Autophagy protects tumors from T cell-mediated cytotoxicity via inhibition of TNFα-induced apoptosis.

Although T cell checkpoint inhibitors have transformed the treatment of cancer, the molecular determinants of tumor cell sensitivity to T cell-mediated killing need further elucidation. Here, we describe a mouse genome-scale CRISPR knockout screen that identifies tumor cell TNFα signaling as an important component of T cell-induced apoptosis, with NF-κB signaling and autophagy as major protective mechanisms. Knockout of individual autophagy genes sensitized tumor cells to killing by T cells that were activated via specific TCR or by a CD3 bispecific antibody.

Genome-scale CRISPR activation screen uncovers tumor-intrinsic modulators of CD3 bispecific antibody efficacy.

Bispecific antibodies (bsAb) that bridge tumor cells and CD3-positive effector T cells are being developed against many tumor cell targets. While tumor cell factors other than target expression level appear to play a role in determining the efficacy of CD3 bsAb, the identity of such factors remains largely unknown. Using a co-culture system of primary human T cells and B lymphoma cell lines, we demonstrate a range of sensitivities to CD20xCD3 bsAb that is independent of CD20 surface expression.

Angiopoietins bind thrombomodulin and inhibit its function as a thrombin cofactor.

Angiopoietin-1 (Ang1) and Angiopoietin-2 (Ang2) are ligands for Tie2, an endothelial-specific receptor tyrosine kinase that is an essential regulator of angiogenesis. Here we report the identification, via expression cloning, of thrombomodulin (TM) as another receptor for Ang1 and Ang2. Thrombomodulin is an endothelial cell surface molecule that plays an essential role as a coagulation inhibitor via its function as a cofactor in the thrombin-mediated activation of protein C, an anticoagulant protein, as well as thrombin-activatable fibrinolysis inhibitor (TAFI).

Angiopoietin-2 functions as a Tie2 agonist in tumor models, where it limits the effects of VEGF inhibition.

The angiopoietins Ang1 (ANGPT1) and Ang2 (ANGPT2) are secreted factors that bind to the endothelial cell-specific receptor tyrosine kinase Tie2 (TEK) and regulate angiogenesis. Ang1 activates Tie2 to promote blood vessel maturation and stabilization. In contrast, Ang2, which is highly expressed by tumor endothelial cells, is thought to inhibit Tie2 activity and destabilize blood vessels, thereby facilitating VEGF-dependent vessel growth.

Dexamethasone treatment and ICAM-1 deficiency impair VEGF-induced angiogenesis in adult brain.

Background: Infusion of exogenous vascular endothelial growth factor (VEGF) into adult brain at doses above 60 ng/day induces dramatic angiogenesis accompanied by vascular leak and inflammation. Blood vessels formed by this treatment are dilated and tortuous, exhibiting a pathological morphology. Pathological VEGF-induced angiogenesis is preceded by vascular leak and inflammation, which have been proposed to mediate subsequent angiogenesis.

Angiopoietin-2 functions as an autocrine protective factor in stressed endothelial cells.

Angiopoietin (Ang)-2, a context-dependent agonist/antagonist for the vascular-specific Tie2 receptor, is highly expressed by endothelial cells at sites of normal and pathologic angiogenesis. One prevailing model suggests that in these settings, Ang-2 acts as an autocrine Tie2 blocker, inhibiting the stabilizing influence of the Tie2 activator Ang-1, thereby promoting vascular remodeling. However, the effects of endogenous Ang-2 on cells that are actively producing it have not been studied in detail.

Expression of Ciliary Neurotrophic Factor and the Neurotrophins-Nerve Growth Factor, Brain-Derived Neurotrophic Factor and Neurotrophin 3-in Cultured Rat Hippocampal Astrocytes.

Cultured astrocytes are known to possess a range of neurotrophic activities in culture. In order to examine which factors may be responsible for these activities, we have examined the expression of the genes for four known neurotrophic factors-ciliary neurotrophic factor (CNTF), nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3)-in purified astrocyte cultures derived from neonatal rat hippocampus. Hippocampal astrocytes were found to express mRNA for three neurotrophic factors-CNTF, NGF and NT3-at significantly higher levels than other cultured cell types or cell lines examined.