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Updated: Aug 8, 2026
Generation of Human CD40-activated B cells
Published on: October 17, 2009
Characterization of an immunosuppressive anti-CD40 ligand monoclonal antibody
1Laboratory of Immunology, College of Pharmacy, Seoul National University, Korea.
Insights
Researchers developed a novel monoclonal antibody, 2B2, targeting human CD40 ligand (CD40L). This antibody effectively suppresses B-cell immune responses in vivo, showing potential for treating autoimmune diseases.
Area of Science:
- Immunology
- Molecular Biology
- Autoimmune Diseases
Background:
- CD40 ligand (CD40L) interaction with CD40 is crucial for immune responses.
- Unresolved questions remain regarding CD40L function in human in vivo systems.
- Need for immunosuppressive agents targeting CD40L.
Purpose of the Study:
- To clarify the function of CD40L in vivo.
- To develop an immunosuppressive agent targeting CD40L.
- To characterize a novel anti-CD40L monoclonal antibody (MAb 2B2).
Main Methods:
- Generation and characterization of MAb 2B2 specific for human CD40L.
- Enzyme-linked immunosorbent assay (ELISA) and flow cytometry for specificity verification.
- Immunoprecipitation of CD40L from human peripheral blood lymphocytes (PBLs).
- In vivo studies using severe combined immunodeficiency (SCID) mice reconstituted with human PBLs.
- Polymerase chain reaction (PCR) for cloning and sequencing of MAb 2B2 variable region genes.
Main Results:
- MAb 2B2 demonstrated specificity for human CD40L.
- MAb 2B2 immunoprecipitated proteins of 35 and 28 kD from stimulated human PBLs.
- MAb 2B2 significantly suppressed human IgG production in human B cells transplanted into SCID mice.
- Sequencing revealed MAb 2B2 heavy and light chain variable regions belong to specific subgroups.
Conclusions:
- MAb 2B2 effectively suppresses human B-cell immune responses in vivo.
- MAb 2B2 holds potential for regulating immune responses in autoimmune diseases.
- The characterized MAb 2B2 provides a basis for developing immunosuppressive chimeric or humanized anti-CD40L antibodies.
Abstract:
The interaction between CD40 ligand (CD40L) and its counter-receptor CD40 is critically important in T- and B-cell costimulation and generation of the humoral immune response. But several questions still remain unsolved, particularly in the human in vivo system. To clarify the precise function of CD40L and develop an immunosuppressive agent, we have generated a murine monoclonal antibody (MAb), 2B2 specific for human CD40L. The specificity of this MAb for human CD40L was verified by enzyme-linked immunoadsorbent assay (ELISA) and flow cytometry. MAb 2B2 immunoprecipitated proteins of molecular weight 35 and 28 kD on human peripheral blood lymphocytes (PBLs) stimulated with phorbol 12-myristate-13-acetate (PMA) plus ionomycin. Then we have studied the biological effect of MAb 2B2 in severe combined immunodeficiency (SCID) mice reconstituted with human PBLs. The data showed that this MAb strongly suppressed human IgG production of human B cells transplanted in SCID mice, indicating that this MAb 2B2 could be used to regulate unwanted immune responses associated with autoimmune disease. Then we analyzed the sequence of MAb 2B2. The 2B2 heavy chain variable region (VH) and light chain variable region (VL) genes were cloned using PCR. The cloned VH gene coded for 123 amino acid residues and belonged to the subgroup III(D). The VL gene coded for 126 amino acid and belonged to the subgroup V. Collectively, these results will be used to develop an immunosuppressive chimeric or humanized anti-CD40L antibody.
