Transgenic mice with mu and kappa genes encoding antiphosphorylcholine antibodies.

Abstract

Transgenic mice were produced that carried in their germlines rearranged kappa and/or mu genes with V kappa and VH regions from the myeloma MOPC-167 kappa and H genes, which encode anti-PC antibody. The mu genes contain either a complete gene, including the membrane terminus (mu genes), or genes in which this terminus is deleted and only the secreted terminus remains (mu delta mem genes). The mu gene without membrane terminus is expressed at as high a level as the mu gene with the complete 3' end, suggesting that this terminus is not required for chromatin activation of the mu locus or for stability of the mRNA. The transgenes are expressed only in lymphoid organs. In contrast to our previous studies with MOPC-21 kappa transgenic mice, the mu transgene is transcribed in T lymphocytes as well as B lymphocytes. Thymocytes from mu and kappa mu transgenic mice display elevated levels of M-167 mu RNA and do not show elevated levels of kappa RNA, even though higher than normal levels of M-167 kappa RNA are detected in the spleen of these mice. Approximately 60% of thymocytes of mu transgenic mice produce cytoplasmic mu protein. However, despite a large amount of mu RNA of the membrane form, mu protein cannot be detected on the surface of T cells, perhaps because it cannot associate with T cell receptor alpha or beta chains. Mice with the complete mu transgene produce not only the mu transgenic mRNA but also considerably increased amounts of kappa RNA encoded by endogenous MOPC-167 like kappa genes. This suggests that B cells are selected by antigen (PC) if they coexpress the mu transgene and appropriate anti-PC endogenous kappa genes. Mice with the mu delta mem gene, however, do not express detectable levels of the endogenous MOPC-167 kappa mRNA. Like the complete mu transgene, the M-167 kappa transgene also causes amplification of endogenous MOPC-167 related immunoglobulins; mice with the kappa transgene have increased amounts of endogenous MOPC-167-like mu or alpha or gamma in the spleen, all of the secreted form. Implications for the regulation of immunoglobulin gene expression and B cell triggering are discussed.

Immunoglobulin gamma 2b transgenes inhibit heavy chain gene rearrangement, but cannot promote B cell development.

“…The transgene was isolated as an 11 .4-kb Sall to Pvul fragment by gel electrophoresis and elution from hydroxyapatite (10) . The 243-4 p transgenic line used as a control has been described (5,11). The A transgene encodes both the secreted and membrane forms of is and contains the VDJ region from myeloma MOPC 167 (11) .…”

“…The 243-4 p transgenic line used as a control has been described (5,11). The A transgene encodes both the secreted and membrane forms of is and contains the VDJ region from myeloma MOPC 167 (11) . The lidelS transgenic line contains a transgene that is a deletion derivative of the V 167A transgene used to generate the 243-4 ji line .…”

A VH12 Transgenic Mouse Exhibits Defects in Pre-B Cell Development and Is Unable to Make IgM+ B Cells

“…The 8/G0 Tg mice were bred with mice carrying the rearranged V1 gene of the S107 family (37). Providing a second H chain rearrangement bypasses the allelic exclusion barrier imposed by the 8/G0 transgene (see paragraph below), thereby allowing B cell development to be driven by a second H chain.…”

From gene amplification to V(D)J recombination and back: A personal account of my early years in B cell biology

“…While many options were considered at the time for how an isolated l H chain could provide its signal, he was convinced that it involved incorporation into the membrane and tried many experiments early on including tunicamycin treatment of A-MuLV-transformed cells to test the idea. Ultimately, transgenic models of others provided the first proof of the role of the membrane-bound form of the l H chain in signaling allelic exclusion, with the work of Nussenzweig and Leder being particularly definitive [41,42]. At the same time, Reth and I were also able to show the role of the membrane-bound form of the l protein in signaling developmental progression to the stage of IgL rearrangement via our studies of A-MuLV transformants [43].…”