Identification of unstable regulatory and autoreactive effector T cells that are expanded in patients with FOXP3 mutations

Expanding the spectrum of IPEX: from new clinical findings to novel treatments

PURPOSE OF REVIEW

This review aims to provide an overview of recent research findings regarding immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, focusing on clinical and immunological novelties, as well as emerging treatment strategies, based on the published literature of the last few years.

RECENT FINDINGS

While it is well known that IPEX can present with a wide range of atypical clinical manifestations, new and unique phenotypes continue to emerge, making it essential to maintain a high level of clinical suspicion both at the time of diagnosis and during follow-up. This unpredictability in clinical presentation is further compounded by the lack of a clear genotype-phenotype correlation. A valuable tool for monitoring comes from recent discoveries regarding the epigenetic signature of Tregs, which, by correlating with disease severity, could prove to be a useful biomarker for diagnosis and ongoing management. The use of biological agents is emerging as an alternative to traditional immunosuppression. Additionally, ongoing studies are exploring the feasibility of gene therapy through the introduction of the wild-type FOXP3 into peripheral CD4 + T cells.

SUMMARY

Further research is needed to fully understand the variable clinical presentations of IPEX and optimize tailored therapies, ensuring better management and outcomes for affected individuals.

Infiltrating treg reprogramming in the tumor immune microenvironment and its optimization for immunotherapy

Immunotherapy has shown promising anti-tumor effects across various tumors, yet it encounters challenges from the inhibitory tumor immune microenvironment (TIME). Infiltrating regulatory T cells (Tregs) are important contributors to immunosuppressive TIME, limiting tumor immunosurveillance and blocking effective anti-tumor immune responses. Although depletion or inhibition of systemic Tregs enhances the anti-tumor immunity, autoimmune sequelae have diminished expectations for the approach. Herein, we summarize emerging strategies, specifically targeting tumor-infiltrating (TI)-Tregs, that elevate the capacity of organisms to resist tumors by reprogramming their phenotype. The regulatory mechanisms of Treg reprogramming are also discussed as well as how this knowledge could be utilized to develop novel and effective cancer immunotherapies.

IPEX syndrome from diagnosis to cure, learning along the way

In the past 2 decades, a significant number of studies have been published describing the molecular and clinical aspects of immune dysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome. These studies have refined our knowledge of this rare yet prototypic genetic autoimmune disease, advancing the diagnosis, broadening the clinical spectrum, and improving our understanding of the underlying immunologic mechanisms. Despite these advances, Forkhead box P3 mutations have devastating consequences, and treating patients with IPEX syndrome remains a challenge, even with safer strategies for hematopoietic stem cell transplantation and gene therapy becoming a promising reality. The aim of this review was to highlight novel features of the disease to further advance awareness and improve the diagnosis and treatment of patients with IPEX syndrome.

FOXP3 deficiency, from the mechanisms of the disease to curative strategies

FOXP3 gene is a key transcription factor driving immune tolerance and its deficiency causes immune dysregulation, polyendocrinopathy, enteropathy X-linked syndrome (IPEX), a prototypic primary immune regulatory disorder (PIRD) with defective regulatory T (Treg) cells. Although life-threatening, the increased awareness and early diagnosis have contributed to improved control of the disease. IPEX currently comprises a broad spectrum of clinical autoimmune manifestations from severe early onset organ involvement to moderate, recurrent manifestations. This review focuses on the mechanistic advancements that, since the IPEX discovery in early 2000, have informed the role of the human FOXP3+ Treg cells in controlling peripheral tolerance and shaping the overall immune landscape of IPEX patients and carrier mothers, contributing to defining new treatments.