e the most proximal LN to the site of tumour growth) ex vivo Th

e. the most proximal LN to the site of tumour growth) ex vivo. These cells were markedly enriched in frequency (Fig. 1A) and total numbers (Fig. 1C) in IL-7-driven and not control (Nil)-cultures. It is worth noting that I-Ad/LACK+, CD4+ T cells accumulated in response to IL-7 in spite selleck of a CD4+ T-cell loss during culture time (Fig. 1D). When quantified in independent experiments, the number of LACK (tumour)-specific

cells and in particular of IL-2/IFN-γ-double secreting CD4+ T cells detected in IL-7-driven cultures over control (Nil) cultures was increased by several folds (7.88±0.78 n=8; and 25.3±8.13 n=3, respectively). Memory-like LACK-specific T cells were undetectable in T-dLN of control TS/A tumour-bearing (Fig. 1A and B, lower panels) and tumour-free 16.2β mice (Fig. 2) both ex vivo and after IL-7-driven culture. This indicates that in vivo Ag sensitization is required for the observed in vitro IL-7-driven response. Both in vitro cell division and survival might account for the selective accumulation of LACK-specific lymphocytes in response to IL-7. To analyze proliferation, cells derived from naive (control) and T-dLN, were labeled with CFSE and cultured without (Nil) and with IL-7. In cultures derived from control LN, few CD4+ T cells underwent in vitro cell proliferation in the absence of stimulation (Fig. 2A, Nil), while a fraction of cells with a CFSEdim (i.e.

diminished CFSE content) profile, Selleckchem LBH589 likely undergoing homeostatic-like cell division, was found in IL-7-driven cultures (Fig. 2A, IL-7), as also described previously 26. In the case of cultures derived from T-dLN, a sizeable fraction of CD4+ T cells proliferated in the absence of stimulation (Fig. 2B, Nil, hereafter defined as Interleukin-2 receptor “spontaneous” cell division). LACK-specific IL-2 (not depicted)

and IFN-γ-double secreting cells, identified by intracellular cytokine staining, were mostly found among CFSEdim cells, and selectively enriched after exposure to IL-7 (Fig. 2B, IL-7). Similar results were obtained with highly purified (>97%) CD4+ cell cultures. Although spontaneous cell division was no longer detectable in CD4+ cell cultures (Fig. 2C and D, Nil), suggesting that APC might support the ex vivo expansion of in vivo Ag-sensitized T cells, LACK-specific CFSEdim T cells accumulated in response to IL-7 (Fig. 2D, bottom) to extents comparable to those found in unfractionated T-dLN cultures (compare pie charts in Fig 2B and D). Thus, IL-7-driven in vitro expansion of in vivo Ag-sensitized memory-like T cells accounts, at least in part, for their selective accumulation. We further analyzed IL-7-driven cultures derived from T-dLN of BALB/c mice, which have a physiological polyclonal representation of LACK (tumour)-specific naive CD4+ T cells (∼1/105), and additionally compared IL-7 to other cytokines known to play a pro-survival role in T-cell biology.

Leave a Reply

Your email address will not be published. Required fields are marked *


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>