Transfer of Torpedo acetylcholine receptors to mouse L-cell surface membranes by liposomes containing Sendai virus envelope proteins
Ho, S.C.; Huang, L.
European Journal of Cell Biology 27(2): 221-229
1982
ISSN/ISBN: 0171-9335 PMID: 6288378 Document Number: 189960
T. californica acetylcholine receptors (AchR) were reconstituted into liposomes in the presence or absence of Sendai virus envelope proteins (VEP). The 2 types of liposome were similar in size (60 nm diameter) and were mostly unilamellar. When liposomes were tested for immunoprecipitation, AchR in the AchR-VEP-liposomes, but not those in the AchR-liposomes, could be precipitated by anti-Sendai antibody, a result indicating that AchR and VEP were reconstituted into the same liposome populations. When the mouse L-929 cells were treated with AchR-liposomes, about 2.8 .times. 104 AchR molecules per cell became cell-associated. Immunofluorescence of the treated cells showed punctate fluorescent distribution of the AchR. Immunoferritin EM showed that most ferritin particles appeared on liposomes which had been adsorbed on the cell surfaces. Cells treated with AchR-VEP-liposomes showed about a 2-fold increase in the AchR molecules per cell. Immunofluorescence of the treated cells revealed ring fluorescent distributions of both AchR and VEP at the cell peripheries. Immunoferritin EM showed that most of the ferritin particles were directly on the cell surface and not associated with other membranous structures. Most of the AchR-liposomes adsorb on the cell surface without fusion with cells and AchR-VEP-liposomes fuse with cells resulting in transfer of AchR to the cell surface membranes. Cells treated with AchR-VEP-liposomes, but not with AchR-liposomes, showed specific antibody-dependent, complement-mediated cytotoxicity by anti-Sendai or anti-AchR antibody, a result confirming the above conclusions.