Project description:The outbreak-causing monkeypox virus of 2022 (2022 MPXV) is classified as a clade IIb strain and phylogenetically distinct from prior endemic MPXV strains (clades I or IIa), suggesting that its virological properties may also differ. Here, we used human keratinocytes and induced pluripotent stem cell-derived colon organoids to examine the efficiency of viral growth in these cells and the MPXV infection-mediated host responses. MPXV replication was much more productive in keratinocytes than in colon organoids. We observed that MPXV infections, regardless of strain, caused cellular dysfunction and mitochondrial damage in keratinocytes. Notably, a significant increase in the expression of hypoxia-related genes was observed specifically in 2022 MPXV-infected keratinocytes. Our comparison of virological features between 2022 MPXV and prior endemic MPXV strains revealed signaling pathways potentially involved with the cellular damages caused by MPXV infections and highlights host vulnerabilities that could be utilized as protective therapeutic strategies against human mpox in the future.
Project description:The soaring global monkeypox cases lead to a surge in demand for monkeypox vaccine, which far exceeds the supply. mRNA vaccine has achieved great success in prevention of coronavirus disease and holds promise against diverse pathogens. In this study, we generate a polyvalent lipid nanoparticle (LNP) mRNA vaccine candidate for monkeypox virus (MPXV) and evaluate its immunogenicity in animal models. This polyvalent MPXV mRNA vaccine candidate, MPXVac-097, encodes five 2022 MPXV targets that are important surface antigens. Three-dose (prime-boost-booster) MPXVac-097 vaccination elicits strong antibody response to A35R and E8L antigens, moderate response to M1R, but not B6R or A29, highlighting the differences in immunogenicity. Bulk T cell receptor (TCR) sequencing reveals preferential usage of VJ combinations and clonal expansion of peripheral T cells after MPXVac-097 vaccination. These data demonstrate initial feasibility of developing MPXV mRNA vaccine and pave the way for its future optimization.
Project description:Monkeypox virus (MPXV) infection-associated intestinal manifestations including diarrhea and proctitis have been frequently reported during mpox outbreaks. The clade IIb MPXV strain has caused the 2022-2023 global outbreak, whereas the Ia and Ib strains are causing the concurrent outbreaks in Africa. Here, we found clinical evidence that MPXV can directly infect human intestine to induce lesions. Intriguingly, primary organoids cultured from human ileum and rectum support productive infections of MPXV clade IIb, Ia and Ib strains. Upon differentiation, we found that enterocytes and goblet cells but not enteroendocrine cells are capable of supporting viral replication. Given that primary intestinal organoids can be rapidly expanded in large scale, we were able to screen a broad-spectrum antiviral drug library. We identified 12 leading candidates of safe-in-human agents including clinically used drugs such as clofarabine. We extensively validated the anti-MPXV activity of clofarabine in human intestinal and skin organoids, and consistently demonstrated the potent antiviral activity against clade Ia, Ib and IIb strains. These findings are important for better understanding the clinical manifestations of mpox. Primary intestinal organoids-based infection models and the established antiviral drug discovery pipeline bear major implications in responding to the current mpox global health emergency, and sustaining epidemic poxvirus preparedness.