The role of algal antigenic determinants in the recognition of potential algal symbionts by cells of Chlorohydra

1979 ◽  
Vol 35 (1) ◽  
pp. 367-379
Author(s):  
R.R. Pool
Keyword(s):  
Cell Surface ◽  
Algal Cell ◽  
Antigenic Determinants ◽  
Digestive Cells ◽  
Green Hydra ◽  
Algal Symbionts ◽  
Two Systems

Algal cells grown in the green hydra Chlorohydra viridissima were shown to possess characteristic antigenic determinants not found in algae cultured in vitro. These antigenic determinants, including those localized on the algal cell surface, were shown to be responsible for the phagocytic recognition of potential algal symbionts by digestive cells of Chlorohydra. The results of this study indicate the existence of two systems governing phagocytosis in Chlorohydra, one specific for algal cells grown in hydra, another governing the uptake of other particles by the hydra digestive cells.

scholarly journals Role of a nonimmunoglobulin cell surface determinant in the activation of B lymphocytes by thymus-independent antigens.

1979 ◽  
Vol 149 (2) ◽  
pp. 495-506 ◽  
Author(s):  
B Subbarao ◽  
D E Mosier ◽  
A Ahmed ◽  
J J Mond ◽  
I Scher ◽  
...  
Keyword(s):  
Cell Surface ◽  
B Cell ◽  
B Lymphocytes ◽  
Selective Inhibition ◽  
Antibody Responses ◽  
Antigenic Determinants ◽  
Functional Assay ◽  
Induce Antibody

Lyb 5 is a B-cell alloantigen which is expressed on 50-60% of B cells. It was defined originally on the basis of cytotoxicity. We have described a new reactivity within the anti-Lyb 5 serum on the basis of selective inhibition of antibody responses in vitro by this antiserum in the absence of complement. This inhibitory activity of anti-Lyb 5.1 serum appears to be due to recognition of antigenic determinants different from the prototype antigens detected in the cytotoxicity assay. Anti-Lyb 5 serum incorporated into spleen cell cultures selectively inhibits antibody responses to a class of thymus-independent antigens (TI-2) previously characterized by their failure to elicit antibody formation in immature mice or in the defective CBA/N strain. Responses to optimal concentrations of TI-1 antigens, which can induce antibody synthesis in these mice, are unaffected by the addition of anti-Lyb 5.1 serum. The B-cell alloantigen defined by this functional assay is designated tentatively Lyb 7 and it is shown to be distinct from cell surface immunoglobulins. Lyb 7 appears to have a role in the activation of B lymphocytes by the TI-2 class of thymus-independent antigens.

Neural induction and the structure of the target cell surface

Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 171-187
Author(s):  
A. M. Duprat ◽  
L. Gualandris ◽  
P. Rouge
Keyword(s):  
Cell Surface ◽  
Structural Integrity ◽  
Neural Induction ◽  
Active Role ◽  
Target Cells ◽  
Similar Treatment ◽  
Structural Modifications ◽  
Pleurodeles Waltl

Lectins (SBA and PSA) were used to provoke crowding and structural modifications of the presumptive ectoderm cell surface in order to investigate the role of the membrane organization of the competent target cells in neural induction. Are specific characteristics of the cell surface essential for this phenomenon to occur? From amphibian gastrulae, it is possible to obtain neural induction in vitro by association of presumptive ectoderm (target cells) with chordamesoderm (inductor tissue): 4 h of contact is sufficient in Pleurodeles waltl for transmission of the inductive signal. Very quickly, the treatment of the normal ectoderm by lectins (SBA-FITC or PSA-FITC) provoked surface modifications. Lectin-treatment (50 µg ml1−, 30 min) of presumptive ectoderm did not result in any neural induction. Lectin-treatment (50 µg ml1−, 30 min) of presumptive ectoderm previous to its association with the natural inductor for 4 h, disturbed the phenomenon: no induction. Similar treatment followed by association with the inductor for 24 h: induction. Treatment of SBA or PSA with their respective hapten inhibitors prior to addition to ectodermal cells completely blocked the suppressive effects on induction. The structural integrity of the membrane of competent target cells is necessary for neural induction to occur. The cell membrane could thus play, directly or indirectly, an active role in the specificity of this process

scholarly journals MiR-26a-5p inhibits GSK3β expression and promotes cardiac hypertrophy in vitro

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10371
Author(s):  
Liqun Tang ◽  
Jianhong Xie ◽  
Xiaoqin Yu ◽  
Yangyang Zheng
Keyword(s):  
Cell Surface ◽  
Cardiac Hypertrophy ◽  
Surface Area ◽  
Myocardial Cell ◽  
Immunofluorescence Staining ◽  
Cell Surface Area ◽  
Direct Target

Background The role of miR-26a-5p expression in cardiac hypertrophy remains unclear. Herein, the effect of miR-26a-5p on cardiac hypertrophy was investigated using phenylephrine (PE)-induced cardiac hypertrophy in vitro and in a rat model of hypertension-induced hypertrophy in vivo. Methods The PE-induced cardiac hypertrophy models in vitro and vivo were established. To investigate the effect of miR-26a-5p activation on autophagy, the protein expression of autophagosome marker (LC3) and p62 was detected by western blot analysis. To explore the effect of miR-26a-5p activation on cardiac hypertrophy, the relative mRNA expression of cardiac hypertrophy related mark GSK3β was detected by qRT-PCR in vitro and vivo. In addition, immunofluorescence staining was used to detect cardiac hypertrophy related mark α-actinin. The cell surface area was measured by immunofluorescence staining. The direct target relationship between miR-26a-5p and GSK3β was confirmed by dual luciferase report. Results MiR-26a-5p was highly expressed in PE-induced cardiac hypertrophy. MiR-26a-5p promoted LC3II and decreased p62 expression in PE-induced cardiac hypertrophy in the presence or absence of lysosomal inhibitor. Furthermore, miR-26a-5p significantly inhibited GSK3β expression in vitro and in vivo. Dual luciferase report results confirmed that miR-26a-5p could directly target GSK3β. GSK3β overexpression significantly reversed the expression of cardiac hypertrophy-related markers including ANP, ACTA1 and MYH7. Immunofluorescence staining results demonstrated that miR-26a-5p promoted cardiac hypertrophy related protein α-actinin expression, and increased cell surface area in vitro and in vivo. Conclusion Our study revealed that miR-26a-5p promotes myocardial cell autophagy activation and cardiac hypertrophy by regulating GSK3β, which needs further research.

Lectin Staining of Peritoneal Mesothelial Cells in Vitro

1991 ◽  
Vol 11 (4) ◽  
pp. 307-316 ◽  
Author(s):  
J. Thomas Hjelle ◽  
Barbara T. Golinska ◽  
Diane C. Waters ◽  
Kevin R. Steidley ◽  
Marcia A. Miller ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Cell Surface ◽  
Lectin Binding ◽  
Mesothelial Cells ◽  
Peritoneal Mesothelial Cells ◽  
Lectin Staining ◽  
Intracellular Vesicles ◽  
Intracellular Fluorescence

A survey of lectin-binding specificities present on rodent and human mesothelial cells propagated and maintained in tissue culture was made using fluorescein isothiocynate conjugated (FITC) lectins. Rodent and human cells exhibited cell-associated fluorescence following exposure to the FITC-Iectins from C. ensiformis, T. vulgaris, A. hypogaea, E. cristagalli and B. simplicifolia, but not with lectins from G. max and D. biflorus. Rodent cells were also positive for FITC-M. pomifera lectin binding. Human, but not rodent, cells were positive for FITC T. purpureas lectin binding. Exposure of rabbit mesothelial cells in vitro to FITC-Iectins that bound to the cell surface resulted in the appearance of discrete loci of putatively intracellular fluorescence. Exposure of cells to ferritin-Iabelled T. vulgaris lectin at 37°C for as little as 7.5 minutes resulted in the appearance of ferritin-size particles in intracellular vesicles. These results demonstrate 1. the presence of lectinbinding sites in and on peritoneal mesothelial cells from rodents and humans and 2. a possible role of such sites in mediating the entry of lectin-Iike endogenous molecules into the vacuolar apparatus of these cells.

Compartmentalization of protein traffic in insulin-sensitive cells

1996 ◽  
Vol 271 (1) ◽  
pp. E1-E14 ◽  
Author(s):  
K. V. Kandror ◽  
P. F. Pilch
Keyword(s):  
Cell Surface ◽  
Physiological Role ◽  
Fat Cells ◽  
Protein Traffic ◽  
Glut 1 ◽  
Glut 4 ◽  
Factor Ii ◽  
Nutritional Needs

Insulin-sensitive cells, adipocytes and myocytes, translocate a number of intracellular proteins to the cell surface in response to insulin. Among these proteins are glucose transporters 1 and 4 (GLUT-1 and GLUT-4, respectively), receptors for insulin-like growth factor II (IGF-II)/mannose 6-phosphate (Man-6-P) and transferrin, the aminopeptidase gp 160, caveolin, and a few others. In the case of insulin-activated glucose transport, this translocation has been proven to be the major, if not the only regulatory mechanism of this process. It seems likely that the cell surface recruitment of the IGF-II/Man-6-P and transferrin receptors also serves the nutritional needs of cells, whereas the physiological role of the aminopeptidase gp160 remains uncertain. Analysis of the compartmentalization and trafficking pathways of translocatable proteins in fat cells identified more than one population of recycling vesicles, although all have identical sedimentation coefficients and buoyant densities in vitro. GLUT-4-containing vesicles include essentially all the intracellular GLUT-4, gp160, and the acutely recycling populations of receptors for IGF-II/Man-6-P and transferrin. Besides these proteins, which can be considered as vesicle “cargo”, GLUT-4-containing vesicles have other components, like secretory carrier-associated membrane proteins (SCAMP), Rab(s), and vesicle-associated membrane protein (VAMP)/cellubrevin, which are ubiquitous to secretory vesicles and granules from different tissues. GLUT-1 and caveolin are excluded from GLUT-4-containing vesicles and form different vesicular populations of unknown polypeptide composition. In skeletal muscle, two independent populations of GLUT-4-containing vesicles are found, insulin sensitive and exercise sensitive, which explains the additive effect of insulin and exercise on glucose uptake. Both vesicular populations are similar to each other and to analogous vesicles in fat cells.

scholarly journals The role of cell surface markers and enamel matrix derivatives on human periodontal ligament mesenchymal progenitor responses in vitro

Biomaterials ◽  
2011 ◽  
Vol 32 (30) ◽  
pp. 7375-7388 ◽  
Author(s):  
Philippe Kémoun ◽  
Stan Gronthos ◽  
Malcolm L. Snead ◽  
Jacqueline Rue ◽  
Bruno Courtois ◽  
...  
Keyword(s):  
Cell Surface ◽  
Periodontal Ligament ◽  
Surface Markers ◽  
Cell Surface Markers ◽  
Enamel Matrix ◽  
Enamel Matrix Derivatives ◽  
Matrix Derivatives

The role of murine cell surface galactosyltransferase in trophoblast: Laminin interactions in vitro

1990 ◽  
Vol 141 (2) ◽  
pp. 254-261 ◽  
Author(s):  
Linda Romagnano ◽  
Bruce Babiarz
Keyword(s):  
Cell Surface ◽  
Murine Cell

Transformation by the v-fms oncogene product: role of glycosylational processing and cell surface expression

1985 ◽  
Vol 5 (12) ◽  
pp. 3467-3475
Author(s):  
E J Nichols ◽  
R Manger ◽  
S Hakomori ◽  
A Herscovics ◽  
L R Rohrschneider
Keyword(s):  
Cell Surface ◽  
Gene Product ◽  
Early Stage ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Sarcoma Virus ◽  
Complete Processing ◽  
Oncogene Protein

The effect of glycosylational-processing inhibitors on the synthesis, cell surface expression, endocytosis, and transforming function of the v-fms oncogene protein (gp140fms) was examined in McDonough feline sarcoma virus-transformed Fischer rat embryo (SM-FRE) cells. Swainsonine (SW), a mannosidase II inhibitor, blocked complete processing, but an abnormal v-fms protein containing hybrid carbohydrate structures was expressed on the cell surface. SW-treated SM-FRE cells retained the transformed phenotype. In contrast, two glucosidase I inhibitors (castanospermine [CA] and N-methyl-1-deoxynojirimycin [MdN]) blocked carbohydrate remodeling at an early stage within the endoplasmic reticulum and prevented cell surface expression of v-fms proteins. CA-treated SM-FRE cells reverted to the normal phenotype. Neither SW, CA, nor MdN affected either endocytosis or the tyrosine kinase activity associated with the v-fms gene product in vitro. These results demonstrate the necessity of carbohydrate processing for cell surface expression of the v-fms gene product and illustrate the unique ability to modulate the transformed state of SM-FRE cells with the glycosylational-processing inhibitors CA and MdN.

scholarly journals Involvement of LFA-1 in lymphoma invasion and metastasis demonstrated with LFA-1-deficient mutants.

1989 ◽  
Vol 108 (5) ◽  
pp. 1979-1985 ◽  
Author(s):  
F F Roossien ◽  
D de Rijk ◽  
A Bikker ◽  
E Roos
Keyword(s):  
Cell Surface ◽  
Surface Protein ◽  
Metastatic Potential ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Lymphocyte Function ◽  
Lymphoma Cells ◽  
Mutant Cells

Lymphocyte function-associated antigen-1 (LFA-1) is a leukocyte and lymphoma cell surface protein that promotes intercellular adhesion. We have previously shown that the invasion of hepatocyte cultures by lymphoma cells is inhibited by anti-LFA-1 antibodies (Roos, E., and F. F. Roossien. 1987. J. Cell Biol. 105:553-559). In addition, we now report that LFA-1 is also involved in invasion of lymphoma cells into fibroblast monolayers. To investigate the role of LFA-1 in metastasis of these lymphoma cells, we have generated mutants that are deficient in LFA-1 cell surface expression because of impaired synthesis of either the alpha or beta subunit precursor of LFA-1. We identified at least three distinct mutant clones. The invasive potential of the mutant cells in vitro, in both hepatocyte and fibroblast cultures, was considerably lower than that of parental cells. The metastatic potential of the mutants was much reduced, indicating that LFA-1 expression is required for efficient metastasis formation by certain lymphoma cells.

Biosynthesis of N-Acetylneuraminic Acid in Cells Lacking UDP-N-Acetylglucosamine 2-Epimerase/ N-Acetylmannosamine Kinase

2001 ◽  
Vol 382 (2) ◽  
pp. 291-297 ◽  
Author(s):  
Stephan Hinderlich ◽  
Markus Berger ◽  
Oliver T. Keppler ◽  
Michael Pawlita ◽  
Werner Reutter
Keyword(s):  
Cell Surface ◽  
Cell Line ◽  
Kinase Activity ◽  
Gel Filtration ◽  
Acetylneuraminic Acid ◽  
Biological Recognition ◽  
Functionally Impaired ◽  
Cell Surface Glycoconjugates

Abstract The first two steps in mammalian biosynthesis of Nacetylneuraminic acid, an important carbohydrate moiety in biological recognition systems, are performed by the bifunctional enzyme UDPNacetylglucosamine 2-epimerase/Nacetylmannosamine kinase. A subclone of the human B lymphoma cell line BJAB K20, lacking UDPNacetylglucosamine 2- epimerase/Nacetylmannosamine kinase mRNA as well as epimerase activity, displayed hyposialylated, functionally impaired cell surface glycoconjugates. Here we show that this cell line surprisingly still retains Nacetylmannosamine kinase activity. A gel filtration analysis of BJAB K88 control cells, which express UDPNacetylglucosamine 2-epimerase/Nacetylmannosamine kinase, revealed two Nacetylmannosamine kinase activity peaks, one coeluting with UDPNacetylglucosamine 2-epimerase activity and one coeluting with Nacetylglucosamine kinase. For this enzyme previous studies already showed ManNAc kinase activity in vitro. In contrast, the hyposialylated BJAB K20 subclone displayed only the Nacetylmannosamine kinase peak, comigrating with Nacetylglucosamine kinase. The CMPNacetylneuraminic acid content of both K88 and K20 cells and the sialylation of cell surface glycoconjugates of K20 cells could be significantly increased by supple menting the medium with Nacetylmannosamine. This Nacetylmannosamineinduced increase was drastically reduced by cosupplementation with Nacetylglucosamine only in K20 cells. We therefore propose the phosphorylation of Nacetylmannosamine as a hitherto unrecognized role of Nacetylglucosamine kinase in living cells.

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