RESUMEN
The global outbreak of the mpox virus (MPXV) in 2022 highlights the urgent need for safer and more accessible new-generation vaccines. Here, we used a structure-guided multi-antigen fusion strategy to design a 'two-in-one' immunogen based on the single-chain dimeric MPXV extracellular enveloped virus antigen A35 bivalently fused with the intracellular mature virus antigen M1, called DAM. DAM preserved the natural epitope configuration of both components and showed stronger A35-specific and M1-specific antibody responses and in vivo protective efficacy against vaccinia virus (VACV) compared to co-immunization strategies. The MPXV-specific neutralizing antibodies elicited by DAM were 28 times higher than those induced by live VACV vaccine. Aluminum-adjuvanted DAM vaccines protected mice from a lethal VACV challenge with a safety profile, and pilot-scale production confirmed the high yield and purity of DAM. Thus, our study provides innovative insights and an immunogen candidate for the development of alternative vaccines against MPXV and other orthopoxviruses.
Asunto(s)
Monkeypox virus , Vacunas , Animales , Ratones , Proteínas del Envoltorio Viral , Anticuerpos Antivirales , Virus Vaccinia , Antígenos Virales , InmunidadRESUMEN
Zygotic genome activation (ZGA) activates the quiescent genome to enable the maternal-to-zygotic transition1,2. However, the identity of transcription factors that underlie mammalian ZGA in vivo remains elusive. Here we show that OBOX, a PRD-like homeobox domain transcription factor family (OBOX1-OBOX8)3-5, are key regulators of mouse ZGA. Mice deficient for maternally transcribed Obox1/2/5/7 and zygotically expressed Obox3/4 had a two-cell to four-cell arrest, accompanied by impaired ZGA. The Obox knockout defects could be rescued by restoring either maternal and zygotic OBOX, which suggests that maternal and zygotic OBOX redundantly support embryonic development. Chromatin-binding analysis showed that Obox knockout preferentially affected OBOX-binding targets. Mechanistically, OBOX facilitated the 'preconfiguration' of RNA polymerase II, as the polymerase relocated from the initial one-cell binding targets to ZGA gene promoters and distal enhancers. Impaired polymerase II preconfiguration in Obox mutants was accompanied by defective ZGA and chromatin accessibility transition, as well as aberrant activation of one-cell polymerase II targets. Finally, ectopic expression of OBOX activated ZGA genes and MERVL repeats in mouse embryonic stem cells. These data thus demonstrate that OBOX regulates mouse ZGA and early embryogenesis.
Asunto(s)
Desarrollo Embrionario , Regulación del Desarrollo de la Expresión Génica , Genoma , Proteínas de Homeodominio , Factores de Transcripción , Cigoto , Animales , Ratones , Cromatina/genética , Cromatina/metabolismo , Desarrollo Embrionario/genética , Elementos de Facilitación Genéticos/genética , Genoma/genética , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Células Madre Embrionarias de Ratones/metabolismo , Mutación , Regiones Promotoras Genéticas/genética , ARN Polimerasa II/metabolismo , Factores de Transcripción/deficiencia , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Cigoto/metabolismoRESUMEN
BACKGROUND: Mpox has spread to many countries around the world. While the existing live attenuated mpox vaccines are effective, advances in 21st century technologies now enable the development of vaccines with more specific antigens, clearer mechanisms, and more controllable side effects. METHODS: We systematically evaluated the immunogenicity and protective efficacy of the A35R, M1R and B6R antigens of the mpox virus (MPXV). With these findings, we designed three single-chain trivalent mRNA vaccines (AMAB-wt, AMAB-C140S and AMB-C140S) by integrating the soluble regions of these antigens into single mRNA-encoded polypeptides based on their protein structures. Then, the immunogenicity and protective efficacy of these single-chain mRNA vaccines were evaluated in mice models against both VACV and MPXV. FINDINGS: The three single-chain vaccines elicited neutralising antibodies that effectively neutralised both VACV and MPXV. The single-chain vaccines or cocktail vaccine containing mRNAs encoding soluble antigen (sA35R + sM1R + sB6R) exhibited 100% or 80% protection against a lethal dose of VACV challenge, while the cocktail of full-length antigens (A35 + M1 + B6) and the live attenuated vaccine, VACV Tian Tan (VACV-VTT), completely failed to protect mice. Moreover, the single-chain vaccines significantly reduced viral load in the lungs and ovaries of MPXV-challenged mice. INTERPRETATION: Compared with the cocktail vaccines, our single-chain designs demonstrated similar or superior immunogenicity and protective efficacy. Importantly, the simplicity of the single-chain vaccines enhances both the controllability and accessibility of mpox vaccines. We believe these single-chain vaccines qualify as the next-generation mpox vaccines. FUNDING: National Natural Science Foundation of China and Youth Innovation Promotion Association of the CAS.