FRL2 Antibody

Introduction to FRL2 Antibody (MAB2048)

The FRL2 antibody, designated as MAB2048, is a mouse monoclonal antibody targeting FCRL2/FcRH2 (Fc receptor-like 2) and FCRL5/FcRH5 (Fc receptor-like 5). These proteins belong to the immunoglobulin superfamily and are expressed on B cells, with roles in immune regulation and malignancy. Below is a detailed analysis of its characteristics, applications, and research findings.

Target Specificity and Cross-reactivity

MAB2048 exhibits specificity for FCRL2/FcRH2 and FCRL5/FcRH5 but demonstrates partial cross-reactivity with other FCRL family members:

Key Observations:

• High specificity: The antibody reliably detects FCRL2/FcRH2 in human peripheral blood mononuclear cells (PBMCs) when paired with CD19 (a B cell marker) in flow cytometry .

• Format limitations: Cross-reactivity with FCRL1, FCRL3, and FCRL4 is restricted to Western blotting and not observed in flow cytometry .

Research Applications and Experimental Data

A. Flow Cytometry:
MAB2048 is validated for detecting FCRL2/FcRH2 in PBMCs. A representative gating strategy includes:

1. Primary staining: MAB2048 followed by APC-conjugated anti-mouse IgG F(ab’)₂ secondary antibody.

2. Control antibody: MAB002 (isotype-matched negative control).

3. B cell identification: CD19 PE-conjugated antibody for gating B cell populations .

B. Western Blotting:

• Detects FCRL2/FcRH2 and FCRL5/FcRH5 in lysates from B cell malignancies (e.g., B-cell chronic lymphocytic leukemia, B-CLL).

• Cross-reactivity with FCRL1, FCRL3, and FCRL4 occurs at ~25% efficiency, necessitating careful validation in lysates .

Clinical and Biological Relevance of FCRL2

A. Expression Patterns:

B. Functional Insights:

• B cell malignancy: FCRL2 is upregulated in B-CLL and associated with less aggressive disease phenotypes .

• Genomic location: The FCRL2 gene maps to 1q21-23, a region prone to translocations in B cell cancers .