Anti-CD33 [M195]

Absolute Antibody

Anti-CD33 [M195]

7

This antibody binds CD33, which is a 67 kD glycoprotein expressed on monocytes, hematopoetic progenitors, early myeloid progenitor cells and myeloid leukemias (acute and chronic) but not expressed on mature myeloid cells, normal stem cells, other hemtopoi

This antibody is recommended for myeloid differentiation studies, diagnosis of acute non-lymphoid leukemia cells and therapeutic treatment of myelois leukemia. Specificity of this antibody to CD33 was determined using RIA and immunoabsorption. Immunoflurorescence assay showed that the antigen is not expressed on adult human tissues (PMID: 2716349). Flow cytometric analysis was used to confirm reactivity of M195 with fresh hematopoietic neoplasms in the blood or bone marrow. In combination with MY9, this antibody is useful in diagnosis of acute myelogenous leukemia(AML) (PMID: 2725060). Murine antibody M195 was used in the phase I trial of AML (PMID: 1999719). Humanized IgG1 and IgG3 versions of this antibody has higher apparent binding affinity for CD33 antigen than the chimeric and parent murine version (PMID: 1737932, 1458463). The increase in binding affinity resulted from eliminating an N-linked glycosylation site at residue 73 in the heavy chain variable region in the course of humanization (PMID: 8232322). Preliminary trials to treat AML with humanized antibody showed specific bone marrow targeting without an immunogenic response (PMID: 8124221).

Flow Cytometry, ImmunoFluorescence, RadioImmunoAssay

RIA; IF; FC; Therapeutic

Research Use Only

Monoclonal

M195

CD33

CD33 molecule

CD33 antigen (gp67); CD33 molecule transcript; gp67; myeloid cell surface antigen CD33; p67; sialic acid-binding Ig-like lectin 3; SIGLEC3; SIGLEC-3

Human

IgG1

Myeloid cell surface antigen CD33

This chimeric human antibody was made using the variable domain sequences of the original Mouse IgG2a format, for improved compatibility with existing reagents, assays and techniques.

Human

Human

The original antibody was generated by immunizing mice with live leukemic myeloblasts.

-20°C,2°C to 8°C

12352203