Monkeypox: A new threat at our doorstep!

Integrated bioinformatics approaches to investigate alterations in transcriptomic profiles of monkeypox infected human cell line model

BACKGROUND

The recent re-emergence of the monkeypox (mpox) epidemic in nonendemic regions has raised concerns regarding a potential global outbreak. The mpox virus (MPV) is a smallpox-like virus belonging to the genus Orthopoxvirus (family: Poxviridae). Although studies suggest that MPV infection suppresses the Toll-like receptor-3- and tumor necrosis factor-α-related signaling pathways, whether MPV regulates other immune-related pathways remains unclear.

METHODS

In this study, two distinct temporal patterns were used for establishing an MPV-infected human immortal epithelial cancer cell line (HeLa). These two durations 2 and 12 h of incubation were selected to identify the coregulated genes and pathways affected by MPV infection.

RESULTS

The use of the Gene Ontology framework, Kyoto Encyclopedia of Genes and Genome database, and MetaCore software yielded valuable insights. Specifically, various pathways were found to be enriched in HeLa cells infected with MPV for 2 and 12 h. These pathways included Notch, CD40, CD95, hypoxia-inducible factor-1-α, interleukin (IL)- 1, IL-6, phosphoinositide 3-kinase, nuclear factor-κB, mitogen-activated protein kinase, and oxidative stress-induced signalling pathways. Clusters and pathways of metabolism and viral replication cycles were significantly associated with the 2-hour infection group. This association was identified based on the regulation of genes such as HSPG2, RHPN2, MYL1, ASPHD2, CA9, VIPR1, SNX12, MGC2752, SLC25A1, PEX19, and AREG. Furthermore, clusters and pathways related to immunity and cell movement were found to be associated with the 12-hour infection group. This association was identified based on the regulation of genes such as C1orf21, C19orf48, HRK, IL8, GULP1, SCAND2, ATP5C1, FEZ1, SGSH, TACC2, CYP4X1, MMP1, CPB1, P2RY13, WDR27, PRPF4, and ENDOD1.

CONCLUSIONS

This study can improve our understanding of the mechanisms underlying the pathophysiology and post-infection sequelae of mpox. Our findings provide valuable insights into the various modes of MPV infection.

The Global Monkeypox (Mpox) Outbreak: A Comprehensive Review

Monkeypox (Mpox) is a contagious illness that is caused by the monkeypox virus, which is part of the same family of viruses as variola, vaccinia, and cowpox. It was first detected in the Democratic Republic of the Congo in 1970 and has since caused sporadic cases and outbreaks in a few countries in West and Central Africa. In July 2022, the World Health Organization (WHO) declared a public-health emergency of international concern due to the unprecedented global spread of the disease. Despite breakthroughs in medical treatments, vaccines, and diagnostics, diseases like monkeypox still cause death and suffering around the world and have a heavy economic impact. The 85,189 reported cases of Mpox as of 29 January 2023 have raised alarm bells. Vaccines for the vaccinia virus can protect against monkeypox, but these immunizations were stopped after smallpox was eradicated. There are, however, treatments available once the illness has taken hold. During the 2022 outbreak, most cases occurred among men who had sex with men, and there was a range of 7-10 days between exposure and the onset of symptoms. Three vaccines are currently used against the Monkeypox virus. Two of these vaccines were initially developed for smallpox, and the third is specifically designed for biological-terrorism protection. The first vaccine is an attenuated, nonreplicating smallpox vaccine that can also be used for immunocompromised individuals, marketed under different names in different regions. The second vaccine, ACAM2000, is a recombinant second-generation vaccine initially developed for smallpox. It is recommended for use in preventing monkeypox infection but is not recommended for individuals with certain health conditions or during pregnancy. The third vaccine, LC16m8, is a licensed attenuated smallpox vaccine designed to lack the B5R envelope-protein gene to reduce neurotoxicity. It generates neutralizing antibodies to multiple poxviruses and broad T-cell responses. The immune response takes 14 days after the second dose of the first two vaccines and 4 weeks after the ACAM2000 dose for maximal immunity development. The efficacy of these vaccines in the current outbreak of monkeypox is uncertain. Adverse events have been reported, and a next generation of safer and specific vaccines is needed. Although some experts claim that developing vaccines with a large spectrum of specificity can be advantageous, epitope-focused immunogens are often more effective in enhancing neutralization.

Identification and Investigation of a Cryptic Binding Pocket of the P37 Envelope Protein of Monkeypox Virus by Molecular Dynamics Simulations

The spread of the monkeypox virus has surged during the unchecked COVID-19 epidemic. The most crucial target is the viral envelope protein, p37. However, lacking p37's crystal structure is a significant hurdle to rapid therapeutic discovery and mechanism elucidation. Structural modeling and molecular dynamics (MD) of the enzyme with inhibitors reveal a cryptic pocket occluded in the unbound structure. For the first time, the inhibitor's dynamic flip from the active to the cryptic site enlightens p37's allosteric site, which squeezes the active site, impairing its function. A large force is needed for inhibitor dissociation from the allosteric site, ushering in its biological importance. In addition, hot spot residues identified at both locations and discovered drugs more potent than tecovirimat may enable even more robust inhibitor designs against p37 and accelerate the development of monkeypox therapies.

Emergence of monkeypox: a worldwide public health crisis

The human monkeypox virus (MPV), a zoonotic illness that was hitherto solely prevalent in Central and West Africa, has lately been discovered to infect people all over the world and has become a major threat to global health. Humans unintentionally contract this zoonotic orthopoxvirus, which resembles smallpox, when they come into contact with infected animals. Studies show that the illness can also be transferred through frequent proximity, respiratory droplets, and household linens such as towels and bedding. However, MPV infection does not presently have a specified therapy. Smallpox vaccinations provide cross-protection against MPV because of antigenic similarities. Despite scant knowledge of the genesis, epidemiology, and ecology of the illness, the incidence and geographic distribution of monkeypox outbreaks have grown recently. Polymerase chain reaction technique on lesion specimens can be used to detect MPV. Vaccines like ACAM2000, vaccinia immune globulin intravenous (VIG-IV), and JYNNEOS (brand name: Imvamune or Imvanex) as well as FDA-approved antiviral medications such as brincidofovir (brand name: Tembexa), tecovirimat (brand name: TPOXX or ST-246), and cidofovir (brand name: Vistide) are used as therapeutic medications against MPV. In this overview, we provide an outline of the MPV's morphology, evolution, mechanism, transmission, diagnosis, preventative measures, and therapeutic approaches. This study offers the fundamental information required to prevent and manage any further spread of this emerging virus.

Monkeypox infection: The past, present, and future

Monkeypox is a zoonotic illness caused by the monkeypox virus (MPXV) that has a similar etiology to smallpox. The first case of monkeypox was reported in Western and Central Africa in 1971, and in 2003, there was an outbreak of monkeypox viruses outside Africa. According to the World Health Organization (WHO) and Center for Disease Control and Prevention (CDC), monkeypox is transmitted through direct contact with infected animals or persons exposed to infectious sores, scabs, or body fluids. Also, intimate contact between people during sex, kissing, cuddling, or touching parts of the body can result in the spreading of this disease. The use of the smallpox vaccine against monkeypox has several challenges and hence anti-virals such as cidofovir, brincidofovir, and tecovirimat have been used for the symptomatic relief of patients and reversing the lesion formation on the skin. Despite the recent outbreak of monkeypox most especially in hitherto non-endemic countries, there is still a lack of definitive treatment for monkeypox. In the present review, emphasis was focused on etiopathology, transmission, currently available therapeutic agents, and future targets that could be explored to halt the progression of monkeypox. From our review we can postulate that owing to the lack of a definitive cure to this reemerging disorder, there is a need for general awareness about the transmission as well as to develop appropriate diagnostic procedures, immunizations, and antiviral medication.

Monkeypox: epidemiology, pathogenesis, treatment and prevention

Monkeypox is a zoonotic disease that was once endemic in west and central Africa caused by monkeypox virus. However, cases recently have been confirmed in many nonendemic countries outside of Africa. WHO declared the ongoing monkeypox outbreak to be a public health emergency of international concern on July 23, 2022, in the context of the COVID-19 pandemic. The rapidly increasing number of confirmed cases could pose a threat to the international community. Here, we review the epidemiology of monkeypox, monkeypox virus reservoirs, novel transmission patterns, mutations and mechanisms of viral infection, clinical characteristics, laboratory diagnosis and treatment measures. In addition, strategies for the prevention, such as vaccination of smallpox vaccine, is also included. Current epidemiological data indicate that high frequency of human-to-human transmission could lead to further outbreaks, especially among men who have sex with men. The development of antiviral drugs and vaccines against monkeypox virus is urgently needed, despite some therapeutic effects of currently used drugs in the clinic. We provide useful information to improve the understanding of monkeypox virus and give guidance for the government and relative agency to prevent and control the further spread of monkeypox virus.

Comparison of Transcriptomic Signatures between Monkeypox-Infected Monkey and Human Cell Lines

Monkeypox virus (MPV) is a smallpox-like virus belonging to the genus Orthopoxvirus of the family Poxviridae. Unlike smallpox with no animal reservoir identified and patients suffering from milder symptoms with less mortality, several animals were confirmed to serve as natural hosts of MPV. The reemergence of a recently reported monkeypox epidemic outbreak in nonendemic countries has raised concerns about a global outburst. Since the underlying mechanism of animal-to-human transmission remains largely unknown, comprehensive analyses to discover principal differences in gene signatures during disease progression have become ever more critical. In this study, two MPV-infected in vitro models, including human immortal epithelial cancer (HeLa) cells and rhesus monkey (Macaca mulatta) kidney epithelial (MK2) cells, were chosen as the two subjects to identify alterations in gene expression profiles, together with co-regulated genes and pathways that are affected during monkeypox disease progression. Using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and MetaCore analyses, we discovered that elevated expression of genes associated with interleukins (ILs), G protein-coupled receptors (GPCRs), heat shock proteins (HSPs), Toll-like receptors (TLRs), and metabolic-related pathways play major roles in disease progression of both monkeypox-infected monkey MK2 and human HeLa cell lines. Interestingly, our analytical results also revealed that a cluster of differentiation 40 (CD40), plasmin, and histamine served as major regulators in the monkeypox-infected monkey MK2 cell line model, while interferons (IFNs), macrophages, and neutrophil-related signaling pathways dominated the monkeypox-infected human HeLa cell line model. Among immune pathways of interest, apart from traditional monkeypox-regulated signaling pathways such as nuclear factor- (NF-κB), mitogen-activated protein kinases (MAPKs), and tumor necrosis factors (TNFs), we also identified highly significantly expressed genes in both monkey and human models that played pivotal roles during the progression of monkeypox infection, including CXCL1, TNFAIP3, BIRC3, IL6, CCL2, ZC3H12A, IL11, CSF2, LIF, PTX3, IER3, EGR1, ADORA2A, and DUOX1, together with several epigenetic regulators, such as histone cluster family gene members, HIST1H3D, HIST1H2BJ, etc. These findings might contribute to specific underlying mechanisms related to the pathophysiology and provide suggestions regarding modes of transmission, post-infectious sequelae, and vaccine development for monkeypox in the future.