Occurrence, Biological and Enzymatic Activities of Agaricomycetes from the Brazilian Amazon - A Systematic Review.

Agaricomycetes are highlighted for producing a variety of compounds and enzymes with nutritional and medicinal properties. However, the knowledge of the diversity of this group of fungi is still insufficient, as well as their biological and enzymatic activities. Thus, the objective of this work is to describe the occurrence, biological and enzymatic activities of Agaricomycetes from the Brazilian Amazon. The present study is a systematic review with the literature search done in the following databases: Scielo, Google Scholar, PubMed and ScienceDirect. The descriptors used were Basidiomycota, Agaricomycetes, mushroom, antimicrobial activity, antitumor activity, antioxidant activity, anti-inflammatory activity, immunomodulator, enzymatic activity, and Brazilian Amazon. We used as inclusion criteria articles in Portuguese and English, published between 2010 and 2021 and that had the full text available and presented relevance to the exposed topic, and as exclusion criteria, works not done in the Brazilian Amazon, duplicate articles in the databases search or outside the topic under study. A total of 40 articles, published between 2010 and 2021, were selected for analysis. 230 species of Agaricomycetes fungi were described for the Brazilian Amazon, with the most frequent orders being Polyporales (52.60%), Agaricales (14.35%), and Hymenochaetales (13.91%). Six studies were found on antimicrobial activity for promising Agaricomycete fungi against the bacteria Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and the fungi Candida albicans, C. parapsilosis and C. tropicalis. For the antioxidant activity, a study described the species Lentinus citrinus with high amounts of antioxidant compounds. For enzymatic activity, five studies reported Agaricomycete fungi producing protease, cellulase, amylase, pectinase, laccase, and xylanase enzymes. This review shows the scarcity of studies on the description and technological potential of Agaricomycetes from the Brazilian Amazon, highlighting the need to encourage the study of this group of organisms.

Durability and cross-reactivity of SARS-CoV-2 mRNA vaccine in adolescent children

Emergent SARS-CoV-2 variants and waning humoral immunity in vaccinated individuals have resulted in increased infections and hospitalizations. Children are not spared from infection nor complications of COVID-19, and the recent recommendation for boosters in individuals ages 12 years or older calls for broader understanding of the adolescent immune profile after mRNA vaccination. We tested the durability and cross-reactivity of anti-SARS-CoV-2 serologic responses over a six-month time course in vaccinated adolescents against the SARS-CoV-2 wild type and Omicron antigens. Serum from 77 adolescents showed that anti-Spike antibodies wane significantly over 6 months. After completion of a two-vaccine series, cross-reactivity against Omicron-specific receptor-binding domain (RBD) was seen. Evidence of waning mRNA-induced vaccine immunity underscores vulnerabilities in long-term pediatric protection against SARS-CoV-2 infection, while cross-reactivity highlights the additional benefits of vaccination. Characterization of adolescent immune signatures post-vaccination will inform guidance on vaccine platforms and timelines, and ultimately optimize immunoprotection of children.

Sexually dimorphic placental responses to maternal SARS-CoV-2 infection

There is a persistent male bias in the prevalence and severity of COVID-19 disease. Underlying mechanisms accounting for this sex difference remain incompletely understood. Interferon responses have been implicated as a modulator of disease in adults, and play a key role in the placental anti-viral response. Moreover, the interferon response has been shown to alter Fc-receptor expression, and therefore may impact placental antibody transfer. Here we examined the intersection of viral-induced placental interferon responses, maternal-fetal antibody transfer, and fetal sex. Placental interferon stimulated genes (ISGs), Fc-receptor expression, and SARS-CoV-2 antibody transfer were interrogated in 68 pregnancies. Sexually dimorphic placental expression of ISGs, interleukin-10, and Fc receptors was observed following maternal SARS-CoV-2 infection, with upregulation in males. Reduced maternal SARS-CoV-2-specific antibody titers and impaired placental antibody transfer were noted in pregnancies with a male fetus. These results demonstrate fetal sex-specific maternal and placental adaptive and innate immune responses to SARS-CoV-2.