Voie d'immunisation et séquence d'administration de l ... - TEL

tel-00827710, version 1 - 29 May 2013
were transferred only three days after immunization and thus were not present during the peak
of type I IFN production (Figure 40). Therefore, the impact of the defect in IFN-
responsiveness of the IFNAR -/- OT-I cells may be underestimated here. These results should
be further confirmed by performing the same experiment, with the OT-I transfer made prior to
adjuvant delivery.
Figure 45. Type I IFN do not act on T cells transferred three days post-immunization. C57BL/6
CD45.1/1 mice were immunized with 5x10 5 K bm1 mOva splenocytes. Mice received 100µg of poly I:C
7 hours post-immunization. On day 3, WT CD45.1/2 and IFNAR -/- CD45.2/2 CFSE-labeled OT-I
splenocytes were transferred. Three days later, the proliferation of the two populations of CD8 + OT-I
was assessed. The percentage of undivided OT-I was shown for each population.
C. Enhancement of cross-priming after late type I IFN production
Using the same model, we performed similar experiments to further understand the
mechanisms underlying the enhancement of cross-priming upon late adjuvant delivery.
1) Enhancement of cross-priming upon late poly I:C delivery is type I IFNdependent
The T cell response was studied in WT, IFNAR -/- and IRF3/7DKO mice to determine whether
the enhancement of cross-priming upon late poly I:C administration is dependent on type I
IFN signaling. These three mouse lines were immunized i.d. with K bm1 mOva splenocytes and
received poly I:C three days later. On day 10, cells from the spleen and the draining lymph
node were harvested to perform an IFNγ-ELISPOT. As expected, a higher number of CD8 + T
cells secrete IFNγ in WT mice that received poly I:C than those that received antigen alone.
This enhancement was not observed for IFNAR -/- or IRF3/7 DKO mice confirming that late
poly I:C treatment boosts cross-priming in a type I IFN-dependent manner (Figure 46).
Page 127 of 256