Interaction of the lymphoid cell line BCL1 with lipopeptide analogues of bacterial lipoprotein: electron energy loss spectroscopy (EELS) as a novel method to detect the distribution of the activator within the cells.
The lipopeptide Pam3Cys-Ser, a synthetic analogue of the N-terminal part of bacterial lipoprotein, constitutes a potent activator for B lymphocytes, monocytes/macrophages and several lymphoid cell lines. We applied the novel method of electron energy loss spectroscopy (EELS) to determine, after stimulation, the distribution of the activator within the cell compartments of the lipopeptide sensitive cell line BCL1. Our results show that the lipopeptide, 20 min after the addition to the cell culture, was found at different locations within the cell: A major amount of the mitogen was found in the plasma membrane. Remarkably, considerable amounts of the activator were also found on the cytoplasm, the nuclear membrane, and the nucleus. After 24 h, a substantial amount of the lipopeptide was still present within the cells. These findings should help to elucidate the molecular mechanism of lymphocyte stimulation by lipopeptides. The novel method of EELS, which was demonstrated here using lipopeptides as examples, constitutes a valuable tool of localizing any given compounds such as growth factors or drugs within cells.
Wolf
B
B
Institut für Immunbiologie, Universitt Freiburg, Federal Republic of Germany.
Uhl
B
B
Hauschildt
S
S
Metzger
J
J
Jung
G
G
Bessler
W G
WG
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins; D002460:Cell Line; D004151:Dipeptides / Q000138:chemical synthesis / Q000378:metabolism*; D005615:Freezing; D008074:Lipoproteins / Q000138:chemical synthesis / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D013057:Spectrum Analysis / Q000379:methods; D013154:Spleen / Q000378:metabolism
D001426:Bacterial Proteins; D004151:Dipeptides; D008074:Lipoproteins; C047210:2,3-bis-(palmitoyloxy)-2-propyl-N-palmitoyl-cysteinylserine