RESUMEN
Previously, we demonstrated that post-immunobiotics derived from Lactobacillus gasseri TMT36, TMT39, and TMT40 strains (HK36, HK39 and HK40, respectively) differentially regulated Toll-like receptor 3 (TLR3)-mediated antiviral respiratory immunity in infant mice. In this work, we investigated whether the HK36, HK39 and HK40 nasal treatments were able to improve the resistance against primary respiratory syncytial virus (RSV) infection and secondary pneumococcal pneumonia. Our results demonstrated that the three treatments increased the resistance to primary viral infection by reducing variations in body weight, RSV titers and lung damage of infected infant mice. Post-immunobiotics significantly enhanced the expressions of interferon (IFN)-λ, IFN-ß, IFN-γ, interleukin(IL) - 1ß, IL-6, IL-27, Mx1, RNAseL and 2'-5'-oligoadenylate synthetase 1 (OAS1) genes and decreased tumour necrosis factor (TNF)-α in alveolar macrophages of RSV-challenged mice. In addition, the studies in the model of RSV-Streptococcus pneumoniae superinfection showed that the HK39 and HK40 treatments were capable of reducing lung damage, lung bacterial cell counts, and the dissemination of S. pneumoniae into the blood of infant mice. The protective effect was associated with increases in IFN-ß, IFN-γ, IL-10, and IL-27 in the respiratory tract. This study demonstrates that the nasal application of the post-immunobiotics HK39 and HK40 stimulates innate respiratory immunity and enhances the defences against primary RSV infection and secondary pneumococcal pneumonia offering an alternative to combat respiratory superinfections in children, which can be fatal.
RESUMEN
The activity of 17 alpha-hydroxylase, a key enzyme for progesterone metabolism in avian follicles, was measured in cell-free homogenates of isolated theca cells of Japanese quail. Kinetic studies revealed that differences in enzyme activity in the largest and the second largest follicles were mainly due to differences in Vmax values. In order to investigate the mechanism of regulation of 17 alpha-hydroxylase activity, quail were hypophysectomized at various time periods during the ovulatory cycle, and 17 alpha-hydroxylase activity in theca homogenates was measured 4 h after surgery. Hypophysectomy at 8 h before the predicted time of ovulation, which is the time when the preovulatory luteinizing hormone (LH) surge is initiated, resulted in a significant decrease in enzyme activity. In contrast, activity was increased when the pituitary was removed 20 h before ovulation. Hypophysectomy 24 h before ovulation had no effect on enzyme activity.
