scholarly journals Differences in iron requirements by concanavalin A-treated and anti-CD3-treated murine splenic lymphocytes

2002 ◽  
Vol 88 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Solo R. Kuvibidila ◽  
Maria Velez ◽  
Lolie Yu ◽  
Raj P. Warrier ◽  
B. Surendra Baliga
Keyword(s):  
Dna Synthesis ◽  
T Cell Activation ◽  
Concanavalin A ◽  
Lymphocyte Proliferation ◽  
Reductase Activity ◽  
Interleukin 2 ◽  
Calf Serum ◽  
Ammonium Citrate ◽  
Ferric Ammonium Citrate ◽  
Splenic Lymphocytes

Fe availability is critical for optimal lymphocyte proliferation; however, the minimum required levels are unknown. Such information is valuable when assessingin vitroimmune responses in Fe-deficient subjects, because serum (Fe) added to the culture medium may replete lymphocytes. To address this issue, splenic lymphocytes obtained from seventeen 3-month-old C57BL/6 mice were incubated without and with 1 mg/l concanavalin A or 50 μg/l anti-CD3 antibody in media that contained between 0·113 and 9·74 μmol Fe/l. Fe was provided by either fetal calf serum (FCS, 0–100 ml/l), newborn calf serum (NBCS, 0–100 ml/l), or NBCS (10 ml/l) plus ferric ammonium citrate. As expected, the rate of DNA synthesis increased with Fe levels (P<0·01). Maximum DNA synthesis was obtained with 2·26 μmol Fe/l (50 ml FCS/l) for concanavalin A and 0·895 μmol/l (20 ml FCS/l) for anti-CD3-treated cells. In serum-free media (0·113 μmol Fe/l), the proliferative responses to concanavalin A were below the background, while they rose 5·5-fold in anti-CD3-treated cells (P<0·05). In apotransferrin-supplemented media (0·13 μmol Fe/l), the proliferative responses to concanavalin A and anti-CD3 antibody were 18·6 and 71 %, respectively, of that obtained with 4·66 μmol Fe/l (100 ml FCS/l). Interleukin 2 secretion also followed the same trend as lymphocyte proliferation. Since differences between both mitogens persisted after FCS was substituted with NBCS, we can rule out an effect on ribonucleotide reductase activity, or by other serum growth factors. We speculate an Fe effect at an early step of T-cell activation. Data suggest that the minimum Fe concentration required for lymphocyte proliferation varies with the mitogen.

Taxol-induced reorganization of the microtubule system in murine splenic lymphocytes inhibits response to allogeneic cells but not to concanavalin A

1988 ◽  
Vol 66 (5) ◽  
pp. 389-395 ◽  
Author(s):  
Chitra Roy ◽  
Nathalie Chaly ◽  
David L. Brown
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Concanavalin A ◽  
Proliferative Response ◽  
Interleukin 2 ◽  
Microtubule Assembly ◽  
Mixed Leukocyte Reaction ◽  
Splenic Lymphocytes ◽  
Leukocyte Culture

The exposure of mouse splenic lymphocytes to the microtubule assembly-promoting drug taxol (10 μM for 4 h) results in an extensive reorganization of the microtubule system to form one to a few large bundles of microtubules, which extend from the centrosome. Lymphocytes pretreated with taxol for 4 h, or cultured in the continued presence of taxol, respond normally to the mitogen concanavalin A up to, and including, the stage of DNA replication. In contrast, the induction of DNA synthesis during the alloactivation of lymphocytes is inhibited when taxol is present in the mixed leukocyte culture. If the stimulators are pretreated with this drug, the mixed leukocyte reaction occurs normally, but pretreatment of the responders inhibits the proliferative response markedly. Microscopic observations of nuclear morphologies in these populations and autoradiography indicate that taxol inhibition occurs early in alloactivation, prior to DNA replication. The responding ability of taxol-treated lymphocytes is not restored to control levels by the addition of interleukin 2, leading to the suggestion that interleukin 2 receptors do not emerge or function normally in these cells. We conclude that the capacity to respond to allogeneic cells, but not to a mitogen, is dependent on the presence of the normal submembranous organization of the microtubule system.

Influence of exercise on the immune function of rats of various ages

1988 ◽  
Vol 64 (5) ◽  
pp. 1997-2001 ◽  
Author(s):  
M. A. Pahlavani ◽  
T. H. Cheung ◽  
J. A. Chesky ◽  
A. Richardson
Keyword(s):  
Immune Function ◽  
Concanavalin A ◽  
Lymphocyte Proliferation ◽  
Interleukin 2 ◽  
Training Period ◽  
Sedentary Control ◽  
Age Related ◽  
Old Rats ◽  
Spleen Lymphocytes ◽  
F344 Rats

The purpose of this study was to determine whether exercise could prevent the age-related decline in mitogenesis, which has been well documented in rats, mice, and humans. At 1, 6, 12, and 18 mo of age, male Fischer F344 rats were subjected daily to swimming exercise for 6 mo. At the end of the 6-mo training period, spleen lymphocytes were isolated from the exercised rats and from age-matched sedentary controls. The induction of lymphocyte proliferation was measured with the mitogens concanavalin A (ConA) and lipopolysaccharide (LPS). In addition, the ability of the lymphocytes to produce interleukin 2 (IL 2) in response to ConA induction was measured. ConA- and LPS-induced proliferation decreased 41–63% between 7 and 25 mo of age in both exercised and sedentary control rats. ConA-induced IL 2 production decreased 42 and 62% between 7 and 25 mo of age for exercised and sedentary control rats, respectively. Although the age-related decline in mitogen-induced proliferation and IL 2 production was smaller in exercised rats, this was due to a lower level of mitogenesis and IL 2 production in lymphocytes from young exercised rats. Exercise resulted in a significant decrease (23–32%) in mitogen-induced lymphocyte proliferation and IL-2 production in 7-mo-old exercised rats compared with 7-mo-old sedentary rats. However, in the 18- and 24-mo-old rats, mitogen-induced lymphocyte proliferation and IL 2 production was not significantly different between exercised and sedentary control rats.

Participation of Interleukins in Synergistic Effect of Bu-WSA on Concanavalin A-Induced DNA Synthesis in Mouse Splenic Lymphocytes

2006 ◽  
Vol 24 (3) ◽  
pp. 297-305
Author(s):  
T. NITTA ◽  
H. KONNO-EJIRI ◽  
K. NEMOTO ◽  
S. OKUMURA ◽  
A OZAWA ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Dna Synthesis ◽  
Concanavalin A ◽  
Splenic Lymphocytes

scholarly journals Retinoids are important cofactors in T cell activation.

1992 ◽  
Vol 176 (1) ◽  
pp. 109-117 ◽  
Author(s):  
A Garbe ◽  
J Buck ◽  
U Hämmerling
Keyword(s):  
T Cells ◽  
Retinoic Acid ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Calf Serum ◽  
Cell Receptor ◽  
Signal Pathway ◽  
Necrosis Factor Alpha

Murine thymic T cells depleted of antigen-presenting cells proliferate poorly in response to crosslinking anti-CD3 monoclonal antibodies or concanavalin A when cultured in conventional fetal calf serum-containing serum. However, in a serum-free medium formulated to contain, in addition to basic ingredients, insulin, transferrin, albumin, linoleic acid (ITLB), and retinol, proliferation is vigorous. The presence of retinol is critical, because when omitted, cells do not become activated. The subsets of T cells proliferating with the assistance of retinol cofactor are both CD4+ and CD8+ thymic T cells, and CD4+ peripheral T cells. Mature CD8+ T cells of lymph nodes can also be activated in ITLB medium plus retinol, provided that interleukin 2 (IL-2) is added. Retinol needs to be present at the time when T cell receptor triggering is initiated, suggesting that early activation events (G0 to G1 transition) are dependent on retinol. It is currently less clear whether or not subsequent events associated with G1 to S phase transition also require the presence of retinol. 14-hydroxy-retroretinol (14HRR) is a metabolic product of retinol in lymphocytes, and this retinoid effectively supports T cell activation in conjunction with a mitogen in lieu of retinol. Thus, while retinol and its intracellular product, 14HRR, are unable to activate T cells on their own, they are important cofactors. The requirement for retinol in CD3-mediated T cell activation cannot be satisfied by retinoic acid or ILs-1, 2, 4, and 6, and tumor necrosis factor-alpha whereas interferon gamma can substitute for retinol. Our experiments are compatible with the idea that retinol, in the course of cellular activation, is converted to 14HRR, which is needed as intracellular messenger. If substantiated by molecular studies now underway, our data should lead to the description of a new signal pathway distinct from the retinoic acid signal pathway observed in nonlymphoid cells, but perhaps functioning by a similar mechanism, i.e., ligand-assisted transcriptional regulation.

Iron acquisition by oral hemolytic spirochetes: isolation of a hemin-binding protein and identification of iron reductase activity

1996 ◽  
Vol 42 (10) ◽  
pp. 1072-1079 ◽  
Author(s):  
D. Scott ◽  
R. Siboo ◽  
E. C. S. Chan
Keyword(s):  
Binding Protein ◽  
Reductase Activity ◽  
Iron Acquisition ◽  
Ammonium Citrate ◽  
Ferric Ammonium Citrate ◽  
Affinity Column ◽  
Treponema Denticola ◽  
Apparent Homogeneity ◽  
Iron Reductase

Oral anaerobic spirochetes (OAS) have been implicated in the etiology of periodontal disease. To adapt to the environment of the subgingiva, OAS must be able to acquire iron from limited sources. OAS have previously been shown not to produce siderophores but are β-hemolytic and can bind hemin via a proteinaceous 47-kDa outer membrane sheath (OMS) receptor. Present studies show that [3H]hemin is not transported into the cytoplasm, that hemin and ferric ammonium citrate, as the sole iron sources, can support the growth of OAS and that protoporphyrin IX and Congo red are inhibitory, thereby implying an important in vivo role for hemin as an iron source. Treponema denticola ATCC 35405 produces an iron reductase. The iron reductase can reduce the central ferric iron moiety of hemin. The 47-kDa OMS hemin-binding protein has been purified to apparent homogeneity by methanol–chloroform extraction of cellular lipoproteins and the use of a hemin–agarose bead affinity column. A model of iron acquisition by OAS is presented.Key words: Treponema denticola, hemin-binding protein, iron limitation, iron reductase.

IGF-I potentiates interleukin-2 production in human peripheral T cells

1996 ◽  
Vol 149 (2) ◽  
pp. 351-356 ◽  
Author(s):  
R Kooijman ◽  
G T Rijkers ◽  
B J M Zegers
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dna Synthesis ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Cell Types ◽  
Peripheral T Cells ◽  
Proliferation And Differentiation ◽  
Igf I

Abstract IGF-I stimulates the proliferation and differentiation of many cell types. In the case of T cells, IGF-I has been described to potentiate mitogen-induced DNA synthesis. We have addressed the working mechanism of IGF-I on T cell proliferation by measuring the effects of IGF-I on various stages of T cell activation. We found that IGF-I augmented the phytohaemagglutinin- and anti-CD3-induced interleukin-2 (IL2) production of human peripheral T cells before they enter the S phase of the cell cycle. Furthermore, the addition of IGF-I did not influence DNA synthesis of IL2-dependent growing T cells. Journal of Endocrinology (1996) 149, 351–356

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