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Viruses Nov 2020Monkeypox is a zoonotic disease caused by monkeypox virus (MPXV), which is a member of orthopoxvirus genus. The reemergence of MPXV in 2017 (at Bayelsa state) after 39... (Review)
Review
Monkeypox is a zoonotic disease caused by monkeypox virus (MPXV), which is a member of orthopoxvirus genus. The reemergence of MPXV in 2017 (at Bayelsa state) after 39 years of no reported case in Nigeria, and the export of travelers' monkeypox (MPX) from Nigeria to other parts of the world, in 2018 and 2019, respectively, have raised concern that MPXV may have emerged to occupy the ecological and immunological niche vacated by smallpox virus. This review X-rays the current state of knowledge pertaining the infection biology, epidemiology, and evolution of MPXV in Nigeria and worldwide, especially with regard to the human, cellular, and viral factors that modulate the virus transmission dynamics, infection, and its maintenance in nature. This paper also elucidates the role of recombination, gene loss and gene gain in MPXV evolution, chronicles the role of signaling in MPXV infection, and reviews the current therapeutic options available for the treatment and prevention of MPX. Additionally, genome-wide phylogenetic analysis was undertaken, and we show that MPXV isolates from recent 2017 outbreak in Nigeria were monophyletic with the isolate exported to Israel from Nigeria but do not share the most recent common ancestor with isolates obtained from earlier outbreaks, in 1971 and 1978, respectively. Finally, the review highlighted gaps in knowledge particularly the non-identification of a definitive reservoir host animal for MPXV and proposed future research endeavors to address the unresolved questions.
Topics: Animals; DNA, Viral; Evolution, Molecular; Humans; Mice; Mpox (monkeypox); Monkeypox virus; Nigeria; Phylogeny; Recombination, Genetic; Viral Zoonoses
PubMed: 33167496
DOI: 10.3390/v12111257 -
Nature Reviews. Immunology Oct 2022Monkeypox virus (MPXV), which causes disease in humans, has for many years been restricted to the African continent, with only a handful of sporadic cases in other parts... (Review)
Review
Monkeypox virus (MPXV), which causes disease in humans, has for many years been restricted to the African continent, with only a handful of sporadic cases in other parts of the world. However, unprecedented outbreaks of monkeypox in non-endemic regions have recently taken the world by surprise. In less than 4 months, the number of detected MPXV infections has soared to more than 48,000 cases, recording a total of 13 deaths. In this Review, we discuss the clinical, epidemiological and immunological features of MPXV infections. We also highlight important research questions and new opportunities to tackle the ongoing monkeypox outbreak.
Topics: Humans; Mpox (monkeypox); Monkeypox virus
PubMed: 36064780
DOI: 10.1038/s41577-022-00775-4 -
Journal of Medical Virology Jan 2023Mpox is a zoonotic disease caused by monkeypox virus (MPXV) from the Orthopoxvirus genus. Unprecedented transmission events have led to more than 70 000 cases reported... (Review)
Review
Mpox is a zoonotic disease caused by monkeypox virus (MPXV) from the Orthopoxvirus genus. Unprecedented transmission events have led to more than 70 000 cases reported worldwide by October 2022. The change in mpox epidemiology has raised concerns of its ability to establish endemicity beyond its traditional geographical locations. In this review, we discuss the current understanding of mpox virology and viral dynamics that are relevant to mpox diagnostics. A synopsis of the traditional and emerging laboratory technologies useful for MPXV detection and in guiding "elimination" strategies is outlined in this review. Importantly, development in MPXV genomics has rapidly advanced our understanding of the role of viral evolution and adaptation in the current outbreak.
Topics: Animals; Humans; Mpox (monkeypox); Monkeypox virus; Zoonoses; Orthopoxvirus; Disease Outbreaks
PubMed: 36571266
DOI: 10.1002/jmv.28429 -
Actas Dermo-sifiliograficas Jan 2023
Topics: Humans; Monkeypox virus; Mpox (monkeypox)
PubMed: 35780819
DOI: 10.1016/j.ad.2022.06.014 -
Cell Host & Microbe Jun 2023Mpox represents a persistent health concern with varying disease severity. Reinfections with mpox virus (MPXV) are rare, possibly indicating effective memory responses...
Mpox represents a persistent health concern with varying disease severity. Reinfections with mpox virus (MPXV) are rare, possibly indicating effective memory responses to MPXV or related poxviruses, notably vaccinia virus (VACV) from smallpox vaccination. We assessed cross-reactive and virus-specific CD4 and CD8 T cells in healthy individuals and mpox convalescent donors. Cross-reactive T cells were most frequently observed in healthy donors over 45 years. Notably, long-lived memory CD8 T cells targeting conserved VACV/MPXV epitopes were identified in older individuals more than four decades after VACV exposure and exhibited stem-like characteristics, defined by T cell factor-1 (TCF-1) expression. In mpox convalescent donors, MPXV-reactive CD4 and CD8 T cells were more prevalent than in controls, demonstrating enhanced functionality and skewing toward effector phenotypes, which correlated with milder disease. Collectively, we report robust effector memory MPXV-specific T cell responses in mild mpox and long-lived TCF-1 VACV/MPXV-specific CD8 T cells decades after smallpox vaccination.
Topics: Humans; CD8-Positive T-Lymphocytes; Mpox (monkeypox); Smallpox; Vaccinia virus; Poxviridae
PubMed: 37236191
DOI: 10.1016/j.chom.2023.04.015 -
Nature Communications Jan 2023The advantage of oncolytic viruses (OV) in cancer therapy is their dual effect of directly killing tumours while prompting anti-tumour immune response. Oncolytic...
The advantage of oncolytic viruses (OV) in cancer therapy is their dual effect of directly killing tumours while prompting anti-tumour immune response. Oncolytic parapoxvirus ovis (ORFV) and other OVs are thought to induce apoptosis, but apoptosis, being the immunogenically inert compared to other types of cell death, does not explain the highly inflamed microenvironment in OV-challenged tumors. Here we show that ORFV and its recombinant therapeutic derivatives are able to trigger tumor cell pyroptosis via Gasdermin E (GSDME). This effect is especially prominent in GSDME-low tumor cells, in which ORFV-challenge pre-stabilizes GSDME by decreasing its ubiquitination and subsequently initiates pyroptosis. Consistently, GSDME depletion reduces the proportion of intratumoral cytotoxic T lymphocytes, pyroptotic cell death and the success of tumor ORFV virotherapy. In vivo, the OV preferentially accumulates in the tumour upon systemic delivery and elicits pyroptotic tumor killing. Consequentially, ORFV sensitizes immunologically 'cold' tumors to checkpoint blockade. This study thus highlights the critical role of GSDME-mediated pyroptosis in oncolytic ORFV-based antitumor immunity and identifies combinatorial cancer therapy strategies.
Topics: Humans; Gasdermins; Neoplasms; Oncolytic Virotherapy; Oncolytic Viruses; Parapoxvirus; Pyroptosis; Tumor Microenvironment
PubMed: 36641456
DOI: 10.1038/s41467-023-35917-2 -
Cell Host & Microbe Dec 2022The monkeypox virus (MPXV) outbreak confirmed in May 2022 in non-endemic countries is raising concern about the pandemic potential of novel orthopoxviruses. Little is...
The monkeypox virus (MPXV) outbreak confirmed in May 2022 in non-endemic countries is raising concern about the pandemic potential of novel orthopoxviruses. Little is known regarding MPXV immunity in the context of MPXV infection or vaccination with vaccinia-based vaccines (VACV). As with vaccinia, T cells are likely to provide an important contribution to overall immunity to MPXV. Here, we leveraged the epitope information available in the Immune Epitope Database (IEDB) on VACV to predict potential MPXV targets recognized by CD4 and CD8 T cell responses. We found a high degree of conservation between VACV epitopes and MPXV and defined T cell immunodominant targets. These analyses enabled the design of peptide pools able to experimentally detect VACV-specific T cell responses and MPXV cross-reactive T cells in a cohort of vaccinated individuals. Our findings will facilitate the monitoring of cellular immunity following MPXV infection and vaccination.
Topics: Humans; Vaccinia virus; Monkeypox virus; Vaccinia; Mpox (monkeypox); Epitopes
PubMed: 36463861
DOI: 10.1016/j.chom.2022.11.003 -
Signal Transduction and Targeted Therapy Apr 2023Monkeypox has been declared a public health emergency by the World Health Organization. There is an urgent need for efficient and safe vaccines against the monkeypox...
Monkeypox has been declared a public health emergency by the World Health Organization. There is an urgent need for efficient and safe vaccines against the monkeypox virus (MPXV) in response to the rapidly spreading monkeypox epidemic. In the age of COVID-19, mRNA vaccines have been highly successful and emerged as platforms enabling rapid development and large-scale preparation. Here, we develop two MPXV quadrivalent mRNA vaccines, named mRNA-A-LNP and mRNA-B-LNP, based on two intracellular mature virus specific proteins (A29L and M1R) and two extracellular enveloped virus specific proteins (A35R and B6R). By administering mRNA-A-LNP and mRNA-B-LNP intramuscularly twice, mice induce MPXV specific IgG antibodies and potent vaccinia virus (VACV) specific neutralizing antibodies. Further, it elicits efficient MPXV specific Th-1 biased cellular immunity, as well as durable effector memory T and germinal center B cell responses in mice. In addition, two doses of mRNA-A-LNP and mRNA-B-LNP are protective against the VACV challenge in mice. And, the passive transfer of sera from mRNA-A-LNP and mRNA-B-LNP-immunized mice protects nude mice against the VACV challenge. Overall, our results demonstrate that mRNA-A-LNP and mRNA-B-LNP appear to be safe and effective vaccine candidates against monkeypox epidemics, as well as against outbreaks caused by other orthopoxviruses, including the smallpox virus.
Topics: Animals; Mice; Vaccinia virus; Monkeypox virus; Mpox (monkeypox); Vaccines, Combined; Mice, Nude; COVID-19; Viral Proteins; Immunity
PubMed: 37117161
DOI: 10.1038/s41392-023-01432-5 -
The Lancet. Microbe Sep 2022
Topics: Humans; Mpox (monkeypox); Monkeypox virus
PubMed: 36058231
DOI: 10.1016/S2666-5247(22)00233-6 -
Nature Aug 2023Human tripartite motif protein 5α (TRIM5α) is a well-characterized restriction factor for some RNA viruses, including HIV; however, reports are limited for DNA...
Human tripartite motif protein 5α (TRIM5α) is a well-characterized restriction factor for some RNA viruses, including HIV; however, reports are limited for DNA viruses. Here we demonstrate that TRIM5α also restricts orthopoxviruses and, via its SPRY domain, binds to the orthopoxvirus capsid protein L3 to diminish virus replication and activate innate immunity. In response, several orthopoxviruses, including vaccinia, rabbitpox, cowpox, monkeypox, camelpox and variola viruses, deploy countermeasures. First, the protein C6 binds to TRIM5 via the RING domain to induce its proteasome-dependent degradation. Second, cyclophilin A (CypA) is recruited via interaction with the capsid protein L3 to virus factories and virions to antagonize TRIM5α; this interaction is prevented by cyclosporine A (CsA) and the non-immunosuppressive derivatives alisporivir and NIM811. Both the proviral effect of CypA and the antiviral effect of CsA are dependent on TRIM5α. CsA, alisporivir and NIM811 have antiviral activity against orthopoxviruses, and because these drugs target a cellular protein, CypA, the emergence of viral drug resistance is difficult. These results warrant testing of CsA derivatives against orthopoxviruses, including monkeypox and variola.
Topics: Humans; Antiviral Agents; Antiviral Restriction Factors; Capsid Proteins; Cell Line; Cyclophilin A; Poxviridae; Tripartite Motif Proteins; Ubiquitin-Protein Ligases; Viral Proteins; Proteasome Endopeptidase Complex
PubMed: 37558876
DOI: 10.1038/s41586-023-06401-0