Bruce Horwitz, MD, PhD
Senior Associate Physician in Pediatrics, Division of Emergency Medicine
Associate Professor of Pediatrics, Harvard Medical School
Image
Bruce Horwitz, MD, PhD
Senior Associate Physician in Pediatrics, Division of Emergency Medicine
Associate Professor of Pediatrics, Harvard Medical School
Medical Services
Languages
English
Education
Medical School
Yale University School of Medicine
1991
New Haven
CT
Internship
Boston Children's Hospital
1991
Boston
MA
Residency
Boston Children's Hospital
1994
Boston
MA
Fellowship
Boston Children's Hospital
1996
Boston
MA
Certifications
American Board of Pediatrics (General)
American Board of Pediatrics (Emergency Medicine)
Publications
Enhanced Production of Lipid Mediators in Plasma and Activation of DNA Damage Pathways in PBMCs Are Correlated With the Severity of Ancestral SARS-CoV-2 Infection. View Abstract
Variants and vaccines impact nasal immunity over three waves of SARS-CoV-2. View Abstract
COVID-19 mRNA Vaccines Induce Robust Levels of IgG but Limited Amounts of IgA Within the Oronasopharynx of Young Children. View Abstract
Bacterial Sphingolipids Exacerbate Colitis by Inhibiting ILC3-derived IL-22 Production. View Abstract
An enhanced IL17 and muted type I interferon nasal epithelial cell state characterizes severe COVID-19 with fungal coinfection. View Abstract
COVID-19 mRNA vaccines induce robust levels of IgG but limited amounts of IgA within the oronasopharynx of young children. View Abstract
Humoral profiles of toddlers and young children following SARS-CoV-2 mRNA vaccination. View Abstract
Enhanced production of eicosanoids in plasma and activation of DNA damage pathways in PBMCs are correlated with the severity of ancestral COVID-19 infection. View Abstract
Humoral profiles of toddlers and young children following SARS-CoV-2 mRNA vaccination. View Abstract
The IL-10 receptor inhibits cell extrinsic signals necessary for STAT1-dependent macrophage accumulation during colitis. View Abstract
Severe COVID-19 is associated with fungal colonization of the nasopharynx and potent induction of IL-17 responses in the nasal epithelium. View Abstract
Monocytes transition to macrophages within the inflamed vasculature via monocyte CCR2 and endothelial TNFR2. View Abstract
CCR2 promotes monocyte recruitment and intestinal inflammation in mice lacking the interleukin-10 receptor. View Abstract
Variants in STXBP3 are Associated with Very Early Onset Inflammatory Bowel Disease, Bilateral Sensorineural Hearing Loss and Immune Dysregulation. View Abstract
Utilizing a reductionist model to study host-microbe interactions in intestinal inflammation. View Abstract
Increased ACE2 Levels and Mortality Risk of Patients With COVID-19 on Proton Pump Inhibitor Therapy. View Abstract
Impaired local intrinsic immunity to SARS-CoV-2 infection in severe COVID-19. View Abstract
Impaired local intrinsic immunity to SARS-CoV-2 infection in severe COVID-19. View Abstract
Characterizing T cell subsets in the nasal mucosa of children with acute respiratory symptoms. View Abstract
Single-Cell Analyses of Colon and Blood Reveal Distinct Immune Cell Signatures of Ulcerative Colitis and Crohn's Disease. View Abstract
Effects of Colonization of Gnotobiotic Swiss Webster Mice with Helicobacter bilis. View Abstract
Generation of protective pneumococcal-specific nasal resident memory CD4+ T cells via parenteral immunization. View Abstract
Alpha kinase 1 controls intestinal inflammation by suppressing the IL-12/Th1 axis. View Abstract
WASP-mediated regulation of anti-inflammatory macrophages is IL-10 dependent and is critical for intestinal homeostasis. View Abstract
Macrophage dysfunction initiates colitis during weaning of infant mice lacking the interleukin-10 receptor. View Abstract
Inhibition of Inflammatory Gene Transcription by IL-10 Is Associated with Rapid Suppression of Lipopolysaccharide-Induced Enhancer Activation. View Abstract
Interleukin-22 drives nitric oxide-dependent DNA damage and dysplasia in a murine model of colitis-associated cancer. View Abstract
Interleukin 1ß Mediates Intestinal Inflammation in Mice and Patients With Interleukin 10 Receptor Deficiency. View Abstract
O-005 YI Microbiota Drives Inflammation by Altering Intestinal Lamina Propria Macrophage Phenotype in a Novel IL10R-Deficient Model of Very Early Onset IBD. View Abstract
Fatal autoimmunity in mice reconstituted with human hematopoietic stem cells encoding defective FOXP3. View Abstract
Interleukin-10 receptor signaling in innate immune cells regulates mucosal immune tolerance and anti-inflammatory macrophage function. View Abstract
Interleukin 10 receptor signaling: master regulator of intestinal mucosal homeostasis in mice and humans. View Abstract
Pathogenic intestinal bacteria enhance prostate cancer development via systemic activation of immune cells in mice. View Abstract
Endothelial TNF receptor 2 induces IRF1 transcription factor-dependent interferon-ß autocrine signaling to promote monocyte recruitment. View Abstract
Wiskott-Aldrich syndrome protein deficiency in innate immune cells leads to mucosal immune dysregulation and colitis in mice. View Abstract
Nfkb1 inhibits LPS-induced IFN-ß and IL-12 p40 production in macrophages by distinct mechanisms. View Abstract
NF-?B1 inhibits TLR-induced IFN-ß production in macrophages through TPL-2-dependent ERK activation. View Abstract
Helicobacter hepaticus infection in mice: models for understanding lower bowel inflammation and cancer. View Abstract
Unifying roles for regulatory T cells and inflammation in cancer. View Abstract
Serum markers in acute appendicitis. View Abstract
Discovery and validation of urine markers of acute pediatric appendicitis using high-accuracy mass spectrometry. View Abstract
Cytotoxic-T-lymphocyte-associated antigen 4 blockade abrogates protection by regulatory T cells in a mouse model of microbially induced innate immune-driven colitis. View Abstract
Acute appendicitis is characterized by a uniform and highly selective pattern of inflammatory gene expression. View Abstract
c-Rel is essential for the development of innate and T cell-induced colitis. View Abstract
NF-kappaB p50 and p65 subunits control intestinal homeostasis. View Abstract
Rapid reversal of interleukin-6-dependent epithelial invasion in a mouse model of microbially induced colon carcinoma. View Abstract
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. View Abstract
Inhibition of Helicobacter hepaticus-induced colitis by IL-10 requires the p50/p105 subunit of NF-kappa B. View Abstract
Innate immune inflammatory response against enteric bacteria Helicobacter hepaticus induces mammary adenocarcinoma in mice. View Abstract
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. View Abstract
Proinflammatory CD4+ CD45RB(hi) lymphocytes promote mammary and intestinal carcinogenesis in Apc(Min/+) mice. View Abstract
NF-kappa B, an inhibitor of microflora-induced colitis. View Abstract
A role for NF-kappa B subunits p50 and p65 in the inhibition of lipopolysaccharide-induced shock. View Abstract
Induction of activation-induced cytidine deaminase gene expression by IL-4 and CD40 ligation is dependent on STAT6 and NFkappaB. View Abstract
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. View Abstract
Regulation of PD-1, PD-L1, and PD-L2 expression during normal and autoimmune responses. View Abstract
CD4(+)CD25(+) regulatory lymphocytes require interleukin 10 to interrupt colon carcinogenesis in mice. View Abstract
NF-kappa B is required within the innate immune system to inhibit microflora-induced colitis and expression of IL-12 p40. View Abstract
CD4+ CD25+ regulatory T lymphocytes inhibit microbially induced colon cancer in Rag2-deficient mice. View Abstract
Targeted mutation of TNF receptor I rescues the RelA-deficient mouse and reveals a critical role for NF-kappa B in leukocyte recruitment. View Abstract
Mechanisms of granulocytosis in the absence of CD18. View Abstract
Typhlocolitis in NF-kappa B-deficient mice. View Abstract
Nuclear factor kappa B is required for the development of marginal zone B lymphocytes. View Abstract
Effects of CD18 deficiency on the emigration of murine neutrophils during pneumonia. View Abstract
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. View Abstract
Failure of lymphopoiesis after adoptive transfer of NF-kappaB-deficient fetal liver cells. View Abstract
Inverse relationship of peripheral thyrotropin-stimulating hormone levels to brain activity in mood disorders. View Abstract
Brain activity during transient sadness and happiness in healthy women. View Abstract
Regional brain activity when selecting a response despite interference: An H2 (15) O PET study of the stroop and an emotional stroop. View Abstract
Bovine papillomavirus E2 gene regulates expression of the viral E5 transforming gene. View Abstract