Comparison of interferon-γ-, interleukin (IL)-17- and IL-22-expressing CD4 T cells, IL-22-expressing granulocytes and proinflammatory cytokines during latent and active tuberculosis infection

Prognosis of patients diagnosed with latent tuberculosis infection at dialysis initiation

BACKGROUND

The prognosis of Japanese dialysis patients diagnosed with latent tuberculosis infection (LTBI) at the time of starting dialysis remains unclear. The purpose of this study was to examine whether there is a difference in prognosis between incident dialysis patients with and without LTBI.

METHODS

A retrospective study of incident dialysis patients who underwent an interferon-gamma release assay (T-SPOT test) within 1 year before or after dialysis initiation at our hospital between May 1, 2013, and December 31, 2021 was conducted. Using propensity score matching (PSM), survival of the non-LTBI and LTBI groups was compared after adjusting for patient background characteristics.

RESULTS

Of the 737 incident dialysis patients, 276 (37.4%) underwent the T-SPOT test, of whom 23 (8.3%) were diagnosed with LTBI. After matching for age, sex, activities of daily living (ADL), estimated glomerular filtration rate (eGFR), Charlson comorbidity index (CCI), and serum albumin level, 23 patients were selected for each group. Kaplan-Meier analysis showed a significantly lower cumulative survival rate in the LTBI group (p = 0.048, log-rank test). In the LTBI group, the cumulative survival rate tended to be higher in the LTBI-treated group (n = 13) than in the untreated group (n = 10) (p = 0.089).

CONCLUSION

Patients with LTBI at dialysis initiation have a poorer prognosis than those without LTBI, and LTBI treatment may improve their prognosis. This study emphasizes the clinical importance and necessity of managing LTBI in dialysis patients.

Impaired control of Mycobacterium tuberculosis infection in mast cell-deficient KitW-sh/W-sh mice

Tuberculosis (TB) is a global health problem with diverse clinical manifestations. Different cells of the immune response participate in containing the infection, mainly through the development of granulomas. Mast cells (MCs) are hematopoietic cells that participate in the immune response to different pathogens, and in vitro evidence indicates that they can be activated by Mycobacterium tuberculosis (Mtb). The aim of this study was to evaluate the role of MCs in a murine TB model. We observed that KitW-sh/W-sh mast cell-deficient mice showed increased bacterial load in the lungs and the spleen compared to wild-type C57BL/6 mice. Furthermore, MC-deficient mice showed fewer pulmonary granulomas but an early higher inflammatory infiltrate. Interestingly, serum cytokine levels were altered in MC-deficient mice, which showed increased levels of IL-4, IL-5, and IL-22 during the early phase of the infection but increased levels of IFN-γ, IL-9, IL-10, and IL-21 during the late phase of the infection. These results show that mast cells play an important role during Mtb infection by modulating the immune response to the bacteria.

Innate Lymphoid Cells and Their Role in the Immune Response to Infections

Over the past decade, a group of lymphocyte-like cells called innate lymphoid cells (ILCs) has gained considerable attention due to their crucial role in regulating immunity and tissue homeostasis. ILCs, lacking antigen-specific receptors, are a group of functionally differentiated effector cells that act as tissue-resident sentinels against infections. Numerous studies have elucidated the characteristics of ILC subgroups, but the mechanisms controlling protective or pathological responses to pathogens still need to be better understood. This review summarizes the functions of ILCs in the immunology of infections caused by different intracellular and extracellular pathogens and discusses their possible therapeutic potential.

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.

IL-22 as a target for therapeutic intervention: Current knowledge on its role in various diseases

IL-22 has emerged as a crucial cytokine mediating protective response against pathogens and tissue regeneration. Dysregulated production of IL-22 has been shown to play a pivotal role in the pathogenesis of various diseases like malignant tumours, viral, cardiovascular, allergic and autoimmune disorders. Interleukin 22 belongs to IFN-IL-10 cytokine family. It is a major proinflammatory cytokine secreted by activated Th1 cells (Th22), though can also be secreted by many other immune cells like group 3 innate lymphocytes, γδ T cells, NK cells, NK T cells, and mucosal associated invariant T cells. Th22 cells exclusively release IL-22 but not IL-17 or IFN-γ (as Th1 cells releases IFN-γ along with IL-22 and Th17 cells releases IL-17 along with IL-22) and also express aryl hydrocarbon receptor as the key transcription factor. Th22 cells also exhibit expression of chemokine receptor CCR6 and skin-homing receptors CCR4 and CCR10 indicating the involvement of this subset in bolstering epithelial barrier immunity and promoting secretion of antimicrobial peptides (AMPs) from intestinal epithelial cells. The function of IL-22 is modulated by IL-22 binding protein (binds to IL-22 and inhibits it binding to its cell surface receptor); which serves as a competitor for IL-22R1 chain of IL-22 receptor. The pathogenic and protective nature of the Th22 cells is modulated both by the site of infected tissue and the type of disease pathology. This review aims to discuss key features of IL-22 biology, comparisons between IL and 22 and IFN-γ and its role as a potential immune therapy target in different maladies.

Latent tuberculosis is associated with heightened levels of pro-and anti-inflammatory cytokines among Kenyan men and women living with HIV on long-term antiretroviral therapy

BACKGROUND

Persons with HIV (PWH) on antiretroviral therapy (ART) have persistent immune activation associated with increased risk for non-AIDS related diseases. Latent tuberculosis infection (LTBI), endemic in Africa, may contribute to this immune dysregulation. We evaluated the impact of HIV and TB co-infection on plasma pro- and anti-inflammatory cytokines among Kenyan adults.

METHODS

We compared data from 221 PWH on long-term ART and 177 HIV-negative adults examining biomarkers of pro-[sCD14, interleukin (IL)-2, IL-6, interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), IL-12p70, IL-17A] and anti(IL-4, IL-5, IL-13) inflammatory cytokines, by HIV/LTBI status (HIV+LTBI+, HIV+LTBI-, HIV-LTBI+, HIV-LTBI-). LTBI was diagnosed based on a positive QuantiFERON TB Gold-Plus test in the absence of active TB symptoms. Linear regression was used to evaluate the associations of HIV, LTBI, and HIV/LTBI status with biomarkers adjusting for clinical factors including HIV-specific factors.

RESULTS

Half of the participants were women and 52% had LTBI. HIV was independently associated with higher sCD14, IL-15, IL-6, IL-4, IL-5. LTBI was independently associated with higher TNF-α, IL-12p70, IL-17A, IL-4, IL-13 in adjusted models ( P  < 0.05). LTBI status was associated with higher IL-4 and IL-12p70 only among PWH, but not HIV-negative participants ( P  < 0.05 for interactions). In multivariate analysis, only HIV+LTBI+ demonstrated elevated levels of TNF-α, IL-6, IL-12p70, IL-15, IL-17A, IL4, IL-5, IL-13 in comparison to the HIV-LTBI- ( P  < 0.05 for all). The effect of LTBI on cytokines among PWH was independent of CD4 + T-cell count and ART duration.

CONCLUSIONS

Despite viral suppression, persons with HIV and LTBI exhibit abnormal cytokine production accompanied by high concentrations of pro- and anti-inflammatory cytokines.

Exploring the link between cardiovascular risk factors and manifestations in latent tuberculosis infection: a comprehensive literature review

BACKGROUND

The global burden of tuberculosis (TB) and cardiovascular disease (CVD) is overt, and the prevalence of this double burden disease remains steadily rising, particularly in low- and middle-income countries. This review aims to explore the association between latent tuberculosis infection (LTBI) and the development of cardiovascular diseases and risk factors. Furthermore, we elucidated the underlying pathophysiological mechanisms that contribute to this relationship.

MAIN BODY

Approximately 25% of the global population carries a dormant form of tuberculosis (TB) infection. During this latent stage, certain subsets of mycobacteria actively reproduce, and recent research suggests that latent TB infection (LTBI) is connected to persistent, long-term low-grade inflammation that can potentially contribute to the development of atherosclerosis and cardiovascular disease (CVD). The presence of LTBI can be confirmed through a positive result on either a tuberculin skin test (TST) or an interferon-gamma release assay (IGRA). Several plausible explanations for the association between LTBI and CVD include increased inflammation, autoimmunity related to heat shock proteins (HSP), and the presence of pathogens within the developing atherosclerotic plaque. The most commonly observed cardiovascular events and risk factors associated with LTBI are acute myocardial infarction, coronary artery stenosis, diabetes mellitus, and hypertension.

CONCLUSIONS

This article highlights the critical role of LTBI in perpetuating the tuberculosis disease cycle and its association with cardiovascular risk factors. Chronic and persistent low inflammation underlined the association. Identifying high-risk LTBI patients and providing targeted preventive medication are crucial strategies for global TB eradication and interrupting transmission chains.

Mycobacterium potentiates protection from colorectal cancer by gut microbial alterations

Not only are many Mycobacteria pathogens, but they can act as strong non-specific immunopotentiators, generating beneficial effects on the pathogenesis of some diseases. However, there has been no direct evidence of the effect of mycobacterial species on colorectal cancer (CRC). Herein, we showed that there may be a meaningful inverse correlation between the incidence of tuberculosis and CRC based on global statistics and that heat-killed Mycobacterial tuberculosis and live Mycobacterium bovis (Bacillus Calmette-Guérin strain) could ameliorate CRC development. In particular, using a faecal microbiota transplantation and a comparison between separate housing and cohousing, we demonstrated that the gut microbiota is involved in the protective effects. The microbial alterations can be elucidated by the modulation of antimicrobial activities including those of the Reg3 family genes. Furthermore, interleukin-22 production by T helper cells contributed to the anti-inflammatory activity of Mycobacteria. Our results revealed a novel role of Mycobacteria involving gut microbial alterations in dampening inflammation-associated CRC and an immunological mechanism underlying the interaction between microbes and host immunity.

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.

Innate lymphoid cells exhibited IL-17-expressing phenotype in active tuberculosis disease

BACKGROUND

Innate lymphoid cells (ILCs), as an important group of innate immunity, could respond rapidly to Mycobacterium tuberculosis (Mtb) infection. In this research, we studied the phenotypic changes of circulatory ILCs in active tuberculosis (TB) disease.

METHODS

We recruited 40 patients with active Mtb infection (TB group) and 41 healthy subjects (NC group), and collected their clinical information and peripheral blood. Circulating ILCs, ILC subsets, dendritic cells (DCs), macrophages, and the production of cytokines in ILCs were tested by flow cytometry (FCM). Enzyme-linked immunosorbent assay (ELISA) was used to detect plasma IL-23.

RESULTS

Compared with healthy control, total ILCs (0.73% vs. 0.42%, P = 0.0019), ILC1 (0.55% vs. 0.31%, P = 0.0024) and CD117⁺ ILC2 (0.02% vs. 0.01%, P = 0.0267) were upregulated in TB group. The total IL-17⁺ lymphocytes were elevated (3.83% vs. 1.76%, P = 0.0006) while the IL-22⁺ lymphocytes remained unchanged. Within ILC subsets, ILC3, CD117⁺ ILC2 and ILC1 in TB group all expressed increased IL-17 (15.15% vs. 4.55%, 19.01% vs. 4.57%, 8.79% vs. 3.87%, P < 0.0001) but similar IL-22 comparing with healthy control. TB group had more plasma IL-23 than NC group (7.551 vs. 5.564 pg/mL, P = 0.0557). Plasma IL-23 in TB group was positively correlated to IL-17⁺ ILC3 (r = 0.4435, P = 0.0141), IL-17⁺CD117⁺ ILC2 (r = 0.5385, P = 0.0021) and IL-17⁺ ILC1(r = 0.3719, P = 0.0430). TB group also had elevated DCs (9.35% vs. 6.49%, P < 0.0001) while macrophages remained unchanged. Within TB group, higher proportion of IL-17⁺ ILCs was related to severer inflammatory status and poorer clinical condition.

CONCLUSIONS

In active TB disease, circulatory ILCs were upregulated and exhibited IL-17-expressing phenotype. This may expand the understanding of immune reaction to Mtb infection.

Characterization of membrane-bound IL-22+ T cell subsets in HIV-1 patients coinfected with Mycobacterium tuberculosis

BACKGROUND

Previously, we have found that IL-22 could be not only secreted outside of cells, but also highly expressed on the T cells membrane in HIV-1 negative patients with tuberculosis (TB). However, the study on membrane-bound IL-22+ cells of HIV-1 infected patients is rare. Therefore, we investigated antigen-specific membrane-bound IL-22+ T cell subsets in Mycobacterium tuberculosis (M.tb) coinfection of HIV-1 infected individuals.

METHODS

A case-control study that enrolled 74 HIV-1 infected participants was carried out, including HIV-1 monoinfection (HIV+TB-, n = 43), HIV-1 infected patients with latent TB (HIV+LTB, n = 18) and HIV-1 coinfected patients with active TB (HIV+TB+, n = 13). We made use of an IFN-γ release assay (IGRA) to screen LTB individuals. Purified protein derivative (PPD) and phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) were used as specific-stimulators to detect the levels of peripheral blood membrane-bound IL-22+ T cell subsets via cell surface staining and flow cytometry among three groups.

RESULTS

An approximate rate of 24.3% (n = 18 out of 74) of latent M.tb infection among HIV-1 positive population in Eastern China. Interestingly, HMBPP-specific CD3+Vγ2+ T cells were impaired in HIV+TB+patients compared with HIV+LTB patients (P < 0.05). Furthermore, increases of PPD-specific and HMBPP-specific membrane-bound IL-22+ T cell subsets including CD3+, CD3+CD4+ and CD3+Vγ2+ T cells were observed in HIV+TB+group rather than HIV+LTB groups (all P < 0.05).

CONCLUSION

Antigen-specific membrane-bound IL-22+ T cells were highly expressed in M.tb coinfection of HIV-1 infected individuals, and may play an important role in anti-TB immune response during coinfection with HIV-1.

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

The role of interleukin-22 (IL-22) in the pathogenesis or tissue repair in human tuberculosis (TB) remains to be established. Here, we aimed to explore the ex-vivo and in-vitro T helper 22 (Th22) response in TB patients and healthy donors (HD) induced by different local multi-drug-resistant (MDR) Mvcobacterium tuberculosis (Mtb) strains. For this purpose, peripheral blood mononuclear cells from drug-susceptible (S-TB) MDR-TB patients and HD were stimulated with local MDR strains and the laboratory strain H37Rv. IL-22 and IL-17 expression and senescent status were assessed in CD4+ and CD8+ cells by flow cytometry, while IL-22 amount was measured in plasma and culture supernatants by enzyme-linked immunosorbent assay (ELISA). We found lower IL-22 amounts in plasma from TB patients than HD, together with a decrease in the number of circulating T cells expressing IL-22. In a similar manner, all Mtb strains enhanced IL-22 secretion and expanded IL-22+ cells within CD4+ and CD8+ subsets, being the highest levels detected in S-TB patients. In MDR-TB, low systemic and Mtb-induced Th22 responses associated with high sputum bacillary load and bilateralism of lung lesions, suggesting that Th22 response could be influencing the ability of MDR-TB patients to control bacillary growth and tissue damage. In addition, in MDR-TB patients we observed that the higher the percentage of IL-22+ cells, the lower the proportion of programmed cell death 1 (PD-1)+ or CD57+ T cells. Furthermore, the highest proportion of senescent T cells was associated with severe lung lesions and bacillary load. Thus, T cell senescence would markedly influence Th22 response mounted by MDR-TB patients.

Systemic Inflammation in Pregnant Women With Latent Tuberculosis Infection

Background

Recent studies in adults have characterized differences in systemic inflammation between adults with and without latent tuberculosis infection (LTBI+ vs. LTBI−). Potential differences in systemic inflammation by LTBI status has not been assess in pregnant women.

Methods

We conducted a cohort study of 155 LTBI+ and 65 LTBI− pregnant women, stratified by HIV status, attending an antenatal clinic in Pune, India. LTBI status was assessed by interferon gamma release assay. Plasma was used to measure systemic inflammation markers using immunoassays: IFNβ, CRP, AGP, I-FABP, IFNγ, IL-1β, soluble CD14 (sCD14), sCD163, TNF, IL-6, IL-17a and IL-13. Linear regression models were fit to test the association of LTBI status with each inflammation marker. We also conducted an exploratory analysis using logistic regression to test the association of inflammatory markers with TB progression.

Results

Study population was a median age of 23 (Interquartile range: 21–27), 28% undernourished (mid-upper arm circumference (MUAC) <23 cm), 12% were vegetarian, 10% with gestational diabetes and 32% with HIV. In multivariable models, LTBI+ women had significantly lower levels of third trimester AGP, IL1β, sCD163, IL-6 and IL-17a. Interestingly, in exploratory analysis, LTBI+ TB progressors had significantly higher levels of IL1β, IL-6 and IL-13 in multivariable models compared to LTBI+ non-progressors.

Conclusions

Our data shows a distinct systemic immune profile in LTBI+ pregnant women compared to LTBI− women. Data from our exploratory analysis suggest that LTBI+ TB progressors do not have this immune profile, suggesting negative association of this profile with TB progression. If other studies confirm these differences by LTBI status and show a causal relationship with TB progression, this immune profile could identify subsets of LTBI+ pregnant women at high risk for TB progression and who can be targeted for preventative therapy.

Depression and recovery of IL-17A secretion in mitogen responses in patients with active tuberculosis-a prospective observational study

BACKGROUND/PURPOSE

T-helper cell 17 (Th17) is a distinct subset of CD4+ T lymphocytes that is important in the pathogenesis of Mycobacterium tuberculosis infection. This study aims to investigate the characteristics of interleukin (IL)-17A and Th17-related cytokines after stimulation with phytohemagglutinin in patients with active tuberculosis (TB).

METHODS

This prospective cohort study enrolled patients with culture-confirmed active TB. QuantiFERON-TB Gold In-Tube (QFT-GIT) assay was performed upon TB diagnosis and at 2 months after TB treatment. Their non-TB-specific secretion of IL-17A and Th17-related cytokines were measured in supernatants of mitogen tubes in QFT-GIT and compared to those of active TB contacts with or without latent TB infection. We analyzed the association between IL-17A secretions and TB presentation and treatment outcomes.

RESULTS

A total of 108 patients with TB and 64 non-TB cases were enrolled. The secretion of IL-17A, IL-21, IL-23, and IL-6 were lower in active TB patients upon TB diagnosis. In active TB patients, lower IL-17A secretions were associated with higher grades of sputum smear. In the multivariate analysis, lower IL-17A secretions served as an independent factor associated with 2-month culture non-conversion (odds ratio 23.04, 95% confidence interval [CI] 1.69-84.78) and on-treatment mortality (hazard ratio 28.54, 95% CI 1.30-99.25). The levels of IL-23, and IL-6 significantly increased after 2 months of anti-TB treatment.

CONCLUSION

The non-TB-specific IL-17A secretions were lower in active TB patients upon TB diagnosis and associated with higher disease severity and worse treatment outcomes. Trend of recovery of the depressed Th17-related cytokines was noted after effective anti-TB treatment.

Characterization of cytokine profile to distinguish latent tuberculosis from active tuberculosis and healthy controls

BACKGROUND

Tuberculosis (TB) is an infectious disease and its mortality rate ranks first. Latent tuberculosis infection (LTBI) means that a patient is infected with Mycobacterium tuberculosis, but has no relative clinical symptoms. It has been estimated that approximately 10% of patients with LTBI would develop into active tuberculosis. Therefore, it was urgent to search for more efficient biomarkers to discriminate LTBI from healthy population.

METHODS

The Luminex assay was employed to detect the quantity of cytokines secreted by mononuclear cells from peripheral blood stimulated with the ESAT6 protein among TB, LTBI and healthy controls. The cytokine profile was analyzed by principal components analysis and the receiver operating characteristic curve analysis.

RESULTS

The principal components analysis indicated that LTBI and TB were clearly separated from healthy controls, and that LTBI was also successfully differentiated from healthy controls. The cytokine profiling method to distinguish LTBI from healthy controls has a sensitivity and specificity of 100%. Nine potential biomarkers, including IL-23, IL-21, HGF, Bngf, IL-27, IL-31, IL-1β, IL-22 and IL-18, were identified, and these cytokines were considered as a potential cytokine complex for more effectively discriminating LTBI from healthy controls.

CONCLUSION

IL-23, IL-21, HGF, Bngf, IL-27, IL-31, IL-1β, IL-22 and IL-18 were demonstrated to be the potential cytokine complex for the assessment between LTBI and healthy controls.

Characterization of concurrent target suppression by JNJ-61178104, a bispecific antibody against human tumor necrosis factor and interleukin-17A

Tumor necrosis factor (TNF) and interleukin (IL)-17A are pleiotropic cytokines implicated in the pathogenesis of several autoimmune diseases including rheumatoid arthritis (RA) and psoriatic arthritis (PsA). JNJ-61178104 is a novel human anti-TNF and anti-IL-17A monovalent, bispecific antibody that binds to both human TNF and human IL-17A with high affinities and blocks the binding of TNF and IL-17A to their receptors in vitro. JNJ-61178104 also potently neutralizes TNF and IL-17A-mediated downstream effects in multiple cell-based assays. In vivo, treatment with JNJ-61178104 resulted in dose-dependent inhibition of cellular influx in a human IL-17A/TNF-induced murine lung neutrophilia model and the inhibitory effects of JNJ-61178104 were more potent than the treatment with bivalent parental anti-TNF or anti-IL-17A antibodies. JNJ-61178104 was shown to engage its targets, TNF and IL-17A, in systemic circulation measured as drug/target complex formation in normal cynomolgus monkeys (cyno). Surprisingly, quantitative target engagement assessment suggested lower apparent in vivo target-binding affinities for JNJ-61178104 compared to its bivalent parental antibodies, despite their similar in vitro target-binding affinities. The target engagement profiles of JNJ-61178104 in humans were in general agreement with the predicted profiles based on cyno data, suggesting similar differences in the apparent in vivo target-binding affinities. These findings show that in vivo target engagement of monovalent bispecific antibody does not necessarily recapitulate that of the molar-equivalent dose of its bivalent parental antibody. Our results also offer valuable insights into the understanding of the pharmacokinetics/pharmacodynamics and target engagement of other bispecific biologics against dimeric and/or trimeric soluble targets in vivo.

The immunopathogenesis of tuberculous pericarditis

Tuberculous pericarditis is a severe form of extrapulmonary tuberculosis and is the commonest cause of pericardial effusion in high incidence settings. Mortality ranges between 8 and 34%, and it is the leading cause of pericardial constriction in Africa and Asia. Current understanding of the disease is based on models derived from studies performed in the 1940-50s. This review summarises recent advances in the histology, microbiology and immunology of tuberculous pericarditis, with special focus on the effect of Human Immunodeficiency Virus (HIV) and the determinants of constriction.

IL-22: An Underestimated Player in Natural Resistance to Tuberculosis?

Approximately 10% of individuals latently infected with Mycobacterium tuberculosis (Mtb) develop active tuberculosis (TB) during their lifetime. Although it is well recognized that T-helper 1 immune responses are crucial for containing latent TB infection, the full array of host factors conferring protective immunity from TB progression are not completely understood. IL-22 is produced by cells of the innate and adaptive immune system including innate lymphoid cells, and natural killer cells as well as T lymphocytes (Th1, Th17, and Th22) and binds to its cognate receptor, the IL-22R1, which is expressed on non-hematopoietic cells such as lung epithelial cells. However, recent studies suggest that Mtb induces expression of the IL-22R1 on infected macrophages and multiple studies have indicated a protective role of IL-22 in respiratory tract infections. Reduced concentrations of circulating IL-22 in active TB compared to latent TB and decreased percentages of Mtb-specific IL-22 producing T cells in TB patients compared to controls designate this cytokine as a key player in TB immunology. More recently, it has been shown that in type 2 diabetes (T2D) and TB co-morbidity serum IL-22 concentrations are further reduced compared to TB patients without co-morbidities. However, whether a causative link between low IL-22 and increased susceptibility to TB and disease severity of TB exists remains to be established. This review summarizes the contribution of IL-22, a potentially under-appreciated key player in natural resistance to TB, at the interface between the immune response to Mtb and the lung epithelium.

Latent tuberculosis infection is associated with increased unstimulated levels of interferon-gamma in Lima, Peru

Background

We previously reported increased unstimulated blood levels of interferon-gamma in persons with latent tuberculosis infection (LTBI) in the United States, suggesting enhanced immune activation in LTBI. To investigate this further in a TB-endemic setting, we assessed interferon-gamma levels in persons with and without LTBI in Peru.

Methods

We analyzed data from patients with and without a recent type 1 (spontaneous) acute myocardial infarction (AMI) who were enrolled from two public hospital networks in Lima, Peru, and underwent LTBI testing using the QuantiFERON® TB Gold In-tube (QFT) assay. Participants with a positive QFT test were defined as having LTBI, whereas participants with a negative QFT test were defined as non-LTBI. Unstimulated interferon-gamma was quantified via enzyme-linked immunosorbent assay in the QFT nil-tube, which does not contain antigens. We compared unstimulated interferon-gamma levels between LTBI and non-LTBI groups using the Wilcoxon rank sum test. We used proportional odds modeling for multivariable analysis.

Results

Data from 214 participants were included in this analysis. Of those, 120 (56%) had LTBI. There were no significant differences in age, sex and comorbidities between LTBI and non-LTBI participants, except for recent AMI that was more frequent in LTBI. LTBI participants had higher unstimulated interferon-gamma levels compared to non-LTBI participants (median, interquartile range; 14 pg/mL, 6.5–52.8 vs. 6.5 pg/mL, 4.5–15; P<0.01). LTBI remained associated with higher unstimulated interferon-gamma levels after controlling for age, sex, recent AMI, history of hypertension, diabetes mellitus, dyslipidemia, end stage renal disease, malignancy, obesity, and tobacco use (adjusted odds ratio, 2.93; 95% confidence interval, 1.8–4.9). In a sensitivity analysis that excluded participants with AMI, the association between unstimulated interferon-gamma and LTBI remained present (adjusted odds ratio; 3.93; 95% confidence interval, 1.9–8.2).

Conclusions

LTBI was associated with higher unstimulated interferon-gamma levels. These data suggest ongoing immune activation in LTBI.

Characterization of immune responses of human PBMCs infected with Mycobacterium tuberculosis H37Ra: Impact of donor declared BCG vaccination history on immune responses and M. tuberculosis growth

This study characterized the immune responses in early Mycobacterium tuberculosis (Mtb) H37Ra infection of human peripheral blood mononuclear cell (PBMC)-collagen matrix culture and the impact of Bacille Calmette-Guérin (BCG) vaccination history of donor PBMCs on the immune responses to Mtb infection. Aggregates of PBMCs were initially observed on day 3 and the size of aggregates continued to increase on day 8 post-infection, where macrophages and T cell subsets were identified to be present. Similarly, mycobacterial load progressively increased in infected PBMCs during the 8 days of culture but were significantly lower in infected PBMCs from BCG vaccinated (BCG+) donors compared to unvaccinated (BCG-) donors. The levels of INF-γ, TNF-α, IL-4, IL-6, IL-10 and IL-17 in the supernatants of Mtb-infected PBMCs peaked at day 3 and decreased on days 5 and 8. The levels of these cytokines except IL-10 were significantly lower in Mtb-infected PBMCs from BCG+ donors compared to infected PBMCs from BCG- donors. The percentages of activated naïve Th cells, activated effector memory Th cells and activated central memory Tc cells were significantly higher in Mtb-infected PBMCs compared to uninfected PBMCs at day 8 post-infection. Further, the proportion of activated central memory Tc cells was significantly higher in infected PBMCs from BCG+ donors compared to the BCG- donors. This study highlights the possibility that BCG vaccination may confound results that utilize human PBMCs to study Mtb infection.

Characterization of αβ and γδ T cell subsets expressing IL-17A in ruminants and swine

As part of our ongoing program to expand immunological reagents available for research in cattle, we developed a monoclonal antibody (mAb) to bovine interleukin-17A (IL-17A), a multifunctional cytokine centrally involved in regulating innate and adaptive immune responses. Initial comparative studies demonstrated the mAb recognizes a conserved epitope expressed on orthologues of IL-17A in sheep, goats and pigs. Comparative flow cytometric analyses of lymphocyte subsets stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin revealed differences in expression of IL-17A by CD4, CD8, and γδ T cells across ruminants and swine species. Results in cattle showed the largest proportion of IL-17A⁺ cells were CD4⁺ followed by γδ and CD8⁺ T cells. Further analysis revealed the IL-17A⁺ γδ T cell subset was comprised of WC1.1⁺, WC1.2⁺, and WC1^- subsets. Analysis of the IL-17A⁺ CD8⁺ T cell subset revealed it was comprised of αβ and γδ T cell subsets. Results in sheep and goats revealed IL-17A is expressed mainly by CD4⁺ and CD8⁺ T cells, with little expression by γδ T cells. Analysis of IL-17A⁺ CD8⁺ T cells showed the majority were CD8⁺ αβ in sheep, whereas they were CD8⁺ γδ in goats. The majority of the sheep and goat IL-17A⁺ γδ T cells were WC1⁺. Results obtained in swine showed expression of IL-17A by CD4, CD8, and γδ T cell subsets were similar to results reported in other studies. Comparison of expression of IL-17A with IFN-γ revealed subsets co-expressed IL-17A and IFN-γ in cattle, sheep, and goats. The new mAb expands opportunities for immunology research in ruminants and swine.

Interleukin-17 promotes metastasis in an immunocompetent orthotopic mouse model of prostate cancer

Metastasis of prostate cancer causes substantial morbidity and mortality. The role of chronic inflammatory factors in promoting the development of prostate cancer metastasis remains unexamined due to a lack of immunocompetent animal models. Here we report an orthotopic mouse allograft model of prostate cancer that was used to assess interleukin-17's role in prostate cancer metastasis. A luciferase gene was stably introduced into a mouse prostate cancer cell line MPC3, named as MPC3-luc. MPC3-luc cells were mixed with Matrigel™ and inoculated into C57BL/6 mouse prostates, with recombinant mouse interleukin-17 (IL-17) (treatment group) or without IL-17 (control group). Bioluminescent imaging was used to track the growth and metastasis of prostate cancer metastasis. Immunohistochemistry was performed to confirm metastasis. Mice in the IL-17 treatment group had significantly higher incidence of metastasis than mice in the control group. However, there was no detectable difference in primary prostate tumor growth. Metastases were confirmed as originating from prostate cancer through staining for luciferase protein expression. Our findings suggest that interleukin-17 promotes prostate cancer metastasis in an orthotopic mouse allograft model.

The Relationship Between Latent Tuberculosis Infection and Acute Myocardial Infarction

Background

Tuberculosis has been associated with an increased risk of cardiovascular disease (CVD), including acute myocardial infarction (AMI). We investigated whether latent tuberculosis infection (LTBI) is associated with AMI.

Methods

We conducted a case-control study in 2 large national public hospital networks in Lima, Peru, between July 2015 and March 2017. Case patients were patients with a first time diagnosis of type 1 (spontaneous) AMI. Controls were patients without a history of AMI. We excluded patients with known human immunodeficiency virus infection, tuberculosis disease, or prior LTBI treatment. We used the QuantiFERON-TB Gold In-Tube assay to identify LTBI. We used logistic regression modeling to estimate the odds ratio (OR) of LTBI in AMI case patients versus non-AMI controls.

Results

We enrolled 105 AMI case patients and 110 non-AMI controls during the study period. Overall, the median age was 62 years (interquartile range, 56-70 years); 69% of patients were male; 64% had hypertension, 40% dyslipidemia, and 39% diabetes mellitus; 30% used tobacco; and 24% were obese. AMI case patients were more likely than controls to be male (80% vs 59%; P < .01) and tobacco users (41% vs 20%; P < .01). LTBI was more frequent in AMI case patients than in controls (64% vs 49% [P = .03]; OR, 1.86; 95% confidence interval [CI], 1.08-3.22). After adjustment for age, sex, hypertension, dyslipidemia, diabetes mellitus, tobacco use, obesity, and family history of coronary artery disease, LTBI remained independently associated with AMI (adjusted OR, 1.90; 95% CI, 1.05-3.45).

Conclusions

LTBI was independently associated with AMI. Our results suggest a potentially important role of LTBI in CVD.

Levels of circulating cortisol and cytokines in members of the Canadian Armed Forces: associations with age, sex, and anthropometry

This study assessed blood levels of cortisol and cytokines (inflammatory and non-inflammatory) in members of the regular Canadian Armed Forces (CAF), and examined the associations between sex, age, and adiposity and circulating levels of cortisol as well as pro- and anti-inflammatory cytokines. As part of a larger ranging project, 331 blood samples were collected from a representative population of the total CAF, which included officers and noncommissioned women and men from the Air Force, Navy, and Army. The blood samples were analyzed for levels of cortisol, C-reactive protein (CRP), adiponectin, and 20 cytokines (which included interleukins, interferons, and tumor necrosis factors). Higher levels of adiponectin were found in women compared with men (median and interquartile range; 16.71 (7.68-25.32) vs 5.81 (3.52-13.19) μg/mL), and higher levels of interleukin (IL)-18 in men compared with women (89.25 (84.03-94.48) vs 75.91 (69.70-82.13) pg/mL). An association between age and levels of stress and inflammatory cytokines was observed, with CRP, IL-18, IL-2 and adiponectin all increasing with increasing age. However, contrary to trends seen in the general population, cortisol levels decreased with increasing age. Levels of CRP and IL-18 increased with an increase in adiposity, while adiponectin levels decreased. Most importantly, at the entire cohort level, a low detection rate for most of the cytokines was observed with 17 out of 22 cytokines having a detection below 10%.

IN CONCLUSION

In this CAF population, although an association between age and inflammatory cytokines was observed, both sex and adiposity had a small impact on levels of cortisol and cytokines.

The crucial roles of Th17-related cytokines/signal pathways in M. tuberculosis infection

Interleukin-17 (IL-17), IL-21, IL-22 and IL-23 can be grouped as T helper 17 (Th17)-related cytokines because they are either produced by Th17/Th22 cells or involved in their development. Here, we review Th17-related cytokines/Th17-like cells, networks/signals and their roles in immune responses or immunity against Mycobacterium tuberculosis (Mtb) infection. Published studies suggest that Th17-related cytokine pathways may be manipulated by Mtb microorganisms for their survival benefits in primary tuberculosis (TB). In addition, there is evidence that immune responses of the signal transducer and activator of transcription 3 (STAT3) signal pathway and Th17-like T-cell subsets are dysregulated or destroyed in patients with TB. Furthermore, Mtb infection can impact upstream cytokines in the STAT3 pathway of Th17-like responses. Based on these findings, we discuss the need for future studies and the rationale for targeting Th17-related cytokines/signals as a potential adjunctive treatment.

Novel role for IL-22 in protection during chronic Mycobacterium tuberculosis HN878 infection

Approximately 2 billion people are infected with Mycobacterium tuberculosis (Mtb), resulting in 1.4 million deaths every year. Among Mtb-infected individuals, clinical isolates belonging to the W-Beijing lineage are increasingly prevalent, associated with drug resistance, and cause severe disease immunopathology in animal models. Therefore, it is exceedingly important to identify the immune mechanisms that mediate protection against rapidly emerging Mtb strains, such as W-Beijing lineage. IL-22 is a member of the IL-10 family of cytokines with both protective and pathological functions at mucosal surfaces. Thus far, collective data show that IL-22 deficient mice are not more susceptible to aerosolized infection with less virulent Mtb strains. Thus, in this study we addressed the functional role for the IL-22 pathway in immunity to emerging Mtb isolates, using W-Beijing lineage member, Mtb HN878 as a prototype. We show that Mtb HN878 stimulates IL-22 production in TLR2 dependent manner and IL-22 mediates protective immunity during chronic stages of Mtb HN878 infection in mice. Interestingly, IL-22-dependent pathways in both epithelial cells and macrophages mediate protective mechanisms for Mtb HN878 control. Thus, our results project a new protective role for IL-22 in emerging Mtb infections.

Interactions between Type 1 Interferons and the Th17 Response in Tuberculosis: Lessons Learned from Autoimmune Diseases

The classical paradigm of tuberculosis (TB) immunity, with a central protective role for Th1 responses and IFN-γ-stimulated cellular responses, has been challenged by unsatisfactory results of vaccine strategies aimed at enhancing Th1 immunity. Moreover, preclinical TB models have shown that increasing IFN-γ responses in the lungs is more damaging to the host than to the pathogen. Type 1 interferon signaling and altered Th17 responses have also been associated with active TB, but their functional roles in TB pathogenesis remain to be established. These two host responses have been studied in more detail in autoimmune diseases (AID) and show functional interactions that are of potential interest in TB immunity. In this review, we first identify the role of type 1 interferons and Th17 immunity in TB, followed by an overview of interactions between these responses observed in systemic AID. We discuss (i) the effects of GM-CSF-secreting Th17.1 cells and type 1 interferons on CCR2⁺ monocytes; (ii) convergence of IL-17 and type 1 interferon signaling on stimulating B-cell activating factor production and the central role of neutrophils in this process; and (iii) synergy between IL-17 and type 1 interferons in the generation and function of tertiary lymphoid structures and the associated follicular helper T-cell responses. Evaluation of these autoimmune-related pathways in TB pathogenesis provides a new perspective on recent developments in TB research.

Elevated Circulating Concentrations of Interferon-Gamma in Latent Tuberculosis Infection

BACKGROUND

Latent tuberculosis infection (LTBI) has been associated with increased immune activation. We assessed circulating concentrations of interferon-gamma in persons with LTBI.

METHODS

We used the 2011-2012 National Health Nutritional Examination Survey (NHANES) to identify adults with and without LTBI by QuantiFERON®-TB Gold In-Tube (QFT) results. Non-LTBI persons were 1:1 age-, gender-, and race-matched to LTBI persons using propensity scores. We compared the plasma concentrations of interferon-gamma measured from the unstimulated, negative control QFT tube between LTBI and non-LTBI persons. We used Mann-Whitney tests and ordered logistic regressions for comparisons.

RESULTS

There were 430 LTBI and 430 non-LTBI matched persons included in the analysis. LTBI was associated with higher circulating concentrations of interferon-gamma (median, 3 pg/mL; IQR, 2 - 5) compared to non-LTBI (median, 2.5 pg/mL; IQR, 1.5 - 3.5); P < 0.001. LTBI remained associated with higher interferon-gamma concentrations after adjusting for age, gender, race, diabetes, hypertension, tobacco use, HIV status, body mass index, lipid profile, and lymphocyte count (odds ratio, 1.79, 95% CI, 1.26 - 2.53). Results remained similar when tuberculin skin testing defined LTBI.

CONCLUSIONS

LTBI was associated with increased circulating interferon-gamma concentrations. Future studies are needed to further characterize immune activation in LTBI and its potential long-term consequences.

Peripheral artery disease: epidemiology and global perspectives

Global populations are undergoing a major epidemiological transition in which the burden of atherosclerotic cardiovascular diseases is shifting rapidly from high-income to low-income and middle-income countries (LMICs). Peripheral artery disease (PAD) is no exception, so that greater focus is now required on the prevention and management of this disease in less-advantaged countries. In this Review, we examine the epidemiology of PAD and, where feasible, take a global perspective. However, the dearth of publications in LMICs means an unavoidable over-reliance on studies in high-income countries. Research to date suggests that PAD might affect a greater proportion of women than men in LMICs. Although factors such as poverty, industrialization, and infection might conceivably influence the development of PAD in such settings, the ageing of the population and increase in traditional cardiovascular risk factors, such as smoking, diabetes mellitus, and hypertension, are likely to be the main driving forces.

Serum interleukin-17 in Egyptian children with systemic lupus erythematosus: is it related to pulmonary affection?

Objective Pulmonary involvement in paediatric systemic lupus erythematosus (pSLE) is not an uncommon finding; however, subclinical affection occurs more frequently. Many studies have reported that cytokine dysregulation as interleukin-17 (IL-17) over-expression plays a key role in the pathogenesis of systemic lupus erythematosus (SLE). We aim to assess serum levels of IL-17 A and their association with pulmonary involvement in children with SLE. Methods Serum IL-17A levels - determined by solid phase sandwich ELISA - were assessed in forty-two pSLE patients and compared to 45 age-matched healthy controls. All patients were subjected to pulmonary function tests to detect subclinical pulmonary affection. High-resolution CT (HRCT) chest scan was carried out in patients with abnormal pulmonary function tests (PFTs) and those with chronic respiratory symptoms. Results Abnormal PFTs were found in 73% of patients; of them, only 25% had abnormal findings in HRCT chest. Serum levels of IL-17 A were significantly elevated in pSLE patients as compared to healthy controls ( p < 0.001). The serum levels of IL-17 A had a highly significant positive correlation with SLEDAI ( r = 0.811 and p < 0.001) Strong negative correlation was found between serum levels of IL-17A with both FEV1 and FVC ( p < 0.05). Conclusions Serum IL-17A is elevated in pSLE patients, which correlates with disease activity. IL-17 seems to have a possible role in the pathogenesis of subclinical lung affection. Abnormal PFTS may be found in pSLE patients even with normal radiology.

Evaluation of Interleukin17and Interleukin 23 expression in patients with active and latent tuberculosis infection

OBJECTIVES

Tuberculosis is one of the most important infectious diseases with high mortality rates worldwide, especially in developing countries. Interleukin17 (IL-17) is an important acquired immunity cytokine, which is mainly produced by CD4+TH17 cells. It can recruit neutrophils and macrophages to the infected site in the lungs. IL-23 is one of the most important inducers of IL-17. In the present study, the expressions of IL-23 and IL-17 were examined in the pathogenesis of tuberculosis.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from subjects with latent tuberculosis infection (LTB) and newly diagnosed active tuberculosis patients (ATB). PBMCs were activated with purified protein derivative (PPD) for 72 hr. Activated cells were harvested, RNA was extracted, and cDNA was synthesized. IL-17 and IL-23 mRNA expressions were evaluated by real-time PCR. The frequency of Th17 cells was examined by flowcytometry.

RESULTS

The expressions of IL-17 and IL-23 mRNA were lower in patients than subjects with LTB (P<0.05). The frequency of IL-17 producing CD4+ T cells in patients with active TB was lower than LTB subjects (P<0.05).

CONCLUSION

The results of the present study might suggest that IL-17 and IL-23 play critical roles in the immune response against TB.

The Role of Neutrophils in the Induction of Specific Th1 and Th17 during Vaccination against Tuberculosis

Mycobacterium tuberculosis causes tuberculosis (TB), a disease that killed more than 1.5 million people worldwide in 2014, and the Bacillus Calmette Guérin (BCG) vaccine is the only currently available vaccine against TB. However, it does not protect adults. Th1 and Th17 cells are crucial for TB control, as well as the neutrophils that are directly involved in DC trafficking to the draining lymph nodes and the activation of T lymphocytes during infection. Although several studies have shown the importance of neutrophils during M. tuberculosis infection, none have shown its role in the development of a specific response to a vaccine. The vaccine mc²-CMX was shown to protect mice against M. tuberculosis challenge, mainly due to specific Th1 and Th17 cells. This study evaluated the importance of neutrophils in the generation of the Th1- and Th17-specific responses elicited by this vaccine. The vaccine injection induced a neutrophil rich lesion with a necrotic central area. The IL-17 KO mice did not generate vaccine-specific Th1 cells. The vaccinated IL-22 KO mice exhibited Th1- and Th17-specific responses. Neutrophil depletion during vaccination abrogated the induction of Th1-specific responses and prohibited the bacterial load reduction observed in the vaccinated animals. The results show, for the first time, the role of neutrophils in the generation of specific Th1 and Th17 cells in response to a tuberculosis vaccine.

Evaluation of matricellular proteins in systemic and local immune response to Mycobacterium tuberculosis infection

Matricellular proteins such as osteopontin (OPN), galectin-9 (Gal-9), and tenascin-C (TN-C) are expressed not only under normal physiological conditions, but also during infection, inflammation and tumorigenesis. Plasma concentrations of matricellular proteins were studied to determine their diagnostic value as potential markers of tuberculosis (TB) activity. It was found that concentrations of OPN and TN-C were higher in patients with active TB than in healthy controls and individuals with latent infection. Moreover, LTBI patients had higher concentrations of OPN than did healthy controls. Gal-9 concentrations did not differ significantly between groups. Concentrations of matricellular proteins were higher in pleural fluid than in the plasma of patients with TB. Expression of matricellular proteins was also investigated in TB granulomas and other granulomatous diseases. Positive OPN and Gal-9 staining was observed in TB and sarcoidosis granulomas, but not in Crohn disease granulomas. The fibrotic ring around granulomas stained positive for TN-C in TB and sarcoidosis, but not in Crohn disease. Of the three matricellular proteins studied, OPN and TN-C may serve as reliable plasma markers for monitoring TB activity, whereas Gal-9 seems to be expressed more at the site of infection than in the systemic circulation.

Genome Sequencing and Annotation of Mycobacterium tuberculosis PR08 strain

Mycobacterium tuberculosis is an acid fast bacterial species in the family Mycobacteriaceae and is the causative agent of most cases of tuberculosis. Here, we report the genomic features of Mycobacterium tuberculosis isolated from the cerebrospinal fluid (CSF) of a patient diagnosed with both pulmonary and extrapulmonary tuberculosis (TB). The isolated strain was identified as Mycobacterium tuberculosis PR08 (MTB PR08). Genomic DNA of the MTB PR08 strain was extracted and subjected to whole genome sequencing using MiSeq (Illumina, CA,USA). The draft genome size of MTB PR08 strain is 4,292,364 bp with a G + C content of 65.2%. This strain was annotated to have 4723 genes and 48 RNAs. This whole genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number CP010895.

Postprimary Tuberculosis and Macrophage Necrosis: Is There a Big ConNECtion?

Adult or postprimary tuberculosis (TB) accounts for most TB cases. Its hallmark is pulmonary cavitation, which occurs as a result of necrosis in the lung in individuals with tuberculous pneumonia. Postprimary TB has previously been known to be associated with vascular thrombosis and delayed-type hypersensitivity, but their roles in pulmonary cavitation are unclear. A necrosis-associated extracellular cluster (NEC) refers to a cluster of drug-tolerant Mycobacterium tuberculosis attached to lysed host materials and is proposed to contribute to granulomatous TB. Here we suggest that NECs, perhaps due to big size, produce a distinct host response leading to postprimary TB. We propose that vascular thrombosis and pneumonia arise from NEC and that these processes are promoted by inflammatory cytokines produced from cell-mediated delayed-type hypersensitivity, such as interleukin-17 and gamma interferon, eventually triggering necrosis in the lung and causing cavitation. According to this view, targeting NEC represents a necessary strategy to control adult TB.

T cells and adaptive immunity to Mycobacterium tuberculosis in humans

The adaptive immune response mediated by T cells is critical for control of Mycobacterium tuberculosis (M. tuberculosis) infection in humans. However, the M. tuberculosis antigens and host T-cell responses that are required for an effective adaptive immune response to M. tuberculosis infection are yet to be defined. Here, we review recent findings on CD4(+) and CD8(+) T-cell responses to M. tuberculosis infection and examine the roles of distinct M. tuberculosis-specific T-cell subsets in control of de novo and latent M. tuberculosis infection, and in the evolution of T-cell immunity to M. tuberculosis in response to tuberculosis treatment. In addition, we discuss recent studies that elucidate aspects of M. tuberculosis-specific adaptive immunity during human immunodeficiency virus co-infection and summarize recent findings from vaccine trials that provide insight into effective adaptive immune responses to M. tuberculosis infection.

Tuberculosis and Cardiovascular Disease: Linking the Epidemics

The burden of tuberculosis and cardiovascular disease (CVD) is enormous worldwide. CVD rates are rapidly increasing in low- and middle-income countries. Public health programs have been challenged with the overlapping tuberculosis and CVD epidemics. Monocyte/macrophages, lymphocytes and cytokines involved in cellular mediated immune responses against Mycobacterium tuberculosis are also main drivers of atherogenesis, suggesting a potential pathogenic role of tuberculosis in CVD via mechanisms that have been described for other pathogens that establish chronic infection and latency. Studies have shown a pro-atherogenic effect of antibody-mediated responses against mycobacterial heat shock protein-65 through cross reaction with self-antigens in human vessels. Furthermore, subsets of mycobacteria actively replicate during latent tuberculosis infection (LTBI), and recent studies suggest that LTBI is associated with persistent chronic inflammation that may lead to CVD. Recent epidemiologic work has shown that the risk of CVD in persons who develop tuberculosis is higher than in persons without a history of tuberculosis, even several years after recovery from tuberculosis. Together, these data suggest that tuberculosis may play a role in the pathogenesis of CVD. Further research to investigate a potential link between tuberculosis and CVD is warranted.

Differential expression of CD57 in antigen-reactive CD4+ T cells between active and latent tuberculosis infection

The development of diagnostic tests that predict the progression of latent tuberculosis infection to active disease is pivotal for the eradication of tuberculosis. As an initial step to achieve this goal, our study's aim was to identify biomarkers that differentiate active from latent tuberculosis infection. We compared active and latent tuberculosis infection groups in terms of the precursor frequency, functional subset differentiation, and senescence/exhaustion surface marker expression of antigen-specific CD4(+) T cells, which were defined as dividing cells upon their encountering with Mycobacterium (M.) tuberculosis antigens. Among several parameters shown to have statistically significant differences between the two groups, the frequency of CD57-expressing cells could differentiate effectively between active disease and latent infection. Our results suggest that the expression of CD57 in M. tuberculosis-reactive CD4(+) T cells could be a promising candidate biomarker with which to identify individuals with latent tuberculosis infection prone to progression to active disease.

Directing traffic: IL-17 and IL-22 coordinate pulmonary immune defense

Respiratory infections and diseases are among the leading causes of death worldwide, and effective treatments probably require manipulating the inflammatory response to pathogenic microbes or allergens. Here, we review mechanisms controlling the production and functions of interleukin-17 (IL-17) and IL-22, cytokines that direct several aspects of lung immunity. Innate lymphocytes (γδ T cells, natural killer cells, innate lymphoid cells) are the major source of IL-17 and IL-22 during acute infections, while CD4(+) T-helper 17 (Th17) cells contribute to vaccine-induced immunity. The characterization of dendritic cell (DC) subsets has revealed their central roles in T-cell activation. CD11b(+) DCs stimulated with bacteria or fungi secrete IL-1β and IL-23, potent inducers of IL-17 and IL-22. On the other hand, recognition of viruses by plasmacytoid DCs inhibits IL-1β and IL-23 release, increasing susceptibility to bacterial superinfections. IL-17 and IL-22 primarily act on the lung epithelium, inducing antimicrobial proteins and neutrophil chemoattractants. Recent studies found that stimulation of macrophages and DCs with IL-17 also contributes to antibacterial immunity, while IL-22 promotes epithelial proliferation and repair following injury. Chronic diseases such as asthma and chronic obstructive pulmonary disease have been associated with IL-17 and IL-22 responses directed against innocuous antigens. Future studies will evaluate the therapeutic efficacy of targeting the IL-17/IL-22 pathway in pulmonary inflammation.

Anti-tuberculosis treatment enhances the production of IL-22 through reducing the frequencies of regulatory B cell

IL-22 has been suggested to play an important role in immune response against Mycobacterium tuberculosis infection. However, the exact role of IL-22 in human tuberculosis (TB) infection remains unclear and the regulatory mechanism of IL-22 response in human TB is unknown. In this study, we observed that successful anti-tuberculosis treatment induced an enhanced and sustained M. tuberculosis antigen-specific IL-22 response, correlated with the decrease of the frequencies of CD19(+)CD5(+)CD1d(+) regulatory B cells. We also found that depletion of CD19(+) B cells significantly enhanced M. tuberculosis antigen-specific IL-22 production by peripheral blood mononuclear cells. More importantly, we observed that purified CD19(+) B cells, and more efficiently, CD19(+)CD5(+)CD1d(+) regulatory B cells, suppressed IL-22 production. In summary, we showed here for the first time that effective anti-tuberculosis treatment restores M. tuberculosis antigen-specific IL-22 response through a novel mechanism by reducing the frequencies of CD19(+)CD5(+)CD1d(+) regulatory B cells in human TB.

Phosphorylated STAT3 and PD-1 regulate IL-17 production and IL-23 receptor expression in Mycobacterium tuberculosis infection

We studied the factors that regulate IL-23 receptor expression and IL-17 production in human tuberculosis infection. Mycobacterium tuberculosis (M. tb)-stimulated CD4(+) T cells from tuberculosis patients secreted less IL-17 than did CD4(+) T cells from healthy tuberculin reactors (PPD(+) ). M. tb-cultured monocytes from tuberculosis patients and PPD(+) donors expressed equal amounts of IL-23p19 mRNA and protein, suggesting that reduced IL-23 production is not responsible for decreased IL-17 production by tuberculosis patients. Freshly isolated and M. tb-stimulated CD4(+) T cells from tuberculosis patients had reduced IL-23 receptor and phosphorylated STAT3 (pSTAT3) expression, compared with cells from PPD(+) donors. STAT3 siRNA reduced IL-23 receptor expression and IL-17 production by CD4(+) T cells from PPD(+) donors. Tuberculosis patients had increased numbers of PD-1(+) T cells compared with healthy PPD(+) individuals. Anti-PD-1 antibody enhanced pSTAT3 and IL-23R expression and IL-17 production by M. tb-cultured CD4(+) T cells of tuberculosis patients. Anti-tuberculosis therapy decreased PD-1 expression, increased IL-17 and IFN-γ production and pSTAT3 and IL-23R expression. These findings demonstrate that increased PD-1 expression and decreased pSTAT3 expression reduce IL-23 receptor expression and IL-17 production by CD4(+) T cells of tuberculosis patients.