Kenneth W. Witwer

Kenneth W. Witwer is an associate professor of molecular and comparative pathobiology and neurology at the Johns Hopkins University School of Medicine in Baltimore, Maryland, United States. His laboratory studies extracellular vesicles (EVs), extracellular RNA (exRNA), and retroviruses, including HIV. Witwer has served as Secretary General and Executive Chair of Science and Meetings of the International Society for Extracellular Vesicles (ISEV), has been a scientific advisor to the US Environmental Protection Agency and the US National Institutes of Health, and is an associate editor of the Journal of Extracellular Vesicles.

Witwer's PhD dissertation research under the supervision of Janice E. Clements was on innate immune system responses to Visna virus and simian immunodeficiency virus (SIV) as models of human immunodeficiency virus (HIV), specifically regulation of microRNAs, cytokines, and the promyelocytic leukemia protein (TRIM19). He then completed a postdoctoral research project on miRNAs as biomarkers of HIV disease. In 2011, Witwer joined the faculty at Johns Hopkins, and he assumed a tenure-track position in 2012.

The Witwer laboratory studies the roles of EVs and exRNA in HIV disease of the central nervous system and in other neurodegenerative diseases, such as Alzheimer's and Parkinson's. Another focus of the group is on how inflammatory insults like cigarette smoking affect progression of disease. Beginning in 2013, Witwer examined the hypothesis that RNAs such as miRNAs in dietary substances could regulate endogenous genes in mammals. These studies led him and others to the conclusion that this type of regulation is unlikely to occur in normal physiology. He subsequently served on two Scientific Advisory Panels of the US EPA and addressed the European Food Safety Authority on related questions of environmental exposure to RNA.

Witwer chaired the organizing committee of the ISEV2015 annual meeting (Bethesda, United States). He has since filled several leadership roles with ISEV and organized or co-organized multiple workshops and other meetings on five continents. He is co-Chair with Paul Robbins of the 2020 Gordon Research Conference on EVs. Witwer is an associate editor of the Journal of Extracellular Vesicles and a member of the editorial board of Clinical Chemistry.

Witwer has contributed to scientific standardization and rigor efforts. He was corresponding author in 2013 of the first position paper of the International Society for Extracellular Vesicles, on standardization of isolation and characterization of EVs in RNA studies. With Clotilde Théry, he coordinated the Minimal Information for Studies of Extracellular Vesicles (MISEV2018), a consensus guidelines document for the EV field. An opponent of AIDS denialism, a largely defunct movement that denied the existence of HIV or its role in causing AIDS, he has encouraged high standards in scientific publishing, critiquing predatory publishing and other publishing practices. He has advocated public availability of scientific data.

• 2003-2006 National Science Foundation Graduate Research Fellowship
• 2009 Richard T. Johnson Award, International Society for NeuroVirology
• 2014 CFAR Scholar Award, Johns Hopkins University Center for AIDS Research
• 2017 Catalyst Award, Johns Hopkins University

• Witwer KW, Sarbanes SL, Liu J, Clements JE (2011). "A plasma microRNA signature of acute lentiviral infection: biomarkers of central nervous system disease". AIDS. 13 (25): 2057–67. doi:10.1097/QAD.0b013e32834b95bf. PMC 3703743.
• Witwer KW, Watson AK, Blankson JN, Clements JE (2012). "Relationships of PBMC microRNA expression, plasma viral load, and CD4+ T-cell count in HIV-1-infected elite suppressors and viremic patients". Retrovirology. 9. doi:10.1186/1742-4690-9-5.
• Witwer KW, Buzás EI, Bemis LT, Bora A, Lässer C, Lötvall J, Nolte-'t Hoen EN, Piper MG, Sivaraman S, Skog J, Théry C, Wauben MH, Hochberg F (2013). "Standardization of sample collection, isolation and analysis methods in extracellular vesicle research". J. Extracell. Vesicles. 2: 20360. doi:10.3402/jev.v2i0.20360. PMC 3760646. PMID 24009894.
• Théry C, Witwer KW, Aikawa E,et al. (2018). "Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines". J. Extracell. Vesicles. 7 (1): 1535750. doi:10.1080/20013078.2018.1535750. PMC 6322352. PMID 30637094.
• Witwer KW, Théry C (2019). "Extracellular vesicles or exosomes? On primacy, precision, and popularity influencing a choice of nomenclature". J. Extracell. Vesicles. 8: 1648167.