Journal of Microbiology

Research Support, Non-U.S. Gov't

Dysregulation of KSHV Replication by Extracts from Carthamus tinctorius L.: Han Lee , Hyosun Cho , Myoungki Son , Gi-Ho Sung , Taeho Lee , Sang-Won Lee , Yong Woo Jung , Yu Su Shin , Hyojeung Kang; J. Microbiol. 2013;51(4):490-498. Published online August 30, 2013; DOI: https://doi.org/10.1007/s12275-013-3282-7

Abstract: Carthamus tinctorius L. (CT) is traditionally used to reduce ailments from diseases of the musculoskeletal system and connective tissue and diseases of blood circulation and the cardiovascular system. Flower extracts from CT are known to have antibacterial activity, anti-inflammatory activity, and to inhibit tumor promotion in mouse skin carcinogenesis. In order to discover new antiviral agents from CT extracts, we tested whether CT extracts contain antiviral activity against gammaherpesvirus infection. This study demonstrated that treatment with CT extracts disrupted KSHV latency in the viral-infected host cells, iSLK-BAC16. n-Hexane and EtOH fractions of CT extracts critically affected at least two stages of the KHSV life-cycle by abnormally inducing KSHV lytic reactivation and by severely preventing KSHV virion release from the viral host cells. In addition to the effects on KSHV itself, CT extract treatments induced cellular modifications by dysregulating cell-cycle and producing strong cytotoxicity. This study demonstrated for the first time that CT extracts have antiviral activities that could be applied to development of new anti-gammaherpesviral agents.

A Restrictive Virus Tropism, Latency and Reactivation of Pseudorabies Virus Following Irreversible Deletion of BsrI Restriction Site in the Thymidine-kinase Gene: Mohd Lila Mohd Azmi , Nazariah Allaudin Zeenathul , Abdel-Wahid Saeed Ali , Che Abdul Rahim Mohamed , Awang Isa Kamarudin; J. Microbiol. 2002;40(1):1-10.

Abstract: At the dose of 1000 p.f.u. per mouse, 100% mortality occurred in mice inoculated with wild-type pseudorabies virus (PrV). In contrast, upon stable deletion of 10 bp nucleotides at the BsrI site within the TK gene, PrV was rendered to be completely apathogenic. The deletion also caused the virus to be less capable of replicating in respiratory as well as in nervous system tissues. Although animals were exposed to high titers of TK-deleted PrVs, the virus failed to replicate to a high titer as compared to the pathogenic parental virus. In contrast to previous studies, the deletion in the TK gene did not prevent the virus from establishing latency. Upon immunosuppression, the latent virus, however, reactivated but replicated at low titers. Interestingly, TK-deleted virus established latency and reactivation, that are occurred only in trigeminal ganglia and the cerebrum, and no other tissues involved. Following reactivation, there was no indication of virus shedding in respiratory tissues as confirmed by virus isolation and polymerase chain reaction (PCR) technique targeting at the gB gene of PrV. The non-pathogenic virus with non-shedding characteristics, upon reactivation of the latent virus, would be the important feature of a live virus vaccine candidate.

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