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Dhungel, P.

Publications and source records attributed to Dhungel, P..

2 recordsLinked to original sources

NTX250: A Modular mRNA-Based Immunotherapy Platform for HPV-Associated Cancers with Broad Applicability.

Infection with high-risk human papillomavirus (HPV) is a key driver of multiple HPV-associated malignancies, including cervical intraepithelial neoplasia (CIN), oropharyngeal, head and neck, and anogenital cancers. Despite the high efficacy of prophylactic HPV vaccines, a substantial population remains at ongoing risk due to issues related to vaccine accessibility, awareness, or personal choice. Current treatments, such as the loop electrosurgical excision procedure (LEEP), address lesions but do not eliminate persistent HPV infection and are associated with potential complications. Moreover, individuals treated for HPV-related disease are at increased risk for subsequent HPV-associated malignancies. These factors underscore an urgent need for effective, non-invasive therapeutic strategies capable of targeting and eradicating persistent HPV infections. Here we introduce NTX250, an innovative mRNA-based therapeutic platform designed to deliver HPV type 16 (HPV16) E6-E7 antigens, combined with immunomodulators human interleukin-12 (IL-12) p70 and engineered human LIGHT (LIGHT). The mRNAs are co-delivered via lipid and ionizable peptoid nanoparticles referred to as Nutshell formulation for intralesional administration. Our preclinical evaluation demonstrates that localized delivery of NTX250 in HPV16-transformed tumor-bearing models results in complete tumor regression and the induction of durable, antigen-specific immune memory. Moreover, this modular mRNA nanoparticle approach combining tumor-specific antigens and immunomodulators is adaptable beyond HPV, with potential applications targeting neoepitopes or other tumor-associated antigens, thus offering a versatile platform for immunotherapy across a broad range of indications. These findings highlight the potential of this strategy as a broadly applicable, non-surgical immunotherapeutic capable of inducing robust and specific anti-tumor responses.

immunology↗

La-related protein 4 is enriched in vaccinia virus factories and is required for efficient viral replication in primary human fibroblasts

In addition to the 3-poly(A) tail, vaccinia virus mRNAs synthesized after viral DNA replication (post-replicative mRNAs) possess a 5-poly(A) leader that confers a translational advantage in virally infected cells. These mRNAs are synthesized in viral factories, the cytoplasmic compartment where vaccinia virus DNA replication, mRNA synthesis, and translation occur. However, a previous study indicates that the poly(A)-binding protein (PABPC1)-which has a well-established role in RNA stability and translation-is not present in the viral factories. This prompts the question of whether another poly(A)-binding protein engages vaccinia virus post-replicative mRNA in viral factories. In this study, we found that La-related protein 4 (LARP4), a poly(A) binding protein, was enriched in viral factories in multiple types of cells during vaccinia virus infection. Further studies showed that LARP4 enrichment in the viral factories required viral post-replicative gene expression and functional decapping enzymes encoded by vaccinia virus. We further showed that knockdown of LARP4 expression in human foreskin fibroblasts (HFFs) significantly reduced vaccinia virus post-replicative gene expression and viral replication. Interestingly, the knockdown of LARP4 expression also reduced 5-poly(A) leader-mediated mRNA translation in vaccinia virus-infected and uninfected HFFs. Together, our results identified a poly(A)-binding protein, LARP4, enriched in the vaccinia virus viral factories and facilitates viral replication and mRNA translation. ImportancePoxviruses are a family of large DNA viruses comprising members infecting a broad range of hosts, including many animals and humans. Poxvirus infections can cause deadly diseases in humans and animals. Vaccinia virus, the prototype poxvirus, encodes over 200 open reading frames (ORFs). Over 90 of vaccinia virus ORFs are transcribed post-viral DNA replication. All these mRNAs contain a 5-poly(A) leader, as well as a 3-poly(A) tail. They are synthesized in viral factories, where vaccinia virus DNA replication, mRNA synthesis and translation occur. However, surprisingly, the poly(A) binding protein (PABPC1) that is important for mRNA metabolism and translation is not present in the viral factories, suggesting other poly(A) binding protein(s) may be present in viral factories. Here we found another poly(A)-binding protein, La-related protein 4 (LARP4), is enriched in viral factories during vaccinia virus infection. We also showed that LARP4 enrichment in the viral factories depends on viral post-replicative gene expression and functional viral decapping enzymes. The knockdown of LARP4 expression in human foreskin fibroblasts (HFFs) significantly reduced vaccinia virus post-replicative gene expression and viral replication. Overall, this study identified a poly(A)-binding protein that plays an important role in vaccinia virus replication.

microbiology↗