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Experimental Animal Model s in Respiratory Diseases. Dr. Sibel Atış. Experimental Animal Model s in Respiratory Diseases. Why are men such rat?. Observation of functional and structural changes Ethiopathogenesis Defining of inflammatory processes - PowerPoint PPT Presentation
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Experimental Animal Models
in Respiratory Diseases
Dr. Sibel Atış
Why are men such rat?
Experimental Animal Models in Respiratory Diseases
• Observation of functional and structural changes
• Ethiopathogenesis
• Defining of inflammatory processes
• Observation of changes in airway behaviours
• Assessment of a new molecul effects
• Development of a treatment strategy
In Respiratory Diseases;
Animal model selection
Challenge system
• Animal Model - Selection Criteria– Species– Pathogenesis– Endpoints of study– Manipulations required– Cost
• Challenge System– Delivery of Agent– Challenge Dose– Strain or Form of Agent
Species
Pathogenesis
Endpoints of study
Manipulations required
Cost
Selection Criteria:
Selection of the Species
- Sensitivity to Agent
Pathogenesis
Endpoints of study
Manipulations required
Cost
Disease Animal species
Asthma mouse, murine, guinea pig, rat, dog, cat, monkey, pig
COPD Rodents, dog, monkey, pig
Lung Cancer mouse, murine, guinea pig
Tuberculosis mouse, murine, guinea pig, rat, primates (monkey)
Bacterial/viral Pneumoni Rodents, primates
Interstitial pnömonitis/fibrosis
Rodents, rat, dog, sheep, primates
Selection of the Species
Pathogenesis
- Similarity to Human Disease Process
Endpoints of study
Manipulations required
Cost
Asthma animal models:
Antigen induced asthma animal models;
- Bronchial hyperreactivity,
- Airway eosinophilic inflamation,
- mukus hipersecretion,
- high IgE levels
Asthma animal models:
- In mouse models: additionally, active Th2 cell or dendritic cell
infiltration
Asthma animal models:
Spontanous asthma animal models:
- “t bet” Knockout mice:
Allergic asthma protocols in C57BL/6 and BALB/c mice
Immünisation Aerosol allergen
OVA 25 μg/alum i.p., 0 & 5. day1% OVA, 60 min. 2 /daily, 12&13. day
OVA 10 μg in PBS i.p., 0 & 21. day1% OVA, 60 min. 2 /daily, 28&29. day
OVA presenting dendritic cell, i.p., 0. day
1% OVA, 60 min. 2 /daily7 & 8. day
Coagule egg white implant, s.c. , 0. day
1% OVA, min. 2 /daily10&11. day
Asthma animal models:
• Occupational asthma models:
– Toluene diisocyanate
– Trimellitic anhydride (TMA), respiratory sensitization,
– 1-chloro-2,4- dinitrobenzene (DNCB), dermal
sensitization,
(Vanoirbeek JAJ, et al, J Allergy Clin Immunol 2006)
COPD animal models:
Methods:
1) Elastase or exogenous agents (chemicals/particuls) induced
2) Cigarette smoke induced
3) Genetic intervention
COPD animal models :
1) Produced by elastase or exogenous agents:
• Porcine pancreatic elastase (PPE), papain and human neutrophil elastase:panasinary emphysema
- secretory cell metaplasi,
- pulmonary function impairment,
- hipoxemia,
- right ventricular hypertrophy
COPD animal models : Egzogen agents:
repeated endotoxin: neutrophil and active macrophage
Oxidants (Nitrogen dioxide): lung damage
Repeated nitrogen dioxide: focal emphysema
Osone: fibrosis Cadmium chloride:
emphysema with primary fibrosis Coul dust and silica:
focal emphysema
COPD animal models :
2) Cigarette smoke induced COPD
• Best COPD models in animals
• Emphysema, small airway lesions and secretory cell metaplasi like as in humans
• Similarities or differences between human and animals about cytokine profile, cell proliferation and apopitosis are little known.
COPD animal models :Important point in Cigarette smoke induced COPD models
a) need to time for emphysema lesions: It chages acording to;
• Animal to animals • Exposure dose • Exposure methods (nasal or whole body)
Min. 4 mounths (in some species 12 mounths )
b) Animal species• Dog: perfect emphysema• Guina pig: vasculary changes • Rat models: do not show this changes
COPD animal models :
3) Produced by Genetic intervention:
- Knockout mice
- Transgenic mice
Lung cancer models:
Best models in mouse:
1) spontouneus models
2) produced by full carcinogens
3) produced by Cigarette smoke
4) Transgenic and Knockout models
Lung cancer models :
Morphologic, histopatholojic and molecular characteristics like as human adenocancer.
Models of nonsmall cell CA shows not metastase.
Models of small cell CA shows a lot of characteristics of human cancer (including metastase)
Lung cancer models :
The important point for clinical applications of this models:
Need to be determine of their radiosensitivity and
chemosensitivity
Tuberculosis models: Robert Koch showed that M. tuberculosis inoculation induced
lesions like human disease.
Infection has been determined with M. tuberculosis cultures in a variety of animals.
Pathological reactions: Different pattern in different animals. – Rabbit / Pulmonary Tubercles– Mouse and Guinea Pig Usually Other Forms
Tuberculosis Pathogenesis in animals
Characteristics Mouse Guina pig Rabbit Monkey
Cellulary immunity
Good Poor Good Poorf
Caseous tissue
little much medium much
Disease characteristics
granuloma
Hematogendissemination Lung Destructionwith Caseous necrosis
Disease Healed witexcept ofcavity formation,
Hemathogen dissemination Lung destructionwith Caseous necrosis
Pneumonia models:
Bacterial pneumonia models:• S. pneumoniae, • K. pneumoniae, • P. Aeruginosa induced pneumonia
Bacterial pneumonia
1) Intratracheal
2) Directly nasal route (pulmonary infection rate ~ %100)
3) Whole body: aerosol exposure to bacteria
Pneumonia models:
Viral pneumonia models:
Any animal model shows not fully clinical disease spectrum of human viral pneumonia (e.g. RSV ).
Interstitial pneumonitis/fibrosis models:
Any animal model shows not fully clinical characteristics or histopathology of human disease
Models result in general fibrosis in lung paranchima
İnterstitial pneumonitis/fibrosis models:
Pulmonary fibrosis models can be produced by several exogenous agents in several animal species.
Pulmonary fibrosis models produced by
Bleomycine has been mostly used.
Pulmonay Fibrosis – Animal Models Egzogen agent Tissue damage mechanism Animal
BleomycineProinflamatory, fibrogenic
cytocines changes the transcription pathern
mouse, rat, hamster, rabbit, dog, primates
Inorganik particuls (silica, asbest)
Tip 4 hipersensitivity reactions (with or without granuloma formation
mouse, rat, hamster, rabbit, sheep
RadiationFree radical DNA damage mouse, rat, rabbit,
dog, primates, sheep
Gen transfer (TGF-, IL-1, GM-CSF)
Specific cytocine mouse, rat
Fluorescein isothiocyanat
Not fully understood mouse,
Vanadium pentoxideNot fully understood
mouse, rat,
Haptenic antigens( TBN sulfonic acidecompounds)
Remembered cellulary immunity mouse, hamster
Selection of the Species
Pathogenesis
Endpoints of study
Manipulations required
Cost
Endpoints of study:
Survival / mortality
Pathogenesis/pathology
Clininical Observation
- Pneumonia
- Respiratory and/or other symptoms (e.g. fever)
Clinical Biochemia (e.g. inflamation mediators)
Bacteriemia / Viremia
Functional / physiological assessment
Efficiency of a new molecul/ treatment agent
Vaccine efficiency
Selection of the Species
Pathogenesis
Endpoints of study
Manipulations required
Cost
Manipulations required:
– Radiography• Larger Animal Model
– Diagnostic procedures• Bronchoscopy, BAL,pulmonary catetherisation
– Physiological Monitoring • Pulmonary function, electrophysiology
– Exposure • Inhalation (Head-Only, Nose-Only, Whole-Body)• Others (Parenteral, Oral, intraperitoneal)
Selection of the Species
Pathogenesis
Endpoints of study
Manipulations required
Cost
• Animal cost:
– Rarely Unlimited Funds– Statistical Assessment Cannot Be Compromised– Cost Comparison
• Monkeys ~ $3,500-$5,000• Rabbits ~ $90-$100• Guinea Pigs ~ $45-$55• Rats ~ $25• Mice ~ $5• Genotypically Specialized Animals - Much More
Expensive
• Challenge system:
Challenge Dose
Delivery of Agent• IM, SQ, Oral, Nasal, Aerosol
Strain or Form of Agent• Different Infectivity characteristics and serotypes
Ajanın cinsi veya formu (Kullanılan ajanlar)
• Sensitize edici ajanlar (antijenler, allerjenler v.s)
• Gazlar; ozon, NO2, SO2 vb
• Partiküller; PM, çevresel partiküller, karbon, DEP,
nanopartiküller, asbest partikülleri vs
• Sigara dumanı, ürünleri
• Diğer toksik ajanlar
• Mikrobiyal ajanlar
• Lipopolisakkarit (selektif pulmoner nötrofiliye yolaçar)
• Çeşitli kanserojenler
Route of agent delivery
Animal Exposures Units
For several animalsFor one animal
CONCLUSIONS
Solunum sistemi hastalıklarında; etyopatogenez ve yeni bir tedavi ajanının etkileri başta olmak üzere daha birçok özellik hakkında detaylı bir değerlendirme imkanı verdiği için in vivo hayvan modellerine gereksinim vardır.
Solunum sistemi hastalığı ile ilgili deneysel bir hayvan modeli oluştururken, bu modelin insanlardaki kliniğe en iyi şekilde uyarlanabilmesi açısından hayvan modelinin seçimi ve model oluşturmada seçilecek ajan oldukça önemlidir.
CONCLUSIONS
Hayvan modellerinin bir takım kısıtlılıklarının da olduğu unutulmamalıdır. Spontan olarak solunumsal hastalık gelişen
model oldukça azdır. Hayvan modelleri ister istemez solunum sistemi
hastalığının tam fenotipik özelliklerini göstermez.
Her bir hayvan türünün kendine göre zayıf ve güçlü yanları olup, araştırıcı bunlar arasından test edeceği hipotez açısından en uygun modeli seçebilmelidir.
Thank you…Thank you…Doç.Dr. Sibel ATIŞDoç.Dr. Sibel ATIŞ
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