BATF2 inhibits immunopathological Th17 responses by suppressing Il23a expression during Trypanosoma cruzi infection

Illuminating the pathogenic role of SARS-CoV-2: Insights into competing endogenous RNAs (ceRNAs) regulatory networks

The appearance of SARS-CoV-2 in 2019 triggered a significant economic and health crisis worldwide, with heterogeneous molecular mechanisms that contribute to its development are not yet fully understood. Although substantial progress has been made in elucidating the mechanisms behind SARS-CoV-2 infection and therapy, it continues to rank among the top three global causes of mortality due to infectious illnesses. Non-coding RNAs (ncRNAs), being integral components across nearly all biological processes, demonstrate effective importance in viral pathogenesis. Regarding viral infections, ncRNAs have demonstrated their ability to modulate host reactions, viral replication, and host-pathogen interactions. However, the complex interactions of different types of ncRNAs in the progression of COVID-19 remains understudied. In recent years, a novel mechanism of post-transcriptional gene regulation known as "competing endogenous RNA (ceRNA)" has been proposed. Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and viral ncRNAs function as ceRNAs, influencing the expression of associated genes by sequestering shared microRNAs. Recent research on SARS-CoV-2 has revealed that disruptions in specific ceRNA regulatory networks (ceRNETs) contribute to the abnormal expression of key infection-related genes and the establishment of distinctive infection characteristics. These findings present new opportunities to delve deeper into the underlying mechanisms of SARS-CoV-2 pathogenesis, offering potential biomarkers and therapeutic targets. This progress paves the way for a more comprehensive understanding of ceRNETs, shedding light on the intricate mechanisms involved. Further exploration of these mechanisms holds promise for enhancing our ability to prevent viral infections and develop effective antiviral treatments.

ABBV-744 alleviates LPS-induced neuroinflammation via regulation of BATF2-IRF4-STAT1/3/5 axis

Suppression of neuroinflammation using small molecule compounds targeting the key pathways in microglial inflammation has attracted great interest. Recently, increasing attention has been gained to the role of the second bromodomain (BD2) of the bromodomain and extra-terminal (BET) proteins, while its effect and molecular mechanism on microglial inflammation has not yet been explored. In this study, we evaluated the therapeutic effects of ABBV-744, a BD2 high selective BET inhibitor, on lipopolysaccharide (LPS)-induced microglial inflammation in vitro and in vivo, and explored the key pathways by which ABBV-744 regulated microglia-mediated neuroinflammation. We found that pretreatment of ABBV-744 concentration-dependently inhibited the expression of LPS-induced inflammatory mediators/enzymes including NO, TNF-α, IL-1β, IL-6, iNOS, and COX-2 in BV-2 microglial cells. These effects were validated in LPS-treated primary microglial cells. Furthermore, we observed that administration of ABBV-744 significantly alleviated LPS-induced activation of microglia and transcriptional levels of pro-inflammatory factors TNF-α and IL-1β in mouse hippocampus and cortex. RNA-Sequencing (RNA-seq) analysis revealed that ABBV-744 induced 508 differentially expressed genes (DEGs) in LPS-stimulated BV-2 cells, and gene enrichment and gene expression network analysis verified its regulation on activated microglial genes and inflammatory pathways. We demonstrated that pretreatment of ABBV-744 significantly reduced the expression levels of basic leucine zipper ATF-like transcription factor 2 (BATF2) and interferon regulatory factor 4 (IRF4), and suppressed JAK-STAT signaling pathway in LPS-stimulated BV-2 cells and mice, suggesting that the anti-neuroinflammatory effect of ABBV-744 might be associated with regulation of BATF2-IRF4-STAT1/3/5 pathway, which was confirmed by gene knockdown experiments. This study demonstrates the effect of a BD2 high selective BET inhibitor, ABBV-744, against microglial inflammation, and reveals a BATF2-IRF4-STAT1/3/5 pathway in regulation of microglial inflammation, which might provide new clues for discovery of effective therapeutic strategy against neuroinflammation.

The role of BATF2 deficiency in immune microenvironment rearrangement in cervical cancer - New biomarker benefiting from combination of radiotherapy and immunotherapy

Despite the significant progress in immunotherapy for certain cancers, including cervical cancer, most patients remain unresponsive or derive limited benefits from combined radiotherapy and chemotherapy. The factors underlying treatment resistance are unknown and there are few reliable predictive biomarkers. BATF2 is a member of the basic leucine zipper transcription factor family and is involved in immune response and immune cell development. However, the role of BATF2 in the immune microenvironment of patients with cervical cancer after radiotherapy remains unclear. In this study, immunohistochemistry and multicolour immunofluorescence analyses of patient tumor samples were used to assess BATF2 expression. We found that cervical cancer patients with high BATF2 expression had higher infiltration levels of CD4+ T cells, CD8+ T cells, and macrophages within the tumor than those with low expression levels. Furthermore, BATF2 expression was positively correlated with the prognosis of patients after concurrent chemoradiotherapy. A wild-type mouse model with BATF2-knockdown U14 cell-derived subcutaneous tumors and a Batf2-/- mouse model with wild-type U14 cell-derived subcutaneous tumors were used to assess CD8+ T cell infiltration and function. As expected, the knockdown of BATF2 in the U14 cell line substantially promoted tumor growth, which was mediated by a reduction in CD8+ T cell infiltration and antitumor function in vivo. Additionally, the Batf2-/- mouse model demonstrated that host BATF2 is also involved in controlling tumor growth. Furthermore, the combination of radiotherapy and anti-PD-1 therapy showed synergistic antitumour effects. These findings collectively suggest that BATF2 may serve as a potent positive regulator of the tumor immune microenvironment of cervical cancer after radiotherapy, and has the potential to be a prognostic biomarker to guide the application of a combination of radiotherapy and immunotherapy.

Differential dependence on microbiota of IL-23/IL-22-dependent gene expression between the small- and large-intestinal epithelia

In the intestine, interleukin (IL)-23 and IL-22 from immune cells in the lamina propria contribute to maintenance of the gut epithelial barrier through the induction of antimicrobial production and the promotion of epithelial cell proliferation. Several previous studies suggested that some of the functions of the IL-23/IL-22 axis on intestinal epithelial cells are shared between the small and large intestines. However, the similarities and differences of the IL-23/IL-22 axis on epithelial cells between these two anatomical sites remain unclear. Here, we comprehensively analyzed the gene expression of intestinal epithelial cells in the ileum and colon of germ-free, Il23-/- , and Il22-/- mice by RNA-sequencing. We found that while the IL-23/IL-22 axis is largely dependent on gut microbiota in the small intestine, it is much less dependent on it in the large intestine. In addition, the negative regulation of lipid metabolism in the epithelial cells by IL-23 and IL-22 in the small intestine was revealed, whereas the positive regulation of epithelial cell proliferation by IL-23 and IL-22 in the large intestine was highlighted. These findings shed light on the intestinal site-specific role of the IL-23/IL-22 axis in maintaining the physiological functions of intestinal epithelial cells.

BATF2 enhances proinflammatory cytokine responses in macrophages and improves early host defense against pulmonary Klebsiella pneumoniae infection

Basic leucine zipper transcription factor ATF-like 2 (BATF2) is a transcription factor that is emerging as an important regulator of the innate immune system. BATF2 is among the top upregulated genes in human alveolar macrophages treated with LPS, but the signaling pathways that induce BATF2 expression in response to Gram-negative stimuli are incompletely understood. In addition, the role of BATF2 in the host response to pulmonary infection with a Gram-negative pathogen like Klebsiella pneumoniae (Kp) is not known. We show that induction of Batf2 gene expression in macrophages in response to Kp in vitro requires TRIF and type I interferon (IFN) signaling, but not MyD88 signaling. Analysis of the impact of BATF2 deficiency on macrophage effector functions in vitro showed that BATF2 does not directly impact macrophage phagocytic uptake and intracellular killing of Kp. However, BATF2 markedly enhanced macrophage proinflammatory gene expression and Kp-induced cytokine responses. In vivo, Batf2 gene expression was elevated in lung tissue of wild-type (WT) mice 24 h after pulmonary Kp infection, and Kp-infected BATF2-deficient (Batf2-/-) mice displayed an increase in bacterial burden in the lung, spleen, and liver compared with WT mice. WT and Batf2-/- mice showed similar recruitment of leukocytes following infection, but in line with in vitro observations, proinflammatory cytokine levels in the alveolar space were reduced in Batf2-/- mice. Altogether, these results suggest that BATF2 enhances proinflammatory cytokine responses in macrophages in response to Kp and contributes to the early host defense against pulmonary Kp infection.NEW & NOTEWORTHY This study investigates the signaling pathways that mediate induction of BATF2 expression downstream of TLR4 and also the impact of BATF2 on the host defense against pulmonary Kp infection. We demonstrate that Kp-induced upregulation of BATF2 in macrophages requires TRIF and type I IFN signaling. We also show that BATF2 enhances Kp-induced macrophage cytokine responses and that BATF2 contributes to the early host defense against pulmonary Kp infection.

Sialylation shapes mucus architecture inhibiting bacterial invasion in the colon

In the intestine, mucin 2 (Muc2) forms a network structure and prevents bacterial invasion. Glycans are indispensable for Muc2 barrier function. Among various glycosylation patterns of Muc2, sialylation inhibits bacteria-dependent Muc2 degradation. However, the mechanisms by which Muc2 creates the network structure and sialylation prevents mucin degradation remain unknown. Here, by focusing on two glycosyltransferases, St6 N-acetylgalactosaminide α-2,6-sialyltransferase 6 (St6galnac6) and β-1,3-galactosyltransferase 5 (B3galt5), mediating the generation of desialylated glycans, we show that sialylation forms the network structure of Muc2 by providing negative charge and hydrophilicity. The colonic mucus of mice lacking St6galnac6 and B3galt5 was less sialylated, thinner, and more permeable to microbiota, resulting in high susceptibility to intestinal inflammation. Mice with a B3galt5 mutation associated with inflammatory bowel disease (IBD) also showed the loss of desialylated glycans of mucus and the high susceptibility to intestinal inflammation, suggesting that the reduced sialylation of Muc2 is associated with the pathogenesis of IBD. In mucins of mice with reduced sialylation, negative charge was reduced, the network structure was disturbed, and many bacteria invaded. Thus, sialylation mediates the negative charging of Muc2 and facilitates the formation of the mucin network structure, thereby inhibiting bacterial invasion in the colon to maintain gut homeostasis.

Loss of the Immunomodulatory Transcription Factor BATF2 in Humans Is Associated with a Neurological Phenotype

Epilepsy and mental retardation are known to be associated with pathogenic mutations in a broad range of genes that are expressed in the brain and have a role in neurodevelopment. Here, we report on a family with three affected individuals whose clinical symptoms closely resemble a neurodevelopmental disorder. Whole-exome sequencing identified a homozygous stop-gain mutation, p.Gln19*, in the BATF2 gene in the patients. The BATF2 transcription factor is predominantly expressed in macrophages and monocytes and has been reported to modulate AP-1 transcription factor-mediated pro-inflammatory responses. Transcriptome analysis showed altered base-level expression of interferon-stimulated genes in the patients' blood, typical for type I interferonopathies. Peripheral blood mononuclear cells from all three patients demonstrated elevated responses to innate immune stimuli, which could be reproduced in CRISPR-Cas9-generated BATF2^-/- human monocytic cell lines. BATF2 is, therefore, a novel disease-associated gene candidate for severe epilepsy and mental retardation related to dysregulation of immune responses, which underscores the relevance of neuroinflammation for epilepsy.

Identifying key genes in CD4+ T cells of systemic lupus erythematosus by integrated bioinformatics analysis

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by excessive activation of T and B lymphocytes and breakdown of immune tolerance to autoantigens. Despite several mechanisms including the genetic alterations and inflammatory responses have been reported, the overall signature genes in CD4⁺ T cells and how they affect the pathological process of SLE remain to be elucidated. This study aimed to identify the crucial genes, potential biological processes and pathways underlying SLE pathogenesis by integrated bioinformatics. The gene expression profiles of isolated peripheral CD4⁺ T cells from SLE patients with different disease activity and healthy controls (GSE97263) were analyzed, and 14 co-expression modules were identified using weighted gene co-expression network analysis (WGCNA). Some of these modules showed significantly positive or negative correlations with SLE disease activity, and primarily enriched in the regulation of type I interferon and immune responses. Next, combining time course sequencing (TCseq) with differentially expressed gene (DEG) analysis, crucial genes in lupus CD4⁺ T cells were revealed, including some interferon signature genes (ISGs). Among these genes, we identified 4 upregulated genes (PLSCR1, IFI35, BATF2 and CLDN5) and 2 downregulated genes (GDF7 and DERL3) as newfound key genes. The elevated genes showed close relationship with the SLE disease activity. In general, our study identified 6 novel biomarkers in CD4⁺ T cells that might contribute to the diagnosis and treatment of SLE.

STING inhibitor ameliorates LPS-induced ALI by preventing vascular endothelial cells-mediated immune cells chemotaxis and adhesion

Acute lung injury (ALI) is a common and devastating clinical disorder featured by excessive inflammatory responses. Stimulator of interferon genes (STING) is an indispensable molecule for regulating inflammation and immune response in multiple diseases, but the role of STING in the ALI pathogenesis is not well elucidated. In this study, we explored the molecular mechanisms of STING in regulating lipopolysaccharide (LPS)-induced lung injury. Mice were pretreated with a STING inhibitor C-176 (15, 30 mg/kg, i.p.) before LPS inhalation to induce ALI. We showed that LPS inhalation significantly increased STING expression in the lung tissues, whereas C-176 pretreatment dose-dependently suppressed the expression of STING, decreased the production of inflammatory cytokines including TNF-α, IL-6, IL-12, and IL-1β, and restrained the expression of chemokines and adhesion molecule vascular cell adhesion protein-1 (VCAM-1) in the lung tissues. Consistently, in vitro experiments conducted in TNF-α-stimulated HMEC-1cells (common and classic vascular endothelial cells) revealed that human STING inhibitor H-151 or STING siRNA downregulated the expression levels of adhesion molecule and chemokines in HMEC-1cells, accompanied by decreased adhesive ability and chemotaxis of immunocytes upon TNF-α stimulation. We further revealed that STING inhibitor H-151 or STING knockdown significantly decreased the phosphorylation of transcription factor STAT1, which subsequently influenced its binding to chemokine CCL2 and adhesive molecule VCAM-1 gene promoter. Collectively, STING inhibitor can alleviate LPS-induced ALI in mice by preventing vascular endothelial cells-mediated immune cell chemotaxis and adhesion, suggesting that STING may be a promising therapeutic target for the treatment of ALI.

The Blockade of Interleukin-2 During the Acute Phase of Trypanosoma cruzi Infection Reveals Its Dominant Regulatory Role

Trypanosoma cruzi infection causes Chagas’ disease in humans. The infection activates the innate and adaptative immunity in an orchestrated immune response to control parasite growth, guaranteeing host survival. Despite an effective immune response to the parasite in the acute phase, the infection progresses to a chronic stage. The parasite infects different tissues such as peripheral neurons, the brain, skeletal muscle, and heart muscle, among many others. It is evident now that tissue-specific immune responses may develop along with anti-parasite immunity. Therefore, mechanisms to regulate immunity and to ensure tissue-specific tolerance are operating during the infection. Studying those immunoregulatory mechanisms is fundamental to improve host protection or control inflammatory reactions that may lead to pathology. The role of IL-2 during T. cruzi infection is not established. IL-2 production by T cells is strongly down-modulated early in the disease by unknown mechanisms and remains low during the chronic phase of the disease. IL-2 activates NK cells, CD4, and CD8 T cells and may be necessary to immunity development. Also, the expansion and maintenance of regulatory T cells require IL-2. Thus, IL-2 may be a key cytokine involved in promoting or down-regulating immune responses, probably in a dose-dependent manner. This study blocked IL-2 during the acute T. cruzi infection by using a neutralizing monoclonal antibody. The results show that parasitemia and mortality rate was lower in animals treated with anti-IL-2. The percentages and total numbers of CD4⁺CD25⁺Foxp3⁺ T cells diminished within three weeks of infection. The numbers of splenic activated/memory CD4 and CD8 splenic T cells increased during the acute infection. T cells producing IFN-γ, TNF-α and IL-10 also augmented in anti-IL-2-treated infected mice. The IL-2 blockade also increased the numbers of inflammatory cells in the heart and skeletal muscles and the amount of IL-17 produced by heart T cells. These results suggest that IL-2 might be involved in the immune regulatory response during the acute T. cruzi infection, dampening T cell activation through the expansion/maintenance of regulatory T cells and regulating IL-17 production. Therefore, the IL-2 pathway is an attractive target for therapeutic purposes in acute and chronic phases of Chagas’ disease.

Uncovering potential single nucleotide polymorphisms, copy number variations and related signaling pathways in primary Sjogren's syndrome

Primary Sjogren’s syndrome (pSS) is a complex systemic autoimmune disease, which is difficult to accurately diagnose due to symptom diversity in patients, especially at earlier stages. We tried to find potential single nucleotide polymorphisms (SNPs), copy number variations (CNVs) and related signaling pathways. Genomic DNA was extracted from peripheral blood of 12 individuals (7 individuals from 3 pSS pedigrees and 5 sporadic cases) for whole-exome sequencing (WES) analysis. SNPs and CNVs were identified, followed by functional annotation of genes with SNPs and CNVs. Gene expression profile (involving 64 normal controls and 166 cases) was downloaded from the Gene Expression Omnibus database (GEO) dataset for differentially expression analysis. Sanger sequencing and in vitro validation was used to validate the identified SNPs and differentially expressed genes, respectively. A total of 5 SNPs were identified in both pedigrees and sporadic cases, such as FES, PPM1J, and TRAPPC9. A total of 3402 and 19 CNVs were identified in pedigrees and sporadic cases, respectively. Fifty-one differentially expressed genes were associated with immunity, such as BATF3, LAP3, BATF2, PARP9, and IL15RA. AMPK signaling pathway and cell adhesion molecules (CAMs) were the most significantly enriched signaling pathways of identified SNPs. Identified CNVs were associated with systemic lupus erythematosus, mineral absorption, and HTLV-I infection. IL2-STAT5 signaling, interferon-gamma response, and interferon-alpha response were significantly enriched immune related signaling pathways of identified differentially expressed genes. In conclusion, our study found some potential SNPs, CNVs, and related signaling pathways, which could be useful in understanding the pathological mechanism of pSS.

A Genome-Wide Association Study Identifies Novel Susceptibility loci in Chronic Chagas Cardiomyopathy

BACKGROUND

Chagas disease is an infectious disease caused by the parasite Trypanosoma cruzi and is endemic from Latin American countries. The goal of our study was to identify novel genetic loci associated with chronic Chagas cardiomyopathy development in Chagas disease patients from different Latin American populations.

METHODS

We performed a cross-sectional, nested case-control study including 3 sample collections from Colombia, Argentina, and Bolivia. Samples were genotyped to conduct a genome-wide association study (GWAS). These results were meta-analyzed with summary statistic data from Brazil, gathering a total of 3413 Chagas disease patients. To identify the functional impact of the associated variant and its proxies, we performed an in silico analysis of this region.

RESULTS

The meta-analysis revealed a novel genome-wide statistically significant association with chronic Chagas cardiomyopathy development in rs2458298 (OR = 0.90, 95%CI = 0.87-0.94, P-value = 3.27 × 10-08), nearby the SAC3D1 gene. In addition, further in silico analyses displayed functional relationships between the associated variant and the SNX15, BAFT2, and FERMT3 genes, related to cardiovascular traits.

CONCLUSIONS

Our findings support the role of the host genetic factors in the susceptibility to the development of the chronic cardiac form of this neglected disease.

Oxidative stress implications for therapeutic vaccine development against Chagas disease

INTRODUCTION

Pathogenesis of Chagas disease (CD) caused by the protozoan parasite Trypanosoma cruzi (T. cruzi) involves chronic oxidative and inflammatory stress. In this review, we discuss the research efforts in therapeutic vaccine development to date and the potential challenges imposed by oxidative stress in achieving an efficient therapeutic vaccine against CD.

AREAS COVERED

This review covers the immune and nonimmune mechanisms of reactive oxygen species production and immune response patterns during T. cruzi infection in CD. A discussion on immunotherapy development efforts, the efficacy of antigen-based immune therapies against T. cruzi, and the role of antioxidants as adjuvants is discussed to provide promising insights to developing future treatment strategies against CD.

EXPERT OPINION

Administration of therapeutic vaccines can be a good option to confront persistent parasitemia in CD by achieving a rapid, short-lived stimulation of type 1 cell-mediated immunity. At the same time, adjunct therapies could play a critical role in the preservation of mitochondrial metabolism and cardiac muscle contractility in CD. We propose combined therapy with antigen-based vaccine and small molecules to control the pathological oxidative insult would be effective in the conservation of cardiac structure and function in CD.

MTADV 5-MER peptide suppresses chronic inflammations as well as autoimmune pathologies and unveils a new potential target-Serum Amyloid A

Despite the existence of potent anti-inflammatory biological drugs e.g., anti-TNF and anti IL-6 receptor antibodies, for treating chronic inflammatory and autoimmune diseases, these are costly and not specific. Cheaper oral available drugs remain an unmet need. Expression of the acute phase protein Serum Amyloid A (SAA) is dependent on release of pro-inflammatory cytokines IL-1, IL-6 and TNF-α during inflammation. Conversely, SAA induces pro-inflammatory cytokine secretion, including Th17, leading to a pathogenic vicious cycle and chronic inflammation. 5- MER peptide (5-MP) MTADV (methionine-threonine-alanine-aspartic acid-valine), also called Amilo-5MER, was originally derived from a sequence of a pro-inflammatory CD44 variant isolated from synovial fluid of a Rheumatoid Arthritis (RA) patient. This human peptide displays an efficient anti-inflammatory effects to ameliorate pathology and clinical symptoms in mouse models of RA, Inflammatory Bowel Disease (IBD) and Multiple Sclerosis (MS). Bioinformatics and qRT-PCR revealed that 5-MP, administrated to encephalomyelytic mice, up-regulates genes contributing to chronic inflammation resistance. Mass spectrometry of proteins that were pulled down from an RA synovial cell extract with biotinylated 5-MP, showed that it binds SAA. 5-MP disrupted SAA assembly, which is correlated with its pro-inflammatory activity. The peptide MTADV (but not scrambled TMVAD) significantly inhibited the release of pro-inflammatory cytokines IL-6 and IL-1β from SAA-activated human fibroblasts, THP-1 monocytes and peripheral blood mononuclear cells. 5-MP suppresses the pro-inflammatory IL-6 release from SAA-activated cells, but not from non-activated cells. 5-MP could not display therapeutic activity in rats, which are SAA deficient, but does inhibit inflammations in animal models of IBD and MS, both are SAA-dependent, as shown by others in SAA knockout mice. In conclusion, 5-MP suppresses chronic inflammation in animal models of RA, IBD and MS, which are SAA-dependent, but not in animal models, which are SAA-independent.

Promotion Effect of EGCG on the Raised Expression of IL-23 through the Signaling of STAT3-BATF2-c-JUN/ATF2

Tea polyphenol of epigallocatechin-3-gallate (EGCG) has been verified to possess multiple biological activities. Interleukin-23 (IL-23) is a heterodimeric cytokine consisting of two subunits of IL-23p19 and IL-12p40, with the functionality in regulating the production of cytokines under physiological or pathological conditions. By serendipity, the raised expression of IL-23 was observed after treating cells with EGCG, whereas the detailed mechanism remains poorly understood. This study was proposed to investigate the signaling related to EGCG-induced IL-23. The raised expression of IL-23 was confirmed primarily by intraperitoneally injecting with different concentrations of EGCG (0, 20, 50, 80 mg/kg) into BALB/c mice, and the raised expression was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Results from enzyme-linked immunosorbent assay (ELISA) revealed the increase of IL-23 in serum from 116.09 to 153.90 pg/mL after treating with EGCG. The same results were also observed in RAW264.7 and peritoneal macrophages after treating with EGCG (0, 1, 5, 10, 25 μM) with the increased tendency of IL-23 in cultural medium (7.98 to 25.38 pg/mL for RAW264.7; 3.64 to 260.93 pg/mL for peritoneal macrophages). After preliminary exploration of the signaling related to the increased IL-23, the classical signaling pathways and key transcription factors, such as nuclear factor kappa-B (NF-κB), mitogen-activated protein kinase (MAPK) signaling pathways, and interferon regulatory factor 5 (IRF5), were demonstrated with no relevant contribution. A further study revealed the involvement of the key transcription factor of BATF2, which could antagonistically modulate the transcription and translation of IL-23. The signaling of STAT3-BATF2-c-JUN/ATF2-IL-23 has been further verified in RAW264.7 macrophages using the STAT3 inhibitor of AG490 and the activator of Colivelin TFA. The results indicated that EGCG inhibits the phosphorylation of STAT3 to facilitate the decreased level of BATF2, which contributed to the increased level of IL-23 by the enhancing heterodimerization of c-JUN and ATF2.

Comprehensive Transcriptomic Analysis Identifies Novel Antiviral Factors Against Influenza A Virus Infection

Influenza A virus (IAV) has a higher genetic variation, leading to the poor efficiency of traditional vaccine and antiviral strategies targeting viral proteins. Therefore, developing broad-spectrum antiviral treatments is particularly important. Host responses to IAV infection provide a promising approach to identify antiviral factors involved in virus infection as potential molecular drug targets. In this study, in order to better illustrate the molecular mechanism of host responses to IAV and develop broad-spectrum antiviral drugs, we systematically analyzed mRNA expression profiles of host genes in a variety of human cells, including transformed and primary epithelial cells infected with different subtypes of IAV by mining 35 microarray datasets from the GEO database. The transcriptomic results showed that IAV infection resulted in the difference in expression of amounts of host genes in all cell types, especially those genes participating in immune defense and antiviral response. In addition, following the criteria of P<0.05 and |logFC|≥1.5, we found that some difference expression genes were overlapped in different cell types under IAV infection via integrative gene network analysis. IFI6, IFIT2, ISG15, HERC5, RSAD2, GBP1, IFIT3, IFITM1, LAMP3, USP18, and CXCL10 might act as key antiviral factors in alveolar basal epithelial cells against IAV infection, while BATF2, CXCL10, IFI44L, IL6, and OAS2 played important roles in airway epithelial cells in response to different subtypes of IAV infection. Additionally, we also revealed that some overlaps (BATF2, IFI44L, IFI44, HERC5, CXCL10, OAS2, IFIT3, USP18, OAS1, IFIT2) were commonly upregulated in human primary epithelial cells infected with high or low pathogenicity IAV. Moreover, there were similar defense responses activated by IAV infection, including the interferon-regulated signaling pathway in different phagocyte types, although the differentially expressed genes in different phagocyte types showed a great difference. Taken together, our findings will help better understand the fundamental patterns of molecular responses induced by highly or lowly pathogenic IAV, and the overlapped genes upregulated by IAV in different cell types may act as early detection markers or broad-spectrum antiviral targets.

BATF2 balances the T cell-mediated immune response of CADM with an anti-MDA5 autoantibody

OBJECTIVES

Clinically amyopathic dermatomyositis (CADM) is a subtype of dermatomyositis (DM) characterized by low-grade or absent muscle inflammation but frequent and rapidly progressive interstitial lung disease (RP-ILD) and skin ulcers with anti-melanoma differentiation-associated gene 5 (anti-MDA5) autoantibodies. Basic leucine zipper transcription factor ATF-like 2 (BATF2) is thought to function as an inhibitor of tumours and inflammation. Here, we aimed to investigate the roles of BATF2 in Th cell differentiation of CADM with an anti-MDA5 autoantibody (anti-MDA5⁺ CADM).

METHODS

Naive CD4⁺ T cells from human peripheral blood mononuclear cells (PBMCs) of healthy controls (HCs) were isolated and then cultured with IL-12, TGF-β or TGF-β plus IL-6 following anti-CD3 and anti-CD28 stimulations. The expression of BATF2 was measured by real-time PCR. The percentages of Th1, Th17 and Treg CD4⁺ T cells were detected by flow cytometry. BATF2 knockdown of CD4⁺ T cells was performed using small interfering RNAs (siRNAs).

RESULTS

The expression of BATF2 in PBMCs was higher in anti-MDA5⁺ CADM patients than in healthy controls. The BATF2 mRNA expression was increased under Th1 and Treg polarization but decreased under Th17 polarization. Th17 cell activation-associated genes were possibly increased while Th1 and Treg cell differentiation-associated genes were inhibited by posttranscriptional gene silencing of BATF2 in CD4⁺ T cells.

CONCLUSIONS

BATF2 promoted Th1 and Treg cell differentiation but suppressed Th17 cell activation in anti-MDA5⁺ CADM.

Comparative Transcriptomic Analysis of Rhinovirus and Influenza Virus Infection

Rhinovirus (RV) and influenza virus are the most frequently detected respiratory viruses among adult patients with community acquired pneumonia. Previous clinical studies have identified major differences in the clinical presentations and inflammatory or immune response during these infections. A systematic transcriptomic analysis directly comparing influenza and RV is lacking. Here, we sought to compare the transcriptomic response to these viral infections. Human airway epithelial Calu-3 cells were infected with contemporary clinical isolates of RV, influenza A virus (IAV), or influenza B virus (IBV). Host gene expression was determined using RNA-seq. Differentially expressed genes (DEGs) with respect to mock-infected cells were identified using the overlapping gene-set of four different statistical models. Transcriptomic analysis showed that RV-infected cells have a more blunted host response with fewer DEGs than IAV or IBV-infected cells. IFNL1 and CXCL10 were among the most upregulated DEGs during RV, IAV, and IBV infection. Other DEGs that were highly expressed for all 3 viruses were mainly genes related to type I or type III interferons (RSAD2, IDO1) and chemokines (CXCL11). Notably, ICAM5, a known receptor for enterovirus D68, was highly expressed during RV infection only. Gene Set Enrichment Analysis (GSEA) confirmed that pathways associated with interferon response, innate immunity, or regulation of inflammatory response, were most perturbed for all three viruses. Network analysis showed that steroid-related pathways were enriched. Taken together, our data using contemporary virus strains suggests that genes related to interferon and chemokine predominated the host response associated with RV, IAV, and IBV infection. Several highly expressed genes, especially ICAM5 which is preferentially-induced during RV infection, deserve further investigation.

Thioridazine aggravates skeletal myositis, systemic and liver inflammation in Trypanosoma cruzi-infected and benznidazole-treated mice

While thioridazine (Tio) inhibits the antioxidant defenses of Trypanosoma cruzi, the gold standard antitrypanosomal drug benznidazole (Bz) has potent anti-inflammatory and pro-oxidant properties. The combination of these drugs has never been tested to determine the effect on T. cruzi infection. Thus, we compared the impact of Tio and Bz, administered alone and in combination, on the development of skeletal myositis and liver inflammation in T. cruzi-infected mice. Swiss mice were randomized into six groups: uninfected untreated, infected untreated, treated with Tio (80 mg/kg) alone, Bz (50 or 100 mg/kg) alone, or a combination of Tio and Bz. Infected animals were inoculated with a virulent T. cruzi strain (Y) and treated by gavage for 20 days. Mice untreated or treated with Tio alone developed the most intense parasitemia, highest parasitic load, elevated IL-10, IL-17, IFN-γ, and TNF-α plasma levels, increased N-acetylglucosaminidase and myeloperoxidase activity in the liver and skeletal muscle, as well as severe myositis and liver inflammation (P < 0.05). All parameters were markedly attenuated in animals receiving Bz alone (P < 0.05). However, the co-administration of Tio impaired the response to Bz chemotherapy, causing a decrease in parasitological control (parasitemia and parasite load), skeletal muscle and liver inflammation, and increased microstructural damage, when compared to the group receiving Bz alone (P < 0.05). Altogether, our findings indicated that Tio aggravates systemic inflammation, skeletal myositis and hepatic inflammatory damage in T. cruzi-infected mice. By antagonizing the antiparasitic potential of Bz, Tio limits the anti-inflammatory, myoprotectant and hepatoprotective effects of the reference chemotherapy, aggravating the pathological remodeling of both organs. As the interaction of T. cruzi infection, Bz and Tio is potentially toxic to the liver, inducing inflammation and microvesicular steatosis; this drug combination represents a worrying pharmacological risk factor in Chagas disease.

Interleukin-17 mediated immunity during infections with Trypanosoma cruzi and other protozoans

Host resistance during infection with Trypanosoma cruzi, and other protozoans, is dependent on a balanced immune response. Robust immunity against these pathogens requires of the concerted action of many innate and adaptive cell populations including macrophages, neutrophils, dendritic cells, CD4+, and CD8+ T cells and B cells among others. Indeed, during most protozoan infections only a balanced production of inflammatory (TH1) and anti-inflammatory (TH2/regulatory) cytokines will allow the control of parasite spreading without compromising host tissue integrity. The description of TH17 cells, a novel effector helper T cell lineage that produced IL-17 as signature cytokine, prompted the revision of our knowledge about the mechanisms that mediate protection and immunopathology during protozoan infections. In this manuscript we discuss the general features of IL-17 mediated immune responses as well as the cellular sources, effector mechanisms and overall role of IL-17 in the immune response to T. cruzi and other protozoan infections.

Heme protects intestinal mucosal barrier in DSS-induced colitis through regulating macrophage polarization in both HO-1-dependent and HO-1-independent way

Hemoglobin-derived heme was reported to play protective roles in hemorrhagic diseases by modulating the macrophages toward recovery. Mucosal bleeding is one of the pathological features of inflammatory bowel diseases (IBD). However, whether heme provides anti-inflammatory profiles in macrophages, thus contributing to the intestinal mucosal barrier protection, is unclear. In the current study, we investigated the beneficial effects of heme on DSS-induced colitis mice and explored the underlying mechanisms. In vivo, systemic heme supplementation by hemin injection relieved intestinal inflammation and remedied intestinal mucosal barrier damage by correcting abnormal intestinal macrophage polarization. In vitro, we confirmed the reciprocally regulating effects of hemin on M1/M2 macrophage polarization in BMDM. Intriguingly, with knockdown of HO-1, the inhibiting effects of hemin on M1 polarization were maintained, while the promoting effects on M2 polarization were reversed. Further research proved that hemin repressed the inflammatory profiles in macrophages through inhibiting the translocation of NF-κB p65 by disrupting IRF5-NF-κB p65 complex formation in Spi-C-dependent way. In conclusion, these results showed that the modification of colon tissue microenvironment with heme supplementation plays a protective role in DSS-induced colitis mice through regulating the macrophage polarization in both HO-1-dependent and HO-1-independent way, indicating a new choice to therapeutically modulate the macrophage function and prevent IBD.

BATF2 prevents T-cell-mediated intestinal inflammation through regulation of the IL-23/IL-17 pathway

Inappropriate activation of the IL-23 signaling pathway causes chronic inflammation through the induction of immunopathological Th17 cells in several tissues including the intestine, whereas adequate Th17 responses are essential for host defense against harmful organisms. In the intestinal lamina propria, IL-23 is primarily produced by innate myeloid cells including dendritic cells (DCs) and macrophages (Mϕs). However, the molecular mechanisms underlying the regulation of IL-23 production by these cells remains poorly understood. In this study, we demonstrated that BATF2 regulates intestinal homeostasis by inhibiting IL-23-driven T-cell responses. Batf2 was highly expressed in intestinal innate myeloid subsets, such as monocytes, CD11b+ CD64+ Mϕs and CD103+ DCs. Batf2-/- mice spontaneously developed colitis and ileitis with altered microbiota composition. In this context, IL-23, but not TNF-α and IL-10, was produced in high quantities by intestinal CD11b+ CD64+ Mϕs from Batf2-/- mice compared with wild-type mice. Moreover, increased numbers of IFN-γ+, IL-17+ and IFN-γ+ IL-17+ CD4+ T cells, but not IL-10+ CD4+ T cells, accumulated in the colons and small intestines of Batf2-/- mice. In addition, RORγt-expressing innate lymphoid cells were increased in Batf2-/- mice. Batf2-/-Rag2-/- mice showed a reduction in intestinal inflammation present in Batf2-/- mice. Furthermore, the high numbers of intestinal IL-17+ and IFN-γ+ IL-17+ CD4+ T cells were markedly reduced in Batf2-/- mice when introducing Il23a deficiency, which was associated with the abrogation of intestinal inflammation. These results indicated that BATF2 in innate myeloid cells is a key molecule for the suppression of IL-23/IL-17 pathway-mediated adaptive intestinal pathology.

SARI prevents ocular angiogenesis and inflammation in mice

SARI (Suppressor of AP‐1, regulated by IFN‐β) is known to play an important role in some systemic disease processes such an inflammatory conditions and cancer. We hypothesize that SARI may also play a role in ocular diseases involving inflammation and neovascularization. To explore our hypothesis, further, we investigated an endotoxin‐induced uveitis (EIU) and experimental argon laser‐induced choroidal neovascularization (CNV) model in SARI wild‐type (SARI^WT) and SARI‐deficient (SARI^−/−) mice. Through imaging, morphological and immunohistochemical (IHC) studies, we found that SARI deficiency exacerbated the growth of CNV. More VEGF‐positive cells were presented in the retina of SARI^−/− mice with CNV. Compared to SARI^WT mice, more inflammatory cells infiltrated the ocular anterior segment and posterior segments in SARI^−/− mice with EIU. Collectively, the results point to a potential dual functional role of SARI in inflammatory ocular diseases, suggesting that SARI could be a potential therapy target for ocular inflammation and neovascularization.

IL-17A, a possible biomarker for the evaluation of treatment response in Trypanosoma cruzi infected children: A 12-months follow-up study in Bolivia

Background

The National Program for Chagas disease was implemented in Bolivia in 2006, and it greatly decreased the number of infections through vector control. Subsequently, a treatment regimen of benznidazole (BNZ) was started in seropositive school-age children living in certified vector control areas.

Methods and findings

We conducted a 12-month follow-up study and seven blood samples were taken during and after the treatment. Serology, conventional diagnostic PCR (cPCR) and quantitative Real-time PCR (qPCR) were performed. Plasma Th1/Th2/Th17 cytokines levels were also determined. Approximately 73 of 103 seropositive children complied with BNZ, with three interruptions due to side effects.

To evaluate each individual’s treatment efficacy, the cPCR and qPCR values during the final 6 months of the follow-up period were observed. Among 57 children who completed follow-up, 6 individuals (11%) showed both cPCR(+) and qPCR(+) (non reactive), 24 (42%) cPCR(-) but qPCR(+) (ambiguous) and 27 (47%) cPCR(-) and qPCR(-) (reactive).

Within 14 Th1/Th2/Th17 cytokines, IL-17A showed significantly higher levels in seropositive children before the treatment compared to age-matched seronegative children and significantly decreased to the normal level one-year after. Moreover, throughout the follow-up study, IL-17A levels were positively co-related to parasite counts detected by qPCR. At the 12 months’ time point, IL-17A levels of non-reactive subjects were significantly higher than either those of reactive or ambiguous subjects suggesting that IL-17A might be useful to determine the reactivity to BNZ treatment.

Conclusions

Plasma levels of IL-17A might be a bio-marker for detecting persistent infection of T. cruzi and its chronic inflammation.

Chagas is a zoonosis endemic in 21 Latin American countries caused by T. cruzi. Results of common Benznidazole (BNZ) treatment vary by infection phase, treatment period, and dosage. In Bolivia, the national Chagas program controls vector distribution in different regions of the country. The program began BNZ treatment in school-age children from infestation-free endemic areas. Lack of information regarding follow-up and efficacy in children with recent chronic Chagas makes treatment failure difficult to detect in endemic areas. The present study aimed to estimate parasite DNA in blood through quantitative real-time and conventional PCR (qPCR, cPCR), and observe Th1/Th2/Th17 cytokine profiling during a 12-month follow-up in Bolivia school children. Results showed persistence of low, substantial amounts of T. cruzi DNA, and significantly higher IL-17A levels in the seropositive group before treatment than the seronegative group, which decreased to seronegative levels one year later. Of 57 treated, 6 showed cPCR positive results 6 months after treatment and were diagnosed as definitely non-reactive (10.5%). The six non-reactive individuals showed significantly higher levels of IL-17A at 12 months than residual reactive (cPCR negative, qPCR negative) and ambiguously reactive (cPCR negative, qPCR positive) groups, indicating that IL-17A might be a biomarker for non-reactive to BNZ.

SARI attenuates colon inflammation by promoting STAT1 degradation in intestinal epithelial cells

SARI functions as a suppressor of colon cancer and predicts survival of colon cancer patients, but its role in regulating colitis has not been characterized. Here we show that SARI^-/- mice were highly susceptible to colitis, which was associated with enhanced macrophage infiltration and inflammatory cytokine production. Bone marrow reconstitution experiments demonstrated that disease susceptibility was not dependent on the deficiency of SARI in the immune compartment but on the protective role of SARI in the intestinal epithelial cells (IECs). Furthermore, SARI deficiency enhanced Chemokine (C-C motif) Ligand 2 (CCL2) production and knockout of CCR2 blocks the promoting role of SARI deficiency on colitis. Mechanistically, SARI directly targets and promotes signal transducer and activator of transcription 1 (STAT1) degradation in IECs, followed by persistent inactivation of the STAT1/CCL2 transcription complex. In summary, SARI attenuated colitis in mice by impairing colitis-dependent STAT1/CCL2 transcriptional activation in IECs and macrophages recruitment in colon tissue.

Batf2 differentially regulates tissue immunopathology in Type 1 and Type 2 diseases

Basic leucine zipper transcription factor 2 (Batf2) activation is detrimental in Type 1-controlled infectious diseases, demonstrated during infection with Mycobacterium tuberculosis (Mtb) and Listeria monocytogenes Lm. In Batf2-deficient mice (Batf2^-/-), infected with Mtb or Lm, mice survived and displayed reduced tissue pathology compared to infected control mice. Indeed, pulmonary inflammatory macrophage recruitment, pro-inflammatory cytokines and immune effectors were also decreased during tuberculosis. This explains that batf2 mRNA predictive early biomarker found in active TB patients is increased in peripheral blood. Similarly, Lm infection in human macrophages and mouse spleen and liver also increased Batf2 expression. In striking contrast, Type 2-controlled schistosomiasis exacerbates during infected Batf2^-/- mice with increased intestinal fibro-granulomatous inflammation, pro-fibrotic immune cells, and elevated cytokine production leading to wasting disease and early death. Together, these data strongly indicate that Batf2 differentially regulates Type 1 and Type 2 immunity in infectious diseases.

Heme ameliorates dextran sodium sulfate-induced colitis through providing intestinal macrophages with noninflammatory profiles

Following hemorrhage in damaged tissues, hemoglobin induces macrophages (Mϕs) possessing ability to protect against tissue inflammation. Hemorrhage-appearing mucosa is observed in patients with inflammatory bowel disease. However, heme-mediated modulation of intestinal Mϕ activity remains poorly understood. Here, we provide evidence that Spi-C induced by heme is a key molecule for providing noninflammatory gene expression patterns of intestinal CX₃CR1^high Mϕs. We found that the Spic deficiency in intestinal Mϕs resulted in increased sensitivity to dextran sodium sulfate-induced colitis. Heme-mediated Spi-C inhibited a subset of LPS-induced genes such as Il6 and Il1a by intestinal CX₃CR1^high Mϕs through inhibition of IRF5-NF-κB p65 complex formation. These results reveal a mechanism modulating the noninflammatory phenotype of intestinal Mϕs and may help identify targets for therapy of intestinal inflammation.

The local environment is crucial for shaping the identities of tissue-resident macrophages (Mϕs). When hemorrhage occurs in damaged tissues, hemoglobin induces differentiation of anti-inflammatory Mϕs with reparative function. Mucosal bleeding is one of the pathological features of inflammatory bowel diseases. However, the heme-mediated mechanism modulating activation of intestinal innate immune cells remains poorly understood. Here, we show that heme regulates gut homeostasis through induction of Spi-C in intestinal CX₃CR1^high Mϕs. Intestinal CX₃CR1^high Mϕs highly expressed Spi-C in a heme-dependent manner, and myeloid lineage-specific Spic-deficient (Lyz2-cre; Spic^flox/flox) mice showed severe intestinal inflammation with an increased number of Th17 cells during dextran sodium sulfate-induced colitis. Spi-C down-regulated the expression of a subset of Toll-like receptor (TLR)-inducible genes in intestinal CX₃CR1^high Mϕs to prevent colitis. LPS-induced production of IL-6 and IL-1α, but not IL-10 and TNF-α, by large intestinal Mϕs from Lyz2-cre; Spic^flox/flox mice was markedly enhanced. The interaction of Spi-C with IRF5 was linked to disruption of the IRF5-NF-κB p65 complex formation, thereby abrogating recruitment of IRF5 and NF-κB p65 to the Il6 and Il1a promoters. Collectively, these results demonstrate that heme-mediated Spi-C is a key molecule for the noninflammatory signature of intestinal Mϕs by suppressing the induction of a subset of TLR-inducible genes through binding to IRF5.

Regulatory Lymphoid and Myeloid Cells Determine the Cardiac Immunopathogenesis of Trypanosoma cruzi Infection

Chagas disease is a multisystemic disorder caused by the protozoan parasite Trypanosoma cruzi, which affects ~8 million people in Latin America, killing 7,000 people annually. Chagas disease is one of the main causes of death in the endemic area and the leading cause of infectious myocarditis in the world. T. cruzi infection induces two phases, acute and chronic, where the infection is initially asymptomatic and the majority of patients will remain clinically indeterminate for life. However, over a period of 10–30 years, ~30% of infected individuals will develop irreversible, potentially fatal cardiac syndromes (chronic chagasic cardiomyopathy [CCC]), and/or dilatation of the gastro-intestinal tract (megacolon or megaesophagus). Myocarditis is the most serious and frequent manifestation of chronic Chagas heart disease and appears in about 30% of infected individuals several years after infection occurs. Myocarditis is characterized by a mononuclear cell infiltrate that includes different types of myeloid and lymphoid cells and it can occur also in the acute phase. T. cruzi infects and replicates in macrophages and cardiomyocytes as well as in other nucleated cells. The pathogenesis of the chronic phase is thought to be dependent on an immune-inflammatory reaction to a low-grade replicative infection. It is known that cytokines produced by type 1 helper CD4+ T cells are able to control infection. However, the role that infiltrating lymphoid and myeloid cells may play in experimental and natural Chagas disease pathogenesis has not been completely elucidated, and several reports indicate that it depends on the mouse genetic background and parasite strain and/or inoculum. Here, we review the role that T cell CD4+ subsets, myeloid subclasses including myeloid-derived suppressor cells may play in the immunopathogenesis of Chagas disease with special focus on myocarditis, by comparing results obtained with different experimental animal models.

Decrease in invasion of HTR-8/SVneo trophoblastic cells by interferon gamma involves cross-communication of STAT1 and BATF2 that regulates the expression of JUN

Trophoblast invasion is one of the critical steps during embryo implantation. IFNG secreted during pregnancy by uterine NK cells acts as a negative regulator of invasion. IFNG in a dose dependent fashion inhibits invasion of HTR-8/SVneo trophoblastic cells. It phosphorylates STAT1 both at tyr 701 and ser 727 residues. Silencing of STAT1 significantly increases invasion (∼59%) of the cells. Based on NGS data, out of 207 genes, BATF2 expression was significantly increased after IFNG treatment. Silencing of BATF2 significantly increases the invasion of cells with (∼53%) or without (∼44%) treatment with IFNG. Expression of BATF2 and STAT1 is dependent on each other, silencing of one significantly inhibit the expression of other. Interestingly, phosphorylated JUN is also regulated by BATF2 and STAT1. Collectively, these findings showed that decrease in the invasion of HTR-8/SVneo cells after IFNG treatment is controlled by STAT1 and BATF2, which further regulates the expression of JUN.

Th-17 cytokines are associated with severity of Trypanosoma cruzi chronic infection in pediatric patients from endemic areas of Mexico

In Chagas disease the clinical, acute and chronic manifestations are the result of the interaction between the parasite and the host factors. The balance between inflammatory and anti-inflammatory immune responses is essential for the increase or resolution of the manifestations in individuals infected with T. cruzi. To identify if children with chronic Chagas disease and heart injury is related with non-regulated Th1, Th2 and Th17 responses. We included 31 children with T. cruzi confirmed chronic infection from endemic areas of Mexico. Subsequently, they were separated according to their ECHO and ECG results into three groups according to the severity of cardiac involvement. Circulating Th1, Th2 and Th17 cytokine profiles were performed by Luminex assays and the results were analyzed by bivariate and multivariable analysis. Patients were classified in asymptomatic chronic (group 1, N=12); individuals with IRBBB in ECG and incipient lesions in ECHO (Group 2, N=8) and Patients with severe chronic symptomatic disease (Group 3, N=11). The analysis of immune mediators revealed that patients with severe cardiac manifestations had significant higher levels (p <0.05) of Th17 related cytokines including IL-17 and IL-6 as well as IFN-γ and IL-2. Also patients with severe cardiomyopathy exhibit increased levels of IL-13 (p <0.05) after multivariate analysis. High levels of Th17 related cytokines including IL-17, IFN-γ, IL-6 and IL-2 and pro-fibrotic factors such as IL-13 could be associated to the severity of cardiac involvement in children with chronic T. cruzi infection. These cytokines could be useful as indicators for the early identification of cardiac damage associated to the T. cruzi infection.

Quantification of Trypanosoma cruzi in Tissue and Trypanosoma cruzi Killing Assay

Infection with Trypanosoma cruzi causes Chagas disease. The methods provided here allow for the quantification of T. cruzi in the liver, heart, and blood of intraperitoneally-infected mice and analysis of the killing activity of the cells infected with T. cruzi in vitro.

Pathophysiology of Leishmania Infection during Pregnancy

The pathological processes resulting from parasitic infection are known to have important impacts on the mother child dyad during pregnancy. The roles of parasite transmission and the maternal immune response have been described in diseases such as malaria, toxoplasmosis, and trypanosomiasis. However, the impact of parasites of the genus Leishmania, etiological agents of the neglected tropical diseases tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL), is comparatively less well known, though it is an increasingly recognized concern for infected mothers and their fetuses. In this review, we first consider the pathophysiology of placental infection and transplacental transmission of this parasite, and then discuss the role and mechanisms of the maternal immune system in simultaneously mediating maternal-fetal infection and adverse pregnancy outcomes.