How T cells combat tuberculosis


Tuberculosis (TB) remains a major global health threat, claiming over 1.3 million lives annually. While existing vaccines like BCG offer some protection, they’re not fool proof. But there may be hope. A recent study uncovered new insights into how our immune system fights TB (Figure 1).

This research highlights the critical role of T cells, our body’s specialized soldiers. These cells don’t attack the bacteria but target specific markers called epitopes. Understanding these epitopes is crucial for developing better vaccines and treatments.

Figure 1: Breadth and dominance of epitopes in mid-treatment ATB participants. A Number of epitopes recognized by each participant. Each dot is one participant, n = 21; median ± interquartile range is shown. B Distribution of recognized epitopes by the number of participants recognizing each epitope. C Epitopes ranked based on the magnitude of response (solid line – % of total response, dotted line – total spot forming cells (SFC)). Black dotted lines indicate the top 55 epitopes. Source data are provided as a Source data file.

The study analysed T cells from patients across three continents, capturing a wide range of genetic and environmental factors influencing immune responses. This global approach led to the discovery of 137 unique T cell epitopes, with some being recognized by immune systems across different populations. The study also compared T cell activity in active TB patients with healthy individuals. Remarkably, researchers identified distinctive patterns in T cell responses, potentially paving the way for a new diagnostic tool. Imagine detecting active TB by simply analysing immune system activity – a significant leap in early diagnosis and treatment.

This research is a significant step forward in our fight against TB. By understanding how T cells recognize and combat the bacteria, we can develop more effective diagnostics, vaccines, and therapies. While further research is needed, these findings offer a beacon of hope in the battle against this global health challenge.

Journal article: Panda, S., et al., 2024. Identification of differentially recognized T cell epitopes in the spectrum of tuberculosis infection. Nature Communications.

Summary by Stefan Botha

International Union of Immunological SocietiesUniversity of South AfricaInstitute of Infectious Disease and Molecular MedicineElizabeth Glazer Pediatric Aids Foundation