Immunophenotypical changes of neoplastic cells and tumor-associated macrophages in a rat dendritic cell sarcoma-derived transplantable tumor line (KB-D8).
Basically, dendritic cell-derived sarcomas are characterized by expression of major histocompatibility complex class-II molecules, but the biological properties of the tumor cells remain to be elucidated. Recently, we established a novel transplantable cell line (KB-D8) from a dendritic cell sarcoma found in an F344 rat. In the present study, we investigated immunophenotypical changes of KB-D8 tumor cells and tumor-associated macrophages (TAMs) appearing in relation to tumor development in syngeneic F344 rats. A number of neoplastic cells in 0.5-cm-diameter KB-D8 tumors showed immunoreactions to OX6 (specific for rat antigen-presenting cells), ED1 (for rat exudate macrophages), and ED2 (for rat resident macrophages), and 72% and 11% of the OX6+ cells were double-immunostained with ED1 and ED2, respectively. Interestingly, the immunoreactions to these antibodies were gradually reduced with increasing size of KB-D8 tumors of 1-, 2-, and 3-cm diameter. These findings indicated that immunophenotypes of dendritic cell-derived sarcomas may be changeable depending on microenvironmental conditions in vivo. Many TAMs seen outside KB-D8 tumors reacted to OX6, ED1, and ED2; the numbers of TAMs immunopositive for these antibodies also decreased as the tumor grew. Similarly, the earlier temporary increase and subsequent gradual decrease in ED2+ and OX6+ cell numbers were observed in the spleen and liver of KB-D8-bearing rats. The reverse-transcription polymerase chain reaction showed mRNA expressions of granulocyte/macrophage-colony stimulating factor, monocyte-chemoattractant protein-1, and osteopontin in KB-D8 tumor tissues. Although the functional roles (biphasic roles: suppressing or promoting) of these factors should be investigated further in relation to tumor development, the factors might be partially responsible for the TAM reactions. KB-D8 would be a useful experimental model to investigate the biological characteristics of dendritic cell sarcomas and tumor immunology in the host.
Kawashima
Maki
M
Laboratory of Veterinary Pathology, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Gakuencho 1-1, Sakai, Osaka 599-8531, Japan.
Ide
Mika
M
Nakanishi
Masako
M
Kuwamura
Mitsuru
M
Kumagai
Daijiro
D
Yamate
Jyoji
J
D000818:Animals; D000911:Antibodies, Monoclonal; D002452:Cell Count; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D003713:Dendritic Cells / Q000276:immunology* / Q000473:pathology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping / Q000379:methods; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008297:Male; D053495:Osteopontin; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012513:Sarcoma, Experimental / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D012795:Sialoglycoproteins / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D018932:Chemokine CCL2; D017931:DNA Primers; D000949:Histocompatibility Antigens Class II; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor