Sanjeev K. Sahni, PhD

Sanjeev K. Sahni, PhD
Professor

Department of Pathology
Faculty Member, Institute for Human Infections and Immunity

Phone: (409) 772-3651
Email: sksahni@utmb.edu

The major research interests currently being pursued in my laboratory are: Endothelial Pathobiology and Host-Pathogen-Vector Interactions during Infection with Obligate Intracellular Bacterial Pathogens.
1. Vascular endothelium is a multifunctional endocrine and paracrine organ involved in the modulation of blood flow and vessel tone, coagulation, and regulation of immune and inflammatory responses. In various diseases, harmful effects of reactive oxygen species (ROS) and perturbed signaling mechanisms play an important role in endothelial dysfunction. Our goal is to elucidate regulatory mechanisms underlying regulation of redox homeostasis, acute and chronic inflammation, and vascular permeability in the host’s vasculature during infection with obligate intracellular bacterial pathogens in Genus Rickettsia to identify new and unique targets for therapeutic interventions. We are also working on deciphering the effects of drugs in clinical use, for example proteasome inhibitors, on the oxidative stress and anti-oxidant defense mechanisms in vascular endothelium.
2. Rickettsia species include obligate intracellular bacteria responsible for spotted fever and typhus syndromes in humans manifesting as debilitating vasculitis. A consummate understanding of the regulation of rickettsial gene expression in the mammalian hosts and transmitting vectors (ticks and fleas) represents a critically important and novel avenues for strategic intervention. From that perspective, we are pursuing an entirely novel theme by cataloging the small RNA repertoires of pathogenic rickettsiae in correlation with the coding transcriptomes and by decoding sRNA functions and modes of action in essential yet context-specific lifecycle modus operandi, including adaptation, transmission, and virulence. Recently, we have initiated concerted, collaborative efforts to identify and characterize bacterial small RNAs in Orientia species causing scrub typhus in humans.
3. Mechanistic target of rapamycin (mTOR) is a key intracellular hub for the convergence of a multitude of signaling pathways regulating critical molecular processes including autophagy, innate immunity, and inflammation. We are investigating the regulation of mTOR complexes C1 (Raptor) and C2 (Rictor) during host cell interactions with virulent and avirulent strains of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever in humans. Since mTOR represents a stable pharmacologic target due to inherent resistance to mutation(s), manipulation of cellular responses under its control using newly developed modulators of mTOR offers an innovative stratagem for their use as novel therapeutics against intracellular pathogens.

PhD	Kanpur University, Kanpur (UP), India	Biochemistry/Chemistry Dissertation Title: ‘Carbohydrate metabolism in malarial parasites and their hosts’.	1991
MS	Lucknow University, Lucknow (UP), India	Biochemistry	1986
BS	Lucknow University, Lucknow (U.P.), India	Zoology, Botany, Chemistry	1984

2014-2016	UTMB Department of Pathology Annual Trainee Research Day: Best Presentation in Research Scientist Category (Presenting author: Dr. Hema P. Narra).
2015	UTMB Institute for Human Infections and Immunity Annual Colloquium: Best Poster Award (Presenting author: Dr. Hema P. Narra).
2016	UTMB Department of Pathology Annual Trainee Research Day: Best Presentation in Post-doctoral Researcher Category (Presenting author: Dr. Imran H. Chowdhury).
2016-2018	UTMB IHII Post-doctoral Fellowship Award (Dr. Imran H. Chowdhury).
2018	UTMB Department of Pathology Annual Trainee Research Day: Best Presentation in Post-doctoral Researcher Category (Presenting author: Dr. Imran H. Chowdhury).

2000 – 2007	Assistant Professor of Medicine (Primary appointment), Vascular Medicine-Hematology-Oncology Unit, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY.
2004 – 2007	Assistant Professor of Microbiology and Immunology (Secondary appointment), Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY.
2004 – 2011	Member: Immunology, Microbiology, and Virology Cluster, University of Rochester School of Medicine and Dentistry, Rochester, NY
2007 – 2011	Associate Professor of Microbiology and Immunology (Primary appointment), Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY.
2011 – 2013	Associate Professor of Microbiology and Immunology (Adjunct faculty appointment), Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY.
2011 – 2019	Associate Professor, Department of Pathology, The University of Texas Medical Branch, Galveston, TX.
2011 –	Faculty Member, Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, TX.
2019 –	Professor, Department of Pathology, The University of Texas Medical Branch, Galveston, TX.

1. Schroeder, C.L.C., Narra, H.P., Rojas, M., Sahni, A., Patel, J., Khanipov, K., Wood, T.G., Fofanov, Y., and Sahni, S.K.: Bacterial small RNAs in the Genus Rickettsia. BMC Genomics 16: 1075 (2015). PubMed ID: 26679185.
2. Schroeder, C.L.C., Narra, H.P., Sahni, A., Rojas, M., Khanipov, K., Patel, J., Shah, R., Fofanov, Y., and Sahni, S.K.: Identification and characterization of small RNAs in Rickettsia prowazekii. Frontiers in Microbiology 7: 859 (2016). PubMed ID: 27375581.
3. Sahni, A., Thomasson, E., Shah, R., and Sahni, S.K.: Bortezomib effects on human microvascular endothelium in vitro. Pharmacology 98: 272-278 (2016). PubMed ID: 27578289.
4. Narra, H.P., Schroeder, C.L.C., Sahni, A., Rojas, M., Khanipov, K., Fofanov, Y., and Sahni, S.K.:Small regulatory RNAs of Rickettsia conorii. Scientific Reports 6: 36278 (2016). PubMed ID: 27834404.
5. Sahni, A., Narra, H.P., Patel, J., and Sahni, S.K.: MicroRNA signature of human microvascular endothelium infected with Rickettsia rickettsii. International Journal of Molecular Sciences 18: pii: E1471. doi: 10.3390/ijms18071471 (2017). PubMed ID: 28698491.
6. Schroeder, C.L.C., Narra, H.P., Sahni, A., Khanipov, K., Patel, J., Fofanov, Y., and Sahni, S.K.: Transcriptional profiling of Rickettsia prowazekii coding and non-coding transcripts during in vitro host-pathogen and vector-pathogen interactions. Ticks and Tick-borne Diseases 8: 827-836 (2017). PubMed ID: 28709615.
7. Sahni, A., Patel, J., Narra, H.P., Schroeder, C.L.C., Walker, D.H., and Sahni, S.K.: Fibroblast growth factor receptor-1 mediates internalization of pathogenic spotted fever rickettsiae into host endothelium. PLoS One 12(8):e0183181 (2017). doi: 10.1371/journal.pone.0183181. PubMed ID: 28806774.
8. Chowdhury, I.H., Narra, H.P., Sahni, A., Khanipov, K., Schroeder, C.L.C., Patel, J., Fofanov, Y., and Sahni, S.K.: Expression profiling of long non-coding RNA splice variants in human microvascular endothelial cells: lipopolysaccharide effects in vitro. Mediators of Inflammation 3427461 (2017). doi: 10.1155/2017/3427461 PubMed ID: 29147069.
9. Alhassan, A., Liu, H. Cerezo, A., Jakkula, L., Nair, A., Winkley, E., Olson, S., Marlow, D., Sahni, A., Narra, H., Sahni, S., Henningson, J., and Ganta, R. Rickettsia rickettsii whole cell antigens offer protection against Rocky Mountain spotted fever in the canine host. Infection and Immunity [In Press] pii: IAI.00628-18. doi: 10.1128/IAI.00628-18 (2018). PubMed ID: 30396898.
10. Sahni, A., Narra, H.P., Patel, J., and Sahni, S.K.: MicroRNA-regulated rickettsial invasion into host endothelium via Fibroblast Growth Factor 2 and its receptor FGFR1 Cells 7: 240. https://doi.org/10.3390/cells7120240 (2018). PubMed ID: 30513762.
11. Chowdhury, I.H., Narra, H.P., Sahni, A., Khanipov, K., Fofanov, Y., and Sahni, S.K.: Enhancer associated long non-coding RNA transcription and gene regulation in experimental models of rickettsial infection. Frontiers in Immunology 9: 3014. doi: 10.3389/fimmu.2018.03014 (2019). PubMed ID: 30687302.
12. Patel, J., Narra, H.P., Sepuru, K.M., Sahni, A., Golla, S.R., Sahni, A., Singh, A., Schroeder, C.L.C., Chowdhury, I.H., and Sahni, S.K.: Evolution, purification, and characterization of RC0497: a peptidoglycan amidase from the prototypical spotted fever species Rickettsia conorii. Biological Chemistry [In Press]. PubMed ID: 31299006.
NIH Biosketch

Sanjeev K. Sahni, PhDProfessor

Sanjeev K. Sahni, PhD
Professor