T-cell immune profile in blood of systemic mastocytosis: Association with disease features

BACKGROUND

Systemic mastocytosis (SM) is a heterogeneous disease characterized by an expansion of KIT-mutated mast cells (MC). KIT-mutated MC display activated features and release MC mediators that might act on the tumour microenvironment and other immune cells. Here, we investigated the distribution of lymphocyte subsets in blood of patients with distinct subtypes of SM and determined its association with other disease features.

METHODS

We studied the distribution of TCD4+ and TCD4- cytotoxic cells and their subsets, as well as total NK- and B cells, in blood of 115 SM patients-38 bone marrow mastocytosis (BMM), 67 indolent SM (ISM), 10 aggressive SM (ASM)- and 83 age-matched healthy donors (HD), using spectral flow cytometry and the EuroFlow Immunomonitoring panel, and correlated it with multilineage KITD816V , the alpha-tryptasemia genotype (HαT) and the clinical manifestations of the disease.

RESULTS

SM patients showed decreased counts (vs. HD) of TCD4- cytotoxic cells, NK cells and several functional subsets of TCD4+ cells (total Th1, Th2-effector memory, Th22-terminal effector and Th1-like Tregs), together with increased T-follicular-helper and Th1/Th17-like Treg counts, associated with different immune profiles per diagnostic subtype of SM, in multilineal versus MC-restricted KITD816V and in cases with a HαT+ versus HαT- genotype. Unique immune profiles were found among BMM and ISM patients with MC-restricted KITD816V who displayed HαT, anaphylaxis, hymenoptera venom allergy, bone disease, pruritus, flushing and GI symptoms.

CONCLUSION

Our results reveal altered T- and NK-cell immune profiles in blood of SM, which vary per disease subtype, the pattern of involvement of haematopoiesis by KITD816V , the HαT genotype and specific clinical manifestations of the disease.

Cotreatment With Clofazimine and Rapamycin Eliminates Drug-Resistant Tuberculosis by Inducing Polyfunctional Central Memory T-Cell Responses

Mycobacterium tuberculosis, the causative agent of tuberculosis, is acquiring drug resistance at a faster rate than the discovery of new antibiotics. Therefore, alternate therapies that can limit the drug resistance and disease recurrence are urgently needed. Emerging evidence indicates that combined treatment with antibiotics and an immunomodulator provides superior treatment efficacy. Clofazimine (CFZ) enhances the generation of T central memory (TCM) cells by blocking the Kv1.3+ potassium channels. Rapamycin (RAPA) facilitates M. tuberculosis clearance by inducing autophagy. In this study, we observed that cotreatment with CFZ and RAPA potently eliminates both multiple and extensively drug-resistant (MDR and XDR) clinical isolates of M. tuberculosis in a mouse model by inducing robust T-cell memory and polyfunctional TCM responses. Furthermore, cotreatment reduces the expression of latency-associated genes of M. tuberculosis in human macrophages. Therefore, CFZ and RAPA cotherapy holds promise for treating patients infected with MDR and XDR strains of M. tuberculosis.

Cytotoxic CD4 development requires CD4 effectors to concurrently recognize local antigen and encounter type I IFN-induced IL-15

Cytotoxic CD4 T cell effectors (ThCTLs) kill virus-infected major histocompatibility complex (MHC) class II+ cells, contributing to viral clearance. We identify key factors by which influenza A virus infection drives non-cytotoxic CD4 effectors to differentiate into lung tissue-resident ThCTL effectors. We find that CD4 effectors must again recognize cognate antigen on antigen-presenting cells (APCs) within the lungs. Both dendritic cells and B cells are sufficient as APCs, but CD28 co-stimulation is not needed. Optimal generation of ThCTLs requires signals induced by the ongoing infection independent of antigen presentation. Infection-elicited type I interferon (IFN) induces interleukin-15 (IL-15), which, in turn, supports CD4 effector differentiation into ThCTLs. We suggest that these multiple spatial, temporal, and cellular requirements prevent excessive lung ThCTL responses when virus is already cleared but ensure their development when infection persists. This supports a model where continuing infection drives the development of multiple, more differentiated subsets of CD4 effectors by distinct pathways.

The Cytokine Profile in Different Stages of Schistosomiasis Japonica

To explore and profile the level of cytokines in the sera of patients infected with Schistosoma japonicum to explore the helper T-cell response of patients either at the chronic or advanced stage of the disease. We randomly selected 58 subjects from several areas endemic for schistosomiasis japonica in China and collected serum samples to be tested for 18 different cytokines secreted by (1) Th1/Th2 cells (GM-CSF, IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-12p70, IL-10, IL-13, IL-18 and TNF-α) and (2) Th9/Th17/Th22/Treg cells (IL-9, IL-17A, IL-21, IL-22, IL-23 and IL-27). The Th1/Th2 cytokines in chronic patients were not significantly different from those in healthy people, while patients with advanced schistosomiasis had higher levels of IL-2, IL-23 and IL-27 and lower levels of IL-18 and IFN-γ. With respect to the Th9/Th17/Th22/Treg cell cytokines, there were higher levels of IL-23. Thus, a limited variation of the cytokine response between the three patient groups was evident, but only in those with advanced infection, while there was no difference between chronic schistosomiasis infection and healthy subjects in this respect. The cytokine expression should be followed in patients with advanced schistosomiasis who show a cytokine pattern of a weakened Th1 cell response and an increased Th17 response.

T-helper cells and their cytokines in pathogenesis and treatment of asthma

Prosperous advances in understanding the cellular and molecular mechanisms of chronic inflammation and airway remodeling in asthma have been made over the past several decades. Asthma is a chronic inflammatory disease of the airways characterized by reversible airway obstruction that is self-resolving or remits with treatment. Around half of asthma patients are "Type-2-high" asthma with overexpression of type 2 inflammatory pathways and elevated type 2 cytokines. When stimulated by allergens, airway epithelial cells secrete IL-25, IL-33, and TSLP to derive a Th2 immune response. First ILC2 followed by Th2 cells produces a series of cytokines such as IL-4, IL-5, and IL-13. T_FH cells control IgE synthesis by secreting IL-4 to allergen-specific B cells. IL-5 promotes eosinophil inflammation, while IL-13 and IL-4 are involved in goblet cell metaplasia and bronchial hyperresponsiveness. Currently, "Type-2 low" asthma is defined as asthma with low levels of T2 biomarkers due to the lack of reliable biomarkers, which is associated with other Th cells. Th1 and Th17 are capable of producing cytokines that recruit neutrophils, such as IFN-γ and IL-17, to participate in the development of "Type-2-low" asthma. Precision medicine targeting Th cells and related cytokines is essential in the management of asthma aiming at the more appropriate patient selection and better treatment response. In this review, we sort out the pathogenesis of Th cells in asthma and summarize the therapeutic approaches involved as well as potential research directions.

PCSK6 mediates Th1 differentiation and promotes chronic colitis progression and mucosal barrier injury via STAT1

This study was aimed at investigating the expression and role of proprotein convertase subtilisin/kexin type (PCSK6) in inflammatory bowel disease (IBD). DSS induced mouse colitis and mucosal barrier injury, down-regulation of TJ proteins, improvement of permeability, and increases of the proportions of Th1 and M1 macrophages. After PCSK6 knockdown, the colitis in KO mice was improved relative to WT mice, the TJ protein levels increased, and the proportions of Th1 and M1 macrophages decreased. STAT1 inhibitor treatment also inhibited chronic colitis in mice. As revealed by in-vitro experiments, PCSK6 overexpression promoted the transformation of Th0 into Th1, while PCSK6 silencing suppressed the transfection. COPI assay results revealed the presence of targeted binding relation between PCSK6 and STAT1. PCSK6 binds to STAT1 to promote STAT1 phosphorylation and regulate Th1 cell differentiation, thus promoting the M1 polarization of macrophages and aggravating colitis progression. PCSK6 is promising as the new target for the treatment of colitis.

OMIP-090: A 20-parameter flow cytometry panel for rapid analysis of cell diversity and homing capacity in human conventional and regulatory T cells

The panel was developed and optimized for monitoring changes in homing capacity and functional diversity of human CD4+ conventional and regulatory T cell subsets. The analysis was based on expression of only surface markers in freshly isolated peripheral blood mononuclear cells (PBMCs) to reduce at minimum any alteration due to permeabilization or freezing/thawing procedures. We included markers to assess the distribution of naïve and memory populations based on the expression of CD45RA, CCR7, CD25, CD28 and CD95 in both conventional and regulatory T cells. The identification of major functional subsets was performed using CCR4, CCR6, CCR10, CXCR3 and CXCR5. Homing capacity of these subsets to skin, airway tract, gut and inflammatory lesions could finally be assessed with the markers CLA, CCR3, CCR5 and integrin β7. The panel was tested on freshly isolated PBMCs from healthy donors and patients with allergic rhinitis or autoimmune disorders.

Follicular helper T lymphocytes in the endometria of patients with reproductive failure: Association with pregnancy outcomes and inflammatory status of the endometria

PROBLEM

The phenotypes and functions of B and CD4⁺ T-helper cell subsets during chronic inflammation of the endometria remain largely unexplored. This study aimed to investigate the characteristics and functions of follicular helper T (Tfh) cells to understand the pathological mechanisms of chronic endometritis (CE).

METHOD OF STUDY

Eighty patients who underwent hysteroscopic and histopathological examinations for CE were divided into three groups-those with positive results for hysteroscopy and CD138 staining (DP), negative results for hysteroscopy but positive CD138 staining (SP), and negative results for hysteroscopy and CD138 staining (DN). The phenotypes of B cells and CD4⁺ T-cell subsets were analyzed using flow cytometry.

RESULTS

CD38⁺ and CD138⁺ cells were mainly expressed in the non-leukocyte population of the endometria, and the endometrial CD19⁺ CD138⁺ B cells were fewer than the CD3⁺ CD138⁺ T cells. The percentage of Tfh cells increased with chronic inflammation in the endometria. Additionally, the elevated percentage of Tfh cells correlated with the number of miscarriages.

CONCLUSIONS

CD4⁺ T cells, particularly Tfh cells, may be critical in chronic endometrial inflammation and affect its microenvironment, thereby regulating endometrial receptivity, compared to B cells.

Th1 promotes M1 polarization of intestinal macrophages to regulate colitis-related mucosal barrier damage

This work aimed to investigate the role of helper T cell 1 (Th1) in chronic colitis and its immunoregulatory mechanism. The proportions of Th1 and Th2, and the levels of related cytokines in tissues from patients with inflammatory bowel disease (IBD; ulcerative colitis+Crohn's disease, UC+CD) were detected. DSS was used to induce the mouse model of IBD; thereafter, Th1 cells were induced in vitro and amplified before they were injected intraperitoneally. Later, the changes in life state and body weight of mice were observed, the proportion of M1 macrophages in mucosal tissues and mucosal barrier damage were detected. After treatment with macrophage scavenging agent (Clodronate Liposomes, CLL), the influence of Th1 on IBD mice was observed. Then, the intestinal macrophages were co-cultured with Th1 in vitro to observe the influence of Th1 on the polarization of intestinal macrophages. Besides, cells were treated with the STAT3 inhibitor to further detect the macrophage polarization level. Intestinal macrophages were later co-cultured with intestinal epithelial cells to observe the degree of epithelial cell injury. The Th1 proportions in intestinal tissues of UC and CD patients were higher than those in healthy subjects, but the difference in Th2 proportion was not significant. In the IBD mouse model, Th1 induced the M1 polarization of macrophages, aggravated the intestinal inflammatory response, and resulted in the increased mucosal barrier permeability. Pretreatment with CLL antagonized the effect of Th1 cells, reduced the intestinal tissue inflammatory response and mucosal barrier permeability.

Animal unit hygienic conditions influence mouse intestinal microbiota and contribute to T-cell-mediated colitis

Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders of the gastrointestinal tract with worldwide increasing incidence. Recent studies indicate that certain species of intestinal bacteria are strongly associated with IBD. Helper T lymphocytes are not only the key players in mediating host defense against a wide variety of pathogens but also contribute to pathogenesis of many immune-related diseases. Here, using the T cell transfer model of colitis, we observed that the mice maintained in a specific-pathogen free (SPF) unit after receiving naïve CD4⁺ T cells developed mild disease. The same mice developed different degrees of disease when they were maintained in a conventional animal facility (non-SPF), where some pathogens were detected during routine health monitoring. Consistently, increased circulating inflammatory cytokines as well as Th1 and Th17 cells were detected in mice housed in non-SPF units. 16S rRNA sequencing of feces samples enabled us to identify changes in the microbiota composition of mice kept in different facilities. Our data indicate that environmental factors influence gut microbiota composition of mice, leading to development of colitis in a T-cell-dependent manner. In conclusion, changes in environmental conditions and microbial status of experimental animals appear to contribute to progression of colitis.

Current Research Describing the Role of CD4+ T Lymphocyte Subsets in the Pathogenesis of Granulomatous Lobular Mastitis

Background: Granulomatous lobular mastitis (GLM) is a rare, benign, chronic inflammatory illness of the mammary gland with an unknown cause. Many scholars believe that the pathogenesis of GLM is mediated by autoimmunity. This article reviews the progress of the role of CD4+ T lymphocyte subsets in the development of GLM to explore potential therapeutic targets.Methods: Original articles from inception to October 2021 were systematically searched by two members on PubMed and China National Knowledge Infrastructure.Results: Current studies have confirmed the presence of disorders of several immune molecules in the serum and tissue microenvironment of GLM patients, including interleukin (IL) -2, IL-4, IL-6, and IL-10. This may be related to the dysregulation of Th1/Th2 and Th17/Treg balance.Conclusions: Altered expression and the malfunctioning of Th, Treg, and associated cytokines may contribute to GLM pathogenesis. Immune molecules and immune-related pathways may be potential targets and breakthroughs for future GLM treatment.

The Robustness of Cellular Immunity Determines the Fate of SARS-CoV-2 Infection

Two years after the appearance of the SARS-CoV-2 virus, the causal agent of the current global pandemic, it is time to analyze the evolution of the immune protection that infection and vaccination provide. Cellular immunity plays an important role in limiting disease severity and the resolution of infection. The early appearance, breadth and magnitude of SARS-CoV-2 specific T cell response has been correlated with disease severity and it has been thought that T cell responses may be sufficient to clear infection with minimal disease in COVID-19 patients with X-linked or autosomal recessive agammaglobulinemia. However, our knowledge of the phenotypic and functional diversity of CD8+ cytotoxic lymphocytes, CD4+ T helper cells, mucosal-associated invariant T (MAIT) cells and CD4+ T follicular helper (Tfh), which play a critical role in infection control as well as long-term protection, is still evolving. It has been described how CD8+ cytotoxic lymphocytes interrupt viral replication by secreting antiviral cytokines (IFN-γ and TNF-α) and directly killing infected cells, negatively correlating with stages of disease progression. In addition, CD4+ T helper cells have been reported to be key pieces, leading, coordinating and ultimately regulating antiviral immunity. For instance, in some more severe COVID-19 cases a dysregulated CD4+ T cell signature may contribute to the greater production of pro-inflammatory cytokines responsible for pathogenic inflammation. Here we discuss how cellular immunity is the axis around which the rest of the immune system components revolve, since it orchestrates and leads antiviral response by regulating the inflammatory cascade and, as a consequence, the innate immune system, as well as promoting a correct humoral response through CD4+ Tfh cells. This review also analyses the critical role of cellular immunity in modulating the development of high-affinity neutralizing antibodies and germinal center B cell differentiation in memory and long-lived antibody secreting cells. Finally, since there is currently a high percentage of vaccinated population and, in some cases, vaccine booster doses are even being administered in certain countries, we have also summarized newer approaches to long-lasting protective immunity and the cross-protection of cellular immune response against SARS-CoV-2.

Epigenetic regulation of inflammation by CxxC domain-containing proteins

Epigenetic regulation of gene transcription in the immune system is important for proper control of protective and pathogenic inflammation. Aberrant epigenetic modifications are often associated with dysregulation of the immune cells, including lymphocytes and macrophages, leading to pathogenic inflammation and autoimmune diseases. Two classical epigenetic markers-histone modifications and DNA cytosine methylation, the latter is the 5 position of the cytosine base in the context of CpG dinucleotides-play multiple roles in the immune system. CxxC domain-containing proteins, which basically bind to the non-methylated CpG (i.e., epigenetic "readers"), often function as "writers" of the epigenetic markers via their catalytic domain within the proteins or by interacting with other epigenetic modifiers. We herein report the most recent advances in our understanding of the functions of CxxC domain-containing proteins in the immune system and inflammation, mainly focusing on T cells and macrophages.

Reduction of Oxidative Stress in Peripheral Blood Mononuclear Cells Attenuates the Inflammatory Response of Fibroblast-like Synoviocytes in Rheumatoid Arthritis

The production and oxidation mechanism of reactive oxygen species (ROS) are out of balance in rheumatoid arthritis (RA). However, the correlation between ROS and T cell subsets in RA remains unclear. Peripheral blood mononuclear cells (PBMCs) from patients with RA (n = 40) and healthy controls (n = 10) were isolated from whole blood samples. Synovial tissues (n = 3) and synovial fluid (n = 10) were obtained from patients with RA. The repartition of T cell subsets and expression of ROS and cytokines were examined according to RA severity. Fibroblast-like synoviocytes (FLSs) from patients with RA were stimulated with PBMCs and the expression of inflammation-related molecules were measured by RT-PCR and cytokine array. Regulatory T cells from patients with moderate (5.1 > DAS28 ≥ 3.2) RA showed the highest expression of mitochondrial ROS among the groups based on disease severity. Although ROS levels steadily increased with RA severity, there was a slight decline in severe RA (DAS28 ≥ 5.1) compared with moderate RA. The expression of inflammatory cytokines in RA FLSs were significantly inhibited when FLSs were co-cultured with PBMCs treated with ROS inhibitor. These findings provide a novel approach to suppress inflammatory response of FLSs through ROS regulation in PBMCs.

T Cells: A Growing Universe of Roles in Neurodegenerative Diseases

T cells play a central role in homeostasis and host defense against infectious diseases. T cell dysregulation can lead to recognizing self-antigens as foreign antigens, causing a detrimental autoimmune response. T cell involvement in multiple sclerosis (MS), long understood to be an autoimmune-mediated neurodegenerative disease, is well characterized. More recently, a role for T cells has also been identified for the neurodegenerative diseases Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). Interestingly, several alleles and variants of human leukocyte antigen (HLA) genes have been classified as AD and PD risk genes. HLA codes for components of major histocompatibility complex (MHC) class I or class II, both of which are expressed by microglia, the innate immune cells of the central nervous system (CNS). Thus, both microglia and T cells may potentially interact in an antigen-dependent or independent fashion to shape the inflammatory cascade occurring in neurodegenerative diseases. Dissecting the antigen specificity of T cells may lead to new options for disease-modifying treatments in neurodegenerative diseases. Here, we review the current understanding of T cells in neurodegenerative diseases. We summarize the subsets of T cells, their phenotype and potential functions in animal models and in human studies of neurodegenerative diseases.

Distinct Roles of Vav Family Members in Adaptive and Innate Immune Models of Arthritis

Genetic evidence suggests that three members of the VAV family (VAV1, VAV2 and VAV3) of signal transduction proteins could play important roles in rheumatoid arthritis. However, it is not known currently whether the inhibition of these proteins protects against this disease and, if so, the number of family members that must be eliminated to get a therapeutic impact. To address this issue, we have used a collection of single and compound Vav family knockout mice in experimental models for antigen-dependent (methylated bovine serum albumin injections) and neutrophil-dependent (Zymosan A injections) rheumatoid arthritis in mice. We show here that the specific elimination of Vav1 is sufficient to block the development of antigen-induced arthritis. This protection is likely associated with the roles of this Vav family member in the development and selection of immature T cells within the thymus as well as in the subsequent proliferation and differentiation of effector T cells. By contrast, we have found that depletion of Vav2 reduces the number of neutrophils present in the joints of Zymosan A-treated mice. Despite this, the elimination of Vav2 does not protect against the joint degeneration triggered by this experimental model. These findings indicate that Vav1 is the most important pharmacological target within this family, although its main role is limited to the protection against antigen-induced rheumatoid arthritis. They also indicate that the three Vav family proteins do not play redundant roles in these pathobiological processes.

Low Concordance Between T-Cell Densities in Matched Primary Tumors and Liver Metastases in Microsatellite Stable Colorectal Cancer

Background

The subtype, density and location of tumor infiltrating T-cells are being explored as prognostic and predictive biomarkers in primary colorectal cancer (pCRC) and colorectal liver metastases (CLM). Very limited data exist comparing findings in pCRC and matched CLM.

Patients and methods

Fifty-eight patients with available pCRC and matched CLM (57/58 microsatellite stable) were included in this OSLO-COMET substudy. In immunohistochemically stained sections, total (T_tot), helper (TH), cytotoxic (CTL), and regulatory (Treg) T-cells were manually counted in hotspots from the invasive margin (IM), intratumor (IT), and tumor adjacent regions to determine T-cell densities.

Results

A striking accumulation of T-cells was found in IM of both pCRC and CLM with much lower densities in the IT region, exemplified by T_tot of 2838 versus 340 cells/mm², respectively, in CLM. The correlation at the individual level between T-cell densities in pCRC and corresponding CLM was poor for all regions and T-cell subtypes; for instance, the correlation coefficient (R²) for IM T_tot was 0.07. The IT TH : CTL and Treg : TH ratios were 2.94 and 0.44, respectively, in pCRC, and 1.84 and 0.24, respectively, in CLM.

Conclusion

The observed accumulation of T-cells in the IM regions of pCRC and CLM with low penetration to the IT regions, combined with high TH : CTL and Treg : TH ratios, point to the presence of an immune suppressive microenvironment. T-cell densities of CLM differed markedly from the matched pCRC, indicating that to evaluate T-cell biomarkers in metastasis, the commonly available pCRC cannot serve as a surrogate for the metastatic tumor.

Glycosides of Caulis Lonicerae inhibits the inflammatory proliferation of IL-1β-mediated fibroblast-like synovial cells cocultured with lymphocytes

Caulis Lonicerae, the dried stem of Lonicera japonica, has been confirmed to have antiinflammatory and antioxidant therapeutic effects. In the present study, we aimed to evaluate the functional mechanism of glycosides extracted from Caulis Lonicerae on the inflammatory proliferation of interleukin-1 beta (IL-1β)-mediated fibroblast-like synoviocytes (FLSs) from rats. Rat FLSs (RSC-364) co-cultured with lymphocytes induced by IL-1β were used as a cell model. Glycosides in a freeze-dried powder of aqueous extract from Caulis Lonicerae were identified using high-performance liquid chromatography-electrospray ionization/mass spectrometry. After treatment with glycosides, the inflammatory proliferation of FLS, induced by IL-1β, decreased significantly. Flow cytometry analysis showed that treatment with glycosides restored the abnormal balance of T cells by intervening in the proliferation and differentiation of helper T (Th) cells. Glycosides also inhibited the activation of Janus kinase signal transducer and activator of transcription (JAK-STAT) and nuclear factor (NF)-κB signaling pathways by suppressing the protein expression of key molecules in these pathways. Therefore, we concluded that the glycosides of Caulis Lonicerae can intervene in the differentiation of Th cells, suppressing the activation of JAK-STAT and NF-κB signaling pathways, contributing to the inhibitory effect on inflammatory proliferation of FLS co-cultured with lymphocytes induced by pro-inflammatory cytokines.

Oxytocin signalling in dendritic cells regulates immune tolerance in the intestine and alleviates DSS-induced colitis

BACKGROUND

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that is associated with immune dysfunction. Recent studies have indicated that the neurosecretory hormone oxytocin (OXT) has been proven to alleviate experimental colitis.

METHODS

We investigated the role of OXT/OXT receptor (OXTR) signalling in dendritic cells (DCs) using mice with specific OXTR deletion in CD11c+ cells (OXTRflox/flox×CD11c-cre mice) and a dextran sulfate sodium (DSS)-induced colitis model.

RESULTS

The level of OXT was abnormal in the serum or colon tissue of DSS-induced colitis mice or the plasma of UC patients. Both bone marrow-derived DCs (BMDCs) and lamina propria DCs (LPDCs) express OXTR. Knocking out OXTR in DCs exacerbated DSS-induced acute and chronic colitis in mice. In contrast, the injection of OXT-pretreated DCs significantly ameliorated colitis. Mechanistically, OXT prevented DC maturation through the phosphatidylinositol 4,5-bisphosphate 3-kinase (Pi3K)/AKT pathway and promoted phagocytosis, adhesion and cytokine modulation in DCs. Furthermore, OXT pre-treated DCs prevent CD4+ T cells differentiation to T helper 1 (Th1) and Th17.

CONCLUSIONS

Our results suggest that OXT-induced tolerogenic DCs efficiently protect against experimental colitis via Pi3K/AKT pathway. Our work provides evidence that the nervous system participates in the immune regulation of colitis by modulating DCs. Our findings suggest that generating ex vivo DCs pretreated with OXT opens new therapeutic perspectives for the treatment of UC in humans.

[Huangqin decoction alleviates ulcerative colitis by regulating ILC3s-TH cell response]

OBJECTIVE

To explore the effect of Huangqin decoction (HQD) on group 3 innate lymphoid cells (ILC3s) and helper T cells (Th) for treatment of ulcerative colitis (UC).

OBJECTIVE

Male Balb/c mice were randomly divided into control group, DSS group, mesalazine group (ME, 400 mg/kg), and 2.275 g/kg, 4.55 g/kg and 9.1 g/kg HQD groups. All the mice were given free access to normal chow. Except for those in the normal control group, all the mice were given 3% DSS solution for 7 days to establish models of UC. The mice in ME group and 3 HQD groups were given mesalazine or HQD via oral gavage at the specified doses once a day. Flow cytometry was performed to analyze the ILC3s, MHC Ⅱ, Th1 and Treg in the lamina propria lymphocytes in the colon. Milliplex was performed to determine cytokine levels of in the colon tissues.

OBJECTIVE

Compared with those in DSS group, the mice in the 3 HQD groups all showed obviously lessened symptoms of UC with significantl decreased DAI score (P < 0.001) and macroscopic score (P < 0.001). The results of flow cytometry showed that HQD treatment significantly increased the percentage of ILC3s (P < 0.05) and expression of MHCⅡ (P < 0.05), obviously reduced the proportion of Th1 (P < 0.05) but increased Treg cells (P < 0.05) in the colon tissues. Milliplex showed that HQD treatment significantly reduced the expressions of Th-related pro-inflammatory cytokines including IL-2 (P < 0.05), IL-17A (P < 0.05), IL-23 (P < 0.05), TNF-α (P < 0.05), and IFN-γ (P < 0.05).

OBJECTIVE

HQD alleviates DSS- induced UC in mice by increasing ILC3s and MHC Ⅱ expression to suppress the function of Th17 and Th1 cells and promote Treg and Th2 cells.

Influence of external forces on actin-dependent T cell protrusions during immune synapse formation

BACKGROUND INFORMATION

We have previously observed that in response to antigenic activation, T cells produce actin-rich protrusions that generate forces involved in T cell activation. These forces are influenced by the mechanical properties of antigen-presenting cells (APCs). However, how external forces, which can be produced by APCs, influence the dynamic of the actin protrusion remains unknown. In this study, we quantitatively characterised the effects of external forces in the dynamic of the protrusion grown by activated T cells.

RESULTS

Using a micropipette force probe, we applied controlled compressive or pulling forces on primary T lymphocytes activated by an antibody-covered microbead, and measured the effects of these forces on the protrusion generated by T lymphocytes. We found that the application of compressive forces slightly decreased the length, the time at which the protrusion stops growing and retracts and the velocity of the protrusion formation, whereas pulling forces strongly increased these parameters. In both cases, the applied forces did not alter the time required for the T cells to start growing the protrusion (delay). Exploring the molecular events controlling the dynamic of the protrusion, we showed that inhibition of the Arp2/3 complex impaired the dynamic of the protrusion by reducing both its maximum length and its growth speed and increasing the delay to start growing. Finally, T cells developed similar protrusions in more physiological conditions, that is, when activated by an APC instead of an activating microbead.

CONCLUSIONS

Our results suggest that the formation of the force-generating protrusion by T cells is set by an intracellular constant time and that its dynamic is sensitive to external forces. They also show that actin assembly mediated by actin-related protein Arp2/3 complex is involved in the formation and dynamic of the protrusion.

SIGNIFICANCE

Actin-rich protrusions developed by T cells are sensory organelles that serve as actuators of immune surveillance. Our study shows that forces experienced by this organelle modify their dynamic suggesting that they might modify immune responses. Moreover, the quantitative aspects of our analysis should help to get insight into the molecular mechanisms involved in the formation of the protrusion.

Elucidating the Functional Roles of Helper and Cytotoxic T Cells in the Cell-Mediated Immune Responses of Olive Flounder (Paralichthys olivaceus)

In higher vertebrates, helper and cytotoxic T cells, referred to as CD4 and CD8 T lymphocytes, respectively, are mainly associated with adaptive immunity. The adaptive immune system in teleosts involves T cells equivalent to those found in mammals. We previously generated monoclonal antibodies (mAbs) against olive flounder (Paralichthys olivaceus) CD4 T cells, CD4-1 and CD4-2, and used these to describe the olive flounder’s CD4 Tcell response during a viral infection. In the present study, we successfully produced mAbs against CD8 T lymphocytes and their specificities were confirmed using immuno-blotting, immunofluorescence staining, flow cytometry analysis andreverse transcription polymerase chain reaction (RT-PCR). The results showed that these mAbs are specific for CD8 T lymphocytes. We also investigated variations in CD4 and CD8 T cells populations, and analyzed the expression of immune-related genes expressed by these cells in fish infected with nervous necrosis virus or immunized with thymus dependent and independent antigens. We found that both CD4 and CD8 T lymphocyte populations significantly increased in these fish and Th1-related genes were up-regulated compared to the control group. Collectively, these findings suggest that the CD4 and CD8 T lymphocytes in olive flounder are similar to the helper and cytotoxic T cells found in mammals, and Th1 and cytotoxic immune responses are primarily involved in the early adaptive immune response against extracellular antigens.

T Lymphocytes and Testicular Immunity: A New Insight into Immune Regulation in Testes

The immune privilege of the testes is necessary to prevent immune attacks to gamete-specific antigens and paternal major histocompatibility complex (MHC) antigens, allowing for normal spermatogenesis. However, infection and inflammation of the male genital tract can break the immune tolerance and represent a significant cause of male infertility. Different T cell subsets have been identified in mammalian testes, which may be involved in the maintenance of immune tolerance and pathogenic immune responses in testicular infection and inflammation. We reviewed the evidence in the published literature on different T subtypes (regulatory T cells, helper T cells, cytotoxic T cells, γδ T cells, and natural killer T cells) in human and animal testes that support their regulatory roles in infertility and the orchitis pathology. While many in vitro studies have indicated the regulation potential of functional T cell subsets and their possible interaction with Sertoli cells, Leydig cells, and spermatogenesis, both under physiological and pathological processes, there have been no in situ studies to date. Nevertheless, the normal distribution and function of T cell subsets are essential for the immune privilege of the testes and intact spermatogenesis, and T cell-mediated immune response drives testicular inflammation. The distinct function of different T cell subsets in testicular homeostasis and the orchitis pathology suggests a considerable potential of targeting specific T cell subsets for therapies targeting chronic orchitis and immune infertility.

Immunophenotyping in pemphigus reveals a TH17/TFH17 cell-dominated immune response promoting desmoglein1/3-specific autoantibody production

BACKGROUND

T_H2 cells were thought to be a pivotal factor for initiation of the autoimmune blistering disease pemphigus. However, the role of other T-cell subsets in pemphigus pathogenesis remained unclear.

OBJECTIVE

We aimed to characterize the exact phenotype of T cells responsible for the development of pemphigus.

METHODS

Whole transcriptome shotgun sequencing was performed to determine differential gene expression in pemphigus lesions and skin of healthy individuals. The cutaneous cytokine signature was further evaluated by real-time quantitative PCR. In peripheral blood, the distribution of T_H cell and folliclular helper (T_FH) cell subsets was analyzed by flow cytometry. Finally, the capacity of T_H and T_FH cell subsets to induce desmoglein (Dsg)-specific autoantibodies by memory B cells was evaluated in coculture experiments.

RESULTS

Transcriptome analysis of skin samples identified an IL-17A-dominated immune signature in patients with pemphigus, and Kyoto Encyclopedia of Genes and Genomes pathway analysis confirmed the dominance of the IL-17A signaling pathway. Increased expression of IL17A and associated cytokines was also detected by real-time quantitative PCR comparing lesional with perilesional or healthy skin. Interestingly, utilization of flow cytometry showed that patients with active pemphigus had elevated levels of circulating IL-17⁺_, T_H17, T_FH17, and T_FH17.1 cells. Notably, levels of T_H17 and T_FH17 cells correlated with levels of Dsg-specific CD19⁺CD27⁺ memory B cells, and patients with acute pemphigus showed higher levels of Dsg3-autoreactive T_FH17 cells. Coculture experiments revealed T_FH17 cells as primarily responsible for inducing Dsg-specific autoantibody production by B cells.

CONCLUSION

Our findings show that T_FH17 cells are critically involved in the pathogenesis of pemphigus and offer novel targets for therapeutic intervention.

Cluster Analysis of Dry Eye Disease Models Based on Immune Cell Parameters - New Insight Into Therapeutic Perspective

Dry eye disease (DED) can be represented as a display of disease in the mucosal part of the eye. It is quite distinct from the retinal side of the eye which connects with the neurons and thus represents the neuroimmunological disease. DED can occur either by the internal damage of the T cells inside the body or by microbial infections. Here we summarize the most common animal model systems used for DED relating to immune factors. We aimed to identify the most important immune cell/cytokine among the animal models of the disease. We also show the essential immune factors which are being tested for DED treatment. In our results, both the mechanism and the treatment of its animal models indicate the involvement of Th1 cells and the pro-inflammatory cytokine (IL-1β and TNF-α) related to the Th1-cells. The study is intended to increase the knowledge of the animal models in the field of the ocular surface along with the opening of a dimension of thoughts while designing a new animal model or treatment paradigm for ocular surface inflammatory disorders.

Characterization of CD4-Positive Lymphocytes in the Antiviral Response of Olive Flounder (Paralichthys oliveceus) to Nervous Necrosis Virus

The presence of CD4 T lymphocytes has been described for several teleost species, while many of the main T cell subsets have not been characterized at a cellular level, because of a lack of suitable tools for their identification, e.g., monoclonal antibodies (mAbs) against cell markers. We previously described the tissue distribution and immune response related to CD3ε and CD4-1 T cells in olive flounder (Paralichthys oliveceus) in response to a viral infection. In the present study, we successfully produce an mAb against CD4-2 T lymphocytes from olive flounder and confirmed its specificity using immuno-blotting, immunofluorescence staining, flow cytometry analysis and reverse transcription polymerase chain reaction (RT-PCR). Using these mAbs, we were able to demonstrate that the CD3ε T cell populations contain both types of CD4⁺ cells, with the majority of the CD4 T cell subpopulations being CD4-1⁺/CD4-2⁺ cells, determined using two-color flow cytometry analysis. We also examined the functional activity of the CD4-1 and CD4-2 cells in vivo in response to a viral infection, with the numbers of both types of CD4 T cells increasing significantly during the virus infection. Collectively, these findings suggest that the CD4 T lymphocytes in olive flounder are equivalent to the helper T cells in mammals in terms of their properties and function, and it is the CD4-2 T lymphocytes rather than the CD4-1 T cells that play an important role in the Th1 immune response against viral infections in olive flounder.

CD4+ Resident Memory T Cells Mediate Long-Term Local Skin Immune Memory of Contact Hypersensitivity in BALB/c Mice

In allergic contact dermatitis (ACD) and contact hypersensitivity (CHS), the healed skin shows greater swelling than the naïve skin in the same individual upon re-exposure to the same hapten. This “local skin memory” (LSM) in healed skin was maintained for a prolonged period of time and mediated by skin CD8⁺-resident memory T (T_RM) cells in C57BL/6 mice. However, the number of CD4⁺ T cells is elevated in ACD-healed human skin, and the contribution of CD4⁺ T_RM cells to the formation of LSM currently remains unclear. We herein demonstrated that immediately after CHS subsided, the healed skin in BALB/c mice showed an accumulation of hapten-specific CD4⁺ and CD8⁺ T_RM cells, with a predominance of CD4⁺ T_RM cells. The presence of CD4⁺ or CD8⁺ T_RM cells in the healed skin was sufficient for the induction of a flare-up reaction upon a re-challenge. The CD4⁺ and CD8⁺ T_RM cells both produced interferon-γ and tumor necrosis factor early after the re-challenge. Moreover, while CD8⁺ T_RM cells gradually decreased over time and were eventually lost from the healed skin at 40–51 weeks after the resolution of CHS, the CD4⁺ T_RM cell numbers remained elevated during this period. The present results indicate that the long-term maintenance of LSM is mediated by CD4⁺ T_RM cells, and thus CD4⁺ T_RM cells are an important target for the treatment of recurrent human ACD.

Polysaccharide from Pycnoporus sanguineus ameliorates dextran sulfate sodium-induced colitis via helper T cells repertoire modulation and autophagy suppression

Inflammatory bowel disease (IBD) is a chronic autoimmune disease associated with various risk factors. Pycnoporus sanguineus (L.) Murrill is a saprotrophic fungus used worldwide for its industrial and medical purposes. Here, polysaccharide from P. sanguineus (PPS) was explored for its antiinflammatory potential in a murine colitis model of IBD induced by dextran sulfate sodium (DSS). PPS ameliorated the colitis as manifested by the lowered disease activity index (DAI), prolonged colon, and reduced serum lipopolysaccharide (LPS). PPS recovered the histological lesion by upregulating the expressions of Zonula occludens-1 (ZO-1), E-cadherin, and proliferating cell nuclear antigen (PCNA). PPS inhibited the helper T cells (Th)-mediated immune response by decreasing the proportions of Th cells (including Th2 cells, Th17 cells, and regulatory T cells), which was accompanied with reductions on myeloperoxidase (MPO) activity and releases of several interleukins and chemokines within the colon. Moreover, PPS exhibited an evident inhibition on autophagy, in which the ratio of light chain 3 (LC3) II/I was declined, while the expression of p62 and Beclin-1 was increased. The present study highlighted important clinical implications for the treatment application of PPS against IBD, which relies on the regulation of Th cells repertoire and autophagy suppression to restore epithelium barrier.

In vitro human helper T-cell assay to screen antibody drug candidates for immunogenicity

Monoclonal antibody (mAb) drugs offer a number of valuable treatments. Many newly developed mAb drugs include artificial modification of amino acid sequences from human origin, which may cause higher immunogenicity to induce anti-drug antibodies (ADA). If the immunogenicity of a new candidate can be understood in the nonclinical phase, clinical studies will be safer and the success rate of development improved. Empirically, in vitro immunogenicity assays with human cells have proved to be sufficiently sensitive to nonhuman proteins, but not to human/humanized mAb. To detect the weaker immunogenicity of human-based mAb, a more sensitive biomarker for in vitro assays is needed. The in vitro study here developed a proliferation assay (T_H cell assay) using flow cytometry analysis that can detect a slight increase in proliferating T_H cells. Samples from 218 donors treated with a low-immunogenic drug (etanercept) were measured to determine a positive threshold level. With this threshold, positive donor percentages among PBMC after treatment with higher-immunogenicity mAb drugs were noted, that is, 39.5% with humanized anti-human A33 antibody (hA33), 27.3% with abciximab, 25.9% with adalimumab, and 14.8% with infliximab. Biotherapeutics with low immunogenicity yielded values of 0% for basiliximab and 3.7% for etanercept. These data showed a good comparability with previously reported incidences of clinical ADA with the evaluated drugs. Calculations based on the data here showed that a T_H cell assay with 40 donors could provide statistically significant differences when comparing low- (etanercept) versus highly immunogenic mAb (except for infliximab). Based on the outcomes here, for screening purposes, a practical cutoff point of 3/20 positives with 20 donors was proposed to alert immunogenicity of mAb drug candidates.

Physcion-Matured Dendritic Cells Induce the Differentiation of Th1 Cells

In addition to their use as colorants, anthraquinone derivatives have numerous medical applications, for example, as antibacterial and antiinflammatory agents. We confirmed that physcion (an anthraquinone derivative) induces TNF-alpha production by macrophages and increased the expressions of surface molecules (CD40, CD80, and CD86) and major histocompatibility complex (MHC) II. Based on these results, we hypothesized that physcion might induce the maturation of dendritic cells (DCs) to antigen-presenting cells (APCs), and decided to conduct in vitro experiments using bone-marrow-derived DCs (BMDCs). Physcion was not toxic to DCs and increased the expression of surface molecules (e.g., CD40, CD80, CD86, and MHC II) and the production of cytokines (e.g., IL-12p70, IL-1beta, IL-6, and TNF-alpha), but not of IL-10. To confirm that DCs matured by physcion induce T-cell-immune responses, naive CD4⁺ T cells were treated with physcion-treated DCs or their supernatants. Physcion induced the maturation of DCs, which promoted the polarization of Th1 cells. Our results show physcion-induced DC maturation via TLR4, and that mature DCs promote the differentiation of Th1 cells without affecting the differentiation of Th2 cells. These findings show that physcion has potential use as a treatment for inflammatory diseases associated with Th1/Th2 cell imbalance.

Identification of lncRNA, MicroRNA, and mRNA-Associated CeRNA Network of Radiation-Induced Lung Injury in a Mice Model

Radiation-induced lung injury (RILI) can be challenging for thoracic radiotherapy, thus investigating its mechanisms of related pathophysiological process is needed. Long noncoding RNAs (lncRNAs) was found to participate in normal tissue damage induced by ionizing irradiation. Here, we first profiled the dysregulation of lncRNAs, microRNAs (miRNAs), and messenger RNAs (mRNAs) of RILI in mice model receiving 12 Gy thoracic irradiation. The lung tissue was collected 48 hours after irradiation, after which an RNA library was built by RNA sequencing. Compared with the control group, 461 mRNAs and 401 lncRNAs were significantly upregulated, while 936 mRNAs and 501 lncRNAs were significantly downregulated. Then we predicted target miRNAs of the dysregulated lncRNAs and the target mRNAs of these miRNAs. Next, functional annotations of these target mRNAs were performed. Results showed some pathways apparently dysregulated, such as Th1 and Th2 cell differentiation, Th17 cell differentiation, and hematopoietic cell lineage. Through this study, we also highlighted that T helpers could be vital in RILI through lncRNA-miRNA-mRNA network, therefore causing fibrosis, indicating that RNA dysregulation in early stage of RILI may cause severe late complications. Thus, research on the target mechanism and early intervention of lncRNAs with associated competing endogenous RNA network will benefit the treatment of RILI.

Single-Dose Vaccination with a Hepatotropic Adeno-associated Virus Efficiently Localizes T Cell Immunity in the Liver with the Potential To Confer Rapid Protection against Hepatitis C Virus

Hepatitis C virus (HCV) is a significant contributor to the global disease burden, and development of an effective vaccine is required to eliminate HCV infections worldwide. CD4⁺ and CD8⁺ T cell immunity correlates with viral clearance in primary HCV infection, and intrahepatic CD8⁺ tissue-resident memory T (T_RM) cells provide lifelong and rapid protection against hepatotropic pathogens. Consequently, we aimed to develop a vaccine to elicit HCV-specific CD4⁺ and CD8⁺ T cells, including CD8⁺ T_RM cells, in the liver, given that HCV primarily infects hepatocytes. To achieve this, we vaccinated wild-type BALB/c mice with a highly immunogenic cytolytic DNA vaccine encoding a model HCV (genotype 3a) nonstructural protein (NS5B) and a mutant perforin (pVAX-NS5B-PRF), as well as a recombinant adeno-associated virus (AAV) encoding NS5B (rAAV-NS5B). A novel fluorescent target array (FTA) was used to map immunodominant CD4⁺ T helper (T_H) cell and cytotoxic CD8⁺ T cell epitopes of NS5B in vivo, which were subsequently used to design a K^dNS5B_451-459 tetramer and analyze NS5B-specific T cell responses in vaccinated mice in vivo The data showed that intradermal prime/boost vaccination with pVAX-NS5B-PRF was effective in eliciting T_H and cytotoxic CD8⁺ T cell responses and intrahepatic CD8⁺ T_RM cells, but a single intravenous dose of hepatotropic rAAV-NS5B was significantly more effective. As a T-cell-based vaccine against HCV should ideally result in localized T cell responses in the liver, this study describes primary observations in the context of HCV vaccination that can be used to achieve this goal.IMPORTANCE There are currently at least 71 million individuals with chronic HCV worldwide and almost two million new infections annually. Although the advent of direct-acting antivirals (DAAs) offers highly effective therapy, considerable remaining challenges argue against reliance on DAAs for HCV elimination, including high drug cost, poorly developed health infrastructure, low screening rates, and significant reinfection rates. Accordingly, development of an effective vaccine is crucial to HCV elimination. An HCV vaccine that elicits T cell immunity in the liver will be highly protective for the following reasons: (i) T cell responses against nonstructural proteins of the virus are associated with clearance of primary infection, and (ii) long-lived liver-resident T cells alone can protect against malaria infection of hepatocytes. Thus, in this study we exploit promising vaccination platforms to highlight strategies that can be used to evoke highly functional and long-lived T cell responses in the liver for protection against HCV.

Rapid hepatitis C virus clearance by antivirals correlates with immune status of infected patients

Altered immune parameters associated with hepatitis C virus (HCV) genotype 1b infection and their correlation with virus eradication in direct-acting antivirals (DAA)-treated patients were examined. Thirty-one HCV-infected patients were treated with DAAs for 12 weeks. Pre-DAA-treatment and post-DAA-treatment sera were analyzed for cytokines/chemokines using MILLIPLEX MAP. Serum complement level and antibody neutralization activity were measured separately. Sera from 11 spontaneously cleared HCV subjects were included for comparison. Rapid virological responders (RVR) or end-of-treatment responders (EOTR) were defined as patients with HCV RNA negative at week 4 or positive at week 4 and negative at week 12, respectively. HCV RNA eradication and a decrease in liver fibrosis-related cytokines after treatment were observed when compared with pretreatment sera from RVR and EOTR. In pretreatment sera, interferons and T-helper 1 or 2 cell-associated cytokines/chemokines were significantly higher among RVR as compared with EOTR. Furthermore, serum complement and virus neutralizing antibody levels were higher in pretreatment RVR sera. Eradication of HCV RNA by DAA decreased liver fibrosis-related cytokines. Pretreatment sera from RVR displayed an enhanced cytokine/chemokine, complement and virus neutralizing antibody response as compared with EOTR sera. Our results suggested that enhanced host immune status may play an additive role on HCV RNA clearance by DAA.

Advances in asthma in 2017: Mechanisms, biologics, and genetics

This review summarizes some of the most significant advances in asthma research over the past year. We first focus on novel discoveries in the mechanism of asthma development and exacerbation. This is followed by a discussion of potential new biomarkers, including the use of radiographic markers of disease. Several new biologics have become available to the clinician in the past year, and we summarize these advances and how they can influence the clinical delivery of asthma care. After this, important findings in the genetics of asthma and heterogeneity in phenotypes of the disease are explored, as is the role the environment plays in shaping the development and exacerbation of asthma. Finally, we conclude with a discussion of advances in health literacy and how they will affect asthma care.

Effect of Liuweibuqi capsules on CD4+CD25+Foxp3+ regulatory T cells, helper T cells and lung function in patients with stable chronic obstructive pulmonary disease complicated with lung Qi deficiency

Background

Chronic obstructive pulmonary disease (COPD) is predicted to become the fifth leading cause of disability and the third leading cause of death around the world by 2020. Though it is potentially treatable and preventable, evidence of brain structural alterations in COPD remains sparse and conflicting. We aim to investigate the effect of Liuweibuqi capsules on CD4⁺CD25⁺ Forkhead box protein 3⁺ (Foxp3⁺) regulatory T cells (Tregs), helper T cells (Th) and lung function in patients with stable COPD complicated with lung Qi deficiency.

Methods

COPD patients with lung Qi deficiency [458] were assigned into non-smoking COPD (NS-COPD), non-smoking control (NS-control), smoking COPD (S-COPD) and smoking control (S-control) groups, and healthy volunteers [245] into the non-smoking healthy (NSH) and smoking healthy (SH) groups. Levels of inflammatory cytokines were detected by Enzyme-linked immunoassay (ELISA). Contents of inflammatory cells, inflammatory marker, and CD4⁺CD25⁺Fox3⁺Tregs were measured by flow cytometry. FEV1/FVC (%) and FEV1 (%) were detected by pulmonary function test apparatus. Correlation between FEV1 (%) and Th1, Th2, Th17, Th1/Th2 or CD4⁺CD25⁺Fox3⁺Tregs was analyzed by Spearman rank correlation test. The related factors affecting treatment efficacy was assessed by logistic analysis.

Results

COPD patients and smoking people showed higher level of INF-γ, IL-4, IL-17, Th1, Th2, Th17 and Th1/Th2 but lower level of CD4⁺CD25⁺Fox3⁺Tregs. Liuweibuqi capsules could decrease level of inflammatory cells, cytokines, and markers (especially Th17 and IL-17), and increase level of CD4⁺CD25⁺Fox3⁺Tregs. FEV1 (%) negatively correlated with Th1, Th2, Th17 and Th1/Th2 but positively correlated with CD4⁺CD25⁺Fox3⁺Tregs, and smoking may strengthen their correlation, but Liuweibuqi capsules may weaker their correlation. Levels of inflammatory cytokines, cells, marker, CD4⁺CD25⁺Fox3⁺Tregs, FEV1/FVC (%), FEV1 (%), smoking and Liuweibuqi capsules are factors affecting efficacy.

Conclusions

Taken together, our data support the notion that smoking is an important factor to induce and aggravate COPD. Liuweibuqi capsules could stimulate proliferation of CD4⁺CD25⁺Fox3⁺Tregs and decrease Th17 expression to improve the lung function in stable COPD patients with lung Qi deficiency, and it had obvious efficacy for smoking COPD patients.

Contribution of neuraminidase 3 to the differentiation of induced regulatory T cells

Neuraminidase family enzymes that hydrolyze the terminal sialic acid linkage in biomolecules are involved in various immune responses. We previously showed that Th1 and Th2 cells differentially express several neuraminidases. Herein, the expression of neuraminidases in induced regulatory T (iTreg) cells was investigated in comparison with that in other T-cell subsets. Contrary to the tendency toward higher neuraminidase 1 mRNA expression in in vitro-differentiated Th2 cells, compared to Th1, Th17 and iTreg cells, we observed significantly higher expression of neuraminidase 3 (Neu3) in iTreg cells. Furthermore, the expression of Neu3 in FoxP3⁺ CD62L^- spleen cells was higher than that in FoxP3⁺ CD62L⁺ and FoxP3^- cells. Lentiviral expression of Neu3 in naïve CD4⁺ T cells during the stimulation culture led to upregulation of FoxP3 expression. On the basis of these findings, we conclude that Neu3 contributes to the differentiation of iTreg cells by upregulation of FoxP3.

T follicular helper cells: a potential therapeutic target in follicular lymphoma

Follicular lymphoma (FL), the most common indolent B-cell non-Hodgkin lymphoma (B-NHL), is a germinal center (GC)-derived lymphoma. The mechanisms underlying B-cell differentiation/maturation in GCs could be also involved in their malignant transformation. Moreover, the non-malignant cell composition and architecture of the tumor microenvironment can influence FL development and outcome. Here, we review recent research advances on CD4 helper T cells in FL that highlight the pivotal role of T follicular helper (TFH) cells in a complex multicellular system where they interact with B cells during GC dynamics. After describing the mechanism of FL lymphomagenesis, we discuss the emerging evidence about TFH cell enrichment and involvement in FL tumorigenesis and in B-T cell interaction, TFH regulation by T follicular regulatory cells (TFR) and its potential effect on FL. Then, we provide an overview on the flexible interplay between the different CD4 T-cell subtypes and how this may be predicted in normal and pathologic contexts, according to the cell epigenetic state. Finally, we highlight the importance of targeting TFH cells in the clinic, summarize the main outstanding questions about TFH and TFR cells in FL, and describe strategies to potentiate FL therapy by taking into account TFH cells.

CD4+ T helper cells and regulatory T cells in active lupus nephritis: an imbalance towards a predominant Th1 response?

The objective of this study was to evaluate the frequency of CD4⁺ T cell subsets in peripheral blood mononuclear cells (PBMC), urine and renal tissue from patients with lupus nephritis (LN). PBMC and urinary cells were collected from 17 patients with active LN, 20 disease controls (DC) with primary glomerulonephritis and 10 healthy controls (HC) and were analysed by flow cytometry with markers for T helper type 1 (Th1), Th2, Th17 and regulatory T cells (T_reg ) cells. T cell subsets were assessed by immunohistochemistry from LN biopsy specimens from 12 LN patients. T cell subtypes in PBMC were re-evaluated at 6 months of therapy. CD4⁺ T cells were decreased in PBMC in LN compared with DC and HC (P = 0·0001). No differences were observed in urinary CD4⁺ T cell subsets between LN and DC. The frequency of urinary Th17 cells was higher in patients with non-proliferative than in proliferative LN (P = 0·041). CD3⁺ and T-box 21 ( Tbet+) cells were found in glomeruli and interstitium of LN patients, while forkhead box protein 3 (FoxP3), retinoid-related orphan receptor gamma (ROR-γ) and GATA binding protein 3 (GATA-3) were present only in glomeruli. Th1 cells in PBMC were correlated negatively with urinary Th1 cells (Rho = -0·531; P = 0·028) and with T_bet in renal interstitium (Rho = -0·782; P = 0·004). At 6 months, LN patients showed an increase in Th17 cells in PBMC. In conclusion, the inverse association between Th1 cells from PBMC and urinary/renal tissue indicate a role for Th1 in LN pathophysiology. Urinary Th17 cells were associated with less severe LN, and Th17 increased in PBMC during therapy. Urinary CD4⁺ T cells were not different between LN and DC.

The Role of the Level of Interleukin-33 in the Therapeutic Outcomes of Immunotherapy in Patients with Allergic Rhinitis

Introduction  Allergic rhinitis (AR) affects up to 40% of the population and results in nasal itching, congestion, sneezing, and clear rhinorrhea.

Objectives  This study aimed to evaluate the changes in the clinical symptoms and in the level of serum interleukin (IL)-33 before and after pollen immunotherapy (IT) in patients with AR.

Methods  The total symptom score and the levels of total immunoglobulin E (IgE) and IL-33 were determined in the serum of 10 non-allergic healthy controls and 45 patients with AR who were equally divided into 3 groups: GI (patients did not receive IT), GII (patients had received IT for 6 months) and GIII (patients had received IT for 2 years).

Results  There was a significantly higher concentration of IgE and IL-33 in the serum of patients with AR than in that of non-allergic patients. Furthermore, serum level of IL-33 decreased significantly after pollen IT. But, there was no significant reduction in the serum level of IL-33 between GII and GIII patients.

Conclusion  Our results show a clinical improvement associated with a decrease in serum level of IL-33 after pollen IT.

Nanoparticle-Formulated Curcumin Prevents Posttherapeutic Disease Reactivation and Reinfection with Mycobacterium tuberculosis following Isoniazid Therapy

Curcumin, the bioactive component of turmeric also known as “Indian Yellow Gold,” exhibits therapeutic efficacy against several chronic inflammatory and infectious diseases. Even though considered as a wonder drug pertaining to a myriad of reported benefits, the translational potential of curcumin is limited by its low systemic bioavailability due to its poor intestinal absorption, rapid metabolism, and rapid systemic elimination. Therefore, the translational potential of this compound is specifically challenged by bioavailability issues, and several laboratories are making efforts to improve its bioavailability. We developed a simple one-step process to generate curcumin nanoparticles of ~200 nm in size, which yielded a fivefold enhanced bioavailability in mice over regular curcumin. Curcumin nanoparticles drastically reduced hepatotoxicity induced by antitubercular antibiotics during treatment in mice. Most interestingly, co-treatment of nanoparticle-formulated curcumin along with antitubercular antibiotics dramatically reduced the risk for disease reactivation and reinfection, which is the major shortfall of current antibiotic treatment adopted by Directly Observed Treatment Short-course. Furthermore, nanoparticle-formulated curcumin significantly reduced the time needed for antibiotic therapy to obtain sterile immunity, thereby reducing the possibility of generating drug-resistant variants of the organisms. Therefore, adjunct therapy of nano-formulated curcumin with enhanced bioavailability may be beneficial to treatment of tuberculosis and possibly other diseases.

Inhibition of microRNA-34a ameliorates murine collagen-induced arthritis

Rheumatoid arthritis (RA) is one of the most frequently occurring autoimmne diseases, with symptoms including synovium hyperplasia, immune disorder, cartilage damage and bone resorption. It has previously been demonstrated that microRNA-34a (miR-34a) may participate in cell apoptosis, immune activation and bone metabolism, therefore the present study investigated the effects of miR-34a on RA. Collagen-induced arthritic (CIA) mice were employed as a murine model of experimental arthritis, and it was demonstrated that the level of miR-34a in the spleens, lymph nodes and synovium was increased in the CIA mice compared with normal DBA/1j mice. Administration of miR-34a antagomir, the chemically modified inhibitor, ameliorated CIA and delayed the onset of symptoms. Arthritis scores decreased and joint swelling was alleviated with the miR-34a antagomir treatment and the expression of inflammatory cytokines was decreased. miR-34a antagomir delivery significantly decreased the percentage of T cells present including T helper (Th) 1, Th2, Th17 and regulatory T cells. Furthermore miR-34a antagomir-treated CIA mice demonstrated decreased inflammatory-induced bone loss. Overall, it was observed that inhibition of miR-34a ameliorated murine arthritis, downregulated T cell percentage and cytokine expression, and suppressed bone loss. The experimental results suggest that inhibition of miR-34a may offer a novel alternative for the treatment of RA.

Soluble programmed death-1 levels are associated with disease activity and treatment response in patients with autoimmune hepatitis

PURPOSE

Autoimmune hepatitis (AIH) is a chronic liver disease caused by impaired immune regulation. Programmed death-1 (PD-1) is an inhibitory receptor mainly expressed by T cells and with its ligands, PD-L1 and PD-L2 present on antigen-presenting cells. We hypothesised the PD-1 axis to be impaired in AIH and investigated systemic levels of soluble(s) PD-1 and T cells ability to up-regulate PD-1 following in vitro activation in AIH patients.

MATERIALS AND METHODS

We included 67 AIH patients; 9 with active disease, 31 responders and 27 incomplete-responders to standard therapy. Forty-seven healthy controls (HC) were included for comparison. Soluble PD-1 was measured by enzyme-linked immunosorbent assay. The PD-1 expression on T cells was measured using flow cytometry before and after 48-h stimulation in vitro with CD3/CD28 in 13 AIH patients and 10 HC.

RESULTS

Soluble PD-1 was significantly elevated in AIH patients with active disease [0.24 ng/mL (range 0.16-0.28)] and in incomplete responders to standard therapy [0.17 (0.11-0.22)] compared with responders [0.11 (0.08-0.16), p = .008 and p = .01, respectively] and HC [0.12 (0.05-0.16), p = .02, both]. Following in vitro activation, PD-1 was significantly up-regulated (3.3-fold) on CD4⁺ T cells from AIH patients compared with HC (1.5-fold) (p = .0006).

CONCLUSIONS

AIH patients with active disease and incomplete response to standard treatment have similarly increased sPD-1 levels. Further, AIH patients have increased ability to up-regulate PD-1 following in vitro activation. Together these data suggests an impaired PD-1 axis in AIH.

BTLA identifies dysfunctional PD-1-expressing CD4+ T cells in human hepatocellular carcinoma

Although immunotherapy targeting programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) pathway is being applied in clinic, the response outcomes are heterogeneous, suggesting existences of distinctive subsets within PD-1-expressing T cells that react differently to PD-1/PD-L1 blockade. However, markers to demarcate these subsets in human cancers remain unclear. Here, we found that both PD-1 and B and T lymphocyte attenuator (BTLA) were significantly upregulated on CD4⁺ T cells from tumor compared with those from paired non-tumor liver in hepatocellular carcinoma (HCC) patients. Interestingly, over 85% BTLA⁺ CD4⁺ T cells were PD-1-expressing cells and represented about 50% PD-1⁺ CD4⁺ T cells in tumors, and that level of BTLA⁺PD-1⁺ tumor CD4⁺ T cells were selectively associated with advanced stage HCC. BTLA⁺ identified highly dysfunctional PD-1-expressing CD4⁺ T cell subset, whereas BTLA^- defined PD-1⁺ CD4⁺ T cells undergoing activation in HCC. Importantly, blockade of PD-L1 could restore the ability of IFNγ/TNF-α production in BTLA⁺PD-1⁺ tumor CD4⁺ T cells but partially suppressed the activation of BTLA^-PD-1⁺ CD4⁺ T cells. Moreover, we provided evidence that BTLA signals also participated in suppressing CD4⁺ T cell function in HCC. In conclusion, BTLA could identify distinct function of PD-1 expressing CD4⁺ T cells in human cancer, which might not only advance our understanding of inhibitory receptor blockade, but also provide new targets for clinical predictors of response to these immunotherapies.

Divergence of helper, cytotoxic, and regulatory T cells in the decidua from miscarriage

PROBLEM

The aim of this prospective study was to evaluate phenotypic differences of helper T (Th), cytotoxic T (Tc), and regulatory T (Treg) cells in the deciduae of missed miscarriage with a normal chromosome karyotype of a fetus (MN) and missed miscarriage with an abnormal chromosome karyotype of a fetus (MA).

METHODS OF STUDY

The decidua of 19 MN and 28 MA was obtained. Additionally, the decidua of 15 induced abortion (IA) and the endometrium of 19 non-pregnant women (EM) were obtained. IFN-γ(+) , IL-17(+) , CD25(high) Foxp3(+) cells in CD4(+) (Th) cells, and IFN-γ(+) cells in CD8(+) (Tc) cells were evaluated by flow cytometry.

RESULTS

The percentages of IFN-γ(+) Tc and CD4(+) CD25(high) Foxp3(+) (Treg) cells in MN were significantly increased as compared with MA and IA. The percentage of IFN-γ(+) Th in MN was increased as compared with IA.

CONCLUSION

Activation of IFN-γ(+) Tc and Treg cells in the decidua might be associated with the pathophysiology underlying MN.

Dysbiosis of gut microbiota induced the disorder of helper T cells in influenza virus-infected mice

It is widely understood that commensal microbiota contributes to the maintenance of intestinal homeostasis through dynamic interactions with a body's immunity. And the immune regulation is important for the influenza vaccine's effectiveness after body injection, however, the mechanism between commensal microbiota and vaccine's effectiveness remains unknown. The impact that individual bacteria species have on the balance of the systemic immune system beyond the local intestinal mucosal tissues also remains less clear, and the related mechanism is still unknown. In this study, through the administration of various antibiotics, we examined the balance of helper T cell subsets in mice after inoculating them with the influenza virus and then, attempted to imitate the clinical practice in which patients are always prescribed with an antibiotic treatment in flu season. The data indicates that the mice in each group present differential immune responses in terms of the makeup of helper T cell subsets, although the Th17 cell activity seems to not be involved in the systemic immune modulation in the mice that are susceptible to the intervention of antibiotic. Th1, Th2, and anti-inflammatory regulatory T cells have been implicated in the contribution to the systemic immune response influenced by the antibiotic-induced dysbiosis. Thus we believe that the normal intestinal flora could maintain the immune balance and inhibit the inflammatory responses, which may be useful for clinical application to take intestinal flora into consideration when influenza vaccination was used.

The life (and death) of CD4+ CD28(null) T cells in inflammatory diseases

Inflammation contributes to the development and perpetuation of several disorders and T lymphocytes orchestrate the inflammatory immune response. Although the role of T cells in inflammation is widely recognized, specific therapies that tackle inflammatory networks in disease are yet to be developed. CD4(+) CD28(null) T cells are a unique subset of helper T lymphocytes that recently shot back into the limelight as potential catalysts of inflammation in several inflammatory disorders such as autoimmunity, atherosclerosis and chronic viral infections. In contrast to conventional helper T cells, CD4(+) CD28(null) T cells have an inbuilt ability to release inflammatory cytokines and cytotoxic molecules that can damage tissues and amplify inflammatory pathways. It comes as no surprise that patients who have high numbers of these cells have more severe disease and poor prognosis. In this review, I provide an overview on the latest advances in the biology of CD4(+) CD28(null) T cells. Understanding the complex functions and dynamics of CD4(+) CD28(null) T cells may open new avenues for therapeutic intervention to prevent progression of inflammatory diseases.

Effect of Lactobacillus salivarius on Th1/Th2 cytokines and the number of spleen CD4⁺ CD25⁺ Foxp3⁺ Treg in asthma Balb/c mouse

BACKGROUND

Bronchial asthma is a chronic airway inflammatory disease that involves T lymphocytes.

METHODS

In order to explore the effect of Lactobacillus salivarius on Th1/Th2 cytokines and the number of spleen CD4(+) CD25(+) Foxp3(+) Treg in asthma Balb/c mouse, we constructed acute asthma model with ovalbumin to observe the mouse behavior change in Balb/c mice. The expression of GATA-3 mRNA and T-bet mRNA was measured by real-time PCR. The proportion of CD4(+) CD25(+) Foxp3(+) Treg/CD4(+) was determined by flow cytometry.

RESULTS

The results demonstrated that oral gavage with Lactobacillus salivarius before sensitization could alleviate the clinical symptoms, airway hyper-reactivity and airway inflammation in asthma mouse to some extent; Lactobacillus salivarius may improve the imbalance of Th1/Th2 in asthma mouse through increasing the expression of T-bet mRNA at the transcriptional level and inhibiting the expression of GATA-3 mRNA simultaneously.

CONCLUSION

CD4(+) CD25(+) Foxp3(+) Treg cells may be involved in the pathogenesis of bronchial asthma, and may be the upstream regulatory mechanism of the improvement of Th1/Th2 imbalance by Lactobacillus salivarius.

Memory T follicular helper CD4 T cells

T follicular helper (Tfh) cells are the subset of CD4 T helper cells that are required for generation and maintenance of germinal center reactions and the generation of long-lived humoral immunity. This specialized T helper subset provides help to cognate B cells via their expression of CD40 ligand, IL-21, IL-4, and other molecules. Tfh cells are characterized by their expression of the chemokine receptor CXCR5, expression of the transcriptional repressor Bcl6, and their capacity to migrate to the follicle and promote germinal center B cell responses. Until recently, it remained unclear whether Tfh cells differentiated into memory cells and whether they maintain Tfh commitment at the memory phase. This review will highlight several recent studies that support the idea of Tfh-committed CD4 T cells at the memory stage of the immune response. The implication of these findings is that memory Tfh cells retain their capacity to recall their Tfh-specific effector functions upon reactivation to provide help for B cell responses and play an important role in prime and boost vaccination or during recall responses to infection. The markers that are useful for distinguishing Tfh effector and memory cells, as well as the limitations of using these markers will be discussed. Tfh effector and memory generation, lineage maintenance, and plasticity relative to other T helper lineages (Th1, Th2, Th17, etc.) will also be discussed. Ongoing discoveries regarding the maintenance and lineage stability versus plasticity of memory Tfh cells will improve strategies that utilize CD4 T cell memory to modulate antibody responses during prime and boost vaccination.