|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1994 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1993 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Human multinucleated giant cells in normal and abnormal conditions were investigated using immunohistochemical methods. They were classified as type A and B.Type A includes osteoclasts, foreign body giant cells, Langerhans giant cell and others ; these are formed by cell fusion and are not able to divide anymore. Type B contains megakaryocytes, Reed-Sternberg (RS) cells, giant mesothelial cells and others. Their nuclei are connected by intercellular bridges and are able to proliferate. Thus, they are formed by endomitosis, i.e. nuclear division (mitosis) without cytokinesis.
Type A cells do not express PCNAs and receptors associated with cytoplasmic growth (CD25,71). Type B cells are typically observed as RS cells in Hodgkin's lymphoma, and their nuclei are strongly positive for various PCNAs in spite of rarity of apparent mitotic figures. Their cell membranes are positive for receptors for cytoplasmic growth (CD25,30,71) and differentiation antigens like CD75, HLA-DR and others. Thus, they are considered to have very long G1 stage during which the cell size are able to become abundant. Giant mesothelial cells are also found to be positive for CD30 and PCNAs. Non-dividing CMV-infected giant cells are interestingly found to have CD15 which is often expressed in RS cells.