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

tel-00827710, version 1 - 29 May 2013
Figure 47. Type I IFN enhance T cell cross-priming at the level of cross-presentation. 5x10 3
CD45.1/2 WT OT-I and 5x10 3 CD45.2/2 IFNAR -/- OT-I were transferred into WT CD45.1/1
recipients. The following day, mice were immunized i.d. with 5x10 5 K bm1 mOva splenocytes. They
received 100µg of poly I:C on day 3. On day 7, enrichment was performed using a CD45.2 antibody
to detect the 2 populations of OT-I. After ex vivo restimulation, IFNγ intracellular staining was
performed. (A) Representative FACS plots are depicted (live DUMP - CD3 + CD8 + CD45.2 + cells are
shown) with the gates corresponding to IFNAR -/- OT-I and WT OT-I producing IFNγ (red and green
gate respectively). The numbers correspond to the percentage of OT-I in each of the gates. The
percentages of IFNγ-producing OT-I (B) as well as the geometric fluorescent mean for IFNγ (C) are
reported.
3) Does late type I IFN act directly on antigen-specific CD8 + T cells?
The same experimental approach was then taken using IFNAR -/- rather than WT recipients.
WT and IFNAR -/- OT-I cells were transferred, mice were immunized and received poly I:C on
day 3. Only WT OT-I cells were able to respond to type I IFN in these mice. An increase in
the percentage of IFNγ−producing cells (Figure 48A) or in the MFI (Figure 48B) for IFNAR -
/- OT-I cells was not observed. In the case of WT OT-I cells, there was only a slight increase
in the MFI, but overall there was not substantial difference based on poly I:C treatment.
Moreover we observed a strong basal level of IFNγ signal in the WT OT-I cells (Figure 48B).
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