Bruce Horwitz

Bruce Horwitz, MD, PhD

Senior Associate Physician in Medicine

Associate Professor of Pediatrics, Harvard Medical School

  • Contact: 617-355-6624

  • Fax: 617-730-0335

Medical Services


  • Emergency Medicine


  • Emergency Medicine
  • Medicine


  • Emergency Medicine
To schedule an appointment: Call 617-355-6624

Experience and Education


Medical School

Yale University School of Medicine, 1991

New Haven, CT


Boston Children's Hospital, 1991-1992

Boston, MA


Boston Children's Hospital, 1992-1994

Boston, MA


Boston Children's Hospital, 1994-1996

Boston, MA


  • Pediatrics

  • Pediatric Emergency Medicine


Publications powered by Harvard Catalyst Profiles
  1. Redhu N, Shouval D, Bakthavatchalu V, Wang C, Conaway E, Goettel J, Mack M, Bleich A, Bry L, Fox J, Snapper S, Horwitz B. O-005 YI Microbiota Drives Inflammation by Altering Intestinal Lamina Propria Macrophage Phenotype in a Novel IL10R-Deficient Model of Very Early Onset IBD. Inflamm Bowel Dis. 2016 Mar; 22 Suppl 1:S2-3.
  2. Goettel JA, Biswas S, Lexmond WS, Yeste A, Passerini L, Patel B, Yang S, Sun J, Ouahed J, Shouval DS, McCann KJ, Horwitz BH, Mathis D, Milford EL, Notarangelo LD, Roncarolo MG, Fiebiger E, Marasco WA, Bacchetta R, Quintana FJ, Pai SY, Klein C, Muise AM, Snapper SB. Fatal autoimmunity in mice reconstituted with human hematopoietic stem cells encoding defective FOXP3. Blood. 2015 Jun 18; 125(25):3886-95.
  3. Shouval DS, Biswas A, Goettel JA, McCann K, Conaway E, Redhu NS, Mascanfroni ID, Al Adham Z, Lavoie S, Ibourk M, Nguyen DD, Samsom JN, Escher JC, Somech R, Weiss B, Beier R, Conklin LS, Ebens CL, Santos FG, Ferreira AR, Sherlock M, Bhan AK, Müller W, Mora JR, Quintana FJ, Klein C, Muise AM, Horwitz BH, Snapper SB. Interleukin-10 receptor signaling in innate immune cells regulates mucosal immune tolerance and anti-inflammatory macrophage function. Immunity. 2014 May 15; 40(5):706-19.
  4. Shouval DS, Ouahed J, Biswas A, Goettel JA, Horwitz BH, Klein C, Muise AM, Snapper SB. Interleukin 10 receptor signaling: master regulator of intestinal mucosal homeostasis in mice and humans. Adv Immunol. 2014; 122:177-210.
  5. Poutahidis T, Cappelle K, Levkovich T, Lee CW, Doulberis M, Ge Z, Fox JG, Horwitz BH, Erdman SE. Pathogenic intestinal bacteria enhance prostate cancer development via systemic activation of immune cells in mice. PLoS One. 2013; 8(8):e73933.
  6. Venkatesh D, Ernandez T, Rosetti F, Batal I, Cullere X, Luscinskas FW, Zhang Y, Stavrakis G, García-Cardeña G, Horwitz BH, Mayadas TN. Endothelial TNF receptor 2 induces IRF1 transcription factor-dependent interferon-ß autocrine signaling to promote monocyte recruitment. Immunity. 2013 May 23; 38(5):1025-37.
  7. Nguyen DD, Wurbel MA, Goettel JA, Eston MA, Ahmed OS, Marin R, Boden EK, Villablanca EJ, Paidassi H, Ahuja V, Reinecker HC, Fiebiger E, Lacy-Hulbert A, Horwitz BH, Mora JR, Snapper SB. Wiskott-Aldrich syndrome protein deficiency in innate immune cells leads to mucosal immune dysregulation and colitis in mice. Gastroenterology. 2012 Sep; 143(3):719-29.e1-2.
  8. Zhao X, Ross EJ, Wang Y, Horwitz BH. Nfkb1 inhibits LPS-induced IFN-ß and IL-12 p40 production in macrophages by distinct mechanisms. PLoS One. 2012; 7(3):e32811.
  9. Yang HT, Wang Y, Zhao X, Demissie E, Papoutsopoulou S, Mambole A, O'Garra A, Tomczak MF, Erdman SE, Fox JG, Ley SC, Horwitz BH. NF-?B1 inhibits TLR-induced IFN-ß production in macrophages through TPL-2-dependent ERK activation. J Immunol. 2011 Feb 15; 186(4):1989-96.
  10. Fox JG, Ge Z, Whary MT, Erdman SE, Horwitz BH. Helicobacter hepaticus infection in mice: models for understanding lower bowel inflammation and cancer. Mucosal Immunol. 2011 Jan; 4(1):22-30.
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  12. Erdman SE, Rao VP, Olipitz W, Taylor CL, Jackson EA, Levkovich T, Lee CW, Horwitz BH, Fox JG, Ge Z, Poutahidis T. Unifying roles for regulatory T cells and inflammation in cancer. Int J Cancer. 2010 Apr 1; 126(7):1651-65.
  13. Allister L, Bachur R, Glickman J, Horwitz B. Serum markers in acute appendicitis. J Surg Res. 2011 Jun 1; 168(1):70-5.
  14. Kentsis A, Lin YY, Kurek K, Calicchio M, Wang YY, Monigatti F, Campagne F, Lee R, Horwitz B, Steen H, Bachur R. Discovery and validation of urine markers of acute pediatric appendicitis using high-accuracy mass spectrometry. Ann Emerg Med. 2010 Jan; 55(1):62-70.e4.
  15. Watanabe K, Rao VP, Poutahidis T, Rickman BH, Ohtani M, Xu S, Rogers AB, Ge Z, Horwitz BH, Fujioka T, Erdman SE, Fox JG. Cytotoxic-T-lymphocyte-associated antigen 4 blockade abrogates protection by regulatory T cells in a mouse model of microbially induced innate immune-driven colitis. Infect Immun. 2008 Dec; 76(12):5834-42.
  16. Murphy CG, Glickman JN, Tomczak K, Wang YY, Beggs AH, Shannon MW, Horwitz BH. Acute appendicitis is characterized by a uniform and highly selective pattern of inflammatory gene expression. Mucosal Immunol. 2008 Jul; 1(4):297-308.
  17. Wang Y, Rickman BH, Poutahidis T, Schlieper K, Jackson EA, Erdman SE, Fox JG, Horwitz BH. c-Rel is essential for the development of innate and T cell-induced colitis. J Immunol. 2008 Jun 15; 180(12):8118-25.
  18. Gadjeva M, Wang Y, Horwitz BH. NF-kappaB p50 and p65 subunits control intestinal homeostasis. Eur J Immunol. 2007 Sep; 37(9):2509-17.
  19. Poutahidis T, Haigis KM, Rao VP, Nambiar PR, Taylor CL, Ge Z, Watanabe K, Davidson A, Horwitz BH, Fox JG, Erdman SE. Rapid reversal of interleukin-6-dependent epithelial invasion in a mouse model of microbially induced colon carcinoma. Carcinogenesis. 2007 Dec; 28(12):2614-23.
  20. Horwitz BH. The straw that stirs the drink: insight into the pathogenesis of inflammatory bowel disease revealed through the study of microflora-induced inflammation in genetically modified mice. Inflamm Bowel Dis. 2007 Apr; 13(4):490-500.
  21. Tomczak MF, Erdman SE, Davidson A, Wang YY, Nambiar PR, Rogers AB, Rickman B, Luchetti D, Fox JG, Horwitz BH. Inhibition of Helicobacter hepaticus-induced colitis by IL-10 requires the p50/p105 subunit of NF-kappa B. J Immunol. 2006 Nov 15; 177(10):7332-9.
  22. Rao VP, Poutahidis T, Ge Z, Nambiar PR, Boussahmain C, Wang YY, Horwitz BH, Fox JG, Erdman SE. Innate immune inflammatory response against enteric bacteria Helicobacter hepaticus induces mammary adenocarcinoma in mice. Cancer Res. 2006 Aug 1; 66(15):7395-400.
  23. Tomczak MF, Gadjeva M, Wang YY, Brown K, Maroulakou I, Tsichlis PN, Erdman SE, Fox JG, Horwitz BH. Defective activation of ERK in macrophages lacking the p50/p105 subunit of NF-kappaB is responsible for elevated expression of IL-12 p40 observed after challenge with Helicobacter hepaticus. J Immunol. 2006 Jan 15; 176(2):1244-51.
  24. Rao VP, Poutahidis T, Ge Z, Nambiar PR, Horwitz BH, Fox JG, Erdman SE. Proinflammatory CD4+ CD45RB(hi) lymphocytes promote mammary and intestinal carcinogenesis in Apc(Min/+) mice. Cancer Res. 2006 Jan 1; 66(1):57-61.
  25. Horwitz B. NF-kappa B, an inhibitor of microflora-induced colitis. J Pediatr Gastroenterol Nutr. 2005 Apr; 40 Suppl 1:S22-3.
  26. Gadjeva M, Tomczak MF, Zhang M, Wang YY, Dull K, Rogers AB, Erdman SE, Fox JG, Carroll M, Horwitz BH. A role for NF-kappa B subunits p50 and p65 in the inhibition of lipopolysaccharide-induced shock. J Immunol. 2004 Nov 1; 173(9):5786-93.
  27. Dedeoglu F, Horwitz B, Chaudhuri J, Alt FW, Geha RS. Induction of activation-induced cytidine deaminase gene expression by IL-4 and CD40 ligation is dependent on STAT6 and NFkappaB. Int Immunol. 2004 Mar; 16(3):395-404.
  28. Fox JG, Rogers AB, Whary MT, Ge Z, Taylor NS, Xu S, Horwitz BH, Erdman SE. Gastroenteritis in NF-kappaB-deficient mice is produced with wild-type Camplyobacter jejuni but not with C. jejuni lacking cytolethal distending toxin despite persistent colonization with both strains. Infect Immun. 2004 Feb; 72(2):1116-25.
  29. Liang SC, Latchman YE, Buhlmann JE, Tomczak MF, Horwitz BH, Freeman GJ, Sharpe AH. Regulation of PD-1, PD-L1, and PD-L2 expression during normal and autoimmune responses. Eur J Immunol. 2003 Oct; 33(10):2706-16.
  30. Erdman SE, Rao VP, Poutahidis T, Ihrig MM, Ge Z, Feng Y, Tomczak M, Rogers AB, Horwitz BH, Fox JG. CD4(+)CD25(+) regulatory lymphocytes require interleukin 10 to interrupt colon carcinogenesis in mice. Cancer Res. 2003 Sep 15; 63(18):6042-50.
  31. Tomczak MF, Erdman SE, Poutahidis T, Rogers AB, Holcombe H, Plank B, Fox JG, Horwitz BH. NF-kappa B is required within the innate immune system to inhibit microflora-induced colitis and expression of IL-12 p40. J Immunol. 2003 Aug 1; 171(3):1484-92.
  32. Erdman SE, Poutahidis T, Tomczak M, Rogers AB, Cormier K, Plank B, Horwitz BH, Fox JG. CD4+ CD25+ regulatory T lymphocytes inhibit microbially induced colon cancer in Rag2-deficient mice. Am J Pathol. 2003 Feb; 162(2):691-702.
  33. Alcamo E, Mizgerd JP, Horwitz BH, Bronson R, Beg AA, Scott M, Doerschuk CM, Hynes RO, Baltimore D. Targeted mutation of TNF receptor I rescues the RelA-deficient mouse and reveals a critical role for NF-kappa B in leukocyte recruitment. J Immunol. 2001 Aug 1; 167(3):1592-600.
  34. Horwitz BH, Mizgerd JP, Scott ML, Doerschuk CM. Mechanisms of granulocytosis in the absence of CD18. Blood. 2001 Mar 15; 97(6):1578-83.
  35. Erdman S, Fox JG, Dangler CA, Feldman D, Horwitz BH. Typhlocolitis in NF-kappa B-deficient mice. J Immunol. 2001 Feb 1; 166(3):1443-7.
  36. Cariappa A, Liou HC, Horwitz BH, Pillai S. Nuclear factor kappa B is required for the development of marginal zone B lymphocytes. J Exp Med. 2000 Oct 16; 192(8):1175-82.
  37. Mizgerd JP, Horwitz BH, Quillen HC, Scott ML, Doerschuk CM. Effects of CD18 deficiency on the emigration of murine neutrophils during pneumonia. J Immunol. 1999 Jul 15; 163(2):995-9.
  38. Horwitz BH, Zelazowski P, Shen Y, Wolcott KM, Scott ML, Baltimore D, Snapper CM. The p65 subunit of NF-kappa B is redundant with p50 during B cell proliferative responses, and is required for germline CH transcription and class switching to IgG3. J Immunol. 1999 Feb 15; 162(4):1941-6.
  39. Horwitz BH, Scott ML, Cherry SR, Bronson RT, Baltimore D. Failure of lymphopoiesis after adoptive transfer of NF-kappaB-deficient fetal liver cells. Immunity. 1997 Jun; 6(6):765-72.
To schedule an appointment: Call 617-355-6624


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