scholarly journals THE RATE OF DIVISION OF ANTIBODY-FORMING CELLS DURING THE EARLY PRIMARY IMMUNE RESPONSE

1968 ◽  
Vol 127 (5) ◽  
pp. 983-1002 ◽  
Author(s):  
Donald A. Rowley ◽  
Frank W. Fitch ◽  
Donald E. Mosier ◽  
Susan Solliday ◽  
Lionel W. Coppleson ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Drug Treatment ◽  
Cell Cultures ◽  
Cell Types ◽  
Primary Immune Response ◽  
Spleen Cells ◽  
Sheep Erythrocytes ◽  
Cycle Times ◽  
Blocking Agents

Mitotic blocking agents, colchicine or Velban, were used to estimate cycle times of spleen cells which release hemolysin for sheep erythrocytes (plaque-forming cells). The cells were obtained either from rats immunized with sheep erythrocytes or from cultures of mouse spleen cells immunized in vitro with the same antigen. 2, 3, or 4 days after immunization, animals or cell cultures were treated with mitotic blocking agents for periods of time ranging from 2.5 to 7 hr; plaque-forming cells were then enumerated. Decreased numbers of plaque-forming cells were found after such treatment. The extent of reduction was a function of duration of the drug treatment and the method of immunization, but was independent of the time after immunization. The evidence presented is consistent with premises that: (a) plaque-forming cells in mitosis do not release sufficient antibody to be detected, (b) mitotic blocking agents, by arresting plaque-forming cells in metaphase, prevent not only detection of these cells but also the increase in number of plaque-forming cells which would have resulted from cell division, (c) mitotic blocking agents do not affect release of antibody by cells in interphase. Cell cycle times, based on the extent of reduction of plaque-forming cells per unit time of drug treatment, were estimated using a mathematical model appropriate for an exponentially increasing population of cells. Cell cycle times estimated using the mitotic blocking agents agreed well with cell doubling times calculated from the increase in plaque-forming cells occurring 1–4 days after immunization. Increased responses produced by higher antigen doses or treatment of immunized animals with an adjuvant resulted from an increased rate of division of responding cells and their progeny. The results are consistent with a cell selection theory of antibody formation. Antigenic stimulation causes relatively few cells to proliferate and to synthesize antibody; apparently the magnitude of the response is dependent primarily on the rate of division of responding cells. It is suggested on the basis of observations of in vitro-immunized cell cultures that the rate of division of responding cells may be dependent on the rate of interaction between two cell types, both of which are essential for the in vitro plaque-forming cell response.

scholarly journals CELL INTERACTIONS IN THE PRIMARY IMMUNE RESPONSE IN VITRO: A REQUIREMENT FOR SPECIFIC CELL CLUSTERS

1969 ◽  
Vol 129 (2) ◽  
pp. 351-362 ◽  
Author(s):  
Donald E. Mosier
Keyword(s):  
Immune Response ◽  
Cell Cultures ◽  
Primary Immune Response ◽  
Antigenic Determinants ◽  
Specific Cell ◽  
Spleen Cells ◽  
Sheep Erythrocytes ◽  
Cell Clusters ◽  
Immune Response In Vitro

Mouse spleen cells were found to associate in cell clusters during the primary immune response to sheep erythrocytes in vitro. About 10% of the cell clusters had the following unique properties; (a) they contained most, if not all, antibody-forming cells, (b) they contained only cells forming antibody to one antigen when cell cultures were immunized with two antigens, (c) the cells in clusters reaggregated specifically after dispersion, and (d) the specific reaggregation of clusters appeared to be blocked by antibody to the antigen. The integrity of cell clusters was required for the proliferation of antibody-forming cells, and prevention of clustering by mechanical means or by excess antibody blocked the immune response. Antibody and antigenic determinants on the surfaces of cells probably provide the basis for interaction. The unique microenvironment of cell clusters was essential for the primary immune response in vitro.

scholarly journals EFFECTS OF HYDROCORTISONE ON THE IN VITRO PRIMARY IMMUNE RESPONSE OF MOUSE SPLEEN CELLS TO SHEEP ERYTHROCYTES

1972 ◽  
Vol 25 (5) ◽  
pp. 345-353 ◽  
Author(s):  
MASANOBU SUGIMOTO ◽  
SHIN-ICHI TAMURA ◽  
TAKESHI KURATA ◽  
YASUYUKI EGASHIRA
Keyword(s):  
Immune Response ◽  
Primary Immune Response ◽  
Mouse Spleen ◽  
Spleen Cells ◽  
Sheep Erythrocytes

scholarly journals Tumor quiescence: elevating SOX2 in diverse tumor cell types downregulates a broad spectrum of the cell cycle machinery and inhibits tumor growth

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ethan P. Metz ◽  
Erin L. Wuebben ◽  
Phillip J. Wilder ◽  
Jesse L. Cox ◽  
Kaustubh Datta ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Cell Cycle Machinery

Abstract Background Quiescent tumor cells pose a major clinical challenge due to their ability to resist conventional chemotherapies and to drive tumor recurrence. Understanding the molecular mechanisms that promote quiescence of tumor cells could help identify therapies to eliminate these cells. Significantly, recent studies have determined that the function of SOX2 in cancer cells is highly dose dependent. Specifically, SOX2 levels in tumor cells are optimized to promote tumor growth: knocking down or elevating SOX2 inhibits proliferation. Furthermore, recent studies have shown that quiescent tumor cells express higher levels of SOX2 compared to adjacent proliferating cells. Currently, the mechanisms through which elevated levels of SOX2 restrict tumor cell proliferation have not been characterized. Methods To understand how elevated levels of SOX2 restrict the proliferation of tumor cells, we engineered diverse types of tumor cells for inducible overexpression of SOX2. Using these cells, we examined the effects of elevating SOX2 on their proliferation, both in vitro and in vivo. In addition, we examined how elevating SOX2 influences their expression of cyclins, cyclin-dependent kinases (CDKs), and p27Kip1. Results Elevating SOX2 in diverse tumor cell types led to growth inhibition in vitro. Significantly, elevating SOX2 in vivo in pancreatic ductal adenocarcinoma, medulloblastoma, and prostate cancer cells induced a reversible state of tumor growth arrest. In all three tumor types, elevation of SOX2 in vivo quickly halted tumor growth. Remarkably, tumor growth resumed rapidly when SOX2 returned to endogenous levels. We also determined that elevation of SOX2 in six tumor cell lines decreased the levels of cyclins and CDKs that control each phase of the cell cycle, while upregulating p27Kip1. Conclusions Our findings indicate that elevating SOX2 above endogenous levels in a diverse set of tumor cell types leads to growth inhibition both in vitro and in vivo. Moreover, our findings indicate that SOX2 can function as a master regulator by controlling the expression of a broad spectrum of cell cycle machinery. Importantly, our SOX2-inducible tumor studies provide a novel model system for investigating the molecular mechanisms by which elevated levels of SOX2 restrict cell proliferation and tumor growth.

scholarly journals Rapid proliferation of activated lymph node CD4+ T cells is achieved by greatly curtailing the duration of gap phases in cell cycle progression

2014 ◽  
Vol 19 (4) ◽  
Author(s):  
Takuya Mishima ◽  
Shoko Toda ◽  
Yoshiaki Ando ◽  
Tsukasa Matsunaga ◽  
Manabu Inobe
Keyword(s):  
Cell Cycle ◽  
Immune Response ◽  
T Cells ◽  
Cd4 T Cells ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Cycle Times ◽  
Peripheral T Cells ◽  
G0 Phase

AbstractPeripheral T cells are in G0 phase and do not proliferate. When they encounter an antigen, they enter the cell cycle and proliferate in order to initiate an active immune response. Here, we have determined the first two cell cycle times of a leading population of CD4+ T cells stimulated by PMA plus ionomycin in vitro. The first cell cycle began around 10 h after stimulation and took approximately 16 h. Surprisingly, the second cell cycle was extremely rapid and required only 6 h. T cells might have a unique regulatory mechanism to compensate for the shortage of the gap phases in cell cycle progression. This unique feature might be a basis for a quick immune response against pathogens, as it maximizes the rate of proliferation.

scholarly journals Differential regulation of spleen cell-mediated eosinophil and neutrophil-macrophage production

Blood ◽  
1980 ◽  
Vol 55 (3) ◽  
pp. 489-493 ◽  
Author(s):  
SH Bartelmez ◽  
WH Dodge ◽  
DA Bass
Keyword(s):  
Growth Factor ◽  
Contrast Media ◽  
Spleen Cell ◽  
Trichinella Spiralis ◽  
Cell Types ◽  
Differential Regulation ◽  
Spleen Cells ◽  
Secretory Products ◽  
Kinetics Of

Abstract Nonadherent spleen cells of mice infected with Trichinella spiralis released growth stimulatory factors (GSFs) in vitro when challenged with excretory/secretory products of muscle stage larvae. The assay of GSF was based on proliferation of normal, nonadherent syngeneic marrow cells in liquid tube cultures. Media conditioned for 1 day by challenged spleen cells stimulated eosinophil production but failed to stimulate production of other cell types. In contrast, media conditioned for 5 days supported eosinophil, neutrophil, and macrophage production. The kinetics of cell production were also different. Eosinophil production started within 1 day, reached a peak at day 2, and was down to control levels by day 4. In contrast, neutrophil/macrophage production began between 2 and 4 days and reached a peak at 6--8 days. The short duration of eosinophil production was evidently due to depletion of growth-factor-responsive cells.

scholarly journals Single-Cell Techniques Using Chromosomally Tagged Fluorescent Bacteria To Study Listeria monocytogenes Infection Processes

2010 ◽  
Vol 76 (11) ◽  
pp. 3625-3636 ◽  
Author(s):  
Damien Balestrino ◽  
M�lanie Anne Hamon ◽  
Laurent Dortet ◽  
Marie-Anne Nahori ◽  
Javier Pizarro-Cerda ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Listeria Monocytogenes ◽  
Single Cell ◽  
Fluorescent Proteins ◽  
Cell Types ◽  
Intracellular Replication ◽  
Infectious Process ◽  
Infection Processes

ABSTRACT Listeria monocytogenes is a Gram-positive facultative intracellular pathogen which invades different cell types, including nonphagocytic cells, where it is able to replicate and survive. The different steps of the cellular infectious process have been well described and consist of bacterial entry, lysis of the endocytic vacuole, intracellular replication, and spreading to neighboring cells. To study the listerial infectious process, gentamicin survival assays, plaque formation, and direct microscopy observations are typically used; however, there are some caveats with each of these techniques. In this study we describe new single-cell techniques based on use of an array of integrative fluorescent plasmids (green, cyan, and yellow fluorescent proteins) to easily, rapidly, and quantitatively detect L. monocytogenes in vitro and in vivo. We describe construction of 13 integrative and multicopy plasmids which can be used for detecting intracellular bacteria, for measuring invasion, cell-to-cell spreading, and intracellular replication, for monitoring in vivo infections, and for generating transcriptional or translational reporters. Furthermore, we tested these plasmids in a variety of epifluorescence- and flow cytometry-based assays. We showed that we could (i) determine the expression of a particular promoter during the cell cycle, (ii) establish in one rapid experiment at which step in the cell cycle a particular mutant is defective, and (iii) easily measure the number of infected cells in vitro and in mouse organs. The plasmids that are described and the methods to detect them are new powerful tools to study host-Listeria interactions in a fast, robust, and high-throughput manner.

scholarly journals Immature megakaryocytes in the mouse: physical characteristics, cell cycle status, and in vitro responsiveness to thrombopoietic stimulatory factor

Blood ◽  
1982 ◽  
Vol 59 (3) ◽  
pp. 569-575 ◽  
Author(s):  
MW Long ◽  
N Williams ◽  
S Ebbe
Keyword(s):  
Cell Cycle ◽  
Cell Types ◽  
Equilibrium Density ◽  
Early Maturation ◽  
Hydroxyurea Treatment ◽  
Cell Groups ◽  
Stimulatory Factor ◽  
Cell Cycle Status

Abstract The heterogeneity among immature megakaryocytes has been examined by physical properties, cell cycle status, and responsiveness to thrombopoietic stimulatory factor. Three types of immature megakaryocytes exist that can be recognized by acetylcholinesterase staining, nuclear shape, high nucleus/cytoplasm ratio, and small size (8--18 mu) with respect to mature megakaryocytes (greater than 18 mu). These three acetylcholinesterase-containing cell types are distinguished by their nuclear configuration: a round, indented, and lobed nucleus. The lobed cell type was found to overlap with and enhance detection of megakaryoblasts (stage I megakaryocytes). These cells had a sedimentation velocity range of 3.5--19.0 mm hr-1 and a density range of 1.072--1.095 g cm-3. Separation of these three classes of immature megakaryocytes was achieved by equilibrium density centrifugation with modal buoyant densities of 1.079 g cm-3 (round), 1.084 g cm-3 (indented), and 1.089 g cm-3 (lobed). In the presence of thrombopoietic stimulatory factor, the round nucleated cells, but not the indented or lobed nuclei morphology, were observed to develop into large mature megakaryocytes in 60-hr semisolid cell cultures. Development of two cell groups, or colonies of megakaryocytes, was not observed during this in vitro incubation period. In vivo treatment with hydroxyurea indicated that 57.5% +/- 19% of the round nucleus form were actively synthesizing DNA. No reduction in the numbers of indented or lobed nucleus forms were observed following hydroxyurea treatment. The data in this report strongly support the concept that these three types of immature megakaryocytes reflect the early maturation stages occurring in megakaryocyte differentiation.

AGGLUTININ RESPONSE TO SHEEP ERYTHROCYTES IN MICE FOLLOWING INTRAPERITONEAL INJECTION OF ALLOGENEIC SPLEEN CELLS

1963 ◽  
Vol 41 (1) ◽  
pp. 573-578
Author(s):  
Gordon O. Bain
Keyword(s):  
Spleen Cell ◽  
Intraperitoneal Injection ◽  
Depressant Effect ◽  
Spleen Cells ◽  
Sheep Erythrocytes ◽  
C3h Mice

C3H mice were injected with C57L spleen cells and 24 hours later with sheep erythrocytes. Recipients of spleen cells from C57L donors previously injected with C3H tissue developed lower antisheep hemagglutinin titers than control mice. Neither donor serum nor saline extracts of lyophilized donor spleen cells had significant cytotoxicity demonstrable in vitro. However, both heat-killed spleen cells and lyophilized spleen cells injected in vivo had a depressant effect on the anti-sheep hemagglutinin titer. The depressant effect is attributed to isoimmunization of the spleen cell donors since injection of spleen cells from donors not previously exposed to C3H antigens did not result in a lowered antisheep hemagglutinin titer.

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