Update on Immunology

12/31/12

Disclosures Update on Immunology

• Employer • Medical College of Wisconsin • Research support • National Institutes of Health • $100,000 or more • MCW Dept. of Pediatrics / Children’s Research Institute • Under $5000 • Merck • $50,000 – $100,000 • Organizational interests (other than AAAAI) • ACAAI Mitchell H. Grayson, MD • Deputy Editor of Annals of Allergy, Asthma, and Immunology Associate Professor • Member, Lit. Review, Annual Mtg., Abst. Rev., and Symposia Medical College of Wisconsin Committees Dec 2012

Outline Outline

• Allergy background • Allergy background • Novel T cell subsets • Novel T cell subsets • Th 17 • Th 17 • Nuocytes • Nuocytes • New and upcoming mechanisms • New and upcoming mechanisms • IgE and viral exacerbations of asthma • IgE and viral exacerbations of asthma • Alternatively activated macrophages • Alternatively activated macrophages • Biome • Biome

Pathophysiology of Damage to Allergic Disease epithelium; cellular Outline recruitment ~4 weeks ≤ 15 mins. 4-6 hours + Release: Production of MBP/ECP/EDN • Allergy background Allergen cross- specific IgE Leukotrienes linking IgE • Novel T cell subsets B • Th 17 cell Eosinophil Mast • Nuocytes IL-4 Cell Mediators Th2 IL-6 released: Cells recruited • New and upcoming mechanisms Histamine Th2 Presentation of Basophil allergen Tryptase • IgE and viral exacerbations of asthma Leukotrienes

PGD2 • Alternatively activated macrophages APC IL-4 & other cytokines • Biome Can substitute basophil for mast cell; Specific allergen however, no tryptase or PGD2 release.

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CD4 T cell instruction Th17

• CD4+ T cells • Associated with the immune response to extracellular pathogens • IL-17 is a family of 5 members (A-E) • Is a chemotactic agent for neutrophils • May drive some mucous cell metaplasia • Have been found in human asthma

Cosmi L, et al. Allergy. 2011;66:989.

Th17 cells – can be Th2, too! Outline

• Allergy background • Novel T cell subsets • Th 17 • Nuocytes • New and upcoming mechanisms • IgE and viral exacerbations of asthma • Alternatively activated macrophages • Biome

Cosmi L, et al. Allergy. 2011;66:989.

Nuocytes: Nuocytes Innate Lymphoid Cells type 2 (ILC2)

• Typical lymphocyte morphology Represent a novel • Lack cell surface markers of major hematopoietic immune cell lineages, but do express (innate) that has the ability to • CD25 (IL2Ra) modulate nearly all • CD90 (Thy1) components of the • CD117 (c-Kit) atopic immune • CD127 (IL7Ra) response. • CD278 (ICOS) • ST2 (IL33R) – so IL-33 responsive • IL-17BR – so are IL-25 responsive • Apparent major source of IL-13 • Also can make IL-5, 6, and 9 Scanlon ST, McKenzie ANJ. Curr Opin Immunol. Scanlon ST, McKenzie ANJ. Curr Opin Immunol. 2012;24:707. 2012;24:707.

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Viruses and atopy: Outline Respiratory syncytial virus

• Allergy background 3 years • 80-90% of children 7.5 years • Novel T cell subsets have had RSV at least • Th 17 once within the first 2 years of life • Nuocytes • New and upcoming mechanisms • 0.5-2% of infants • IgE and viral exacerbations of asthma require hospitalization • Especially between 2-6 • Alternatively activated macrophages months of age • Biome Adapted from: Psarras, S, et al. Pediatr Respir Rev. 2004; 5 Suppl. A: S179. Sigurs N. Ped Resp Rev. 2002;3:177-83. Sigurs N. AJRCCM. 2000; 161:1501-7.

Viruses and asthma: Respiratory syncytial virus Timing is everything…..

• Infections in the first year of life tend to be associated with an increased risk of asthma and atopic disease • RSV • Parainfluenza virus – 1 and 3 (PIV-1,3) • Possibly Rhinovirus (hRV) • Infections from 2 years of age onward tend to be associated more with exacerbations of asthma • hRV • PIV-1,3 • Influenza • RSV • Coronovirus, others Adapted from: Sigurs N. Ped Resp Rev. 2002;3:177-83. Sigurs N. AJRCCM. 2000; 161:1501-7. Ann Allergy Asthma Immunol. 2009;103:181-187

Lessons from a mouse model Evidence of IgE against hRV

• hRV39 is a lab strain of hRV that is not present in the wild • Serum from 8 subjects obtained • 5 subjects had history of Allergen specific IgE working with hRV39 • 3 subjects had no known history of working with the virus • hRV39 ELISA used to determine presence of J Exp Med. 2007;204:2759. J Immunol. 2010; 185(9):4983-4987. anti-hRV39 IgE Ann Allergy Asthma Immunol. 2010; 105:437. Jonathan Tam, et al. In preparation.

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Treatment with anti-IgE inhibited Outline seasonal viral asthma exacerbations

• 419 inner city children with persistent allergic asthma for • Allergy background > 1 yr - 6-20 yrs old • Novel T cell subsets • Had to be symptomatic or • Th 17 uncontrolled in 6-12 mos prior to entry • Nuocytes • 4 wk run-in and then New and upcoming mechanisms randomized to omalizumab • In a substudy (n=100), 50% (pbo) – • (208) or placebo (211) 58% (oma) of exacerbations had a • IgE and viral exacerbations of asthma respiratory virus identified (usually hRV) • Virus detection greater with • Alternatively activated macrophages exacerbations (p=0.001) • Biome • No difference in rate of virus detection between the two groups Busse WW, et al. N Engl J Med 2011; 364:11.

M2 macrophages as protective of Function of macrophage subsets lung disease

Modified from: Murray PJ and Wynn TA. Nat Rev Immunol. 2011;11:723. Modified from: Shirey KA, et al. Mucosal Immunol. 2011;3:291.

M2 macrophages associated with Model asthma variability • Bronchoscopy biopsies examined for presence of CD68+ M2 macrophages • Mannose receptor+ or Stabilin-1+ • 16 subjects with asthma • FEV1 94% (65-114) median (range) • 9 subjects without asthma • FEV1 110% (85-121) • Biopsy results correlated with PEF variability

Modiﬁed from: Holtzman MJ, et al. Adv Immunol. 2009;102:245-276. Melgert BN, et al. J Allergy Clin Immunol. 2010;127(3):831.

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Alternatively activated macrophages Outline

• Are found at sites of injury • Allergy background • Are part of the wound healing response • Novel T cell subsets • However, when these cells become • Th 17 chronically activated they have the ability • Nuocytes to drive atopic disease • New and upcoming mechanisms • Chronic injury • IgE and viral exacerbations of asthma • Recurrent acute injury • Alternatively activated macrophages • Seasonal allergen exposure, etc. • Biome

The microbiome: what is it, and why do The gastrointestinal tract we care? • We are “supra-organisms” that • Is a critical interface between the individual must co-exist with this complex and the external environment ecosystem • The GI mucosal immune system must • 1012 viable bacteria/g large • Prevent and respond to infection bowel content • Contain colonizing bacteria in the lumen • 10 times more bacteria in the • Act as a barrier to bacteria, their gut than the body’s own products, and antigens eukaryotic cells • Maintain the systemic immune system in • genetic content of the biome a low reactive state is 10-100 fold greater than • Allow for nutrient and water absorption the human genome • Composition of the biome has Upper alimentary tract Small intestine Large intestine The Human Microbiome Project significant impact on physiology, Peter J. Turnbaugh, Ruth E. Ley, Micah Hamady, Mouth Claire M. Fraser-Liggett, Rob Knight & Jeffrey I. CCF Rectum immunology, metabolism Gordon Nature 449, 804-810 ©2002

Upper alimentary tract Small intestine Large intestine Mechanisms leading to intestinal Mouth Rectum dysbiosis and disease

Mouth Esophagus Stomach Small Intestine Colon pH 7 pH 5-6 pH 2 pH 5-7 pH 5.5-7 109 cfu/ml 102 cfu/ 104 cfu/ml 104-108 cfu/ 1012 cfu/ml ml ml Streptococci Streptococci Streptococci Bacteroides Bacteroides Prevotella Prevotella Lactobacilli Clostridia Clostridia Gemella Veillonella Prevotella Streptococci Prevotella Veillonella Rothia Enterococci Lactobacilli Prophyromonas Granulicatella H. pylori γ-proteobacteria Eubacteria Enterococci Ruminococci Streptococci Biﬁdobacteria Enterobacteria Enterococci Lactobacilli Peptostrepto- coccus CCF Fusobacteria ©2002 Round JL, Mazmanian SK. Nat Rev Immunol. 2009; 9:313.

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Diversity Dysbiosis and disease

Low diversity High diversity

Round JL, Mazmanian SK. Nat Rev Immunol. Abundance is the same, but the evenness is quite different! 2009; 9:313.

The traditional Summary/Conclusion I Th2 paradigm becomes • The standard Th2 paradigm is no longer (much) more complicated! valid in light of the multiple mechanistic pathways that can drive atopic disease Th17 • New therapies will be directed at these IL-17 multiple pathways, and providers need PMN to be aware of their differences

Modified from: Allen JE, Maizels RM. BIOME Nat Rev Immunol. 2011; 11:375.

Summary/Conclusion II

• Viruses have the ability to exacerbate atopic disease (and maybe cause) • This effect appears to be driven through an IgE mediated pathway • The microbial communities that coexist in/on us have the ability to modulate our immune responses (amongst others) • Future therapies may alter these biomes to promote health and to treat disease