Engineering Antibodies (2) Immunotherapeutic Examples MSc Programme University of Nottingham 14 th...
-
Upload
cynthia-ryan -
Category
Documents
-
view
213 -
download
0
Transcript of Engineering Antibodies (2) Immunotherapeutic Examples MSc Programme University of Nottingham 14 th...
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