Immunological characteristics of CD103+CD161+ T lymphocytes on chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNPs) is a heterogeneous disease characterized by local inflammation of the upper airway and sinus mucosa. T cell-mediated immune responses play irreplaceable roles in the pathogenesis of nasal polyps. CD161+ T cells have been implicated in the pathology of several diseases through cytokine production and cytotoxic activity. However, the immunological characteristics of CD161+ T cells in nasal mucosa are still not well understood, particularly in CRSwNPs. Our research revealed a notable enrichment of CD161+ T cells in nasal tissues compared to peripheral blood, with a significantly more infiltration of CD161+ T cells in CRSwNPs compared to control nasal samples. Phenotypical analysis found that CD161+ T cells predominantly co-expressed tissue-resident memory surface markers CD103, CD69, and CD45RO. CD161+CD103+ T cells demonstrated complicated effector functions, marked by elevated levels of PD-1, CTLA-4, IL-17, and IFN-γ and diminished expression of FoxP3 and CD25. Interestingly, despite CD161+ T cells was more abundant in polyp tissues compared to normal control tissues, and then further categorizing polyp samples into distinct groups based on clinical characteristics, only the recurrent CRSwNP group showed a significant reduction in CD161+CD8+ T cells compared to the primary CRSwNP group. This finding suggested the necessity for further research to comprehensively understand the underlying mechanisms and the broader significance of CD161+ T cells in the advancement and relapse of CRSwNPs.

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.

A senescence-based prognostic gene signature for colorectal cancer and identification of the role of SPP1-positive macrophages in tumor senescence.

Background: Senescence is significantly associated with cancer prognosis. This study aimed to construct a senescence-related prognostic model for colorectal cancer (CRC) and to investigate the influence of senescence on the tumor microenvironment. Methods: Transcriptome and clinical data of CRC cases were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Senescence-related prognostic genes detected by univariate Cox regression were included in Least Absolute Shrinkage and Selection Operator (LASSO) analysis to construct a model. The efficacy of the model was validated using the receiver operating characteristic (ROC) curve and survival analysis. Differentially expressed genes (DEGs) were identified and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed. CIBERSORT and Immuno-Oncology Biological Research (IOBR) were used to investigate the features of the tumor microenvironment. Single-cell RNA-seq data were used to investigate the expression levels of model genes in various cell types. Immunofluorescence staining for p21, SPP1, and CD68 was performed with human colon tissues. Results: A seven-gene (PTGER2, FGF2, IGFBP3, ANGPTL4, DKK1, WNT16 and SPP1) model was finally constructed. Patients were classified as high- or low-risk using the median score as the threshold. The area under the ROC curve (AUC) for the 1-, 2-, and 3-year disease-specific survival (DSS) were 0.731, 0.651, and 0.643, respectively. Survival analysis showed a better 5-year DSS in low-risk patients in the construction and validation cohorts. GO and KEGG analyses revealed that DEGs were enriched in extracellular matrix (ECM)-receptor interactions, focal adhesion, and protein digestion and absorption. CIBERSORT and IOBR analyses revealed an abundance of macrophages and an immunosuppressive environment in the high-risk subgroup. Low-risk patients had higher response rates to immunotherapy than high-risk patients. ScRNA-seq data revealed high expression of SPP1 in a subset of macrophages with strong senescence-associated secretory phenotype (SASP) features. Using CRC tumor tissues, we discovered that SPP1+ macrophages were surrounded by a large number of senescent tumor cells in high-grade tumors. Conclusion: Our study presents a novel model based on senescence-related genes that can identify CRC patients with a poor prognosis and an immunosuppressive tumor microenvironment. SPP1+ macrophages may correlate with cell senescence leading to poor prognosis.

Single-cell and spatial transcriptome analyses revealed cell heterogeneity and immune environment alternations in metastatic axillary lymph nodes in breast cancer.

BACKGROUND: Tumor heterogeneity plays essential roles in developing cancer therapies, including therapies for breast cancer (BC). In addition, it is also very important to understand the relationships between tumor microenvironments and the systematic immune environment. METHODS: Here, we performed single-cell, VDJ sequencing and spatial transcriptome analyses on tumor and adjacent normal tissue as well as axillar lymph nodes (LNs) and peripheral blood mononuclear cells (PBMCs) from 8 BC patients. RESULTS: We found that myeloid cells exhibited environment-dependent plasticity, where a group of macrophages with both M1 and M2 signatures possessed high tumor specificity spatially and was associated with worse patient survival. Cytotoxic T cells in tumor sites evolved in a separate path from those in the circulatory system. T cell receptor (TCR) repertoires in metastatic LNs showed significant higher consistency with TCRs in tumor than those in nonmetastatic LNs and PBMCs, suggesting the existence of common neo-antigens across metastatic LNs and primary tumor cites. In addition, the immune environment in metastatic LNs had transformed into a tumor-like status, where pro-inflammatory macrophages and exhausted T cells were upregulated, accompanied by a decrease in B cells and neutrophils. Finally, cell interactions showed that cancer-associated fibroblasts (CAFs) contributed most to shaping the immune-suppressive microenvironment, while CD8+ cells were the most signal-responsive cells. CONCLUSIONS: This study revealed the cell structures of both micro- and macroenvironments, revealed how different cells diverged in related contexts as well as their prognostic capacities, and displayed a landscape of cell interactions with spatial information.

iNOS is essential to maintain a protective Th1/Th2 response and the production of cytokines/chemokines against Schistosoma japonicum infection in rats.

Humans and a wide range of mammals are generally susceptible to Schistosoma infection, while some rodents such as Rattus rats and Microtus spp are not. We previously demonstrated that inherent high expression levels of nitric oxide (NO), produced by inducible nitric oxide synthase (iNOS), plays an important role in blocking the growth and development of Schistosoma japonicum in wild-type rats. However, the potential regulatory effects of NO on the immune system and immune response to S. japonicum infection in rats are still unknown. In this study, we used iNOS-knockout (KO) rats to determine the role of iNOS-derived NO in the immune system and immunopathological responses to S. japonicum infection in rats. Our data showed that iNOS deficiency led to weakened immune activity against S. japonicum infection. This was characterized by the impaired T cell responses and a significant decrease in S. japonicum-elicited Th2/Th1 responses and cytokine and chemokine-producing capability in the infected iNOS-KO rats. Unlike iNOS-KO mice, Th1-associated cytokines were also decreased in the absence of iNOS in rats. In addition, a profile of pro-inflammatory and pro-fibrogenic cytokines was detected in serum associated with iNOS deficiency. The alterations in immune responses and cytokine patterns were correlated with a slower clearance of parasites, exacerbated granuloma formation, and fibrosis following S. japonicum infection in iNOS-KO rats. Furthermore, we have provided direct evidence that high levels of NO in rats can promote the development of pulmonary fibrosis induced by egg antigens of S. japonicum, but not inflammation, which was negatively correlated with the expression of TGF-ß3. These studies are the first description of the immunological and pathological profiles in iNOS-KO rats infected with S. japonicum and demonstrate key differences between the responses found in mice. Our results significantly enhance our understanding of the immunoregulatory effects of NO on defensive and immunopathological responses in rats and the broader nature of resistance to pathogens such as S. japonicum.

Innate Resistance to Leishmania amazonensis Infection in Rat Is Dependent on NOS2.

Leishmania infection causes diverse clinical manifestations in humans. The disease outcome is complicated by the combination of many host and parasite factors. Inbred mouse strains vary in resistance to Leishmania major but are highly susceptible to Leishmania amazonensis infection. However, rats are highly resistant to L. amazonensis infection due to unknown mechanisms. We use the inducible nitric oxide synthase (Nos2) gene knockout rat model (Nos2 -/- rat) to investigate the role of NOS2 against leishmania infection in rats. Our results demonstrated that diversion toward the NOS2 pathway is the key factor explaining the resistance of rats against L. amazonensis infection. Rats deficient in NOS2 are susceptible to L. amazonensis infection even though their immune response to infection is still strong. Moreover, adoptive transfer of NOS2 competent macrophages into Nos2 -/- rats significantly reduced disease development and parasite load. Thus, we conclude that the distinct L-arginine metabolism, observed in rat macrophages, is the basis of the strong innate resistance to Leishmania. These data highlight that macrophages from different hosts possess distinctive properties and produce different outcomes in innate immunity to Leishmania infections.

Tissue-Resident Memory-Like CD8+ T Cells Exhibit Heterogeneous Characteristics in Tuberculous Pleural Effusion.

Tissue-resident memory T (TRM) cells are well known to play critical roles in peripheral tissues during virus infection and tumor immunology. Our previous studies indicated that CD69+CD4+ and CD69+CD8+ T cells in tuberculous pleural effusion (TPE) were antigen-specific memory T cells. However, the phenotypical and functional characteristics of CD8+ TRM cells in tuberculosis remain unknown. We found that CD103+CD8+ T cells were the predominant subset of CD103+ lymphocytes in TPE; both CD103 and CD69 expressed on memory CD8+ T cells from TPE were significantly increased compared with those from paired peripheral blood. Phenotypically, CD103+CD69+ and CD103+CD69-CD8+ T cells expressed higher levels of CD45RO than CD103-CD69+CD8+ T cells did; CD103+CD69-CD8+ T cells highly expressed CD27, CD127, and CD62L and some chemokine receptors. We further compared the functional differences among the four distinct CD45RO+CD8+ T subsets identified by CD103 and CD69 expression. In consist with our published results, CD69+CD8+ T cells, but not CD103+CD8+, produced high levels of IFN-γ after treatment with BCG in the presence of BFA. Nevertheless, CD103-CD69+ and CD103+CD69+ memory CD8+ T cells expressed higher levels of Granzyme B, while CD103+CD69- memory CD8+ T cells were characterized as a possibly immunosuppressive subset by highly expressing CTLA-4, CD25, and FoxP3. Furthermore, TGF-ß extremely increased CD103 expression but not CD69 in vitro. Together, CD103+CD8+ T cells form the predominant subset of CD103+ lymphocytes in TPE; CD103 and CD69 expression defines distinct CD8+ TRM-like subsets exhibiting phenotypical and functional heterogeneity. Our findings provide an important theoretical basis to optimize and evaluate new tuberculosis vaccines.

HNRNPD interacts with ZHX2 regulating the vasculogenic mimicry formation of glioma cells via linc00707/miR-651-3p/SP2 axis.

Studies have found that RNA-binding proteins (RBPs) are dysfunctional and play a significant regulatory role in the development of glioma. Based on The Cancer Genome Atlas database and the previous studies, we selected heterogeneous nuclear ribonucleoprotein (HNRNPD) as the research candidate and sought its downstream targeted genes. In the present study, HNRNPD, linc00707, and specific protein 2 (SP2) were highly expressed, while zinc fingers and homeboxes 2 (ZHX2) and miR-651-3p were remarkedly downregulated in glioma tissues and cells. HNRNPD, linc00707, and SP2 knockdown or ZHX2 and miR-651-3p overexpression suppressed glioma cells proliferation, migration, and invasion and vasculogenic mimicry (VM) formation. Knockdown of HNRNPD increased the stability of ZHX2 mRNA. ZHX2 bound to the promoter region of linc00707 and negatively regulate its expression. Linc00707 could bind with miR-651-3p, while miR-651-3p bound to the 3' untranslated region (3'UTR) of SP2 mRNA to negatively regulate its expression. The transcription factor SP2 directly bound to the promoter regions of the VM formation-related proteins MMP2, MMP9, and VE-cadherin, playing a role in promoting transcription in order to regulate the VM formation ability of glioma cells.

Single-cell transcriptome analysis revealed the heterogeneity and microenvironment of gastrointestinal stromal tumors.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract. In this study, we performed single-cell RNA sequencing (RNA-seq) on intra- and peri-tumor tissues from GIST patients with the aim of discovering the heterogeneity of tumor cells in GIST and their interactions with other cells. We found four predominating cell types in GIST tumor tissue, including T cells, macrophages, tumor cells, and NK cells. Tumor cells could be clustered into two groups: one was highly proliferating and associated with high risk of metastasis, the other seemed "resting" and associated with low risk. Their clinical relevance and prognostic values were confirmed by RNA-seq of 65 GIST samples. T cells were the largest cell type in our single-cell data. Two groups of CD8+ effector memory (EM) cells were in the highest clonal expansion and performed the highest cytotoxicity but were also the most exhausted among all T cells. A group of macrophages were found polarized to possess both M1 and M2 signatures, and increased along with tumor progression. Cell-to-cell interaction analysis revealed that adipose endothelial cells had high interactions with tumor cells to facilitate their progression. Macrophages were at the center of the tumor microenvironment, recruiting immune cells to the tumor site and having most interactions with both tumor and nontumor cells. In conclusion, we obtained an overview of the GIST microenvironment and revealed the heterogeneity of each cell type and their relevance to risk classifications, which provided a novel theoretical basis for learning and curing GISTs.

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.

High-dose vitamin C alleviates pancreatic injury via the NRF2/NQO1/HO-1 pathway in a rat model of severe acute pancreatitis.

BACKGROUND: Oxidative stress plays a pivotal role in the progress of severe acute pancreatitis (SAP). Vitamin C (VC) is the most important antioxidant in plasma. However, the effects of an intravenous administration of high-dose VC and the mechanisms by which it exerts its antioxidant function in an experimental model of SAP have not been determined. METHODS: Sodium taurocholate was used to induce rat pancreatic injury and AR42J cells injury. After the establishment of SAP model, SAP rat and injured AR42J cells were treated with VC. For the injured AR42J cells, small interfering RNA-mediated knockdown of NRF2 was conducted after VC treatment. The histopathological characteristics, the apoptosis of pancreatic acinar cells, oxidative stress markers and levels of enzymes, biochemical indicators, and inflammatory cytokines were examined in vivo and in vitro. Furthermore, the mortality of rats was assessed. RESULTS: In vivo and in vitro results demonstrated that VC treatment ameliorated apoptosis of pancreatic acinar cells, as evidenced by the increase in Bcl-2, Bcl-XL, and MCL-1 expressions and decrease in Bax and cleaved caspase-3 expression along with decreased TUNEL-positive cells. Also, we found that the elevation of MDA and decrease of SOD, GPx, GSH/GSSG, and T-AOC induced by SAP were reversed by VC treatment in vivo and in vitro, and VC treatment increased expressions of Nrf2, NQO1, and HO-1 in SAP model at protein and gene level, indicating that VC attenuated oxidative stress via the NRF2/NQO1/HO-1 pathway. Meanwhile, it was found that sodium taurocholate significantly induced the release of amylase, lipase, IL-1ß, and IL-6 in rat plasma and AR42J cells, which were declined by VC treatment. In vitro results also revealed that these alterations in sodium taurocholate-injured AR42J cells due to VC treatment was attenuated by NRF2 knockdown. In addition, VC at a dose of 500 mg/kg decreased the levels of lactic acid, Cre, NGAL, AST, and ALT in the plasma of SAP rats, suggesting the improvement of renal and pancreatic injury and liver function of SAP rats. Furthermore, the mortality of SAP rats was 50%, which declined to 30% after VC treatment. CONCLUSIONS: The present study suggests that high-dose of VC ameliorate pancreatic injury of SAP via the NRF2/NQO1/HO-1 pathway to inhibit oxidative stress.

A Novel RAG1 Mutation in a Compound Heterozygous Status in a Child With Omenn Syndrome.

Omenn syndrome is a rare autosomal recessive disorder characterized by severe, combined immunodeficiency and autoimmune features. In this case study, we found Omenn syndrome in a 3-month-old boy with recurrent infection, erythroderma, axillary lymphadenopathy, and hepatosplenomegaly. The numbers of eosinophile granulocytes and the levels of immunoglobulin E in his blood were distinctly elevated. Circulating B cells were absent, and the numbers of activated T lymphocytes were present in his peripheral blood. The production of T cell cytokines was significantly higher in the patient compared to the control samples except for interferon gamma. Whole exome sequencing revealed that the patient carried compound heterozygous mutations in the RAG1 gene, which included a previously undescribed frameshift mutation (exon 2, 2491_2497del, p. K830fsX4) and a missense mutation (exon 2, 2923 C > T, p.R975W).

MLN4924 Exerts a Neuroprotective Effect against Oxidative Stress via Sirt1 in Spinal Cord Ischemia-Reperfusion Injury.

Oxidative stress is a leading contributor to spinal cord ischemia-reperfusion (SCIR) injury. Recently, MLN4924, a potent and selective inhibitor of the NEDD8-activating enzyme, was shown to exert a neuroprotective effect against oxidative stress in vitro. However, it is unknown whether MLN4924 plays a protective role against SCIR injury. In the present study, we found that MLN4924 treatment significantly attenuated oxidative stress and neuronal cell death induced by H2O2 in SH-SY-5Y neural cells and during rat SCIR injury. Furthermore, MLN4924 administration restored neurological and motor functions in rats with SCIR injury. Mechanistically, we found that MLN4924 protects against H2O2- and SCIR injury-induced neurodegeneration by regulating sirtuin 1 (Sirt1) expression. Collectively, these findings demonstrate the neuroprotective role of MLN4924 against oxidative stress in SCIR injury via Sirt1.

Poly-functional T helper cells in human tonsillar mononuclear cells.

Tonsils are important lymphoid organs in which B cells and T cells complete their maturation and identify cells that are infected by pathogens. However, the functions of T cells in human tonsils remain unclear, especially the characteristics of polyfunctional CD4+ T helper cells. In this study, we used multi-color flow cytometry to analyze the expression or co-expression of effector cytokines in CD4+ T cells from tonsillar tissues. We have demonstrated that tonsillar CD4+ T cell can express various Th effector cytokines after short-term polyclonal stimulation, and that cytokine-producing CD4+ T cells were CD45RO+ T cells. In addition, we analyzed the co-expression of two or more kinds of cytokines at the level of a single cell. The results showed that tonsillar CD4+ T cells exhibited polyfunctionality by co-expressing two to five kinds of cytokines in the same time. These data furnished a basic theory for further understanding the differentiation of polyfunctional Th cells in human tonsils and their functions in resisting invasive microorganisms.

Hydrogen Sulfide Inhibits Autophagic Neuronal Cell Death by Reducing Oxidative Stress in Spinal Cord Ischemia Reperfusion Injury.

Autophagy is upregulated in spinal cord ischemia reperfusion (SCIR) injury; however, its expression mechanism is largely unknown; moreover, whether autophagy plays a neuroprotective or neurodegenerative role in SCIR injury remains controversial. To explore these issues, we created an SCIR injury rat model via aortic arch occlusion. Compared with normal controls, autophagic cell death was upregulated in neurons after SCIR injury. We found that autophagy promoted neuronal cell death during SCIR, shown by a significant number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling- (TUNEL-) positive cells colabeled with the autophagy marker microtubule-associated protein 1 light chain 3, while the autophagy inhibitor 3-methyladenine reduced the number of TUNEL-positive cells and restored neurological and motor function. Additionally, we showed that oxidative stress was the main trigger of autophagic neuronal cell death after SCIR injury and N-acetylcysteine inhibited autophagic cell death and restored neurological and motor function in SCIR injury. Finally, we found that hydrogen sulfide (H2S) inhibited autophagic cell death significantly by reducing oxidative stress in SCIR injury via the AKT-the mammalian target of rapamycin (mTOR) pathway. These findings reveal that oxidative stress induces autophagic cell death and that H2S plays a neuroprotective role by reducing oxidative stress in SCIR.

Nicotinamide Adenine Dinucleotide Protects against Spinal Cord Ischemia Reperfusion Injury-Induced Apoptosis by Blocking Autophagy.

The role of autophagy, neuroprotective mechanisms of nicotinamide adenine dinucleotide (NAD+), and their relationship in spinal cord ischemic reperfusion injury (SCIR) was assessed. Forty-eight Sprague-Dawley rats were divided into four groups: sham, ischemia reperfusion (I/R), 10 mg/kg NAD+, and 75 mg/kg NAD+. Western blotting, immunofluorescence, and immunohistochemistry were used to assess autophagy and apoptosis. Basso, Beattie, and Bresnahan (BBB) scores were used to assess neurological function. Expression levels of Beclin-1, Atg12-Atg5, LC3B-II, cleaved caspase 3, and Bax were upregulated in the I/R group and downregulated in the 75 mg/kg NAD+ group; p-mTOR, p-AKT, p62, and Bcl-2 were downregulated in the I/R group and upregulated in the 75 mg/kg NAD+ group. Numbers of LC3B-positive, caspase 3-positive, Bax-positive, and TUNEL-positive cells were significantly increased in the I/R group and decreased in the 75 mg/kg NAD+ group. The mean integrated option density of Bax increased and that of Nissl decreased in the I/R group, and it decreased and increased, respectively, in the 75 mg/kg NAD+ group. BBB scores significantly increased in the 75 mg/kg NAD+ group relative to the I/R group. No difference was observed between I/R and 10 mg/kg NAD+ groups for these indicators. Therefore, excessive and sustained autophagy aggravates SCIR; administration of NAD+ alleviates injury.

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.

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.

Memory-Like Antigen-Specific Human NK Cells from TB Pleural Fluids Produced IL-22 in Response to IL-15 or Mycobacterium tuberculosis Antigens.

Our previous result indicated that memory-like human natural killer (NK) cells from TB pleural fluid cells (PFCs) produced large amounts of IFN-γ in response to Bacille Calmette Guerin (BCG). Furthermore, recent studies have shown that human lymphoid tissues harbored a unique NK cell subset that specialized in production of interleukin (IL)-22, a proinflammatory cytokine that mediates host defense against pathogens. Yet little information was available with regard to the properties of IL-22 production by memory-like human NK cells. In the present study, we found that cytokines IL-15 induced and IL-12 enhanced the levels of IL-22 by NK cells from TB PFCs. In addition, IL-22 but not IL-17 was produced by NK cells from PFCs in response to BCG and M.tb-related Ags. More importantly, the subset of specific IL-22-producing NK cells were distinct from IFN-γ-producing NK cells in PFCs. CD45RO+ or CD45RO- NK cells were sorted, co-cultured with autologous monocytes and stimulated with BCG for the production of IL-22. The result demonstrated that CD45RO+ but not CD45RO- NK cells produced significantly higher level of IL-22. Anti-IL-12Rß1 mAbs (2B10) partially inhibit the expression of IL-22 by NK cells under the culture with BCG. Consistently, BCG specific IL-22-producing NK cells from PFCs expressed CD45ROhighNKG2Dhighgranzyme Bhigh. In conclusion, our data demonstrated that memory-like antigen-specific CD45RO+ NK cells might participate in the recall immune response for M. tb infection via producing IL-22, which display a critical role to fight against M. tb.

Mycobacterium tuberculosis-Specific IL-21+IFN-γ+CD4+ T Cells Are Regulated by IL-12.

In the current study of Mycobacterium tuberculosis (MTB)-specific T and B cells, we found that MTB-specific peptides from early secreted antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) induced the expression of IL-21 predominantly in CD4(+) T cells. A fraction of IL-21-expressing CD4(+) T cells simultaneously expressed Th1 cytokines but did not secrete Th2 or Th17 cytokines, suggesting that MTB-specific IL-21-expressing CD4(+) T cells were different from Th1, Th2 and Th17 subpopulations. The majority of MTB-specific IL-21-expressing CD4(+) T cells co-expressed IFN-γ and IL-21+IFN-γ(+)CD4(+) T cells exhibited obviously polyfunctionality. In addition, MTB-specific IL-21-expressing CD4(+) T cells displayed a CD45RO+CD62Ll(ow)CCR7(low)CD40L(high)ICOS(high) phenotype. Bcl-6-expression was significantly higher in IL-21-expressing CD4(+) T cells than IL-21-CD4(+) T cells. Moreover, IL-12 could up-regulate MTB-specific IL-21 expression, especially the frequency of IL-21(+)IFN-γ+CD4(+) T cells. Taken together, our results demonstrated that MTB-specific IL-21(+)IFN-γ(+)CD4(+) T cells from local sites of tuberculosis (TB) infection could be enhanced by IL-12, which have the features of both Tfh and Th1 cells and may have an important role in local immune responses against TB infection.