Current opinion in virology最新文献

Acute hyperinflammatory virus infections, such as influenza or coronavirus disease-19, are still a major health burden worldwide. In these diseases, a massive overproduction of pro-inflammatory cytokines and chemokines (cytokine storm syndrome) determine the severity of the disease, especially in late stages. Direct-acting antivirals against these pathogens have to be administered very early after infection to be effective and may induce viral resistance. Here, we summarize data on a host-targeted strategy using inhibitors of the cellular Raf/MEK/ERK kinase cascade that not only block replication of different RNA viruses but also suppress the hyperinflammatory cytokine response upon infection. In the first phase-II clinical trial of that approach, the MEK inhibitor Zapnometinib shows evidence of clinical benefit.

While receptor binding is well recognized as a factor in influenza-A virus (IAV) and coronavirus (CoV) host adaptation, the role of viral glycoprotein cleavage has not been studied in detail so far. Interestingly, recent studies suggest that host species may differ in their protease repertoire available for cleavage. Furthermore, it was shown for certain bat-derived CoVs that proteolytic activation provides a critical barrier to infect human cells. Understanding the role of glycoprotein cleavage in different species and how IAV and CoVs adapt to a new protease repertoire may allow evaluating the zoonotic potential and risk posed by these viruses. Here, we summarize the current knowledge on the emergence of a multibasic cleavage site (CS) in the glycoproteins of IAVs and CoVs in different host species. Additionally, we discuss the role of transmembrane serine protease 2 (TMPRSS2) in virus activation and entry and a role of neuropilin-1 in acquisition of a multibasic CS in different hosts.

Multi-drug-resistant bacteria are associated with significantly higher morbidity and mortality. The possibilities for discovering new antibiotics are limited, but phage therapy — the use of bacteriophages (viruses infecting bacteria) to cure infections — is now being investigated as an alternative or complementary treatment to antibiotics. However, one of the major limitations of this approach lies in the antagonistic coevolution between bacteria and bacteriophages, which determines the ultimate success or failure of phage therapy. Here, we review the possible influence of the animal host on phage resistance and its consequences for the efficacy of phage therapy. We also discuss the value of in vitro assays for anticipating the dynamics of phage resistance observed in vivo.

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive hematologic malignancy linked to HTLV-1 infection, which is refractory to therapy. The precise mechanism of oncogenesis in ATLL is incompletely understood, however, oncogenic viral genes Tax and Hbz are implicated, and recent large genomic and transcriptome studies provide further insight. Despite progress in understanding the disease, survival and outcome with current therapies remain poor. Long-term survivors are reported, primarily among those with indolent disease or activating CC chemokine receptor 4 mutations, however, allogeneic hematopoietic stem cell transplant is the only curative treatment option. The majority of patients succumb to their disease and ongoing and collaborative research efforts are needed. I will review recent updates in HTLV-1-associated ATLL epidemiology, pathogenesis, therapy, and prevention.

Global metagenomic surveys have revealed that bats host a diverse array of paramyxoviruses, including species from at least five major genera. An essential determinant of successful spillover is the entry of a virus into a new host. We evaluate the role of receptor usage in the zoonotic potential of bat-borne henipaviruses, morbilliviruses, pararubulaviruses, orthorubulaviruses, and jeilongviruses; successful spillover into humans depends upon compatibility of a respective viral attachment protein with its cognate receptor. We also emphasize the importance of postentry restrictions in preventing spillover. Metagenomics and characterization of newly identified paramyxoviruses have greatly improved our understanding of spillover determinants, allowing for better forecasts of which bat-borne viruses may pose the greatest risk for cross-species transmission into humans.

The capacity of host cells to detect and restrict an infecting virus rests on an array of cell-autonomous antiviral effectors and innate immune receptors that can trigger inflammatory processes at tissue and organismal levels. Dynamic changes in protein abundance, subcellular localisation, post-translational modifications and interactions with other biomolecules govern these processes. Proteomics is therefore an ideal experimental tool to discover novel mechanisms of host antiviral immunity. Additional information can be gleaned both about host and virus by systematic analysis of viral immune evasion strategies. In this review, we summarise recent advances in proteomic technologies and their application to antiviral innate immunity.

The Bunyavirales order is the largest grouping of RNA viruses, comprising emerging and re-emerging human, plant and animal pathogens. Bunyaviruses have a global distribution and many members of the order are transmitted by arthropods. They have evolved a plethora of mechanisms to manipulate the regulatory processes of the infected cell to facilitate their own replicative cycle, in hosts of disparate phylogenies. Interest in virus-vector interactions is growing rapidly. However, current understanding of tick-borne bunyavirus cellular interaction is heavily biased to studies conducted in mammalian systems. In this short review, we summarise current understandings of how tick-borne bunyaviruses utilise major cellular pathways (innate immunity, apoptosis and RNAi responses) in mammalian or tick cells to facilitate virus replication.

The COVID-19 pandemic has accelerated the development of nucleoside analogs to treat respiratory virus infections, with remdesivir being the first compound to receive worldwide authorization and three other nucleoside analogs (i.e. favipiravir, molnupiravir, and bemnifosbuvir) in the pipeline. Here, we summarize the current knowledge concerning their clinical efficacy in suppressing the virus and reducing the need for hospitalization or respiratory support. We also mention trials of favipiravir and lumicitabine, for influenza and respiratory syncytial virus, respectively. Besides, we outline how nucleoside analogs interact with the polymerases of respiratory viruses, to cause lethal virus mutagenesis or disturbance of viral RNA synthesis. In this way, we aim to convey the key findings on this rapidly evolving class of respiratory virus medication.

Poxviruses are a diverse family of double-stranded DNA viruses that cause mild-to-severe disease in selective hosts, including humans. Although most poxviruses are restricted to their hosts, some members can leap host species and cause zoonotic diseases and, therefore, are genuine threats to human and animal health. The recent global spread of monkeypox in humans suggests that zoonotic poxviruses can adapt to a new host, spread rapidly in the new host, and evolve to better evade host innate barriers. Unlike many other viruses, poxviruses express an extensive repertoire of self-defense proteins that play a vital role in the evasion of host innate and adaptive immune responses in their newest host species. The function of these viral immune modulators and host-specific cytokine responses can result in different host tropism and poxvirus disease progression. Here, we review the role of different cytokines that control poxvirus host tropism and adaptation.