Multiomics Approach Reveals Serum Biomarker Candidates for Congenital Zika Syndrome.

The Zika virus (ZIKV) can be vertically transmitted, causing congenital Zika syndrome (CZS) in fetuses. ZIKV infection in early gestational trimesters increases the chances of developing CZS. This syndrome involves several pathologies with a complex diagnosis. In this work, we aim to identify biological processes and molecular pathways related to CZS and propose a series of putative protein and metabolite biomarkers for CZS prognosis in early pregnancy trimesters. We analyzed serum samples of healthy pregnant women and ZIKV-infected pregnant women bearing nonmicrocephalic and microcephalic fetuses. A total of 1090 proteins and 512 metabolites were identified by bottom-up proteomics and untargeted metabolomics, respectively. Univariate and multivariate statistical approaches were applied to find CZS differentially abundant proteins (DAP) and metabolites (DAM). Enrichment analysis (i.e., biological processes and molecular pathways) of the DAP and the DAM allowed us to identify the ECM organization and proteoglycans, amino acid metabolism, and arachidonic acid metabolism as CZS signatures. Five proteins and four metabolites were selected as CZS biomarker candidates. Serum multiomics analysis led us to propose nine putative biomarkers for CZS prognosis with high sensitivity and specificity.

Amniotic fluid metabolomics identifies impairment of glycerophospholipid and amino acid metabolism during congenital Zika syndrome development.

PURPOSE: Our main goal is to identify the alterations in the amniotic fluid (AF) metabolome in Zika virus (ZIKV)-infected patients and their relation to congenital Zika syndrome (CZS) progression. EXPERIMENTAL DESIGN: We applied an untargeted metabolomics strategy to analyze seven AF of pregnant women: healthy women and ZIKV-infected women bearing non-microcephalic and microcephalic fetuses. RESULTS: Infected patients were characterized by glycerophospholipid metabolism impairment, which is accentuated in microcephalic phenotypes. Glycerophospholipid decreased concentration in AF can be a consequence of intracellular transport of lipids to the placental or fetal tissues under development. The increased intracellular concentration of lipids can lead to mitochondrial dysfunction and neurodegeneration caused by lipid droplet accumulation. Furthermore, the dysregulation of amino acid metabolism was a molecular fingerprint of microcephalic phenotypes, specifically serine, and proline metabolisms. Both amino acid deficiencies were related to neurodegenerative disorders, intrauterine growth retardation, and placental abnormalities. CONCLUSIONS AND CLINICAL RELEVANCE: This study enhances our understanding of the development of CZS pathology and sheds light on dysregulated pathways that could be relevant for future studies.

Conformational stability of SARS-CoV-2 glycoprotein spike variants.

The severe acute respiratory syndrome spread worldwide, causing a pandemic. SARS-CoV-2 mutations have arisen in the spike, a glycoprotein at the viral envelope and an antigenic candidate for vaccines against COVID-19. Here, we present comparative data of the glycosylated full-length ancestral and D614G spike together with three other transmissible strains classified by the World Health Organization as variants of concern: beta, gamma, and delta. By showing that D614G has less hydrophobic surface exposure and trimer persistence, we place D614G with features that support a model of temporary fitness advantage for virus spillover. Furthermore, during the SARS-CoV-2 adaptation, the spike accumulates alterations leading to less structural stability for some variants. The decreased trimer stability of the ancestral and gamma and the presence of D614G uncoupled conformations mean higher ACE-2 affinities compared to the beta and delta strains. Mapping the energetics and flexibility of variants is necessary to improve vaccine development.

The oldest unvaccinated Covid-19 survivors in South America.

BACKGROUND: Although older adults are at a high risk of severe or critical Covid-19, there are many cases of unvaccinated centenarians who had a silent infection or recovered from mild or moderate Covid-19. We studied three Brazilian supercentenarians, older than 110 years, who survived Covid-19 in 2020 before being vaccinated. RESULTS: Despite their advanced age, humoral immune response analysis showed that these individuals displayed robust levels of IgG and neutralizing antibodies (NAbs) against SARS-CoV-2. Enrichment of plasma proteins and metabolites related to innate immune response and host defense was also observed. None presented autoantibodies (auto-Abs) to type I interferon (IFN). Furthermore, these supercentenarians do not carry rare variants in genes underlying the known inborn errors of immunity, including particular inborn errors of type I IFN. CONCLUSION: These observations suggest that their Covid-19 resilience might be a combination of their genetic background and their innate and adaptive immunity.

Proteomics of ZIKV infected amniotic fluids of microcephalic fetuses reveals extracellular matrix and immune system dysregulation.

During pregnancy, the vertical transmission of the Zika virus (ZIKV) can cause some disorders in the fetus, called Congenital Zika Syndrome (CZS). Several efforts have been made to understand the molecular mechanism of the CZS. However, the study of CZS pathogenesis through infected human samples is scarce. Therefore, the main goal of this study is to identify and understand the biological processes affected by CZS development. We analyzed by a shotgun proteomic approach the amniotic fluid of pregnant women infected with Zika carrying microcephalic (MC+ ) or non-microcephalic (Z+ ) fetuses compared to Zika negative controls (CTR). Several groups of extracellular matrix (ECM) proteins were dysregulated in the Z+ and MC+ patients, triggering an opposite dysregulation. The down-regulation of the ECM proteins in the MC+ groups can be another factor that contributes to CZS. On the contrary, the Z+ group could be developing a neuroprotective response through ECM proteins up-regulation. The neutrophil degranulation process was disrupted in the Z+ and MC+ groups, where the MC+ groups showed a complex dysregulation. These results suggest that the microcephalic phenotypes are modulated by a down-regulation of the ECM and the impairment of the innate immune system processes.

Proteomic profiles of Zika virus-infected placentas bearing fetuses with microcephaly.

PURPOSE: Zika virus (ZIKV) transmission to the fetus during pregnancy could enable a collection of severe fetal malformations like microcephaly (MC), termed Congenital Zika Syndrome (CZS). The mechanisms involved in ZIKV transplacental transmission are not fully understood. EXPERIMENTAL DESIGN: Here we aim to identify in placental tissues the deregulated proteins associated with ZIKV-induced MC using label-free proteomics. RESULTS: We found proteins associated with DNA damage and gene expression inhibition up-regulated in infected placentas with no MC fetuses (Z+) compared to the control group (Ctr). Actin filament organization and the immune response were also found deregulated in the Z+ group. In ZIKV-positive placentas bearing fetuses with MC (MC+) was detected an increase in T cell activation, indicating an elevated immune response. A comparison between MC+ and Z+ groups showed a higher abundance of proteins related to endocytosis and autophagy in MC+, suggesting a higher transcytosis of vesicles with ZIKV particles across the maternal-fetal interface. CONCLUSIONS AND CLINICAL RELEVANCE: Our results suggest that higher expression of integrins in MC+ might be associated with high internalization of the virus since these proteins are known as virus receptors. Similarly, an increased immune response in the placenta and higher infiltration of the virus to the fetus could contribute to the neurological malformation of the CZS.