Related Experiment Videos
Production of human monoclonal antibodies to myeloperoxidase
M R Ehrenstein1, B Leaker, D Isenberg
1Department of Rheumatology Research, University College and Middlesex Hospital Medical School (UCMSM), London, U.K.
Abstract:
Two mouse-human heterohybridomas secreting human antibodies to myeloperoxidase (MPO) were derived from the peripheral blood of a patient who developed microscopic polyarteritis as the result of long-term treatment with hydralazine. Forty-five immunoglobulin-secreting lines were obtained from the fusion of patient lymphocytes with the CB-F7 heteromyeloma cell line. Of these, two antibodies, one IgG and one IgM, bound to myeloperoxidase in solid phase ELISA and gave a perinuclear staining pattern on ethanol-fixed human neutrophil cytospin preparations. The staining patterns were similar to those seen with serum from the patient. Antigen-inhibition studies revealed that the affinity of the IgG monoclonal antibody was 28 times higher (k = 1.4 x 10(-7)) than the IgM antibody (k = 5 x 10(-5)). Cross-inhibition studies further suggested that the two monoclonal antibodies recognized the same epitope on MPO. Of the other secreting cell lines, none produced antibody which reacted with the panel of autoantigens used for testing. Neither mononuclear antibody reacted with this panel indicating that they were not simply polyreactive natural autoantibodies. These are the first human monoclonal antibodies to native myeloperoxidase to be reported.
Insights
Researchers developed human monoclonal antibodies targeting myeloperoxidase (MPO) in a patient with hydralazine-induced polyarteritis. These antibodies are the first to recognize native MPO, offering potential for autoimmune disease research.
Area of Science:
- Immunology
- Autoimmunity
- Pharmacology
Background:
- Microscopic polyarteritis can develop from hydralazine treatment.
- Autoantibodies against myeloperoxidase (MPO) are implicated in autoimmune vasculitis.
- Generating human monoclonal antibodies is crucial for understanding autoimmune responses.
Purpose of the Study:
- To derive and characterize human monoclonal antibodies against myeloperoxidase (MPO).
- To investigate the binding affinity and epitope recognition of these novel antibodies.
- To explore their potential as tools in autoimmune disease research.
Main Methods:
- Fusion of patient lymphocytes with CB-F7 heteromyeloma cells to create heterohybridomas.
- Screening of immunoglobulin-secreting lines for MPO-specific antibodies using ELISA and immunofluorescence.
- Antigen-inhibition and cross-inhibition studies to determine antibody affinity and epitope specificity.
Main Results:
- Two human monoclonal antibodies (one IgG, one IgM) recognizing native MPO were successfully generated.
- Both antibodies exhibited perinuclear staining on neutrophils, consistent with patient serum patterns.
- The IgG antibody demonstrated a significantly higher affinity for MPO compared to the IgM antibody.
- Antibodies recognized the same MPO epitope and did not cross-react with other autoantigens.
Conclusions:
- The study reports the first human monoclonal antibodies against native myeloperoxidase (MPO).
- These antibodies provide valuable tools for studying MPO-directed autoimmunity, particularly in hydralazine-induced vasculitis.
- Further research may elucidate the role of MPO-specific antibodies in autoimmune pathogenesis.