Sensitivity of a Novel Lizard-Derived Cell Line (Z1) to Measles, Rubella and Respiratory Syncytial Viruses

The objective of this study was to assess the sensitivity of the Z1 cell line to measles, rubella, and respiratory syncytial viruses (RSVs), and to observe the subsequent cytopathic effects (CPEs) that result from these viruses. The study sought to determine the potential of the Z1 cell line as a suitable alternative for more efficient isolation and identification of these viruses, as well as for conducting quality control tests, such as potency tests and the production of biological products, including diagnostic antigens. The Z1 cell lines were prepared in disposable cell culture flasks and were inoculated with Measles, Rubella, and Respiratory Syncytial Viruses at defined multiplicity of infection. Vero-WHO, Rabbit Kidney-13 (RK-13), and Hep-2 cell lines were also prepared as standard cell substrates and were inoculated with measles, rubella, and respiratory syncytial viruses, respectively. The quality and quantity of CPE formation, i.e., the microscopic signs of viral replication, were observed daily in the test and control cell lines. Samples were collected for the purpose of calculating the titer of progeny viruses, which was then used to compare the viral yield. An interference test using the Vesicular Stomatitis Virus (VSV) was also performed to confirm the replication of Rubella in the Rubella-inoculated cell cultures. In the case of Measles Virus, a significant difference was observed between viral yield in Z1 and Vero-WHO cells. A similar outcome was observed for the Rubella virus, with significant disparities in viral yield observed between Z1 and RK-13 cells. However, when Respiratory Syncytial Virus was inoculated into the Z1 and Vero-WHO cells, no significant differences in viral yield were observed. Consequently, the Z1 cell line emerges as a promising substitute for Hep-2 cells, particularly for the isolation and propagation of Respiratory Syncytial Virus. However, it should be noted that the Z1 cell line exhibits a higher susceptibility to Measles Virus. However, the Z1 cell line was not found to be a suitable substrate for the propagation of Rubella Virus.