Infectious Agents and Cancer最新文献

Avian leukosis virus Subgroup-J (ALV-J) is an avian retrovirus affecting a wide range of avian species, and has posed a great threat to the local poultry with significant losses. In Egypt, ALV-J has been actively monitored in various breeder flocks. This study investigated 200 eggs from ALV-J positive breeders, confirmed positive-polymerase chain reaction (PCR)-ALV-J, collected from a hatchery between January 2022 and December 2023. 200 tissue specimens (liver, heart, spleen, kidney, and lung) were collected from suspected embryos for PCR test, immunopathological identification, and sequencing analysis. To the best of our understanding, this is the first study specifically detecting ALV-J infection in chicken embryos in Egypt. The current study focuses on the genetic evolution and sequencing analysis of ALV-J isolates from chicken embryos across three Egyptian governorates: El-Sharkia, Al-Qalyubiya, and New Valley. Postmortem findings of the infected embryos showed stunting, curling, dwarfing, hemorrhagic body surface, enlarged liver, and congestion of chorio-allantoic membranes (CAM). Histopathological observation demonstrated no lymphoid or myeloid cell infiltrations, only degenerative changes and congestion of the examined organs existed. The immunohistochemical staining confirmed that the viral-positive signals were visceral tissues as the spleen, liver, and kidney. Only 30 samples were PCR-positive for ALV-J gp85 gene at size of 545 base pairs with a prevalence rate of 15%. Two ALV-J positive samples were sequenced and deposited in the Genbank under accession numbers (PQ119499 - PQ119500, ALV-J-II). ALV-J-gp85 gene phylogeny showed that the AlQalyubiya-1-EGYALVJ-env isolate is highly genetically correlated to Chinese strains (KJ179914-ALV-J-GD27, KJ179912-ALV-J-GD19, KJ179911-ALV-J-GD31) with nucleotide and amino acid identities of 98-100%; respectively. Moreover, Newvalley-2-EGYALVJ-env isolate is close similar to previous mentioned Chinese strains with nucleotide identity percentages of 98% and amino acid identity percentage 97%, 96%, 96%; respectively. This study confirmed that our two ALV-J isolates are not completely similar to the current Egyptian isolates. Also, ALV-J infection was continuously distributed in the breeders and considered one of the factors contributing to the tumor epidemics.

Despite the availability of preventative HPV vaccinations, cervical cancer remains a worldwide health concern. It is mostly caused by persistent infection with high-risk human papillomaviruses. Therapeutic techniques targeting the viral oncogenes E6 and E7, which are constitutively expressed in HPV-positive cervical cancers and inactivate the important tumor suppressors, p53 and Rb, offer intriguing molecular treatment options. RNA-based techniques, such as tiny interfering RNA, short hairpin RNA, antisense oligonucleotides, and mRNA-based vaccines for the selective silencing of E6/E7 genes, have emerged as leaders in targeted therapeutics. Preclinical studies have shown that RNA-mediated suppression of E6/E7 can restore p53 and Rb activity, causing apoptosis or senescence in cervical cancer cells and inhibiting tumor growth in animal models. Similarly, mRNA vaccination platforms encoding E6/E7 have been found to potently induce HPV T-cell responses and full tumor regression in animal models. RNA-based therapeutics in patients are now being evaluated in early-stage clinical studies, including novel mRNA vaccines for HPV-positive malignancies in combination with immunotherapies. While no RNA-based treatment for cervical cancer has yet achieved regulatory approval, this review summarizes the significant progress in this field that has been effective in therapies for cervical cancer using new strategies, such as advanced delivery systems, combinatorial treatments, and genome editing strategies.