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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alpha2-HF, foetal and tumorous isoferritin, the level of which is high in cancerous patients and in amniotic fluid during pregnancy, has an immunosuppressif effect on normal lymphocytic response. Its activity has been tested on blastic transformation induced by PHA, tuberculin, candidin and allgenic lymphocytes. The inhibition effect is proportional to the added quantity of alpha2-HF globulin. The antibody synthesis is depressed by alpha2-HF as demonstrated in vivo and in vitro. Iron is no responsible for the suppressif effect: the efficiency is identical with the native protein or the apo-protein. Crystallised ferritin, without sugar in its molecule on the contrary of alpha2-HF which is a glycoferroprotein, has no suppressif effect.
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PMID:[Modification of the immune response by a hepatic ferroglobulin: L alpha2-HF]. 6 97

The relationship between iron status and capacity for IL-2 production by lymphocytes was assessed in 81 children from 6 mo to 3 yr of age selected at random from a population with low socioeconomic status, undergoing free systematic examination in four children's health centers in the Paris area. Iron deficiency was defined by the existence of at least two abnormal values among the three indicators of iron status: serum ferritin level less than or equal to 12 micrograms/L, transferrin saturation less than 12%, and erythrocyte protoporphyrin concentration greater than 3 micrograms/g hemoglobin. According to this definition, 53 children were classified as iron deficient and 28 as iron sufficient. No differences were observed between the iron-deficient and iron-sufficient groups in terms of the IL-2 concentration without stimulation by PHA. IL-2 production by lymphocytes stimulated with PHA, as well as the stimulation index (ratio of IL-2 concentration following stimulation by PHA to that of IL-2 concentration without stimulation by PHA) were significantly lower in iron-deficient children. The reduction in IL-2 production by activated lymphocytes observed in our study of iron-deficient children may be responsible for impairments in immunity found by other authors, particularly in cell-mediated immunity.
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PMID:Interleukin 2 production in iron-deficient children. 137 84

Our previous studies showed that some antigenic and mitogenic substances, when locally injected into mice, efficiently produced new lymph follicles outside pre-existing follicles in draining lymph nodes, whereas others had virtually no effect. In the present experiments, young adult male mice were injected with several antigens and mitogens in the rear footpad, and the number and development sites of newly produced lymph follicles in the draining popliteal nodes were studied using serial sections of the nodes obtained between 5 and 21 days after injection. In the unstimulated state, each popliteal node contained a limited number of lymph follicles which mostly lay in a portion of the peripheral cortex overlaying the deep cortex (this portion is referred to as the PCOU), whereas a portion of the peripheral cortex extending beyond the deep cortex (referred to as the PCBU) was underdeveloped with only occasional follicles. Mice treated with soluble PHA or fluid tetanus toxoid developed germinal centers in association with existing follicles but failed to produce new follicles. The PCBU of the draining nodes remained underdeveloped, and the number and distribution pattern of lymph follicles within a draining node were comparable to those in the control node. Animals treated with LPS (50 micrograms), Con A, alum-precipitated PHA or alum-precipitated tetanus toxoid produced significantly large numbers of new follicles outside pre-existing follicles in the draining nodes, the new follicles produced in the PCBU being generally more numerous than those in the PCOU. In these draining nodes, the peripheral cortex, comprising a number of follicles, was found to overlie the deep cortex and extend beyond the deep cortex towards the hilar region. In animals given a less effective stimulant, such as ferritin or a smaller dose of LPS (10 micrograms), the draining nodes produced a relatively small number of new follicles, most of which were formed in the PCBU. The present results indicate that in the mouse popliteal node, the PCBU is morphologically underdeveloped under normal conditions, but develops lymph follicles in response to exogenous stimuli more readily than the PCOU, and that substances efficient in inducing follicle formation can be regarded as capable of stimulating the development of the peripheral cortex.
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PMID:Sites of lymph follicle formation in the draining popliteal lymph nodes of mice locally injected with antigenic and mitogenic substances. 213 2

The localization of complex carbohydrates in the Golgi apparatus, secretory granules and plasmalemma of mouse parotid acinar cells was studied using the fracture-labelling method. The hexose residues of glycoconjugates were identified using ferritin conjugated with Wheat Germ Agglutinin (WGA-), Ricinnus Communis Agglutinin II (RCA-II-), Phaseolus Vulgaris Agglutinin (PHA-) and Limulus Polyphemus Agglutinin (LPA-). We found that the fracture-labelling method allows not only the labelling of membrane faces but also analysis of the compartment's content that is exposed during the fracturing of the tissue. Our results revealed differences in the hexose residues located in the Golgi apparatus, secretory granules and the apical and lateral plasmalemma. Numerous binding sites for WGA-, PHA- and RCA-II-ferritin were demonstrable in the Golgi apparatus. In secretory granules, the WGA- and RCA-II-ferritin binding sites were most numerous, while LPA-ferritin binding sites were very rare. The density of the binding sites for PHA-ferritin showed considerable variation in secretory granules. The apical plasmalemma exhibited a high density of binding sites for all of the lectins used. In the lateral plasmalemma, LPA-ferritin was not bound, and there were fewer binding sites for WGA-, RCA-II- and PHA-ferritin.
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PMID:Lectin-binding pattern in parotid acinar cells. The fracture-labelling method and post-embedding staining. 243 Sep 21

IL2-induced lymphocytes (IIL) obtained from normal subjects were examined as to a possibility for induction of tumor-specific killer cells. Moreover, effects of serum on their cytotoxic activity were observed. The IIL which were pre-sensitized with mitomycin C-treated MKN-28 (IILM), showed a markedly increased cytotoxic activity against MKN-28. The IIL which were either pre-cultured with PHA or not, showed augmentation of cytotoxic activity against various human cancer cell lines, although their cytotoxic activity against MKN-28 was lower than that of IILM. The cytotoxic activity of IILM was suppressed by addition to the medium of non-specific immunosuppressive factors (IAP, ferritin, alpha-fetoprotein) or of various sera obtained from gastric cancer patients, in whom histological diagnosis was tub1, por or sig, but the suppression to the IILM activity was significantly milder than that to the activity of peripheral lymphocytes. The degree of suppression by tub1 serum was significantly higher than that by the serum from por or sig. When tub1 serum was added to the medium during pre-sensitization, the cytotoxic activity of IILM against MKN-28 was reduced significantly. However, addition of por or sig serum showed no significant reduction in cytotoxic activity of IILM.
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PMID:[Cytotoxicity of interleukin 2-induced lymphocytes and effects of serum immunosuppressive factors]. 300 73

Peripheral blood mononuclear cells (PBM) pulsed with lectin (PHA or Con A for 0.25-3 hr) show a low expression of interleukin-2 and transferrin receptors (IL-2Rs, TfRs) and a mild decline of intracellular ferritin level, compared to control cultures grown in continuous presence of mitogen. Interestingly, lectin-pulsed PBM do not release detectable amounts of IL-2 in the medium. Furthermore, expression of TfRs in these lymphocytes is not inhibited by addition of excess anti-IL-2 neutralizing monoclonal antibody, but is significantly inhibited by treatment with iron salts. These observations suggest that mitogen triggers an IL-2-independent expression of TfRs, at least in part via a decrease of intracellular iron level. Addition of either recombinant IL-2 (rIL-2) or an iron chelator (picolinic acid) to lectin-pulsed PBM induces both a marked enhancement of TfR synthesis and a sharp decline of intracellular ferritin level, which are comparable to the corresponding pattern observed in control cultures. Conversely, addition of iron salts fully inhibits the increase of TfR expression induced by rIL-2. These observations strongly suggest that the enhanced TfR synthesis elicited by rIL-2 is mediated by depletion of a regulatory intracellular iron pool. In line with these studies, greater than 99% purified T lymphocytes stimulated by lectin show a low expression of TfRs, which is markedly enhanced by addition of exogenous rIL-2. Altogether, we postulate that: (i) in resting T lymphocytes the gene encoding TfR is apparently in a 'closed' configuration; (ii) even in the absence of IL-2 activity, a mitogen pulse is sufficient to initiate the expression of TfRs, at least in part via a decline of intracellular iron level; and (iii) TfR synthesis is then largely amplified by IL-2, again via a decrease of the size of a regulatory intracellular iron pool.
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PMID:Mechanisms underlying T-lymphocyte activation: mitogen initiates and IL-2 amplifies the expression of transferrin receptors via intracellular iron level. 313 96

To evaluate the modulatory effects of trace metals on lymphocyte growth and maturation, thymidine uptake (TU), protein, ATP, Fe, Cu, Zn, ferritin, CD3, CD4, CD8 antigens, surface transferrin receptors (TFR) and interleukin 2 receptors (IL2R) were assessed in normal and T cell leukemia human lymphocytes, cultured in media with varying Fe, Cu and Zn concentrations [Me]. In normal lymphocytes in media with optimal [Me], all values increased significantly after PHA stimulation, except for intracellular metal concentration and CD3+, CD4+, CD8+ cells which were unchanged. In media with low or high [Me], all parameters except for CD8+ cells were decreased. In unstimulated ALL lymphocytes grown in media with optimal [Me], TU, protein, ATP, CD4+, Fe, Cu and ferritin were higher and Zn and CD8+ lower than in unstimulated normal cells: they did not change after PHA stimulation, except in media with low [Me], in which they approached the values of stimulated normal lymphocytes. TFR and IL2R for ALL cells were high in all media: IL2R but not TFR increased after PHA stimulation. No relationship between IL2R and TFR was demonstrable in any media. We conclude that the response of normal lymphocytes to stimuli is sensitive to variation in trace metals, whereas this response, absent in ALL lymphocytes, reappears only in media with low [Me] and is independent from TFR.
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PMID:Trace metals, surface receptors and growth of human normal and leukemic lymphocytes. 326 16

Cancer grows in interaction with the host, that is, a host-tumor relationship exists. Investigations of host factors in patients receiving cancer chemotherapy are important, as they reveal the conditions in which a tumor response can develop. Furthermore, reliable host factors, if present, will be useful for quantitative evaluation of the effects of treatment. We have investigated the following three categories of host factors in relation to the effects of cancer chemotherapy and/or immunotherapy. CBC, and blood chemistries (44 parameters). Tumor markers; sialic acid, RNase, lysozyme, ferritin, IAP (immunosuppressive acidic protein), elastase I, AFP, CEA, POA, CA 19-9, CA 125, etc. Immunological parameters; lymphocyte, active T cell, T cell, B cell, IgG Fc receptor-positive T cell, lymphocyte blastogenesis stimulated by PHA, or concanavalin-A, ADCC activity, interferon production in vitro induced by poly I: C, or PHA, PPD skin test, immune complex, immunoglobulin G, A, and M, OKT series 3, 4, 8, 11, 4/8 ratio, antihuman HLA-DR, Leu 11, NK cell activity, etc. From our clinical observations, there were no significant differences in the pretreatment levels of these parameters between responders and non-responders. In responders, there was a tendency for the host factors to show greater degrees of improvement following treatment than in non-responders, but none proved to be reasonably reliable parameters for evaluating therapeutic effects. On the other hand, from our clinical observations on the advanced gastric cancer cases, life span showed a close correlation with tumor regression induced by cancer chemotherapy. Because of these facts, it is only natural that the clinical effects of chemotherapy are currently determined by definite tumor regression.
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PMID:[Host factors in cancer chemotherapy]. 372 33

We have examined the binding and internalization of cationized ferritin in T-lymphocytes of human peripheral blood, as a model for resting cells. After 30 min of incubation only 8% of endocytotic vesicles contain cationized ferritin. T-cells internalize the equivalent of their entire surface area in approximately 54 h, a longer time than is required by non-resting cells such as PHA-stimulated human lymphocytes. These tracer experiments suggest that the endocytosis of cationized ferritin by T-lymphocytes follows a lysosome pathway similar to that described for other cell types.
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PMID:Endocytosis of cationized ferritin in human peripheral blood by resting T-lymphocytes. 387 94

We have previously demonstrated that lentil phytohemagglutinin (lentil-PHA) binds to human platelet membranes without causing either aggregation or the release reaction. When platelets are treated with thrombin, there is an increase in lentil-PHA binding suggesting the appearance of new receptor sites on the cell surface. We prepared a lentil-PHA-ferritin conjugate using affinity chromatography which was used to saturate cell surface receptor sites. Studies using this conjugate suggest that thrombin causes a complex change in the platelet surface involving a decrease in the number of lentil-PHA receptor sites on the external platelet surface with a marked increase in sites within the center of the canalicular system. These increased sites may result from fusion of granule membranes with the canalicular membranes during the secretion process. There is no obvious relationship between lentil-PHA receptor sites and intramembranous particles.
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PMID:The effects of thrombin on phytohemagglutinin receptor sites in human platelets. 420 95


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