Morphological study of cytotoxicity produced by PSK-induced polymorphonuclear leukocytes (PMNs) and Nocardia rubra cell wall skeleton.
The morphologic changes in PMNs induced by an i.p. injection of PSK, a polysaccharide from the mycelia of Coriolus versicolor, and tumor cells undergoing cell death, were evaluated by immunohistochemical staining and electron microscopy. Male C3H/He mice, 8-10 -weeks old, received an i.p. injection of 125 mg/kg of PSK. Their PMNs were obtained 6 h after the PSK injection by peritoneal lavage. N-CWS (Nocardia rubra cell wall skeleton) was added at the start of the chromium release assay using the MM46 mammary carcinoma cell line, which is syngeneic to C3H/He mice, as target cells. During the cytotoxic assay, the cells were fixed at various time points. The MM46 cells expressed ICAM-1 while the PMNs expressed both ICAM-1 and LFA-1 as determined by immunohistochemical staining and immunoelectron microscopy using anti-ICAM-1 and anti-LFA-1 antibodies. PMNs with ruffle-like microvilli adhered to the MM46 tumor cells 30 min after the addition of N-CWS. Immunoelectron microscopic findings suggested that the adhesion molecules were LFA-1 on the PMNs and ICAM-1 on the MM46 tumor cells, but cell fusion between the PMNs and tumor cells was not observed. The MM46 tumor cells gradually lost their microvilli, which showed cell damage, and died 6-7 h after the addition of the N-CWS. This time course of tumor cell death is compatible with the results of the cytotoxic assay. Pretreatment of PMNs by anti-LFA-1 antibody suppressed 1% lysis of MM46 tumor cells from 90% to 10% (p < 0.01). These data suggest that adhesion molecule on the surface of PMNs such as LFA-1 might play an important role on signal transduction of these PMNs cytotoxic function in this experimental system.
Kata
H
H
First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.
Inoue
M
M
Mukai
S
S
Kawahito
Y
Y
Yoshida
T
T
Asai
K
K
Kimura
S
S
Hashiramoto
A
A
Yamamura
Y
Y
Sano
H
H
Sugino
S
S
Kondo
M
M
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D002448:Cell Adhesion; D017358:Cell Wall Skeleton / Q000494:pharmacology*; D003602:Cytotoxicity, Immunologic; D007150:Immunohistochemistry; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008854:Microscopy, Electron; D016253:Microscopy, Immunoelectron; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology / Q000648:ultrastructure; D009615:Nocardia / Q000648:ultrastructure; D011509:Proteoglycans / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D000276:Adjuvants, Immunologic; D017358:Cell Wall Skeleton; D016169:Lymphocyte Function-Associated Antigen-1; D011509:Proteoglycans; D018799:Intercellular Adhesion Molecule-1; C010770:polysaccharide-K