Immunohistochemical evaluation of MRP-14 expression in epithelioid granuloma using monoclonal antibody 60B8.
Migration inhibitory factor-related protein (MRP) is expressed in myelomonocytic cells. However, extent of MRP-14 in expression in phagocytes, which are constituent cells of epithelioid granuloma, has been controversial: only weak signals or strong signals in a diffuse or irregular form were reported depending on the investigators. By immunohistochemical staining with a monoclonal antibody (MAb60B8) directed against MRP-14, we tried to correlate features of expression of MRP-14 protein in phagocytes with particular histopathologic stages of granuloma. We also examined expression of MRP-14 in the epithelioid cells and multinucleated giant cells induced in the human peripheral monocytes in vitro in the presence of 1,25-dihydroxyvitamin D3 (calcitriol). MRP-14 was positive in most of the phagocytes that were present in loose aggregates or irregular tubercles in the histopathologically early developmental stage of epithelioid granuloma. However, MRP-14 was positive for only few of the phagocytes present in distinct and discrete tubercles, i.e., in the definite epithelioid granuloma. In contrast to macrophages, most of the epithelioid cells and giant cells induced from cultured monocytes in vitro in the presence of calcitriol were negative for MRP-14. These results suggested that expression of MRP-14 in constituent cells may vary depending on the developmental stage of granuloma and supported that expression of this protein in phagocytes is restricted to the early stage of maturation differentiation of macrophages.
Arai
K
K
Department of Pathology, Shizuoka General Hospital, Japan.
Mizuno
K
K
Yamada
T
T
Nozawa
R
R
D000911:Antibodies, Monoclonal / Q000276:immunology; D000943:Antigens, Differentiation / Q000096:biosynthesis*; D040502:Calgranulin B; D002478:Cells, Cultured; D015622:Epithelioid Cells / Q000737:chemistry*; D006099:Granuloma / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D009000:Monocytes / Q000737:chemistry / Q000166:cytology; D009418:S100 Proteins / Q000096:biosynthesis*
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D040502:Calgranulin B; D009418:S100 Proteins