Immunometabolic reprogramming of Mycobacterium tuberculosis-responsive memory CD4⁺ T cell subsets is linked to...

Memory CD4⁺ T cells are central to long-term immunity in tuberculosis (TB), yet their functional roles that define their protective capacity remain unclear. Understanding the immune mechanisms that prevent clinical progression from latent TB infection (LTBI) to active TB disease is critical for the development of next-generation vaccines and biomarkers.

We characterized the transcriptomic, metabolic, and functional programs of Mycobacterium tuberculosis (Mtb) antigen-stimulated peripheral CD4⁺ T stem cell (T-SCM), central (T-CM), transitional (T-TM), and effector (T-EM) memory subsets from individuals with remote LTBI. We utilized a multi-platform validation strategy that integrated RNA-sequencing data with protein-level metabolic profiling using "Met-Flow" cytometry and functional growth restriction assays to link memory CD4⁺ T cell differentiation states to immunometabolism and antimycobacterial function. Finally, we evaluated the immunometabolic profiles of memory CD4⁺ T cell subsets in an independent, longitudinal cohort of Mtb-exposed progressors and non-progressors from Brazil (GSE112104).

We identified a differentiation gradient associated with distinct immunometabolic states. T-SCM and T-CM subsets exhibited elevated mitochondrial activity and oxidative metabolism (fatty acid oxidation), supporting their proliferative capacity. In contrast, T-TM and T-EM subsets underwent glycolytic reprogramming and engaged the pentose phosphate pathway, which fueled enhanced cytokine production and Mtb growth restriction. Importantly, we observed that non-progressors exhibit fatty acid oxidation-driven, stem/central memory-like signatures, while progressors and active TB cases display elevated exhaustion markers, glycolytic reprogramming and pro-inflammatory profiles aligned with disease progression.

Collectively, findings from our proof-of-concept study suggest metabolic state as a key axis connecting Mtb antigen-induced memory T cell differentiation, restimulation-induced transcriptional programming, and durability of immune control. The findings provide the basis for future longitudinal studies to examine the dynamic metabolic and functional modulation in Mtb antigen-specific memory T cell subsets from contained infection to disease progression.