IL-4 attenuates Th1-associated chemokine expression and Th1 trafficking to inflamed tissues and limits pathogen clearance

Macrophage expression of constitutively active TβRI alleviates hepatic injury in a mouse model of concanavalin A-induced autoimmune hepatitis

Transforming growth factor-β (Tgf-β) contributes to the development of liver diseases through its regulation of various cell types. While Tgf-β signaling to hepatic stellate cells (HSCs) and hepatocytes was shown to mediate hepatic damage, the effect of Tgf-β on other cells in liver is yet to be clearly defined. Herein we identified a regulatory function of macrophage Tgf-β signaling in liver injury. We found that transgenic mice expressing constitutively active Tgf-β receptor type I (TβRI CA ) under the control of Fsp1-Cre (TβRI CA /Fsp1-Cre mice) were less susceptible to concanavalin A (conA)-induced autoimmune hepatitis. Liver tissue examination showed a decrease of necrotic area in conA-treated TβRI CA /Fsp1-Cre liver compared to those of wild-type mice. Blood test revealed that serum aminotransferases were significantly reduced in conA-treated TβRI CA /Fsp1-Cre mice as compared to those of wild-type mice. Immunohistochemistry for CD3 and myeloperoxidase demonstrated that there was a decreased accumulation of T cells and neutrophils, respectively, whereas ELISA showed that IL-4, IL-5, IL-10, IL-12 and IFN-γ was increased in livers of conA-treated TβRI CA /Fsp1-Cre mice. Alternatively activated macrophage (M2) polarization was significantly elevated in livers of conA-treated TβRI CA /Fsp1-Cre mice as indicated by enhanced hepatic expression of CCR2 and CD206 as well as increased numbers of liver macrophages expressing M2 subtype marker, CD163. qPCR analysis indicated an increased expression of TβRI CA , Arg1, Ym1, CD206, Snail1, Foxo1 and IRF4 as well as a decreased expression of MHC class II and CD1d in liver macrophages that were isolated from TβRI CA /Fsp1-Cre mice. Moreover, flow cytometry analysis showed a lower number of NKT cells in livers of conA-treated TβRI CA /Fsp1-Cre mice when compared to those of wild-type mice. In conclusion, Fsp1-Cre-mediated expression of TβRI CA lead to a decreased conA-induced liver injury that was associated with enhanced M2 macrophage polarization and reduced NKT cell recruitment.

Research progress of T cells in cholangiocarcinoma

Cholangiocarcinoma (CCA), a malignant tumor, is typically challenging to detect early and often results in a poor prognosis. In recent years, research interest has grown in the potential application of immunotherapy for CCA treatment. T cells, as a crucial component of the immune system, play a significant role in immune surveillance and therapy for cholangiocarcinoma. This article provides a review of the research advancements concerning T cells in cholangiocarcinoma patients, including their distribution, functional status, and correlation with patient prognosis within the tumor microenvironment. It further discusses the potential applications and challenges of immunotherapy strategies targeting T cells in CCA treatment and anticipates future research directions. A more profound understanding of T cells' role in cholangiocarcinoma can guide the development of clinical treatment strategies, thereby enhancing patient survival rates and quality of life. Finally, we explored the potential risks and side effects of immunotherapy for T-cell cholangiocarcinoma.

Exploring Asthma as a Protective Factor in COVID-19 Outcomes

Asthma has long been associated with increased susceptibility to viral respiratory infections, leading to significant exacerbations and poorer clinical outcomes. Contrarily and interestingly, emerging data and research surrounding the COVID-19 pandemic have shown that patients with asthma infected with SARS-CoV-2 experienced decreased severity of disease, lower hospitalization rates, as well as decreased morbidity and mortality. Research has shown that eosinophils could enhance immune defense against viral infections, while inhaled corticosteroids can assist in controlling systematic inflammation. Moreover, reduced ACE-2 expression in individuals with asthma may restrict viral entry, and the Th2 immune response may offset the Th1 response typically observed in severe COVID-19 patients. These factors may help explain the favorable outcomes seen in asthmatic patients during the COVID-19 pandemic. This review highlights potential protective mechanisms seen in asthmatic patients, including eosinophilia, the use of inhaled corticosteroids, reduced ACE-2 expression, and a dominate Th2 immune response. Such a study will be helpful to better manage patients with asthma who have contracted COVID-19.

Solid Lipid Nanoparticles Encapsulated With Paromomycin: An Effective Oral Formulation Against Leishmania major in Mouse Model

Leishmaniasis is a disease caused by protozoan parasites of the genus Leishmania. The treatment of intracellular infections such as leishmaniasis is often challenging due to limited drug access to infected cells and the development of drug resistance. Therefore, the development of new antileishmanial compounds is essential. Paromomycin sulphate (PM) has shown promise as an antileishmanial drug, and one way to enhance its effectiveness is through appropriate delivery systems. Solid lipid nanoparticles (SLN) are being explored as a potential delivery system for PM, as they offer advantages over other colloidal carriers. In a recent study, PM was loaded into solid lipid nanoparticles (PM-SLN) and its oral effectiveness was evaluated in treating Leishmania (L.) major-infected mice. The study measured footpad swelling, quantified parasite load through real-time PCR and assessed levels of cytokines such as interleukin-4 (IL-4) and gamma interferon (IFN-c), nitric oxide (NO) and Arginase (ARG). Overall, the study demonstrated that oral administration of the PM-SLN formulation is safe and effective in treating leishmaniasis. The SLN in the PM-SLN compound improved the killing of parasites by PM and stimulated a Th1 immune response, indicating its potential as a treatment for leishmaniasis.

Anti-inflammatory effect of grounding mat on trimethyltin-induced neurotoxicity rats

Grounding, the practice of direct contact with the Earth's surface, has been explored for its potential to alleviate inflammation and neurotoxicity. Trimethyltin (TMT) is a potent neurotoxic compound known for inducing severe central nervous system damage, particularly neuronal death and neuroinflammation in the hippocampus, which is frequently used as an animal model to study neurodegenerative disorders, such as Alzheimer disease, due to its ability to induce oxidative stress, inflammatory responses, and neurodegeneration. This study investigated the effect of a grounding mat on cognitive function, neuroinflammation, and neuroprotection in a TMT-induced neurotoxicity rats. Rats were divided into five groups: no grounding mat with saline (Nor), no grounding mat with TMT (Con), electric mat for 21 days with TMT (EM), grounding mat for 7 days with TMT (A-7D), and grounding mat for 21 days with TMT (A-21D). Cognitive function was assessed via the Y-maze test, while blood levels of interleukin (IL)-1β, IL-4, prostaglandin E2 (PGE2), and hippocampal acetylcholinesterase (AChE) were measured by enzyme-linked immunosorbent assay. The Con group showed impaired memory and elevated IL-1β and PGE2 levels, alongside reduced IL-4, compared to the Nor group. The A-7D group improved memory performance, and the A-21D group showed reductions in IL-1β and P PGE2, with increased IL-4 levels. Both A-7D and A-21D groups had elevated AChE levels compared to the Con group. These findings suggest that grounding may enhance cognitive function by reducing inflammation and promoting neuroprotection in a neurotoxicity model.

Association between allergic diseases and mucosal healing in ulcerative colitis

Allergic diseases and ulcerative colitis (UC) share pathophysiological similarities. This study aimed to investigate the unclear association between allergic diseases and mucosal healing (MH), an important factor in the prognosis of UC. We studied 289 Japanese patients with UC. Information on allergic diseases (bronchial asthma, atopic dermatitis, pollen allergy, food allergy, and drug allergy), as diagnosed by physicians, was collected through self-reported questionnaires. The definition of MH was Mayo Endoscopic Score 0. The association between each allergic disease and its multimorbidity with MH was evaluated using multivariate logistic regression analyses. Pollen allergy was the most common allergic condition (36.3%). Pollen allergy and food allergy were independently associated with MH (pollen allergy adjusted OR: 1.82 [95% CI: 1.01-3.26]; food allergy adjusted OR: 3.47 [95% CI: 1.26-9.68]). The rates of MH for 0 and 3 or more allergic diseases were 24.6% and 4.2%, respectively. After adjustment for confounders, 3 or more allergic diseases were independently associated with MH (adjusted OR: 8.13 [95% CI: 2.17-34.04], p for trend = 0.020). This study demonstrates a significant positive association between specific allergic diseases (pollen and food allergies) and MH in UC patients, with a stronger association in cases of allergic multimorbidity.

The dichotomic role of cytokines in aging

The chronic inflammation present in aged individuals is generally depicted as a detrimental player for longevity. Here, it is discussed several beneficial effects associated with the cytokines that are chronically elevated in inflammaging. These cytokines, such as IL-1β, type I interferons, IL-6 and TNF positively regulate macroautophagy, mitochondrial function, anti-tumor immune responses and skeletal muscle biogenesis, possibly contributing to longevity. On the other side, the detrimental and antagonistic role of these cytokines including the induction of sarcopenia, tissue damage and promotion of tumorigenesis are also discussed, underscoring the dichotomy associated with inflammaging and its players. In addition, it is discussed the role of the anti-inflammatory cytokine IL-10 and other cytokines that affect aging in a more linear way, such as IL-11, which promotes senescence, and IL-4 and IL-15, which promotes longevity. It is also discussed more specific regulators of aging that are downstream cytokines-mediated signaling.

Chemokines Signature and T Cell Dynamics in Leishmaniasis: Molecular insight and therapeutic application

Leishmaniasis, caused by obligate intracellular Leishmania parasites, poses a significant global health burden. The control of Leishmania infection relies on an effective T cell-dependent immune response; however, various factors impede the host’s ability to mount a successful defence. Alterations in the chemokine profile, responsible for cell trafficking to the infection site, can disrupt optimal immune responses and influence the outcome of pathogenesis by facilitating parasite persistence. This review aims to emphasize the significance of the chemokine system in T cell responses and to summarize the current knowledge on the dysregulation of chemokines and their receptors associated with different subsets of T lymphocytes during Leishmaniasis. A comprehensive understanding of the dynamic nature of the chemokine system during Leishmaniasis is crucial for the development of successful immunotherapeutic approaches.

Rheumatic adverse events associated with biologic therapy for chronic rhinosinusitis: A systematic review and meta-analysis

BACKGROUND

Biologic therapies approved for treating chronic rhinosinusitis with nasal polyps (CRSwNP) have well-established safety profiles but reports of rheumatic adverse events (AEs) are increasing and not well defined. This review aims to assess the risk and incidence of rheumatic AEs associated with biologic therapy in CRSwNP and summarize current reported management strategies.

METHODS

A protocol was registered in PROSPERO [CRD42024525663]. A search was conducted in four electronic databases: Medline (Ovid), Embase, Scopus, and Cochrane CENTRAL from inception until January 4, 2024. Two reviewers independently screened citations and extracted data. Methodological quality was assessed using the Joanna Briggs Institute's critical appraisal tool. Data were pooled using a random effects model to calculate overall incidence and relative risk.

RESULTS

Twenty-one studies met the final inclusion criteria, totaling 3434 patients of which 2763 (80%) received either dupilumab (n = 2257; 82%), mepolizumab (n = 372; 13%), or omalizumab (n = 134; 5%) for treatment of CRSwNP. The overall incidence rate for any on-treatment rheumatic AE was 0.05 per person-year (95% CI, 0.03-0.09, I2 = 75%). Biologic therapy increased the risk of developing a rheumatic AE (RR = 2.53; 95% CI, 1.29-4.94) compared with placebo. The most frequently reported rheumatic AE was arthralgia or joint pain (n = 94; 95%), followed by lupus-like syndrome or lupus erythematosus-like reaction (n = 2; 2.5%). Discontinuation of treatment was the most common intervention (n = 21, 39%).

CONCLUSION

Biologic therapy increases the risk of rheumatic AEs in CRSwNP patients by over twofold. Healthcare providers should remain vigilant in monitoring rheumatic AEs and apply appropriate management strategies on a case-by-case basis.

Heterologous Prime-Boost with Immunologically Orthogonal Protein Nanoparticles for Peptide Immunofocusing

Protein nanoparticles are effective platforms for antigen presentation and targeting effector immune cells in vaccine development. Encapsulins are a class of protein-based microbial nanocompartments that self-assemble into icosahedral structures with external diameters ranging from 24 to 42 nm. Encapsulins from Myxococcus xanthus were designed to package bacterial RNA when produced in E. coli and were shown to have immunogenic and self-adjuvanting properties enhanced by this RNA. We genetically incorporated a 20-mer peptide derived from a mutant strain of the SARS-CoV-2 receptor binding domain (RBD) into the encapsulin protomeric coat protein for presentation on the exterior surface of the particle, inducing the formation of several nonicosahedral structures that were characterized by cryogenic electron microscopy. This immunogen elicited conformationally relevant humoral responses to the SARS-CoV-2 RBD. Immunological recognition was enhanced when the same peptide was presented in a heterologous prime/boost vaccination strategy using the engineered encapsulin and a previously reported variant of the PP7 virus-like particle, leading to the development of a selective antibody response against a SARS-CoV-2 RBD point mutant. While generating epitope-focused antibody responses is an interplay between inherent vaccine properties and B/T cells, here we demonstrate the use of orthogonal nanoparticles to fine-tune the control of epitope focusing.

Advanced in immunological monitoring of HIV infection: profile of immune cells and cytokines in people living with HIV-1 in Benin

BACKGROUND

Immune cells and cytokines have been linked to viremia dynamic and immune status during HIV infection. They may serve as useful biomarkers in the monitoring of people living with HIV-1 (PLHIV-1). The present work was aimed to assess whether cytokines and immune cell profiles may help in the therapeutic follow-up of PLHIV-1.

METHODS

Forty PLHIV-1 in treatment success (PLHIV-1s) and fifty PLHIV-1 in treatment failure (PLHIV-1f) followed at the University Hospital of Abomey-Calavi/Sô-Ava in Benin were enrolled. Twenty healthy persons were also recruited as control group. Circulating cytokines and immune cells were quantified respectively by ELISA and flow cytometry.

RESULTS

PLHIV-1 exhibited low proportions of CD4 + T cells, NK, NKT, granulocytes, classical and non-classical monocytes, and high proportions of CD8 + T cells, particularly in the PLHIV-1f group, compared to control subjects. Eosinophils, neutrophils and B cell frequencies did not change between the study groups. Circulating IFN-γ decreased whereas IL-4 significantly increased in PLHIV-1s compared to PLHIV-1f and control subjects even though the HIV infection in PLHIV-1s downregulated the high Th1 phenotype observed in control subjects. However, Th1/Th2 ratio remained biased to a Th1 phenotype in PLHIV-1f, suggesting that high viral load may have maintained a potential pro-inflammatory status in these patients. Data on inflammatory cytokines showed that IL-6 and TNF-α concentrations were significantly higher in PLHIV-1s and PLHIV-1f groups than in control subjects. Significant high levels of IL-5 and IL-7 were observed in PLHIV-1f compared to controls whereas PLHIV-1s presented only a high level of IL-5. No change was observed in IL-13 levels between the study groups.

CONCLUSION

Our study shows that, in addition to CD4/CD8 T cell ratio, NK and NKT cells along with IL-6, TNF-α, IL-5 and IL-7 cytokines could serve as valuable immunological biomarkers in the therapeutic monitoring of PLHIV-1 although a larger number of patients would be necessary to confirm these results.

Impact of dupilumab across seasons in patients with type 2, uncontrolled, moderate-to-severe asthma

BACKGROUND

Seasonal variability could influence asthma exacerbations. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin (IL)-4/IL-13, key and central drivers of type 2 inflammation. In the 52-week QUEST study (NCT02414854), add-on dupilumab every 2 weeks vs placebo significantly reduced exacerbations and improved prebronchodilator forced expiratory volume in 1 second in patients with uncontrolled, moderate-to-severe asthma. TRAVERSE (NCT02134028), the open-label QUEST extension study, enrolled patients with moderate-to-severe asthma to investigate long-term safety and efficacy of dupilumab, including patients who previously received placebo that initiated dupilumab therapy.

OBJECTIVE

To investigate long-term dupilumab efficacy in reducing exacerbations across yearly seasons in patients with type 2 inflammatory asthma with and without clinical evidence of allergic asthma.

METHODS

Unadjusted annualized exacerbation rate and proportions of patients experiencing severe asthma exacerbations are reported by month and season and for both hemispheres.

RESULTS

The proportion of patients with type 2 asthma experiencing 1 or more severe asthma exacerbations during QUEST was 20.8% vs 10.0% in spring, 18.2% vs 7.3% in summer, 22.2% vs 12.6% in autumn, and 26.4% vs 12.0% in winter, for placebo- vs dupilumab-treated patients, respectively; P was less than .001 for placebo vs dupilumab in all seasons. Reductions in the proportion of patients experiencing severe exacerbations across seasons in subgroups with and without evidence of allergic asthma were similar to the overall type 2 population. Reductions in severe exacerbations observed during QUEST were sustained during TRAVERSE, up to 96 weeks across both hemispheres.

CONCLUSION

Dupilumab reduced asthma exacerbations, with no difference in the reduction between seasons, in patients with type 2 inflammation, with and without evidence of allergic asthma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT02414854, NCT02134028.

Heterologous Prime-Boost with Immunologically Orthogonal Protein Nanoparticles for Peptide Immunofocusing

Protein nanoparticles are effective platforms for antigen presentation and targeting effector immune cells in vaccine development. Encapsulins are a class of protein-based microbial nanocompartments that self-assemble into icosahedral structures with external diameters ranging from 24 to 42 nm. Encapsulins from Mxyococcus xanthus were designed to package bacterial RNA when produced in E. coli and were shown to have immunogenic and self-adjuvanting properties enhanced by this RNA. We genetically incorporated a 20-mer peptide derived from a mutant strain of the SARS-CoV-2 receptor binding domain (RBD) into the encapsulin protomeric coat protein for presentation on the exterior surface of the particle. This immunogen elicited conformationally-relevant humoral responses to the SARS-CoV-2 RBD. Immunological recognition was enhanced when the same peptide was presented in a heterologous prime/boost vaccination strategy using the engineered encapsulin and a previously reported variant of the PP7 virus-like particle, leading to the development of a selective antibody response against a SARS-CoV-2 RBD point mutant. While generating epitope-focused antibody responses is an interplay between inherent vaccine properties and B/T cells, here we demonstrate the use of orthogonal nanoparticles to fine-tune the control of epitope focusing.

The Development of Human Ex Vivo Models of Inflammatory Skin Conditions

Traditional research in inflammatory dermatoses has relied on animal models and reconstructed human epidermis to study these conditions. However, these models are limited in replicating the complexity of real human skin and reproducing the intricate pathological changes in skin barrier components and lipid profiles. To address this gap, we developed experimental models that mimic various human inflammatory skin phenotypes. Human ex vivo skins were stimulated with various triggers, creating models for inflammation-induced angiogenesis, irritation response, and chronic T-cell activation. We assessed the alterations in skin morphology, cellular infiltrates, cytokine production, and epidermal lipidomic profiles. In the pro-angiogenesis model, we observed increased mast cell degranulation and elevated levels of angiogenic growth factors. Both the irritant and chronic inflammation models exhibited severe epidermal disruption, along with macrophage infiltration, leukocyte exocytosis, and heightened cytokine levels. Lipidomic analysis revealed minor changes in the pro-angiogenesis model, whereas the chronic inflammation and irritant models exhibited significant decreases in barrier essential ceramide subclasses and a shift toward shorter acyl chain lengths ( Collapse

Key Words

• ex vivo model
• skin barrier
• skin inflammation

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MESH Headings

• Animals
• Humans
• Irritants/pharmacology
• Skin/metabolism
• Epidermis/metabolism
• Skin Diseases/metabolism
• Inflammation/metabolism
• Cytokines/metabolism

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Affiliation(s)

Eddy Hsi Chun Wang L’Oreal Research and Innovation, Clark, NJ 07066, USA
Rebecca Barresi-Thornton L’Oreal Research and Innovation, Clark, NJ 07066, USA
Li-Chi Chen Harvard Medical School, Boston & Beth Israel Lahey Health, Burlington, MA 01805, USA
Maryanne Makredes Senna Harvard Medical School, Boston & Beth Israel Lahey Health, Burlington, MA 01805, USA
I-Chien Liao L’Oreal Research and Innovation, Clark, NJ 07066, USA
Ying Chen L’Oreal Research and Innovation, Clark, NJ 07066, USA
Qian Zheng L’Oreal Research and Innovation, Clark, NJ 07066, USA
Charbel Bouez L’Oreal Research and Innovation, Clark, NJ 07066, USA

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Collaborators Collapse

Evaluation of Proinflammatory Chemokines in HIV Patients with Asymptomatic Leishmania Infantum Infection

Asymptomatic Leishmania infantum, when associated with HIV, can become severe and potentially fatal. In this co-infection, the worst prognosis may be influenced by the host's immunological aspects, which are crucial in determining susceptibility. Chemokines play an important role in this process by influencing the cellular composition at affected sites and impacting the disease's outcome. Therefore, the aim of this study was to evaluate proinflammatory chemokines in HIV patients with the asymptomatic L. infantum infection. In this cross-sectional study, the levels of CCL2, CCL5, CXCL8, MIG, and IP-10 were measured in 160 serum samples from co-infected patients (n = 53), patients with HIV (n = 90), and negative controls (n = 17). Quantification was determined by flow cytometry. The obtained data were statistically analyzed using the Kruskal-Wallis test, followed by the Dunn's post-test and the Spearman's correlation coefficient. Significance was set at p < 0.05. The chemokines CCL2, CCL5, MIG, and IP-10 exhibited higher levels in the HIV group compared to co-infection. However, the elevated levels of all these chemokines and their increased connectivity in co-infected patients appear to be important in identifying proinflammatory immune responses associated with the asymptomatic condition. Furthermore, a weak negative correlation was observed between higher levels of CXCL8 and lower viral loads in co-infected patients.

CXCR5 and TIM-3 expressions define distinct exhausted T cell subsets in experimental cutaneous infection with Leishmania mexicana

T-cell exhaustion is a key stage in chronic infections since it limits immunopathology, but also hinders the elimination of pathogens. Exhausted T (Tex) cells encompass dynamic subsets, including progenitor cells that sustain long-term immunity through their memory/stem like properties, and terminally-differentiated cells, resembling the so-called Tex cells. The presence of Tex cells in chronic leishmaniasis has been reported in humans and murine models, yet their heterogeneity remains unexplored. Using flow cytometry, we identified Tex cells subtypes based on PD-1, CXCR5 and TIM-3 expressions in draining lymph nodes (dLNs) and lesion sites of C57BL/6 mice infected with L. mexicana at 30-, 60- and 90-days post-infection. We showed that infected mice developed a chronic infection characterized by non-healing lesions with a high parasite load and impaired Th1/Th2 cytokine production. Throughout the infection, PD-1+ cells were observed in dLNs, in addition to an enhanced expression of PD-1 in both CD4+ and CD8+ T lymphocytes. We demonstrated that CD4+ and CD8+ T cells were subdivided into PD-1+CXCR5+TIM-3- (CXCR5+), PD-1+CXCR5+TIM-3+ (CXCR5+TIM-3+), and PD-1+CXCR5-TIM-3+ (TIM-3+) subsets. CXCR5+ Tex cells were detected in dLNs during the whole course of the infection, whereas TIM-3+ cells were predominantly localized in the infection sites at day 90. CXCR5+TIM-3+ cells only increased at 30 and 60 days of infection in dLNs, whereas no increase was observed in the lesions. Phenotypic analysis revealed that CXCR5+ cells expressed significantly higher levels of CCR7 and lower levels of CX3CR1, PD-1, TIM-3, and CD39 compared to the TIM-3+ subset. CXCR5+TIM-3+ cells expressed the highest levels of all exhaustion-associated markers and of CX3CR1. In agreement with a less exhausted phenotype, the frequency of proliferating Ki-67 and IFN-γ expressing cells was significantly higher in the CXCR5+ subset within both CD4+ and CD8+ T cells compared to their respective TIM-3+ subsets, whereas CD8+CXCR5+TIM-3+ and CD8+TIM-3+ subsets showed an enhanced frequency of degranulating CD107a+ cells. In summary, we identified a novel, less-differentiated CXCR5+ Tex subset in experimental cutaneous leishmaniasis caused by L. mexicana. Targeting these cells through immune checkpoint inhibitors such as anti-PD-1 or anti PD-L1 might improve the current treatment for patients with the chronic forms of leishmaniasis.

Clinical and immunological spectra of human cutaneous leishmaniasis in North Africa and French Guiana

Cutaneous leishmaniasis (CL) caused by infection with the parasite Leishmania exhibits a large spectrum of clinical manifestations ranging from single healing to severe chronic lesions with the manifestation of resistance or not to treatment. Depending on the specie and multiple environmental parameters, the evolution of lesions is determined by a complex interaction between parasite factors and the early immune responses triggered, including innate and adaptive mechanisms. Moreover, lesion resolution requires parasite control as well as modulation of the pathologic local inflammation responses and the initiation of wound healing responses. Here, we have summarized recent advances in understanding the in situ immune response to cutaneous leishmaniasis: i) in North Africa caused by Leishmania (L.) major, L. tropica, and L. infantum, which caused in most cases localized autoresolutives forms, and ii) in French Guiana resulting from L. guyanensis and L. braziliensis, two of the most prevalent strains that may induce potentially mucosal forms of the disease. This review will allow a better understanding of local immune parameters, including cellular and cytokines release in the lesion, that controls infection and/or protect against the pathogenesis in new world compared to old world CL.

T cells in health and disease

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

Dual Interleukin-4/Interleukin-13 Blocker-induced Arthralgia Treated Successfully with Upadacitinib in a Patient with Atopic Dermatitis

Abstract is missing (Short communication)

Tumor heterogeneity: An oncogenic driver of PDAC progression and therapy resistance under stress conditions

Pancreatic ductal adenocarcinoma (PDAC) is a clinically challenging disease usually diagnosed at advanced or metastasized stage. By this year end, there are an expected increase in 62,210 new cases and 49,830 deaths in the United States, with 90% corresponding to PDAC subtype alone. Despite advances in cancer therapy, one of the major challenges combating PDAC remains tumor heterogeneity between PDAC patients and within the primary and metastatic lesions of the same patient. This review describes the PDAC subtypes based on the genomic, transcriptional, epigenetic, and metabolic signatures observed among patients and within individual tumors. Recent studies in tumor biology suggest PDAC heterogeneity as a major driver of disease progression under conditions of stress including hypoxia and nutrient deprivation, leading to metabolic reprogramming. We therefore advance our understanding in identifying the underlying mechanisms that interfere with the crosstalk between the extracellular matrix components and tumor cells that define the mechanics of tumor growth and metastasis. The bilateral interaction between the heterogeneous tumor microenvironment and PDAC cells serves as another important contributor that characterizes the tumor-promoting or tumor-suppressing phenotypes providing an opportunity for an effective treatment regime. Furthermore, we highlight the dynamic reciprocating interplay between the stromal and immune cells that impact immune surveillance or immune evasion response and contribute towards a complex process of tumorigenesis. In summary, the review encapsulates the existing knowledge of the currently applied treatments for PDAC with emphasis on tumor heterogeneity, manifesting at multiple levels, impacting disease progression and therapy resistance under stress.

The cytokine/chemokine response in Leishmania/HIV infection and co-infection

HIV infection progressively weakens the immune system by infecting and destroying cells involved in host defense. Viral infection symptoms are generated and aggravated as immunosuppression progresses, triggered by the presence of opportunistic infections: among these is leishmaniasis, a disease caused by the intracellular parasite Leishmania. The incidence of this co-infection is growing progressively due to the geographic distribution overlap. Both pathogens infect monocytes/macrophages and dendritic cells, although they can also modulate the activity of other cells without co-infecting, such as T and B lymphocytes. Leishmania/HIV co-infection could be described as a system comprising modulations of cell surface molecule expression, production of soluble factors, and intracellular death activities, leading ultimately to the potentiation of infectivity, replication, and spread of both pathogens. This review describes the cytokine/chemokine response in Leishmania/HIV infection and co-infection, discussing how these molecules modulate the course of the disease and analyzing the therapeutic potential of targeting this network.

IL-4/13 expressing CD3γ/δ+ T cells regulate mucosal immunity in response to Flavobacterium columnare infection in grass carp

Interleukin (IL) 4 and 13 are signature cytokines orchestrating Th2 immune response. Teleost fish have two homologs, termed IL-4/13A and IL-4/13B, and have been functionally characterized. However, what cells express IL-4/13A and IL-4/13B has not been investigated in fish. In this work, the recombinant IL-4/13A and IL-4/13B proteins of grass carp (Ctenopharyngodon idella) were produced in the Escherichia coli (E. coli) cells and purified. Monoclonal antibodies (mAbs) against the recombinant CiIL-4/13A and CiIL-4/13B proteins were prepared and characterized. Western blotting analysis showed that the CiIL-4/13A and CiIL-4/13B mAbs could specifically recognize the recombinant proteins expressed in the E. coli cells and HEK293T cells and did not cross-react with each other. Confocal microscopy revealed that the CiIL-4/13A⁺ and CiIL-4/13B⁺ cells were present in the gills, intestine and spleen and could be upregulated in fish infected with Flavobacterium columnare (F. columnare). Interestingly, the cells expressing CiIL-4/13A and CiIL-4/13B were mostly CD3γ/δ⁺ cells. The CD3γ/δ⁺/IL-4/13A⁺ and CD3γ/δ⁺/IL-4/13B⁺ cells were significantly upregulated in the gill filaments and the intestinal mucosa after F. columnare infection. Our results imply that the CD3γ/δ⁺/IL-4/13A⁺ and CD3γ/δ⁺/IL-4/13B⁺ cells are important for homeostasis and the regulation of mucosal immunity.

Setting a stage: Inflammation during preeclampsia and postpartum

Preeclampsia (PE) is a leading cause of maternal and fetal mortality worldwide. The immune system plays a critical role in normal pregnancy progression; however, inappropriate inflammatory responses have been consistently linked with PE pathophysiology. This inflammatory phenotype consists of activation of the innate immune system, adaptive immune system, and increased inflammatory mediators in circulation. Moreover, recent studies have shown that the inflammatory profile seen in PE persists into the postpartum period. This manuscript aims to highlight recent advances in research relating to inflammation in PE as well as the inflammation that persists postpartum in women after a PE pregnancy. With the advent of the COVID-19 pandemic, there has been an increase in obstetric disorders associated with COVID-19 infection during pregnancy. This manuscript also aims to shed light on the relationship between COVID-19 infection during pregnancy and the increased incidence of PE in these women.

Transforming growth factor receptor III (Betaglycan) regulates the generation of pathogenic Th17 cells in EAE

The transforming growth factor receptor III (TβRIII) is commonly recognized as a co-receptor that promotes the binding of TGFβ family ligands to type I and type II receptors. Within the immune system, TβRIII regulates T cell development in the thymus and is differentially expressed through activation; however, its function in mature T cells is unclear. To begin addressing this question, we developed a conditional knock-out mouse with restricted TβRIII deletion in mature T cells, necessary because genomic deletion of TβRIII results in perinatal mortality. We determined that TβRIII null mice developed more severe autoimmune central nervous neuroinflammatory disease after immunization with myelin oligodendrocyte peptide (MOG35-55) than wild-type littermates. The increase in disease severity in TβRIII null mice was associated with expanded numbers of CNS infiltrating IFNγ+ CD4+ T cells and cells that co-express both IFNγ and IL-17 (IFNγ+/IL-17+), but not IL-17 alone expressing CD4 T cells compared to Tgfbr3fl/fl wild-type controls. This led us to speculate that TβRIII may be involved in regulating conversion of encephalitogenic Th17 to Th1. To directly address this, we generated encephalitogenic Th17 and Th1 cells from wild type and TβRIII null mice for passive transfer of EAE into naïve mice. Remarkably, Th17 encephalitogenic T cells from TβRIII null induced EAE of much greater severity and earlier in onset than those from wild-type mice. The severity of EAE induced by encephalitogenic wild-type and Tgfbr3fl/fl.dLcKCre Th1 cells were similar. Moreover, in vitro restimulation of in vivo primed Tgfbr3fl/fl.dLcKCre T cells, under Th17 but not Th1 polarizing conditions, resulted in a significant increase of IFNγ+ T cells. Altogether, our data indicate that TβRIII is a coreceptor that functions as a key checkpoint in controlling the pathogenicity of autoreactive T cells in neuroinflammation probably through regulating plasticity of Th17 T cells into pathogenic Th1 cells. Importantly, this is the first demonstration that TβRIII has an intrinsic role in T cells.

Post-Translational Modifications in Atopic Dermatitis: Current Research and Clinical Relevance

Atopic dermatitis (AD) is a chronic and relapsing cutaneous disorder characterized by compromised immune system, excessive inflammation, and skin barrier disruption. Post-translational modifications (PTMs) are covalent and enzymatic modifications of proteins after their translation, which have been reported to play roles in inflammatory and allergic diseases. However, less attention has been paid to the effect of PTMs on AD. This review summarized the knowledge of six major classes (including phosphorylation, acetylation, ubiquitination, SUMOylation, glycosylation, o-glycosylation, and glycation) of PTMs in AD pathogenesis and discussed the opportunities for disease management.

Adeno-associated virus-mediated IL-12 gene expression alleviates lung inflammation and Th2-responses in OVA-sensitized asthmatic mice

High levels of allergen exposure increase the prevalence of asthma in development countries. The asthmatic Th2 response is characterized with high eosinophil infiltration, elevated Th2 cytokines and IgE secretion resulting in local or systemic inflammation. However, the treatment with palliative Th2 inhibitor drugs can't completely control asthma and that is why the development of novel approaches is still important. Based on Th1 and Th2 immune homeostasis, the enhanced Th1 immune response has high potential to alleviate Th2 immune response. Thus, we aimed to overexpress single chain IL-12 (scIL-12) via recombinant adeno-associated virus (rAAV) vector (as rAAV-IL-12) and test the efficacy in an ovalbumin (OVA)-induced asthmatic murine model. We firstly demonstrated the bioactivity of exogenous scIL-12. The expression of exogenous scIL-12 was also detected in the lungs of rAAV-IL-12 transduced mice. The data demonstrated that overexpression of exogenous scIL-12 significantly suppressed total cell numbers and eosinophil infiltration, as well as the mucus secretion in rAAV-IL-12-treated mice. The decreased OVA-specific IgE in bronchoalveolar lavage fluid (BALF) and gene expression of Th2-cytokines or CCL11 in lung were observed. In addition, the production of cytokines in the supernatants of OVA-stimulated splenocytes was suppressed with rAAV-IL-12 treatment. Thus, scIL-12 expression by rAAV vector was able to modulate Th2 activity and has the potential to be developed as a feasible strategy in modulating allergic diseases.

Effect of immunosuppression by UV-B radiation on components of the innate immune response in skin lesions with Leishmania mexicana: Effect of UVB on the innate immune response in cutaneous infection by L. mexicana

Cutaneous leishmaniasis is the most common form of leishmaniasis in humans, factors such as poverty, poor housing, inadequate domestic hygiene, malnutrition, mobility, and occupational exposure are risk factors associated with the condition, however, there are few studies focused on determining the immune mechanism involved in the resolution of cutaneous leishmaniasis caused by the species Leishmania mexicana, as well as possible environmental factors such as solar radiation, which could contribute to its establishment. through mechanisms immunosuppressants, of which to date is unknown. In this study, the effect of UV-B light was evaluated as a risk factor affecting components of the innate immune response 3 days after infection with L. mexicana. A delayed-type hypersensitivity reaction (DTH) was used to evaluate immunosuppression induced by UV-B light. Through a histological analysis, the skin lesions of the mice (Hematoxylin & Eosin) were evaluated, the presence of mast cells and their level of degranulation (toluidine blue staining), the presence of IL-10⁺ and MOMA2⁺ cells were analyzed by immunohistochemistry and finally, the cytokine profile was evaluated by qPCR in the skin lesions tissue. An alteration in the architecture of the tissue was observed, as well as a greater number of mast cells, both complete and degranulated, as well as an increase in IL-10⁺ and MOMA2⁺ cells in the skin lesions of the mice that were irradiated and subsequently infected, when compared with the lesions of infected mice (P> 0.0001), immunomodulation was also observed in the profile of cytokines expressed between both groups analyzed. This is the first study to demonstrate the effects of UV-B radiation on components of the innate immune response at short times of infection by L. mexicana.

Harnessing Antitumor CD4+ T Cells for Cancer Immunotherapy

Simple Summary

Diverse evidence revealed that CD4⁺ T cells play an important role in antitumor immunity by promoting or suppressing cytotoxic T cell responses. This review outlines the role of CD4⁺ T subsets within the tumor microenvironment and summarizes the latest progress regarding their potentials in cancer immunotherapy and methods for improving outcomes in cancer strategies by modulating CD4⁺ T responses.

Abstract

Over the past decades, CD4⁺ T cells have been considered as a supporting actor in the fields of cancer immunotherapy. Until recently, accumulating evidence has demonstrated the critical role of CD4⁺ T cells during antitumor immunity. CD4⁺ T cells can either suppress or promote the antitumor cytotoxic CD8⁺ T cell responses, either in secondary lymphoid organs or in the tumor. In this review, we provide an overview of the multifaceted role of different CD4⁺ T cell subsets in cancer immune response and their contribution during cancer therapies. Specifically, we focus on the latest progress regarding the impact of CD4⁺ T cell modulation on immunotherapies and other cancer therapies and discuss the prospect for harnessing CD4⁺ T cells to control tumor progression and prevent recurrence in patients.

Maternal nematode infection upregulates expression of Th2/Treg and diapedesis related genes in the neonatal brain

Intestinal nematode infections common during pregnancy have recently been shown to have impacts that extend to their uninfected offspring including altered brain gene expression. If maternal immune signals reach the neonatal brain, they might alter neuroimmune development. We explored expression of genes associated with four distinct types of T cells (Th1, Th2, Th17, Treg) and with leukocyte transendothelial migration and endocytosis transport across the blood–brain barrier (BBB) in the postnatal brain of offspring of nematode-infected mice, through secondary analysis of a whole brain gene expression database. Th1/Th17 expression was lowered by maternal infection as evidenced by down-regulated expression of IL1β, Th1 receptors and related proteins, and of IL22 and several Th17 genes associated with immunopathology. In contrast, Th2/Treg related pathways were upregulated as shown by higher expression of IL4 and TGF-β family genes. Maternal infection also upregulated expression of pathways and integrin genes involved in transport of leukocytes in between endothelial cells but downregulated endosome vesicle formation related genes that are necessary for endocytosis of immunoglobulins across the BBB. Taken together, pup brain gene expression indicates that maternal nematode infection enhanced movement of leukocytes across the neonatal BBB and promoted a Th2/Treg environment that presumably minimizes the proinflammatory Th1 response in the pup brain.

Immunological Traits of Patients with Coexistent Inflammatory Bowel Disease and Periodontal Disease: A Systematic Review

This systematic review assessed studies that evaluated the immunological traits of patients with both inflammatory bowel disease (IBD) and periodontal disease. An electronic search for literature was conducted on PubMed, Embase, Scopus, Cochrane and Web of Science. Studies that evaluated the immunological response in patients with IBD and periodontal disease were considered eligible for inclusion. A total of 6 cross-sectional studies of 275 patients were included. Immunological analyses were performed in gingival crevicular fluid, saliva, serum, intestinal and gingival biopsies. Four studies identified that the presence of IBD and periodontal disease was associated with higher levels of prostaglandin E2, aMMP8, IL-18 and S100A12, respectively, when compared to patients without the coexistence of both diseases. Furthermore, another study identified higher aMMP-8 levels with increasing severity of periodontitis in Crohn’s disease patients. The quality of overall evidence ranged from high to low due to the observational nature of contributing studies. The coexistence of IBD and periodontal disease seems to be associated with a more responsive inflammatory reaction compared with individuals having one or the other. More randomized controlled studies evaluating the coexistence of IBD and periodontitis are required to better explore the immunological interplay between them.

The balance between IL-12/IL4 in renal tissue switches the inflammatory response arm and shows relationship with the clinical signs in Leishmania-infected dogs

The pathogenesis of Canine leishmaniosis (CanL) is associated with altered cytokine expression and parasitic tissue shows a lot of inflammation. The aim of this study was to assess the renal inflammation and cytokine expression in eight symptomatic and eight asymptomatic Leishmania- infected dogs, and seven uninfected control dogs. Kidney fragments were stained with hematoxylin and eosin for morphometric evaluation. mRNA expression levels of interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-2, IL-4, IL-10, and IL-12 were assessed in the kidney fragments using quantitative real time-polymerase chain reaction. Inflammation, quantified by the average area of the infiltrated immune cells, was greater in symptomatic dogs than in those asymptomatic, whereas asymptomatic dogs exhibited higher inflammation than the control dogs (p > 0.05, Tukey's test). Expression levels of IFN-γ, TNF-α, IL-4, IL-10, and IL-12 were upregulated in symptomatic dogs and downregulated in asymptomatic dogs compared with those of the uninfected group. Furthermore, IL-4 showed higher expression in symptomatic dogs than in asymptomatic ones (p < 0.05, Mann-Whitney test), which was directly associated with clinical manifestations (p < 0.05, Chi-square test). However, IL-12 was predominantly expressed in symptomatic dogs, shifting the balance from IL-12/IL-4 to IL-12, which elicits a change in the inflammatory response. Leishmania was not found in the renal tissues in any one of the studied groups. Our data suggests that the balance between IL-12 and IL-4 plays an important role in the regulation of inflammation in renal tissue and clinical presentations in CanL.

Interleukin-4 increases phagocytosis of necrotic cells by macrophages through scavenger receptor CD36

OBJECTIVE

Interleukin-4 (IL-4) signalling pathways regulate the activity of macrophages, enhance their proteolytic capacity and drive resolution of inflammation during tissue repair. The aim of this study was to examine whether IL-4 can enhance phagocytosis of necrotic cells and elucidate the molecular mechanisms.

METHODS

Phagocytosis of necrotic thymocytes by RAW264.7 cells, a macrophage cell line, with or without IL-4 treatment, was determined by flow cytometry. Protein expression was determined by western blot analysis.

RESULTS

The phagocytosis index was significantly increased by IL-4 (10 ng/mL). IL-4-enhanced phagocytosis was mediated by upregulation of scavenger receptor CD36. STAT6 activation is required for IL-4-mediated phagocytosis.

CONCLUSIONS

Interleukin-4 can accelerate cell debris clearance by stimulating expression of CD36, which requires downstream STAT6 activation. Its beneficial effects on driving tissue repair and regeneration should be explored in future studies.

CD4+ T Cell Interstitial Migration Controlled by Fibronectin in the Inflamed Skin

The extracellular matrix (ECM) is extensively remodeled during inflammation providing essential guidance cues for immune cell migration and signals for cell activation and survival. There is increasing interest in the therapeutic targeting of ECM to mitigate chronic inflammatory diseases and enhance access to the tumor microenvironment. T cells utilize the ECM as a scaffold for interstitial migration, dependent on T cell expression of matrix-binding integrins αVβ1/αVβ3 and tissue display of the respective RGD-containing ligands. The specific ECM components that control T cell migration are unclear. Fibronectin (FN), a canonical RGD-containing matrix component, is heavily upregulated in inflamed tissues and in vitro can serve as a substrate for leukocyte migration. However, limited by lack of tools to intravitally visualize and manipulate FN, the specific role of FN in effector T cell migration in vivo is unknown. Here, we utilize fluorescently-tagged FN to probe for FN deposition, and intravital multiphoton microscopy to visualize T cell migration relative to FN in the inflamed ear dermis. Th1 cells were found to migrate along FN fibers, with T cells appearing to actively push or pull against flexible FN fibers. To determine the importance of T cell interactions with FN, we used a specific inhibitor of FN polymerization, pUR4. Intradermal delivery of pUR4 (but not the control peptide) to the inflamed skin resulted in a local reduction in FN deposition. We also saw a striking attenuation of Th1 effector T cell movement at the pUR4 injection site, suggesting FN plays a key role in T cell interstitial migration. In mechanistic studies, pUR4 incubation with FN in vitro resulted in enhanced tethering of T cells to FN matrix, limiting productive migration. In vivo, such tethering led to increased Th1 accumulation in the inflamed dermis. Enhanced Th1 accumulation exacerbated inflammation with increased Th1 activation and IFNγ cytokine production. Thus, our studies highlight the importance of ECM FN fibrils for T cell migration in inflamed tissues and suggest that manipulating local levels of ECM FN may prove beneficial in promoting T cell accumulation in tissues and enhancing local immunity to infection or cancer.

Type I hypersensitivity is induced in cattle PBMC during Bluetongue virus Taiwan isolate infection

Bluetongue is a fatal viral disease in ruminants and has serious economic impacts on the livestock industry. Interactions between bluetongue virus (BTV) and immune cells are interesting because of the unique scenarios in each combination of animal species/breed and viral virulence/serotype. This study investigated the immune response in bovine peripheral blood mononuclear cells (PBMC) infected by the BTV2 Taiwan strain. The replication of the virus was limited in monocytes and monocyte-derived macrophages (MDM), and lymphocytes were less permissive. The cytokine mRNA of IL-4 in PBMC was expressed earlier and in greater quantities than that of innate immunity (TNFα, IL-1β) and cell mediated immunity (CMI) (IFNγ), and the IL-4 protein was stably present in the culture medium until 72 h post-infection (hpi). Even in MDM reconstituted with autologous lymphocyte (MDM-Lymphocyte), the IL-4 still had high mRNA expression level. The level of IgE antibody also increased at 24-72 hpi, suggestive of the engagement of type I hypersensitivity in the pathogenesis. The anti-viral activity contained in the culture supernatant was transferrable to recipient infected PBMC from other cows. However, in infected MDM largely free of lymphocytes, mRNA expressions of IL-1β, TNFα and IL-12p40 were normally expressed from 6 to 48 hpi, supporting the notion that IL-4 elaborated by lymphocytes in PBMC mediated the inhibition of both innate immunity and CMI to BTV2. The sum of responses subsequent to the early IL-4 expression likely constitutes part of the unique scenario in the current BTV2-Cow experimental combination biased toward Th2 response.

Antileishmanial activity of Urtica dioica extract against zoonotic cutaneous leishmaniasis

BACKGROUND

Neglected parasitic diseases (NTDs) like cutaneous leishmaniasis (CL) have caused high mortality and morbidity rate in developing countries. This disease is considered as one of the six major tropical diseases, and has a great importance in HIV infected individuals as an opportunistic infection in those areas that both infections are endemic. This study evaluated the therapeutic effects of the Urtica dioica L (U. dioica) aqueous extract as an anti-leishmanial herbal drug in-vitro and in-vivo, and in addition to that, evaluated two vital immune system cytokines including gamma interferon (IFN-γ) and interleukin-4 (IL-4) plus nitric oxide (NO) and arginase activity against Leishmania major (L. major) infected mice.

METHODOLOGY/PRINCIPAL FINDINGS

In-vitro anti-leishmanial activity of U. dioica aqueous extract was determined using MTT method and also Parasite Rescue Transformation Assay. Also, the footpad lesion size and parasite load in BALB/c mice infected with L. major were quantified for in-vivo assessment. Furthermore, for evaluating the immune responses, the levels of IFN-γ, IL-4, NO and arginase were measured in the BALB/c mice. These results indicated that U. dioica extract significantly reduced the L. major promastigotes viability. According to the in-vitro cytotoxicity assay of the extract on Leishmania parasites (CC50) and infected macrophages (EC50), the extract had no toxicity to the macrophages, however it efficiently killed the L. major amastigotes. In addition, the lesion size, parasite load, IL-4, and ARG were decreased in the treated infected mice, however IFN-γ and NO were significantly increased.

CONCLUSIONS/SIGNIFICANCE

This study established satisfactory results in Leishmania parasite clearing both in-vivo and in-vitro. Therefore, U. dioica extract can be considered as an effective and harmless herbal compound for killing the parasite without toxicity to the host macrophages. Furthermore, it also can treat the CL by switching the mouse immune response towards a cell-mediated response (Th1); hence, it may be identified as a perfect therapeutic herbal drug for CL treatment.

Scaffold strategies for modulating immune microenvironment during bone regeneration

Implanted bone scaffolds often fail to successfully integrate with the host tissue because they do not elicit a favorable immune reaction. Properties of bone scaffold not only provide mechanical and chemical signals to support cell adhesion, migration, proliferation and differentiation, but also play a pivotal role in determining the extent of immune response during bone regeneration. Appropriate design parameters of bone scaffold are of great significance in the process of developing a new generation of bone implants. Herein, this article addresses the recent advances in the field of bone scaffolds for immune response, particularly focusing on the physical and chemical properties of bone scaffold in manipulating the host response. Furthermore, incorporation of bioactive molecules and cells with immunoregulatory function in bone scaffolds are also presented. Finally, continuing challenges and future directions of scaffold-based strategies for modulating immune microenvironment are discussed.

Viperin controls chikungunya virus-specific pathogenic T cell IFNγ Th1 stimulation in mice

This study shows that Viperin controls the microenvironment pro-inflammatory response and CD4 T cell–mediated pathogenesis during anti-chikungunya virus immune response in mice.

Chikungunya virus (CHIKV) has been a worldwide threat since its reemergence in La Reunion Island in 2004. Expression of the interferon-stimulated protein Viperin correlates with viral load burden in patients, and studies in mice have demonstrated its role to limit disease severity against CHIKV infection. Using Viperin^−/− mice, we aimed to understand the contribution of Viperin to the T-cell immune response against CHIKV. CD4 T-cell depletion in Viperin^−/− mice showed that increased late acute joint inflammation (5–8 d postinfection) was exclusively mediated by T cells. Specifically, CHIKV-infected Viperin^−/− mice showed an increased INFγ Th1 profile of CD4 T cells, enhanced INFγ stimulation by APCs, an increased INFγ secretion profile in the joint microenvironment, and increased numbers of inflammatory monocytes in virus-infected joints compared with WT mice. Bone marrow grafting experiments showed that Viperin expression in both hematopoietic and non-hematopoietic cells is instrumental in reducing disease severity associated with a CD4 T-cell response.

CCL7 Is a Negative Regulator of Cutaneous Inflammation Following Leishmania major Infection

The chemokine CCL7 (MCP3) is known to promote the recruitment of many innate immune cell types including monocytes and neutrophils to sites of bacterial and viral infection and eosinophils and basophils to sites of allergic inflammation. CCL7 upregulation has been associated with many inflammatory settings including infection, cardiovascular disease, and the tumor microenvironment. CCL7's pleotropic effects are due in part to its ability to bind numerous chemokine receptors, namely CCR1, CCR2, CCR3, CCR5, and CCR10. CCL7-blockade or CCL7-deficiency is often marked by decreased inflammation and poor pathogen control. In the context of Leishmania major infection, CCL7 is specifically upregulated in the skin one-2 weeks after infection but its role in L. major control is unclear. To determine CCL7's impact on the response to L. major we infected WT and CCL7^-/- C57BL/6 mice. L. major infection of CCL7-deficient mice led to an unexpected increase in inflammation in the infected skin 2 weeks post-infection. A broad increase in immune cell subsets was observed but was dominated by enhanced neutrophilic infiltration. Increased neutrophil recruitment was associated with an enhanced IL-17 gene profile in the infected skin. CCL7 was shown to directly antagonize neutrophil migration in vitro and CCL7 add-back in vivo specifically reduced neutrophil influx into the infected skin revealing an unexpected role for CCL7 in limiting neutrophil recruitment during L. major infection. Enhanced neutrophilic infiltration in CCL7-deficient mice changed the balance of L. major infected host cells with an increase in the ratio of infected neutrophils over monocytes/macrophages. To determine the consequence of CCL7 deficiency on L. major control we analyzed parasite load cutaneously at the site of infection and viscerally in the draining LN and spleen. The CCL7^-/- mice supported robust cutaneous parasite control similar to their WT C57BL/6 counterparts. In contrast, CCL7-deficiency led to greater parasite dissemination and poor parasite control in the spleen. Our studies reveal a novel role for CCL7 in negatively regulating cutaneous inflammation, specifically neutrophils, early during L. major infection. We propose that CCL7-mediated dampening of the early immune response in the skin may limit the ability of the parasite to disseminate without compromising cutaneous control.

Tailoring the homing capacity of human Tregs for directed migration to sites of Th1-inflammation or intestinal regions

Cell-based therapy with CD4⁺ FOXP3⁺ regulatory T cells (Tregs) is a promising strategy to limit organ rejection and graft-vs-host disease. Ongoing clinical applications have yet to consider how human Tregs could be modified to direct their migration to specific inflammation sites and/or tissues for more targeted immunosuppression. We show here that stable, homing-receptor-tailored human Tregs can be generated from thymic Tregs isolated from pediatric thymus or adult blood. To direct migration to Th1-inflammatory sites, addition of interferon-γ and IL-12 during Treg expansion produced suppressive, epigenetically stable CXCR3⁺ TBET⁺ FOXP3⁺ T helper (Th)1-Tregs. CXCR3 remained expressed after injection in vivo and Th1-Tregs migrated efficiently towards CXCL10 in vitro. To induce tissue-specific migration, addition of retinoic acid (RA) during Treg expansion induced expression of the gut-homing receptors α4β7-integrin and CCR9. FOXP3⁺ RA-Tregs had elevated expression of the functional markers latency-associated peptide and glycoprotein A repetitions predominant, increased suppressive capacity in vitro and migrated efficiently to healthy and inflamed intestine after injection into mice. Homing-receptor-tailored Tregs were epigenetically stable even after long-term exposure to inflammatory conditions, suppressive in vivo and characterized by Th1- or gut-homing-specific transcriptomes. Tailoring human thymic Treg homing during in vitro expansion offers a new and clinically applicable approach to improving the potency and specificity of Treg therapy.

Upregulation of Cardiac IL-10 and Downregulation of IFN-γ in Balb/c IL-4-/- in Acute Chagasic Myocarditis due to Colombian Strain of Trypanosoma cruzi

Inflammatory response in Chagas disease is related to parasite and host factors. However, immune system regulation has not been fully elucidated. Thus, this study is aimed at evaluating IL-4 influence on acute phase of Trypanosoma cruzi experimental infection through dosage of cytokine levels in cardiac homogenate of infected Balb/c WT and Balb/c IL-4^−/− as well as its histopathological repercussions. For such purpose, mice were divided into two groups: an infected group with 100 forms of the Colombian strain and an uninfected group. After 21 days of infection, animals were euthanized and the blood, spleen, and heart were collected. The spleen was used to culture splenic cells in 48 h. Subsequently, cytokines TNF-α, IL-12p70, IL-10, IFN-γ, and IL-17 were measured in the blood, culture supernatant, and heart apex by ELISA. The base of the heart was used for histopathological analysis. From these analysis, infected Balb/c IL-4^−/− mice showed milder inflammatory infiltrate compared to Balb/c WT, but without changes in nest density and collagen deposition. IL-4 absence culminated in lower cardiac tissue IFN-γ production, although it did not affect TNF-α expression in situ. It also decreased TNF-α systemic production and increased IL-10, both systemically and in situ. In addition, IL-4 absence did not influence IL-17 expression. Splenocytes of IL-4-deficient mice produced higher amounts of IFN-γ, TNF-α, and IL-17 and lower amounts of IL-10. Thus, IL-4 absence in acute phase of experimental infection with T. cruzi Colombian strain reduces myocarditis due to lower IFN-γ production and greater IL-10 production in situ and this pattern is not influenced by splenocyte general repertoire.

The Role of CXCR3 and Its Chemokine Ligands in Skin Disease and Cancer

Chemokines and their receptors play an important role in the recruitment, activation and differentiation of immune cells. The chemokine receptor, CXCR3, and its ligands, CXCL9, CXCL10, and CXCL11 are key immune chemoattractants during interferon-induced inflammatory responses. Inflammation of the skin resulting from infections or autoimmune disease drives expression of CXCL9/10/11 and the subsequent recruitment of effector, CXCR3⁺ T cells from the circulation. The relative contributions of the different CXCR3 chemokines and the three variant isoforms of CXCR3 (CXCR3A, CXCR3B, CXCR3alt) to the inflammatory process in human skin requires further investigation. In skin cancers, the CXCR3 receptor can play a dual role whereby expression on tumor cells can lead to cancer metastasis to systemic sites while receptor expression on immune cells can frequently promote anti-tumor immune responses. This review will discuss the biology of CXCR3 and its associated ligands with particular emphasis on the skin during inflammation and carcinogenesis.

Live Leishmania tarentolae secreting HNP1 as an immunotherapeutic tool against Leishmania infection in BALB/c mice

AIM

Several disadvantages about chemotherapy for leishmaniasis has reinforced discovery of novel therapeutic agents especially immunotherapeutics. HNP1, as a member of the mammalian antimicrobial peptides family, is an attractive molecule due to its broad functional spectrum. Here, the in vivo potency of HNP1 in transgenic Leishmania tarentolae as an immunotherapy tool against Leishmania major-infected BALB/c mice was examined.

METHODS & RESULTS

3 weeks after infection with L. major, the treatment effect of L. tarentolae-HNP1-EGFP was pursued. The results were promising in respect to parasite load control and Th1 immune response polarization compared with controls.

CONCLUSION

Immunotherapy by live L. tarentolae secreting HNP1 can elicit cellular immune response in a susceptible mouse model in order to control L. major infection.

Baicalin Downregulates RLRs Signaling Pathway to Control Influenza A Virus Infection and Improve the Prognosis

The objective of this study is to investigate the effects of baicalin on controlling the pulmonary infection and improving the prognosis in influenza A virus (IAV) infection. PCR and western blot were used to measure the changes of some key factors in RLRs signaling pathway. MSD electrochemiluminescence was used to measure the expression of pulmonary inflammatory cytokines including IFN-γ, TNF-α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, and KC/GRO. Flow cytometry was used to detect the proportion of Th1, Th2, Th17, and Treg. The results showed that IAV infection led to low body weight and high viral load and high expression of RIG-I, IRF3, IRF7, and NF-κB mRNA, as well as RIG-I and NF-κB p65 protein. However, baicalin reduced the rate of body weight loss, inhibited virus replication, and downregulated the key factors of the RLRs signaling pathway. Besides, baicalin reduced the high expression inflammatory cytokines in lung and decreased the ratios of Th1/Th2 and Th17/Treg to arouse a brief but not overviolent inflammatory response. Therefore, baicalin activated a balanced host inflammatory response to limit immunopathologic injury, which was helpful to the improvement of clinical and survival outcomes.

Host-parasite Responses Outcome Regulate the Expression of Antimicrobial Peptide Genes in the Skin of BALB/c and C57BL/6 Murine Strains Following Leishmania major MRHO/IR/75/ER Infection

BACKGROUND

Different background of immunity responses determine resistance or susceptibility of certain mouse strains to Leishmania major infection. Some have been well known previously. Antimicrobial peptides (AMPs) such as cathelicidins and defensins are unique fragments of innate immunity system with well-known effects against the invasion pathogens. Despite their outstanding roles and being of extensive cases of cutaneous leishmaniasis (CL) caused by L. major, they have been less studied in Leishmania fields. The aim of present study was to determine whether these components play a role in the protection of skin against Leishmania infections.

METHODS

The animal model of Leishmania infection was established by the subcutaneous inoculation of 5×10⁶(parasites/ml) from the stationary phase of L. major promastigotes to BALB/c and C57BL/6 mice from January 2016 to August 2016 in Kerman Province, southeast of Iran. After 1, 3 and 7 d of post-infection (PI), the samples needed for detecting of the mRNA levels of mouse beta-defensin (mBD)-1, mBD2, mBD3, mBD4, mBD6, cathlin-related antimicrobial peptide (CRAMP), interleukin (IL)-10, IL-12 and parasite load were taken under standard methods.

RESULTS

The findings related to cytokines profiles in BALB/c (↑IL-10, ↓IL-12) and C57BL/6 mouse strains (↓IL-10, ↑IL-12) demonstrated that immunity system has been accurately activated during CL caused by L. Major parasites. We also observed a significant up-regulation of all aforementioned AMPs genes in BALB/c mice at selected times compared to another strain.

CONCLUSION

CL occurred in BALB/c mice in spite of the fact that the expression of AMPs was higher than the other strain. AMPs genes are well expressed to provide defense against the parasites that have increased and escaped from immunity system but cannot create an absolute protection.

Human Neutrophil Peptide 1 as immunotherapeutic agent against Leishmania infected BALB/c mice

Human Neutrophil Peptide 1 (HNP1) produced by neutrophils, is a well-known antimicrobial peptide which plays a role both in innate as well as in adaptive immunity and is under intensive investigation as a potential therapeutic agent. Previous in vitro experiments have indicated the leishmaniacidal effect of recombinant HNP1 on Leishmania major (L. major) promastigotes and amastigotes. In the current study, we further extended the idea to explore the remedial effect of HNP1 in the two modalities of peptide therapy (folded HNP1) and gene therapy in L. major infected BALB/c mice. To this end, mice in five different groups received synthetic folded HNP1 (G1), pcDNA-HNP1-EGFP (G2), pcDNA-EGFP (G3), Amphotericin B (G4) and PBS (G5), which was started three weeks after infection for three consecutive weeks. Footpad swelling was monitored weekly and a day after the therapy ended, IFN-γ, IL-4, IL-10, IL-6 and nitric oxide produced by splenocytes were analyzed together with the parasite load in draining lymph nodes. Arginase activity and dermal histopathological changes were also analyzed in the infected footpads. We demonstrated that both therapeutic approaches effectively induced Th1 polarization and restricted parasite burden. It can control disease progression in contrast to non-treated groups. However, pcDNA-HNP1-EGFP is more promising in respect to parasite control than folded HNP1, but less effective than AmB treatment. We concluded with the call for a future approach, that is, a DNA-based expression of HNP1 combined with AmB as it can improve the leishmaniacidal efficacy.

The outbreak level of cutaneous leishmaniasis is approximated between one and 1.5 million individuals per year. Owning to several disadvantages of current therapies, special attention to expand novel and efficient therapies has been demanded. Among Anti-Microbial Peptides (AMPs), Human Neutrophil Peptide 1 (HNP1) is one of the most potential defensins. Our promising in vitro experiments have shown the leishmaniacidal effect of recombinant HNP1. Here, we displayed the remedial effect of HNP1 in two approaches including peptide therapy and gene therapy in susceptible mice infected with L. major. Our investigation showed that although both approaches could decrease the parasite load and induce Th1 immune response compared to the control group, pcDNA-HNP1-EGFP has a better effect compared to the folded HNP1. Hence, immunotherapy by HNP1 can help elicit proper immunity despite the direct effect on promastigotes and amastigotes forms of parasite.

Mannose receptor high, M2 dermal macrophages mediate nonhealing Leishmania major infection in a Th1 immune environment

The origin and functional specialization of dermal macrophages in cutaneous infections have been little studied. In this paper, we show that a strain of Leishmania major (L. major Seidman [LmSd]) that produces nonhealing cutaneous lesions in conventionally resistant C57BL/6 mice was more efficiently taken up by M2-polarized bone marrow (BM)-derived macrophages (BMDMs) in vitro and by mannose receptor (MR)^hi dermal macrophages in vivo compared with a healing strain (L. major Friedlin V1). Both in steady and in T helper type 1 (Th1) cell-driven inflammatory states, the MR^hi dermal macrophages showed M2 characteristics. The dermal macrophages were radio resistant and not replaced by monocytes or adult BM-derived cells during infection, but were locally maintained by IL-4 and IL-10. Notably, the favored infection of M2 BMDMs by LmSd in vitro was MR dependent, and genetic deletion of MR or selective depletion of MR^hi dermal macrophages by anti-CSF-1 receptor antibody reversed the nonhealing phenotype. We conclude that embryonic-derived, MR^hi dermal macrophages are permissive for parasite growth even in a strong Th1-immune environment, and the preferential infection of these cells plays a crucial role in the severity of cutaneous disease.