Cell surface expression of the short immunoglobulin μ chain (Dμ protein) in murine pre‐B cells is differently regulated from that of the intact μ chain

Publisher Website
Google Scholar
Abstract
Pre‐B cells carrying DJH rearrangements in an appropriate reading frame produce a short μ protein consisting of a DJH and the Cü & sequence (ü protein). We analyzed a Dμ‐producing Abelson‐murine leukemia virus‐transformed murine pre‐B line, 300–19, and demonstrated that Dμ proteins are expressed on the cell surface in association with surrogate L chain proteins (Λ5 and VpreB). However, when we introduced an expression vector coding for the Dμ protein into the null pre‐B line P17–27, which produce Λ5 and VpreB but no Ig molecules, most of the cells did not express Dμ proteins on the cell surface although Dμ proteins were produced intracellularly. On the other hand, P17–27 brings intact μ chains on the cell surface, when a vector coding for the intact μ chain is introduced. Thus, cell surface expression of the Dμ protein has different requirements from that of the intact μ chain. A possible role of the VH protein encoded by germ‐line VH transcripts is discussed.