Molecular cytogenetic characterization of human papillomavirus16-transformed foreskin keratinocyte cell line 16-MT

Establishment and identification of the head kidney cell line of yellowfin seabream (Acanthopagrus latus) and its application in a virus susceptibility study

The yellowfin seabream (Acanthopagrus latus) is a crucial marine resource owing to its economic significance. Acanthopagrus latus aquaculture faces numerous challenges from viral diseases, but a robust in-vitro research model to understand and address these threats is lacking. Therefore, we developed a novel A. latus cell line from head kidney cells called ALHK1. This study details the development, characterisation, and viral susceptibility properties of ALHK cells. This cell line primarily comprises fibroblast-like cells and has robust proliferative capacity when cultured at 28 °C in Leibovitz's L-15 medium supplemented with 10-20% foetal bovine serum. It exhibited remarkable stability after more than 60 consecutive passages and validation through cryopreservation techniques. The specificity of the ALHK cell line's origin from A. latus was confirmed via polymerase chain reaction (PCR) amplification of the cytochrome B gene, and a chromosomal karyotype analysis revealed a diploid count of 48 (2n = 48). Furthermore, the lipofection-mediated transfection efficiency using the pEGFP-N3 plasmid was high, at nearly 40%, suggesting that ALHK cells could be used for studies involving exogenous gene manipulation. In addition, ALHK cells displayed heightened sensitivity to the large mouth bass virus (LMBV), substantiated through observations of cytopathic effects, quantitative real-time PCR, and viral titration assays. Finally, the response of ALHK cells to LMBV infection resulted in differentially expressed antiviral genes associated with innate immunity. In conclusion, the ALHK cell line is a dependable in-vitro platform for elucidating the mechanisms of viral diseases in yellowfin seabream. Moreover, this cell line could be valuable for immunology, vaccine development, and host-pathogen interaction studies.

Establishment and characterization of a brain tissue cell line from spotted knifejaw (Oplegnathus punctatus) and its susceptibility to several fish viruses

Cells are important in the study of virus isolation and identification, viral pathogenic mechanisms and antiviral immunity. The spotted knifejaw (Oplegnathus punctatus) is a significant farmed fish in China that has been greatly affected by diseases in recent years. In this study, a new cell line derived from the spotted knifejaw brain (SKB) was established and characterized. SKB cells multiplied well in Leibovitz's L-15 medium supplemented with 10% fetal bovine serum at 28°C. Chromosome analysis revealed that modal chromosome number was 48 for SKB. SKB cells exhibit susceptibility to several fish viruses, such as a largemouth bass virus, red grouper nervous necrosis virus (RGNNV), infectious spleen and kidney necrosis virus (ISKNV), Singapore grouper iridovirus (SGIV) and spotted knifejaw iridovirus isolate (SKIV-TJ), as shown by cytopathic effect and increased viral titers. Electron microscopy results showed that the cytoplasm contained a large number of vacuoles, and many virus particles existed at the edge of the vacuoles in RGNNV-infected cells and numerous viral particles were scattered throughout the cytoplasm in both ISKNV- and SKIV-TJ-infected cells. These results suggest that SKB is an ideal tool for studying host-virus interactions and potential vaccine development.

Establishment of Immortalized Primary Human Foreskin Keratinocytes and Their Application to Toxicity Assessment and Three Dimensional Skin Culture Construction

In spite of frequent usage of primary human foreskin keratinocytes (HFKs) in the study of skin biology, senescence-induced blockage of in vitro proliferation has been a big hurdle for their effective utilization. In order to overcome this passage limitation, we first isolated ten HFK lines from circumcision patients and successfully immortalized four of them via a retroviral transduction of high-risk human papillomavirus (HPV) E6 and E7 oncogenes. We confirmed expression of a keratinocyte marker protein, keratin 14 and two viral oncoproteins in these immortalized HFKs. We also observed their robust responsiveness to various exogenous stimuli, which was evidenced by increased mRNA expression of epithelial differentiation markers and pro-inflammatory genes in response to three reactive chemicals. In addition, their applicability to cytotoxicity assessment turned out to be comparable to that of HaCaT cells. Finally, we confirmed their differentiation capacity by construction of well-stratified three dimensional skin cultures. These newly established immortalized HFKs will be valuable tools not only for generation of in vitro skin disease models but also for prediction of potential toxicities of various cosmetic chemicals.

Loss of CHFR in human mammary epithelial cells causes genomic instability by disrupting the mitotic spindle assembly checkpoint

CHFR is an E3 ubiquitin ligase and an early mitotic checkpoint protein implicated in many cancers and in the maintenance of genomic stability. To analyze the role of CHFR in genomic stability, by siRNA, we decreased its expression in genomically stable MCF10A cells. Lowered CHFR expression quickly led to increased aneuploidy due to many mitotic defects. First, we confirmed that CHFR interacts with the mitotic kinase Aurora A to regulate its expression. Furthermore, we found that decreased CHFR led to disorganized multipolar mitotic spindles. This was supported by the finding that CHFR interacts with alpha-tubulin and can regulate its ubiquitination in response to nocodazole and the amount of acetylated alpha-tubulin, a component of the mitotic spindle. Finally, we found a novel CHFR interacting protein, the spindle checkpoint protein MAD2. Decreased CHFR expression resulted in the mislocalization of both MAD2 and BUBR1 during mitosis and impaired MAD2/CDC20 complex formation. Further evidence of a compromised spindle checkpoint was the presence of misaligned metaphase chromosomes, lagging anaphase chromosomes, and defective cytokinesis in CHFR knockdown cells. Importantly, our results suggest a novel role for CHFR regulating chromosome segregation where decreased expression, as seen in cancer cells, contributes to genomic instability by impairing the spindle assembly checkpoint.