Research Focus
Riti Sharan, Ph.D., is an immunologist who studies HIV, latent tuberculosis and potential treatments.
Dr. Sharan seeks to clarify the precise mechanisms of how HIV reactivates latent tuberculosis (TB) and how this causes both diseases to get worse, even when patients are on antiretroviral therapy against HIV. Her long-term goal is to explore an intervention targeting the immune system to control chronic immune activation and reduce latent TB reactivation. This work relies on a macaque model of TB and simian immunodeficiency virus (SIV), the nonhuman primate equivalent of HIV.
HIV and TB act synergistically to magnify the burden of disease with deadly consequences worldwide. People living with HIV are at a high risk of reactivating latent TB infection. The problem has worsened due to the emergence of multi-drug resistant tuberculosis in people living with HIV, leading to significantly higher mortality rates. Chronic immune activation is a key player in the unfolding immune cascade in HIV/TB co-infection that warrants a closer and deeper look.
Dr. Sharan enjoys extending her duties beyond lab work to student outreach, mentoring trainees, representing Texas Biomed at public platforms, and being an active member of Institute committees.
Inside the Lab
The focus of Dr. Sharan’s independent research is on further defining the impact of HIV in reactivating latent tuberculosis infection (LTBI) resulting in worsening of both diseases. The overarching goal is to identify the key correlates of SIV-mediated chronic immune activation before, during and after anti-retroviral therapy (ART) to develop therapeutic interventions for people with both infections. Dr. Sharan’s funding includes:
- NIH K01 award: IL-22 biology in chronic immune activation
- SNPRC Pilot: whole genome sequencing to identify markers of HIV driven LTBI reactivation
- Texas D-CFAR Pilot: conduct state-of-the-art transcriptomics to study persistence of skewed CD4+ T effector memory despite cART here at Texas Biomed.
Mycobacterium tuberculosis (Mtb) is the bacteria that causes TB. Dr. Sharan uses the nonhuman primate model of SIV/Mtb co-infection to investigate:
- the impact of antiretroviral therapy in preventing the HIV-induced reactivation of LTBI
- the mechanisms of immune activation in HIV/TB co-infection
- identify new potential targets for host-directed therapy
The research holds immense translational potential to advance knowledge in the virus-driven LTBI reactivation in HIV/TB co-infected cohorts. Concurrent with the core aims of Texas Biomed scientific programs, her independent research focuses on basic research on viral interactions with the host, and developing animal models to study immune-based interventions.
Dr. Sharan received her Ph.D. in Microbiology from Central Queensland University, Australia in 2011. She received her Master’s in Microbiology with Honors from Panjab University, India in 2007 and Bachelor of Science in Microbiology, Biochemistry and Zoology from Bangalore University, India in 2005. Dr. Sharan joined Texas Biomed in March 2019.
Main Technologies and Methods Used
- Nonhuman primate (NHP) model of SIV/TB co-infection
- Antiretroviral therapy in NHP model of SIV/TB co-infection
- 10x Genomics single cell sequencing platform
- High parameter flow cytometry
- Immunohistochemistry staining of macaque tissues
- Luminex assay for cytokines
- Cytometry by time of flight, CyTOF
- Spatial transcriptomics
- Biocontainment safety level (BSL)-3