scholarly journals Antigenic modulation of Friend virus erythroleukemic cells in vitro by serum from mice with dormant erythroleukemia.

1977 ◽  
Vol 146 (2) ◽  
pp. 520-534 ◽  
Author(s):  
E V Genovesi ◽  
P A Marx ◽  
E F Wheelock
Keyword(s):  
Cell Surface ◽  
Leukemia Virus ◽  
Surface Antigens ◽  
Immune Serum ◽  
Mouse Serum ◽  
Cell Surface Antigens ◽  
Antigenic Modulation ◽  
In Cells ◽  
Erythroleukemic Cells

Friend leukemia virus (FLV) erythroleukemic cells cultured in medium containing FLV-immune serum from dormant FLV-infected mice undergo modulation of FLV cell surface antigens. Modulation was determined by an increased resistance to FLV antibody-mediated complement-dependent lysis and was associated temporally with the capping of FLV-immune complexes at the cell surface. Modulated cells regained their susceptibility to FLV antibody-mediated complement-dependent lysis when transferred to medium containing normal mouse serum. After 48 h of culture in FLV-immune serum, 26% of the FLV erythroleukemic cells were devoid of FLV cell surface antigens as demonstrated by immunofluoresence. Antigenic modulation occurred to a greater extent in cells maintained in logarithmic growth than in cells in GO or resting phase. FLV-antigenic modulation is discussed as a possible mechanism by which antibody induces and maintains FLV-transformed cells in a dormant state.

Protective antigens of bloodstage Plasmodium knowlesi parasites

1984 ◽  
Vol 307 (1131) ◽  
pp. 159-169 ◽  
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Surface ◽  
Plasmodium Knowlesi ◽  
Surface Antigens ◽  
Red Cell ◽  
Cell Surface Antigens ◽  
Susceptible Host ◽  
Protective Antigens ◽  
Stage Of Development

The simian malaria Plasmodium knowlesi provides many favourable features as an experimental model; it can be grown in vivo or in vitro . Parasites of defined variant specificity and stage of development are readily obtained and both the natural host and a highly susceptible host are available for experimental infection and vaccination trials. Proteins synthesized by erythrocytic P. knowlesi parasites are characteristic of the developmental stage, as are the alterations that the parasite induces in the red cell surface. Erythrocytic merozoites are anatomically and biochemically complex, their surface alone is covered by at least eight distinct polypeptides. Immune serum from merozoite-immunized rhesus recognizes many parasite components, especially those synthesized by schizonts. All of the merozoite surface components and some of the schizont-infected red cell surface antigens are recognized by such immune sera. Rhesus monkeys rendered immune by repeated infection may by contrast recognize comparatively few antigens; a positive correlation was established for these ‘ naturally ’ immunized monkeys between protection and antibody directed against a 74000 molecular mass antigen. Im m unization with this purified antigen confers partial protection. O ther putative protective antigens have been identified by monoclonal antibodies that inhibit merozoite invasion of red cells in vitro . The antigens recognized by inhibitory monoclonal antibodies are synthesized exclusively by schizonts and are processed, at the time ofschizont rupture and merozoite release, to smaller molecules that are present on the merozoite surface. The multiplicity of protective antigens is clearly demonstrated by the fact that seven distinct merozoite surface antigens are recognized by three different inhibitory monoclonals. None of the protective antigens identified are variant or strain specific.

The Role of Cytokines in the Modulation of Cell Surface Antigens of Human Melanoma

1993 ◽  
Vol 8 (3) ◽  
pp. 151-154 ◽  
Author(s):  
A. Anichini ◽  
R. Mortarini ◽  
G. Parmiani
Keyword(s):  
Cell Surface ◽  
Surface Antigens ◽  
Surface Structures ◽  
Biological Behavior ◽  
Cell Surface Antigens ◽  
Membrane Expression ◽  
Neoplastic Cells ◽  
Antigenic Modulation ◽  
Human Malignant Melanoma ◽  
Cell Surface Structures

A number of different cytokines, including IL-1α. and ß, IL-2, IL-3, IL-4, IL-6, IL-7, IL-8, IFN-α, -ß and γ, TNF-α -ß, and TGF-ß1, can modulate the expression of distinct cell surface antigens of normal and neoplastic cells. Both induction/increase of expression and reduction of expression can be achieved depending on the antigen and on the cytokine. Antigens subjected to the modulating activity of cytokines include distinct families of cell surface structures such as the molecules coded by the major histocompatibility complex (MHC), the superfamily of adhesion receptors that regulate cell-cell and cell-matrix interaction, receptors for cytokines and growth factors and tumor-associated antigens. The modulating activity of cytokines is a consequence of their influence on gene expression, protein synthesis, membrane expression and shedding of antigens from the cell surface. The changes of phenotype due to the action of cytokines can influence the signalling pathways dependent on the expression and function of cell surf ace structures. Therefore, the antigen modulating activity of cytokines can thoroughly affect the biological behavior of normal and neoplastic cells. As described here, most of the modulating effects of cytokines on different cell surface structures and the functional consequences of antigenic modulation can be verified in human malignant melanoma cells.

Changes in cell surface antigens during in vitro lizard myogenesis

1983 ◽  
Vol 97 (2) ◽  
pp. 313-328 ◽  
Author(s):  
Michael F. Marusich ◽  
Sidney B. Simpson
Keyword(s):  
Cell Surface ◽  
Surface Antigens ◽  
Cell Surface Antigens

scholarly journals Cell surface antigens of chemically induced sarcomas of the mouse. I. Murine leukemia virus-related antigens and alloantigens on cultured fibroblasts and sarcoma cells: description of a unique antigen on BALB/c Meth A sarcoma.

1977 ◽  
Vol 146 (3) ◽  
pp. 720-734 ◽  
Author(s):  
A B DeLeo ◽  
H Shiku ◽  
T Takahashi ◽  
M John ◽  
L J Old
Keyword(s):  
Cell Surface ◽  
Cell Lines ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Surface Antigens ◽  
Cell Surface Antigens ◽  
Cultured Fibroblasts ◽  
Chemically Induced ◽  
Sarcoma Cells ◽  
Murine Leukemia

As background for a serological definition of the unique antigens of chemically induced sarcomas, we have typed a series of fibroblast and sarcoma cell lines of BALB/c and C57BL/6 origin by cytoxicity and absorption tests for murine leukemia virus (MuLV)-related cell surface antigens and known alloantigens. 7 of the 17 cultured lines expressed the range of cell surface antigens associated with MuLV (GIX, GCSA, gp70, p30), and this was invariably associated with MuLV production. In nonproducer lines of C57BL/6 (but not BALB/c) origin, a MuLV-gp70-like molecule was found on the surface of fibroblasts and sarcoma cells. The alloantigenic phenotype of these MuLV+ and MuLV- cell lines was H-2D+, H-2K+, Thy-1.2+ or -, PC.1+ or -, Lyt-1.2-, Lyt-2.2-, Ia.7-, and TL.2-. A unique antigen was defined on the BALB/c ascites sarcoma Meth A with antisera prepared in BALB/c or (BALB/c X C57BL/6)F1 mice. Tissue culture lines derived from this tumor were MuLV-, which facilitated serological study of the antigen. Absorption analysis indicated that the antigen was restricted to Meth A; it could not be detected in normal or fetal BALB/c tissue MuLV+ or MuLV- fibroblast lines, 12 syngeneic or allogeneic sarcomas, or normal lymphoid cells from 13 different inbred mouse strains.

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