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Mott cells: a model to study immunoglobulin secretion
Author(s) -
Alanen Anna,
Pira Ulla,
Colman Alan,
Franklin Richard M.
Publication year - 1987
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/eji.1830171108
Subject(s) - biology , secretion , microbiology and biotechnology , antibody , immunoglobulin light chain , cell culture , clone (java method) , biochemistry , immunology , genetics , dna
Abstract Mott cells are plasma cells defective in immunoglobulin (Ig) secretion. They display this defect by accumulating Ig in the rough endoplasmic reticulum, detectable by Ig + intracellular inclusion. We have previously produced hybridoma cell lines (Alanen, A. et al., Eur. J. Immunol. 1985. 15: 235) in which this phenotype is preserved, and shown the inability of these cells to secrete the Ig. In order to study this defect further, we fused these hybridoma cells with a x‐secreting hybridoma cell line, Sp1, and, using double selection with hypoxanthine, aminopterin, thymidine and ouabain, obtained hybrid cell lines expressing various combinations of the three Ig chains involved (Mott γ1, Mott χ and Sp1 χ chains). We studied the presence of Ig + inclusions in these cells as well as Ig secretion by metabolic labeling and immunoprecipitation. All inclusion‐positive clones expressed both Mott heavy and Mott light chains with or without the Sp1 light chain, whereas none of the inclusion‐negative clones produced both Mott‐derived Ig chains. In all of the clones, even those with inclusions, the Ig secretion was at least partially rescued by the fusion. This occurred also in an inclusion‐positive clone which maintained the original Ig status of the Mott without Sp1 χ chain, indicating a complementation by the cell fusion of some cellular factor involved in Ig secretion. Furthermore, we injected Xenopus oocytes with mRNA isolated from three different original Mott cell hybridomas and could show secretion of the Ig, which is not secreted from the original Mott cells, from the oocytes.