New Immune Cell Population Could Transform Tuberculosis Vaccine Development

Tuberculosis (TB) remains a significant global health challenge, with over 10 million new cases annually and no highly effective vaccine available to date. Researchers at Stony Brook University, led by Dr. Charles Kyriakos Vorkas, have identified a novel immune cell type that could serve as an innovative target for TB vaccines and immune therapies. Their groundbreaking study, published in Scientific Reports, reveals the role of innate immune cells called Natural Killer (NK) cells, specifically those expressing CD8a on their surface, in responding to TB exposure and infection.

The team conducted their research using blood samples from a high-risk cohort in Port-au-Prince, Haiti, comprised of household contacts of active TB patients. They observed that these CD8a-positive NK cells are responsive during asymptomatic exposure to Mycobacterium tuberculosis, the pathogen responsible for TB. Notably, these NK cells showed a decline in blood levels as infection progresses from latency to active disease, suggesting their involvement in early immune responses.

Dr. Vorkas explained that these cells exhibit a specialized behavior linked to the major histocompatibility complex (MHC) Class I molecule, which is crucial for immune recognition. Their findings suggest that these CD8a+ NK cells could be leveraged in developing new TB vaccines, particularly as they show potential for targeted immune activation. The study further aligns with recent findings on the protective role of CD8α+ lymphocytes, including NK cells, in BCG vaccine efficacy, hinting at a paradigm shift in TB immunotherapy strategies.

Current TB vaccines, such as Bacille-Calmette Guérin (BCG), provide limited protection, especially in adults. Existing experimental vaccines focus on conventional T-cell responses (CD4+ and CD8+ T cells), but these approaches have not met efficacy expectations. The discovery of a regulatory role for NK cells—especially those expressing CD8a—opens possibilities for novel vaccine designs that harness innate immunity. Future research aims to understand how NK cells recognize TB-derived proteins through mechanisms involving Killer Immunoglobulin-like Receptors (KIRs), which could revolutionize vaccine and immune therapy development.

This research underscores the importance of innate immune cells in infectious disease control and offers promising avenues for more effective TB interventions, potentially transforming global efforts to combat this enduring disease.

Source: https://medicalxpress.com/news/2025-05-immune-cell-population-alternative-tuberculosis.html