cDNA sequencing of mouse alpha 1-microglobulin/inter-alpha-trypsin inhibitor light chain and its expression in acute inflammation.

A cDNA encoding alpha 1-microglobulin (alpha 1mG)/inter-alpha-trypsin inhibitor light chain (ITI-LC) was cloned from mouse liver by reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends. Sequence analysis of the cDNA showed that the basic molecular structure of the proprotein was similar to that in other animals, so that two mature proteins, alpha 1mG and ITI-LC, could be produced from the proprotein translated from the mRNA. Since ITI-LC is known as a positive acute phase reactant and since ITI-LC is genetically identical with mast cell proteinase inhibitor, trypstatin, we examined the mRNA level in the liver of parasite-infected mice showing extensive mastocytosis. The mRNA level was, however, not significantly changed during inflammatory processes, except for a slight increase on day 8 post-infection.