Infection by Schistosoma mansoni during pregnancy: Effects on offspring immunity

Fluorescent quantum dot-based nanotool for targeted identification and evaluation of the schistosomiasis circulating cathodic antigen in tissue samples

Schistosomiasis represents a serious public health problem, a disease for which the circulating cathodic antigen (CCA) is a relevant biomarker. Quantum dots (QDs) are advantageous fluorescent nanoparticles that can be used as specific nanoprobes. In this study, a nanotool based on QDs and anti-CCA antibodies was developed, which, in association with fluorescence microscopy, was applied to trace and evaluate the CCA profile in schistosomiasis-infected tissue samples. Kidney and liver tissues from mice at different disease phases were used as models. QDs and the conjugates were characterized by absorption and emission spectroscopies. Microscopy analyses were used to map and assess CCA accumulation in infected tissue slices in respect to non-infected control samples. The fluorescent microplate assay (FMA) and Zeta potential (ζ) analyses indicated an effective conjugation, which was corroborated by the absence of labeling in non-infected tissue slices (which lack CCA) after incubation with the nanoprobe. Infected liver and kidney tissues exhibited notable staining by the QDs-anti-CCA conjugate. The CCA accumulation increased as follows: 30 < 60 = 120 days post-infection, with 30, 60, and 120 days corresponding to the pre-patent, acute, and beginning of chronic disease phases, respectively. Therefore, this innovative approach, combining imaging acquisition with the sensitivity and specificity of the QDs-anti-CCA conjugate, demonstrated efficiency in locating and comparatively evaluating CCA deposition in biological samples, thereby opening new possibilities for schistosomiasis research.

A Mini-Review on Elisa-Based Diagnosis of Schistosomiasis

BACKGROUND

Schistosomiasis is a neglected tropical parasitic disease caused by trematode worms of the genus schistosoma, which affects approximately 240 million people worldwide. the diagnosis of the disease can be performed by parasitological, molecular, and/or immunological methods, however, the development of new diagnostic methods still essential to guide policy decisions, monitor disease trends and assess the effectiveness of interventions.

OBJECTIVE

in this sense, the current work summarizes the findings of a systematic review regarding antigens applied in the enzyme-linked immunosorbent assay test, which were patented and published over the last ten years.

METHODS

the literature search strategy used medical subject heading (mesh) terms to define as descriptors. "schistosoma mansoni" was used in arrangement with the descriptors "immunoassay", "enzyme-linked immunosorbent assay", "elisa", and "antigens", using the "and" connector. the patent search was done using keywords, including diagnosis and schistosoma or schistosomiasis or schistosome. several databases were employed for the patent search, such as intellectual property national institute; european patent office; the united states patent and trademark office; patent scope, and google patents.

RESULTS

forty-one articles were retrieved, of which only five met the eligibility criteria. seventeen patents were taken from the databases, and a brief description of the most relevant inventions is given here.

CONCLUSION

schistosomiasis is considered the most important helminthic disease in worldwide. therefore, it is important to of searching for and develops diagnostic methods based on serology to reduce morbidity and mortality caused by the disease.

The role of miRNA molecules in the miscarriage process

The etiology and pathogenesis of miscarriage, which is the most common pregnancy complication, have not been fully elucidated. There is a constant search for new screening biomarkers that would allow for the early diagnosis of disorders associated with pregnancy pathology. The profiling of microRNA expression is a promising research area, which can help establish the predictive factors for pregnancy diseases. Molecules of microRNAs are involved in several processes crucial for the development and functioning of the body. These processes include cell division and differentiation, programmed cell death, blood vessel formation or tumorigenesis, and the response to oxidative stress. The microRNAs affect the number of individual proteins in the body due to their ability to regulate gene expression at the post-transcriptional level, ensuring the normal course of many cellular processes. Based on the scientific facts available, this paper presents a compendium on the role of microRNA molecules in the miscarriage process. The expression of potential microRNA molecules as early minimally invasive diagnostic biomarkers may be evaluated as early as the first weeks of pregnancy and may constitute a monitoring factor in the individual clinical care of women in early pregnancy, especially after the first miscarriage. To summarize, the described scientific data set a new direction of research in the development of preventive care and prognostic monitoring of the course of pregnancy.

Epigenetic signature of exposure to maternal Trypanosoma cruzi infection in cord blood cells from uninfected newborns

Aims: To assess the epigenetic effects of in utero exposure to maternal Trypanosoma cruzi infection. Methods: We performed an epigenome-wide association study to compare the DNA methylation patterns of umbilical cord blood cells from uninfected babies from chagasic and uninfected mothers. DNA methylation was measured using Infinium EPIC arrays. Results: We identified a differential DNA methylation signature of fetal exposure to maternal T. cruzi infection, in the absence of parasite transmission, with 12 differentially methylated sites in B cells and CD4⁺ T cells, including eight protein-coding genes. Conclusion: These genes participate in hematopoietic cell differentiation and the immune response and may be involved in immune disorders. They also have been associated with several developmental disorders and syndromes.

Serology- and Blood-PCR-Based Screening for Schistosomiasis in Pregnant Women in Madagascar-A Cross-Sectional Study and Test Comparison Approach

This work was conducted as a cross sectional study to define the disease burden of schistosomiasis in pregnant Madagascan women and to evaluate serological and molecular diagnostic assays. A total of 1154 residual EDTA blood samples from pregnant Madagascan women were assessed. The nucleic acid extractions were subjected to in-house real-time PCRs specifically targeting S. mansoni complex, S. haematobium complex, and African Schistosoma spp. on genus level, while the EDTA plasma samples were analyzed using Schistosoma-specific IgG and IgM commercial ELISA and immunofluorescence assays. The analyses indicated an overall prevalence of schistosomiasis in Madagascan pregnant women of 40.4%, with only minor regional differences and differences between serology- and blood PCR-based surveillance. The S. mansoni specific real-time PCR showed superior sensitivity of 74% (specificity 80%) compared with the genus-specific real-time PCR (sensitivity 13%, specificity 100%) in blood. The laborious immunofluorescence (sensitivity IgM 49%, IgG 87%, specificity IgM 85%, IgG 96%) scored only slightly better than the automatable ELISA (sensitivity IgM 38%, IgG 88%, specificity IgM 78%, IgG 91%). Infections with S. mansoni were detected only. The high prevalence of schistosomiasis recorded here among pregnant women in Madagascar calls for actions in order to reduce the disease burden.

Suckling by Schistosoma mansoni-infected mothers restored IgG2a and TGF-β production, but not IL-6 and delayed-type hypersensitivity in IL-12/IL-23-deficient mice

INTRODUCTION

Suckling by schistosomotic mice improves anti-ovalbumin (OA) antibody production, while delayed-type hypersensitivity (DTH) remains unaffected. This property of milk from schistosomotic mice was investigated in IL-12/IL-23-deficient mice (IL-12p40KO).

METHODS

We compared anti-OA DTH, IgG2a and cytokines in wild-type and IL-12p40KO mice suckled by infected (SIM) or non-infected (CONTROL) mothers.

RESULTS

SIM mice showed similar intensity and eosinophils in the DTH, which was abolished in IL-12p40KO and IL-12p40KO-SIM mice. In IL-12p40KO-SIM, IgG2a and TGF-β levels were higher, but IL-6 levels were lower.

CONCLUSIONS

Milk from schistosomotic mothers may evoke IgG2a without eliciting DTH in IL-12/IL-23 deficiencies, by changing TGF-β/IL-6 levels.

Prevalence of schistosomiasis and its association with anemia among pregnant women: a systematic review and meta-analysis

BACKGROUND

Schistosomiasis is a highly prevalent parasitic disease that can lead to adverse maternal and perinatal outcomes. To our knowledge, there has been no systematic review and meta-analysis of schistosomiasis during pregnancy.

METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant published studies were searched in international databases (PubMed, Science Direct, Scopus, Web of Science, and Google Scholar), from their inception until May 31, 2020. The retrieved studies were assessed for quality using the Modified Newcastle-Ottawa Scale. OpenMeta Analyst software was used for the statistical analysis.

RESULTS

Thirty-two studies enrolling 21024 pregnant women were included in this meta-analysis. All 32 of these studies were conducted in Africa. Of these studies, 19, 11, and 2 investigated S. mansoni, S. haematobium, and combined S. mansoni and S. haematobium infections, respectively. The pooled prevalence estimate of schistosomiasis during pregnancy was 13.2% (95 CI 11.0-15.4). A random model was used because of high heterogeneity (Q = 99.14; P < 0.001). In subgroup analyses, the pooled prevalence estimate of S. haematobium was significantly higher than the pooled prevalence estimates of S. mansoni [22.5% (95% CI 1.6-43.5) vs 8.7% (95% CI 6.0-11.3, P = 0.016), respectively]. The results of meta-regression analyses showed a non-significant difference in the prevalence of schistosomiasis during pregnancy according to the study sample sizes and year of publication. Only six studies evaluated the association between schistosomiasis during pregnancy and anemia. Schistosomiasis was associated with anemia in these six studies (OR = 3.02, 95% = 1.25‒7.28, P = 0.014).

CONCLUSION

The present meta-analysis suggests that schistosomiasis during pregnancy is an existing health problem. This meta-analysis also highlights the lack of data on the determinants and outcomes of schistosomiasis during pregnancy. Preventive measures are needed and could be part of antenatal care in areas endemic with schistosomiasis.

miR-146a-5p improves the decidual cytokine microenvironment by regulating the toll-like receptor signaling pathway in unexplained spontaneous abortion

Spontaneous abortion (SA) is a common pregnancy failure, but the cause of numerous cases remains unexplained. Decidual immune cells (DICs)-mediated cytokine microenvironment is involved in pregnancy and regulated by many microRNAs, but whether microRNA-146a-5p (miR-146a) regulate the decidual cytokine microenvironment and the potential mechanisms in unexplained SA pathogenesis have rarely been reported. In this study, the levels of cytokines and miR-146a in healthy and unexplained SA deciduae were first investigated, and the correlation between them was analyzed. Then, the effect of miR-146a inhibitor on cytokines was assessed in healthy deciduae-derived DICs. Third, the downstream targets and related molecular mechanisms of miR-146a were analyzed by bioinformatics, and the levels of the predicted targets in deciduae were assessed, followed by the correlation analysis between the levels of miR-146a and the targets. Finally, the effect of miR-146a on the predicted targets and inflammatory cytokines was validated in unexplained SA deciduae-derived DICs. As a result, decreased miR-146a correlated with the cytokine disorder in unexplained SA deciduae, and inhibition of miR-146a promoted pro-inflammatory response in healthy deciduae-derived DICs. One hundred four target genes and related molecular mechanisms of miR-146a were predicted, among which the toll-like receptor (TLR) pathway might be associated with the decidual cytokine regulation. Upregulation of miR-146a inhibited the expression of the predicted molecules enriched in the TLR pathway and improved the cytokine disorder in unexplained SA deciduae-derived DICs. Collectively, miR-146a improves the decidual cytokine microenvironment by regulating the TLR pathway in unexplained SA, providing novel potential targets for further therapeutic research.

Subclinical in utero Zika virus infection is associated with interferon alpha sequelae and sex-specific molecular brain pathology in asymptomatic porcine offspring

Zika virus (ZIKV) infection during human pregnancy may lead to severe fetal pathology and debilitating impairments in offspring. However, the majority of infections are subclinical and not associated with evident birth defects. Potentially detrimental life-long health outcomes in asymptomatic offspring evoke high concerns. Thus, animal models addressing sequelae in offspring may provide valuable information. To induce subclinical infection, we inoculated selected porcine fetuses at the mid-stage of development. Inoculation resulted in trans-fetal virus spread and persistent infection in the placenta and fetal membranes for two months. Offspring did not show congenital Zika syndrome (e.g., microcephaly, brain calcifications, congenital clubfoot, arthrogryposis, seizures) or other visible birth defects. However, a month after birth, a portion of offspring exhibited excessive interferon alpha (IFN-α) levels in blood plasma in a regular environment. Most affected offspring also showed dramatic IFN-α shutdown during social stress providing the first evidence for the cumulative impact of prenatal ZIKV exposure and postnatal environmental insult. Other eleven cytokines tested before and after stress were not altered suggesting the specific IFN-α pathology. While brains from offspring did not have histopathology, lesions, and ZIKV, the whole genome expression analysis of the prefrontal cortex revealed profound sex-specific transcriptional changes that most probably was the result of subclinical in utero infection. RNA-seq analysis in the placenta persistently infected with ZIKV provided independent support for the sex-specific pattern of in utero-acquired transcriptional responses. Collectively, our results provide strong evidence that two hallmarks of fetal ZIKV infection, altered type I IFN response and molecular brain pathology can persist after birth in offspring in the absence of congenital Zika syndrome.

A number of studies showed that Zika virus (ZIKV) can cause severe abnormalities in fetuses, e.g., brain lesions, and subsequently life-long developmental and cognitive impairment in children. However, the majority of infections in pregnant women are subclinical and are not associated with developmental abnormalities in fetuses and newborns. It is known that disruptions to the in utero environment during fetal development can program increased risks for disease in adulthood. For this reason, children affected in utero even by mild ZIKV infection can appear deceptively healthy at birth but develop immune dysfunction and brain abnormalities during postnatal development. Here, we used the porcine model of subclinical fetal ZIKV infection to determine health sequelae in offspring which did not show apparent signs of the disease. We demonstrated that subclinical fetal infection was associated with abnormal immunological responses in apparently healthy offspring under normal environmental conditions and during social stress. We also showed silent sex-specific brain pathology as represented by altered gene expression. Our study provides new insights into potential outcomes of subclinical in utero ZIKV infection. It also emphasizes that further attempts to better understand silent pathology and develop alleviative interventions in ZIKV-affected offspring should take into account interactions of host factors, like sex, and environmental insults, like social stress.

Comparative study of excretory-secretory proteins released by Schistosoma mansoni-resistant, susceptible and naïve Biomphalaria glabrata

BACKGROUND

Schistosomiasis is a harmful neglected tropical disease caused by infection with Schistosoma spp., such as Schistosoma mansoni. Schistosoma must transition within a molluscan host to survive. Chemical analyses of schistosome-molluscan interactions indicate that host identification involves chemosensation, including naïve host preference. Proteomic technique advances enable sophisticated comparative analyses between infected and naïve snail host proteins. This study aimed to compare resistant, susceptible and naïve Biomphalaria glabrata snail-conditioned water (SCW) to identify potential attractants and deterrents.

METHODS

Behavioural bioassays were performed on S. mansoni miracidia to compare the effects of susceptible, F1 resistant and naïve B. glabrata SCW. The F1 resistant and susceptible B. glabrata SCW excretory-secretory proteins (ESPs) were fractionated using SDS-PAGE, identified with LC-MS/MS and compared to naïve snail ESPs. Protein-protein interaction (PPI) analyses based on published studies (including experiments, co-expression, text-mining and gene fusion) identified S. mansoni and B. glabrata protein interaction. Data are available via ProteomeXchange with identifier PXD015129.

RESULTS

A total of 291, 410 and 597 ESPs were detected in the susceptible, F1 resistant and naïve SCW, respectively. Less overlap in ESPs was identified between susceptible and naïve snails than F1 resistant and naïve snails. F1 resistant B. glabrata ESPs were predominately associated with anti-pathogen activity and detoxification, such as leukocyte elastase and peroxiredoxin. Susceptible B. glabrata several proteins correlated with immunity and anti-inflammation, such as glutathione S-transferase and zinc metalloproteinase, and S. mansoni sporocyst presence. PPI analyses found that uncharacterised S. mansoni protein Smp_142140.1 potentially interacts with numerous B. glabrata proteins.

CONCLUSIONS

This study identified ESPs released by F1 resistant, susceptible and naïve B. glabrata to explain S. mansoni miracidia interplay. Susceptible B. glabrata ESPs shed light on potential S. mansoni miracidia deterrents. Further targeted research on specific ESPs identified in this study could help inhibit B. glabrata and S. mansoni interactions and stop human schistosomiasis.

Maternal Schistosomiasis: Immunomodulatory Effects With Lasting Impact on Allergy and Vaccine Responses

Early exposure to immune stimuli, including maternal infection during the perinatal period, is increasingly recognized to affect immune predisposition during later life. This includes exposure to not only viral and bacterial infection but also parasitic helminths which remain widespread. Noted effects of helminth infection, including altered incidence of atopic inflammation and vaccine responsiveness, support further research into the impact these infections have for skewing immune responses. At the same time, despite a sea of recommendations, clear phenotypic and mechanistic understandings of how environmental perturbations in pregnancy and nursing modify immune predisposition and allergy in offspring remain unrefined. Schistosomes, as strong inducers of type 2 immunity embedded in a rich network of regulatory processes, possess strong abilities to shift inflammatory and allergic diseases in infected hosts, for example by generating feedback loops that impair T cell responses to heterologous antigens. Based on the current literature on schistosomiasis, we explore in this review how maternal schistosome infection could drive changes in immune system development of offspring and how this may lead to identifying factors involved in altering responses to vaccination as well as manifestations of immune disorders including allergy.

Maternal helminth infections and the shaping of offspring immunity

Helminth infections leave a long-lasting immunological footprint on their hosts. Clinical studies have provided first evidence that maternal helminth infections can result in an altered immune profile in their offspring which can potentially shape how they respond to conditions throughout life. This can relate to changes in offspring induction of immune responses against other diseases. However, whether these changes result in actual changes in offspring ability to control disease is unclear. Our understanding of which immune mechanisms are altered and how they are changed is limited. In this review, we highlight what we know from human and mouse studies about this important context of helminth exposure. Moreover, we discuss how mechanisms such as antibody transfer, antigen exposure, maternal cell uptake, chimerism and epigenetics are all likely to be functional contributors to the striking changes that are seen in offspring born or nursed by helminth exposed mothers.

Immune response to purified protein derivative in infants from helminth-sensitized mothers - A cases series

BACKGROUND

Maternal exposure to antibodies, cytokines or parasitic antigens during gestation may alter the degree of immune competence of offspring. Here we describe the production of cytokines and chemokines, and the ability to activation of the immune response in infants from mothers sensitized to helminths.

METHODS

It were selected five infants born to helminth-seropositive mothers but who were negative for current helminth infection. Whole blood was cultured without stimulus, with phytohemagglutinin mitogen (5 μg/ml, 24 h) or with purified protein derivative (PPD) (1 μg/ml, 24 h), and the supernatant was assessed for presence of Th1/Th2 cytokines (IFN-γ, TNF-α, IL-10, IL-5, IL-4 and IL-2) and chemokines (CXCL10, CCL2, CXCL9, CCL5 and CXCL8) by cytometric bead array.

RESULTS

All infants produced CCL5. Two infants demonstrated a mixed profile of Th1 (CXCL9) and Th2 (CCL2) chemokines in the presence of CXCL10, while one infant showed skewing towards Th2 without CXCL10 and two of them had been impaired immune response (children from sensitized to Schistosoma mansoni mothers).

CONCLUSION

Infants with Th1 and Th2 profile chemokines demonstrated a good response to vaccination, indicated by CXCL10 levels, but not infants predominantly Th2-skewed profile. These results highlight that children from mothers sensitized to S. mansoni may lead to ineffective immune response to PPD, while mothers sensitized to Ascaris lumbricoides showed no such impairment.