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DBSP Faculty

S. Ansar Ahmed

S. Ansar Ahmed, DVM, PhD

Professor
Immunology
Head, Department of Biomedical Sciences & Pathobiology
 
e-mail: ansrahmd@vt.edu
Capsule Biography (PDF)


Education

1985 Ph.D., School of Veterinary Studies
The Murdoch University, Australia
1978 DVM (B.V.Sc)
University of Agricultural Sciences, Bangalore
1972 B.Sc.
The Bangalore University

Research Interests

  • Inflammatory cytokine signaling in inflammatory murine models - specifically, interferon-gamma and IL-17 role in inflammation and inflammatory disorders
  • Role of immunomodulators (e.g. estrogen) on transcription factors and gene activation events
  • MicroRNA regulation of the immune system in health and disease

Dr. Ahmed's research program has been funded by the NIH & other agencies for more than two decades. The primary research interest in Dr. Ahmed’s laboratory is to better understand molecular aspects of inflammatory proteins (cytokine signaling) and transcription factors involved in inflammation and chronic inflammatory diseases, which afflict millions. An equally important goal is to develop innovative molecular therapies to dampen the damaging cytokine signaling pathways. This is much needed since current therapies (immunosuppressive drugs) have significant side effects. To address this central issue of inflammatory studies, his laboratory employs a variety of wild type, gene knockouts, and transgenic mice. Two different approaches to study inflammation are taken: (1) mice are exposed to a natural immunomodulator (estrogen) and (2) mice that are genetically prone to develop inflammatory autoimmune lupus. We find that treated mice and lupus-prone mice manifest heightened levels and/or response to pro-inflammatory cytokines such as interferon-γ (IFNγ) and interleukin-17 (IL-17). These cytokines while are essential to combat infections, dysregulation or exaggerated secretion/aberrant response can result in severe inflammatory diseases. We have identified key gene signaling transcription factors (cell activation proteins) and are actively designing strategies to modulate these transcription factors in an effort to contain inflammation. Another exciting project in the laboratory is to understand how naturally occurring small RNAs (microRNAs) regulate the immune system of healthy and autoimmune states. These microRNAs are known to suppress gene activation by inhibiting translation or inducing breakdown of messenger RNA. We have identified signature microRNA expression profile in mice exposed to immunomodulator (estrogen) and in genetically-lupus prone mice. Of significance is that select microRNAs can directly downregulate the induction of inflammatory biomolecules. The presence of signature micoRNA expression profile in autoimmune states is of prognostic, diagnostic and therapeutic values.


Professional Experience

2008-present Head, Department of Biomedical Sciences & Pathobiology, VMRCVM, Virginia Tech
2007-2008 Interim Head, Department of Biomedical Sciences & Pathobiology, VMRCVM, Virginia Tech
2002-2007 Director, Center for Molecular Medicine and Infectious Diseases (CMMID) VMRCVM, Virginia Tech
2001-present Professor of Immunology
Department of Biomedical Sciences & Pathobiology
VMRCVM, Virginia Tech

Professional Memberships

  • American Association of Immunologists
  • International Cytokine Society
  • Member of Grant Review Panels

Selected Publications

  1. Dai, R., R. A. Phillips, E. Karpuzoglu, D. Khan, and S. Ansar Ahmed. (2009). Estrogen regulates transcription factors STAT-1 and NF-kappaB to promote inducible nitric oxide synthase and inflammatory responses. Journal of Immunology 183:6998-7005. NIHMS #152991
  2. Karpuzoglu, E., R. A. Phillips, R. Dai, C. Graniello, R. M. Gogal, Jr., and S. Ansar Ahmed. (2009). Signal transducer and activation of transcription (STAT) 4beta, a shorter isoform of interleukin-12-induced STAT4, is preferentially activated by estrogen. Endocrinology 150:1310-1320. PMID: 19233764
  3. Peairs, A., A. Radjavi, S. Davis, L. Li, S. Anasr Ahmed, S. Giri, and C. M. Reilly. (2009). Activation of AMPK inhibits inflammation in MRL/lpr mouse mesangial cells. Clinical Experimental Immunology 156:542-551. PMC Journal-In process
  4. Dai, R., R. A. Phillips, Y. Zhang, D. Khan, O. Crasta, and S. Ansar Ahmed. (2008). Suppression of LPS-induced Interferon-gamma and nitric oxide in splenic lymphocytes by select estrogen-regulated microRNAs: a novel mechanism of immune modulation. Blood 112:4591-4597. PMC2597130
  5. Dai, R., R. A. Phillips, and S. Ansar Ahmed. (2007). Despite inhibition of nuclear localization of NF-kappa B p65, c-Rel, and RelB, 17-beta estradiol up-regulates NF-kappa B signaling in mouse splenocytes: the potential role of Bcl-3. Journal of Immunology 179:1776-1783
  6. Karpuzoglu, E., R. A. Phillips, R. M. Gogal, Jr., and S. Ansar Ahmed. (2007). IFN-gamma-inducing transcription factor, T-bet is upregulated by estrogen in murine splenocytes: Role of IL-27 but not IL-12. Molecular Immunology 44:1819-1825.PMID: 17046061
  7. Lengi, A. J., R. A. Phillips, E. Karpuzoglu, and S. Ansar Ahmed. (2007). Estrogen selectively regulates chemokines in murine splenocytes. Journal of Leukocyte Biology 81:1065-1074.PMID: 17185357
  8. Karpuzoglu, E., J. B. Fenaux, R. A. Phillips, A. J. Lengi, F. Elvinger, and S. Ansar Ahmed. (2006). Estrogen up-regulates inducible nitric oxide synthase, nitric oxide, and cyclooxygenase-2 in splenocytes activated with T cell stimulants: role of interferon-gamma. Endocrinology 147:662-671.PMID: 16293660
  9. Lengi, A. J., R. A. Phillips, E. Karpuzoglu, and S. Ansar Ahmed. (2006). 17beta-estradiol downregulates interferon regulatory factor-1 in murine splenocytes. Journal of Molecular Endocrinology 37:421-432.PMID: 17170083
  10. Reilly, C. M., S. Olgun, D. Goodwin, R. M. Gogal, Jr., A. Santo, J. W. Romesburg, S. Ansar Ahmed, and G. S. Gilkeson. (2006). Interferon regulatory factor-1 gene deletion decreases glomerulonephritis in MRL/lpr mice. European Journal of Immunology 36:1296-1308.PMID: 16541466