IL-9-producing T cells: potential players in allergy and cancer

Bevacizumab induces ferroptosis and enhances CD8+ T cell immune activity in liver cancer via modulating HAT1 and increasing IL-9

Bevacizumab is a recombinant humanized monoclonal immunoglobulin (Ig) G1 antibody of VEGF, and inhibits angiogenesis and tumor growth in hepatocellular carcinoma (HCC). Ferroptosis, a new form of regulated cell death function independently of the apoptotic machinery, has been accepted as an attractive target for pharmacological intervention; the ferroptosis pathway can enhance cell immune activity of anti-PD1 immunotherapy in HCC. In this study we investigated whether and how bevacizumab regulated ferroptosis and immune activity in liver cancer. Firstly, we performed RNA-sequencing in bevacizumab-treated human liver cancer cell line HepG2 cells, and found that bevacizumab significantly altered the expression of a number of genes including VEGF, PI3K, HAT1, SLC7A11 and IL-9 in liver cancer, bevacizumab upregulated 37 ferroptosis-related drivers, and downregulated 17 ferroptosis-related suppressors in particular. We demonstrated that bevacizumab triggered ferroptosis in liver cancer cells by driving VEGF/PI3K/HAT1/SLC7A11 axis. Clinical data confirmed that the expression levels of VEGF were positively associated with those of PI3K, HAT1 and SLC7A11 in HCC tissues. Meanwhile, we found that bevacizumab enhanced immune cell activity in tumor immune-microenvironment. We identified that HAT1 up-regulated miR-143 targeting IL-9 mRNA 3'UTR in liver cancer cells; bevacizumab treatment resulted in the increase of IL-9 levels and its secretion via VEGF/PI3K/HAT1/miR-143/IL-9 axis, which led to the inhibition of tumor growth in vivo through increasing the release of IL-2 and Granzyme B from activated CD8+ T cells. We conclude that in addition to inhibiting angiogenesis, bevacizumab induces ferroptosis and enhances CD8+ T cell immune activity in liver cancer. This study provides new insight into the mechanisms by which bevacizumab synergistically modulates ferroptosis and CD8+ T cell immune activity in liver cancer.

The role of serum interleukins in Cancer: A Multi-center Mendelian Randomization study

The occurrence of cancer is often accompanied by immune evasion and tumor-promoting inflammation, with interleukins (IL) playing a pivotal role in the immune-inflammatory mechanism. However, the precise contribution of serum interleukins in cancer remains elusive. We obtained GWAS summary data for 35 interleukins from eight independent large-scale serum proteome studies of European ancestry populations and for 23 common cancers from the FinnGen Consortium. We then conducted a multicenter Mendelian Randomization (MR) study to explore the relationship between systemic inflammatory status and cancers. 24 causal associations between interleukins and cancers were supported by multicenter data, 18 of which were reported for the first time. Our results indicated that IL-1α (Hodgkin lymphoma), IL-5 (bladder cancer), IL-7 (prostate cancer), IL-11 (bone malignant tumor), IL-16 (lung cancer), IL-17A (pancreatic cancer), IL-20 (bladder cancer), IL-22 (lymphocytic leukemia), IL-34 (breast cancer), IL-36β (prostate cancer), and IL-36γ (liver cancer) were risk factors for related cancers. Conversely, IL-9 (malignant neoplasms of the corpus uteri), IL-17C (liver cancer), and IL-31 (colorectal cancer, bladder cancer, pancreatic cancer, and cutaneous melanoma) exhibited protective effects against related cancers. Notably, the dual effects of serum interleukins were also observed. IL-18 acted as a risk factor for prostate cancer, however, was a protective factor against laryngeal cancer. Similarly, IL-19 promoted the development of lung cancer and myeloid leukemia, while conferring protection against Breast, cervical, and thyroid cancers. Our study confirmed the genetic association between multiple serum interleukins and cancers. Immune and anti-inflammatory strategies targeting these associations provide opportunities for prevention and treatment.

Insights into the clinical, immunologic, and genetic underpinnings of food allergy

The last few decades have seen striking changes in the field of food allergy. The prevalence of the disease has risen dramatically in many parts of the globe, and management of the condition has undergone major revision. While delayed introduction of common allergenic foods during infancy was advised for many years, the learning early about peanut allergy (LEAP) trial and other studies led to a major shift in infant feeding practices, with deliberate early introduction of these foods now recommended. Additionally, the Food and Drug Administration approved the first treatment for food allergy in 2020-a peanut oral immunotherapy (OIT) product that likely represents just the beginning of new immunotherapy-based and other treatments for food allergy. Our knowledge of the environmental and genetic factors contributing to the pathogenesis of food allergy has also undergone transformational advances. Here, we will discuss our efforts to improve the clinical care of patients with food allergy and our understanding of the immunological mechanisms contributing to this common disease.

Evolution of pathologic B-cell subsets and serum environment-specific sIgEs in patients with atopic dermatitis and controls, from infancy to adulthood

BACKGROUND

While B-cells have historically been implicated in allergy development, a growing body of evidence supports their role in atopic dermatitis (AD). B-cell differentiation across ages in AD, and its relation to disease severity scores, has not been well defined.

OBJECTIVE

To compare the frequency of B-cell subsets in blood of 0-5, 6-11, 12-17, and ≥18 years old patients with AD versus age-matched controls.

METHODS

Flow cytometry was used to measure B-cell subset frequencies in the blood of 27 infants, 17 children, 11 adolescents, and 31 adults with moderate-to-severe AD and age-matched controls. IgD/CD27 and CD24/CD38 core gating systems and an 11-color flow cytometry panel were used to determine frequencies of circulating B-cell subsets. Serum total and allergen-specific IgE (sIgEs) levels were measured using ImmunoCAP®.

RESULTS

Adolescents with AD had lower frequencies of major B-cells subsets (p < .03). CD23 expression increased with age and was higher in AD compared to controls across all age groups (p < .04). In AD patients, multiple positive correlations were observed between IL-17-producing T-cells and B-cell subsets, most significantly non-switched memory (NSM) B-cells (r = .41, p = .0005). AD severity positively correlated with a list of B-cell subsets (p < .05). IL-9 levels gradually increased during childhood, reaching a peak in adolescence, paralleling allergen sensitization, particularly in severe AD. Principal component analysis of the aggregated environmental sIgE data showed that while controls across all ages tightly clustered together, adolescents with AD demonstrated distinct clustering patterns relative to controls.

CONCLUSIONS

Multiple correlations between B-cells and T-cells, as well as disease severity measures, suggest a complex interplay of immune pathways in AD. Unique B-cell signature during adolescence, with concurrent allergen sensitization and IL-9 surge, point to a potentially wider window of opportunity to implement interventions that may prevent the progression of the atopic march.

The emerging role of T helper 9 (Th9) cells in immunopathophysiology: A comprehensive review of their effects and responsiveness in various disease states

Th9 cells, a subset of T-helper cells producing interleukin-9 (IL-9), play a vital role in the adaptive immune response and have diverse effects in different diseases. Regulated by transcription factors like PU.1 and IRF4, and cytokines such as IL-4 and TGF-β, Th9 cells drive tissue inflammation. This review focuses on their emerging role in immunopathophysiology. Th9 cells exhibit immune-mediated cancer cell destruction, showing promise in glioma and cervical cancer treatment. However, their role in breast and lung cancer is intricate, requiring a deeper understanding of pro- and anti-tumor aspects. Th9 cells, along with IL-9, foster T cell and immune cell proliferation, contributing to autoimmune disorders. They are implicated in psoriasis, atopic dermatitis, and infections. In allergic reactions and asthma, Th9 cells fuel pro-inflammatory responses. Targeting Foxo1 may regulate innate and adaptive immune responses, alleviating disease symptoms. This comprehensive review outlines Th9 cells' evolving immunopathophysiological role, emphasizing the necessity for further research to grasp their effects and potential therapeutic applications across diseases.

Allergen-Encapsulating Nanoparticles Reprogram Pathogenic Allergen-Specific Th2 Cells to Suppress Food Allergy

Food allergy is a prevalent, potentially deadly disease caused by inadvertent sensitization to benign food antigens. Pathogenic Th2 cells are a major driver for disease, and allergen-specific immunotherapies (AIT) aim to increase the allergen threshold required to elicit severe allergic symptoms. However, the majority of AIT approaches require lengthy treatments and convey transient disease suppression, likely due to insufficient targeting of pathogenic Th2 responses. Here, the ability of allergen-encapsulating nanoparticles to directly suppress pathogenic Th2 responses and reactivity is investigated in a mouse model of food allergy. NPs associate with pro-tolerogenic antigen presenting cells, provoking accumulation of antigen-specific, functionally suppressive regulatory T cells in the small intestine lamina propria. Two intravenous doses of allergen encapsulated in poly(lactide-co-glycolide) nanoparticles (NPs) significantly reduces oral food challenge (OFC)-induced anaphylaxis. Importantly, NP treatment alters the fates of pathogenic allergen-specific Th2 cells, reprogramming these cells toward CD25+FoxP3+ regulatory and CD73+FR4+ anergic phenotypes. NP-mediated reductions in the frequency of effector cells in the gut and mast cell degranulation following OFC are also demonstrated. These studies reveal mechanisms by which an allergen-encapsulating NP therapy and, more broadly, allergen-specific immunotherapies, can rapidly attenuate allergic responses by targeting pathogenic Th2 cells.

Oleic acid triggers metabolic rewiring of T cells poising them for T helper 9 differentiation

T cells are the most common immune cells in atherosclerotic plaques, and the function of T cells can be altered by fatty acids. Here, we show that pre-exposure of CD4+ T cells to oleic acid, an abundant fatty acid linked to cardiovascular events, upregulates core metabolic pathways and promotes differentiation into interleukin-9 (IL-9)-producing cells upon activation. RNA sequencing of non-activated T cells reveals that oleic acid upregulates genes encoding key enzymes responsible for cholesterol and fatty acid biosynthesis. Transcription footprint analysis links these expression changes to the differentiation toward TH9 cells, a pro-atherogenic subset. Spectral flow cytometry shows that pre-exposure to oleic acid results in a skew toward IL-9+-producing T cells upon activation. Importantly, pharmacological inhibition of either cholesterol or fatty acid biosynthesis abolishes this effect, suggesting a beneficial role for statins beyond cholesterol lowering. Taken together, oleic acid may affect inflammatory diseases like atherosclerosis by rewiring T cell metabolism.

Integration of CD4+ T cells and molecular subtype predicts benefit from PD-L1 blockade in muscle-invasive bladder cancer

Muscle-invasive bladder cancer (MIBC) is a disease characterized by molecular and clinical heterogeneity, posing challenges in selecting the most appropriate treatment in clinical settings. Considering the significant role of CD4+ T cells, there is an emerging need to integrate CD4+ T cells with molecular subtypes to refine classification. We conducted a comprehensive study involving 895 MIBC patients from four independent cohorts. The Zhongshan Hospital (ZSHS) and The Cancer Genome Atlas (TCGA) cohorts were included to investigate chemotherapeutic response. The IMvigor210 cohort was included to assess the immunotherapeutic response. NCT03179943 was used to evaluate the clinical response to a combination of immune checkpoint blockade (ICB) and chemotherapy. Additionally, we evaluated genomic characteristics and the immune microenvironment to gain deeper insights into the distinctive features of each subtype. We unveiled four immune-molecular subtypes, each exhibiting distinct clinical outcomes and molecular characteristics. These subtypes include luminal CD4+ Thigh, which demonstrated benefits from both immunotherapy and chemotherapy; luminal CD4+ Tlow, characterized by the highest level of fibroblast growth factor receptor 3 (FGFR3) mutation, thus indicating potential responsiveness to FGFR inhibitors; basal CD4+ Thigh, which could benefit from a combination of ICB and chemotherapy; and basal CD4+ Tlow, characterized by an immune suppression microenvironment and likely to benefit from transforming growth factor-β (TGF-β) inhibition. This immune-molecular classification offers new possibilities for optimizing therapeutic interventions in MIBC.

Smith-specific regulatory T cells halt the progression of lupus nephritis

Antigen-specific regulatory T cells (Tregs) suppress pathogenic autoreactivity and are potential therapeutic candidates for autoimmune diseases such as systemic lupus erythematosus (SLE). Lupus nephritis is associated with autoreactivity to the Smith (Sm) autoantigen and the human leucocyte antigen (HLA)-DR15 haplotype; hence, we investigated the potential of Sm-specific Tregs (Sm-Tregs) to suppress disease. Here we identify a HLA-DR15 restricted immunodominant Sm T cell epitope using biophysical affinity binding assays, then identify high-affinity Sm-specific T cell receptors (TCRs) using high-throughput single-cell sequencing. Using lentiviral vectors, we transduce our lead Sm-specific TCR into Tregs derived from patients with SLE who are anti-Sm and HLA-DR15 positive. Compared with polyclonal mock-transduced Tregs, Sm-Tregs potently suppress Sm-specific pro-inflammatory responses in vitro and suppress disease progression in a humanized mouse model of lupus nephritis. These results show that Sm-Tregs are a promising therapy for SLE.

Inhibition of T-cell activity in alopecia areata: recent developments and new directions

Alopecia areata (AA) is an autoimmune disease that has a complex underlying immunopathogenesis characterized by nonscarring hair loss ranging from small bald patches to complete loss of scalp, face, and/or body hair. Although the etiopathogenesis of AA has not yet been fully characterized, immune privilege collapse at the hair follicle (HF) followed by T-cell receptor recognition of exposed HF autoantigens by autoreactive cytotoxic CD8+ T cells is now understood to play a central role. Few treatment options are available, with the Janus kinase (JAK) 1/2 inhibitor baricitinib (2022) and the selective JAK3/tyrosine kinase expressed in hepatocellular carcinoma (TEC) inhibitor ritlecitinib (2023) being the only US Food and Drug Administration-approved systemic medications thus far for severe AA. Several other treatments are used off-label with limited efficacy and/or suboptimal safety and tolerability. With an increased understanding of the T-cell-mediated autoimmune and inflammatory pathogenesis of AA, additional therapeutic pathways beyond JAK inhibition are currently under investigation for the development of AA therapies. This narrative review presents a detailed overview about the role of T cells and T-cell-signaling pathways in the pathogenesis of AA, with a focus on those pathways targeted by drugs in clinical development for the treatment of AA. A detailed summary of new drugs targeting these pathways with expert commentary on future directions for AA drug development and the importance of targeting multiple T-cell-signaling pathways is also provided in this review.

DUSP8 induces TGF-β-stimulated IL-9 transcription and Th9-mediated allergic inflammation by promoting nuclear export of Pur-α

Dual-specificity phosphatase 8 (DUSP8) is a MAPK phosphatase that dephosphorylates and inactivates the kinase JNK. DUSP8 is highly expressed in T cells; however, the in vivo role of DUSP8 in T cells remains unclear. Using T cell-specific Dusp8 conditional KO (T-Dusp8 cKO) mice, mass spectrometry analysis, ChIP-Seq, and immune analysis, we found that DUSP8 interacted with Pur-α, stimulated interleukin-9 (IL-9) gene expression, and promoted Th9 differentiation. Mechanistically, DUSP8 dephosphorylated the transcriptional repressor Pur-α upon TGF-β signaling, leading to the nuclear export of Pur-α and subsequent IL-9 transcriptional activation. Furthermore, Il-9 mRNA levels were induced in Pur-α-deficient T cells. In addition, T-Dusp8-cKO mice displayed reduction of IL-9 and Th9-mediated immune responses in the allergic asthma model. Reduction of Il-9 mRNA levels in T cells and allergic responses of T-Dusp8-cKO mice was reversed by Pur-α knockout. Remarkably, DUSP8 protein levels and the DUSP8-Pur-α interaction were indeed increased in the cytoplasm of T cells from people with asthma and patients with atopic dermatitis. Collectively, DUSP8 induces TGF-β-stimulated IL-9 transcription and Th9-induced allergic responses by inhibiting the nuclear translocation of the transcriptional repressor Pur-α. DUSP8 may be a T-cell biomarker and therapeutic target for asthma and atopic dermatitis.

Innate lymphoid cells: a new key player in atopic dermatitis

Atopic dermatitis (AD) is a common allergic inflammatory skin condition mainly caused by gene variants, immune disorders, and environmental risk factors. The T helper (Th) 2 immune response mediated by interleukin (IL)-4/13 is generally believed to be central in the pathogenesis of AD. It has been shown that innate lymphoid cells (ILCs) play a major effector cell role in the immune response in tissue homeostasis and inflammation and fascinating details about the interaction between innate and adaptive immunity. Changes in ILCs may contribute to the onset and progression of AD, and ILC2s especially have gained much attention. However, the role of ILCs in AD still needs to be further elucidated. This review summarizes the role of ILCs in skin homeostasis and highlights the signaling pathways in which ILCs may be involved in AD, thus providing valuable insights into the behavior of ILCs in skin homeostasis and inflammation, as well as new approaches to treating AD.

A blunted TH17 cytokine signature in women with mild cognitive impairment: insights from inflammatory profiling of a community-based cohort of older adults

People with dementia have an increase in brain inflammation, caused in part by innate and adaptive immune cells. However, it remains unknown whether dementia-associated diseases alter neuro-immune reflex arcs to impact the systemic immune system. We examined peripheral immune cells from a community-based cohort of older adults to test if systemic inflammatory cytokine signatures associated with early stages of cognitive impairment. Human peripheral blood mononuclear cells were cultured with monocyte or T-cell-targeted stimuli, and multiplex assays quantitated cytokines in the conditioned media. Following T-cell-targeted stimulation, cells from women with cognitive impairment produced lower amounts of TH17 cytokines compared with cells from cognitively healthy women, while myeloid-targeted stimuli elicited similar amounts of cytokines from cells of both groups. This TH17 signature correlated with the proportion of circulating CD4+ and CD8+ T cells and plasma glial fibrillary acidic protein and neurofilament light concentrations. These results suggest that decreases in TH17 cytokines could be an early systemic change in women at risk for developing dementia. Amelioration of TH17s cytokines in early cognitive impairment could, in part, explain the compromised ability of older adults to respond to vaccines or defend against infection.

Differential response of HBV envelope-specific CD4 + T cells is related to HBsAg loss after stopping nucleos(t)ide analogue therapy

BACKGROUND AND AIM

Long-term maintenance of viral control, even HBsAg loss, remains a challenge for chronic hepatitis B (CHB) patients undergoing nucleos(t)ide analogue (NA) discontinuation. This study aimed to investigate the relationship between HBV-specific T-cell responses targeting peptides spanning the whole proteome and clinical outcomes in CHB patients after NA discontinuation.

APPROACH AND RESULTS

Eighty-eight CHB patients undergoing NA discontinuation were classified as responders (remained relapse-free up to 96 weeks) or relapsers (relapsed patients who underwent NA retreatment for up to 48 weeks and reachieved stable viral control). HBV-specific T-cell responses were detected at baseline and longitudinally throughout the follow-up. We found responders had a greater magnitude of HBV polymerase (Pol)-specific T-cell responses than relapsers at baseline. After long-term NA discontinuation, simultaneously enhanced HBV Core-induced and Pol-induced responses were observed in responders. Particularly, responders with HBsAg loss possessed enhanced HBV Envelope (Env)-induced responses after short-term and long-term follow-up. Notably, CD4 + T cells accounted for the predominance of HBV-specific T-cell responses. Correspondingly, CD4-deficient mice showed attenuated HBV-specific CD8 + T-cell responses, reduced HBsAb-producing B cells, and delayed HBsAg loss; in contrast, in vitro addition of CD4 + T cells promoted HBsAb production by B cells. Besides, IL-9, rather than PD-1 blockade, enhanced HBV Pol-specific CD4 + T-cell responses.

CONCLUSION

HBV-specific CD4 + T-cell responses induced by the targeted peptide possess specificities for long-term viral control and HBsAg loss in CHB patients undergoing NA discontinuation, indicating that CD4 + T cells specific to distinct HBV antigens may endow with divergent antiviral potential.

The interweaved signatures of common-gamma-chain cytokines across immunologic lineages

"γc" cytokines are a family whose receptors share a "common-gamma-chain" signaling moiety, and play central roles in differentiation, homeostasis, and communications of all immunocyte lineages. As a resource to better understand their range and specificity of action, we profiled by RNAseq the immediate-early responses to the main γc cytokines across all immunocyte lineages. The results reveal an unprecedented landscape: broader, with extensive overlap between cytokines (one cytokine doing in one cell what another does elsewhere) and essentially no effects unique to any one cytokine. Responses include a major downregulation component and a broad Myc-controlled resetting of biosynthetic and metabolic pathways. Various mechanisms appear involved: fast transcriptional activation, chromatin remodeling, and mRNA destabilization. Other surprises were uncovered: IL2 effects in mast cells, shifts between follicular and marginal zone B cells, paradoxical and cell-specific cross-talk between interferon and γc signatures, or an NKT-like program induced by IL21 in CD8+ T cells.

Inflammatory factors and risk of meningiomas: a bidirectional mendelian-randomization study

Background

Meningiomas are one of the most common intracranial tumors, and the current understanding of meningioma pathology is still incomplete. Inflammatory factors play an important role in the pathophysiology of meningioma, but the causal relationship between inflammatory factors and meningioma is still unclear.

Method

Mendelian randomization (MR) is an effective statistical method for reducing bias based on whole genome sequencing data. It's a simple but powerful framework, that uses genetics to study aspects of human biology. Modern methods of MR make the process more robust by exploiting the many genetic variants that may exist for a given hypothesis. In this paper, MR is applied to understand the causal relationship between exposure and disease outcome.

Results

This research presents a comprehensive MR study to study the association of genetic inflammatory cytokines with meningioma. Based on the results of our MR analysis, which examines 41 cytokines in the largest GWAS datasets available, we were able to draw the relatively more reliable conclusion that elevated levels of circulating TNF-β, CXCL1, and lower levels of IL-9 were suggestive associated with a higher risk of meningioma. Moreover, Meningiomas could cause lower levels of interleukin-16 and higher levels of CXCL10 in the blood.

Conclusion

These findings suggest that TNF-β, CXCL1, and IL-9 play an important role in the development of meningiomas. Meningiomas also affect the expression of cytokines such as IL-16 and CXCL10. Further studies are needed to determine whether these biomarkers can be used to prevent or treat meningiomas.

T cells in health and disease

T cells are crucial for immune functions to maintain health and prevent disease. T cell development occurs in a stepwise process in the thymus and mainly generates CD4⁺ and CD8⁺ T cell subsets. Upon antigen stimulation, naïve T cells differentiate into CD4⁺ helper and CD8⁺ cytotoxic effector and memory cells, mediating direct killing, diverse immune regulatory function, and long-term protection. In response to acute and chronic infections and tumors, T cells adopt distinct differentiation trajectories and develop into a range of heterogeneous populations with various phenotype, differentiation potential, and functionality under precise and elaborate regulations of transcriptional and epigenetic programs. Abnormal T-cell immunity can initiate and promote the pathogenesis of autoimmune diseases. In this review, we summarize the current understanding of T cell development, CD4⁺ and CD8⁺ T cell classification, and differentiation in physiological settings. We further elaborate the heterogeneity, differentiation, functionality, and regulation network of CD4⁺ and CD8⁺ T cells in infectious disease, chronic infection and tumor, and autoimmune disease, highlighting the exhausted CD8⁺ T cell differentiation trajectory, CD4⁺ T cell helper function, T cell contributions to immunotherapy and autoimmune pathogenesis. We also discuss the development and function of γδ T cells in tissue surveillance, infection, and tumor immunity. Finally, we summarized current T-cell-based immunotherapies in both cancer and autoimmune diseases, with an emphasis on their clinical applications. A better understanding of T cell immunity provides insight into developing novel prophylactic and therapeutic strategies in human diseases.

Mechanistic and Therapeutic Approaches to Occupational Exposure-Associated Allergic and Non-Allergic Asthmatic Disease

PURPOSE OF REVIEW

Occupational lung disease, including asthma, is a significant cause of disability worldwide. The dose, exposure frequency, and nature of the causal agent influence the inflammatory pathomechanisms that inform asthma disease phenotype and progression. While surveillance, systems engineering, and exposure mitigation strategies are essential preventative considerations, no targeted medical therapies are currently available to ameliorate lung injury post-exposure and prevent chronic airway disease development.

RECENT FINDINGS

This article reviews contemporary understanding of allergic and non-allergic occupational asthma mechanisms. In addition, we discuss the available therapeutic options, patient-specific susceptibility and prevention measures, and recent scientific advances in post-exposure treatment conception. The course of occupational lung disease that follows exposure is informed by individual predisposition, immunobiologic response, agent identity, overall environmental risk, and preventative workplace practices. When protective strategies fail, knowledge of underlying disease mechanisms is necessary to inform targeted therapy development to lessen occupational asthma disease severity and occurrence.

The Dichotomy of Interleukin-9 Function in the Tumor Microenvironment

Interleukin 9 (IL-9) is a cytokine with potent proinflammatory properties that plays a central role in pathologies such as allergic asthma, immunity to parasitic infection, and autoimmunity. More recently, IL-9 has garnered considerable attention in tumor immunity. Historically, IL-9 has been associated with a protumor function in hematological malignancies and an antitumor function in solid malignancies. However, recent discoveries of the dynamic role of IL-9 in cancer progression suggest that IL-9 can act as both a pro- or antitumor factor in various hematological and solid malignancies. This review summarizes IL-9-dependent control of tumor growth, regulation, and therapeutic applicability of IL-9 blockade and IL-9-producing cells in cancer.

Dynamic chromatin accessibility licenses STAT5- and STAT6-dependent innate-like function of TH9 cells to promote allergic inflammation

Allergic diseases are a major global health issue. Interleukin (IL)-9-producing helper T (TH9) cells promote allergic inflammation, yet TH9 cell effector functions are incompletely understood because their lineage instability makes them challenging to study. Here we found that resting TH9 cells produced IL-9 independently of T cell receptor (TCR) restimulation, due to STAT5- and STAT6-dependent bystander activation. This mechanism was seen in circulating cells from allergic patients and was restricted to recently activated cells. STAT5-dependent Il9/IL9 regulatory elements underwent remodeling over time, inactivating the locus. A broader 'allergic TH9' transcriptomic and epigenomic program was also unstable. In vivo, TH9 cells induced airway inflammation via TCR-independent, STAT-dependent mechanisms. In allergic patients, TH9 cell expansion was associated with responsiveness to JAK inhibitors. These findings suggest that TH9 cell instability is a negative checkpoint on bystander activation that breaks down in allergy and that JAK inhibitors should be considered for allergic patients with TH9 cell expansion.

Deep computational image analysis of immune cell niches reveals treatment-specific outcome associations in lung cancer

The tumor immune composition influences prognosis and treatment sensitivity in lung cancer. The presence of effective adaptive immune responses is associated with increased clinical benefit after immune checkpoint blockers. Conversely, immunotherapy resistance can occur as a consequence of local T-cell exhaustion/dysfunction and upregulation of immunosuppressive signals and regulatory cells. Consequently, merely measuring the amount of tumor-infiltrating lymphocytes (TILs) may not accurately reflect the complexity of tumor-immune interactions and T-cell functional states and may not be valuable as a treatment-specific biomarker. In this work, we investigate an immune-related biomarker (PhenoTIL) and its value in associating with treatment-specific outcomes in non-small cell lung cancer (NSCLC). PhenoTIL is a novel computational pathology approach that uses machine learning to capture spatial interplay and infer functional features of immune cell niches associated with tumor rejection and patient outcomes. PhenoTIL's advantage is the computational characterization of the tumor immune microenvironment extracted from H&E-stained preparations. Association with clinical outcome and major non-small cell lung cancer (NSCLC) histology variants was studied in baseline tumor specimens from 1,774 lung cancer patients treated with immunotherapy and/or chemotherapy, including the clinical trial Checkmate 057 (NCT01673867).

Degranulation of Mast Cells as a Target for Drug Development

Mast cells act as key effector cells of inflammatory responses through degranulation. Mast cell degranulation is induced by the activation of cell surface receptors, such as FcεRI, MRGPRX2/B2, and P2RX7. Each receptor, except FcεRI, varies in its expression pattern depending on the tissue, which contributes to their differing involvement in inflammatory responses depending on the site of occurrence. Focusing on the mechanism of allergic inflammatory responses by mast cells, this review will describe newly identified mast cell receptors in terms of their involvement in degranulation induction and patterns of tissue-specific expression. In addition, new drugs targeting mast cell degranulation for the treatment of allergy-related diseases will be introduced.

A human model of asthma exacerbation reveals transcriptional programs and cell circuits specific to allergic asthma

Asthma is a chronic disease most commonly associated with allergy and type 2 inflammation. However, the mechanisms that link airway inflammation to the structural changes that define asthma are incompletely understood. Using a human model of allergen-induced asthma exacerbation, we compared the lower airway mucosa in allergic asthmatics and allergic non-asthmatic controls using single-cell RNA sequencing. In response to allergen, the asthmatic airway epithelium was highly dynamic and up-regulated genes involved in matrix degradation, mucus metaplasia, and glycolysis while failing to induce injury-repair and antioxidant pathways observed in controls. IL9-expressing pathogenic TH2 cells were specific to asthmatic airways and were only observed after allergen challenge. Additionally, conventional type 2 dendritic cells (DC2 that express CD1C) and CCR2-expressing monocyte-derived cells (MCs) were uniquely enriched in asthmatics after allergen, with up-regulation of genes that sustain type 2 inflammation and promote pathologic airway remodeling. In contrast, allergic controls were enriched for macrophage-like MCs that up-regulated tissue repair programs after allergen challenge, suggesting that these populations may protect against asthmatic airway remodeling. Cellular interaction analyses revealed a TH2-mononuclear phagocyte-basal cell interactome unique to asthmatics. These pathogenic cellular circuits were characterized by type 2 programming of immune and structural cells and additional pathways that may sustain and amplify type 2 signals, including TNF family signaling, altered cellular metabolism, failure to engage antioxidant responses, and loss of growth factor signaling. Our findings therefore suggest that pathogenic effector circuits and the absence of proresolution programs drive structural airway disease in response to type 2 inflammation.

PPAR-γ regulates the effector function of human T helper 9 cells by promoting glycolysis

T helper 9 (T_H9) cells promote allergic tissue inflammation and express the type 2 cytokines, IL-9 and IL-13, as well as the transcription factor, PPAR-γ. However, the functional role of PPAR-γ in human T_H9 cells remains unknown. Here, we demonstrate that PPAR-γ drives activation-induced glycolysis, which, in turn, promotes the expression of IL-9, but not IL-13, in an mTORC1-dependent manner. In vitro and ex vivo experiments show that the PPAR-γ-mTORC1-IL-9 pathway is active in T_H9 cells in human skin inflammation. Additionally, we find dynamic regulation of tissue glucose levels in acute allergic skin inflammation, suggesting that in situ glucose availability is linked to distinct immunological functions in vivo. Furthermore, paracrine IL-9 induces expression of the lactate transporter, MCT1, in T_H cells and promotes their aerobic glycolysis and proliferative capacity. Altogether, our findings uncover a hitherto unknown relationship between PPAR-γ-dependent glucose metabolism and pathogenic effector functions in human T_H9 cells.

Interleukins (Cytokines) as Biomarkers in Colorectal Cancer: Progression, Detection, and Monitoring

Cancer is the primary cause of death in economically developed countries and the second leading cause in developing countries. Colorectal cancer (CRC) is the third most common cause of cancer-related deaths worldwide. Risk factors for CRC include obesity, a diet low in fruits and vegetables, physical inactivity, and smoking. CRC has a poor prognosis, and there is a critical need for new diagnostic and prognostic biomarkers to reduce related deaths. Recently, studies have focused more on molecular testing to guide targeted treatments for CRC patients. The most crucial feature of activated immune cells is the production and release of growth factors and cytokines that modulate the inflammatory conditions in tumor tissues. The cytokine network is valuable for the prognosis and pathogenesis of colorectal cancer as they can aid in the cost-effective and non-invasive detection of cancer. A large number of interleukins (IL) released by the immune system at various stages of CRC can act as "biomarkers". They play diverse functions in colorectal cancer, and include IL-4, IL-6, IL-8, IL-11, IL-17A, IL-22, IL-23, IL-33, TNF, TGF-β, and vascular endothelial growth factor (VEGF), which are pro-tumorigenic genes. However, there are an inadequate number of studies in this area considering its correlation with cytokine profiles that are clinically useful in diagnosing cancer. A better understanding of cytokine levels to establish diagnostic pathways entails an understanding of cytokine interactions and the regulation of their various biochemical signaling pathways in healthy individuals. This review provides a comprehensive summary of some interleukins as immunological biomarkers of CRC.

Deficiency of the CD155-CD96 immune checkpoint controls IL-9 production in giant cell arteritis

Loss of function of inhibitory immune checkpoints, unleashing pathogenic immune responses, is a potential risk factor for autoimmune disease. Here, we report that patients with the autoimmune vasculitis giant cell arteritis (GCA) have a defective CD155-CD96 immune checkpoint. Macrophages from patients with GCA retain the checkpoint ligand CD155 in the endoplasmic reticulum (ER) and fail to bring it to the cell surface. CD155^low antigen-presenting cells induce expansion of CD4⁺CD96⁺ T cells, which become tissue invasive, accumulate in the blood vessel wall, and release the effector cytokine interleukin-9 (IL-9). In a humanized mouse model of GCA, recombinant human IL-9 causes vessel wall destruction, whereas anti-IL-9 antibodies efficiently suppress innate and adaptive immunity in the vasculitic lesions. Thus, defective surface translocation of CD155 creates antigen-presenting cells that deviate T cell differentiation toward Th9 lineage commitment and results in the expansion of vasculitogenic effector T cells.

Upregulated Expression of the IL-9 Receptor on TRAF3-Deficient B Lymphocytes Confers Ig Isotype Switching Responsiveness to IL-9 in the Presence of Antigen Receptor Engagement and IL-4

The pleiotropic cytokine IL-9 signals to target cells by binding to a heterodimeric receptor consisting of the unique subunit IL-9R and the common subunit γ-chain shared by multiple cytokines of the γ-chain family. In the current study, we found that the expression of IL-9R was strikingly upregulated in mouse naive follicular B cells genetically deficient in TNFR-associated factor 3 (TRAF3), a critical regulator of B cell survival and function. The highly upregulated IL-9R on Traf3-/- follicular B cells conferred responsiveness to IL-9, including IgM production and STAT3 phosphorylation. Interestingly, IL-9 significantly enhanced class switch recombination to IgG1 induced by BCR crosslinking plus IL-4 in Traf3-/- B cells, which was not observed in littermate control B cells. We further demonstrated that blocking the JAK-STAT3 signaling pathway abrogated the enhancing effect of IL-9 on class switch recombination to IgG1 induced by BCR crosslinking plus IL-4 in Traf3-/- B cells. Our study thus revealed, to our knowledge, a novel pathway that TRAF3 suppresses B cell activation and Ig isotype switching by inhibiting IL-9R-JAK-STAT3 signaling. Taken together, our findings provide (to our knowledge) new insights into the TRAF3-IL-9R axis in B cell function and have significant implications for the understanding and treatment of a variety of human diseases involving aberrant B cell activation such as autoimmune disorders.

The Emerging Role of IL-9 in the Anticancer Effects of Anti-PD-1 Therapy

PD-1 blockade rescues failing anticancer immune responses, resulting in durable remissions in some cancer patients. Cytokines such as IFNγ and IL-2 contribute to the anti-tumor effect of PD-1 blockade. IL-9 was identified over the last decade as a cytokine demonstrating a potent ability to harness the anticancer functions of innate and adaptive immune cells in mice. Recent translational investigations suggest that the anticancer activity of IL-9 also extends to some human cancers. Increased T cell-derived IL-9 was proposed to predict the response to anti-PD-1 therapy. Preclinical investigations accordingly revealed that IL-9 could synergize with anti-PD-1 therapy in eliciting anticancer responses. Here, we review the findings suggesting an important contribution of IL-9 in the efficacy of anti-PD-1 therapy and discuss their clinical relevance. We will also discuss the role of host factors like the microbiota and TGFβ in the tumor microenvironment (TME) in the regulation of IL-9 secretion and anti-PD-1 treatment efficacy.

Pathogenesis of allergic diseases and implications for therapeutic interventions

Allergic diseases such as allergic rhinitis (AR), allergic asthma (AAS), atopic dermatitis (AD), food allergy (FA), and eczema are systemic diseases caused by an impaired immune system. Accompanied by high recurrence rates, the steadily rising incidence rates of these diseases are attracting increasing attention. The pathogenesis of allergic diseases is complex and involves many factors, including maternal-fetal environment, living environment, genetics, epigenetics, and the body's immune status. The pathogenesis of allergic diseases exhibits a marked heterogeneity, with phenotype and endotype defining visible features and associated molecular mechanisms, respectively. With the rapid development of immunology, molecular biology, and biotechnology, many new biological drugs have been designed for the treatment of allergic diseases, including anti-immunoglobulin E (IgE), anti-interleukin (IL)-5, and anti-thymic stromal lymphopoietin (TSLP)/IL-4, to control symptoms. For doctors and scientists, it is becoming more and more important to understand the influencing factors, pathogenesis, and treatment progress of allergic diseases. This review aimed to assess the epidemiology, pathogenesis, and therapeutic interventions of allergic diseases, including AR, AAS, AD, and FA. We hope to help doctors and scientists understand allergic diseases systematically.

Mass cytometry analysis identifies T cell immune signature of aplastic anemia and predicts the response to cyclosporine

Aplastic anemia (AA) is an auto-activated T cell-mediated bone marrow failure. Cyclosporine is often used to treat non-severe AA, which demonstrates a more heterogeneous condition than severe AA. The response rate to cyclosporine is only around 50% in non-severe AA. To better predict response to cyclosporine and pinpoint who is the appropriate candidate for cyclosporine, we performed phenotypic and functional T cell immune signature at single cell level by mass cytometry from 30 patients with non-severe AA. Unexpectedly, non-significant differences of T cell subsets were observed between AA and healthy control or cyclosporine-responder and non-responders. Interestingly, when screening the expression of co-inhibitory molecules, T cell trafficking mediators, and cytokines, we found an increase of cytotoxic T lymphocyte antigen 4 (CTLA-4) on T cells in response to cyclosporine and a lower level of CTLA-4 on CD8⁺ T cells was correlated to hematologic response. Moreover, a decreased expression of sphingosine-1-phosphate receptor 1 (S1P₁) on naive T cells and a lower level of interleukin-9 (IL-9) on T helpers also predicted a better response to cyclosporine, respectively. Therefore, the T cell immune signature, especially in CTAL-4, S1P₁, and IL-9, has a predictive value for response to cyclosporine. Collectively, our study implies that immune signature analysis of T cell by mass cytometry is a useful tool to make a strategic decision on cyclosporine treatment of AA.

Effect of T cells on bone

Bone and immune systems mutually influence each other by sharing a variety of regulatory molecules and the tissue microenvironment. The interdisciplinary research field "osteoimmunology" has illuminated the complex and dynamic interactions between the two systems in the maintenance of tissue homeostasis as well as in the development of immune and skeletal disorders. T cells play a central role in the immune response by secreting various immune factors and stimulating other immune cells and structural cells such as fibroblasts and epithelial cells, thereby contributing to pathogen elimination and pathogenesis of immune diseases. The finding on regulation of osteoclastic bone resorption by activated CD4⁺ T cells in rheumatoid arthritis was one of the driving forces for the development of osteoimmunology. With advances in research on helper T cell subsets and rare lymphoid cells such as γδ T cells in the immunology field, it is becoming clear that various types of T cells exert multiple effects on bone metabolism depending on immune context. Understanding the diverse effects of T cells on bone is essential for deciphering the osteoimmune regulatory network in various biological settings.

ERG Functionally Overlaps with Other Ets Proteins in Promoting TH9 Cell Expression of Il9 during Allergic Lung Inflammation

CD4+ TH cells develop into subsets that are specialized in the secretion of particular cytokines to mediate restricted types of inflammation and immune responses. Among the subsets that promote development of allergic inflammatory responses, IL-9-producing TH9 cells are regulated by a number of transcription factors. We have previously shown that the E26 transformation-specific (Ets) family members PU.1 and Ets translocation variant 5 (ETV5) function in parallel to regulate IL-9. In this study we identified a third member of the Ets family of transcription factors, Ets-related gene (ERG), that mediates IL-9 production in TH9 cells in the absence of PU.1 and ETV5. Chromatin immunoprecipitation assays revealed that ERG interaction at the Il9 promoter region is restricted to the TH9 lineage and is sustained during murine TH9 polarization. Knockdown or knockout of ERG during murine or human TH9 polarization in vitro led to a decrease in IL-9 production in TH9 cells. Deletion of ERG in vivo had modest effects on IL-9 production in vitro or in vivo. However, in the absence of PU.1 and ETV5, ERG was required for residual IL-9 production in vitro and for IL-9 production by lung-derived CD4 T cells in a mouse model of chronic allergic airway disease. Thus, ERG contributes to IL-9 regulation in TH9 cells.

Immunology of Giant Cell Arteritis

Giant cell arteritis is an autoimmune disease of medium and large arteries, characterized by granulomatous inflammation of the three-layered vessel wall that results in vaso-occlusion, wall dissection, and aneurysm formation. The immunopathogenesis of giant cell arteritis is an accumulative process in which a prolonged asymptomatic period is followed by uncontrolled innate immunity, a breakdown in self-tolerance, the transition of autoimmunity from the periphery into the vessel wall and, eventually, the progressive evolution of vessel wall inflammation. Each of the steps in pathogenesis corresponds to specific immuno-phenotypes that provide mechanistic insights into how the immune system attacks and damages blood vessels. Clinically evident disease begins with inappropriate activation of myeloid cells triggering the release of hepatic acute phase proteins and inducing extravascular manifestations, such as muscle pains and stiffness diagnosed as polymyalgia rheumatica. Loss of self-tolerance in the adaptive immune system is linked to aberrant signaling in the NOTCH pathway, leading to expansion of NOTCH1+CD4+ T cells and the functional decline of NOTCH4+ T regulatory cells (Checkpoint 1). A defect in the endothelial cell barrier of adventitial vasa vasorum networks marks Checkpoint 2; the invasion of monocytes, macrophages and T cells into the arterial wall. Due to the failure of the immuno-inhibitory PD-1 (programmed cell death protein 1)/PD-L1 (programmed cell death ligand 1) pathway, wall-infiltrating immune cells arrive in a permissive tissues microenvironment, where multiple T cell effector lineages thrive, shift toward high glycolytic activity, and support the development of tissue-damaging macrophages, including multinucleated giant cells (Checkpoint 3). Eventually, the vascular lesions are occupied by self-renewing T cells that provide autonomy to the disease process and limit the therapeutic effectiveness of currently used immunosuppressants. The multi-step process deviating protective to pathogenic immunity offers an array of interception points that provide opportunities for the prevention and therapeutic management of this devastating autoimmune disease.

Enhancement of T cell infiltration via tumor-targeted Th9 cell delivery improves the efficacy of antitumor immunotherapy of solid tumors

Insufficient infiltration of T cells severely compromises the antitumor efficacy of adoptive cell therapy (ACT) against solid tumors. Here, we present a facile immune cell surface engineering strategy aiming to substantially enhance the anti-tumor efficacy of Th9-mediated ACT by rapidly identifying tumor-specific binding ligands and improving the infiltration of infused cells into solid tumors. Non-genetic decoration of Th9 cells with tumor-targeting peptide screened from phage display not only allowed precise targeted ACT against highly heterogeneous solid tumors but also substantially enhanced infiltration of CD8⁺ T cells, which led to improved antitumor outcomes. Mechanistically, infusion of Th9 cells modified with tumor-specific binding ligands facilitated the enhanced distribution of tumor-killing cells and remodeled the immunosuppressive microenvironment of solid tumors via IL-9 mediated immunomodulation. Overall, we presented a simple, cost-effective, and cell-friendly strategy to enhance the efficacy of ACT against solid tumors with the potential to complement the current ACT.

IL-9 stimulates an anti-tumor immune response and facilitates immune checkpoint blockade in the CMT167 mouse model

OBJECTIVES

There is mounting evidence that interleukin-9 (IL-9) is associated with various cancers although its function in lung cancer remains elusive. This study aimed to elucidate the role(s) of IL-9 in lung cancer and the mechanisms involved.

MATERIALS AND METHODS

Expression of IL-9 receptor (IL-9R) in two murine lung cancer cell lines: CMT167 and Lewis lung carcinoma (LLC) were assessed and syngeneic murine lung cancer models were established. Tumor growth, intratumoral immune responses and downstream signaling pathways in tumor-bearing mice were analyzed upon IL-9 treatment. Human lung cancer cell lines A549 and H1975 were included for in vitro validation. Synergistic effects and immune responses of IL-9 in combination with anti-PD-1 were studied.

RESULTS

IL-9R expression was only detected in CMT167 but not LLC cells. IL-9 suppressed CMT167 tumor growth and enhanced anti-tumor T cell responses, both of which were absent in IL-9R-deficient LLC model and lost upon IL-9R knockdown in CMT167 model. In CMT167 tumors, while IL-9 increased CD4⁺ and CD8⁺ T cells and dendritic cells, the cytotoxic T subset was the key driver of IL-9-induced tumor suppression. Consistently, in CMT167 and A549 cells, IL-9/IL-9R signaling promoted MHC class I upregulation. Inhibition of ERK signaling abolished IL-9-mediated MHC class I upregulation in CMT167 cells. IL-9 induced expression of PD-1 and PD-L1 on CD8⁺ T lymphocytes and CMT167 cells respectively. Combined IL-9 treatment with PD-1 blockade further upregulated tumor-infiltrating CD8⁺ T cell frequencies and synergistically suppressed tumor growth in CMT167 model.

CONCLUSION

IL-9 suppresses tumor growth by promoting tumor-derived MHC class I presentation and enhancing cytotoxic T cell immunity. Expression of IL-9R might be used as a biomarker for identification of potential target population susceptible to IL-9 treatment. Our study proposes IL-9 as a promising therapeutic immunomodulatory agent that can be used in combination with PD-1 blockade in lung cancer.

Allergen immunotherapy, cancer, and immune disorders

PURPOSE OF REVIEW

The purpose of this review is to provide an update on the intriguing relationships between allergies, allergen immunotherapy, cancer, and immune disorders. Allergic diseases and cancer are increasing in incidence and prevalence and a potential relationship, or not, between these diseases have been suggested for many years.

RECENT FINDINGS

Recent findings suggest that there may be some causative effects between certain types of cancer and allergic diseases, as described in the text. Some types of cancer may be more linked to the presence of an allergic disease, than others. However, epigenetic factors, such as tobacco smoke alcohol and toxic substances should also be taken into consideration.

SUMMARY

The association between allergy and cancer is complex and depends on the specific allergy and the specific organ under consideration. Regarding pancreatic cancer, colorectal cancer (CRC), and glioma, all types of allergies were shown to be a protective factor. Conversely, asthma is a risk factor for lung cancer as is atopic dermatitis for skin cancer. Despite extensive research, no definite relationship has been determined, and no clear relationship, either positive or negative, to allergies can be observed. These results should be corroborated with large epidemiological well designed prospective studies due to some weaknesses in the previous investigations.

The impact of type 2 immunity and allergic diseases in atherosclerosis

Allergic diseases are allergen-induced immunological disorders characterized by the development of type 2 immunity and IgE responses. The prevalence of allergic diseases has been on the rise alike cardiovascular disease (CVD), which affects arteries of different organs such as the heart, the kidney and the brain. The underlying cause of CVD is often atherosclerosis, a disease distinguished by endothelial dysfunction, fibrofatty material accumulation in the intima of the artery wall, smooth muscle cell proliferation, and Th1 inflammation. The opposed T-cell identity of allergy and atherosclerosis implies an atheroprotective role for Th2 cells by counteracting Th1 responses. Yet, the clinical association between allergic disease and CVD argues against it. Within, we review different phases of allergic pathology, basic immunological mechanisms of atherosclerosis and the clinical association between allergic diseases (particularly asthma, atopic dermatitis, allergic rhinitis and food allergy) and CVD. Then, we discuss putative atherogenic mechanisms of type 2 immunity and allergic inflammation including acute allergic reactions (IgE, IgG1, mast cells, macrophages and allergic mediators such as vasoactive components, growth factors and those derived from the complement, contact and coagulation systems) and late phase inflammation (Th2 cells, eosinophils, type 2 innate-like lymphoid cells, alarmins, IL-4, IL-5, IL-9, IL-13 and IL-17).

Prognosis and immune response of a cuproptosis-related lncRNA signature in low grade glioma

Cuproptosis is a newly discovered new mechanism of programmed cell death, and its unique pathway to regulate cell death is thought to have a unique role in understanding cancer progression and guiding cancer therapy. However, this regulation has not been studied in low grade glioma (LGG) at present. In this study, data on low grade glioma patients were downloaded from the TCGA database. We screened the genes related to cuproptosis from the published papers and confirmed the lncRNAs related to them. We applied univariate/multivariate, and LASSO regression algorithms, finally identified 11 lncRNAs for constructing prognosis prediction models, and constructed a risk scoring model. The reliability and validity test of the model indicated that the model could well distinguish the prognosis and survival of LGG patients. Furthermore, the analyses of immunotherapy, immune microenvironment, as well as functional enrichment were also performed. Finally, we verified the expression of these six prognostic key lncRNAs using real-time polymerase chain reaction (RT-PCR). In conclusion, this study is the first analysis based on cuproptosis-related lncRNAs in LGG and aims to open up new directions for LGG therapy.

Opposing functions of circadian protein DBP and atypical E2F family E2F8 in anti-tumor Th9 cell differentiation

Interleukin-9 (IL-9)-producing CD4⁺ T helper cells (Th9) have been implicated in allergy/asthma and anti-tumor immunity, yet molecular insights on their differentiation from activated T cells, driven by IL-4 and transforming growth factor-beta (TGF-β), is still lacking. Here we show opposing functions of two transcription factors, D-binding protein (DBP) and E2F8, in controlling Th9 differentiation. Specifically, TGF-β and IL-4 signaling induces phosphorylation of the serine 213 site in the linker region of the Smad3 (pSmad3L-Ser²¹³) via phosphorylated p38, which is necessary and sufficient for Il9 gene transcription. We identify DBP and E2F8 as an activator and repressor, respectively, for Il9 transcription by pSmad3L-Ser²¹³. Notably, Th9 cells with siRNA-mediated knockdown for Dbp or E2f8 promote and suppress tumor growth, respectively, in mouse tumor models. Importantly, DBP and E2F8 also exhibit opposing functions in regulating human TH9 differentiation in vitro. Thus, our data uncover a molecular mechanism of Smad3 linker region-mediated, opposing functions of DBP and E2F8 in Th9 differentiation.

Two novel predictive biomarkers for osteosarcoma and glycolysis pathways: A profiling study on HS2ST1 and SDC3

INTRODUCTION

Prognostic biomarkers for osteosarcoma (OS) are still very few, and this study aims to examine 2 novel prognostic biomarkers for OS through combined bioinformatics and experimental approach.

MATERIALS AND METHODS

Expression profile data of OS and paraneoplastic tissues were downloaded from several online databases, and prognostic genes were screened by differential expression analysis, Univariate Cox analysis, least absolute shrinkage and selection operator regression analysis, and multivariate Cox regression analysis to construct prognostic models. The accuracy of the model was validated using principal component analysis, constructing calibration plots, and column line plots. We also analyzed the relationship between genes and drug sensitivity. Gene expression profiles were analyzed by immunocytotyping. Also, protein expressions of the constructed biomarkers in OS and paraneoplastic tissues were verified by immunohistochemistry.

RESULTS

Heparan sulfate 2-O-sulfotransferase 1 (HS2ST1) and Syndecan 3 (SDC3, met all our requirements after screening. The constructed prognostic model indicated that patients in the high-risk group had a much lower patient survival rate than in the low-risk group. Moreover, these genes were closely related to immune cells (P < .05). Drug sensitivity analysis showed that the 2 genes modeled were strongly correlated with multiple drugs. Immunohistochemical analysis showed significantly higher protein expression of both genes in OS than in paraneoplastic tissues.

CONCLUSIONS

HS2ST1 and SDC3 are significantly dysregulated in OS, and the prognostic models constructed based on these 2 genes have much lower survival rates in the high-risk group than in the low-risk group. HS2ST1 and SDC3 can be used as glycolytic and immune-related prognostic biomarkers in OS.

Distinct spatial and temporal roles for Th1, Th2, and Th17 cells in asthma

Immune response in the asthmatic respiratory tract is mainly driven by CD4⁺ T helper (Th) cells, represented by Th1, Th2, and Th17 cells, especially Th2 cells. Asthma is a heterogeneous and progressive disease, reflected by distinct phenotypes orchestrated by τh2 or non-Th2 (Th1 and Th17) immune responses at different stages of the disease course. Heterogeneous cytokine expression within the same Th effector state in response to changing conditions in vivo and interlineage relationship among CD4⁺ T cells shape the complex immune networks of the inflammatory airway, making it difficult to find one panacea for all asthmatics. Here, we review the role of three T helper subsets in the pathogenesis of asthma from different stages, highlighting timing is everything in the immune system. We also discuss the dynamic topography of Th subsets and pathogenetic memory Th cells in asthma.

Foxp2 inhibits Th9 cell differentiation and attenuates allergic airway inflammation in a mouse model of ovalbumin-induced asthma

This study aimed to explore the effects of forkhead box P2 gene (Foxp2) on T-helper 9 (Th9) differentiation in asthmatic mice. An in vivo asthmatic mouse model was induced with ovalbumin (OVA). An in vitro model was established by culturing CD4⁺ T cells with TGF-β, IL-4, and anti-IFN-γ. ELISA, flow cytometry, qRT-PCR and Western blot were performed to examine IL-9 secretion, Th9 cell number, and Th9 cell transcription factor expression, respectively. Pathological changes in lung tissues and airway mucus secretion were assessed with HE and PAS glycogen staining. Anti-IL-9 mAb reversed the elevation in Th9 cells and IL-9 expression in lung tissues and bronchoalveolar lavage fluid (BALF) of asthmatic mice. Foxp2 was downregulated in BALF and lung tissue of asthmatic mice and Th9 cells. Overexpression of Foxp2 inhibited Th9 cell differentiation in vitro and improved airway inflammation in vivo. Our study suggests that overexpression of Foxp2 attenuates allergic asthma by inhibiting Th9 cell differentiation.

The Mechanisms of Effector Th Cell Responses Contribute to Treg Cell Function: New Insights into Pathogenesis and Therapy of Asthma

CD4 ⁺ helper T (Th) cell subsets are critically involved in the pathogenesis of asthma. Naive Th cells differentiate into different subsets under the stimulation of different sets of cytokines, and the differentiation process is dominantly driven by lineage specific transcription factors, such as T-bet (Th1), GATA3 (Th2), RORγt (Th17) and Foxp3 (Treg). The differentiation mechanisms driven by these transcription factors are mutually exclusive, resulting in functional inhibition of these Th subsets to each other, particularly prominent between effector Th cells and Treg cells, such as Th2 versus Treg cells and Th17 versus Treg cells. Being of significance in maintaining immune homeostasis, the balance between effector Th cell response and Treg cell immunosuppression provides an immunological theoretical basis for us to understand the immunopathological mechanism and develop the therapy strategies of asthma. However, recent studies have found that certain factors involved in effector Th cells response, such as cytokines and master transcription factors (IL-12 and T-bet of Th1, IL-4 and GATA3 of Th2, IL-6 and RORγt of Th17), not only contribute to immune response of effector Th cells, but also promote the development and function of Treg cells, therefore bridging the interplay between effector Th cell immune responses and Treg cell immunosuppression. Although we have an abundant knowledge concerning the role of these cytokines and transcription factors in effector Th cell responses, our understanding on their role in Treg cell development and function is scattered thus need to be summarized. This review summarized the role of these cytokines and transcription factors involved in effector Th cell responses in the development and function of Treg cells, in the hope of providing new insights of understanding the immunopathological mechanism and seeking potential therapy strategies of asthma.

Mouse pulmonary interstitial macrophages mediate the pro-tumorigenic effects of IL-9

Although IL-9 has potent anti-tumor activity in adoptive cell transfer therapy, some models suggest that it can promote tumor growth. Here, we show that IL-9 signaling is associated with poor outcomes in patients with various forms of lung cancer, and is required for lung tumor growth in multiple mouse models. CD4+ T cell-derived IL-9 promotes the expansion of both CD11c+ and CD11c- interstitial macrophage populations in lung tumor models. Mechanistically, the IL-9/macrophage axis requires arginase 1 (Arg1) to mediate tumor growth. Indeed, adoptive transfer of Arg1+ but not Arg1- lung macrophages to Il9r-/- mice promotes tumor growth. Moreover, targeting IL-9 signaling using macrophage-specific nanoparticles restricts lung tumor growth in mice. Lastly, elevated expression of IL-9R and Arg1 in tumor lesions is associated with poor prognosis in lung cancer patients. Thus, our study suggests the IL-9/macrophage/Arg1 axis is a potential therapeutic target for lung cancer therapy.

Immune System Modulation by the Adjuvants Poly (I:C) and Montanide ISA 720

Adjuvants are essential for vaccine development, especially subunit-based vaccines such as those containing recombinant proteins. Increasing the knowledge of the immune response mechanisms generated by adjuvants should facilitate the formulation of vaccines in the future. The present work describes the immune phenotypes induced by Poly (I:C) and Montanide ISA 720 in the context of mice immunization with a recombinant protein based on the Plasmodium vivax circumsporozoite protein (PvCSP) sequence. Mice immunized with the recombinant protein plus Montanide ISA 720 showed an overall more robust humoral response, inducing antibodies with greater avidity to the antigen. A general trend for mixed Th1/Th2 inflammatory cytokine profile was increased in Montanide-adjuvanted mice, while a balanced profile was observed in Poly (I:C)-adjuvanted mice. Montanide ISA 720 induced a gene signature in B lymphocytes characteristic of heme biosynthesis, suggesting increased differentiation to Plasma Cells. On the other hand, Poly (I:C) provoked more perturbations in T cell transcriptome. These results extend the understanding of the modulation of specific immune responses induced by different classes of adjuvants, and could support the optimization of subunit-based vaccines.

GATA2-Mediated Transcriptional Activation of Notch3 Promotes Pancreatic Cancer Liver Metastasis

The liver is the predominant metastatic site for pancreatic cancer. However, the factors that determine the liver metastasis and the specific molecular mechanisms are still unclear. In this study, we used human pancreatic cancer cell line Hs766T to establish Hs766T-L3, a subline of Hs766T with stable liver metastatic ability. We performed RNA sequencing of Hs766T-L3 and its parental cell line Hs766T, and revealed huge differences in gene expression patterns and pathway activation between these two cell lines. We correlated the difference in pathway activation with the expression of the four core transcriptional factors including STAT1, NR2F2, GATA2, and SMAD4. Using the TCGA database, we examined the relative expression of these transcription factors (TFs) in pan-cancer and their relationship with the prognosis of the pancreatic cancer. Among these TFs, we considered GATA2 is closely involved in tumor metastasis and may serve as a potential metastatic driver. Further in vitro and in vivo experiments confirmed that GATA2-mediated transcriptional activation of Notch3 promotes the liver metastasis of Hs766T-L3, and knockdown of either GATA2 or Notch3 reduces the metastatic ability of Hs766T-L3. Therefore, we claim that GATA2 may serve as a metastatic driver of pancreatic cancer and a potential therapeutic target to treat liver metastasis of pancreatic cancer.

Immunologie Update für Dermatologen – woran wird geforscht?

Immuntherapien haben die Behandlung der chronischen Dermatosen enorm vorangebracht. Immunologische Diagnostik bestimmt den Alltag in der Praxis. Viele Dermatologen impfen. Nicht zuletzt die allgegenwärtige Corona-Pandemie und die Entwicklung entsprechender Impfstoffe verdeutlichen das große Forschungspotenzial in der Immunologie. Wir versuchen, einen Überblick zu geben, woran aktuell immunologisch geforscht wird und was wir in naher Zukunft zu erwarten haben.

Emerging Paradigms in Type 2 Immunity

A principal purpose of type 2 immunity was thought to be defense against large parasites, but it also functions in the restoration of homeostasis, such as toxin clearance following snake bites. In other cases, like allergy, the type 2 T helper (Th2) cytokines and cells present in the environment are detrimental and cause diseases. In recent years, the recognition of cell heterogeneity within Th2-associated cell populations has revealed specific functions of cells with a particular phenotype or gene signature. In addition, here we discuss the recent data regarding heterogeneity of type 2 immunity-related cells, as well as their newly identified role in a variety of processes ranging from involvement in respiratory viral infections [especially in the context of the recent COVID-19 (coronavirus disease 2019) pandemic] to control of cancer development or of metabolic homeostasis.

Alarmin Cytokines as Central Regulators of Cutaneous Immunity

Skin acts as the primary interface between the body and the environment. The skin immune system is composed of a complex network of immune cells and factors that provide the first line of defense against microbial pathogens and environmental insults. Alarmin cytokines mediate an intricate intercellular communication between keratinocytes and immune cells to regulate cutaneous immune responses. Proper functions of the type 2 alarmin cytokines, thymic stromal lymphopoietin (TSLP), interleukin (IL)-25, and IL-33, are paramount to the maintenance of skin homeostasis, and their dysregulation is commonly associated with allergic inflammation. In this review, we discuss recent findings on the complex regulatory network of type 2 alarmin cytokines that control skin immunity and highlight the mechanisms by which these cytokines regulate skin immune responses in host defense, chronic inflammation, and cancer.

The Role of Autophagy in the Function of CD4+ T Cells and the Development of Chronic Inflammatory Diseases

Uncontrolled acute inflammation progresses to persistent inflammation that leads to various chronic inflammatory diseases, including asthma, Crohn’s disease, rheumatoid arthritis, multiple sclerosis, and systemic lupus erythematosus. CD4⁺ T cells are key immune cells that determine the development of these chronic inflammatory diseases. CD4⁺ T cells orchestrate adaptive immune responses by producing cytokines and effector molecules. These functional roles of T cells vary depending on the surrounding inflammatory or anatomical environment. Autophagy is an important process that can regulate the function of CD4⁺ T cells. By lysosomal degradation of cytoplasmic materials, autophagy mediates CD4⁺ T cell-mediated immune responses, including cytokine production, proliferation, and differentiation. Furthermore, through canonical processes involving autophagy machinery, autophagy also contributes to the development of chronic inflammatory diseases. Therefore, a targeted intervention of autophagy processes could be used to treat chronic inflammatory diseases. This review focuses on the role of autophagy via CD4⁺ T cells in the pathogenesis and treatment of such diseases. In particular, we explore the underlying mechanisms of autophagy in the regulation of CD4⁺ T cell metabolism, survival, development, proliferation, differentiation, and aging. Furthermore, we suggest that autophagy-mediated modulation of CD4⁺ T cells is a promising therapeutic target for treating chronic inflammatory diseases.