Late TNFα blockade is associated with systemic immune rewiring without disease control in established experimental...

Recent human studies have identified TNFα as a therapeutically targetable pathway in autoimmune hepatitis (AIH), but the consequences of TNFα blockade may depend on treatment timing and disease context. Whether TNFα neutralization can restore disease control once autoimmune liver inflammation is already established remains unclear. Here, we investigated late TNFα blockade in experimental autoimmune hepatitis (emAIH). Anti-TNFα treatment was initiated after disease establishment, and mice were analyzed at early and late post-treatment time points by integrating serum biochemistry, hepatic inflammatory infiltrate quantification, liver gene expression, flow cytometry, serum proteomics and regulatory immune readouts. Late TNFα blockade did not improve serum ALT or AST levels and did not reduce hepatic inflammatory infiltrate area compared with isotype-treated controls. Nevertheless, anti-TNFα treatment was associated with hepatic transcriptional remodeling, including reduced Acta2 expression and directional changes in Ccl2 and Fgf21 at the early time point. At the later time point, anti-TNFα treatment was associated with increased the frequencies of IFN-γ- and TNFα-producing splenic CD4⁺ T cells, whereas intrahepatic cytokine-producing T-cell frequencies remained largely unchanged. Serum proteomics identified late systemic inflammatory remodeling, including increased CCL2 abundance. In contrast, hepatic Foxp3 expression and absolute hepatic Treg numbers were not increased. Together, these findings indicate that late TNFα blockade in established emAIH remains biologically active but is uncoupled from biochemical improvement and reduced hepatic inflammatory infiltration. The data complement recent human infliximab studies by suggesting that timing and disease context may shape the consequences of TNFα-targeted therapy in AIH.