Baculovirus is a type of virus with a double stranded, circular, and super helical DNA structure, whose transcription, replication and assembly of offspring virus occur in the nucleus of the cell. However, due to the natural barrier of the cellular nuclear membrane, macromolecular substances larger than 40-60 kDa cannot directly penetrate the nuclear membrane. Therefore, baculovirus have evolved various strategies to achieve transmembrane transport of viral proteins. This article attempts to review the recent literature on mechanisms by which the DNA baculoviruses of insects transport proteins into the infected host cell nucleus. In this article, we summarise the studies of nuclear localisation signals(NLSs) in baculovirus, which are involved in the classical nuclear import pathways and review the non-classical nuclear transport pathways independent on NLS derived from baculovirus. Moreover, during the protein nuclear transport process, viruses will regulate the nuclear pathway through protein modifications. Host structure changes and other methods will create a favorable environment for the nuclear transport of viral proteins.

The chemopreventive effects of various mixed cereal grain (MCG) samples on azoxymethane (AOM, 10 mg/kg) and dextran sulfate sodium (DSS, 2% w/v)-induced colorectal cancer (CRC) in C57BL/6J mice were studied. The main MCG preparation consisted of fermented brown rice (FBR), glutinous brown rice, glutinous Sorghum bicolor, glutinous Panicum miliaceum, Coix lacryma-jobi and black soybean at an appropriate mixing ratio. Other MCG preparations contained rice coated with 5% Phellinus linteus and 5% Curcuma longa (MGR-PC), or 10% Phellinus linteus (MCG-P), or 10% Curcuma longa (MCG-C). Consumption of dietary MCG-PC by CRC mice significantly increased colon length, decreased the ratio of colon weight to length, and reduced the number of colon tumors. Similar effects, although to a lower extent, were observed in CRC mice fed with MCG-P, followed by those fed with MCG-C, MCG, FBR or white rice (WR). MCG-PC significantly suppressed colonic neoplasia, and decreased the levels of various cytokines (tumor necrosis factor: Tnf, interleukin 1 beta: Il1b, interleukin 6: Il6, and interferon gamma: Ifng) in serum and colon tissue of the CRC mice. In addition, MCG-PC increased the mRNA expressions of tumor protein p53(Tp53) and cyclin-dependent kinase inhibitor 1A(Cdkn1a), activated pro-apoptotic caspase 3(Casp3), and reduced expression of both mRNA and protein of inducible inducible nitric oxide synthase 2 (Nos2), prostaglandin-endoperoxide synthase 2 (Ptgs2), and cyclin D1(Ccnd1) in colon tissue. These findings suggest that than compared with other cereal grain preparations, MCG-PC had a greater activity against AOM/DSS-induced CRC by reducing intestinal inflammation, and modulating the expression of certain carcinogenesis related factors (Nos2, Ptgs2, Tp53, Cdkn1a, Ccnd1 and Casp3) in colon tissue of CRC mice.

Feline calicivirus (FCV) causes upper respiratory tract disease (URTD) and sporadic outbreaks of virulent systemic disease (FCV-VSD). The basis for the increased pathogenicity of FCV-VSD viruses is incompletely understood, and antivirals for FCV have yet to be developed. We investigated the clinicoepidemiology and viral features of three FCV-VSD outbreaks in Australia and evaluated the in vitro efficacy of nitazoxanide (NTZ), 2’-C-methylcytidine (2CMC) and NITD-008 against FCV-VSD viruses. Overall mortality among 23 cases of FCV-VSD was 39%. Metagenomic sequencing identified five genetically distinct FCV lineages within the three outbreaks, all seemingly evolving in situ in Australia. Notably, no mutations that clearly distinguished FCV-URTD from FCV-VSD phenotypes were identified. One FCV-URTD strain likely originated from a recombination event. Analysis of seven amino acid residues from the hypervariable E region of the capsid in the cultured viruses provided no support for the contention that properties of these residues can reliably differentiate between the two pathotypes. On plaque reduction assays, dose-response inhibition of FCV-VSD was obtained with all antivirals at low micromolar concentrations; NTZ EC50, 0.4-0.6 µM, TI 21; 2CMC EC50, 2.7-5.3 µM, TI >18; NITD-008, 0.5 to 0.9 µM, TI >111. Investigation of these antivirals for treatment of FCV-VSD is warranted.