CD20 expression in normal canine B cells and in canine non-Hodgkin lymphoma.
We examined the expression of CD20 in normal canine peripheral blood mononuclear cells, normal canine spleen, and canine non-Hodgkin lymphoma (NHL) to determine the feasibility of using this antigen as a diagnostic aid and as a possible target for therapy. An antibody generated against a C-terminal (intracytoplasmic) epitope of human CD20 recognized proteins of 32-36 kd in normal and malignant canine lymphocytes. This antibody showed restricted membrane binding in a subset of lymphocytes in peripheral blood, in the B-cell regions from a normal canine spleen and lymph node, and in malignant cells from 19 dogs with B-cell NHL, but not from 15 dogs with T-cell NHL. The patterns of CD20 reactivity in these samples overlapped those seen using an antibody that recognizes canine CD79a. This anti-CD20 antibody is therefore suitable as an aid to phenotype canine NHL. In contrast, normal canine B cells were not recognized by any of 28 antibodies directed against the extracellular domains of human CD20 (including the chimeric mouse-human antibody Rituximab) or by any of 12 antibodies directed against the extracellular domains of mouse CD20. Thus, the use of CD20 as a therapeutic target will require the generation of specific antibodies against the extracellular domains of canine CD20.
Jubala
C M
CM
Integrated Department of Immunology, AMC Cancer Center, University of Colorado Health Sciences Center, 1600 Pierce Street, 2-Diamond Research Building, Denver, CO 80214, USA.
Wojcieszyn
J W
JW
Valli
V E O
VE
Getzy
D M
DM
Fosmire
S P
SP
Coffey
D
D
Bellgrau
D
D
Modiano
J F
JF
D000818:Animals; D000906:Antibodies / Q000378:metabolism; D018951:Antigens, CD20 / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism*; D004283:Dog Diseases / Q000276:immunology / Q000378:metabolism*; D004285:Dogs; D005434:Flow Cytometry / Q000662:veterinary; D015972:Gene Expression Regulation, Neoplastic; D015151:Immunoblotting / Q000662:veterinary; D016130:Immunophenotyping / Q000662:veterinary; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology / Q000378:metabolism / Q000662:veterinary*; D010784:Photomicrography / Q000662:veterinary
D000906:Antibodies; D018951:Antigens, CD20