Free immunoglobulin light chain synthesis by human foetal liver and cord blood lymphocytes.

Abstract

Immunoglobulin (Ig) synthesis by immature B lymphocytes from human foetal liver and cord blood has been investigated. Seven out of fifteen preparations of foetal liver cells and eight out of eleven cord bloods synthesized Ig detectable by biosynthetic labelling. All cultures of foetal lymphocytes with detectable Ig synthesis secreted free light chain. Two of these cases also synthesized free mu heavy chain. Cord blood lymphocyte synthesis patterns were variable ranging from free light chain as the only secreted Ig product to balanced synthesis of heavy and light chains. No cord blood cultures synthesized detectable free mu chains. Free Ig-light-chain synthesis appears to be associated with normal immature B lymphocytes and the results are discussed in relation to the B-cell differentiation pathway.