccination is an economical and practical approach for controlling E. granulosus. We have previously revealed that a recombinant protein P29 (rEg.P29) is a good vaccine candidate against E. granulosus. However, T cell immunogenic epitopes have not been identified. In the present study, we use rEg.P29-immunized mice as models to screen immunogenic epitopes for the construction of a novel multi-epitope vaccine. We search for immunodominant epitopes from an overlapping peptide library to screen the peptides of rEg.P29. Our results confirm that rEg.P29 immunization in mice elicits the activation of T cells and induces cellular immune responses. Further analyses show that a T cell epitope within amino acids 86­100 of rEg.P29 elicits significant antigen-specific IFN-γ production in CD4+ and CD8+ T cells and promotes specific T-cell activation and proliferation. Collectively, these results provide a reference for the construction of a novel vaccine against broad E. granulosus genotypes based on epitopes of rEg.P29.

The phenotypic and functional study of tissue B cells in respiratory system provided important information for diseases and development of vaccines.

The field of tissue-resident B cells has received increasing attention, yet the feature of tissue B cells in respiratory system is unclear. Here, we first show that non-circulating B cells obtained from nasal, trachea and lung tissues are numerically and phenotypically distinct from their circulating counterparts. Analysis of single cell transcriptome sequence identified multiple differentially expressed genes between non-circulating B cells and circulating B cells, which illustrated their heterogeneity. Furthermore, we found high expression of CXCR3 on non-circulating B cells, and the chemokine CXCL11 was also up-regulated in the respiratory tissues, suggesting that CXCR3-CXCL11 axis might accelerate the local resident of non-circulating B cells in respiratory tract. Interestingly, intranasal immunization with BCG in mice elicited a sustained humoral immune response via induction of IgA and IgG Abs, which revealed the role of B cells. Meanwhile, tissue-resident B cells, IgA+ and IgG+ memory B cells (MBCs) in respiratory tissues, as well as plasma cells in bone marrow, were expanded and maintained, and these subsets probably developed into antibody-producing cells to participate in the local humoral immunity. Our data illustrate the phenotype and function of tissue B cells in the upper and lower airways, provide references for the prospective development of vaccines.

Local IL-17 positive T cells are functionally associated with neutrophil infiltration and their development is regulated by mucosal microenvironment in nasal polyps.

OBJECTIVE AND DESIGN: IL-17 plays essential roles in neutrophilic inflammation in the lower respiratory tract, however, the characteristics of local IL-17+ T cells in nasal inflammatory mucosa are not fully understood. We investigated the roles of IL-17+ T cells in regulating neutrophil infiltration and the effect of the mucosal microenvironment in modulating IL-17+ T cell differentiation in CRSwNP tissues. SUBJECTS: 47 polyp tissues from chronic rhinosinusitis with nasal polyps (CRSwNP) patients without corticosteroid therapy and 26 tissues from healthy mucosa were obtained. METHODS: Immunohistochemistry and flow cytometry were used to analyze the neutrophil infiltration, local IL-17+ T cell subsets, as well as cytokine producing profiles of IL-17+ T cell; tissue homogenates were used to study neutrophil migration and IL-17+ T cell differentiation. RESULTS: Increase of IL-17+ cells and IL-17+ T cell subsets was significant in polyp tissues versus controls, IL-17+ cell number was positively correlated with neutrophil infiltration; while homogenates from polyp tissues with high IL-17 promoted neutrophil migration in vitro. IL-17 response was found in polyp-derived T cells upon Staphylococcus aureus infection. IL-17+ T cells were also down-regulated in polyps from patients treated with glucocorticoid steroids, and exhibited poly-functionality patterns in polyp tissues. Finally, IL-17+ T cell differentiation could be induced by IL-23, and homogenates from polyps could enhance IL-17+ T cell development. CONCLUSIONS: This study determined a functional association of IL-17+ T cells with neutrophils in CRSwNP, and revealed that polyp microenvironment could promote IL-17+ T cell differentiation, suggesting a potential feedback role for IL-17+ T cell development and local neutrophilic inflammation.

Amphiregulin alleviated concanavalin A-induced acute liver injury via IL-22.

OBJECTIVES: Amphiregulin (Areg), a glycoprotein from the epidermal growth factor receptor (EGFR) ligand family, has a well-documented protective role against tissue injury; however, its effects on immune-mediated liver injury are still unclear. Here, we used a concanavalin A (ConA)-induced acute liver hepatitis model to explore the effects of Areg on immune-mediated acute liver injury. MATERIALS AND METHODS: Some C57BL/6 mice were administered ConA at a dose of 20 mg/kg (model mice), and some received 5 µg of Areg (treated mice). Then, their survival rates over 36 h were analyzed. After 5 h of treatment, liver function, hepatic histology, and apoptosis in liver tissue were investigated, and cytokine expression and neutrophil infiltration and activity in the liver were detected. Moreover, the protective effects of Areg were also evaluated without IL-22 in vivo. RESULTS: Our results showed that Areg administration increased acute liver failure (ALF) mouse survival, restored liver function, and alleviated liver damage. Interestingly, Areg administration increased IL-22 production in hepatic T cells and upregulated IL-22 concentrations in the serum and liver, whereas IL-22 neutralization completely abolished the therapeutic effect of Areg. Meanwhile, Areg administration was concomitant with increased expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, which are important in the hepatoprotective mechanism of IL-22. CONCLUSIONS: Areg showed direct protective effects against ConA-induced acute liver injury, which suggests the potential therapeutic application of Areg in immune-mediated ALF.

Intranasal immunization with Mycobacterium tuberculosis Rv3615c induces sustained adaptive CD4+ T-cell and antibody responses in the respiratory tract.

Sustained adaptive immunity to pathogens provides effective protection against infections, and effector cells located at the site of infection ensure rapid response to the challenge. Both are essential for the success of vaccine development. To explore new vaccination approach against Mycobacterium tuberculosis (M.tb) infection, we have shown that Rv3615c, identified as ESX-1 substrate protein C of M.tb but not expressed in BCG, induced a dominant Th1-type response of CD4+ T cells from patients with tuberculosis pleurisy, which suggests a potential candidate for vaccine development. But subcutaneous immunization with Rv3615c induced modest T-cell responses systemically, and showed suboptimal protection against virulent M.tb challenge at the site of infection. Here, we use a mouse model to demonstrate that intranasal immunization with Rv3615c induces sustained capability of adaptive CD4+ T- and B-cell responses in lung parenchyma and airway. Rv3615c contains a dominant epitope of mouse CD4+ T cells, Rv3615c41-50 , and elicits CD4+ T-cell response with an effector-memory phenotype and multi-Th1-type cytokine coexpressions. Since T cells resident at mucosal tissue are potent at control of infection at early stage, our data show that intranasal immunization with Rv3615c promotes a sustained regional immunity to M.tb, and suggests a potency in control of M.tb infection. Our study warranties a further investigation of Rv3615c as a candidate for development of effective vaccination against M.tb infection.

Circulating pig-specific DNA as a novel biomarker for monitoring xenograft rejection.

Monitoring for immune rejection is crucial for long-term survival of pig xenografts. Circulating DNA is a promising non-invasive biomarker for either organ injury or response to therapy. In this study, circulating pig-specific DNA (cpsDNA) was monitored during xenograft rejection. Potential targets of cpsDNA were selected by in silico analysis, and species specificity of selected primers was confirmed by PCR. Subsequently, cpsDNA as a biomarker was evaluated using a complement-dependent cytotoxicity (CDC) assay in vitro. Then, early diagnosis and response to rapamycin were assessed by an in vivo imaging model of pig-to-mouse cell transplantation. Finally, cpsDNA was monitored in a pig-to-monkey artery patch transplantation model. The results showed that (a) a method of cpsDNA quantitation was established for application in mouse and nonhuman primate models; (b) cpsDNA reflected CDC in vitro; (c) cpsDNA in vivo mirrored xenograft rejection, and correlated with xenograft loss in pig-to-mouse cell transplantation; (d) cpsDNA was significantly reduced when rapamycin was administered; and (e) dynamic cpsDNA was detectable in pig-to-monkey artery patch transplantation. In conclusion, measurement of cpsDNA could prove to be a less invasive, but more specific and sensitive low-cost biomarker enabling monitoring of xenograft rejection and the response to immunosuppressive therapy.

A Novel Hypothesis on Excessive Activation of Residual B Lymphocytes in Common Variable Immunodeficiency Concurrent with Aseptic, Erosive Polyarthritis.

The aim of this study was to report aseptic, erosive polyarthritis in a patient with common variable immunodeficiency (CVID), which is quite different from the vastly more common nonerosive form. Peripheral blood mononuclear cells of the patient were isolated. Flow cytometry was used to analyze the proportion and function of lymphocytes. A Parker-Pearson needle biopsy was performed on the right knee. Four of her unaffected family members were enrolled as controls. A 21-year-old woman was admitted for recurrent polyarthritis of 3-year duration. The right knee, hip, wrist, proximal interphalangeal joints, and left elbow were involved, with progressive joint destruction. She was diagnosed as having CVID based on her recurrent infections, poor response to vaccines, and marked hypogammaglobulinemia. No bacterium or mycobacterium was detected in synovium or synovial fluid. The synovium was infiltrated by lymphocytes rather than neutrophils. Polyarthritis did not resolve by adequate intravenous immunoglobulin substitution and empirical antibiotic treatment, but resolved gradually after treatment with methylprednisolone and tacrolimus, supporting the diagnosis of aseptic polyarthritis. Further analyses showed that although only 0.5% of residual B lymphocytes were existent in peripheral blood of the patient, expressions of activation marker CD69 and production of IL-1ß, IL-6, and TNF-α were high. Marked infiltration with CD19+B lymphocytes (as well as CD4+ or CD8+ T lymphocytes) was detected in the synovium. The proportion of IL21+CD4+Th cells from peripheral blood of the patient was high. CD4+ Th cells from the patient secreted nearly 3 times more IL-21 than the same cell type analyzed from unaffected family members, perhaps due to excessive compensation to assist the function of residual B lymphocytes. A novel hypothesis in CVID concurrent with aseptic, erosive polyarthritis is that excessive activation of residual B lymphocytes infiltrate into the synovium of the involved joints and lead to polyarthritis and joint destruction.

Detection of IL-9 producing T cells in the PBMCs of allergic asthmatic patients.

BACKGROUND: Interleukin-9 (IL-9) was reported as an active participant in the pathogenesis of allergic asthma. This study aimed to investigate the major source ofIL-9 and its effect on interferon γ (IFN-γ) and immunoglobulin (Ig) secretion by B cells. METHODS: We isolated peripheral blood mononuclear cells from children with allergic asthma and healthy children. IL-9, IL-4 and IFN-γ expression were detected by ELISA, ELISpot and Flowcytometry. Expression of transcription factor PU.1 was measured by Western Blot. We evaluated the effect of IL-9 on B cell activation and Ig production. RESULTS: Results showed that compared with healthy children, levels of IL-9, IL-4 and PU.1 were elevated and levels of IFN-γ were lower in children with allergic asthma. IL-9-expressing CD4+ T cells did not co-express IL-4. Exogenous IL-9 inhibited IFN-γ production in a dose-dependent manner. Antigen-specific Th9 cells existed in children with house dust mite allergic asthma. IL-9 up-regulated expression of CD69 and CD25 on B cells and combination of IL-9 and IL-4 enhanced IgE production. CONCLUSIONS: In conclusion, our results showed that Th9 cells may be the major source of IL-9 in children with allergic asthma. In these patients, IL-9 impairs IFN-γ production and synergistically promotes IL-4-induced IgE secretion.

The ligands of translocator protein inhibit human Th1 responses and the rejection of murine skin allografts.

The translocator protein (TSPO) ligands affected inflammatory and immune responses. However, the exact effects of TSPO ligands on Th1 responses in vitro and in vivo are still unclear. In the present study, we found that TSPO ligands, FGIN1-27 and Ro5-4864, suppressed the cytokine production in a dose-dependent manner by purified human CD4+ T-cells from peripheral blood mononuclear cells (PBMCs) after stimulation. TSPO ligands inhibited the production of interferon γ (IFN-γ) by memory CD4+ T-cells and the differentiation of naïve CD4+ T-cells into Th1 cells via suppressing the activity of the corresponding transcription factors as indicated by reduced expression of T-bet and down-regulation of STAT1, STAT4 and STAT5 phosphorylation. TSPO ligands suppressed cell proliferation and activation of CD4+ T-cells by the inhibition of TCR signal transduction including membrane proteins: Zap, Lck, Src; cytoplasm proteins: Plcγ1, Slp-76, ERK, JNK and the nucleoproteins: c-Jun and c-Fos. In addition, FGIN1-27 inhibited mixed lymphocyte reactions by human or murine cells. After the transplantation of allogeneic murine skin, injection of FGIN1-27 into mice prevented graft rejection by inhibition of cell infiltration and IFN-γ production. Taken together, our data suggest that TSPO ligands inhibit Th1 cell responses and might be novel therapeutic medicine for the treatment of autoimmune diseases and prevention of transplant rejection.

Mycobacterium tuberculosis Rv3615c is a highly immunodominant antigen and specifically induces potent Th1-type immune responses in tuberculosis pleurisy.

T-cell responses have been demonstrated to be essential for preventing Mycobacterium tuberculosis infection. The Th1-cytokines produced by T cells, such as INF-γ, IL-2, and TNF-α, not only limit the invasion of M. tuberculosis but also eliminate the pathogen at the site of infection. Bacillus Calmette-Guérin (BCG) is known to induce Th1-type responses but the protection is inadequate. Identification of immunogenic components, in addition to those expressed in BCG, and induction of a broad spectrum of Th1-type responses provide options for generating sufficient adaptive immunity. Here, we studied human pulmonary T-cell responses induced by the M. tuberculosis-specific antigen Rv3615c, a protein with a similar size and sequence homology to ESAT-6 and CFP-10, which induced dominant CD4+ T-cell responses in human tuberculosis (TB) models. We characterized T-cell responses including cytokine profiling, kinetics of activation, expansion, differentiation, TCR usage, and signaling of activation induced by Rv3615c compared with other M. tuberculosis-specific antigens. The expanded CD4+ T cells induced by Rv3615c predominately produced Th1, but less Th2 and Th17, cytokines and displayed effector/memory phenotypes (CD45RO+CD27-CD127-CCR7-). The magnitude of expansion and cytokine production was comparable to those induced by well-characterized the 6 kDa early secreted antigenic target (ESAT-6), the 10 kDa culture filtrate protein (CFP-10) and BCG. Rv3615c contained multiple epitopes Rv3615c1-15, Rv3615c6-20, Rv3615c66-80, Rv3615c71-85 and Rv3615c76-90 that activated CD4+ T cells. The Rv3615c-specific CD4+ T cells shared biased of T-cell receptor variable region of ß chain (TCR Vß) 1, 2, 4, 5.1, 7.1, 7.2 and/or 22 chains to promote their differentiation and proliferation respectively, by triggering a signaling cascade. Our data suggest that Rv3615c is a major target of Th1-type responses and can be a highly immunodominant antigen specific for M. tuberculosis infection.

Exacerbation of oxygen-glucose deprivation-induced blood-brain barrier disruption: potential pathogenic role of interleukin-9 in ischemic stroke.

Interleukin (IL)-9 exerts a variety of functions in autoimmune diseases. However, its role in ischemic brain injury remains unknown. The present study explored the biological effects of IL-9 in ischemic stroke (IS). We recruited 42 patients newly diagnosed with IS and 22 age- and sex-matched healthy controls. The expression levels of IL-9 and percentages of IL-9-producing T cells, including CD3+CD4+IL-9+ and CD3+CD8+IL-9+ cells, were determined in peripheral blood mononuclear cells (PBMCs) obtained from patients and control individuals. We also investigated the effects of IL-9 on the blood-brain barrier (BBB) following oxygen-glucose deprivation (OGD) and the potential downstream signaling pathways. We found that patients with IS had higher IL-9 expression levels and increased percentages of IL-9-producing T cells in their PBMCs. The percentages of CD3+CD4+IL-9+ and CD3+CD8+IL-9+ T cells were positively correlated with the severity of illness. In in vitro experiments using bEnd.3 cells, exogenously administered IL-9 exacerbated the loss of tight junction proteins (TJPs) in cells subjected to OGD plus reoxygenation (RO). This effect was mediated via activation of IL-9 receptors, which increased the level of endothelial nitric oxide synthase (eNOS), as well as through up-regulated phosphorylation of signal transducer and activator of transcription 1 and 3 and down-regulated phosphorylated protein kinase B/phosphorylated phosphatidylinositol 3-kinase signaling. These results indicate that IL-9 has a destructive effect on the BBB following OGD, at least in part by inducing eNOS production, and raise the possibility of targetting IL-9 for therapeutic intervention in IS.

Characteristics of Schistosoma japonicum infection induced IFN-γ and IL-4 co-expressing plasticity Th cells.

Schistosoma japonicum infection can induce granulomatous inflammation and cause tissue damage in the mouse liver. The cytokine secretion profile of T helper (Th) cells depends on both the nature of the activating stimulus and the local microenvironment (e.g. cytokines and other soluble factors). In the present study, we found an accumulation of large numbers of IFN-γ(+)  IL-4(+)  CD4(+) T cells in mouse livers. This IFN-γ(+)  IL-4(+) cell population increased from 0·68 ± 0·57% in uninfected mice to 7·05 ± 3·0% by week 4 following infection and to 9·6 ± 5·28% by week 6, before decreasing to 6·3 ± 5·9% by week 8 in CD4 T cells. Moreover, IFN-γ(+)  IL-4(+) Th cells were also found in mouse spleen and mesenteric lymph nodes 6 weeks after infection. The majority of the IFN-γ(+)  IL-4(+) Th cells were thought to be related to a state of immune activation, and some were memory T cells. Moreover, we found that these S. japonicum infection-induced IFN-γ(+)  IL-4(+) cells could express interleukin-2 (IL-2), IL-9, IL-17 and high IL-10 levels at 6 weeks after S. japonicum infection. Taken together, our data suggest the existence of a population of IFN-γ(+)  IL-4(+) plasticity effector/memory Th cells following S. japonicum infection in C57BL/6 mice.

Circulating Organ-Specific MicroRNAs Serve as Biomarkers in Organ-Specific Diseases: Implications for Organ Allo- and Xeno-Transplantation.

Different cell types possess different miRNA expression profiles, and cell/tissue/organ-specific miRNAs (or profiles) indicate different diseases. Circulating miRNA is either actively secreted by living cells or passively released during cell death. Circulating cell/tissue/organ-specific miRNA may serve as a non-invasive biomarker for allo- or xeno-transplantation to monitor organ survival and immune rejection. In this review, we summarize the proof of concept that circulating organ-specific miRNAs serve as non-invasive biomarkers for a wide spectrum of clinical organ-specific manifestations such as liver-related disease, heart-related disease, kidney-related disease, and lung-related disease. Furthermore, we summarize how circulating organ-specific miRNAs may have advantages over conventional methods for monitoring immune rejection in organ transplantation. Finally, we discuss the implications and challenges of applying miRNA to monitor organ survival and immune rejection in allo- or xeno-transplantation.

Human memory, but not naive, CD4+ T cells expressing transcription factor T-bet might drive rapid cytokine production.

We found that after stimulation for a few hours, memory but not naive CD4(+) T cells produced a large amount of IFN-γ; however, the mechanism of rapid response of memory CD4(+) T cells remains undefined. We compared the expression of transcription factors in resting or activated naive and memory CD4(+) T cells and found that T-bet, but not pSTAT-1 or pSTAT-4, was highly expressed in resting memory CD4(+) T cells and that phenotypic characteristics of T-bet(+)CD4(+) T cells were CD45RA(low)CD62L(low) CCR7(low). After short-term stimulation, purified memory CD4(+) T cells rapidly produced effector cytokines that were closely associated with the pre-existence of T-bet. By contrast, resting naive CD4(+) T cells did not express T-bet, and they produced cytokines only after sustained stimulation. Our further studies indicated that T-bet was expressed in the nuclei of resting memory CD4(+) T cells, which might have important implications for rapid IFN-γ production. Our results indicate that the pre-existence and nuclear mobilization of T-bet in resting memory CD4(+) T cells might be a possible transcriptional mechanism for rapid production of cytokines by human memory CD4(+) T cells.

A novel common gamma chain mutation in a Chinese family with X-linked severe combined immunodeficiency (X-SCID; T(-)NK(-)B(+)).

X-linked severe combined immunodeficiency (X-SCID) is one of the most common causes of primary immunodeficiencies in humans. A 4-month-old boy with recurrent pulmonary infection had decreased numbers of CD3(+), CD4(+), CD8(+) T lymphocytes, and NK cells and increased levels of CD19(+) B cells but no memory B cells or plasma cells. The production of cytokines by T cells and the activation of T and B cells were either absent or inefficient. While B cell levels were high, they were all IgM-positive, and the secretion of all Ig isotypes by activated B cells in vitro was defective. Genomic DNA sequencing revealed that the patient had missense mutations in the IL2RG (exon 5, 718 T > C) and IL7R genes (exon 2, 197 T > C; exon 4, 412G > A). Although the patient's father and one of his sisters have the same missense homozygous mutations of the IL7R gene, neither of them exhibited the immunological phenotype of SCID. The results indicate that the IL2RG gene mutation or a combination of the IL7R and IL2RG mutations in the sick boy had resulted in T(-)NK(-)B(+) SCID.