Mark Jay Shlomchik, MD, PhD

  • UPMC Endowed and Distinguished Professor, Department of Immunology

Education & Training

  • MD, University of Pennsylvania Medical School, 1989
  • PhD, University of Pennsylvania, 1989
  • BA in Biology, Harvard University, 1981

Research Interests

Our lab is interested in systemic autoimmune diseases, long-lived B cell immunity, and how T cells target organs in autoimmunity and can be targeted to eliminate tumors. Our autoimmunity research uses genetically modified mouse models to address the roles of specific cell types in systemic autoimmunity. Currently we are particularly interested in the identity and function of autoreactive T cells that help autoreactive B cells and that infiltrate target tissues using novel TCR cloning methods. A second major area is investigating the regulatory role of TLR9 and stimulatory role of TLR7 in lupus, and to define how TLRs function in tissue-specific fashion. To this end we have introduced key point mutants and chimeric molecules into the germline of lupus-prone mice to test hypotheses about function in vivo and in signaling assays in vitro. Our B cell immunity work investigates the mechanisms of cellular selection and differentiation in the germinal center (GC), a site of rapid proliferation, mutation, and differentiation into memory B cells (MBC). We are actively working on “non-canonical” extrafollicular B cell responses, which induce isotype switch and mutation outside of GC as well as generate MBC; a key question is what controls the choice between these two types of response. We have also identified novel subsets of MBC in mice and are studying their origins and function using epigenetic, single cell, and subpopulation gene expression analysis. Our work on MBC has now been extended to humans, where, by studying multiple lymphoid and mucosal tissues, we have identified novel populations of MBC.


Elsner RA and Shlomchik MJ. 2019. IL-12 blocks Tfh cell differentiation during Salmonella infection, thereby contributing to germinal center suppression. Cell Reports. 29: 2796-2809 e2795.

Trivedi N, Weisel F, Smita S, Joachim S, Kader M, Radhakrishnan A, Clouser C, Rosenfeld AM, Chikina M, Vigneault F, Hershberg U, Ismail N and Shlomchik MJ. 2019. Liver is a generative site for the B cell response to Ehrlichia muris. Immunity. 51: 1088-1101.

Weisel F, Mullet SJ, Elsner RA, Menk AV, Trivedi N, Luo W, Wikenheiser D, Hawse WF, Chikina M, Smita S, Conter LJ, Joachim SM, Wendell SG, Jurczak MJ, Winkler TH, Delgoffe GM and Shlomchik MJ. 2020. Germinal center B cells selectively oxidize fatty acids for energy while conducting minimal glycolysis. Nat. Immunol. 21: 331-342.

Tilstra JS, John S, Gordon RA, Leibler C, Kashgarian M, Bastacky M, Nickerson KM, and Shlomchik MJ. 2020. B cell-intrinsic TLR9 expression is protective in murine lupus. J. Clin. Inv. 130: 3172-3187.

Weisel, NM, Joachim, SM, Smita, S, Callahan, D, Elsner RA, Conter, LJ, Chikina, M, Farber, DL, Weisel, FJ and Shlomchik, MJ. 2022. Surface phenotypes of naïve and memory B cells in mouse and human tissues. Nature Immunol. 23: 135-145.

Click here for a full list of publications>