Plasma Membrane and Cell Cortex Interactions in Lymphocyte Functions

Loor, Francis

doi:10.1016/s0065-2776(08)60194-7

Cited by 65 publications

(13 citation statements)

References 598 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Exosomes [12] are another type of vesicle that is shed from cells, but these arise from intracellular multivesicular bodies; thus, the mode of formation is distinct from a pinching-off process, and exosomes are much smaller than CSVs. In the early studies of Ab capping on the lymphocyte cell surface, shedding was routinely stated to be an alternative fate of the cap, but internalization was the major pathway [13,14] and structures similar to CSVs were not described. Moreover, these early studies utilized primarily Abs to surface Ig, which were not delivered to CSVs in our experiments [1].…”

Section: Discussionmentioning

confidence: 99%

Characterization of antibody-containing vesicles shed from B-lymphoma cell lines: exposure of annexin V binding sites

Michel¹,

Abu‐Asab²,

Tsokos³

et al. 2006

Leukemia & Lymphoma

View full text Add to dashboard Cite

Antibodies (Abs) to CD20 or HLA-DR, after binding to the B-lymphoma cell line RL following an overnight incubation at 37°C, accumulate in the form of shed vesicles, which develop in the center of the cell clusters that are spontaneously formed by this cell line. These vesicles coalesce into fairly stable large structures, which we refer to as conglomerates of shed vesicles (CSVs). In the present study, we have extended our previous investigations into the nature of this material. Electron microscopy revealed a conglomerate of heterogeneous vesicles, which looked like pinched-off cytoplasmic projections. CSVs developed similarly either with or without Ab, demonstrating that CSV production is a spontaneous process that incorporates bound Abs if they are present. Before delivery to CSVs, the Abs capped on the cell surface. CSVs had high expression of annexin V binding sites, which are phagocytic signals that are exposed on damaged cells. For CSVs that were cell bound, which are frequently observed, the annexin V binding sites were only in the CSVs, and not on the surface of the intact cell. Although all CSVs contained both Abs and annexin V binding sites, the precise distribution of these two ligands was generally different. Annexin V binding sites were present on caps as well as on CSVs, and appear as soon as caps are formed. In cells incubated with anti-HLA-DR, CD20 was delivered to the CSVs together with HLA-DR, suggesting an association between these two molecules. CSVs prepared with anti-HLA-DR, but not CSVs prepared with anti-CD20, contained considerable numbers of nuclear fragments, identified by propidium iodide staining.

show abstract

Section: Discussionmentioning

confidence: 99%

Characterization of antibody-containing vesicles shed from B-lymphoma cell lines: exposure of annexin V binding sites

Michel¹,

Abu‐Asab²,

Tsokos³

et al. 2006

Leukemia & Lymphoma

View full text Add to dashboard Cite

show abstract

“…Cytoskeletal components, such as microtubules and microfilaments, are involved in many cellular functions, i.e., cell movement, phagocytosis, secretion, mitosis, receptor distribution and some membrane-linked physiologic processes. Ca2+ plays an essential role in these functions (4,5,15,29). Zn2+ may also affect these components, directly or indirectly, by influencing Ca2+ metabolism in cells and changing the excitability of the plasma membrane, which could also explain its effect on hormone metabolism although the exact mechanism whereby this occurs in the testis is not clear.…”

Section: Discussionmentioning

confidence: 99%

Effect of Zinc Ion on Human Chorionic Gonadotropin-Stimulated in Vitro Production of Cyclic AMP and Testosterone by Rat Testis

et al. 1984

View full text Add to dashboard Cite

SummaryThis study explores the effects of several divalent metal ions on the in vitro production of cyclic AMP, cyclic GMP, and testosterone by rat testicular tissue and on the amount of binding of ['251]human chorionic gonadotropin (hCG) in the testis. Zn2+ at concentrations of to M enhanced the hCG-stimulated production of cyclic AMP and testosterone, but only in the presence of Ca2+. ['251]hCG binding to rat testicular tissue was not affected by Zn2+. Cu2+, Ni2+, Co2+, and MnZ+ did not increase cyclic AMP or testosterone production in concentrations of lo-' to M and even inhibited them at a high concentration M). Cyclic GMP production was not affected by these divalent ions. These results suggest that Zn2+ may play an important role in rat testicular steroidogenesis. Abbreviations hCG, human chorionic gonadotropin KRBB, Krebs Ringer bicarbonate buffer PBS, phosphate buffered saline Trace metal ions are known to influence hormones at several stages of action, including hormone secretion and activity and binding to target tissue. Conversely, hormones influence trace metal ion metabolism at several levels, including excretion and transport of ions (9). Zinc ion plays an important role in growth and sexual development. A deficiency of zinc not only reduces zinc levels in the reproductive tissues but also impairs the responsiveness of the Leydig cells to gonadotropins, and thus may cause primary hypogonadism in humans as well as in experimental animals (1, 14, 28). Furthermore, constitutionally short boys at Tanner stages 1 and 2 have lower zinc levels in their serum and hair and lower serum testosterone levels than those at Tanner stages 3 to 5 (3). These results suggest that the relative testosterone deficiency in constitutional growth delay may result in decreased zinc levels, which in turn could cause a further delay in sexual development and growth.Recent studies indicate that the uptake of hCG in the testes of zinc-injected rats is significantly higher than that in controls (1 1, 12) and that Zn2+ affects adenylate cyclase activity in bovine and human sperm (2, 8) and liver (16). We investigated that the effects of various divalent metal ions, including Zn2+, on cyclic AMP, cyclic GMP, and testosterone production stimulated by hCG and the effect of Zn2+ on the binding of [1251]hCG to rat testicular tissue in vitro. MATERIALS AND METHODSMale Wistar rats were reared in individual stainless steel cages and fed an adequate amount of zinc (43 ppm) ad libitum for 4 wk before the study. Deionized water was also provided ad libitum. The mean weight was 242 + 16 g at the time of study.They were anesthetized with ether. Both testes were removed, decapsulated, and sectioned into 50-mg slices from one rat for each experiment. Four tissue slices from each rat were used for each concentration of each metal in the presence or absence of hCG. Studies were repeated at least once and similar results were obtained in each metal experiment. This paper describes one of three similar zinc experiments. Sixteen rats were used in al...

show abstract

“…The role of the cytoskeleton in the polarization response was studied by prior treatment of the cells with cytochalasin B, which disrupts microfilaments, and vinblastine sulphate which disrupts microtubules (14). The decreased fluorescence polarization after PHA stimulation was not observed if mouse spleen cells were pre-incubated for 3 h with cytochalasin B (Sigma Chemical Co., St Louis, MO, USA; Table 4).…”

Section: Cytoskeleton-disrupting Agentsmentioning

confidence: 99%

Analysis of early lymphocyte activation events by fluorescence polarization flow cytometry

Dimitropoulos

Rolland

1988

Immunol Cell Biol

View full text Add to dashboard Cite

Summary After shorl-term (up to 4 h) stimulation with mitogen or antigen, lymphocytes were incubated with fluorescein diacetate and the polarization of fluorescence from intracellular fluorescein was measured on a specially adapted FACS II. This flow cytofluorimetric method to assay early changes in activated lymphocytes gave a reproducible response to the mitogens phytohaemagglutinin (PHA). concanavalin-A and the monoclonal antibody OKT3, recognized at 1 h by decreased polarization. A response by immune spleen ceils to the antigen dinitrophenyl-ovalbumin was revealed at 4 h. The calcium ionophore A23187 induced an increase in polarization after only 10 min. The PHA polarization response was shown to be dependent on PHA binding, PHA dose, T cells, calcium ions and an intact cytoskeleton. The cellular events monitored by the polarization change are presumably altered fluidity of the probe's microenvironment due to conformational change in macromolecules to which the probe has bound or to dissociation of the probe into the aqueous phase. The fluorescein fluorescence polarization assay is a reliable and sensitive monitor of early lymphocyte activation events and. coupled with the use of a flow cytometer, permits study of particular subpopulations of responding cells.

show abstract

Plasma Membrane and Cell Cortex Interactions in Lymphocyte Functions

Cited by 65 publications

References 598 publications

Characterization of antibody-containing vesicles shed from B-lymphoma cell lines: exposure of annexin V binding sites

Characterization of antibody-containing vesicles shed from B-lymphoma cell lines: exposure of annexin V binding sites

Effect of Zinc Ion on Human Chorionic Gonadotropin-Stimulated in Vitro Production of Cyclic AMP and Testosterone by Rat Testis

Analysis of early lymphocyte activation events by fluorescence polarization flow cytometry

Contact Info

Product

Resources

About