Human choriocarcinoma cell resistance to natural killer lysis due to defective triggering of natural killer cells.
The trophoblast, the outermost layer of the human placenta, lacks expression of the classical human leukocyte antigen (HLA) class I molecules. This prevents allorecognition by T cells but raises the question of what protects the trophoblast from natural killer (NK) cells. In a previous study, we have shown that choriocarcinoma cell (CC) resistance to NK lysis was mainly independent of HLA class I molecules. In the present study, we postulated that CC may prevent activation of NK cells by failing to stimulate their triggering receptors (TR). To test this hypothesis, we evaluated the lysis of JAR and JEG-3 CC after effective cross-linking and activation of NK cells by means of lectins or antibodies. Our results show that NK-resistant CC were sensitive to lysis by unstimulated peripheral blood lymphocytes in the presence of phytohemagglutin (PHA), to antibody-dependent cell cytotoxicity in presence of anti-Tja antibodies, and to monoclonal antibody redirected killing using anti-TR antibodies anti-CD16 and anti-CD244/2B4. Finally, CC fail to express CD48, the ligand for CD244/2B4. These results indicate that the resistance of CC to lysis results primarily from defective NK cell activation, at least partially due to the lack of expression of ligands, such as CD48, involved in the triggering of NK cells.
EA 3249 Cellules hématopoïétiques, hémostase et greffe, Faculté de Médecine, Tours, France.
Tony
T
Avril
Sophie
S
Iochmann
Denys
D
Brand
Pierre
P
Bardos
Hervé
H
Watier
Gilles
G
Thibault
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000920:Antibody-Dependent Cell Cytotoxicity / Q000502:physiology; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics; D018801:CD2 Antigens / Q000235:genetics; D000071178:CD48 Antigen; D045744:Cell Line, Tumor; D002822:Choriocarcinoma / Q000473:pathology*; D003602:Cytotoxicity, Immunologic; D018076:DNA, Complementary / Q000235:genetics; D005455:Fluorescent Antibody Technique; D006801:Humans; D007694:Killer Cells, Natural / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000235:genetics; D010835:Phytohemagglutinins / Q000494:pharmacology; D017452:Receptors, IgG / Q000235:genetics; D011971:Receptors, Immunologic / Q000235:genetics; D000071176:Signaling Lymphocytic Activation Molecule Family; D014162:Transfection
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018801:CD2 Antigens; C084093:CD244 protein, human; D000071178:CD48 Antigen; C000604065:CD48 protein, human; D018076:DNA, Complementary; C080568:Fc gamma receptor IIA; D008562:Membrane Glycoproteins; D010835:Phytohemagglutinins; D017452:Receptors, IgG; D011971:Receptors, Immunologic; D000071176:Signaling Lymphocytic Activation Molecule Family