Researchers say they have generated a monoclonal antibody that could have diagnostic and therapeutic applications for multiple myeloma (MM) and other plasma cell disorders.
The team generated this antibody, VLRB MM3, from immunized lampreys, a type of jawless fish.
Experiments with VLRB MM3 showed that it can identify normal plasma cells in samples from healthy donors and malignant plasma cells in samples from patients with MM.
Götz Ehrhardt, PhD, of the University of Toronto in Ontario, Canada, and his colleagues described this work in JCI Insight.
The researchers noted that antibody-secreting plasma cells arise from B-cell precursors and are essential for adaptive immune responses against invading pathogens. Plasma cell dysfunction is associated with autoimmune and neoplastic disorders, including MM.
Surface markers that are specific to plasma cells have not been identified, and antibodies that only recognize these cells have been challenging to generate using conventional systems.
However, Dr Ehrhardt and his colleagues found they could generate a plasma-cell-specific antibody from immunized lampreys.
The researchers injected lamprey larvae with a bone marrow isolate from an MM patient and screened the resulting monoclonal antibodies for those that recognized both malignant and non-malignant plasma cells.
Further characterization of the antibody VLRB MM3 revealed that it is specific to plasma cells and does not recognize other B-cell populations or progenitors.
VLRB MM3 binding was shown to coincide with CD38 dimerization and correlate with and impede the NAD glycohydrolase activity of this glycoprotein.
Considering these findings together, the researchers concluded that VLRB MM3 represents a unique tool that might aid the treatment and diagnosis of plasma cell disorders.
