scholarly journals INDEPENDENCE OF H-2K AND H-2D ANTIGENIC DETERMINANTS ON THE SURFACE OF MOUSE LYMPHOCYTES

1973 ◽  
Vol 137 (2) ◽  
pp. 511-526 ◽  
Author(s):  
Catherine Neauport-Sautes ◽  
Frank Lilly ◽  
Danielle Silvestre ◽  
François M. Kourilsky
Keyword(s):  
Cell Surface ◽  
Fluorescein Isothiocyanate ◽  
Antigenic Determinants ◽  
Membrane Structures ◽  
F1 Hybrid ◽  
Living Mouse ◽  
Lymph Node Cells ◽  
In Cis ◽  
Induced Aggregation ◽  
Mouse Lymphocytes

At 37°C, fluorescein-conjugated anti-H-2 alloantibodies specifically induce, at the surface of living mouse lymphocytes, the redistribution of the corresponding H-2 antigens, which cluster as patches and sometimes single caps at one pole of the cell. This aggregation is inhibited at 0°C and the H-2 antigens, stained by fluorescent antibodies in the cold, appear evenly spread over the cell surface. This phenomenon was used to define the relationships between the membrane structures bearing the antigens coded by the H-2K and the H-2D genes of the H-2 region. Monospecific anti-H-2 antibodies coupled to either tetramethyl rhodamine isothiocyanate or fluorescein isothiocyanate were used to induce the redistribution of H-2D and H-2K antigens of the H-2b and H-2k haplotype at the surface of lymph node cells from homozygous and F1 hybrid mice. It was observed that the diffuse distribution of H-2K antigens labeled at 0°C was not affected by the prior antibody-induced aggregation of H-2D antigens and vice versa. The results were the same for H-2 antigens governed by genes located either in cis or in trans position. These data indicate that the H-2K and H-2D antigens migrate independently at the cell surface, and suggest that the gene products from the D and the K end of the H-2 region are expressed on independent molecules or structures at the cell membrane.

scholarly journals Antigen-induced aggregation and modulation of receptors on hapten-specific B lymphocytes.

1976 ◽  
Vol 143 (3) ◽  
pp. 511-528 ◽  
Author(s):  
G J Nossal ◽  
J E Layton
Keyword(s):  
Cell Surface ◽  
B Lymphocytes ◽  
B Lymphocyte ◽  
Lymphocyte Activation ◽  
Fluorescein Isothiocyanate ◽  
Receptor Occupancy ◽  
Surface Receptors ◽  
Continuous Presence ◽  
Induced Aggregation

Mouse spleen cells were subjected to a fractionation procedure designed to enrich for 4-hydroxy-3-iodo-5-nitro-phenylacetyl (NIP)- or DNP-specific B lymphocytes, which depended on adherence of specific cells to a layer of hapten-gelatin at 4 degrees C, recovery of bound cells by melting, and digestion of adherent antigen by collagenase. A population of cells resulted which contained 90% typical B cells and 37% of cells capable of binding a fluorescent, haptenated polymeric protein. Fractionated cells were reacted in vitro with fluorescent conjugates of the specific haptens with polymerized flagellin [NIP-polymerized flagellin (POL)-tetramethylrhodamine isothiocyanate conjugate or DNP-POL-fluorescein isothiocyanate conjugate] under a variety of conditions, with the aim of investigating the behavior of Ig receptors on B lymphocytes after exposure to antigen; Experiments were performed with immunogenic and tolerogenic concentrations of antigen. Furthermore, four experimental designs were used, namely: (a) brief labeling with fluorescent antigen followed by culture without antigen (pulse design); (b) culture in the continuous presence of fluorescent antigen (continuous-labeling design); (c) culture in the continuous presence of nonlabeled antigen followed by labeling of unoccupied receptors by fluorescent antigen (receptor status design); and (d) culture with nonlabeled antigen for 2 h followed by incubation without further antigen for 20 h and labeling with fluorescent antigen (modulation design). Further insight into receptor occupancy and distribution was gained by the use of fluorescent antihapten and antiglobulin reagents. It was found that both immunogenic and tolerogenic antigen concentrations caused rapid patching and capping of the receptors to which they attached, followed by endocytosis and probably some shedding of Ig receptors. However, a proportion of cells continued to bear some cell surface antigen for 24 h. The immunogenic antigen concentration failed to completely remove the receptor coat from the cell surface. At all stages of immunogenesis, plentiful unoccupied receptors could be demonstrated. The tolerogenic concentration nearly saturated available receptors, and in its continuous presence, only few unoccupied or antigen-occupied surface receptors could be detected after 24 h of culture. Experiments of the modulation design showed that brief incubation with the tolerogenic concentration appeared to suppress receptor resynthesis, as few new receptors could be demonstrated after 20 h of further culture without antigen. Experiments were performed to determine whether fractionated cells prepared from spleens of 8-day-old mice showed an unusual tendency for modulation, even with immunogenic antigen concentrations. They were found to behave essentially like adult fractionated cells. The results are discussed in the framework of current theories of B-lymphocyte activation and tolerization.

Glycoconjugates on the surface of spores of the pathogenic fungus Phytophthora cinnamomi studied using fluorescence and electron microscopy and flow cytometry

1990 ◽  
Vol 36 (3) ◽  
pp. 183-192 ◽  
Author(s):  
A. R. Hardham ◽  
E. Suzaki
Keyword(s):  
Flow Cytometry ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Phytophthora Cinnamomi ◽  
Pathogenic Fungus ◽  
Fluorescein Isothiocyanate ◽  
Pathogenic Fungi ◽  
Surface Flow ◽  
Soybean Agglutinin ◽  
Binding Material

Glycoconjugates on the surface of zoospores and cysts of the pathogenic fungus Phytophthora cinnamomi have been studied using fluorescein isothiocyanate labelled lectins for fluorescence microscopy and flow cytometry, and ferritin- and gold-labelled lectins for ultrastructural analysis. Of the five lectins used, only concanavalin A (ConA) binds to the surface of the zoospores, including the flagella and water expulsion vacuole. This suggests that of accessible saccharides, glucosyl or mannosyl residues predominate on the outer surface of the zoospore plasma membrane. Early in encystment, a system of flat disc-like cisternae, which underlie the zoospore plasma membrane, vesiculate. These and other small peripheral vesicles quickly disappear. After the induction of encystment, ConA is no longer localised close to the plasma membrane but binds to material loosely associated with the cell surface. Quantitative measurements by flow cytometry indicate that the ConA-binding material is gradually lost from the cell surface. The cyst wall is weakly labelled, but the site of germ tube emergence stains intensely. During the first 2 min after the induction of encystment, material that binds soybean agglutinin, Helix pommatia agglutinin, and peanut agglutinin appears on the surface of the fungal cells. The distribution of this material, rich in galactosyl or N-acetyl-D-galactosaminosyl residues, is initially patchy, but by 5 min the material evenly coats most of the cell surface. Labelling of zoospores in which intracellular sites are accessible indicates that the soybean agglutinin binding material is stored in vesicles that lie beneath the plasma membrane. Quantitation of soybean agglutinin labelling shows that maximum binding occurs 2–3 min after the induction of encystment. Key words: cell surface, flow cytometry, lectins, pathogenic fungi, Phytophthora cinnamomi.

scholarly journals Localization of CD4 and CCR5 in Living Cells

2003 ◽  
Vol 77 (8) ◽  
pp. 4985-4991 ◽  
Author(s):  
Carolyn M. Steffens ◽  
Thomas J. Hope
Keyword(s):  
Human Immunodeficiency Virus ◽  
High Resolution ◽  
Cell Membrane ◽  
Cell Surface ◽  
Fluorescent Microscopy ◽  
Living Cells ◽  
Stable Complex ◽  
Membrane Structures ◽  
Virus Fusion ◽  
Immunodeficiency Virus

ABSTRACT The events preceding human immunodeficiency virus fusion and entry are influenced by the concentration and distribution of receptor and coreceptor molecules on the cell surface. However, the extent to which these proteins colocalize with one another in the cell membrane remains unclear. Using high-resolution deconvolution fluorescent microscopy of living cells, we found that both CD4 and CCR5 accumulate in protruding membrane structures containing actin and ezrin. Although CD4 and CCR5 extensively colocalize in these structures, they do not exist in a stable complex.

scholarly journals EVIDENCE FOR IDENTITY OR CLOSE ASSOCIATION OF THE Fc RECEPTOR OF B LYMPHOCYTES AND ALLOANTIGENS DETERMINED BY THE Ir REGION OF THE H-2 COMPLEX

1974 ◽  
Vol 140 (3) ◽  
pp. 779-796 ◽  
Author(s):  
Howard B. Dickler ◽  
David H. Sachs
Keyword(s):  
B Lymphocytes ◽  
B Lymphocyte ◽  
Close Association ◽  
Surface Membrane ◽  
Fc Receptor ◽  
F1 Hybrid ◽  
Ia Antigens ◽  
Series Of Experiments ◽  
Mouse Lymphocytes ◽  
Mouse Antibody

Immunoglobulin complexes, composed of heat-aggregated human Ig, were shown to bind to mouse B lymphocytes of a variety of strains, but not to either thymocytes or thymus-derived (T) lymphocytes under a variety of conditions. It was shown that this binding was not due to either natural human antibodies against mouse nor to nonspecific binding of human Ig by mouse lymphocytes. Such complexes were shown to bind to the same sites which bind mouse antibody-antigen complexes. This site is known as the Fc receptor. The binding of Ig complexes to mouse B lymphocytes was markedly inhibited by pretreatment of the lymphocytes with anti-H-2 antisera. A series of experiments indicated the specificity of this result, including the fact that this inhibition was shown not to be due to the artifact of shedding of H-2 antibody-antigen complexes, nor to nonspecific steric inhibition. The antibodies within anti-H-2 antisera which were responsible for this inhibition were specific for alloantigens associated with the Ir region of the H-2 complex (Ia antigens). Antiserum specific for these Ia antigens produced inhibition, whereas antisera specific for antigens determined by the K or D regions of the H-2 complex did not. Evidence was obtained using F1 hybrid cells that at least some Ia antigens of both parental types are expressed on every B lymphocyte (i.e. codominant expression). These data indicate that the Fc receptor and a series of alloantigens controlled by the Ir region of the H-2 complex are identical or closely associated on the B-lymphocyte surface membrane. This observation may have implications for the mechanism of control of the immune response.

scholarly journals Truncated mu (mu') chains in murine IgM. Evidence that mu' chains lack variable regions.

1985 ◽  
Vol 162 (6) ◽  
pp. 1862-1877 ◽  
Author(s):  
R Marks ◽  
M J Bosma
Keyword(s):  
Bone Marrow ◽  
Lymph Node ◽  
Molecular Mass ◽  
Tumor Cells ◽  
Isoelectric Focusing ◽  
Bone Marrow Cells ◽  
Normal Serum ◽  
Antigenic Determinants ◽  
Variable Regions ◽  
Lymph Node Cells

Secreted IgM was shown to contain truncated mu (mu') chains with an apparent molecular mass of approximately 55 kD. The estimated percentage of IgM heavy (H) chains in the mu' form ranged from less than or equal to 1% in the case of one tumor IgM protein (104E) to greater than or equal to 30% in normal serum IgM. Serum mu' chains lacked antigenic determinants characteristic of immunoglobulin variable regions and showed a restricted isoelectric focusing pattern compared with that of conventional mu chains. Intracellular mu' chains were readily detected in bone marrow cells but not in spleen or lymph node cells; mu' chains were also detected in IgM-producing tumor cells and in a hybridoma cell line that deleted its productive mu allele. These results predict irregularities in IgM structure and recall an old controversy concerning the valence of IgM molecules.

scholarly journals Topological and Structural Plasticity of the Single Ig Fold and the Double Ig Fold Present in CD19

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1290 ◽  
Author(s):  
Philippe Youkharibache
Keyword(s):  
Cell Surface ◽  
3D Structure ◽  
Cell Surface Receptor ◽  
Cell Surface Receptors ◽  
Structural Domain ◽  
Surface Receptors ◽  
Surface Receptor ◽  
In Trans ◽  
In Cis ◽  
Ig Domain

The Ig fold has had a remarkable success in vertebrate evolution, with a presence in over 2% of human genes. The Ig fold is not just the elementary structural domain of antibodies and TCRs, it is also at the heart of a staggering 30% of immunologic cell surface receptors, making it a major orchestrator of cell–cell interactions. While BCRs, TCRs, and numerous Ig-based cell surface receptors form homo- or heterodimers on the same cell surface (in cis), many of them interface as ligand-receptors (checkpoints) on interacting cells (in trans) through their Ig domains. New Ig-Ig interfaces are still being discovered between Ig-based cell surface receptors, even in well-known families such as B7. What is largely ignored, however, is that the Ig fold itself is pseudosymmetric, a property that makes the Ig domain a versatile self-associative 3D structure and may, in part, explain its success in evolution, especially through its ability to bind in cis or in trans in the context of cell surface receptor–ligand interactions. In this paper, we review the Ig domains’ tertiary and quaternary pseudosymmetries, with particular attention to the newly identified double Ig fold in the solved CD19 molecular structure to highlight the underlying fundamental folding elements of Ig domains, i.e., Ig protodomains. This pseudosymmetric property of Ig domains gives us a decoding frame of reference to understand the fold, relate all Ig domain forms, single or double, and suggest new protein engineering avenues.

IgG plasma cells display a unique spectrum of leukocyte adhesion and homing molecules

Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 2905-2912 ◽  
Author(s):  
Gregory H. Underhill ◽  
Heather A. Minges-Wols ◽  
Jamie L. Fornek ◽  
Pamela L. Witte ◽  
Geoffrey S. Kansas
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
Messenger Rna ◽  
Plasma Cells ◽  
Leukocyte Adhesion ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Leukocyte Function ◽  
Lymph Node Cells ◽  
Cell Adhesion Molecule 1

Abstract Long-lived antibody-secreting plasma cells are formed in the secondary lymphoid organs and subsequently home to the bone marrow, although the mechanisms that control this migration remain primarily unknown. In this study, we show that IgG plasma cells constitute a significant fraction of cervical lymph node cells from older mice deficient in both E- and P-selectin (E/P−/−), and that these cells can be prospectively isolated by phenotype. These IgG plasma cells were polyclonal, cytoplasmic Ig+, spontaneously secreted antibody, were in the G0/G1 phase of the cell cycle, and failed to express multiple B-cell surface markers. The plasma cells exhibited up-regulated cell surface expression of multiple adhesion molecules, including α4 and leukocyte function-associated antigen 1 (LFA-1) integrins, CD44, and P-selectin glycoprotein ligand 1 (PSGL-1). IgG plasma cells bound to vascular cell adhesion molecule 1 (VCAM-1) significantly better than IgM+B cells, indicating that the α4 integrins were constitutively active. A subset of IgG plasma cells also bound hyaluronic acid, the ligand for CD44. In addition, the IgG plasma cells interacted strongly with E-selectin, but poorly with P-selectin, despite elevated levels of PSGL-1 protein. The preferential interaction of plasma cells with E-selectin, but not P-selectin, correlated with elevated α1,3-fucosyltransferase-VII messenger RNA levels, but selective down-regulation of core 2 β1-6-N-glucosaminyltransferase levels, compared to B cells. These results demonstrate a unique adhesion profile for murine IgG plasma cells. Furthermore, the E/P−/− mice represent a novel system to isolate and purify significant numbers of primary IgG plasma cells.

Aggregative Behaviour of Embryonic Chick Cells in the Presence of Anti-Bodies Directed Against Actomyosins

1971 ◽  
Vol 9 (1) ◽  
pp. 103-122
Author(s):  
R. B. KEMP ◽  
B. M. JONES ◽  
U. GRÖSCHEL-STEWART
Keyword(s):  
Smooth Muscle ◽  
Cell Surface ◽  
Striated Muscle ◽  
Calf Serum ◽  
Fluorescein Isothiocyanate ◽  
Muscle Cells ◽  
Cell Aggregation ◽  
Inhibitory Effect ◽  
Human Umbilical Cord ◽  
Gyratory Shaker

Skeletal muscle and liver tissue from 9-day-old chick embryos were dissociated into separate cells using 0.25 % (w/v) crude trypsin. The effect of rabbit anti-actomyosin sera on the aggregation of these cells was estimated by the gyratory shaker and turbidimetric methods. Studies were also undertaken on the ability of fluorescein isothiocyanate-labelled rabbit anti-uterine actomyosin serum (FITC-labelled anti-UAM) to stain the cell surface and on the type specificity and species specificity of rabbit anti-chicken actomyosin sera. Antisera against chicken gizzard smooth-muscle actomyosin (anti-GAM) and against chicken pectoralis striated muscle actomyosin (anti-PAM) both gave single precipitin bands with their respective actomyosins on diffusion through agar. The antisera neither reacted with their heterologous actomyosin nor with gizzard tropomyosin; they were type-specific. Serial sections of human cervix were stained in a similar pattern with both anti-UAM and anti-GAM, showing that anti-smooth muscle actomyosin sera were not species-specific. The fibrocytes of the human umbilical cord and human platelets were stained by FITC-labelled anti-UAM serum but not by labelled anti-human PAM. The aggregation of muscle and liver cells over a 24-h period in the presence of antisera against human or chicken PAM was not significantly different from the controls incubated on a gyratory shaker in Eagle's minimum essential medium (MEM) containing 10% (v/v) rabbit non-immunized serum (NIS) or calf serum. However, anti-UAM and anti-GAM inhibited both the rate of aggregation of liver and muscle cells and the size of aggregates attained in 24 h. This effect could not be simulated with specific rabbit antisera against human plasma proteins. The globulin-enriched fraction of anti-GAM markedly inhibited the aggregation of liver and muscle cells in a range of concentrations between 50 and 500 µg per 2 x 106 cells/ml Eagle's MEM. In contrast, the aggregation of cells incubated with globulin-enriched anti-PAM was similar to the controls. The addition of anti-GAM globulins at 1 or 2 h to muscle cells rotated by the turbidimetric method reduced the aggregative competence of the cells over the remainder of a 4-h period. The possibility that the inhibitory effect of anti-UAM and anti-GAM on cell aggregation is due to impurities in the antisera or to a general reaction with cell surface ATPases is discussed but, in the light of evidence, rejected in favour of a reaction between the antisera and an actomyosin of the smooth-muscle type at the cell surface.

Amelioration of sperm immobilisation factor-induced infertility by bacterial antigenic determinants cross-reacting with spermatozoa

2019 ◽  
Vol 31 (3) ◽  
pp. 602 ◽  
Author(s):  
Deepali Thaper ◽  
Deepak K. Rahi ◽  
Vijay Prabha
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Molecular Mimicry ◽  
Fluorescein Isothiocyanate ◽  
Antigenic Determinants ◽  
Sperm Function ◽  
Contraceptive Effect ◽  
Normal Sperm ◽  
Ameliorative Effect ◽  
Human And Mouse

A strain of Staphylococcus aureus, capable of invitro immobilisation of human and mouse spermatozoa, was already present in our laboratory. Therefore, in the present study, the factor responsible (sperm immobilisation factor, SIF) was isolated and purified. It was found to compromise not only motility, but also viability, morphology and Mg2+-ATPase activity of mouse spermatozoa. Also, SIF (250μgmL−1), when administered intravaginally in female BALB/c mice before mating, showed 100% contraceptive effect. Moreover, fluorescein isothiocyanate-labelled SIF was also found to bind mouse spermatozoa and various motile as well as non-motile bacteria, indicating the presence of common SIF-binding receptors on spermatozoa and bacteria. Further, to demonstrate molecular mimicry, the amelioration of SIF-induced impairment of sperm function by a SIF-binding bacterial receptor was compelling. For this, the SIF-binding receptor from Escherichia coli (E-SBR) was purified and evaluated for its ameliorative effect on SIF-induced sperm impairment invitro and invivo. Interestingly, upon the addition of mouse spermatozoa to SIF pre-incubated with E-SBR, an ameliorative effect against SIF-induced impairment of sperm function could be observed through analysis of normal sperm parameters (motility, viability, morphology, Mg2+-dependent ATPase levels). E-SBR also blocked binding of labelled SIF to spermatozoa and bacteria and alleviated SIF-induced infertility in female BALB/c mice. This provided evidence for molecular similarities between bacteria and spermatozoa, owing to which anti-bacterial antibodies cross-reacting with spermatozoa might be produced and infertility might follow.

scholarly journals Immunohistochemical detection of Fc receptor. I. Light microscopic demonstration of Fc receptor by using soluble immune complexes of peroxidase-antiperoxidase immunoglobulin G.

1977 ◽  
Vol 25 (4) ◽  
pp. 252-258 ◽  
Author(s):  
G Itoh ◽  
S Miura ◽  
I Suzuki
Keyword(s):  
Cell Surface ◽  
Immunoglobulin G ◽  
Immune Complexes ◽  
Surface Characterization ◽  
Fc Receptor ◽  
Frozen Sections ◽  
Microscopic Demonstration ◽  
Lymph Node Cells ◽  
Soluble Immune Complexes ◽  
And Control

The mouse mesenteric lymph node cells (in the cell suspension and frozen sections) were incubated in the soluble immune complexes of peroxidase-antiperoxidase immunoglobulin G. After being washed, they were reacted with diaminobenzidine tetrahydrochloride. Light microscopically brown-colored granules were observed on the cell surface of a proportion of small lymphocytes. In frozen sections, a proportion of small lymphocytes were stained dark brown on the cell surface. Characterization and control experiments suggest that the binding of peroxidase-antiperoxidase immunoglobulin G to the cell surface is mediated by Fc receptor. Peroxidase-antiperoxidase immunoglobulin G, therefore, can be used as in indicator of Fc receptor.

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