Chemicals and Immunologic Lung Disease:Gene and Environment Meinir G Jones PhD ICSM London

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

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

Isocyanate asthma and HLA-DQB1 Bignon et al 1994

Balboni et al 1996

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

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

Chronic beryllium disease HLA-DPB1 Richeldi et al 1993

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

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

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

95% of CBD Glu % referents Glu69 ~10% develop CBD

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

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

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

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

Association of cobalt with HLA-DPB1Glu69 Potolcchio et al 1997

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

Panel of homozygous cell lines EBV-transformed B lymphoblastoid cell lines (Xth IHW)

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

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

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

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

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

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

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

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

Platinum study - subject characteristics

HLA-DR3 and Platinum sensitivity

HLA-DR6 and platinum sensitivity

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

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

Genetic susceptibility increased risk at high exposure of beryllium

Conclusions Identified genetic susceptibility Gene-environment interaction