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

tel-00827710, version 1 - 29 May 2013
Figure 44. Early poly I:C affects antigen uptake by cDCs. C57BL/6 CD45.1 + mice were
immunized i.d. with 5x10 6 PKH-26-labeled CD45.2 + K bm1 mOva splenocytes. 7 hours later, mice
received 100µg of poly I:C. On day 2, the draining lymph nodes of several mice were pooled and an
enrichmend for CD11c + cells was performed. Flow cytometry was performed on the enriched fraction
to analyze DC subsets. CD11c + cells are shown (A). In parallel, another flow cytometry analysis was
performed on the ‘flow-through’ fraction to detect the injected lymphocytes that reached the draining
lymph node independent of APCs. CD45.1 and PKH-26 staining were shown for CD3 + (T cells) and
CD19 + cells (B cells) (B).
5) Does early poly I:C treatment act directly on antigen-specific T cells?
We convincingly demonstrated that poly I:C acts on DCs. However, type I IFN have also
been shown to act on T cells directly (Le Bon et al., 2006). To address whether early poly I:C
treatment has a direct effect on antigen-specific T cells in our model, we immunized WT
recipients with K bm1 mOva splenocytes, followed by an injection of poly I:C 7 hours later. On
day 3 post-immunization, CFSE-labeled WT and IFNAR -/- OT-I were transferred and three
days later, the dilution of the CFSE marker was analyzed to examine the proliferative capacity
of the different T cell populations. As shown in Figure 45, the two populations of OT-I cells
displayed the same behavior, suggesting that poly I:C does not differentially regulate WT and
IFNAR -/- OT-I (Figure 45). However, one caveat to this experiment is that the OT-I cells
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