Demonstration of two distinct forms of released low-affinity type interleukin 2 receptors.
The release of interleukin 2 (IL2)-binding proteins, derived from the 55-kDa low-affinity IL2 receptor (IL2R; L chain), has been observed for virtually all L chain-bearing cells in either humans, the mouse or the rat. Based on the characterization of the released human L chain as a molecule 10 kDa smaller than the cell surface receptor, either proteolytic cleavage or differential splicing of the L chain-encoding mRNA have been suggested as mechanisms underlying the receptor release. Combining affinity labeling of the L chain with 125I-labeled IL2 and immunoprecipitation with L chain-specific monoclonal antibodies applied for the detection of soluble mouse IL2R revealed the existence of two classes of soluble receptors, one being of the same size as cell surface expressed L chain, the other of 45-kDa apparent molecular mass. These findings raise the possibility of mechanisms of receptor release other than those discussed for human L chain.
Josimovic-Alasevic
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O
Institut für Immunologie, Freie Universität Berlin, FRG.
Herrmann
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T
Diamantstein
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T
D000818:Animals; D000911:Antibodies, Monoclonal; D051379:Mice; D008970:Molecular Weight; D010449:Peptide Mapping; D011233:Precipitin Tests; D015375:Receptors, Interleukin-2 / Q000145:classification / Q000378:metabolism*; D012995:Solubility
D000911:Antibodies, Monoclonal; D015375:Receptors, Interleukin-2