Asthmatic Phenotypes in the PhysGen Consomic Rats

1
Asthmatic Phenotypes in the PhysGen Consomic
Rats UW-MCW Collaboration Project Update
L.A. Rosenthal, R.L. Sorkness, and R.F. Lemanske,
Jr.
Morris Institute for Respiratory Research
2
Genetic Factors
Environmental Factors
Atopy (Cytokine Dysregulation)
Respiratory Viruses Allergens
AGE
Asthma Phenotype
3
Post-bronchiolitis Asthma-like Phenotype
aerosolized parainfluenza type 1 (Sendai) virus
weanling rats (3-4 weeks old)
Fischer 344 (F344)
Brown Norway (BN)
low IgE producer nonatopic (Th1)
high IgE producer atopic (Th2)
8-10 weeks postinfection
Normal Airways
Abnormal Airways

• episodic, reversible airway obstruction
• chronic airway inflammation
• airway hyperresponsiveness to methacholine
• airway wall remodeling

Model developed in collaboration with W.L.
Castleman (U. of Florida)
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Genetic Factor
Environmental Factor
AGE
Rat Strain
Sendai Virus
Asthmatic Phenotype
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Development of the Post-bronchiolitis Asthma-like
Phenotype in Brown Norway Rats Host Response
(Genetic Factor) to Sendai Virus (Environmental
Factor) During Early Life (Developmental
Factor) Drives Process
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Acute Phase
Chronic Phase
BN and F344 Bronchiolitis
BN YES F344 NO
Dysregulation of innate immune response?
d6-8
gt Week 4
Sendai Virus Infection
Virus shedding
Abnormal resolution of acute inflammatory changes?

• Development of asthma-like phenotype
• episodic, reversible airway obstruction
• chronic airway inflammation
• airway hyperresponsiveness
• airway wall remodeling

d2
Viral replication
d10-14
Resolution of acute inflammatory changes
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Development of Asthma-like Phenotype Importance
of IFN-g During Acute Phase

• IFN-g in bronchoalveolar lavage fluid during
  acute Sendai virus infection in weanling rats
  F344 gt BN
• Aerosolized IFN-g prevents the development of
  post-bronchiolitis chronic airway dysfunction in
  BN rats.

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Post-bronchiolitis Asthma-like Phenotype
aerosolized parainfluenza type 1 (Sendai) virus
IFN-g
weanling rats (3-4 weeks old)
Fischer 344 (F344)
Brown Norway (BN)
low IgE producer nonatopic (Th1)
high IgE producer atopic (Th2)
8-10 weeks postinfection
Normal Airways
Normal Airways
Sorkness et al. 1999. AJRCCM 160705
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PhysGen Consomic Rats

• Parental strains for consomic rats
• Dahl salt sensitive (SS hypertension model)
• Fawn hooded hypertensive (FHH hypertension and
  end-stage renal disease model)
• Brown Norway (BN control strain normotensive)
• Useful for studying the role of genetic factors
  in susceptibility/resistance to the development
  of the post-bronchiolitis asthma-like phenotype?
  

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Balance Between Th1- and Th2-type Cytokines
Th2
Th1
Th1
Th2
BN
F344
SS?
FHH?
atopic
non-atopic
Th1-type IFN-g, IL-12 Th2-type IL-4, IL-5,
IL-13
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Are the Immune Responses of SS and FHH Rats
Th1-biased Like Those of F344 Rats?
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Screening Assay for Th1- and Th2-type Cytokine
Production by Spleen Cells
Con A
24 h
Measure Cytokine Levels in Supernatant Fluids
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IFN-g Production by Con A-stimulated Spleen Cells
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IL-4 Production by Con A-stimulated Spleen Cells
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IFN-g/IL-4 Ratio for Con A-stimulated Spleen Cells
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IL-13 Production by Con A-stimulated Spleen Cells
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IFN-g/IL-13 Ratio for Con A-stimulated Spleen
Cells
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Balance Between Th1- and Th2-type Cytokines
Th2
Th1
Th1
Th2
BN
F344
SS
FHH
atopic
non-atopic
Th1-type IFN-g, IL-12 Th2-type IL-4, IL-5,
IL-13
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Are SS Rats, Like F344 Rats, Resistant to the
Development of Post-bronchiolitis Airway
Dysfunction?
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Post-bronchiolitis Airway Dysfunction in BN, but
not SS, Rats
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Therefore, in vitro cytokine data and in vivo
physiology data suggest that the PhysGen consomic
rat strains will be useful tools for studying the
role of genetic factors in susceptibility/resistan
ce to the development of the post-bronchiolitis
asthma-like phenotype.
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Screening of Consomic Rat Strains

• SS.BN13
• SS.BN16
• SS.BN18
• SS.BN9
• SS.BN20

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Screening Assay for Th1- and Th2-type Cytokine
Production by Spleen Cells
Con A
24 h
Measure Cytokine Levels in Supernatant Fluids
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IFN-g Production by Con A-stimulated Spleen Cells
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Th1 and Th2 Cytokine Production

• No strain differences were observed among SS and
  these five SS.BN strains with regard to Con
  A-stimulated IFN-g production or IL-4 or IL-13
  production (not shown) .

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Chr. 20 Major Histocompatibility Complex

• SS.BN20
• Histocompatible with BN?
• Histoincompatible with SS?

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Two-way Mixed Lymphocyte Cultures
72 h
Strain A
Strain B
Measure IL-2 and IFN-g Levels in Supernatant
Fluids
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IL-2 Production in 2-way Mixed Lymphocyte
Cultures BN and SS.BN20 Splenocytes are
Histocompatible
BN BN
F344 F344
SS.BN20 SS.BN20
BN F344
F344 SS.BN20
BN SS.BN20
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IL-2 Production in 2-way Mixed Lymphocyte
Cultures SS and SS.BN20 Splenocytes are
Histoincompatible
BN BN
SS SS
SS.BN20 SS.BN20
BN SS
SS SS.BN20
BN SS.BN20
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IFN-g Production in 2-way Mixed Lymphocyte
Cultures SS and SS.BN20 Splenocytes are
Histoincompatible
BN BN
SS SS
SS.BN20 SS.BN20
BN SS
SS SS.BN20
BN SS.BN20
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Potential Uses of the Histocompatible SS.BN20
Strain for Studies in BN Rats

• in vitro
• cell mixing studies
• in vivo
• adoptive cell transfer studies
• organ transplant studies

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PhysGen Consomic Rat Development Timeline

• SS.BN12
• FHH.BN1 (IL-4Ra)
• SS.BN6 (Immunoglobulin)
• SS.BN7 (IFN-g)
• SS.BN8
• Fischer CDF(F-344)CrlBR
• BN/SsNHsd/Mcw

http//pga.mcw.edu
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Future Directions

• Continue screening spleens from adult consomic
  rats.
• PhysGen consomic rat strains to be distributed
• through Charles River Laboratories.
• Availability of weanling consomic rats will
  significantly increase options with regard to
  screening.
• Level of characterization of weanlings from each
  consomic strain? Resources that will inform
  these decisions include
• Rat Genome Database Rat Genome Sequencing
  Project
• Virtual Comparative Maps
• MCW-TIGR microarray expression profiling of rat
• consomic panels (lung)

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Funded by NIH/NIAID Asthma and Allergic Disease
Research Center Grant AI050500