Praziquantel Reduces Maternal Mortality and Offspring Morbidity by Enhancing Anti-Helminthic Immune Responses

Alongside the wide distribution throughout sub Saharan Africa of schistosomiasis, the morbidity associated with this chronic parasitic disease in endemic regions is often coupled with infection-driven immunomodulatory processes which modify inflammatory responses. Early life parasite exposure is theorized to drive immune tolerance towards cognate infection as well as bystander immune responses, beginning with in utero exposure to maternal infection. Considering that 40 million women of childbearing-age are at risk of infection worldwide, treatment with Praziquantel during pregnancy as currently recommended by WHO could have significant impact on disease outcomes in these populations. Here, we describe the effects of anthelminthic treatment on parasite-induced changes to fetomaternal cross talk in a murine model of maternal schistosomiasis. Praziquantel administration immediately prior to mating lead to clear re-awakening of maternal anti-parasite immune responses, with persistent maternal immune activation that included enhanced anti-schistosome cytokine responses. Clearance of parasites also improved capacity of dams to endure the additional pressure of pregnancy during infection. Maternal treatment also drove lasting functional alterations to immune system development of exposed offspring. Prenatal anthelminthic treatment skewed offspring immune responses towards parasite clearance and reduced morbidity during cognate infection. Maternal treatment also restored offspring protective IgE antibody responses directed against schistosome antigens, which were otherwise suppressed following exposure to untreated maternal infection. This was further associated with enhanced anti-schistosome cytokine responses from treatment-exposed offspring during infection. In the absence of cognate infection, exposed offspring further demonstrated imprinting across cellular populations. We provide further evidence that maternal treatment can restore a more normalized immune profile to such offspring exposed in utero to parasite infection, particularly in B cell populations, which may underlie improved responsiveness to cognate infection, and support the WHO recommendation of anthelminthic treatment during pregnancy.

Elevated osteopontin and IFNy serum levels and increased neutrophil-to-lymphocyte ratio are associated with the severity of symptoms in schizophrenia

Introduction

Inflammation and immune dysregulation could contribute to the pathogenesis of schizophrenia. Osteopontin (OPN) is a key cytokine-like molecule in cellular immune response and it can directly modulate the cytokine expression and survival of microglia. Furthermore, its mRNA expression is elevated in first episode psychosis. Imbalance of T-helper subtypes could also represent a vulnerability factor for schizophrenia.

Objectives

The aim of this study was to evaluate the relevance of T-helper subtype associated cytokines, OPN and NLR in the assessment of the severity of schizophrenia.

Methods

22 patients with schizophrenia were assessed for the intensity of their symptoms by PANSS and CGI scores. Serum OPN, IFNy, IL-10 and IL-8 concentrations were measured by ELISA kits and NLR was calculated from blood count. Statistical evaluation was performed using Mann-Whitney U test, Student’s t test and Spearman correlation.

Results

We found significant correlation between the level of OPN and PANSS-total, PANSS-general scores. IFNy level and NLR showed significant correlation with PANSS-total, PANSS-positive, PANSS-general and CGI score. Antipsychotic therapy only had significant effects on NLR and OPN levels, both of which were significantly reduced after long-term antipsychotic treatment.

Conclusions

Our results indicate that elevated OPN and IFNy concentrations, and increased NLR are associated with severe symptoms in schizophrenia and suggest the importance of Th1 subtype in patients with high PANSS-positive and PANSS-general score. Antipsychotic treatment had significant effects on the level of OPN and NLR, but not on the level of IFNy. Overall our results strengthen the inflammation hypothesis of schizophrenia.

Disclosure

No significant relationships.

Regulatory T cells are less sensitive to glucocorticoid hormone induced apoptosis than CD4+ T cells

Earlier we have reported that thymic regulatory T cells (Treg) are resistant to in vivo glucocorticoid hormone (GC)-induced apoptosis, while the most GC-sensitive DP thymocytes died through the activation of mitochondrial apoptotic pathway. Here we analyzed the apoptosis-inducing effect of high dose (10^-6 M) in vitro dexamethasone (DX) treatment in mouse thymic- and splenic Tregs and CD4⁺ T cells. Activation of both extrinsic and intrinsic apoptotic pathways started after 2 h of DX treatment in CD4 SP thymocytes and was 3 × higher than in CD4⁺ splenocytes, while in Treg cells, weak activation of the extrinsic apoptotic pathway started only after 3 h. We also investigated the expression of 21 apoptosis-related molecules using a protein array and found higher level of both pro-and anti-apoptotic molecules in Tregs compared to CD4⁺ T cells. 4 h in vitro DX treatment induced upregulation of most apoptosis-related molecules both in Tregs and CD4⁺ T cells, except for the decrease of Bcl-2 expression in CD4⁺ T cells. We found high basal cytosolic Ca²⁺ levels in untreated Treg cells, which further increased after DX treatment, while the specific TCR-induced Ca²⁺ signal was lower in Tregs than in CD4⁺ T cells. Our results suggest that in the background of the relative apoptosis resistance of Treg cells to GCs might be their high basal cytosolic Ca²⁺ level and upregulated Bcl-2 expression. In contrast, downregulation of Bcl-2 expression in CD4⁺ T cells can explain their higher, DX-induced apoptosis sensitivity.

ZAP-70 Regulates Autoimmune Arthritis via Alterations in T Cell Activation and Apoptosis

T cells play an essential role in the pathogenesis of both human rheumatoid arthritis (RA) and its murine models. A key molecule in T cell activation is ZAP-70, therefore we aimed to investigate the effects of partial ZAP-70 deficiency on the pathogenesis of recombinant human G1(rhG1)-induced arthritis (GIA), a well-established mouse model of RA. Arthritis was induced in BALB/c and ZAP-70^+/- heterozygous mice. Disease progression was monitored using a scoring system and in vivo imaging, antigen-specific proliferation, cytokine and autoantibody production was measured and T cell apoptotic pathways were analyzed. ZAP-70^+/- mice developed a less severe arthritis, as shown by both clinical picture and in vitro parameters (decreased T cell proliferation, cytokine and autoantibody production). The amount of cleaved Caspase-3 increased in arthritic ZAP-70^+/- T cells, with no significant changes in cleaved Caspase-8 and -9 levels; although expression of Bim, Bcl-2 and Cytochrome C showed alterations. Tyrosine phosphorylation was less pronounced in arthritic ZAP-70^+/- T cells and the amount of Cbl-b-a negative regulator of T cell activation-decreased as well. We hypothesize that the less severe disease seen in the partial absence of ZAP-70 might be caused by the decreased T cell activation accompanied by increased apoptosis.

Elevated Osteopontin and Interferon Gamma Serum Levels and Increased Neutrophil-to-Lymphocyte Ratio Are Associated With the Severity of Symptoms in Schizophrenia

Inflammation and immune dysregulation could contribute to the pathogenesis of schizophrenia. Osteopontin (OPN) is a cytokine-like glycoprotein involved in inflammation and in modulating immune responses, and it can also directly modify the cytokine expression and survival of microglia. Furthermore, elevated gene expression of OPN in first episode psychosis has recently been described, but to date OPN level has not been investigated in schizophrenia. Imbalance of T-helper subtypes could also represent a vulnerability factor for schizophrenia. In this study, we analyzed the concentration of OPN, levels of cytokines associated with T-helper subtypes: interferon gamma (IFNy) for Th1, interleukin (IL)-10 for Th2, IL-8 for Th17, and neutrophil-to-lymphocyte ratio (NLR) in 22 patients with schizophrenia assessed for the intensity of their symptoms by the Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impression scale (CGI) scores. Serum OPN, IFNy, IL-10, and IL-8 concentrations were measured by ELISA kits and NLR was calculated from blood count. We found significant correlation between the level of OPN and PANSS-total and PANSS-general scores. IFNy level and NLR showed significant correlation with PANSS-total, PANSS-positive, PANSS-general, and CGI score. Among the measured markers antipsychotic therapy only had significant effects on NLR and OPN level, both of which were significantly reduced after long-term antipsychotic treatment. Our results indicate that elevated OPN and IFNy concentrations, and increased NLR are associated with severe symptoms in schizophrenia and suggest the importance of Th1 subtype in patients with high PANSS-positive and PANSS-general subscore. Significant correlation between NLR and PANSS scores strengthens the inflammation hypothesis of schizophrenia.

Correction of T cell deficiency in ZAP-70 knock-out mice by simple intraperitoneal adoptive transfer of thymocytes

The tyrosine kinase zeta chain-associated protein of 70 kDa (ZAP-70) plays a key role in T cell development and signalling. In the absence of ZAP-70, T cell development is arrested in the CD4⁺ CD8⁺ double-positive stage, thus ZAP-70 homozygous knockout (ZAP-70^-/- ) mice have no mature T cells in their peripheral lymphoid organs and blood, causing severe immunodeficiency. We investigated the early kinetics and long-term effects of wild-type thymocyte transfer on T cell repopulation in ZAP-70^-/- mice. We used a single intraperitoneal (i.p.) injection to deliver donor thymocytes to the recipients. Here, we show that after i.p. injection donor thymocytes leave the peritoneum through milky spots in the omentum and home to the thymus, where donor-originated CD4^- CD8^- double-negative thymocytes most probably restore T cell development and the disrupted thymic architecture. Subsequently, newly developed, donor-originated, single-positive αβ T cells appear in peripheral lymphoid organs, where they form organized T cell zones. The established chimerism was found to be stable, as donor-originated cells were present in transferred ZAP-70^-/- mice as late as 8 months after i.p. injection. We demonstrate that a simple i.p. injection of ZAP-70^+/+ thymocytes is a feasible method for the long-term reconstitution of T cell development in ZAP-70-deficient mice.