Toxoplasma gondii is an intracellular parasite that is found world-wide and is able to infect most warm blooded animals (from birds to humans). In humans and rodents, Toxoplasma naturally establishes a life-long, asymptomatic infection of the brain. Unfortunately, in those with limited immune response (e.g. fetus, organ transplant patients), this tropism for the brain can lead to devastating effects including seizures, blindness, and death. Thus, our goal is to understand the brain-Toxoplasma interaction at the cellular and molecular level so that we can i) develop curative treatment for symptomatic toxoplasmosis and ii) identify new mechanisms for modulating brain immune responses, which are now thought to play a role in neurologic diseases ranging from Multiple Sclerosis to Alzheimer’s disease.
Anita A Koshy, MD
Professor, Neurology
Professor, Immunobiology
Professor, BIO5 Institute
Professor, Evelyn F McKnight Brain Institute
Professor, Neuroscience-GIDP
Professor, Medicine
Professor, Immunobiology
Professor, BIO5 Institute
Professor, Evelyn F McKnight Brain Institute
Professor, Neuroscience-GIDP
Professor, Medicine
2023 Women In Medicine and Science Awardee

Anita Koshy obtained her medical degree from Duke University, where she was an HHMI Medical Student Fellow for 2 years. After obtaining her MD, she did clinical training in Neurology and Infectious Disease, before joining the lab of John Boothroyd at Stanford University for her postdoctoral training. In the Boothroyd lab, she established an in vivo system for permanently marking and tracking host cells that have interacted with parasite Toxoplasma gondii.
Research Interests:
Degrees
- BS: Stanford University
- MD: Duke University
Fellowship
- Infectious Disease Fellowship: Stanford University, 2005-2010
- Postdoctoral Fellowship: Stanford University, 2007-2012
Recent Publications
2025
Massmann, M. D., S. M. Reilly, A. A. Koshy, and J. P. Boyle, "Toxoplasma gondii and the Brain: Frenemies? Or Just Outright Foes?", J Pediatric Infect Dis Soc, vol. 14, issue 8, 2025 Aug 27.
PMCID: PMC12395554 PMID: 40879422
Eberhard, J. N., L. A. Shallberg, A. Winn, S. Chandrasekaran, C. J. Giuliano, E. F. Merritt, E. Willis, C. Konradt, D. A. Christian, D. L. Aldridge, et al., "Immune targeting and host-protective effects of the latent stage of Toxoplasma gondii.", Nat Microbiol, vol. 10, issue 4, pp. 992-1005, 2025 Apr.
PMCID: PMC11964939 PMID: 40148566
Johnson, H. J., J. A. Kochanowsky, S. Chandrasekaran, C. A. Hunter, D. P. Beiting, and A. A. Koshy, "Defining neuronal responses to the neurotropic parasite .", mSphere, vol. 10, issue 6, pp. e0021625, 2025 Jun 25.
PMCID: PMC12188731 PMID: 40444956
Orchanian, S. B., S. Zolog, J. Tomasello, R. Malik, J-H. Shin, A. A. Koshy, and M. B. Lodoen, "parasites induce a localized myeloid cell immune response surrounding parasites in the brain during acute infection.", mBio, vol. 16, issue 7, pp. e0081025, 2025 Jul 09.
PMCID: PMC12239593 PMID: 40492741
2024
Merritt, E. F., J. A. Kochanowsky, P. Hervé, A. A. Watson, and A. A. Koshy, "Toxoplasma type II effector GRA15 has limited influence in vivo.", PLoS One, vol. 19, issue 3, pp. e0300764, 2024.
PMCID: PMC10980211 PMID: 38551902
2023
M Licon, H., C. J. Giuliano, A. W. Chan, S. Chakladar, J. N. Eberhard, L. A. Shallberg, S. Chandrasekaran, B. S. Waldman, A. A. Koshy, C. A. Hunter, et al., "A positive feedback loop controls Toxoplasma chronic differentiation.", Nat Microbiol, vol. 8, issue 5, pp. 889-904, 2023 May.
PMCID: PMC10520893 PMID: 37081202
Kochanowsky, J. A., S. Chandrasekaran, J. R. Sanchez, K. K. Thomas, and A. A. Koshy, "ROP16-mediated activation of STAT6 enhances cyst development of type III Toxoplasma gondii in neurons.", PLoS Pathog, vol. 19, issue 4, pp. e1011347, 2023 Apr.
PMCID: PMC10138205 PMID: 37068104
2020
Patell, R., T. Bogue, P. Bindal, A. Koshy, M. Merrill, W. C. Aird, K. A. Bauer, and J. I. Zwicker, "Incidence of thrombosis and hemorrhage in hospitalized cancer patients with COVID-19.", J Thromb Haemost, 2020 Jul 21.
PMCID: PMC7405046 PMID: 32692862
Johnson, H. J., and A. A. Koshy, "Latent Toxoplasmosis Effects on Rodents and Humans: How Much is Real and How Much is Media Hype?", mBio, vol. 11, issue 2, 2020 03 17.
PMCID: PMC7078474 PMID: 32184245
Patell, R., A. M. Khan, T. Bogue, M. Merrill, A. Koshy, P. Bindal, R. Joyce, W. C. Aird, D. Neuberg, K. A. Bauer, et al., "Heparin induced thrombocytopenia antibodies in Covid-19.", Am J Hematol, 2020 Jul 13.
PMCID: PMC7405086 PMID: 32658337
