FlowMAb APC anti-human CD19
Product Details
The 4G7 monoclonal antibody reacts with human CD19, a B cell-specific 95 kDa transmembrane glycoprotein of the immunoglobulin superfamily. CD19 contains two extracellular immunoglobulin-like domains and an extensive cytoplasmic tail. It functions as a positive regulator of B-cell receptor signaling in conjunction with CD21 and CD81. CD19 is highly expressed in most lymphomas and leukemias, including some early B-cell malignancies that do not express CD20. CD19 is emerging as an attractive alternative target for the immunotherapy of lymphoproliferative disorders. This allophycocyanin (APC)-conjugated version of the antibody is useful for flow cytometry and immunofluorescence applications.Specifications
| Isotype | Mouse IgG1 |
|---|---|
| Recommended Isotype Control(s) | FlowMAb APC mouse IgG1 isotype control, unknown specificity |
| Conjugation | APC |
| Excitation Source | Red 627-640 nm |
| Excitation Max | 651 nm |
| Emission Max | 660 nm |
| Immunogen | Human chronic lymphocytic leukemia (CLL) cells |
| Reported Applications |
Flow cytometry Immunofluorescence |
| Formulation |
PBS, pH 7.0 Contains 0.09% Sodium Azide |
| Production | Purified from cell culture supernatant in an animal-free facility |
| Purification | Protein G. Conjugated with allophycocyanin under optimal conditions. |
| Storage | The antibody solution should be stored at the stock concentration at 4°C and protected from prolonged exposure to light. Do not freeze. |
Additional Formats
Recommended Products
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Recommended Isotype Control(s)
FlowMAb APC mouse IgG1 isotype control, unknown specificity
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Recommended Dilution Buffer
InVivoPure pH 7.0 Dilution Buffer
Flow Cytometry
Miltiades, P., et al. (2015). "Three-fold higher frequency of circulating chronic lymphocytic leukemia-like B-cell clones in patients with Ph-Myeloproliferative neoplasms" Leuk Res . PubMed
Philadelphia chromosome-negative Myeloproliferative neoplasms (Ph-MPN) are accompanied by a markedly increased risk for development of chronic lymphocytic leukemia (CLL) compared to the general population. However, the pattern of onset and the biological characteristics of CLL in patients with coexistent Ph-MPN are highly heterogeneous rendering questionable if the above association reflects a causal relationship between the two disorders or merely represents a random event. By analyzing 82 patients with Ph-MPN and 100 age-matched healthy individuals we demonstrate that MPN patients have an almost threefold higher prevalence of, typically low-count, CLL-like monoclonal B lymphocytosis (MBL) compared to normal adults. The clone size remained unaltered during the disease course and unaffected by the administration of hydroxycarbamide, whereas no patient with Ph-MPN/MBL progressed to CLL during a median follow up of 4 years. Monoclonal B cells in Ph-MPN/MBL patients and normal individuals and in four more patients with coexistence of overt CLL and MPN displayed heterogeneous biological characteristics, while the JAK2V617F mutation was absent in isolated lymphocytes from Ph-MPN patients with coexistence of CLL. Despite its clinical and biological variability, the increased incidence of MBL in Ph-MPN patients along with the one reported for CLL further enforces the notion of a shared pathophysiology among the two malignancies via a common genetic link and/or microenviromental interactions.
Flow Cytometry
Smeltzer, J. P., et al. (2014). "Pattern of CD14+ follicular dendritic cells and PD1+ T cells independently predicts time to transformation in follicular lymphoma" Clin Cancer Res 20(11): 2862-2872. PubMed
PURPOSE: Transformation of follicular lymphoma is a critical event associated with a poor prognosis. The role of the tumor microenvironment in previous transformation studies has yielded conflicting results. EXPERIMENTAL DESIGN: To define cell subtypes associated with transformation, we examined tissue specimens at diagnosis from patients with follicular lymphoma that later transformed and, using immunohistochemistry (IHC), stained for CD68, CD11c, CD21, CXCL13, FOXP3, PD1, and CD14. Cell content and the pattern of expression were evaluated. Those identified as significantly associated with time to transformation (TTT) and overall survival (OS) were further characterized by flow cytometry and multicolor IHC. RESULTS: Of note, 58 patients were analyzed with median TTT of 4.7 years. The pattern of PD1(+) and CD14(+) cells rather than the quantity of cells was predictive of clinical outcomes. On multivariate analysis, including the follicular lymphoma international prognostic index score, CD14(+) cells localized in the follicle were associated with a shorter TTT (HR, 3.0; P = 0.004). PD1(+) cells with diffuse staining were associated with a shorter TTT (HR, 1.9; P = 0.045) and inferior OS (HR, 2.5; P = 0.012). Multicolor IHC and flow cytometry identified CD14(+) cells as follicular dendritic cells (FDC), whereas PD1(+) cells represented two separate populations, TFH and exhausted T cells. CONCLUSION: These results identify the presence of PD1(+) T cells and CD14(+) FDC as independent predictors of transformation in follicular lymphoma. Clin Cancer Res; 20(11); 2862-72. (c)2014 AACR.
Flow Cytometry
Rosa, D., et al. (2005). "Activation of naive B lymphocytes via CD81, a pathogenetic mechanism for hepatitis C virus-associated B lymphocyte disorders" Proc Natl Acad Sci U S A 102(51): 18544-18549. PubMed
Infection with hepatitis C virus (HCV), a leading cause of chronic liver diseases, can associate with B lymphocyte proliferative disorders, such as mixed cryoglobulinemia and non-Hodgkin lymphoma. The major envelope protein of HCV (HCV-E2) binds, with high affinity CD81, a tetraspanin expressed on several cell types. Here, we show that engagement of CD81 on human B cells by a combination of HCV-E2 and an anti-CD81 mAb triggers the JNK pathway and leads to the preferential proliferation of the naive (CD27-) B cell subset. In parallel, we have found that B lymphocytes from the great majority of chronic hepatitis C patients are activated and that naive cells display a higher level of activation markers than memory (CD27+) B lymphocytes. Moreover, eradication of HCV infection by IFN therapy is associated with normalization of the activation-markers expression. We propose that CD81-mediated activation of B cells in vitro recapitulates the effects of HCV binding to B cell CD81 in vivo and that polyclonal proliferation of naive B lymphocytes is a key initiating factor for the development of the HCV-associated B lymphocyte disorders.
Flow Cytometry, Immunofluorescence
Meeker, T. C., et al. (1984). "A unique human B lymphocyte antigen defined by a monoclonal antibody" Hybridoma 3(4): 305-320. PubMed
We produced a hybridoma designated 4G7 from a mouse immunized with chronic lymphocytic leukemia cells. The 4G7 hybridoma secretes an IgG1 antibody that is specific for normal and malignant B lymphocytes. Using dual color immunofluorescence staining, this antibody reacted with all immunoglobulin-positive cells but no T cells in normal peripheral blood. There was no detectable 4G7 antigen on monocytes, platelets, red cells, granulocytes, or phytohemagglutinin-activated T cells. When PBL were depleted of 4G7 positive cells and stimulated with pokeweed mitogen, secreted immunoglobulin levels fell to less than 10% of control values on Day 5 and less than 1% of control on Day 7. This antibody was reactive with 155 of 176 B lineage neoplasms on which it was screened. Thirty-five cases of myeloid or T-lymphoid malignancy were negative. Our studies show that the 4G7 antigen modulates in the presence of excess antibody. Free 4G7 antigen was not found circulating in human serum. The cell surface antigen identified by 4G7 was sensitive to pronase proteolysis but resistant to trypsin and chymotrypsin digestion. A comparison of 4G7 with other known B-cell antibodies indicates that the 4G7 antigen has not been previously identified. This antibody is of use for the identification of normal B lymphocytes, the study of B-cell differentiation, and the characterization of lymphoid malignancies.