Skin protects the body by mediating various immune responses against exogenous substances including bacteria, fungi, and viruses, in addition to its predominant role as a physical barrier. Despite the significant protection offered via various mechanisms, bacterial infection of the skin is one of the most common skin diseases in veterinary medicine. This study demonstrated the structural and immunological changes in the skin during infections with Pseudomonas aeruginosa and Staphylococcus pseudintermedius using skin explants from four healthy beagles. Skin structure was generally well preserved in uninfected controls, but defects in skin structure, including injury of keratinocytes and dermal–epidermal junctional disruption, were identified when skin explants were exposed to P. aeruginosa and S. pseudintermedius. On exposure to P. aeruginosa, marked linear cleft formation was noted along with acantholysis along the basal layer after 24 hours of culture. In addition to the defects in the skin structure, mRNA expression levels of the AMPs cBD103 and S100A8 were decreased, which was confirmed by immunohistochemical staining. Taken together, these results suggest that our ex vivo canine skin model is a research tool for investigating bacterial skin infections in dogs.

The T-cell receptor (TCR) engages with an antigen and initiates a signaling cascade that leads to the activation of transcription factors. Roquin, a protein encoded by the RC- 3H1 gene and characterized as an immune regulator, was recently identified as a novel RING-type ubiquitin ligase family member, but the mechanisms by which Roquin regulates T-cell responses are unclear. We used the EL-4 murine lymphoma cell line to elucidate the role of Roquin in vitro. Roquin-overexpressing EL-4 cells became hyper-responsive after anti-CD3/CD28 stimulation in vitro and were a major source of the cytokines IL-2 and TNF-α. Upon activation, these cells showed particularly enhanced production of IL-2 and TNF-α. To clarify the important role played by Roquin in T-cell responses ex vivo, we generated T-cell-specific Roquin transgenic (Tg) mice. Roquin-Tg CD4+ T-cells showed enhanced production of IL-2 and TNF-α in response to TCR stimulation with anti-CD28 co-stimulation. Further studies are necessary to investigate the role of Roquin in the regulation of primary T-cell activation, survival, and differentiation.

Several types of white blood cells, such as T cells, B cells, and macrophages, are involved in the immune response. In particular, the processes of T-cell activation play a crucial role in an adaptive immune response, whereby the T-cell receptor (TCR) engages with an antigen and signals a cascade that leads to the activation of transcription factors (AP-1, NF-κB, and NFAT) that are critically involved in cytokine production. Roquin, encoded by the RC3H1 gene and characterized as an immune regulator, was recently identified as a novel RING-type ubiquitin ligase family member, but the mechanisms by which Roquin proteins regulate T-cell responses are unclear. To elucidate the role of Roquin in vitro, murine lymphoma EL-4 cells were used. Roquin overexpressing Tcells became hyper-responsive upon anti-CD3/CD28 stimulation in vitro and were a major source of cytokines such as IL-2, TNF-α, IL-6, and IL-10. Upon activation, these cells showed preferentially enhanced production of IL-2 and TNF-α, but not IFN-γ. To clarify the important role of Roquin in the T-cell response ex vivo, we generated T-cell-specific Roquin-transgenic (Tg) mice having a higher expression of Roquin in T cells as compared to wild-type mice. Using Roquin-Tg mice, we studied whether immune responses are affected ex vivo. Roquin-Tg CD4+ T cells showed enhanced production of IL-2 or TNF-α to TCR stimulation with anti-CD28 costimulation via up-regulation of CD28. T-cell proliferation also increased in Roquin-Tg CD4+ T cells after anti-CD3/CD28 treatment. Further studies on the role of Roquin in the regulation of primary T-cell activation, survival, and differentiation may be anticipated.

Transducin-like enhancer protein 1(TLE-1) is protein associated with cell proliferation. This study analyzed change of TLE-1 mRNA expression during in vivo and in vitro maturation in porcine oocytes. Oocytes and granulose cells were collected from follicles of <2 mm, 2～6 mm and >6 mm in diameter in slaughtered pig’s ovaries. Oocytes collected from follicles of 2～6 mm in diameter were used after in vitro maturation for 0, 10, 20 and 44 h. Cumulus cells and granulose cells were collected after treatment with hyaluronidase. In results, TLE-1 mRNA expression in oocytes collected from follicle >6 mm in diameter is increased, TLE-1 RNA expression in cumulus cells and granulosa cells from follicles <2 mm, 2 mm 6 mm and >6 mm in diameter. However, there is no significant difference. On the other hand, TLE-1 mRNA expression from oocytes cultured for 10 h and 44 h is increased, TLE-1 mRNA in cumulus cells cultured for 10 h is significant increased(p<0.05) than other culture periods. In conclusion, these results show that TLE-1 is expressed in all cell types of oocytes, cumulus cells and granulose cells, and associated with oocyte maturation.