| Full Name | CD19 molecule |
| Background | CD19 is a member of the immunoglobulin superfamily and has two Ig like domains. The CD19 molecule is expressed on 100% of the peripheral B cells as defined by expression of kappa or lamda light chains. It is expressed on approximately 10% of normal human peripheral blood cells and approximately 60% of splenic lymphocytes. It is not expressed on granulocytes, monocytes or T cells as defined by CD3 expression. CD19 defines a pan B antigen which is expressed from the earliest stages of B progenitor development, but is lost on terminal differentiation to plasma cells. It may also be present on some early myeloid progenitors, particularly those of the monoblastic type. The CD19 antigen is expressed on approximately 12% of peripheral blood lymphocytes. It appears to be expressed on myeloid leukemia cells, particularly those of monocytic lineage. Leukemia phenotype studies have demonstrated that the earliest and broadest B cell restricted antigen is the CD19 antigen. The receptor for CD19 is an important functional regulator of normal and malignant B cell proliferation. It is expressed in all B cell precursor leukemias. Recent cDNA cloning of CD19 has shown significant homology in the cytoplasmic domain of CD19 with the int1 oncogene. |
| Synonyms | B4, MGC12802, CD19, 107265, 930, P15391, CVID3 |
| Cellular Localization | Type I membrane protein. |
| Host | Mouse |
| Clonality | Monoclonal |
| Clone Name | LT19 |
| Isotype | IgG1 |
| Immunogen | Human B lymphoblast cell line Daudi. |
| Antigen Species | Human |
| Species Reactivity | Human |
| Conjugation | Phycoerythrin (PE) |