How the immune protein IDO weakens defenses in tuberculosis and whether blocking it helps
Official title: Myeloid and lymphoid immunity-specific mechanisms of IDO mediated immunosuppression and its reversal, during TB
Funded at Texas Biomedical Research Institute · NIH-11295984 · Data updated 2026-11-12
This work looks at whether blocking a protein called IDO can help the immune system fight tuberculosis in people and in animal models, including TB/HIV co-infection.
Quick facts
| Grant type | R01 grant |
|---|---|
| Study type | NIH-funded research |
| Funding institution | Texas Biomedical Research Institute NIH-funded |
| Lab location | 1 site (San Antonio, United States) |
| Project start | May 16, 2018 |
| Project end | January 31, 2031 |
| Funding year | 2026 |
| Award (this year) | $989,998 |
| NIH project number | 2R01AI134245-08 |
| Project ID | NIH-11295984 on NIH RePORTER |
Who could benefit from this research
✓Could help
People with active pulmonary tuberculosis, including those with HIV co-infection or drug-resistant TB, would be the most likely candidates for related clinical testing.
✕Less likely to help
People with latent TB, TB limited to non-lung sites, or those who cannot receive immune-modulating treatments may not benefit from this approach.
What this research studies
Researchers use a macaque model that mimics natural TB and TB/HIV co-infection alongside studies of human lung TB granulomas to understand how IDO suppresses immune cells. They block IDO enzymatic activity with an FDA-approved compound that has already shown benefit in macaques and examine how granulomas, T cell location, and bacterial killing change. The team also studies how IDO blockade works together with standard anti-TB drugs and in the setting of HIV co-infection. Outcomes measured include clinical signs, survival, tissue changes in granulomas, and immune and metabolic signaling pathways.
Why it matters
Potential benefit: If successful, this approach could become an add-on therapy that helps antibiotics work better, improves immune control of TB, and reduces disease and death.
How similar studies have gone: Prior work in macaques and analyses of human TB granulomas showed that blocking IDO reshaped granulomas, increased T cell activity, and improved outcomes, so this approach has encouraging preclinical support.
Where this research is happening
-
Texas Biomedical Research Institute
San Antonio, United States Active
Researchers
- Principal investigator: Mehra, Smriti — Texas Biomedical Research Institute
- Study coordinator: Mehra, Smriti
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About this research
- This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
- Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
- For full project details, budget, and progress reports, visit the official NIH RePORTER page.