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Pathobiology & Molecular Medicine

Photo of  Rajat Madan, MD, PhD

Rajat Madan, MD, PhD

Clinical Interest

Infectious Disease

Research Interests

The overall research goal of our laboratory is to better understand the cellular and molecular mechanisms by which nutrition, metabolism, and immune responses to infections are fundamentally linked. Leptin is an adipose tissue-secreted cytokine that sits at the intersection of metabolism and immunity. Interestingly obesity is a state of high serum leptin levels, thus leptin by virtue of its multiple physiologic effects is likely to play an important role in directing inflammation in obese patients as well, who represent a rapidly expanding population demographic worldwide. Clostridium difficile is the #1 cause of healthcare-associated diarrhea in the U.S. In our lab, we are investigating the role of leptin receptor polymorphisms and obesity (as measured by Body Mass Index) in affecting disease susceptibility, severity and disease outcomes in patients with C. difficile infection. In parallel, we are using various leptin transgenic mice and diet-induced obese mice to interrogate the mechanism(s) by which leptin signaling impacts the immune response during C. difficile infections. Our studies (using both human clinical samples and mouse models) have the potential to augment the current treatment paradigm for C. difficile with therapies directed at the host immune response.


Infectious Disease
Internal Medicine

  • Bachelor of Medicine, Bachelor or Surgery (M.B.B.S): JLN Medical College
  • Doctoral Degree: University of Cincinnati
  • Residency: The Christ Hospital
  • Fellowship: University of Virginia
Board Certifications & Licenses
  • American Board of Internal Medicine (Infectious Disease) 10/28/2014
  • American Board of Internal Medicine 08/12/2011
Contact Information
  • Medical Sciences Building
  • Room 6105C
  • 231 Albert Sabin Way
  • Cincinnati, Ohio 45267
  • Office 513-558-4704
  • Fax 513-558-2089
  • Email

Peer Reviewed Publications

Jose, Shinsmon; Mukherjee, Anindita; Abhyankar, Mayuresh M; Leng, Lin; Bucala, Richard; Sharma, Divya; Madan, Rajat 2018. Neutralization of macrophage migration inhibitory factor improves host survival after Clostridium difficile infection. Anaerobe, ,

Vargas, Edwin; Apewokin, Senu; Madan, Rajat 2017. Role of the leukocyte response in normal and immunocompromised host after Clostridium difficile infection. Anaerobe, 45 , 101-105

Jose, Shinsmon; Madan, Rajat 2016. Neutrophil-mediated inflammation in the pathogenesis of Clostridium difficile infections. Anaerobe, ,

Madan, Rajat; Petri, William A 2015. Role of obesity and adipose tissue-derived cytokine leptin during Clostridium difficile infection. Anaerobe, 34 , 182-6

Madan, Rajat; Guo, Xiaoti; Naylor, Caitlin; Buonomo, Erica L; Mackay, Donald; Noor, Zannatun; Concannon, Patrick; Scully, Kenneth W; Pramoonjago, Patcharin; Kolling, Glynis L; Warren, Cirle A; Duggal, Priya; Petri, William A 2014. Role of leptin-mediated colonic inflammation in defense against Clostridium difficile colitis. Infection and immunity, 82 1, 341-9

Naylor, Caitlin; Burgess, Stacey; Madan, Rajat; Buonomo, Erica; Razzaq, Khadija; Ralston, Katherine; Petri, William A 2014. Leptin receptor mutation results in defective neutrophil recruitment to the colon during Entamoeba histolytica infection. mBio, 5 6,

Buonomo, Erica L; Madan, Rajat; Pramoonjago, Patcharin; Li, Li; Okusa, Mark D; Petri, William A 2013. Role of interleukin 23 signaling in Clostridium difficile colitis. The Journal of infectious diseases, 208 6, 917-20

Jarrell, Andrew; Kawsky, Jaclyn; Johnson, Tara; Voss, Sasha; Madan, Rajat; Weitkamp, Tina; Wigle, Patricia 2013. An interdisciplinary approach to determine schistosomiasis prevalence and administer praziquantel to school-age children in Tanzania. American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists, 70 21, 1880-2

Madan, Rajat; Jr, William A Petri 2012. Immune responses to Clostridium difficile infection. Trends in molecular medicine, 18 11, 658-66

Denning, Timothy L; Norris, Brian A; Medina-Contreras, Oscar; Manicassamy, Santhakumar; Geem, Duke; Madan, Rajat; Karp, Christopher L; Pulendran, Bali 2011. Functional specializations of intestinal dendritic cell and macrophage subsets that control Th17 and regulatory T cell responses are dependent on the T cell/APC ratio, source of mouse strain, and regional localization. Journal of immunology (Baltimore, Md. : 1950), 187 2, 733-47

Madan, Rajat; Demircik, Filiz; Surianarayanan, Sangeetha; Allen, Jessica L; Divanovic, Senad; Trompette, Aurelien; Yogev, Nir; Gu, Yuanyuan; Khodoun, Marat; Hildeman, David; Boespflug, Nicholas; Fogolin, Mariela B; Gröbe, Lothar; Greweling, Marina; Finkelman, Fred D; Cardin, Rhonda; Mohrs, Markus; Müller, Werner; Waisman, Ari; Roers, Axel; Karp, Christopher L 2009. Nonredundant roles for B cell-derived IL-10 in immune counter-regulation. Journal of immunology (Baltimore, Md. : 1950), 183 4, 2312-20

Murai, Masako; Turovskaya, Olga; Kim, Gisen; Madan, Rajat; Karp, Christopher L; Cheroutre, Hilde; Kronenberg, Mitchell 2009. Interleukin 10 acts on regulatory T cells to maintain expression of the transcription factor Foxp3 and suppressive function in mice with colitis. Nature immunology, 10 11, 1178-84

Perona-Wright, Georgia; Mohrs, Katja; Szaba, Frank M; Kummer, Lawrence W; Madan, Rajat; Karp, Christopher L; Johnson, Lawrence L; Smiley, Stephen T; Mohrs, Markus 2009. Systemic but not local infections elicit immunosuppressive IL-10 production by natural killer cells. Cell host & microbe, 6 6, 503-12

Pot, Caroline; Jin, Hulin; Awasthi, Amit; Liu, Sue Min; Lai, Chen-Yen; Madan, Rajat; Sharpe, Arlene H; Karp, Christopher L; Miaw, Shi-Chuen; Ho, I-Cheng; Kuchroo, Vijay K 2009. Cutting edge: IL-27 induces the transcription factor c-Maf, cytokine IL-21, and the costimulatory receptor ICOS that coordinately act together to promote differentiation of IL-10-producing Tr1 cells. Journal of immunology (Baltimore, Md. : 1950), 183 2, 797-801

Sun, Jie; Madan, Rajat; Karp, Christopher L; Braciale, Thomas J 2009. Effector T cells control lung inflammation during acute influenza virus infection by producing IL-10. Nature medicine, 15 3, 277-84

Trompette, Aurelien; Divanovic, Senad; Visintin, Alberto; Blanchard, Carine; Hegde, Rashmi S; Madan, Rajat; Thorne, Peter S; Wills-Karp, Marsha; Gioannini, Theresa L; Weiss, Jerry P; Karp, Christopher L 2009. Allergenicity resulting from functional mimicry of a Toll-like receptor complex protein. Nature, 457 7229, 585-8

Dragin, Nadine; Shi, Zhanquan; Madan, Rajat; Karp, Christopher L; Sartor, Maureen A; Chen, Chi; Gonzalez, Frank J; Nebert, Daniel W 2008. Phenotype of the Cyp1a1/1a2/1b1-/- triple-knockout mouse. Molecular pharmacology, 73 6, 1844-56

Machado, Fabiana S; Esper, Lísia; Dias, Alexandra; Madan, Rajat; Gu, YuanYuan; Hildeman, David; Serhan, Charles N; Karp, Christopher L; Aliberti, Júlio 2008. Native and aspirin-triggered lipoxins control innate immunity by inducing proteasomal degradation of TRAF6. The Journal of experimental medicine, 205 5, 1077-86

Divanovic, Senad; Trompette, Aurelien; Petiniot, Lisa K; Allen, Jessica L; Flick, Leah M; Belkaid, Yasmine; Madan, Rajat; Haky, Jennifer J; Karp, Christopher L 2007. Regulation of TLR4 signaling and the host interface with pathogens and danger: the role of RP105. Journal of leukocyte biology, 82 2, 265-71

Tripathi, Pulak; Madan, Rajat; Chougnet, Claire; Divanovic, Senad; Ma, Xiaojing; Wahl, Larry M; Gajewski, Thomas; Karp, Christopher L; Hildeman, David A 2006. An adenoviral vector for probing promoter activity in primary immune cells. Journal of immunological methods, 311 1-2, 19-30

Divanovic, Senad; Trompette, Aurelien; Atabani, Sowsan F; Madan, Rajat; Golenbock, Douglas T; Visintin, Alberto; Finberg, Robert W; Tarakhovsky, Alexander; Vogel, Stefanie N; Belkaid, Yasmine; Kurt-Jones, Evelyn A; Karp, Christopher L 2005. Negative regulation of Toll-like receptor 4 signaling by the Toll-like receptor homolog RP105. Nature immunology, 6 6, 571-8

Divanovic, Senad; Trompette, Aurelien; Atabani, Sowsan F; Madan, Rajat; Golenbock, Douglas T; Visintin, Alberto; Finberg, Robert W; Tarakhovsky, Alexander; Vogel, Stefanie N; Belkaid, Yasmine; Kurt-Jones, Evelyn A; Karp, Christopher L 2005. Inhibition of TLR-4/MD-2 signaling by RP105/MD-1. Journal of endotoxin research, 11 6, 363-8