scholarly journals Diffusion rates of cell surface antigens of mouse-human heterokaryons. II. Effect of membrane potential on lateral diffusion.

1977 ◽  
Vol 75 (2) ◽  
pp. 483-489 ◽  
Author(s):  
M Edidin ◽  
T Y Wei

The rate of appearance, in a population of mouse-human heterokaryons, of cells with intermixed mouse and human surface antigens may be used to estimate the rate of lateral diffusion of the antigens in a single cell. Most heterokaryons appear to restrict diffusion of their surface antigens. These restrictions are altered by exposing either heterokaryons or their parent cells to conditions that change cell surface membrane potential. Media containing unphysiological concentrations of potassium ion, drugs, affecting the Na+,K+ ATPase, or a channel-forming antibiotic, gramicidin, all affect lateral mobility of cell surface antigens in a manner consistent with a common effect on membrane potential.

1982 ◽  
Vol 95 (2) ◽  
pp. 453-462 ◽  
Author(s):  
M Edidin ◽  
T Wei ◽  
L Gotlib

In mouse-human heterokaryons, the lateral diffusion of major histocompatibility (MHC) antigens in the plasma membrane is enhanced by treatment of parent cells with ouabain. Ouabain treatment is ineffective if the medium lacks calcium ion, or if Verapamil, a blocker of calcium channels, is present. The divalent ionophore A23187 also enhances lateral diffusion of MHC antigens, to the same extent as ouabain, A23187 is effective only if calcium is present in the medium. Thus it appears that increased levels of cell calcium release constraints to lateral diffusion of MHC antigens.


1974 ◽  
Vol 61 (3) ◽  
pp. 743-756 ◽  
Author(s):  
E. R. Phillips ◽  
J. F. Perdue

The distribution of neoantigens in the surface membrane of avian tumor virus-infected chicken embryo fibroblasts was examined on carbon replicas of cell cultures using hemocyanin-labeled antibody. New determinants appearing on the cell surface of virally infected but not transformed cells are thought to be common with components of the viral envelope. These antigens were found to exist in a diffuse, random array on the dorsal cell surface, with a denser accumulation along the cell processes. In living cells, surface antigens are capable of several types of redistribution when activated by reaction with antibody. Leukosis virus-infected (non-transformed) cells showed two apparently independent modes of redistribution: a relocation of some antibody-related sites to the cell margin; or an involvement of essentially all sites in randomly dispersed aggregates. Viral antigenic sites on sarcoma virus-infected (transformed) cells, reacted with antibody, were able to produce weak marginal relocation; but revealed a more striking tendency to migrate to some central location. The centripetal coalescence thus formed resembles the "cap" noted in other systems. Prior aggregation into "patches" may not be a prerequisite for such cap formation. Tumor-specific surface antigen detection and mapping was attempted by this technique, but results were equivocal. An antigen possibly characteristic of rapidly dividing cells occurred in a sparse, diffuse fashion over the surface of morphologically distinct "round" cells.


1977 ◽  
Vol 75 (2) ◽  
pp. 475-482 ◽  
Author(s):  
M Edidin ◽  
T Y Wei

The rate of appearance, in a newly formed heterokaryon population, of cells bearing completely intermixed mouse and human surface antigens may be used to estimate diffusion constants for antigens on individual cells. From this estimate, it appears that the surface antigens in most cells do not diffuse at the rate expected, but rather move more slowly, by a factor of ten or more, than expected from either measured or calculated diffusion constants for proteins freely mobile in the plane of a lipid membrane. Differences in diffusion rates between cells are not due to effects of Sendai virus, or of trypsin. Restrictions on diffusion are apparently not due to cytochalasin B- or Colcemid-sensitive elements.


Author(s):  
K. Chien ◽  
I.P. Shintaku ◽  
A.F. Sassoon ◽  
R.L. Van de Velde ◽  
R. Heusser

Identification of cellular phenotype by cell surface antigens in conjunction with ultrastructural analysis of cellular morphology can be a useful tool in the study of biologic processes as well as in diagnostic histopathology. In this abstract, we describe a simple pre-embedding, protein A-gold staining method which is designed for cell suspensions combining the handling convenience of slide-mounted cell monolayers and the ability to evaluate specimen staining specificity prior to EM embedding.


Author(s):  
Michael Edidin

Cell surface membranes are based on a fluid lipid bilayer and models of the membranes' organization have emphasised the possibilities for lateral motion of membrane lipids and proteins within the bilayer. Two recent trends in cell and membrane biology make us consider ways in which membrane organization works against its inherent fluidity, localizing both lipids and proteins into discrete domains. There is evidence for such domains, even in cells without obvious morphological polarity and organization [Table 1]. Cells that are morphologically polarised, for example epithelial cells, raise the issue of membrane domains in an accute form.The technique of fluorescence photobleaching and recovery, FPR, was developed to measure lateral diffusion of membrane components. It has also proven to be a powerful tool for the analysis of constraints to lateral mobility. FPR resolves several sorts of membrane domains, all on the micrometer scale, in several different cell types.


1993 ◽  
Vol 16 (10) ◽  
pp. 1054-1056
Author(s):  
Dai SASAKI ◽  
Satoshi KOSUNAGO ◽  
Takeshi MIKAMI ◽  
Tatsuji MATSUMOTO ◽  
Masuko SUZUKI

1971 ◽  
Vol 134 (4) ◽  
pp. 857-870 ◽  
Author(s):  
Darcy B. Wilson ◽  
Dianne H. Fox

The proliferative reactivity of lymphocytes from rat donors maintained under germfree or conventional conditions was examined in mixed lymphocyte cultures stimulated with allogeneic and xenogeneic cell surface antigens. The results show (a) that lymphocytes from conventionally maintained rats are less reactive to human, hamster, guinea pig, and mouse cell surface antigens than to the major H alloantigens, and (b) that lymphocytes from germfree rats display no demonstrable reactivity to xenogeneic cells, but are quantitatively normal in their response to allogenic cells. The conclusion drawn from these observations is that the circulating lymphocyte pool of an individual consists of a greater proportion of cells reactive to H alloantigens of other members of the same species than to the xenogeneic cellular antigens of members of other species and that this large number of cells is not generated by a mechanism involving immunization to cross-reactive environmental antigens.


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