Kenneth W. Witwer, PhD

Kenneth W. Witwer, PhD

Associate Professor

Edward D. Miller Research Building
733 N. Broadway
Room 829




Pennsylvania State University, State College, PA
Johns Hopkins University School of Medicine, Baltimore, MD



Dr. Kenneth W. Witwer is an assistant professor of molecular and comparative pathobiology at the Johns Hopkins University School of Medicine. His research focuses on extracellular vesicles, RNA-mediated regulation, biomarker discovery, and therapeutic modulation of innate and intrinsic defenses.

He received his undergraduate degree from Penn State University, where he studied biochemistry and molecular biology, German, and international politics. He earned a doctorate from the Biochemistry, Cellular and Molecular Biology Program at Johns Hopkins and received a National Science Foundation Graduate Research Fellowship. Dr. Witwer remained at Johns Hopkins to complete a postdoctoral fellowship in microRNA biomarker research, and he joined the faculty in 2011.


Current Research

Dr. Witwer investigates extracellular vesicles and RNA in human disease, including HIV infection and inflammatory disease. Ribonucleic acid (RNA) molecules are found not only inside, but also outside of human cells in biological fluids such as blood plasma, urine, and cerebrospinal fluid. Although quite labile, these molecules are protected from degradation by molecular shuttles including extracellular vesicles (EV). Rapidly expanding research programs over the last several years indicate that EVs and their nucleic acid cargo may provide early warning of disease, contribute to the defense against disease, and serve as models for effective therapies. Dr. Witwer is also interested in extracellular RNA as a potential therapeutic approach.



NIH-funded projects

"Extracellular Vesicle-Mediated Immunomodulation in HIV Infection and Nicotine Abuse"

"Development of miRNA-based therapies to silence or purge the latent macrophage reservoir in HAND"

"Biomarkers of the HIV-associated neurocognitive disorders: plasma and CSF miRNAs in prediction, diagnosis and pathogenesis of HAND" (in collaboration with Dr. Janice Clements)

"Circulating cellular and extracellular noncoding RNAs in HIV-1 Elite Suppression" (in collaboration with Dr. Joel Blankson)


Research Opportunities

Rotation projects are available to Cellular and Molecular Medicine students. Local undergraduates with laboratory experience and a strong interest in HIV, RNA, or extracellular vesicle research are encouraged to inquire about available projects. Undergraduates in the Witwer lab have co-authored numerous publications and have earned:

Four young investigator awards from professional meetings;

One Dean's Undergraduate Research Award (DURA);

Five Provost's Undergraduate Research Awards (PURA);

Four Center for AIDS Research Baltimore HIV Scholars; and

A Second Decade Society scholarship.


Graduate Program Affiliation

Dr. Witwer is a faculty member of the Cellular and Molecular Medicine graduate program.


Selected Publications

  1. EV-TRACK Consortium, Van Deun J, Mestdagh P, et al. EV-TRACK: transparent reporting and centralizing knowledge in extracellular vesicle research. Nat Methods. 2017 Feb 28;14(3):228-232.
  2. Kim V, Mears BM, Powell BH, Witwer KW.Mutant Cas9-transcriptional activator activates HIV-1 in U1 cells in the presence and absence of LTR-specific guide RNAs.Matters (Zur). 2017;2017. doi: 10.19185/matters.201611000027.
  3. Han PA, Kim HS, Cho S, Fazeli R, Najafian A, Khawaja H, McAlexander M, Dy B, Sorensen M, Aronova A, Sebo TJ, Giordano TJ, Fahey TJ 3rd, Thompson GB, Gauger PG, Somervell H, Bishop JA, Eshleman JR, Schneider EB, Witwer KW, Umbricht CB, Zeiger MA.. Association of BRAF V600E Mutation and MicroRNA Expression with Central Lymph Node Metastases in Papillary Thyroid Cancer: A Prospective Study from Four Endocrine Surgery Centers. Thyroid. 2016 Apr;26(4):532-42.
  4. Eitan E, Hutchison ER, Marosi K, Comotto J, Mustapic M, Nigam SM, Suire C, Maharana C, Jicha GA, Liu D, Machairaki V, Witwer KW, Kapogiannis D, Mattson MP.Extracellular Vesicle-Associated Aβ Mediates Trans-Neuronal Bioenergetic and Ca2+-Handling Deficits in Alzheimer's Disease Models.NPJ Aging Mech Dis. 2016;2. pii: 16019.
  5. Buchanan EL, Espinoza DA, McAlexander MA, Myers SL, Moyer A, Witwer KW. SAMHD1 transcript upregulation during SIV infection of the central nervous system does not associate with reduced viral load. Sci Rep. 2016 Mar 3;6:22629.

View complete list of publications on PubMed.