Th2 Cytokine Production Research Articles

STAT1 expression controls CD4 T cell Th1 and Th17 effector functionality during influenza virus infection

Abstract Most CD4 T cells primed by influenza A virus (IAV) express the transcription factor T-bet, the Th1 ‘master regulator’, and are marked by phenotypic and functional Th1 hallmarks. The extent to which STAT1 and STAT4 activation, both needed for maximal T-bet induction in vitro, are required to direct IAV-primed CD4 T cell responses is not clear. Here, we transferred STAT-deficient (STAT −/−) or wildtype CD4 T cells recognizing IAV to congenic wildtype mice, challenged them with IAV, and analyzed the donor cells in the infected lungs 7 days later. STAT1 −/−cells were barely detected in host mice but were rescued when NK cells were depleted in host mice prior to infection. Functional analysis revealed compromised Th1 identity in STAT1 −/−effectors mirroring that of T-bet −/−cells. However, while T-bet −/−cells develop Th17 functions, STAT1 −/−cells do not. We show that this is due to alternative receipt of type I IFN signals by the STAT1 −/−cells, as blocking type I IFN receptor in IAV-primed mice promotes robust Th17 identity in STAT1 −/−but not in WT cells. In contrast, STAT4 −/−donor cells closely resemble WT cells. To ask if IAV-primed CD4 T cells can respond to STAT4-activating signals we treated mice receiving STAT4 −/−donor cells with IL-12 during IAV infection. IL-12 dramatically increased T-bet and Th1 cytokine production of wildtype, but not of STAT4 −/−or T-bet −/−cells. Our findings thus indicate that STAT1 activation is sufficient to direct prototypical antiviral effector identity, but that this response is not fully Th1-polarized without therapeutic STAT4 activation. This work impacts vaccine strategies that aim to promote protective T cell immunity against IAV by shaping the priming environment with STAT-activating cytokine signals.

A bifurcated role for c-Maf in Th2 and Tfh2 cells during helminth infection

Differences in transcriptomes, transcription factor usage, and function have identified T follicular helper 2 (Tfh2) cells and T helper 2 (Th2) cells as distinct clusters of differentiation 4+",(CD4) T-cell subsets in settings of type-2 inflammation. Although the transcriptional programs driving Th2 cell differentiation and cytokine production are well defined, dependence on these classical Th2 programs by Tfh2 cells is less clear. Using cytokine reporter mice in combination with transcription factor inference analysis, the b-Zip transcription factor c-Maf and its targets were identified as an important regulon in both Th2 and Tfh2 cells. Conditional deletion of c-Maf in T cells confirmed its importance in type-2 cytokine expression by Th2 and Tfh2 cells. However, while c-Maf was not required for Th2-driven helminth clearance or lung eosinophilia, it was required for Tfh2-driven Immunoglobulin E production and germinal center formation. This differential regulation of cell-mediated and humoral immunity by c-Maf was a result of redundant pathways in Th2 cells that were absent in Tfh2 cells, and c-Maf-specific mechanisms in Tfh2 cells that were absent in Th2 cells. Thus, despite shared expression by Tfh2 and Th2 cells, c-Maf serves as a unique regulator of Tfh2-driven humoral hallmarks during type-2 immunity.

Thelper1 and T helper2 cytokine production patterns in stressed beta2-adrenergic receptor-deficient mice during chlamydia genital infection.

Murine CD4+ T cells have two distinct cytokine secretion patterns to play different functions. We have demonstrated that cold-induced stress (CIS) suppresses the immune system leading to increased intensity of Chlamydia muridaum in mice. We have reported that beta2-adrenergic receptor (b2-AR) knockout (KO) mice resist chlamydia genital infection. However, the cytokine profile of CD4+ T cells is not well explored. This study aimed to determine the cytokine production of Th1 and Th2 types in stressed and non-stressed b2-AR KO mice. We investigated the cytokine production levels of stressed and non-stressed mice during C. muridarum genital infection. Significantly increased production of cytokines was observed in plates pre-coated with anti-CD3/CD28 or in the presence of Con A or LPS. A decrease in the production of IFN-g and IL-2, whereas an increase in the secretion of IL-10, IL-13, and IL-23 in CD4+ T cells of stressed wild-type mice was obtained; however, the secretion of IFN-g and IL-2 was restored in T cells of b2-AR KO mice. Moreover, in vitro proliferation of CD4 T cells in the presence of b2-AR antagonists, ICI 118, 551 stimulated the production of Th1 cytokines, whereas b2-AR agonist, Fenoterol, decreased the production of Th1-type cytokines. Overall, Th1 cytokine responses are reduced in stressed mice suggesting that the cytokine status was polarized toward a Th2 immune response that can be restored by removing b2-AR from immune cells.

Abstract 345: Cutaneous T-cell lymphoma: ectopic expression of gametocyte specific factor 1 (GTSF1) stimulates the Th phenotype

Abstract Diagnosis of Cutaneous T-Cell Lymphomas (CTCL) can take up to 6 years, increasing the risk of disease progression in these patients. Transcriptomic analyses have helped identify several diagnosis biomarkers, such as TOX, KIRD3DL2, GTSF1 and others. Although not officially a Cancer-Testis (CT) antigen, ectopic expression of Gametocyte Specific Factor 1 (GTSF1), presents the same advantages than CT antigens. Its germline-cell restricted expression potentially makes this gene easily identifiable by the immune system and a therapeutic target with less side effects. The role of GTSF1 has been elucidated in mice, where it controls retrotransposon expression during germ-cell development. Here, we investigate the molecular function of GTSF1 in CTCL. Using shRNA-mediated GTSF1 knockdown in CTCL cell lines, our current work demonstrates an unexpected role of GTSF1 regulating the Th phenotype of CTCL cells. With multiple approaches (qRT-PCR, Western blotting and a dual-luciferase based retrotransposition assay) we concluded that GTSF1 knockdown does not lead to retrotransposon reactivation. Transcriptome analysis with RNA-Seq, followed by differential gene expression analysis with DESeq2 and pathway enrichment analysis with GO, KEGG, Reactome and WikiPathways, suggested an involvement of GTSF1 in the Th phenotype of CTCL cells. Differential gene expression analysis revealed 12,496 differentially expressed genes (p adjusted < 0.05). Pathway enrichment analysis demonstrated an enrichment of several pathways including response to stimulus, immune response, response to cytokine and inflammatory response. More specifically, GTSF1 knockdown leads to an upregulation of the key cytokines associated with a Th1 phenotype, IFNG and TNF. Disease progression of CTCL is associated with a decrease in Th1 cytokine production and an enhanced Th2 cytokine production by malignant T cells. These findings shed light on the molecular function of GTSF1 as a regulator of the Th phenotype in CTCL and paves the way for the development of a valuable treatment target for CTCL patients. Citation Format: Amelia Martínez Villarreal, Ivan Litvinov. Cutaneous T-cell lymphoma: ectopic expression of gametocyte specific factor 1 (GTSF1) stimulates the Th phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 345.

Changes in cervical cytokine profiles following focused ultrasound treatment for high-risk human papillomavirus infection-related low-grade cervical lesions.

To evaluate the changes of cervical soluble immune markers after focused ultrasound (FU) treatment to explore the underlying local immune effects of FU in the treatment of high-risk human papillomavirus (HR-HPV) infection-related low-grade squamous intraepithelial lesion (LSIL). A total of 35 patients diagnosed with HR-HPV infection-related histological LSIL who met the inclusion criteria were enrolled in this prospective study and treated with FU. The authors used cytometric bead array to measure T-helper type 1 (Th1) cytokine (interleukin [IL] 2, tumor necrosis factor, and interferon γ) and Th2 cytokine (IL-4, IL-5, IL-6, and IL-10) levels in the cervicovaginal lavage of patients before and 3 months after FU treatment. After FU treatment, the concentrations of Th2 cytokines IL-5 and IL-6 were significantly lower than those before FU treatment (P = 0.044 and P = 0.028, respectively). HR-HPV infection was cleared in 27 patients, with a clearance rate of 77.1% (27 of 35). The concentration of IL-4 in patients with HR-HPV clearance after FU treatment was significantly lower than that in patients without HR-HPV clearance (P = 0.045). FU can inhibit the production of certain Th2 cytokines and may improve the local immune status of the cervix, thereby eliminating HR-HPV infection.

PD-1/PD-L1 Control of Antigen-Specifically Activated CD4 T-Cells of Neonates

Newborns are highly susceptible to infections; however, the underlying mechanisms that regulate the anti-microbial T-helper cells shortly after birth remain incompletely understood. To address neonatal antigen-specific human T-cell responses against bacteria, Staphylococcus aureus (S. aureus) was used as a model pathogen and comparatively analyzed in terms of the polyclonal staphylococcal enterotoxin B (SEB) superantigen responses. Here, we report that neonatal CD4 T-cells perform activation-induced events upon S. aureus/APC-encounter including the expression of CD40L and PD-1, as well as the production of Th1 cytokines, concomitant to T-cell proliferation. The application of a multiple regression analysis revealed that the proliferation of neonatal T-helper cells was determined by sex, IL-2 receptor expression and the impact of the PD-1/PD-L1 blockade. Indeed, the treatment of S. aureus-activated neonatal T-helper cells with PD-1 and PD-L1 blocking antibodies revealed the specific regulation of the immediate neonatal T-cell responses with respect to the proliferation and frequencies of IFNγ producers, which resembled in part the response of adults' memory T-cells. Intriguingly, the generation of multifunctional T-helper cells was regulated by the PD-1/PD-L1 axis exclusively in the neonatal CD4 T-cell lineage. Together, albeit missing memory T-cells in neonates, their unexperienced CD4 T-cells are well adapted to mount immediate and strong anti-bacterial responses that are tightly controlled by the PD-1/PD-L1 axis, thereby resembling the regulation of recalled memory T-cells of adults.

The Dual Benefit of Sulfasalazine on Pneumocystis Pneumonia-Related Immunopathogenesis and Antifungal Host Defense Does Not Require IL-4Rα-Dependent Macrophage Polarization.

Pneumocystis is a respiratory fungal pathogen that is among the most frequent causes of life-threatening pneumonia (PcP) in immunocompromised hosts. Alveolar macrophages play an important role in host defense against Pneumocystis, and several studies have suggested that M2 polarized macrophages have anti-Pneumocystis effector activity. Our prior work found that the immunomodulatory drug sulfasalazine (SSZ) provides a dual benefit during PcP-related immune reconstitution inflammatory syndrome (IRIS) by concurrently suppressing immunopathogenesis while also accelerating macrophage-mediated fungal clearance. The benefits of SSZ were associated with heightened Th2 cytokine production and M2 macrophage polarization. Therefore, to determine whether SSZ improves the outcome of PcP through a mechanism that requires Th2-dependent M2 polarization, RAG2-/- mice lacking interleukin 4 receptor alpha chain (IL-4Rα) on macrophage lineage cells were generated. As expected, SSZ treatment dramatically reduced the severity of PcP-related immunopathogenesis and accelerated fungal clearance in immune-reconstituted RAG2-/- mice. Similarly, SSZ treatment was also highly effective in immune-reconstituted RAG2/IL-4Rα-/- and RAG2/gamma interferon receptor (IFN-γR)-/- mice, demonstrating that neither IL-4Rα-dependent M2 nor IFN-γR-dependent M1 macrophage polarization programs were required for the beneficial effects of SSZ. Despite the fact that macrophages from RAG2/IL-4Rα-/- mice could not respond to the Th2 cytokines IL-4 and IL-13, M2-biased alveolar macrophages were identified in the lungs following SSZ treatment. These data demonstrate that not only does SSZ enhance phagocytosis and fungal clearance in the absence of macrophage IL-4Rα signaling, but also that SSZ promotes M2 macrophage polarization in an IL-4Rα-independent manner. These findings could have implications for the treatment of PcP and other diseases in which M2 polarization is beneficial.

Cannabinoid Receptor 1 Agonist ACEA and Cannabinoid Receptor 2 Agonist GW833972A Attenuates Cell-Mediated Immunity by Different Biological Mechanisms

Cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2) are components in the endocannabinoid system that play significant roles in regulating immune responses. There are many agonists for the cannabinoid receptors; however, their effects on T cell regulation have not been elucidated. In the present study, we determined the effects of the CB1 selective agonist ACEA and the CB2 selective agonist GW833972A on T cell responses. It was found that both agonists impaired anti-CD3 monoclonal antibody induced T cell proliferation. However, ACEA and GW833972A agonists down-regulated the expression of activation markers on CD4+ and CD8+ T cells and co-stimulatory molecules on B cells and monocytes in different manners. Moreover, only GW833972A suppressed the cytotoxic activities of CD8+ T cells without interfering in the cytotoxic activities of CD4+ T cells and NK cells. In addition, the CB2 agonist, but not CB1 agonist, caused the reduction of Th1 cytokine production. Our results demonstrated that the CB1 agonist ACEA and CB2 agonist GW833972A attenuated cell-mediated immunity in different mechanisms. These agonists may be able to be used as therapeutic agents for inducing T cell hypofunction in inflammatory and autoimmune diseases.

Human salivary protein-derived peptides specific-salivary SIgA antibodies enhanced by nasal double DNA adjuvant in mice play an essential role in preventing Porphyromonas gingivalis colonization: an in-vitro study

BackgroundWe previously showed that fimbriae-bore from Poryphyromonas gingivalis (Pg), one of the putative periodontopathogenic bacteria specifically bound to a peptide domain (stat23, prp21) shared on statherin or acidic proline-rich protein 1 (PRP1) molecule of human salivary proteins (HSPs). Here, we investigated whether the nasal administration of DNA plasmid expressing Flt3 ligand (pFL) and CpG oligodeoxynucleotide 1826 as double DNA adjuvant (dDA) with stat23 and prpr21 induces antigen (Ag)-specific salivary secretory IgA (SIgA) antibodies (Abs) in mice. Further, we examined that stat23- and prpr21-specific salivary SIgA Abs induced by dDA have an impact on Pg-binding to human whole saliva-coated hydroxyapatite beads (wsHAPs).Material and methodsC57BL/6N mice were nasally immunized with dDA plus sta23 or/and prp21 peptide as Ag four times at weekly intervals. Saliva was collected one week after the final immunization and was subjected to Ag-specific ELISA. To examine the functional applicability of Ag-specific SIgA Abs, SIgA-enriched saliva samples were subjected to Pg binding inhibition assay to wsHAPs.ResultsSignificantly elevated levels of salivary SIgA Ab to stat23 or prp21 were seen in mice given nasal stat23 or prp21 with dDA compared to those in mice given Ag alone. Of interest, mice nasally given the mixture of stat23 and prp21 as double Ags plus dDA, resulted in both stat23- and prp21-specific salivary SIgA Ab responses, which are mediated through significantly increased numbers of CD11c+ dendritic cell populations and markedly elevated Th1 and Th2 cytokines production by CD4+ T cells in the mucosal inductive and effector tissues. The SIgA Ab-enriched saliva showed significantly reduced numbers of live Pg cells binding to wsHAPs as compared with those in mice given double Ags without dDA or naïve mice. Additionally, saliva from IgA-deficient mice given nasal double Ags plus dDA indicated no decrease of live Pg binding to wsHAPs.ConclusionThese findings show that HSP-derived peptides-specific salivary SIgA Abs induced by nasal administration of stat23 and prp21 peptides plus dDA, play an essential role in preventing Pg attachment and colonization on the surface of teeth, suggesting a potency that the SIgA may interrupt and mask fimbriae-binding domains in HSPs on the teeth.

Construction of a novel TROP2/CD3 bispecific antibody with potent antitumor activity and reduced induction of Th1 cytokines

Many cancers, including triple-negative breast cancer, overexpress TROP2 on the surface of tumor cells. TROP2 has become a promising tumor associated antigen for the development of novel antibody-based targeted therapy. Herein, we constructed a novel bispecific antibody with the ability to simultaneously target TROP2 on the tumor surface and bind to CD3 to activate T cells. Given that the excessive production of Th1 cytokines induced by CD3-mediated T-cell overactivation may lead to toxicity in the clinic, we devised a strategy to modify this CD3-induced T cell activation by a two-step reduction in the bispecific antibody binding affinity for CD3 to a level that retained the ability of the bispecific antibody to effectively inhibit tumor growth while greatly reducing the amount of Th1 cytokines secreted by T cells. Thus, we provide insight into the design of T cell engagers that exhibit a promising toxicity profile while retaining inhibitory effects on tumor growth.

CFTR deficiency increases Th2 cytokine production and allergic airway inflammation in mice

The adaptive immune system is increasingly appreciated for contributions to the exuberant and maladaptive immune response in Cystic Fibrosis (CF). We hypothesized that 1) CFTR-deficiency in mouse Th2 cells increases Th2 cytokine production, 2) CF mice have increased allergic inflammation when challenged with inhaled allergen, and 3) GATA-3 expression is increased in murine CFTR-deficient Th2 cells.

Anti-Atopic Activities of Sargassum horneri Hot Water Extracts in 2,4-Dinitrochlorobezene-Induced Mouse Models.

Atopic dermatitis (AD) is a chronic inflammation associated with skin hypersensitivity caused by environmental factors. The objent of this study was to assess the hot water extracts of Sargassum horneri (SHHWE) on AD. AD was induced by spreading 2,4-dinitrochlorobenzene (DNCB) on the BALB/c mice. The efficacy of SHHWE was tested by observing the immunoglobulin E (IgE), cytokine, skin clinical severity score and cytokine secretions in concanavalin A (Con A)-stimulated splenocytes. The levels of interleukine (IL)-4, IL-5 and IgE, the pro-inflammatory cytokines that are closely related, were notably suppressed in a does-dependent manner by SHHWE, whereas the level of interferon γ (IFN-γ), the atopy-related Th1 cytokine inhibiting the production of Th2 cytokines, was increased. Therefore, these results show that SHHWE has a potent anti-inhibitory effect on AD and is highly valuable for cosmetic development.

Specific immunoglobulin G4 correlates with Th2 cytokine reduction in patients with allergic asthma treated by Dermatophagoides pteronyssinus subcutaneous immunotherapy

BackgroundThe modulations of lymphocyte subsets and cytokine production due to subcutaneous allergen immunotherapy (SCIT) are not fully clarified. ObjectiveWe investigated the changes in T-lymphocyte subsets and serum Dermatophagoides pteronyssinus-specific immunoglobulin G4 (Der-p sIgG4), as well as cytokine production during Der-p SCIT, in patients with allergic asthma. MethodsThis study involved 20 patients with allergic asthma who were receiving 156-week Der-p SCIT and 20 patients without SCIT (non-SCIT). We measured symptom and medication scores (SMS), serum Der-p sIgG4 levels, CD4+CD25+Foxp3+ T regulatory (Treg), CD4+IL-4−IFN-γ+ T-helper (Th) 1, and CD4+IL-4+IFN-γ− Th2 lymphocyte percentages in peripheral blood mononuclear cells (PBMCs) with/without Der-p extract stimulation at weeks 0, 4, 12, 16, 52, 104, and 156. Cytokine release inhibition assays were performed by incubation with serum from SCIT and non-SCIT patients, Der-p allergen, and PBMCs. Levels of interleukin (IL)-4, IL-5, IL-10, IL-13, IL-17, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β1 were evaluated in supernatant. ResultsWe found that SCIT patients had significantly lower SMS after week 52. Der-p sIgG4 levels in SCIT patients significantly increased at week 16 compared with non-SCIT subjects. CD4+IL-4+IFN-γ− Th2% in SCIT patients showed a significant decrease from weeks 104–156 compared with week 0, while no change was observed in CD4+CD25+Foxp3+ Treg and CD4+IL-4−IFN-γ+ Th1 percentages. IL-5, IL-13, IL-4, IL-17, and TNF-α levels in supernatant of PBMCs cultured with serum of SCIT patients after 16 weeks showed significant lower levels compared with non-SCIT patients, and showed significant reverse associations with Der-p sIgG4 levels. ConclusionSCIT induced Dep-p sIgG4 may be involved in downregulating Th2 cytokine production in Der-p allergic asthma patients.

Механизмы взаимодействия мелатонина c лимфоцитами

Melatonin is an indoleamine synthesized from the essential amino acid tryptophan. At the system level, it is produced mainly by the pineal gland, and at the local level, by most organs and tissues, including the gastrointestinal tract, liver, kidneys, lungs, skin, tissues of the reproductive system, and many others. The hormone regulates a wide range of biological reactions in health and diseases, and has a pronounced antioxidant, anti-inflammatory and antitumor activity. Along with this, melatonin is an effective regulator of the immune system, however, the data available to date on the problem are extremely contradictory, especially for the main effectors of adaptive immunity - T-lymphocytes. On the one hand, under physiological conditions or under immunodeficiency conditions, the effects of melatonin are usually stimulatory: it enhances the proliferative response of T- and B-lymphocytes, increases the production of Th1-cytokines, and inhibits apoptosis of lymphocytes induced by various stimuli. On the other hand, there are no fewer works demonstrating the immunosuppressive activity of melatonin, in particular, suppression of the production of pro-inflammatory cytokines. The resolution of these contradictions is the goal of this review. At the same time, the work focuses on two fundamental points. First, the main part of immunostimulating effects was obtained in experiments in vitro, while immunosuppressive effects were obtained in vivo, and since melatonin controls the synthesis of a number of other hormones of the hypothalamic-pituitary-adrenal and / or gonadal axes, many of which are effective immunomodulators themselves, it direct effects in vivo can be mediated and offset by other hormones. Second, lymphocytes express three high-affinity melatonin receptors: two membrane receptors, MT1 and MT2, and a nuclear one, RORα, as well as a number of low-specific targets, all with varying affinities for melatonin. Binding of different receptors apparently triggers different signaling mechanisms. Accordingly, physiological, pathological and pharmacological concentrations of melatonin can have different immunomodulating effects, and when evaluating the effect of melatonin on the immune system, it is important to correlate the hormone concentrations with the state of the receptor apparatus of the cells under study.

Differential Activity of Human Leukocyte Extract on Systemic Immune Response and Cyst Growth in Mice with Echinococcus Multilocularis Infection After Oral, Subcutaneous and Intraperitoneal Routes of Administration.

Alveolar echinococcosis (AE) caused by the larval stage of Echinococcus multilocularis is serious parasitic diseases associated with the host´s immunosuppression. The effects of human non-immune dialyzable leukocyte extract (DLE) on immune cells in blood and spleen and parasitic cysts weight in Balb/c mice after oral (PO), subcutaneous (SC) and intraperitoneal administration (IP) were compared. The reduction in cysts weight (p < 0.01) was recorded after PO route, whereas moderate reduction was found after SC and IP routes. The elevation of lymphoid populations in blood and spleen was found after PO administration (p < 0.01) in parallel with reduced myeloid population. Infection-elicited decline in B220+B cells was partially abolished by PO route, but DLE routes did not influence the CD3+ T cells. The proportions of CD3+CD4+Th lymphocytes were moderately upregulated, whereas CD3+CD8+Tc populations were reduced after all DLE routes (p < 0.01). PO administration increased CD11b+MHCIIhigh blood monocytes, CD11b-SigleF+ cell, but not CD11b+Si-glecF+ eosinophils in the blood, stimulated after SC and IP routes. DLE induced downregulation of NO production by LPS-stimulated adherent splenocytes ex vivo. Con A-triggered T lymphocyte proliferation was associated with the elevated IFN-γ production and transcription factor Tbet mRNA expression. The alleviation of Th2 (IL-4) and Treg (TGF-β) cytokine production by lymphocytes ex vivo paralleled with downregulation of gene transcription for cytokines, GATA and FoxP3. Reduction of myeloid cells with suppressive activity was found. The SC and IP routes affected partially the cysts weights, diminished significantly gene transcription, NO levels and Th2 and Treg cytokines production. Results showed that PO route of DLE administration was the most effective in ameliorating immunosuppression via stimulation of Th1 type, reducing Th2 and Treg type of immunity and CD3+CD8+Tc lymphocytes in the blood and spleens during E. multilocularis infection in mice.

Computational analysis to define efficacy & molecular mechanisms of 7, 4'- Dihydroxyflavone on eosinophilic esophagitis: Ex-vivo validation in human esophagus biopsies.

Eosinophilic Esophagitis (EoE) is a chronic condition characterized by eosinophilic inflammation of the esophagus which leads to esophageal dysfunction with common symptoms including vomiting, feeding difficulty, dysphagia, abdominal pain. Current main treatment options of EoE include dietary elimination and swallowed steroids. Diet elimination approach could lead to identifying the trigger food(s), but it often requires repeated upper endoscopy with general anesthesia and potentially could negatively affect nutrition intake and growth of the child and individuals' quality of life. Although the swallowed steroid treatment of effective, the EoE will universally recur after discontinuation of the treatment. Digestive Tea formula (DTF) has been used by the Traditional Chinese Medicine (TCM) practice to improve GI symptoms in EoE patients, including abdominal pain, GE reflux, and abnormal bowel movement. Previously, a flavonoid small molecule compound 7, 4 dihydroxy flavone (DHF) from Glycyrrhiza uralensis in DTF inhibited eotaxin, Th2 cytokine and IgE production in vitro and in vivo. This study comprehensively evaluates the potential therapeutic and immunological mechanisms underlying DHF improvement of symptoms related to EoE using computational modeling, including target mining, gene ontology enrichment, pathway analyses, protein-protein interaction analyses, in silico molecular docking and dynamic simulation followed by ex-vivo target validation by qRT-PCR using cultured human esophagus biopsy specimen with or without DHF from patients with EoE. Computational analyses defined 29 common targets of DHF on EoE, among which TNF-α, IL-6, IL1β, MAPK1, MAPK3 and AKT1 were most important. Docking analysis and dynamic simulation revealed that DHF directly binds TNF-α with a free binding energy of -7.7 kcal/mol with greater stability and flexibility. Subsequently, in the human esophagus biopsy culture system, significant reduction in levels of TNF-α, IL-6, IL-8 and IL1-β was found in the supernatant of biopsy sample cultured with DHF. Furthermore, the gene expression profile showed significant reduction in levels of TNF-α, IL1-β, IL-6, CCND and MAPK1 in the esophagus biopsy sample cultured with DHF. Taken together, the current study provides us an insight into the molecular mechanisms underlying multi-targeted benefits of DHF in the treatment of EoE and paves the way for facilitating more effective EoE therapies.

Immunomodulatory Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Allergic Airway Disease.

Mesenchymal stem cells (MSCs) have been reported as promising candidates for the treatment of various diseases, especially allergic diseases, as they have the capacity to differentiate into various cells. However, MSCs itself have several limitations such as creating a risk of aneuploidy, difficulty in handling them, immune rejection, and tumorigenicity, so interest in the extracellular vesicles (EVs) released from MSCs are increasing, and many studies have been reported. Previous studies have shown that extracellular vesicles (EVs) produced by MSCs are as effective as the MSCs themselves in suppression of allergic airway inflammation through the suppression of Th2 cytokine production and the induction of regulatory T cells (Treg) expansion. EVs are one of the substances secreted by paracrine induction from MSCs, and because it exerts its effect by delivering contents such as mRNA, microRNA, and proteins to the receptor cell, it can reduce the problems or risks related to stem cell therapy. This article reviews the immunomodulatory properties of MSCs-derived EVs and their therapeutic implications for allergic airway disease.

462 Gametocyte Specific Factor 1 contributes to the Th phenotype in Cutaneous T-Cell Lymphomas

Ectopic expression of Gametocyte Specific Factor 1 (GTSF1) in Cutaneous T-Cell Lymphoma (CTCL) patients has been reported by several groups. Moreover, it has been associated with a worse prognosis and late-stage CTCL. GTSF1 is a gamete gene that participates in the piRNA pathway to silence retrotransposons on the genome. Despite the established association with a worse prognosis the molecular function of GTSF1 expression remains unknown. Therefore, we established shRNA-mediated GTSF1 knockdown CTCL cell lines. Using qRT-PCR, Western blot and a retrotransposition assay, we demonstrated that GTSF1 knockdown does not lead to mobilization of the retrotransposon LINE-1. These data suggest GTSF1 has a novel role in CTCL. Interestingly, after GTSF1 knockdown in the Mac2A cell line, we observed striking growth inhibition, suggesting this gene is a key player in CTCL carcinogenesis. To further explore this role, we performed RNA-Seq, comparing GTSF1 knockdown to control cells. Differential gene expression analysis using DESeq2, revealed 12496 differentially expressed genes (p adjusted <0.05). Pathway enrichment analysis was performed via GO, KEGG, Reactome and WikiPathways. We observed an enrichment of several pathways including response to stimulus, immune response, response to cytokine and inflammatory response. More specifically, transcriptome analysis showed an increased expression of cytokine induced genes, such as XAF1, IFI27 and IFI44L, and genes associated with a Th1 phenotype, IFNG and TNF. Research shows that CTCL progression leads to defects in Th1 cytokine production (IFN-γ and TNF-α) by antitumor immune cells and an enhanced Th2 cytokine production (IL-4 and IL-5) by malignant T cells. The chronic production of Th2 cytokines by malignant cells leads to immune deficiency in patients, allowing malignant cells to proliferate and the disease to progress. Taken together, these data suggest GTSF1 as a novel regulator of the Th phenotype on CTCL, thereby placing it as a potential treatment target for regulating disease progression.

Suppression of T-Cell Proliferation by Normal Density Granulocytes Led to CD183 Downregulation and Cytokine Inhibition in T-Cells.

Normal density granulocytes (NDGs) can suppress T-cell responses in a similar way as myeloid-derived suppressor cells (MDSCs). In this study, we tested the hypothesis that NDGs from healthy donors preferentially inhibit T helper 1 (Th1) cells and investigated the myeloid-derived suppressive effect in different T-cell populations. We found that NDG-induced suppression of T-cell proliferation was contact dependent, mediated by integrin CD11b, and dependent on NDG-production of reactive oxygen species (ROS). The suppression was rapid and occurred within the first few hours of coculture. The suppression did not influence the CD8+/CD4+ ratio indicating an equal sensitivity in these populations. We further analyzed the CD4+ T helper subsets and found that NDGs induced a loss of Th1 surface marker, CD183, that was unrelated to ligand-binding to CD183. In addition, we analyzed the Th1, Th2, and Th17 cytokine production and found that all cytokine groups were suppressed when T-cells were incubated with NDGs. We therefore concluded that NDGs do not preferentially suppress Th1-cells. Instead, NDGs generally suppress Th cells and cytotoxic T-cells but specifically downregulate the Th1 marker CD183.

Association between SARS-CoV-2 RNAemia and dysregulated immune response in acutely ill hospitalized COVID-19 patients

Severe/critical COVID-19 is associated with immune dysregulation and plasmatic SARS-CoV-2 detection (i.e. RNAemia). We detailed the association of SARS-CoV-2 RNAemia with immune responses in COVID-19 patients at the end of the first week of disease. We enrolled patients hospitalized in acute phase of ascertained SARS-CoV-2 pneumonia, and evaluated SARS-CoV-2 RNAemia, plasmatic cytokines, activated/pro-cytolytic T-cells phenotypes, SARS-CoV-2-specific cytokine-producing T-cells (IL-2, IFN-γ, TNF-α, IL-4, IL-17A), simultaneous Th1-cytokines production (polyfunctionality) and amount (iMFI). The humoral responses were assessed with anti-S1/S2 IgG, anti-RBD total-Ig, IgM, IgA, IgG1 and IgG3, neutralization and antibody-dependent cellular cytotoxicity (ADCC). Out of 54 patients, 27 had detectable viremia (viremic). Albeit comparable age and co-morbidities, viremic more frequently required ventilatory support, with a trend to higher death. Viremic displayed higher pro-inflammatory cytokines (IFN-α, IL-6), lower activated T-cells (HLA-DR+CD38+), lower functional SARS-CoV-2-specific T-cells (IFN-γ+CD4+, TNF-α+CD8+, IL-4+CD8+, IL-2+TNF-α+CD4+, and IL-2+TNF-α+CD4+ iMFI) and SARS-CoV-2-specific Abs (anti-S IgG, anti-RBD total-Ig, IgM, IgG1, IgG3; ID50, %ADCC). These data suggest a link between SARS-CoV-2 RNAemia at the end of the first stage of disease and immune dysregulation. Whether high ab initium viral burden and/or intrinsic host factors contribute to immune dysregulation in severe COVID-19 remains to be elucidated, to further inform strategies of targeted therapeutic interventions.