A wild boar cathelicidin peptide derivative inhibits severe acute respiratory syndrome coronavirus-2 and its drifted variants.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a clear threat to humanity. It has infected over 200 million and killed 4 million people worldwide, and infections continue with no end in sight. To control the pandemic, multiple effective vaccines have been developed, and global vaccinations are in progress. However, the virus continues to mutate. Even when full vaccine coverage is achieved, vaccine-resistant mutants will likely emerge, thus requiring new annual vaccines against drifted variants analogous to influenza. A complimentary solution to this problem could be developing antiviral drugs that inhibit SARS CoV-2 and its drifted variants. Host defense peptides represent a potential source for such an antiviral as they possess broad antimicrobial activity and significant diversity across species. We screened the cathelicidin family of peptides from 16 different species for antiviral activity and identified a wild boar peptide derivative that inhibits SARS CoV-2. This peptide, which we named Yongshi and means warrior in Mandarin, acts as a viral entry inhibitor. Following the binding of SARS-CoV-2 to its receptor, the spike protein is cleaved, and heptad repeats 1 and 2 multimerize to form the fusion complex that enables the virion to enter the cell. A deep learning-based protein sequence comparison algorithm and molecular modeling suggest that Yongshi acts as a mimetic to the heptad repeats of the virus, thereby disrupting the fusion process. Experimental data confirm the binding of Yongshi to the heptad repeat 1 with a fourfold higher affinity than heptad repeat 2 of SARS-CoV-2. Yongshi also binds to the heptad repeat 1 of SARS-CoV-1 and MERS-CoV. Interestingly, it inhibits all drifted variants of SARS CoV-2 that we tested, including the alpha, beta, gamma, delta, kappa and omicron variants.

Relatlimab-nivolumab: A practical overview for dermatologists.

BACKGROUND: Relatlimab is a human anti-lymphocyte activation gene 3 protein antibody approved for the treatment of metastatic or unresectable melanoma in combination with nivolumab, an existing programmed cell death protein 1 inhibitor. OBJECTIVE: In this article, we review the clinical literature on the efficacy and therapeutic use of the immune checkpoint inhibitor relatlimab in combination with nivolumab for metastatic melanoma. METHODS: We provide an overview of the mechanism of action, clinical efficacy, and safety profile of relatlimab-nivolumab through a review of recent publications on this emerging therapeutic combination. Ongoing clinical trials studying the use of relatlimab and associated areas of active investigation are also highlighted. CONCLUSION: This review strives to inform practicing dermatologists on the use of relatlimab-nivolumab as an approved first-line dual checkpoint inhibitor for metastatic melanoma in appropriate clinical cases.