Production of Free Light Chains of Immunoglobulin by a Hematopoietic Cell Line Derived from a Patient with Multiple Myeloma.

SummaryA cell line derived from a myeloma patient was found to produce only λ−type light chains of immunoglobulin which were secreted into the culture medium. There appears to be no formation of γ−, α−, or μ−heavy chains or of intact immunoglobulins. The light chains produced gave a reaction of identity with the Bence-Jones protein of the original patient's urine upon immunodiffusion and showed a similar molecular size upon gel filtration. The cells produced about 15 μg λ−chain per day per 106 cells (45 × 107 chain molecules per day per cell) under the culture conditions used.