Constitutive class I-restricted exogenous presentation of self antigens in vivo.

Abstract

SummaryOvalbumin (OVA)-specific CD8 + T cells from the T cell receptor-transgenic line OT-I (OT-I cells) were injected into unirradiated transgenic 1KIP-mOVA mice, which express a membranebound form of OVA (mOVA) in the pancreatic islet [3 cells and the renal proximal tubular cells. OT-I cells accumulated in the draining lymph nodes (LN) of the kidneys and pancreas and in no other LN. They displayed an activated phenotype and a proportion entered cell cycle. Unilateral nephrectomy 7-13 d before inoculation of OT-I ceils into 1KIP-mOVA mice allowed the injected T cells to home only to the regional LN of the remaining kidney (and pancreas), but when the operation was performed 4 h before injecting the T ceils, homing to the LN of the excised kidney was evident. When the bone marrow of RIP-mOVA mice was replaced with one of a major histocompatibility haplotype incapable of presenting OVA to OT-I cells, no homing or activation was detectable. Therefore, OT-I cells were activated by OVA presented by short-lived antigen-presenting cells of bone marrow origin present in the draining LN of OVA-expressing tissue. These results provide the first evidence that tissue-associated "self" antigens can be presented in the context of class I via an exogenous processing pathway. This offers a constitutive mechanism whereby T cells can be primed to antigens that are present in nonlymphoid tissues, which are not normally surveyed by recirculating naive T cells.

Optimising anti‐tumour CD8 T‐cell responses using combinations of immunomodulatory antibodies

“…The adoptive transfer of OT-I cells into RIPmOVA mice is a useful model in which to study functional OVA-specific T-cell responses, the induction of peripheral tolerance and ways in which this tolerance may be overcome. After transfer, OT-I cells home into the pancreatic lymph nodes where cross-presentation of OVA by DC occurs, and they undergo limited proliferation and are then rapidly depleted [25]. Destruction of OVA-expressing pancreatic islet cells (and hence diabetes) only occurs if a large number (45 Â 10 6 ) of OT-I cells are transferred [26] or if the induction of tolerance can be overcome by transferring the cells with an immune adjuvant, such as poly(I:C) or LPS [27].…”

“…RIPmOVA mice were originally generated by Professor W. Heath (Friedrich-Wilhelms-Universität, Bonn) [25] and provided for this study by Professor Chris Kurts (Friedrich-Wilhelm's University, Bonn) and were bred heterozygously and screened by PCR for OVA expression. The B16-F10 melanoma line was obtained from the ATCC.…”

CD11c: Not merely a murine DC marker, but also a useful vaccination target

“…components of vaccines, on MHC class I molecules to CD8 + T cells. This process is termed crosspresentation [2,3], and, in mice, this task is most efficiently performed by conventional CD8a + (=CD24 + ) DC [4,5] (according to the Shortman classification [6]). Signal 2, i.e.…”

Vaccination with liposome–DNA complexes elicits enhanced antitumor immunity

“…43 Briefly, spleen cells were harvested and restimulated in vitro in 24-well plates by pulsing with 1 mM ova8 (SIINFEKL) peptide for 5 days. The cell culture medium was supplemented with 1% concanavalin-Astimulated rat spleen cell supernatants beginning on day 2 in culture.…”

“…For tetramer staining, single-cell suspensions (approximately 5 Â 10 5 to 1 Â 10 6 cells/well of 96-well plates) were incubated for 1.5 h at 371C in 100 ml tissue culture medium with the appropriate tetramer concentration, as determined by staining of positive control ova-TCR Tg OT-1 cells. 43 After incubation with tetramers, cells were incubated with anti-CD8-APC (clone 53-6.7), anti-CD44 FITC (clone IM7; both from Pharmingen, San Diego, CA) and with biotinylated anti-I-A b antibody (clone Y3P), followed by incubation with streptavidin PE-Cy5 conjugate (Pharmingen). For tetramer analysis, at least 200 000-500 000 total events per sample were collected.…”