Chemicals and Immunologic Lung Disease:Gene and Environment

1. Chemicals and Immunologic Lung Disease:Gene and Environment Meinir G Jones PhD NHLI @ ICSM London

2. Only a minority of subjects exposed develop disease • Cases tend to develop within the first two years of exposure • Exposure response - disease develops at low exposures • Suggestive of immune response gene effects

3. Sensitisation to acid anhydrides and association with HLA-DR3 Young et al 1995

4. Isocyanate asthma and HLA-DQB1 Bignon et al 1994

5. Balboni et al 1996

6. DQB1*0503 and *0501 differ by one amino acid at position 57 • DQB1*0503 has aspartic acid at position 57 • DQB1*0501 has valine at position 57

7. Possible role for Aspartic acid at position 57 - HLA-DQB1 Balboni et al 1996

8. Chronic beryllium diseaseHLA-DPB1 Richeldi et al 1993

9. HLA-DPB1*0201 and *0401 differ at three positions • position 36 • position 55 and 56 - aspartic acid, glutamic acid /alanine, alanine • position 69 - glutamic acid /valine

10. HLA-DPB1 Glutamate 69 • DPB1*0201 - glutamate at position 69 • DPB1*0401 - valine at position 69 • Glu69 variant - 97% CBD cases 27% referents Richeldi et al 1993

11. Position 57 DQB1 associated with insulin dependent diabetes mellitus and isocyanate induced asthma • Position 71 DRB1 associated with rheumatoid arthritis • The side chains of DP Glu69 and Asp55 are projected towards the peptide binding cleft

13. 95% of CBD Glu69 • 30-45% referents Glu69 • ~10% develop CBD

14. HLA-DPB1 Glu69 • Glu69/Glu69 - 6/20 (30%) CBD -1/75 (1%) control Wang et al 1999

15. Phenotypic frequency of Glu69 carriers in CBD and referents Wang et al 1999

16. CBD carried predominantly non-*0201 allele (84%) • Controls carried predominantly *0201 allele (68%)

17. Specific Glu69 alleles and copy numbers may confer greatest susceptibility on CBD

18. Association of cobalt withHLA-DPB1Glu69 Potolcchio et al 1997

19. T cell responses to beryllium • 25 T cell clones raised from 3 CBD patients • All proliferated to Be, but not Co or Ni Lombardi et al 2001

20. Panel of homozygous cell lines • EBV-transformed B lymphoblastoid cell lines (Xth IHW) • 02012 • 0402 • 1001

21. All were restricted by HLA-DP alleles with Glu69 • T cell response to Be completely inhibited by anti-DP mAb

22. Is Glu69 critically important in T cell recognition of Be? • Murine DAP.3-DP2 transfectants • only 3/12 T cell clones able to respond to DAP.3DP2 transfectants • DPB1*0201 recognised, but not *0402

23. T cell response to beryllium • T cell lines raised from lungs of CBD patients • T cell response inhibited by anti-DP • DP alleles which presented beryllium matched those implicated in disease association studies Fontenot et al 2000

24. Beryllium binding to HLA-DP • Soluble HLA-DP2 molecule • Glu69 variant • mutated lysine at position 69 Amicosante et al 2001

25. Beryllium could compete out from DP Glu69 molecule the biotinylated-CLIP at low concentration • Be bound at pH 5 and 7.5 - suggesting Be bound in absence of antigen processing • Be altered the binding of a mAb, thought to recognise epitopes within the binding groove

26. Cobalt binding to DP • HLA-DP but not -DR bound cobalt • DP*0201 bound cobalt at least three times more efficiently than *0401 (Asp55/Glu69) • DP*0201 binds more cobalt than *0402 (Glu69) • DP*0402 binds more cobalt than *0401 (Asp55) Potolicchio et al 1999

27. Strong evidence from disease association and binding studies of genetic susceptibility • Is there a gene environment interaction?

28. Association of HLA-DR3 with exposure to anhydrides in the development of specific IgE

29. Platinum study - subject characteristics

30. HLA-DR3 and Platinum sensitivity

31. HLA-DR6 and platinum sensitivity

32. Strength of HLA-DR3 and DR6 association with sensitisation to platinum varies with intensity of exposure

33. CBD, HLA-DPB1 Glu69 and Be exposure Richeldi et al 1997

34. Genetic susceptibility increased risk at high exposure of beryllium

35. Conclusions • Identified genetic susceptibility • Gene-environment interaction