The liver, pancreas, and duodenum drain to shared lymph nodes, and a 2025/2026 study from the Esterházy laboratory showed that the tissue of self-antigen origin determines antigen-specific T cell fate: cytosolic antigen in liver or pancreas is immunologically ignored, high-dose secreted hepatic antigen causes clonal deletion of antigen-specific T cells, and secreted pancreatic or intestinal antigen induces peripheral regulatory T cells. The study left its central mechanistic questions open: which cells and molecules (antigen-presenting cell subsets, antigen-presentation pathways, liver stromal signals) execute high-dose hepatic deletional tolerance and bias it toward deletion rather than regulatory T cell induction, and which tissue-intrinsic regenerative and immunological properties make the pancreas markedly more vulnerable than liver and gut to immune-mediated destruction under comparable antigen-specific T cell challenge.

Background

Peripheral tolerance is the set of mechanisms that prevent mature lymphocytes from attacking healthy tissues; three classical outcomes exist for a self-reactive T cell — immunological ignorance (the cell simply does not encounter its antigen productively), clonal deletion (activation-induced cell death of the antigen-specific clones), and regulation (dominance of peripherally induced regulatory T cells, pTregs, which suppress effector responses rather than being killed). Which outcome occurs depends strongly on where and at what abundance the antigen is presented. The liver has long been regarded as a tolerogenic organ: classic studies with transgenic hepatocyte-expressed antigen showed that the level of hepatic antigen expression acts as a threshold that tunes CD8 T cell fate between priming and deletion (Tay et al., PNAS 2014), and tolerogenic antigen presentation by hepatocytes (the main liver epithelial cells), liver sinusoidal endothelial cells (LSECs, the endothelium lining the liver's small blood vessels), and Kupffer cells (the liver's resident macrophages) is well documented for some antigen systems. Separately, the Esterházy group mapped how lymph nodes (LNs, the drain-filtering organs where dendritic cells show antigen to T cells) are shared between organs: compartmentalized gut LN drainage dictates adaptive immune responses (Esterházy et al., Nature 2019), and the pancreas, duodenum, and liver were shown to co-drain to the same murine LNs, where migratory dendritic cells from different organs mix and intestinal inflammation or liver injury reshapes pancreatic autoimmunity (Brown et al., Immunity 2023). Zhou, Wang, Schaffer, Komnick, Brown, Taylor, Fiske, Sheehan, Dermody, Muir, and Esterházy (bioRxiv Dec 2025; published in Cell Reports, May 2026, 45(5):117324) combined these threads by comparing mice expressing the model antigen ovalbumin (OVA) from three tissues (liver, exocrine pancreas, duodenum) in either a cytosolic or a secreted subcellular compartment, and tracking the fate of OVA-specific T cells. They found tissue-specific tolerance mechanisms — immunological ignorance (cytosolic OVA in liver or pancreas, but not gut), high-dose clonal deletion (secreted hepatic OVA), and pTreg induction (secreted pancreatic and intestinal OVA) — and showed that LN co-drainage influenced only the pTreg arm, creating gut-pancreas-liver inflammatory axes in which self-reactive T cells destroyed tissue yet improved control of pancreatic tumors expressing secreted, but not cytosolic, neoantigen. Pancreatic ductal adenocarcinoma (PDAC) is the predominant, highly lethal form of pancreatic cancer. In their own discussion, the authors state that the precise mechanism of the high-dose hepatic deletional tolerance was not defined — the responsible antigen-presenting cell (APC) subsets, antigen-presentation pathways, and liver stromal signals remain to be identified — and that the markedly higher vulnerability of the pancreas, compared with liver and gut, to immune-mediated destruction under comparable T cell challenge requires explanation in terms of tissue-intrinsic regenerative and immunological capacities.

Problem Statement

In the murine co-drained upper digestive system (liver, exocrine pancreas, and duodenum sharing lymph nodes), answer two linked mechanistic questions left open by Zhou et al. (Cell Reports, 2026): (1) identify the cellular and molecular mediators — the specific antigen-presenting cell subsets, antigen-presentation pathways, and liver stromal signals — by which high-dose secreted hepatic self-antigen induces clonal deletion of antigen-specific T cells rather than peripheral regulatory T cell induction, as observed for secreted pancreatic and intestinal self-antigen at comparable expression; and (2) determine the tissue-intrinsic regenerative and immunological properties that account for the markedly greater susceptibility of the pancreas, relative to liver and gut, to immune-mediated destruction under comparable antigen-specific T cell challenge and inflammation. The common objective is to explain how the tissue of self-antigen origin controls T cell fate and, through it, organ-specific disease susceptibility.

References

  1. Yixuan D. Zhou, Peter Wang, Emily Schaffer, Macy R. Komnick, Hailey Brown, Gwen M. Taylor, Kay L. Fiske, Colin Sheehan, Terence S. Dermody, Alexander Muir, Daria Esterházy (2025). Tissue-specific tolerance mechanisms and lymph node co-drainage converge to shape T cell immunity in the upper digestive system and regulate pancreatic cancer progression. bioRxiv preprint. DOI: 10.64898/2025.12.02.691870. https://doi.org/10.64898/2025.12.02.691870
  2. Zhou YD, Wang P, Schaffer E, Komnick MR, Brown H, Taylor GM, Fiske KL, Sheehan C, Dermody TS, Muir A, Esterházy D (2026). Tissue-specific tolerance mechanisms and lymph node co-drainage shape T cell immunity in the upper digestive system and pancreatic cancer progression. Cell Reports 45(5):117324. DOI: 10.1016/j.celrep.2026.117324. PMID: 42090287. https://pubmed.ncbi.nlm.nih.gov/42090287/
  3. Brown H, Komnick MR, Brigleb PH, Dermody TS, Esterházy D (2023). Lymph node sharing between pancreas, gut, and liver leads to immune crosstalk and regulation of pancreatic autoimmunity. Immunity 56(9):2070-2085. DOI: 10.1016/j.immuni.2023.07.008. PMID: 37557168. https://pubmed.ncbi.nlm.nih.gov/37557168/
  4. Esterházy D, Canesso MCC, Mesin L, Muller PA, de Castro TBR, Lockhart A, ElJalby M, Faria AMC, Mucida D (2019). Compartmentalized gut lymph node drainage dictates adaptive immune responses. Nature 569(7754):126-130. DOI: 10.1038/s41586-019-1125-3. PMID: 30988509. https://pubmed.ncbi.nlm.nih.gov/30988509/
  5. Tay SS, Wong YC, McDonald DM, Wood NA, Roediger B, Sierro F, McGuffog C, Alexander IE, Bishop GA, Gamble JR, Weninger W, McCaughan GW, Bertolino P, Bowen DG (2014). Antigen expression level threshold tunes the fate of CD8 T cells during primary hepatic immune responses. Proceedings of the National Academy of Sciences USA 111(25):E2540-E2549. DOI: 10.1073/pnas.1406674111. PMID: 24927525. https://pubmed.ncbi.nlm.nih.gov/24927525/