Mycobacterium tuberculosis Manipulates Host Responses to Promote Survival

Strategic Insights -

Researchers from the Tongji University School of Medicine in Shanghai, China, have made a groundbreaking discovery on how Mycobacterium tuberculosis (Mtb), the bacteria responsible for tuberculosis, manipulates host responses to promote its intracellular survival. According to their study, published in Nature Microbiology, Mtb uses a metabolite called linoleic acid to increase regulatory T cell function, which in turn inhibits macrophage reactive oxygen species production and promotes Mtb survival within macrophages.

The researchers created a genome-wide mutant library to identify the mechanisms by which Mtb survives within host cells. They found that the expression of Mtb Rv1272c, an ATP-binding cassette transporter, increased under hypoxic conditions and promotes Mtb survival in vivo by increasing lecithin import, followed by the production and release of linoleic acid. This linoleic acid, released by infected macrophages, promotes surface trafficking of the immune checkpoint molecule cytotoxic T lymphocyte antigen 4 (CTLA-4) in T cells, thereby inhibiting macrophage reactive oxygen species production and promoting Mtb survival.

Key Takeaways:

  • The study reveals that Mtb uses a metabolite (linoleic acid) to manipulate host responses and promote its intracellular survival.
  • The bacteria creates a genome-wide mutant library to identify the mechanisms by which Mtb survives within host cells.
  • The researchers identified Mtb Rv1272c as a key player in promoting Mtb survival in vivo.
  • Mtb Rv1272c increased under hypoxic conditions and promotes Mtb survival by increasing lecithin import, followed by the production and release of linoleic acid.
  • Linoleic acid released by infected macrophages promotes surface trafficking of CTLA-4 in T cells, inhibiting macrophage reactive oxygen species production.

Statistics:

  • The study was published in Nature Microbiology on October 21, 2025.
  • The researchers created a genome-wide mutant library to identify the mechanisms by which Mtb survives within host cells.
  • Mtb Rv1272c was found to be upregulated under hypoxic conditions, resulting in increased lecithin import and linoleic acid production.
  • Linoleic acid was released by infected macrophages and promoted surface trafficking of CTLA-4 in T cells ( statistics on CTLA-4 surface trafficking unavailable).
  • The study revealed that Mtb manipulates host responses to promote intracellular survival through the use of linoleic acid.

Sources:

  • NewsRx. Researchers from Tongji University School of Medicine Report Recent Findings in Mycobacterium tuberculosis (Mycobacterium tuberculosis-derived linoleic acid increases regulatory T cell function to promote bacterial survival within macrophages). TB & Outbreaks Week. October 21, 2025; p 6908.
  • Nature Microbiology, 2025. Mycobacterium tuberculosis-derived linoleic acid increases regulatory T cell function to promote bacterial survival within macrophages.
  • Tongji University School of Medicine, Shanghai, People's Republic of China.
  • Nature Portfolio, Heidelberger Platz 3, Berlin, 14197, Germany (publisher contact information).