Clinical Immunology Society
05 April 2008
Spontaneous Autoimmune Glomerulonephritis in HLA DQ2 Transgenic Mice
Shadi Rashtak MD.
Mayo Clinic Rochester
Requirements for the development of an autoimmune disease
Nature Immunology (9): 759-761 (2001)
MHC Class II Structure
Association of HLA DQ2/DR3 with multiple autoimmune diseases
Systemic Lupus Erythematosus Autoimmune hepatitis Celiac disease Grave’s Disease
HLA DQ2/DR3
Dermatitis herpetiformis Type 1 diabetes
Because of strong linkage disequilibrium between DQ2 and DR3 alleles it is difficult in human to address the exclusive role of HLA DQ2 in the pathogenesis of associated disorders
HLA DQ2 transgenic mice
• The HLA-DQ2 transgene is expressed HLAon a background that lacks endogenous MHC II (AEo).
Endogenous MHC class II is knocked out in AEo Mice
B6/j×129/j
Generation of DQ2 Transgenic Mice
• Dr. Mauro Rossi (Instituto di Scienze dell’Alimentazione, (Instituto dell’ Alimentazione,
Roma, Italy) provided the cDNA constructs for the α and β chains of DQ2. • These constructs were placed behind a mouse MHC II Eα Eα promoter.
HLA-DQ2 Transgenic Mice HLAProduction
(FVB) Embryos Pseudo-pregnant Mice
HLA-DQ2 cDNA construct
HLA-DQ2 (-)
HLA-DQ2 (+)
Insertion sites of the transgene in AEoDQ2 and AEoDQ6 mice AEoDQ2 AEoDQ6
A AEoDQ2
B
C AEoDQ6
D
AEo DQ2 (humanized) transgenic mice
DQ2 Expression
A skin disease spontaneously develops in AEoDQ2 mice
AEoDQ2 mice have IgA deposits at the dermal/epidermal junction
AEoDQ2 Mice
• Generally ill • Low activity levels • Low weight • involvement of other organs?
AEoDQ6 Mice
• Healthy • Normal activity levels • Normal weight • Good control for AEo DQ2 mice.
weight
N=6
60 50 weight (gr) 40 30 20 10 0 female male
N=16 N=5 P=0.003
AeoDQ2 AeoDQ6
N=7
N=6
N=16
P=0.018
Severe Proteinuria
Severe Proteinuria by Age and Genotype
100% 80% 60% 40% 20% AEoDQ2 0% AEoDQ6 0-6 months 6-12 months 12-18 months
Urine RBCs
Hematuria by Age and Genotype
100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 12-18 months 6-12 months 0-6 months
AEoDQ2 AEoDQ6
IgA deposition in the Kidney
AEoDQ2 AEoDQ6
C1q deposition in the Kidney
AEoDQ2 AEoDQ6
IgM deposition in the Kidney
AEoDQ2 AEoDQ6
IgG deposition in the Kidney
AEoDQ2 AEoDQ6
No C3a deposits were detected in the kidneys of
naive AeoDQ2 Mice
N=7
The intensity of glomerular deposition of complement protein C1q Increased by age in AEoDQ2 mice
2 months
A
3.5 months
B
5 months
C
8 months
D
Histopathology
AEoDQ2
AEoDQ6
Electron Micrographs
FPI
TRS
Anti-dsDNA Antibodies Anti3.5 3 A n ti- d s D N A Ig M ( O D ) 2.5 2 1.5 1 0.5 0
P<0.01
3.5 A n t i- d s D N A Ig G ( O D ) 3 2.5 2 1.5 1 0.5 0
P<0.01
A
0
AEºDQ2 0.5
1
AEºDQ6 1.5
2
B
0
0.5 AEºDQ2
1
1.5 AEºDQ6
2
Splenomegaly and lymphadenopathy
• 50% of the AEoDQ2 mice had
splenomegaly
• 60% of AEoDQ2 mice enlarged mesenteric
and/or cervical lymph nodes
Spleen Weight 0.25 M ean spleen weight (gr) 0.2 0.15 0.1 0.05 0 AEoDQ2
N=3
AEoDQ6
N=2
Summary Slide
• DQ2 dependent; AEo DQ2 transgenic mice
spontaneously develop autoimmune features, whereas AEoDQ6 mice do not. • Glomerulonephritis is one of these autoimmune features. • This nephropathy has lupus like features and appears to be mediated by immunoglobulin deposition.
Acknowledgment
• Dr. Eric V. Marietta • Dr. Joseph A. Murray • Dr. Chella S. David