Pre-pandemic antibodies screening against SARS-CoV-2 and virus detection among children diagnosed with eruptive fevers.

OBJECTIVES: This study aims to assess the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies against the spike (S) and nucleocapsid (NP) proteins, as well as neutralizing antibodies against the receptor-binding domain (RBD). Additionally, it aims to detect viral RNA of SARS-CoV-2 in pre-pandemic archival pediatric specimens collected before the announcement of the COVID-19 pandemic spread on March 20th, 2020, in Morocco. The objective is to investigate the existence of pre-pandemic immunity to SARS-CoV-2. METHODS: We conducted a cross-sectional study, to analyze IgG antibody levels in a cohort of 106 pre-pandemic pediatric participants. Using an indirect enzyme-linked immunosorbent assay (ELISA), we measured the IgG levels against the S and NP proteins of SARS-CoV-2. Additionally, we staged a competitive ELISA assay to evaluate the neutralizing capability of these antibodies. We used reverse transcription polymerase chain reaction (rRT-PCR) to detect viral NP and ORF1ab genes of SARS-CoV-2 in oropharyngeal swabs. Moreover, we conducted on the same specimens a multiplexed RT-PCR to detect RNA of the most common 27 pathogens involved in lower respiratory tract infections. RESULTS: Among the 106 serum samples, 13% (nn = =14) tested positive for SARS-CoV-2 IgG antibodies using ELISA. Temporal analysis indicated varying IgG positivity levels across 2019. Neutralizing antibodies were found in 21% of the 28 samples analyzed, including two with high inhibition rates (93%). The SARS-CoV-2 RNA was detected using rRT-PCR in 14 samples. None of the samples tested positive for the other 27 pathogens associated with lower respiratory tract infections, using multiplexed RT-PCR. CONCLUSION: Our study addresses the possibility, that COVID-19 infections occurred in Morocco before the recognized outbreak. On the other hand, some of the cases might reflect cross-reactivity with other coronaviruses or be influenced by previous viral exposures or vaccinations. Understanding these factors is crucial to comprehending pediatric immune responses to newly emerging infectious diseases.

Plant-Based HSP90 Inhibitors in Breast Cancer Models: A Systematic Review.

Breast cancer, the most invasive cancer in women globally, necessitates novel treatments due to prevailing limitations of therapeutics. Search of news anticancer targets is more necessary than ever to tackle this pathology. Heat-Shock Protein 90 (HSP90), a chaperone protein, is implicated in breast cancer pathogenesis, rendering it an appealing target. Looking for alternative approach such as Plant-based compounds and natural HSP90 inhibitors offer promising prospects for innovative therapeutic strategies. This study aims to identify plant-based compounds with anticancer effects on breast cancer models and elucidate their mechanism of action in inhibiting the HSP90 protein. A systematic review was conducted and completed in January 2024 and included in vitro, in vivo, and in silico studies that investigated the effectiveness of plant-based HSP90 inhibitors tested on breast cancer models. Eleven studies were included in the review. Six plants and 24 compounds from six different classes were identified and proved to be effective against HSP90 in breast cancer models. The studied plant extracts showed a dose- and time-dependent decrease in cell viability. Variable IC50 values showed antiproliferative effects, with the plant Tubocapsicum anomalum demonstrating the lowest value. Withanolides was the most studied class. Fennel, Trianthema portulacastrum, and Spatholobus suberectus extracts were shown to inhibit tumor growth and angiogenesis and modulate HSP90 expression as well as its cochaperone interactions in breast cancer mouse models. The identified plant extracts and compounds were proven effective against HSP90 in breast cancer models, and this inhibition showed promising effects on breast cancer biology. Collectively, these results urge the need of further studies to better understand the mechanism of action of HSP90 inhibitors using comparable methods for preclinical observations.