Ryan W. Nelson

Ryan Nelson

Email: nels5471@umn.edu

Entering Class:
 2007

Education:

Washington University
Anthropology and Biology majors
B.A., 2007

University of Minnesota
Ph.D., Microbiology, Immunology and Cancer Biology Graduate Program, 2014

Honors and Awards:

  • University of Minnesota Foundation J. Thomas Livermore Award, 2013
  • University of Minnesota Foundation Veneziale-Steer Award, 2013
  • NIH/NIDDK National Research Service Award for Individual Predoctoral MD/PhD Fellows, 2011-2015

MSTP Student Governance:

  • Student Advisory Committee 2012-2014

Thesis Advisor: Marc Jenkins, Ph.D.

Thesis Research

Recent work has demonstrated that memory CD4+ T cells decay following clearance of some acute bacterial infections. However, this issue has not been addressed for persistent bacterial infections where CD4+ T cells are the protective cell type. During persistent Salmonella infection in mice, CD4+ T cells control pathogen burden by activating infected macrophages and limiting bacteria to the gut draining mesenteric lymph nodes. Using a peptide:MHCII (p:MHCII)-tetramer based enrichment strategy, we track a polyclonal Salmonella p:MHCII-specific CD4+ T cell response to intragastric infection. We have found that Salmonella p:MHCII-specific T cells are maintained at a numerically stable level throughout persistent infection but decay if the infection is cleared. This population consists of highly functional Th1 cells capable of producing IFN-γ and TNF-α upon re-stimulation. These results indicate that localized p:MHCII presentation in the chronically infected mesenteric lymph nodes is the key to maintaining this naturally stable CD4+ T cell response to Salmonella and simultaneously avoiding exhaustion.

Jenkins lab.

Publications (pubmed)

Malhotra D, Linehan JL, Dileepan T, Lee YJ, Purtha WE, Lu JV, Nelson RW, Fife BT, Orr HT, Anderson MS, Hogquist KA, Jenkins MK. Tolerance is established in polyclonal CD4(+) T cells by distinct mechanisms, according to self-peptide expression patterns. Nat Immunol. 2016 Feb;17(2):187-95.

Nelson RW, Rajpal MN, Jenkins MK. The Neonatal CD4+ T Cell Response to a Single Epitope Varies in Genetically Identical Mice. J Immunol. 2015 Sep 1;195(5):2115-21.

Nelson RW, Beisang D, Tubo NJ, Dileepan T, Wiesner DL, Nielsen K, Wüthrich M, Klein BS, Kotov DI, Spanier JA, Fife BT, Moon JJ, Jenkins MK. T Cell Receptor Cross-Reactivity between Similar Foreign and Self Peptides Influences Naive Cell Population Size and Autoimmunity. Immunity. 2015 Jan 20;42(1):95-107. PMCID: PMC4355167

Tubo NJ, Pagán AJ, Taylor JJ, Nelson RW, Linehan JL, Ertelt JM, Huseby ES, Way SS, Jenkins MK. Single naive CD4+ T cells from a diverse repertoire produce different effector cell types during infection. Cell. 2013 May 9;153(4):785-96. PMCID: PMC3766899

Nelson RW*, McLachlan JB, Kurtz JR, Jenkins MK. CD4+ T cell persistence and function after infection are maintained by low-level peptide:MHC class II presentation. J Immunol. 2013 Mar 15;190(6):2828-34. PMCID: PMC3594488 *co-first author

Publications prior to starting the MD/PhD Program:

Bush LA, Nelson RW, Di Cera E. Murine thrombin lacks Na+ activation but retains high catalytic activity J Biol Chem. 2006;281: 7183-7188.