Th22 response induced by Mycobacterium tuberculosis strains is closely related to severity of pulmonary lesions and bacillary load in patients with multi-drug-resistant tuberculosis

Transforming growth factor-β, Interleukin-23 and interleukin-1β modulate TH22 response during active multidrug-resistant tuberculosis

We previously reported that patients with multidrug-resistant tuberculosis (MDR-TB) showed low systemic and Mtb-induced Th22 responses associated to high sputum bacillary load and severe lung lesions suggesting that Th22 response could influence the ability of these patients to control bacillary growth and tissue damage. In MDR-TB patients, the percentage of IL-22+ cells inversely correlates with the proportion of senescent PD-1+ T cells. Herein, we aimed to evaluate the pathways involved on the regulation of systemic and Mtb-induced Th22 response in MDR-TB and fully drug-susceptible TB patients (S-TB) and healthy donors. Our results show that while IL-1β and IL-23 promote Mtb-induced IL-22 secretion and expansion of IL-22+ cells, TGF-β inhibits this response. Systemic and in vitro Mtb-induced Th22 response inversely correlates with TGF-β amounts in plasma and in PBMC cultures respectively. The number of circulating PD-1+ T cells directly correlates with plasmatic TGF-β levels and blockade of PD-1/PD-L1 signalling enhances in vitro Mtb-induced expansion of IL-22+ cells. Thus, TGF-β could also inhibit Th22 response through upregulation of PD-1 expression in T cells. Higher percentage of IL-23+ monocytes was observed in TB patients. In contrast, the proportion of IL-1β+ monocytes was lower in TB patients with bilateral lung cavities (BCC) compared to those patients with unilateral cavities (UCC). Interestingly, TB patients with BCC showed higher plasmatic and Mtb-induced TGF-β secretion than patients with UCC. Thus, high TGF-β secretion and subtle differences in IL-23 and IL-1β expression could diminish systemic and in vitro Mtb-induced Th22 response along disease progression in TB patients.

Characteristics of Serum Autoantibody Repertoire and Immune Subgroup Variation of Tuberculosis-Associated Obstructive Pulmonary Disease

Background

Studying the potential etiology and pathogenesis of tuberculosis-associated chronic obstructive pulmonary disease (TOPD) from an autoimmunity perspective may provide insights into peripheral blood autoantibodies and immune cells, as well as their interactions.

Methods

This study examined the serum autoantibody repertoire in healthy individuals, patients with chronic obstructive pulmonary disease (COPD), patients with pulmonary tuberculosis (TB), and TOPD patients using the HuProtTM protein chip. Autoantigens in the peripheral blood of TOPD patients were verified using ELISA assay. Various epitopes and immune simulation were predicted using bioinformatic methods. Flow cytometry was employed to detect macrophages(Mφ), T cells, and innate lymphoid cells (ILCs) in the peripheral blood.

Results

COPD patients displayed distinct alterations in their IgG and IgM autoantibodies compared to the other groups. GeneOntology (GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG)analyses revealed that these autoantibodies were associated with regulating macrophages, T cells, and B cells. ELISA results confirmed the upregulation of expression of proliferating cell nuclear antigen (PCNA), Mitogen-Activated Protein Kinase 3 antigen (MAPK3), and threonine protein kinase 1 antigen (AKT1) proteins in the peripheral blood of TOPD patients. Bioinformatic analysis predicted multiple potential epitopes in Th, CTL, and B cells. Immune simulation results demonstrated that PCNA, MAPK3, and AKT1 can activate innate and adaptive immune responses and induce the expression of different cytokines, such as IFN-g and IL-2. Furthermore, data obtained from flow cytometry assay revealed an upregulation in the face of Th1 cells in the peripheral blood of TOPD patients.

Conclusion

Tuberculosis infection can effectively induce autoimmune responses, contributing to increased expression of Th1 cells and associated cytokines, ultimately leading to immune dysregulation. Furthermore, the accumulation of pulmonary inflammatory response facilitates the progression of TOPD and is helpful for the clinical diagnosis and the development of targeted therapeutic drugs for this disease.

Helper T cell bias following tuberculosis chemotherapy identifies opportunities for therapeutic vaccination to prevent relapse

Therapeutic vaccines have promise as adjunctive treatment for tuberculosis (TB) or as preventives against TB relapse. An important development challenge is the limited understanding of T helper (Th) cell roles during these stages of disease. A murine model of TB relapse was used to identify changes in Th populations and cytokine microenvironment. Active TB promoted expansion of Th1, Th2, Th17, and Th22 cells and cytokines in the lung. Following drug therapy, pulmonary Th17 and Th22 cells contracted, Th1 cells remained elevated, while Th cells producing IL-4 or IL-10 expanded. At relapse, Th22 cells failed to re-expand in the lung despite a moderate re-expansion of Th1 and Th17 cells and an increase in Th cytokine polyfunctionality. The dynamics of Th populations further differed by tissue compartment and disease presentation. These outcomes identify immune bias by Th subpopulations during TB relapse as candidate mechanisms for pathogenesis and targets for therapeutic vaccination.

Possible Mechanisms of Lymphopenia in Severe Tuberculosis

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis). In lymphopenia, T cells are typically characterized by progressive loss and a decrease in their count results. Lymphopenia can hinder immune responses and lead to systemic immunosuppression, which is strongly associated with mortality. Lymphopenia is a significant immunological abnormality in the majority of patients with severe and advanced TB, and its severity is linked to disease outcomes. However, the underlying mechanism remains unclear. Currently, the research on the pathogenesis of lymphopenia during M. tuberculosis infection mainly focuses on how it affects lymphocyte production, survival, or tissue redistribution. This includes impairing hematopoiesis, inhibiting T-cell proliferation, and inducing lymphocyte apoptosis. In this study, we have compiled the latest research on the possible mechanisms that may cause lymphopenia during M. tuberculosis infection. Lymphopenia may have serious consequences in severe TB patients. Additionally, we discuss in detail potential intervention strategies to prevent lymphopenia, which could help understand TB immunopathogenesis and achieve the goal of preventing and treating severe TB.

Rifampicin drug resistance and host immunity in tuberculosis: more than meets the eye

Tuberculosis (TB) is the leading cause of death due to an infectious agent, with more than 1.5 million deaths attributed to TB annually worldwide. The global dissemination of drug resistance across Mycobacterium tuberculosis (Mtb) strains, causative of TB, resulted in an estimated 450 000 cases of drug-resistant (DR) TB in 2021. Dysregulated immune responses have been observed in patients with multidrug resistant (MDR) TB, but the effects of drug resistance acquisition and impact on host immunity remain obscure. In this review, we compile studies that span aspects of altered host-pathogen interactions and highlight research that explores how drug resistance and immunity might intersect. Understanding the immune processes differentially induced during DR TB would aid the development of rational therapeutics and vaccines for patients with MDR TB.

Current Knowledge of Th22 Cell and IL-22 Functions in Infectious Diseases

T helper 22 (Th22) cells, a newly defined CD4+ T-cell lineage, are characterized by their distinct cytokine profile, which primarily consists of IL-13, IL-22 and TNF-α. Th22 cells express a wide spectrum of chemokine receptors, such as CCR4, CCR6 and CCR10. The main effector molecule secreted by Th22 cells is IL-22, a member of the IL-10 family, which acts by binding to IL-22R and triggering a complex downstream signaling system. Th22 cells and IL-22 have been found to play variable roles in human immunity. In preventing the progression of infections such as HIV and influenza, Th22/IL-22 exhibited protective anti-inflammatory characteristics, and their deleterious proinflammatory activities have been demonstrated to exacerbate other illnesses, including hepatitis B and Helicobacter pylori infection. Herein, we review the current understanding of Th22 cells, including their definition, differentiation and mechanisms, and the effect of Th22/IL-22 on human infectious diseases. According to studies on Th22 cells, Th22/IL-22 may be a promising therapeutic target and an effective treatment strategy for various infections.

Role of interleukin-22 in tuberculosis patients

OBJECTIVES

Disease progression of tuberculosis (TB) depends on the balance between the microorganism's virulence and the host defense systems (mainly T cell-mediated immune response). Interleukin-22 (IL-22) helps in cell proliferation and regeneration and provides protection against microbial diseases. The IL-22-producing T cells can migrate into the granulomas during TB infection. However, disparity exists in literature regarding its role. The present study aims to compare serum IL-22 levels and its' expression in TB patients and healthy controls.

METHODS

87 TB patients and 85 healthy subjects were enrolled in the study. Under aseptic conditions, venous blood was withdrawn. Serum IL-22 levels were estimated using enzyme-linked immunosorbent assay, and its gene expression was assessed using SYBR green-based quantitative PCR technology. A statistical analysis was performed using SPSS.

RESULTS

The median (interquartile range) of serum IL-22 levels was significantly lower in TB patients (18.55 (5.08) pg/mL) when compared to controls (49.38 (162.88) pg/mL) (p<0.0001). The IL-22 expression was significantly upregulated with a fold change value of 29.44 in TB patients.

CONCLUSIONS

The IL-22 levels were found to be significantly decreased in patients, contradictory to its expression, which is upregulated. It plays a crucial role for the modulation of tissues in response to TB infection.

Microsporum gypseum Isolated from Ailuropoda melanoleuca Provokes Inflammation and Triggers Th17 Adaptive Immunity Response

Microsporum gypseum causes dermatomycoses in giant pandas (Ailuropoda melanoleuca). This study aimed to investigate the immune response of M. gypseum following deep infection. The degree of damage to the heart, liver, spleen, lungs, and kidneys was evaluated using tissue fungal load, organ index, and histopathological methods. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) detected the mRNA expression of receptors and cytokines in the lung, and immunofluorescence staining and flow cytometry, were used to assess immune cells in the lung. The results indicated that conidia mainly colonized the lungs and caused serious injury with M. gypseum infection. Furthermore, dectin-1, TLR-2, and TLR-4 played a role in recognizing M. gypseum cells. Numerous inflammatory cells, mainly macrophages, dendritic cells, polymorphonuclear neutrophils, and inflammatory cytokines (TGF-β, TNF-α, IL-1β, IL-6, IL-10, IL-12, and IL-23), were activated in the early stages of infection. With the high expression of IL-22, IL-17A, and IL-17F, the Th17 pathway exerted an adaptive immune response to M. gypseum infection. These results can potentially aid in the diagnosis and treatment of diseases caused by M. gypseum in giant pandas.

Evaluation of tuberculosis diagnostic biomarkers in immunocompromised hosts based on cytokine levels in QuantiFERON-TB Gold Plus

Tuberculosis (TB) remains a serious health concern globally. QuantiFERON-TB (QFT) is a diagnostic tool for TB detection, and its sensitivity is reduced in immunocompromised hosts with low T lymphocyte counts or abnormal T cell function. This study aimed to evaluate the correlation between T cell and cytokine levels in patients with active TB using QFT-Plus. Forty-five patients with active TB were enrolled, and the cytokines in QFT-Plus tube supernatants were quantified using the MAGPIX System. CD4⁺ T cell count negatively correlated with patient age (p < 0.001, r = -0.51). The levels of TB1-responsive interleukin-1 receptor antagonist (IL-1Ra) and IL-2 correlated with CD4⁺ T cell count, whereas the levels of TB2-responsive IL-1Ra and IFN-γ-induced protein 10 correlated with both CD4⁺ and CD8⁺ T cell counts. Cytokines that correlated with CD4⁺ and CD8⁺ T cell counts might not be suitable TB diagnostic biomarkers in immunocompromised hosts. Notably, cytokines that did not correlate with the T cell counts, such as monocyte chemoattractant protein-1, might be candidate biomarkers for TB in immunocompromised hosts. Our findings might help improve TB diagnosis, which could enable prompt treatment and minimize poor disease outcomes.

Characterization of Mycobacterium tuberculosis-Specific Th22 Cells and the Effect of Tuberculosis Disease and HIV Coinfection

The development of a highly effective tuberculosis (TB) vaccine is likely dependent on our understanding of what constitutes a protective immune response to TB. Accumulating evidence suggests that CD4+ T cells producing IL-22, a distinct subset termed "Th22" cells, may contribute to protective immunity to TB. Thus, we characterized Mycobacterium tuberculosis-specific Th22 (and Th1 and Th17) cells in 72 people with latent TB infection or TB disease, with and without HIV-1 infection. We investigated the functional properties (IFN-γ, IL-22, and IL-17 production), memory differentiation (CD45RA, CD27, and CCR7), and activation profile (HLA-DR) of M. tuberculosis-specific CD4+ T cells. In HIV-uninfected individuals with latent TB infection, we detected abundant circulating IFN-γ-producing CD4+ T cells (median, 0.93%) and IL-22-producing CD4+ T cells (median, 0.46%) in response to M. tuberculosis The frequency of IL-17-producing CD4+ T cells was much lower, at a median of 0.06%. Consistent with previous studies, IL-22 was produced by a distinct subset of CD4+ T cells and not coexpressed with IL-17. M. tuberculosis-specific IL-22 responses were markedly reduced (median, 0.08%) in individuals with TB disease and HIV coinfection compared with IFN-γ responses. M. tuberculosis-specific Th22 cells exhibited a distinct memory and activation phenotype compared with Th1 and Th17 cells. Furthermore, M. tuberculosis-specific IL-22 was produced by conventional CD4+ T cells that required TCR engagement. In conclusion, we confirm that Th22 cells are a component of the human immune response to TB. Depletion of M. tuberculosis-specific Th22 cells during HIV coinfection may contribute to increased risk of TB disease.

The Role of T Helper 22 Cells in Dermatological Disorders

T helper 22 (Th22) cells are a newly identified subset of CD4+ T cells that secrete the effector cytokine interleukin 22 (IL-22) upon specific antigen stimulation, barely with IFN-γ or IL-17. Increasing studies have demonstrated that Th22 cells and IL-22 play essential roles in skin barrier defense and skin disease pathogenesis since the IL-22 receptor is widely expressed in the skin, especially in keratinocytes. Herein, we reviewed the characterization, differentiation, and biological activities of Th22 cells and elucidated their roles in skin health and disease. We mainly focused on the intricate crosstalk between Th22 cells and keratinocytes and provided potential therapeutic strategies targeting the Th22/IL-22 signaling pathway.

The Age-Dependent Role of Th22, Tc22, and Tc17 Cells in the Severity of Pneumonia in COVID-19 Immunopathogenesis

Coronavirus disease 2019 (COVID-19) has clinical manifestations ranging from mild symptoms to respiratory failure, septic shock, and multi-organ failure. Lymphocytes are divided into different subtypes based on their cytokine production pattern. In this study, we investigated the role of cytokine expressions of CD4⁺ T (T helper [Th]1, Th2, Th17, Th22) and CD8⁺ T cell subtypes (T cytotoxic [Tc]1, Tc2, Tc17, Tc22) in the pathogenesis of COVID-19. Peripheral blood mononuclear cells (PBMCs) were extracted with Ficoll by density gradient centrifugation from blood samples of 180 COVID-19 patients (children and adults) and 30 healthy controls. PBMCs were stimulated with PMA and Ionomycin and treated with Brefeldin A in the fourth hour, and a 10-colored monoclonal antibody panel was evaluated at the end of the sixth hour using flow cytometry. According to our findings, the numbers of Th22 (CD3⁺, CD4⁺, and interleukin [IL]-22⁺) and Tc22 (CD3⁺, CD8⁺, IL-22⁺) cells increased in adult patients regardless of the level of pneumonia (mild, severe, or symptom-free) as compared with healthy controls (p < 0.05). In addition, the number of Tc17 (CD3⁺, CD8⁺, and IL-17A⁺) cells increased in low pneumonia and severe pneumonia groups compared with the healthy controls (p < 0.05). Both IL-22 and IL-17A production decreased during a follow-up within 6 weeks of discharge. Our findings suggest that the increase in only IL-22 expressed Tc22 cells in the 0-12 age group with a general symptom-free course and higher levels of Th22 and Tc22 in uncomplicated adult cases may indicate the protective effect of IL-22. On the contrary, the association between the severity of pneumonia and the elevation of Tc17 cells in adults may reveal the damaging effect of IL-22 when it is co-expressed with IL-17.

The interplay between airway epithelium and the immune system - A primer for the respiratory clinician

The respiratory epithelium is one of the primary interfaces between the body's immune system and the external environment. This review discusses the innate and adaptive immunomodulatory effects of the respiratory epithelium, highlighting the physiologic immune responses associated with health and the disease-causing sequelae when these physiologic responses go awry. Airway macrophages, dendritic cells, and innate lymphoid cells are discussed as orchestrators of physiological and pathological innate immune responses and T cells, B cells, mast cells, and granulocytes (eosinophils and neutrophils) as orchestrators of physiologic and pathologic adaptive immune responses. The interplay between the airway epithelium and the varied immune cells as well as the interplay between these immune cells is discussed, highlighting the importance of the dose of noxious stimuli and pathogens in immune programming and the timing of their interaction with the immune cells that determine the pattern of immune responses. Although each cell type has been researched individually, this review highlights the need for simultaneous temporal investigation of immune responses from these varied cells to noxious stimuli and pathogens.