Biology subjects

Achacoso, P.

Publications and source records attributed to Achacoso, P..

3 recordsLinked to original sources

bioRxiv2025

A20 restriction of nitric oxide production restores macrophage bioenergetic balance

Macrophages play critical roles in regulating host responses to microbial pathogens and other forms of tissue stress and can acquire pro-inflammatory or tissue reparative phenotypes. A20, or TNFAIP3, is a potent regulator of innate immune cell functions and is extensively linked to human inflammatory and autoimmune diseases. We now find that A20 is a powerful regulator of both glycolytic and mitochondrial respiration in macrophages. Differentiated macrophages that are acutely rendered A20 deficient exhibit increased glycolytic activity and markedly decreased mitochondrial respiration after LPS stimulation. These cells are unable to repolarize from an M1-like to M2-like phenotype. Compromised mitochondrial oxygen consumption in A20 deficient macrophages is caused by increased nitric oxide production. Inhibition or genetic ablation of inducible nitric oxide synthase (iNOS) restores mitochondrial oxidative phosphorylation and lactate production in these cells. These metabolic perturbations occur independently of exaggerated cytokine production and despite robust production of IL-10. Therefore, A20 prevents Warburg-like aerobic glycolysis and restores macrophage homeostasis.

immunology↗

bioRxiv2025

Base-editing a single missense mutation in A20 enhances CAR-T cell efficacy

T cell exhaustion limits the efficacy of cancer immunotherapies. Here, we performed genome-wide loss-of-function screening in repetitively stimulated human T cells and identified the mulitfunctional ubiquitin-modifying protein A20/TNFAIP3 as a major negative regulator of exhausted T cell persistence. Protein large language modeling, deep base-editing mutagenesis, and studies in immunocompetent mice with domain-specific inactivating mutations revealed A20s non-enzymatic M1 ubiquitin-binding zinc finger 7 (A20ZF7) motif as critical to suppression of anti-tumor immunity. A20ZF7-deficient CD8+ tumor-infiltrating lymphocytes (TILs) resisted terminal exhaustion and circumvented an unappreciated mechanism restraining perforin degranulation in terminally exhausted cells. Human chimeric antigen receptor (CAR)-T cells engineered via base-editing to inactivate A20ZF7 via a single missense mutation also resisted exhaustion, secreted more perforin and robustly suppressed cancer in vivo. These studies pinpoint A20ZF7 as a novel T cell checkpoint and reveal precision base-editing of missense mutations as an effective approach to enhance CAR-T cell therapy.

immunology↗

bioRxiv2021

Microbial signals and lymphotoxin drive TNF-independent death of A20 and ABIN-1 deficient epithelium

Anti-TNF antibodies are effective for treating patients with inflammatory bowel disease (IBD), but many patients fail to respond to anti-TNF therapy, highlighting the importance of TNF-independent disease. We previously demonstrated that acute deletion of two IBD susceptibility genes, A20 (Tnfaip3) and Abin-1 (Tnip1), in intestinal epithelial cells (IECs) sensitizes mice to both TNF-dependent and TNF-independent death. Here we show that TNF-independent IEC death after A20 and Abin-1 deletion is rescued by germ-free derivation or deletion of MyD88, while deletion of Trif provides only partial protection. Combined deletion of Ripk3 and Casp8, which inhibits both apoptotic and necroptotic death, completely protects against death after acute deletion of A20 and Abin-1 in IECs. A20 and Abin-1-deficient IECs are sensitized to TNF-independent, TNFR-1-mediated death in response to lymphotoxin alpha (LT) homotrimers. Blockade of LT in vivo reduces weight loss and improves survival when combined with partial deletion of MyD88. These data show that microbial signals, MyD88, and LT all contribute to TNF-independent intestinal injury. SUMMARYHere we show that germ-free derivation, MyD88 deletion, combined Ripk3 and Casp8 deletion, or anti-LT, all reduce TNF-independent intestinal injury after A20 and Abin-1 deletion.

immunology↗