Prolonged viral shedding in an immunocompromised Korean patient infected with hMPXV, sub-lineage B.1.3, with acquired drug resistant mutations during tecovirimat treatment.

Following the worldwide surge in mpox (monkeypox) in 2022, cases have persisted in Asia, including South Korea, and sexual contact is presumed as the predominant mode of transmission, with a discernible surge in prevalence among immunocompromised patients. Drugs such as tecovirimat can result in drug-resistant mutations, presenting obstacles to treatment. This study aimed to ascertain the presence of tecovirimat-related resistant mutations through genomic analysis of the monkeypox virus isolated from a reported case involving prolonged viral shedding in South Korea. Here, tecovirimat-resistant mutations, previously identified in the B.1 clade, were observed in the B.1.3 clade, predominant in South Korea. These mutations exhibited diverse patterns across different samples from the same patient and reflected the varied distribution of viral subpopulations in different anatomical regions. The A290V and A288P mutant strains we isolated hold promise for elucidating these mechanisms, enabling a comprehensive analysis of viral pathogenesis, replication strategies, and host interactions. Our findings imply that acquired drug-resistant mutations, may present a challenge to individual patient treatment. Moreover, they have the potential to give rise to transmitted drug-resistant mutations, thereby imposing a burden on the public health system. Consequently, the meticulous genomic surveillance among immunocompromised patients, conducted in this research, assumes paramount importance.

The Role of N-Glycosylation in the Intracellular Trafficking and Functionality of Neuronal Growth Regulator 1.

Neuronal growth regulator 1 (NEGR1) is a brain-enriched membrane protein that is involved in neural cell communication and synapse formation. Accumulating evidence indicates that NEGR1 is a generic risk factor for various psychiatric diseases including autism and depression. Endoglycosidase digestion of single NEGR1 mutants revealed that the wild type NEGR1 has six putative N-glycosylation sites partly organized in a Golgi-dependent manner. To understand the role of each putative N-glycan residue, we generated a series of multi-site mutants (2MT-6MT) with additive mutations. Cell surface staining and biotinylation revealed that NEGR1 mutants 1MT to 4MT were localized on the cell surface at different levels, whereas 5MT and 6MT were retained in the endoplasmic reticulum to form highly stable multimer complexes. This indicated 5MT and 6MT are less likely to fold correctly. Furthermore, the removal of two N-terminal sites N75 and N155 was sufficient to completely abrogate membrane targeting. An in vivo binding assay using the soluble NEGR1 protein demonstrated that glycans N286, N294 and N307 on the C-terminal immunoglobulin-like domain play important roles in homophilic interactions. Taken together, these results suggest that the N-glycan moieties of NEGR1 are closely involved in the folding, trafficking, and homodimer formation of NEGR1 protein in a site-specific manner.