CD4 T cells found to be key players in tuberculosis defense

The body's first line of defense against tuberculosis (TB) involves immune cells that suppress lung inflammation instead of activating it, reported University of Pittsburgh and the Ragon Institute of Mass General, MIT, and Harvard scientists today in Immunity . The research showed that a subset of infection-fighting white blood cells, called CD4 T cells , protect the lungs from reinfection by creating an anti-inflammatory environment within the lung tissue, rather than secreting molecules that directly kill invading Mycobacterium tuberculosis, or Mtb, bacteria that cause TB. The unexpected discovery complements previous research about the role of protective immune T cells in controlling TB infection and points at ways to improve existing tuberculosis vaccines.

Our study suggests that a vaccine that induces the 'right' kind of CD4 T cells that limit inflammation quickly upon infection may be key to providing long lasting immunity." JoAnne Flynn, Ph.D.

, senior and corresponding author, distinguished professor and chair of microbiology and molecular genetics at Pitt Despite TB being all but eradicated in the United States, an estimated 10.6 million people globally fell ill with the disease in 2022. TB remains especially prevalent and deadly in Southeast Asia, Africa and the Western Pacific, where outbreaks occur regularly and people often get exposed to Mtb multiple times, even after the initial infection was cured.

Mtb infection is often accompanied by symptoms such as persiste.