PTPMT1-dependent regulatory T cells mediate immunological tolerance to gut pathobionts

Meanwhile, pathobiont infections, such as those caused by Helicobacter species, affect nearly half the global population, with symptoms manifesting in only 20%, adding a new layer of complexity. The genetic and environmental factors that disrupt gut tolerogenic mechanisms, tipping the balance toward disease in symptomatic infections, are not fully understood.

Here, we show that PTPMT1 impairs tolerance to Helicobacter via Treg cells, independently from T cell-generated Type I or Type II interferons. Without cardiolipin, Treg cells lose metabolic fitness and immunosuppressive potential, unleashing pro-inflammatory myeloid cells in the gut. As a result, PTPMT1 ΔT mice are highly vulnerable to pathobiont infections even without microbiome imbalance.