Immunohistochemical demonstration of inter-alpha-trypsin inhibitor light chain (bikunin) in human mast cells.
We recently reported that the rat mast cell proteinase inhibitor trypstatin is genetically identical with the second half of inter-alpha-trypsin inhibitor light chain (ITI-LC), also known as bikunin or urinary trypsin inhibitor (UTI). In this study, therefore, immunoreactivities of mast cells of various human tissues were examined with three antibodies, anti-human ITI-LC, anti-ITI, which recognizes mainly heavy chains or the sugar moiety of ITI, and anti-alpha 1-microglobulin (alpha1mG). ITI-LC immunoreactivity was strongly found in mast cells in the connective tissues of various organs except for those of the propria mucosae of small intestine. Neither anti-ITI antibody nor anti-alpha1mG antibody reacted with mast cells in various tissues. By reverse transcription-polymerase chain reaction (RT-PCR) analysis, alpha1mG/ITI-LC mRNA was not detected in the skin and tongue, and only weakly in small intestine, although ITI-LC immunoreactivity was strongly detected in these tissues. Furthermore, the mRNA was not expressed in cultured human mast cells. These results suggest that ITI-LC protein is stored in the granules of human connective tissue mast cells, though is not produced by them.
Department of Parasitology, Miyazaki Medical College, Kiyotake, Miyazaki 889-1692, Japan.
H
H
Ide
H
H
Itoh
E
E
Yoshida
T
T
Kobayashi
M
M
Tomita
H
H
Maruyama
Y
Y
Osada
T
T
Nakahata
Y
Y
Nawa
D000510:Alpha-Globulins / Q000032:analysis / Q000235:genetics; D000818:Animals; D000918:Antibody Specificity; D002478:Cells, Cultured; D003239:Connective Tissue Cells / Q000166:cytology; D005786:Gene Expression Regulation; D006023:Glycoproteins / Q000032:analysis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000166:cytology; D007421:Intestine, Small / Q000166:cytology; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism; D008407:Mast Cells / Q000166:cytology* / Q000378:metabolism; D008562:Membrane Glycoproteins; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D014360:Trypsin Inhibitor, Kunitz Soybean
D000510:Alpha-Globulins; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; C109148:SPINT2 protein, human; C011877:inter-alpha-inhibitor; D014360:Trypsin Inhibitor, Kunitz Soybean