scholarly journals THE EFFECTS OF ANTIGENS AND OF PHYTOHEMAGGLUTININ ON RABBIT SPLEEN CELL SUSPENSIONS

1966 ◽  
Vol 124 (4) ◽  
pp. 621-634 ◽  
Author(s):  
G. Harris ◽  
R. J. Littleton
Keyword(s):  
Dna Synthesis ◽  
Spleen Cell ◽  
Cell Suspensions ◽  
Red Cells ◽  
Specific Response ◽  
Spleen Cells ◽  
Sheep Red Cells ◽  
Stimulation Of

Phytohemagglutinin (PHA) stimulated the rate of DNA synthesis in rabbit spleen cell suspensions. Unlike antigens, previous immunization to PHA was not necessary and the specific response could not be transferred by macrophages, although lymphocytes primed by incubation in PHA were able to stimulate other spleen cells not directly exposed to PHA. When rabbits were stimulated by in vivo immunization with antigens, spleen cells proliferating in response to antigen were stimulated to divide by in vitro contact with PHA. Using the technique of specific hemolytic plaque formation by individual cells synthesizing γM-antibody to sheep red cells (plaque-forming cells), no evidence was obtained that stimulation of cell division by PHA resulted in specific antibody formation, although the presence of antigen resulted both in stimulation of cell proliferation and the production of plaque-forming cells. The presence of both sheep red cells and PHA in the medium of the same cell suspensions did not enhance the production of plaque-forming cells although there was a summative effect on DNA synthesis.

scholarly journals CD4pos, NK1.1pos T cells promptly produce interleukin 4 in response to in vivo challenge with anti-CD3.

1994 ◽  
Vol 179 (4) ◽  
pp. 1285-1295 ◽  
Author(s):  
T Yoshimoto ◽  
W E Paul
Keyword(s):  
T Cells ◽  
Spleen Cell ◽  
Great Majority ◽  
Cell Suspensions ◽  
Interleukin 4 ◽  
Cellular Interactions ◽  
Spleen Cells ◽  
Ifn Gamma

Injection of anti-CD3 antibodies causes prompt expression of interleukin (IL)-4, IL-2, and interferon gamma (IFN-gamma) mRNA among spleen cells. The optimal dose of anti-CD3 for such induction was 1.33 microgram/animal; lymphokine mRNA was first observed at 30 min, peaked at 90 min, and was undetectable (for IL-4) or had declined markedly by 4 h. Cells harvested from spleens of mice injected with anti-CD3 90 min earlier secreted IL-4, IL-2, and IFN-gamma without further stimulation. By contrast, in vitro stimulation with anti-CD3 of spleen cell suspensions or splenic fragments from noninjected donors failed to cause prompt production of IL-4 and, even after 24 h of stimulation, the amount of IL-4 produced in such cells was substantially less than that secreted within 1 h by spleen cell suspensions or splenic fragments from mice injected with anti-CD3 90 min earlier. Production of IL-4 by spleen cells from anti-CD3-injected mice was not inhibited by pretreatment with anti-IL-4 antibody or with IFN-gamma or tumor growth factor beta nor enhanced by treatment with IL-4. By contrast, CTLA-4 immunoglobulin (Ig) treatment clearly diminished IL-4 production in response to in vivo anti-CD3, indicating that cellular interactions involving CD28 (or related molecules) were important in stimulation. Cell sorting analysis indicated that the cells that produced IL-4 in response to in vivo injection of anti-CD3 were highly enriched in CD4pos cells with the phenotype leukocyte cell adhesion molecule-1 (LECAM-1)dull, CD44bright, CD45RBdull, NK1.1pos. Indeed, the small population of CD4pos, NK1.1pos cells had the great majority of the IL-4-producing activity of this population. Injection with Staphylococcal enterotoxin B also caused prompt induction of IL-4 mRNA; the cells that were principally responsible for production also had the phenotype of CD4pos, NK1.1pos. These results suggest that possibility that this rare population of T cells may be capable of secreting IL-4 at the outset of immune responses and thus may act to regulate the pattern of priming of naive T cells, by providing a source of IL-4 to favor the development of T cell helper 2-like IL-4-producing cells.

Thrombopoietin-Induced Stimulation of Megakaryocyte- Enriched Bone Marrow Cultures

1979 ◽  
Author(s):  
K. L. Kellar ◽  
B. L. Evatt ◽  
C. R. McGrath ◽  
R. B. Ramsey
Keyword(s):  
Bone Marrow ◽  
Dna Synthesis ◽  
Bone Marrow Cells ◽  
Rabbit Plasma ◽  
Bone Marrow Cultures ◽  
Plasma Fractions ◽  
Marrow Cultures ◽  
Stimulation Of

Liquid cultures of bone marrow cells enriched for megakaryocytes were assayed for incorporation of 3H-thymidine (3H-TdR) into acid-precipitable cell digests to determine the effect of thrombopoietin on DNA synthesis. As previously described, thrombopoietin was prepared by ammonium sulfate fractionation of pooled plasma obtained from thrombocytopenic rabbits. A control fraction was prepared from normal rabbit plasma. The thrombopoietic activity of these fractions was determined in vivo with normal rabbits as assay animals and the rate of incorporation of 75Se-selenomethionine into newly formed platelets as an index of thrombopoietic activity of the infused material. Guinea pig megakaryocytes were purified using bovine serum albumin gradients. Bone marrow cultures containing 1.5-3.0x104 cells and 31%-71% megakaryocytes were incubated 18 h in modified Dulbecco’s MEM containing 10% of the concentrated plasma fractions from either thrombocytopenic or normal rabbits. In other control cultures, 0.9% NaCl was substituted for the plasma fractions. 3H-TdR incorporation was measured after cells were incubated for 3 h with 1 μCi/ml. The protein fraction containing thrombopoietin-stimulating activity caused a 25%-31% increase in 3H-TdR incorporation over that in cultures which were incubated with the similar fraction from normal plasma and a 29% increase over the activity in control cultures to which 0.9% NaCl had been added. These data suggest that thrombopoietin stimulates DNA synthesis in megakaryocytes and that this tecnique may be useful in assaying thrombopoietin in vitro.

scholarly journals Primary generation of cytolytic T lymphocytes in the absence of DNA synthesis.

1979 ◽  
Vol 150 (1) ◽  
pp. 196-201 ◽  
Author(s):  
H R MacDonald ◽  
R K Less
Keyword(s):  
T Lymphocytes ◽  
Dna Synthesis ◽  
Cytolytic Activity ◽  
Target Cells ◽  
Cytolytic T Lymphocytes ◽  
Spleen Cells ◽  
Con A ◽  
A Cell ◽  
Stimulation Of

The requirement for DNA synthesis during the primary differentiation of cytolytic T lymphocytes (CTL) had been investigated. CTL were induced polyclonally in vitro by stimulation of normal C57BL/6 spleen cells with concanavalin A (Con A)and their cytolytic activity was tested against 51Cr-labeled target cells in the presence of Bacto Phytohemagglutinin M. With this system, CTL activity could first be detected 48 h after exposure of spleen cells to Con A. Addition of cytosine arabinoside at concentrations sufficient to reduce DNA synthesis by 95-98% in Con A-stimulated cultures did not significantly inhibit the generation of cytolytic activity on a cell-to-cell basis. These results demonstrate that derepression of the genetic information required for the expression of CTL function can occur in the absence of detectable DNA synthesis.

scholarly journals GENETIC CONTROL OF IMMUNE RESPONSES IN VITRO

1974 ◽  
Vol 140 (3) ◽  
pp. 648-659 ◽  
Author(s):  
Judith A. Kapp ◽  
Carl W. Pierce ◽  
Stuart Schlossman ◽  
Baruj Benacerraf
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Immune Responses ◽  
Cell Function ◽  
Suppressor Cells ◽  
Specific Response ◽  
Spleen Cells ◽  
X Irradiation

In recent studies we have found that GAT not only fails to elicit a GAT-specific response in nonresponder mice but also specifically decreases the ability of nonresponder mice to develop a GAT-specific PFC response to a subsequent challenge with GAT bound to the immunogenic carrier, MBSA. Studies presented in this paper demonstrate that B cells from nonresponder, DBA/1 mice rendered unresponsive by GAT in vivo can respond in vitro to GAT-MBSA if exogenous, carrier-primed T cells are added to the cultures. The unresponsiveness was shown to be the result of impaired carrier-specific helper T-cell function in the spleen cells of GAT-primed mice. Spleen cells from GAT-primed mice specifically suppressed the GAT-specific PFC response of spleen cells from normal DBA/1 mice incubated with GAT-MBSA. This suppression was prevented by pretreatment of GAT-primed spleen cells with anti-θ serum plus C or X irradiation. Identification of the suppressor cells as T cells was confirmed by the demonstration that suppressor cells were confined to the fraction of the column-purified lymphocytes which contained θ-positive cells and a few non-Ig-bearing cells. The significance of these data to our understanding of Ir-gene regulation of the immune response is discussed.

scholarly journals Immunologic stimulation of early murine hematopoiesis and its abrogation by cyclosporin A

Blood ◽  
1982 ◽  
Vol 59 (4) ◽  
pp. 851-856 ◽  
Author(s):  
SA Burstein ◽  
SK Erb ◽  
JW Adamson ◽  
LA Harker
Keyword(s):  
Immune Response ◽  
Cyclosporin A ◽  
Progenitor Cells ◽  
Pokeweed Mitogen ◽  
Normal Rabbit Serum ◽  
Lymphocyte Function ◽  
Spleen Cells ◽  
Stimulation Of

Abstract Mice injected chronically with antiplatelet serum develop an increase in the number of megakaryocytic progenitor cells compared to animals given normal rabbit serum. To examine the specificity of this response, progenitor cells giving rise to megakaryocyte, granulocyte-macrophage, erythroid, and mixed-cell colonies were assayed after injection of various heterosera or saline. All four colony types increased in the serum-treated groups. Since the in vitro proliferation of hematopoietic progenitor cells is promoted by supernatants of mitogen-stimulated spleen cells, we hypothesized that the immune response following antiserum administration resulted in the in vivo activation of T lymphocytes which produced or led to the production of colony stimulating activities. To test this hypothesis, cyclosporin A, a preferential inhibitor of T lymphocyte function, was given to mice concurrently with antiserum and also added to spleen cell cultures in the presence of pokeweed mitogen. Cyclosporin A abrogated the antiserum- related increases in progenitor cell numbers in vivo and the production of colony stimulating activity in vitro. The results suggest that the immune response related to antiserum administration results in the in vivo production of hematopoietic colony stimulating activities that may be identical to those produced in vitro by mitogen-stimulation of spleen cells.

scholarly journals RADIOAUTOGRAPHIC STUDIES OF PLAQUE-FORMING CELLS

1968 ◽  
Vol 128 (2) ◽  
pp. 235-257 ◽  
Author(s):  
Aurelia M. C. Koros ◽  
John M. Mazur ◽  
Margaret J. Mowery
Keyword(s):  
Cell Proliferation ◽  
Dna Synthesis ◽  
Tritiated Thymidine ◽  
Red Cells ◽  
G1 Phase ◽  
Spleen Cells ◽  
Antigen Dose ◽  
Sheep Red Cells ◽  
Large Populations ◽  
S Period

A method has been described for obtaining radioautographs of plaque-forming cells. The method permits radioautographic analyses of small numbers of plaque-forming cells amidst large populations of non-plaque-forming cells. Spleen cells that were pulse-labeled with tritiated thymidine could be categorized readily as labeled or not labeled. Using this method it was found that (a) at least 55% of plaque-forming cells which appear 3 days after a maximal stimulus of 4 x 108 sheep red cells are still capable of DNA synthesis, and must have arisen by cell proliferation; (b) the rate of proliferation of plaque-forming cells is proportional to the log of the dose of antigen; (c) the S period of plaque-forming cells is at least 2 hr, appears to be constant, and is not influenced by antigen dose. The results suggest that antigen stimulates proliferation of plaque-forming cells by hastening their transit through the G1 phase of the generative cycle.

scholarly journals Immunologic stimulation of early murine hematopoiesis and its abrogation by cyclosporin A

Blood ◽  
1982 ◽  
Vol 59 (4) ◽  
pp. 851-856 ◽  
Author(s):  
SA Burstein ◽  
SK Erb ◽  
JW Adamson ◽  
LA Harker
Keyword(s):  
Immune Response ◽  
Cyclosporin A ◽  
Progenitor Cells ◽  
Pokeweed Mitogen ◽  
Normal Rabbit Serum ◽  
Lymphocyte Function ◽  
Spleen Cells ◽  
Stimulation Of

Mice injected chronically with antiplatelet serum develop an increase in the number of megakaryocytic progenitor cells compared to animals given normal rabbit serum. To examine the specificity of this response, progenitor cells giving rise to megakaryocyte, granulocyte-macrophage, erythroid, and mixed-cell colonies were assayed after injection of various heterosera or saline. All four colony types increased in the serum-treated groups. Since the in vitro proliferation of hematopoietic progenitor cells is promoted by supernatants of mitogen-stimulated spleen cells, we hypothesized that the immune response following antiserum administration resulted in the in vivo activation of T lymphocytes which produced or led to the production of colony stimulating activities. To test this hypothesis, cyclosporin A, a preferential inhibitor of T lymphocyte function, was given to mice concurrently with antiserum and also added to spleen cell cultures in the presence of pokeweed mitogen. Cyclosporin A abrogated the antiserum- related increases in progenitor cell numbers in vivo and the production of colony stimulating activity in vitro. The results suggest that the immune response related to antiserum administration results in the in vivo production of hematopoietic colony stimulating activities that may be identical to those produced in vitro by mitogen-stimulation of spleen cells.

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.

Gentamicin-induced stimulation of DNA synthesis in rat kidney comparison between in vivo and in vitro models

1984 ◽  
Vol 23 (2) ◽  
pp. 205-213 ◽  
Author(s):  
G.A. Porter ◽  
G. Laurent ◽  
P. Maldague ◽  
P. Tulkens
Keyword(s):  
Dna Synthesis ◽  
Rat Kidney ◽  
In Vitro Models ◽  
Stimulation Of
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