title: Adsorptive or by pit formation endocytosis of immunoglobulins without loss of function as potential biotherapeutical application.
abstract: We here describe an alternative way to microinjection by which cellular transport of immunoglobulins through surface membranes can be achieved after binding to specific surface receptors either induced or constutively present, or via Fc receptors (Ig-mediated). In this report, the internalisation of two antibodies in two different cellular systems is analysed: the anti-p21ras monoclonal antibody (MoAb) after surface Ig binding on murine placental cells and anti-cdc2 MoAb that binds directly to its surface receptor expressed on the human promyelocytic leukemia cell line HL-60. In both cases, binding and internalisation is followed by Electron Microscopy (EM) and function is assessed by different assays. The first involves abrogation of class II antigen expression induced by Interferon-gamma (IFN-gamma) and 5-Azacytidine (5-AzaC) known to be mediated by activation of the ras pathway. The second involves growth cessation of HL-60 cells after antibody adsorption when a G1-S-specific culture supernatant containing anti-cdc2 activity is employed, whereas no growth hindrance is observed when a G2-M-specific anti-cdc2 MoAb is used. Thus, the antibodies do not follow the lysosyme pathway and do not lose their functional activity. This method may be applied in the future in order to achieve biological or clinical therapies.
authors.affiliation: University of Crete, Dpt. of Biology, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Vassiliadis
authors.forename: I
authors.initials: I
authors.lastname: Athanassakis
mesh_terms: D000327:Adsorption; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D001374:Azacitidine / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000276:immunology; D004705:Endocytosis; D005260:Female; D018922:HL-60 Cells; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008845:Microinjections; D016283:Proto-Oncogene Proteins p21(ras) / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II; D007371:Interferon-gamma; D016203:CDC2 Protein Kinase; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras); D001374:Azacitidine