Marion Pepper, Ph.D.

Marion Pepper, Ph.D.

Assistant Professor, Immunology

Dr. Pepper graduated with a Bachelor's degree in Biology and English from Williams College and received her Ph.D. in Immunology in 2006 from the University of Pennsylvania.  She completed postdoctoral training at the University of Minnesota and joined the Department of Immunology as an Assistant Professor in 2011.

Contact Info

Department of Immunology
University of Washington  
Office E483, Box 358059
750 Republican Street
Seattle WA 98109-8059
Phone: 206-221-8261 or 206-221-5512
Fax: 206-616-4274

Research Areas

  • Adaptive Immune Responses
    Infectious Diseases


Link to Marion Pepper's Laboratory.


Marion Pepper

CD4+ T cells are important mediators of a protective adaptive immune response.  After an immune response is initiated by activation of a naive T cell through its T cell receptor binding a specific peptide: MHC ligand on an antigen presenting cell, CD4+ T cells can differentiate into various functionally defined subsets.  Each of these subsets has its own arsenal of antimicrobial weapons or regulatory functions that are regulated by the expression of one or more master transcription factors.  As an immune response subsides, some of the CD4+ T cells survive to become "memory" T cells with the capacity to fend off pathogens better than their naive counterparts.  In the Pepper lab, we study how CD4+ T cells differentiate into memory cells and how the resulting memory populations function by tracking and manipulating antigen-specific immune responses. Using techniques developed in the Jenkins lab, we use MHC Class II tetramers to identify and phenotype antigen-specific cells through the entire immune response.  We focus on the CD4+ T cell response to various pathogens from vaccine strains of bacteria (attenuated Listeria) to complex parasitic infections (Plasmodium and Toxoplasma).  The overarching aim of the lab is to generate the knowledge necessary to inform better vaccine design.

1.  Pagán AJ, Pepper M, Chu HH, Green JM, Jenkins MK. 2012. CD28 Promotes CD4+ T cell Expansion during infection Independently of its YMNM and PYAP Motifs. Journal of Immunology. 2012 PMID 22896637

2.  Hand TW, Dos Santo LM, Bouladoux N, Molloy MJ, Pagán AJ, Pepper M, Elson CO 3rd and Belkaid Y. 2012. Acute Gastrointenstinal Infection Induces Long-Lived Microbiota-Specific T Cell Responses. Science. 2012 PMID: 22923434

3.  Pepper M, Pagán AJ, Igyártó BZ, Taylor JJ and Jenkins MK. Opposing signals from the Bcl6 transcription factor and the interleukin-2 receptor generate T helper-1 central and effector memory cells. Immunity. 2011 35(4): 583-595. PMID: 22018468.

4.  Pepper M and Marc K. Jenkins. Origins of CD4+ Effector and Central Memory T cells. Nature Immunology. 2011 131(6):467-71

5.  Pepper M, Linehan JL, Pagán AJ, Zell T, Dileepan T, Cleary PP, and Jenkins MK. 2010. Different routes of bacterial infection induce long-lived Th1 memory cells and short-lived Th17 cells. Nature Immunology 2011 (1):83-9. Article of the month. Commentary 11(1):47-9. 

6.  Moon JJ, Chu HH, Hataye J, Pagán AJ, Pepper M, McLachlan JB, Zell T, and Jenkins MK. Tracking epitope-specific T cells. Nature Protocols 2009 4:565-581. 




B.A., Williams College

Ph.D., Immunology, University of Pennsylvania


Graduate Student
Nicole Arroyo,
Akshay Krishnamurty,

Laboratory Staff
Will Hahn, MD, Fellow,
Brian Hondowicz, PhD, Research Scientist, 
Gladys Keitany, PhD, Post-doctoral Fellow,
Karen Kim, Technician,