Upload
cynthia-ryan
View
213
Download
0
Tags:
Embed Size (px)
Citation preview
Engineering Antibodies (2)Immunotherapeutic Examples
MSc Programme University of Nottingham
14th February 2005 by
Mike Clark, PhDDepartment of Pathology
Division of Immunology
Cambridge University
UK
www.path.cam.ac.uk/~mrc7/
University Research Programmes
• Immunosuppression
CD4, CD3, monovalent CD3, CD52 (Campath)
• Tumour Therapy
CD52 (Campath), bispecific CD3
• Organ Transplantation
CD52, CD3, CD4, synergistic CD45 pair
• Allo and auto-immunity
RhD, HPA-1a
• Chronic Inflammation
CD18, VAP-1
Declaration of interests (rights as an inventor)
• CD52 IlexOncology/Genzyme (Campath® humanisation)
• CD4 TolerRx/Genentech (for induction of tolerance)
• CD4 BTG (improved method of humanisation)
• CD3 BTG /TolerRx (immunosuppression and tolerance)
• CD18 Millennium Pharmaceuticals
• VAP-1 BioTie / University collaboration
• RhD NBS / University collaboration
• HPA-1a NBS / University collaboration
Fetomaternal alloimmune thrombocytopenia
• Maternal IgG raised against fetal platelet alloantigens can
cross the placenta and cause fetal platelet destruction
• If the fetal platelet count falls dangerously low, cerebral
hemorrage or death may result
• Current therapies are intrauterine platelet transfusion and
maternal therapy with high dose IVIG
Can a protective antibody be developed?
• 90% severe cases FMAIT are due to antibodies
against the alloantigen HPA-1a on GPIIIa
• Single B cell epitope (Leu-33) could be blocked
to prevent the binding of harmful antibodies
• Outcome depends on antibody titre
Williamson et al. Blood 1998; 92: 2280 Jaegtvik et al. Br J Obs Gynae 2000; 107: 691
Ideal properties of an antibody for FMAIT therapy
• HPA-1a specificity (B2 variable regions)
• able to cross the placenta
• inactive in FcR-mediated cell destruction
• unable to activate complement
Chemiluminescent response of human monocytes to sensitised RBC
-20
0
20
40
60
80
100
120
140
0 5000 10000 15000 20000 25000 30000
antibody molecules/cell
% c
hem
ilum
ines
cenc
e
G1
G1a
G1b
G1c
G1ab
G1ac
G2
G2a
G4
G4b
G4c
Fog-1 antibodies
Inhibition of chemiluminescent response due to 2 g/ml Fog-1 G1 by other Fog-1 antibodies
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100 1000
inhibitor concentration, g/ml
% c
hem
ilum
ines
cenc
e
G1 b
G1 c
G1ab
G1ac
G2
G2a
G4b
G4c
Inhibition by Fog-1 antibodies of ADCC due to clinically relevant polyclonal anti-RhD (at 3ng/ml)
0
20
40
60
80
100
120
0.1 1 10 100 1000 10000
inhibitor antibody concentration, ng/ml
% R
BC
lysi
s
G1 ab
G2
G2a
G4
G4 b
Selectins IgSF
4. Migration
Free flow
Infection
Chemokinesignal
Integrin
1. Captureand rolling
2. Activation 3. Stationaryadhesion
Endothelium
Multistep paradigm of neutrophil adhesion
Neutrophil adhesion assay
VAP-1
3. Ultra-rapid stationaryadhesion
2 IntegrinFc receptor
IgSF like motif
1. Capture and FcR ligation
2. Activation and integrin expression
Anti VAP-1 IgG
Microslide
Flow