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Highlights d Healthy gut contains ILC1s, ILC3s, and ILC3/NKs, but no ILC2s d Blood and tumor ILCs from CRC patients have unique transcriptomic features d Tumor tissue from CRC patients contains a tumor specific ILC1-like subset and ILC2s d SLAMF1 is identified as an anti-tumor biomarker in CRC

Key Points• MEKK3 regulates platelet activation through ERK1/2 and JNK2.• MEKK3 2/2 mice are protected from microthrombosis and myocardial infarct expansion post-MI.MAPKs play important roles in platelet activation. However, the molecular mechanisms by which MAPKs are regulated in platelets remain largely unknown. Real-time polymerase chain reaction and western blot data showed that MEKK3, a key MAP3K family member, was expressed in human and mouse platelets. Then, megakaryocyte/platelet-specific MEKK3-deletion (MEKK3 2/2 ) mice were developed to elucidate the platelet-related function(s) of MEKK3. We found that agonist-induced aggregation and degranulation were reduced in MEKK3 2/2 platelets in vitro. MEKK3 deficiency significantly impaired integrin aIIbb3-mediated inside-out signaling but did not affect the outside-in signaling.At the molecular level, MEKK3 deficiency led to severely impaired activation of extracellular signal-regulated kinases 1/2 (ERK1/2) and c-Jun NH 2 -terminal kinase 2 but not p38 or ERK5. In vivo, MEKK3 2/2 mice showed delayed thrombus formation following FeCl 3 -induced carotid artery injury. Interestingly, the tail bleeding time was normal in MEKK3 2/2 mice. Moreover, MEKK3 2/2 mice had fewer microthrombi, reduced myocardial infarction (MI) size, and improved post-MI heart function in a mouse model of MI.These results suggest that MEKK3 plays important roles in platelet MAPK activation and may be used as a new effective target for antithrombosis and prevention of MI expansion.

Glucose metabolism plays a key role in thymocyte development. The mammalian target of rapamycin complex 2 (mTORC2) is a critical regulator of cell growth and metabolism, but its role in early thymocyte development and metabolism has not been fully studied. We show here that genetic ablation of Sin1, an essential component of mTORC2, in T lineage cells results in severely impaired thymocyte development at the CD4−CD8− double negative (DN) stages but not at the CD4+CD8+ double positive (DP) or later stages. Notably, Sin1-deficient DN thymocytes show markedly reduced proliferation and glycolysis. Importantly, we discover that the M2 isoform of pyruvate kinase (PKM2) is a novel and crucial Sin1 effector in promoting DN thymocyte development and metabolism. At the molecular level, we show that Sin1–mTORC2 controls PKM2 expression through an AKT-dependent PPAR-γ nuclear translocation. Together, our study unravels a novel mTORC2−PPAR-γ−PKM2 pathway in immune-metabolic regulation of early thymocyte development.