Background: In suckling piglets, transmissible gastroenteritis virus (TGEV) causes lethal diarrhea accompanied by high infection and mortality rates, leading to considerable economic losses. This study explored methods of preventing or inhibiting their production.Bovine antimicrobial peptide-13 (APB-13) has antibacterial, antiviral, and immune functions. Objectives: This study analyzed the efficacy of APB-13 against TGEV through in vivo and in vitro experiments. Methods: The effects of APB-13 toxicity and virus inhibition rate on swine testicular (ST) cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). The impact of APB-13 on virus replication was examined through the 50% tissue culture infective dose (TCID50 ). The mRNA and protein levels were investigated by real-time quantitative polymerase chain reaction and western blot (WB). Tissue sections were used to detect intestinal morphological development. Results: The safe and effective concentration range of APB-13 on ST cells ranged from 0 to 62.5 µg/mL, and the highest viral inhibitory rate of APB-13 was 74.1%. The log10 TCID50 of 62.5 µg/mL APB-13 was 3.63 lower than that of the virus control. The mRNA and protein expression at 62.5 µg/mL APB-13 was significantly lower than that of the virus control at 24 hpi. Piglets in the APB-13 group showed significantly lower viral shedding than that in the virus control group, and the pathological tissue sections of the jejunum morphology revealed significant differences between the groups. Conclusions APB-13 exhibited good antiviral effects on TGEV invivo and in vitro.

Integrin alphavbeta3 plays a major role in various signaling pathways, cell apoptosis, and tumor angiogenesis. To examine the functions and roles of alphavbeta3 integrin, a stable CHO-677 cell line expressing the murine alphavbeta3 heterodimer (designated as "CHO-677-malphavbeta3" cells) was established using a highly efficient lentiviral-mediated gene transfer technique. Integrin subunits alphav and beta3 were detected at the gene and protein levels by polymerase chain reaction (PCR) and indirect immunofluorescent assay (IFA), respectively, in the CHO-677-malphavbeta3 cell line at the 20th passage, implying that these genes were successfully introduced into the CHO-677 cells and expressed stably. A plaque-forming assay, 50% tissue culture infective dose (TCID50), real-time quantitative reverse transcription-PCR, and IFA were used to detect the replication levels of Foot-and-mouth disease virus (FMDV) in the CHO-677-malphavbeta3 cell line. After infection with FMDV/O/ZK/93, the cell line showed a significant increase in viral RNA and protein compared with CHO-677 cells. These findings suggest that we successfully established a stable alphavbeta3-receptor-expressing cell line with increased susceptibility to FMDV. This cell line will be very useful for further investigation of alphavbeta3 integrin, and as a cell model for FMDV research.
Animals ; Animals, Suckling ; CHO Cells ; Cloning, Molecular ; Cricetulus ; DNA, Complementary/genetics/metabolism ; Disease Susceptibility/virology ; Foot-and-Mouth Disease/*genetics/virology ; Foot-and-Mouth Disease Virus/*physiology ; Integrin alphaVbeta3/*genetics/metabolism ; Mice

Monitoring neuronal activity in vivo is critical to understanding the physiological or pathological functions of the brain. Two-photon Ca imaging in vivo using a cranial window and specific neuronal labeling enables real-time, in situ, and long-term imaging of the living brain. Here, we constructed a recombinant rabies virus containing the Ca indicator GCaMP6s along with the fluorescent protein DsRed2 as a baseline reference to ensure GCaMP6s signal reliability. This functional tracer was applied to retrogradely label specific V1-thalamus circuits and detect spontaneous Ca activity in the dendrites of V1 corticothalamic neurons by in vivo two-photon Ca imaging. Notably, we were able to record single-spine spontaneous Ca activity in specific circuits. Distinct spontaneous Ca dynamics in dendrites of V1 corticothalamic neurons were found for different V1-thalamus circuits. Our method can be applied to monitor Ca dynamics in specific input circuits in vivo, and contribute to functional studies of defined neural circuits and the dissection of functional circuit connections.