pneumoniae. The basal levels of cytokines and
the ones induced by the oral and nasal administration of the probiotic before immunization with recombinant strains (day 0) were determined. With regard to the IL-2 and IFN-γ Th1-type cytokines (Fig. 3a, b), the mice that received L. casei by the oral and nasal routes before administration of the vaccine (day 0) showed a significant increase in IFN-γ. Oral administration of Lc induced greater production of IL-2 compared to the control that received PBS. On days 28 and 42 there was a significant increase in this website IL-2 and IFN-γ in BAL in all the groups treated compared to the control. LL + Lc (O) and D-LL + Lc (O) induced the highest level of IL-2, which would indicate that the probiotic influenced the increase in this cytokine compared to administration of LL [on day 42, LL versus D-LL + Lc (O): P < 0·001, LL versus LL + Lc (O): P < 0·01) and D-LL (D-LL + Lc (O) versus D-LL: P < 0·01, LL + Lc (O) versus D-LL: P < 0·001]. The concentration of IFN-γ in BAL reached highest levels in the group that received LL + Lc (O), followed by D-LL + Lc (N), with significant differences between them (LL + Lc versus selleck inhibitor D-LL + Lc (N): P < 0·01). With regard to the induction of the Th2-type cytokine IL-4, oral and nasal administration of Lc before immunization
with recombinant vaccine (day 0) induced a significant increase in IL-4 in BAL compared to
the control (Fig. 4a). Two weeks after the second (day 28) and third immunizations (day 42) with the recombinant strain, there was a significant increase in IL-4 in all experimental groups compared to the control (day 0). On days 28 and 42, the live and the inactivated vaccine associated with the probiotic strain administered by the oral and nasal routes induced high IL-4 levels in BAL compared HSP90 to both the LL group [day 42, LL versus LL + Lc (O): P < 0·05) and the D-LL group (D-LL + Lc (O) versus D-LL: P < 0·01, D-LL versus D-LL + Lc (N): P < 0·01]. However, it should be noted that the highest levels of this cytokine, which is a marker of the stimulation of Th2 cells, was obtained with the nasal administration of the probiotic strain associated with the inactivated recombinant strain (P < 0·01). The regulatory cytokine IL-10 (Fig. 4b) showed variable behaviour depending upon the experimental group studied. The oral and nasal administrations of Lc induced high IL-10 concentrations compared to the control; however, the association of Lc (administered nasally) with D-LL (D-LL + Lc) induced a similar concentration to the control group on day 28. The highest IL-10 levels were reached 2 weeks after the second immunization (day 28) in the group that received D-LL (P < 0·001) compared to the control.