High interleukin-4 expression and interleukin-4 gene polymorphisms are associated with susceptibility to human paracoccidioidomycosis

IL-4 Predicts the Efficacy of a Candidate Antioxycodone Vaccine and Alters Vaccine-Specific Antibody-Secreting Cell Proliferation in Mice

Opioid use disorders (OUDs) are a public health concern in the United States and worldwide. Current medications for OUDs may trigger side effects and are often heavily regulated. A novel treatment strategy to be used alone or in combination with existing medications is active immunization with antiopioid vaccines, which stimulate production of opioid-specific Abs that bind to the target drug and prevent its distribution to the brain. Although antiopioid vaccines have shown promising preclinical efficacy, prior clinical evaluations of vaccines targeting stimulants indicate that efficacy is limited to a subset of subjects who achieve optimal Ab responses. We have previously reported that depletion of IL-4 with a mAb increased opioid-specific IgG2a and total IgG, and it increased the number of germinal centers and germinal center T follicular helper cells in response to antiopioid vaccines via type I IL-4 signaling. The current study further investigates the mechanisms associated with IL-4-mediated increases in efficacy and whether IL-4 depletion affects specific processes involved in germinal center formation, including affinity maturation, class switching, and plasma cell differentiation in mice. Additionally, results demonstrate that preimmunization production of IL-4 after ex vivo whole blood stimulation predicted in vivo vaccine-induced Ab titers in outbred mice. Such mechanistic studies are critical for rational design of next-generation vaccine formulations, and they support the use of IL-4 as a predictive biomarker in ongoing OUD vaccine clinical studies.

Genome-Wide Association Study Reveals CLEC7A and PROM1 as Potential Regulators of Paracoccidioides brasiliensis-Induction of Cytokine Production in Peripheral Blood Mononuclear Cells

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by fungi of the genus Paracoccidioides and the different clinical forms of the disease are associated with the host immune responses. Quantitative trait loci mapping analysis was performed to assess genetic variants associated with mononuclear-cells-derived cytokines induced by P. brasiliensis on 158 individuals. We identified the rs11053595 SNP, which is present in the CLEC7A gene (encodes the Dectin-1 receptor) and the rs62290169 SNP located in the PROM1 gene (encodes CD133) associated with the production of IL-1β and IL-22, respectively. Functionally, the blockade of the dectin-1 receptor abolished the IL-1β production in P. brasiliensis-stimulated PBMCs. Moreover, the rs62290169-GG genotype was associated with higher frequency of CD38+ Th1 cells in PBMCs cultured with P. brasiliensis yeasts. Therefore, our research indicates that the CLEC7A and PROM1 genes are important for the cytokine response induced by P. brasiliensis and may influence the Paracoccidioidomycosis disease outcome.

Paracoccidioidomycosis Protective Immunity

Protective immunity against Paracoccidioides consists of a stepwise activation of numerous effector mechanisms that comprise many cellular and soluble components. At the initial phase of non-specific innate immunity, resistance against Paracoccidioides comes from phagocytic polymorphonuclear neutrophils, natural killer (NK) cells and monocytes, supplemented by soluble factors such as cytokines and complement system components. Invariant receptors (Toll-like receptors (TLRs), Dectins) which are present in cells of the immune system, detect patterns present in Paracoccidioides (but not in the host) informing the hosts cells that there is an infection in progress, and that the acquired immunity must be activated. The role of components involved in the innate immunity of paracoccidioidomycosis is herein presented. Humoral immunity, represented by specific antibodies which control the fungi in the blood and body fluids, and its role in paracoccidioidomycosis (which was previously considered controversial) is also discussed. The protective mechanisms (involving various components) of cellular immunity are also discussed, covering topics such as: lysis by activated macrophages and cytotoxic T lymphocytes, the participation of lytic products, and the role of cytokines secreted by T helper lymphocytes in increasing the efficiency of Paracoccidioides, lysis.

Cytokine gene functional polymorphisms and phenotypic expression as predictors of evolution from latent to clinical rheumatic heart disease

INTRODUCTION

Inflammation associated with rheumatic heart disease (RHD) is influenced by gene polymorphisms and inflammatory cytokines. There are currently no immunologic and genetic markers to discriminate latent versus clinical patients, critical to predict disease evolution. Employing machine-learning, we searched for predictors that could discriminate latent versus clinical RHD, and eventually identify latent patients that may progress to clinical disease.

METHODS

A total of 212 individuals were included, 77 with latent, 100 with clinical RHD, and 35 healthy controls. Circulating levels of 27 soluble factors were evaluated using Bio-Plex ProTM® Human Cytokine Standard 27-plex assay. Gene polymorphism analyses were performed using RT-PCR for the following genes: IL2, IL4, IL6, IL10, IL17A, TNF and IL23.

RESULTS

Serum levels of all cytokines were higher in clinical as compared to latent RHD patients, and in those groups than in controls. IL-4, IL-8, IL-1RA, IL-9, CCL5 and PDGF emerged in the final multivariate model as predictive factors for clinical, compared with latent RHD. IL-4, IL-8 and IL1RA had the greater power to predict clinical RHD. In univariate analysis, polymorphisms in IL2 and IL4 were associated with clinical RHD and in the logistic analysis, IL6 (GG + CG), IL10 (CT + TT), IL2 (CA + AA) and IL4 (CC) genotypes were associated with RHD.

CONCLUSION

Despite higher levels of all cytokines in clinical RHD patients, IL-4, IL-8 and IL-1RA were the best predictors of clinical disease. An association of polymorphisms in IL2, IL4, IL6 and IL10 genes and clinical RHD was observed. Gene polymorphism and phenotypic expression of IL-4 accurately discriminate latent versus clinical RHD, potentially instructing clinical management.

Insulin Modulates Inflammatory Cytokine Release in Acute Stages and Augments Expression of Adhesion Molecules and Leukocytes in Lungs on Chronic Stages of Paracoccidioidomycosis

Type 1 diabetesmellitus (T1D) is caused by partial destruction of the insulin-producing beta cells in the pancreas and is a major issue for public health care worldwide. Reduced or impaired immunological responses, which render patients more susceptible to infections, have been observed in T1D, and this dysfunction is often related to a lack of insulin in the blood. Paracoccidioidomycosis is an important systemic mycosis endemic in Latin America. To evaluate the effects of T1D on this fungal infection and the modulatory effects of insulin, we induced diabetes in C57Bl/6 male mice (alloxan, 60 mg/kg), infected the mice (Pb18, 1 x 106 cells), and treated the mice with neutral protamine Hagedorn (NPH) insulin (2 IU/600 mg/dL blood glucose). Twenty-four hours after infection, infected diabetic mice showed reduced secretion of interferon (IFN)-γ and interleukine (IL)-12 p70 compared to infected nondiabetic controls. On the 45th day of infection, infected diabetic mice presented higher IFN-γ levels, a higher tumor necrosis factor (TNF)-α:IL-10 ratio, and lower adhesion molecule expression levels than nondiabetic mice. In the in vitro experiments, alveolar macrophages from diabetic animals showed reduced phagocytic activity compared to those from control animals at 4, 12, and 24 h. In infected diabetic mice, treatment with insulin restored IL-12 p70 levels at 24 h of infection, reduced IFN-γ levels and the TNF-α:IL-10 ratio at 45 days, and restored vascular cell adhesion molecule (VCAM)-1 expression in pulmonary blood vessels, and this treatment reduced the diminished phosphorylation of extracellular signal-regulated kinases (ERK) and increased nuclear factor-kappa-B(iκb)-α and jun amino-terminal kinases (JNK) p46 levels in infected nondiabetic mice. In addition, insulin promoted increased phagocytic activity in the alveolar macrophages of diabetic mice. These data suggest that T1D mice are more susceptible to Pb18 infection and that insulin modulates this inflammation in diabetic mice by augmenting the expression of adhesion molecules and leukocytes in the lungs and by reducing chronic inflammation.

Unraveling the susceptibility of paracoccidioidomycosis: Insights towards the pathogen-immune interplay and immunogenetics

Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis caused by Paracoccidioides spp. This disease comprises three clinical forms: symptomatic acute and chronic forms (PCM disease) and PCM infection, a latent form without clinical symptoms. PCM disease differs markedly according to severity, clinical manifestations, and host immune response. Fungal virulence factors and adhesion molecules are determinants for entry, latency, immune escape and invasion, and dissemination in the host. Neutrophils and macrophages play a paramount role in first-line defense against the fungus through the recognition of antigens by pattern recognition receptors (PRRs), activating their microbicidal machinery. Furthermore, the clinical outcome of the PCM is strongly associated with the variability of cytokines and immunoglobulins produced by T and B cells. While the mechanisms that mediate susceptibility or resistance to infection are dictated by the immune system, some genetic factors may alter gene expression and its final products and, hence, modulate how the organism responds to infection and injury. This review outlines the main findings relative to this topic, addressing the complexity of the immune response triggered by Paracoccidioides spp. infection from preclinical investigations to studies in humans. Here, we focus on mechanisms of fungal pathogenesis, the patterns of innate and adaptive immunity, and the genetic and molecular basis related to immune response and susceptibility to the development of the PCM and its clinical forms. Immunogenetic features such as HLA system, cytokines/cytokines receptors genes and other immune-related genes, and miRNAs are likewise discussed. Finally, we point out the occurrence of PCM in patients with primary immunodeficiencies and call attention to the research gaps and challenges faced by the PCM field.

Polymorphism in the Promoter Region of the IL18 Gene and the Association With Severity on Paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is an important endemic, systemic disease in Latin America caused by Paracoccidioides spp. This mycosis has been associated with high morbidity and sequels, and its clinical manifestations depend on the virulence of the infecting strain, the degree and type of immune response, infected tissues, and intrinsic characteristics of the host. The T helper(Th)1 and Th17/Th22 cells are related to resistance and control of infection, and a Th2/Th9 response is associated with disease susceptibility. In this study, we focused on interleukin(IL)-12p35 (IL12A), IL-18 (IL18), and IFN-γ receptor 1 (IFNGR1) genetic polymorphisms because their respective roles have been described in human PCM. Real-time PCR was employed to analyze IL12A-504 G/T (rs2243115), IL18-607 C/A (rs1946518), and IFNGR1-611 A/G (rs1327474) single nucleotide polymorphisms (SNP). One hundred forty-nine patients with the acute form (AF), multifocal chronic (MC), or unifocal chronic (UC) forms of PCM and 110 non-PCM individuals as a control group were included. In the unconditional logistic regression analysis adjusted by ethnicity and sex, we observed a high risk of the IL18-607 A-allele for both AF [p = 0.015; OR = 3.10 (95% CI: 1.24–7.77)] and MC groups [p = 0.023; OR = 2.61 (95% CI: 1.14–5.96)] when compared with UC. The IL18-607 A-allele associated risk for the AF and MC groups as well as the protective role of the C-allele in UC are possibly linked to higher levels of IL-18 at different periods of the course of the disease. Therefore, a novel role of IL18-607 C/A SNP is shown in the present study, highlighting its importance in the outcome of PCM.

Host-Pathogen Interactions in Coccidioidomycosis: Prognostic Clues and Opportunities for Novel Therapies

PURPOSE

Coccidioidomycosis (CM) is a systemic fungal disease caused by the dimorphic fungi Coccidioides immitis and Coccidioides posadasii. In its endemic areas of the United States, CM is growing as a public health challenge with a marked increase in incidence in the last 15 years. Although Coccidioides infection is asymptomatic in most cases, symptomatic pulmonary disease occurs in ~40% and disseminated coccidioidomycosis (DCM) occurs in ~1% of previously healthy children and adults. DCM is markedly more common in immunocompromised people, who often experience life-threatening disease despite use of antifungal medications. Although options for antifungal therapy have improved, lifelong therapy is needed for those who develop coccidioidal meningitis. The purpose of this article was to review the state of antifungal therapy and recent studies of host-pathogen interactions in CM in light of advances in immunomodulatory therapy.

METHODS

The study included a review of PubMed and abstracts of the Coccidioidomycosis Study Group (years 2000-2019).

FINDINGS

Current therapy for CM relies upon azole and polyene antifungal agents. Murine models and studies of DCM in patients with monogenic primary immunodeficiency states and acquired immunodeficiency have revealed the importance of both innate and adaptive immune responses in the control of infections with Coccidioides species. In particular, defects in sensing of fungi and induction of cellular immune responses have been frequently reported. More recently, polymorphisms in key signaling pathways and in the generation of Th17 and Th1 immune responses have been linked with DCM.

IMPLICATIONS

Antifungal therapy is sufficient to control disease in most cases of CM, but treatment failure occurs in cases of severe pulmonary disease and nonmeningeal disseminated disease. Lifelong therapy is recommended for meningitis in view of the very high risk of recurrence. Corticosteroid therapy is advised by some experts for severe pulmonary disease and for some neurologic complications of DCM. DCM is only rarely the result of a severe monogenic immunodeficiency. Case studies suggest that reorienting cellular immune responses or augmenting effector immune responses may help resolve DCM. Systematic investigation of immunotherapy for coccidioidomycosis is advisable and may help to address the recent marked increase in reports of the disease in endemic areas.

Regulation of neutrophils in type 2 immune responses

Type 2 immune responses contribute to the resistance to helminths and toxins as well as several physiological processes. Although they usually do not participate in type 2 immune responses, neutrophils have been shown in mice to enhance the anti-helminth response, but they also contribute to increased target tissue damage. Increased pathology and morbidity is also observed in type 2 immune-mediated disorders, such as allergic asthma, when neutrophils become a predominant subset of the infiltrate. How neutrophil recruitment is regulated during type 2 immune responses is now starting to become clear, with recent data showing that signaling via the prototypic type 2 cytokine interleukin-4 receptor mediates direct and indirect inhibitory actions on neutrophils in mice and humans.

Paracoccidioidomycosis: Current Perspectives from Brazil

BACKGROUND

This review article summarizes and updates the knowledge on paracoccidioidomycosis. P lutzii and the cryptic species of P. brasiliensis and their geographical distribution in Latin America, explaining the difficulties observed in the serological diagnosis.

OBJECTIVES

Emphasis has been placed on some genetic factors as predisposing condition for paracoccidioidomycosis. Veterinary aspects were focused, showing the wide distribution of infection among animals. The cell-mediated immunity was better characterized, incorporating the recent findings.

METHODS

Serological methods for diagnosis were also compared for their parameters of accuracy, including the analysis of relapse.

RESULTS

Clinical forms have been better classified in order to include the pictures less frequently observesiod.

CONCLUSION

Itraconazole and the trimethoprim-sulfamethoxazole combination was compared regarding efficacy, effectiveness and safety, demonstrating that azole should be the first choice in the treatment of paracoccidioidomycosis.

Polymorphisms on IFNG, IL12B and IL12RB1 genes and paracoccidioidomycosis in the Brazilian population

Paracoccidioidomycosis (PCM) is a systemic chronic mycosis, endemic in Latin America, especially Brazil, and is the eighth leading cause of death among chronic and recurrent infectious diseases. PCM infection is characterized by the presence of Th1 immune response; the acute form, by a mixed Th2/Th9, while the chronic form is characterized by Th17/Th22 profiles. The occurrence and severity of human PCM may also be associated with genetic factors such as single nucleotide polymorphisms (SNP) on cytokines encoding genes. We investigated the association between these polymorphisms and the different clinical forms of PCM. We included 156 patients with PCM (40 with the acute form, 99 with the chronic multifocal and 17 with the chronic unifocal form) and assayed their DNA samples for IFNG +874 T/A SNP by PCR-ARMS (Amplification Refractory Mutational System), IL12B +1188 A/C SNP on 3' UTR and IL12RB1 641 A/G SNP on exon 7 by PCR-RFLP (Restriction Fragment Length Polymorphism). We found similar genotypic and allelic frequencies of the investigated SNPs among the clinical forms of PCM. Considering male patients, the IL12RB1 641 AA genotype was more frequent in the chronic multifocal form while heterozygosis was in the chronic unifocal form of PCM (p=0.048). Although our data suggest that the AA genotype (IL12RB1) may be associated with the more disseminated chronic disease, more patients of the chronic unifocal PCM group need to be analyzed as well as the secretion patterns of IFN-γ combined with the IL-12Rβ1 expression for a better comprehension of this association.