RESUMEN

PURPOSE: The world's older population is growing rapidly and the need to find measures to combat age-associated decline of physical, mental, and cognitive functions and improve their health-related quality of life (HRQOL) is escalating. Biobran/MGN-3, an arabinoxylan rice bran, has been previously reported to improve the quality of life in cancer patients. The objective of the current study was to examine the effect of a low dose of Biobran/MGN-3 supplementation on the HRQOL in a healthy older adult population. METHODS: Sixty apparently healthy subjects, 40 males and 20 females, over 56 years old were recruited and blindly randomized into two group receiving either placebo or Biobran/MGN-3 (250 mg/day for 3 months). Participants did not take any vitamins or medications during the study and their health was closely monitored. HRQOL was assessed at the initiation and termination of the study using the previously validated Arabic version of SF-12v2 questionnaire. RESULTS: For all measured HRQOL domains, there was no statistically significant difference in baseline scores between the two groups. Compared to baseline values and placebo-treated subjects, Biobran/MGN-3 supplementation significantly enhanced the levels of physical and mental component summary scores as well as role-physical, bodily pain, vitality, and social functioning subdomain scores. CONCLUSION: These results show that Biobran/MGN-3 is a promising psychoneuroimmune modulatory agent that could improve the HRQOL in healthy old adults.

Asunto(s)

Calidad de Vida , Xilanos , Anciano , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oryza , Xilanos/uso terapéutico

RESUMEN

Arabinoxylan rice bran (MGN-3/Biobran) has been shown to be a potent biological response modifier (BRM) that activates different arms of the immune system, including dendritic cells (DCs), which prime CD4+ helper T-cell responses. The present study explores the ability of MGN-3-activated DCs to prime CD8+ T cells and examines the mechanisms underlying its effect. Human monocyte-derived DCs were treated with MGN-3 (20 and 40 μg/ml). Results indicate that treatment with MGN-3 caused DCs to prime higher granzyme B-expressing CD8+ T cells. Tumor lysate-pulsed MGN-3 DC also increased tumor cell killing compared to DC-stimulated CD8+ T cells. This was associated with: i) increased expression of DEC-205 in MGN-3-activated DCs in a dose-dependent manner; and ii) MGN-3 induced significant production of Type III interferon, IL29, but not Type I IFNs α and β. These results suggest that MGN-3 is a potent natural adjuvant that efficiently activates DCs and may therefore be useful for mounting an efficient immune response against infections and cancer.

Asunto(s)

Antígenos CD/fisiología , Linfocitos T CD8-positivos/efectos de los fármacos , Células Dendríticas/inmunología , Lectinas Tipo C/fisiología , Receptores de Superficie Celular/fisiología , Xilanos/farmacología , Linfocitos T CD8-positivos/inmunología , Células Cultivadas , Humanos , Interferones/metabolismo , Antígenos de Histocompatibilidad Menor , Regulación hacia Arriba

RESUMEN

The present study was carried out to investigate the synergistic apoptotic potential of arabinoxylan rice bran (MGN-3/Biobran) and curcumin (turmeric) on human multiple myeloma (MM) cell line U266 , in vitro. U266 cells were cultured with MGN-3 (50 or 100µg/ml) and curcumin (2.5-10µM) for 3 days. The effects of MGN-3 and curcumin on the growth and survival of the U266 cells were determined by trypan blue, MTT assay, flow cytometry analysis of cancer cell cycle, and apoptosis. Expression of proapoptotic Bax, and antiapoptotic Bcl2 was determined by Western blot analysis. Treatment with MGN-3 alone or curcumin alone caused a dose-dependent inhibition in the proliferation of U266 cells. However, a synergistic effect was noticed post-treatment with both agents that maximized at 100µg/ml MGN-3 plus 10µM curcumin. This synergy was characterized by an 87% decrease in cell number and a 2.6 fold increase in the percentage of apoptotic U266 cells. Cell cycle analysis showed a 53% decrease in the percentage of cells in the G0-G1 phase treated with MGN-3 and curcumin (from 36% to 17%). Analysis of the expression of the pro and antiapoptotic molecules Bax and Bcl-2 revealed synergistic effects of these agents, as the expression of Bcl-2 was decreased and Bax was increased. This resulted in a cellular microenvironment favorable for apoptosis. We conclude that MGN-3 and curcumin synergize in the induction of U266 cell apoptosis. This data may establish the foundation for in vivo studies that could have therapeutic implications.

Asunto(s)

Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Curcumina/farmacología , Mieloma Múltiple/tratamiento farmacológico , Xilanos/farmacología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Humanos , Mieloma Múltiple/patología

RESUMEN

Arabinoxylan rice bran (MGN-3/Biobran) is a potent biological response modifier (BRM) that activates natural killer (NK) cells, T cells and monocytes. Currently, little is known regarding the effects of MGN-3 on dendritic cells (DCs), the cell type that bridges innate and adaptive immunity. Therefore, we examined the stimulatory effects of MGN-3 on DCs. Human monocyte-derived DCs were treated with MGN-3 at different concentrations (5-20 microg/ml) for 24 hours in vitro. Activation of DCs was determined by assessing the expression of co-stimulatory and maturation markers (CD40, CD80, CD83, CD86 and HLA-DR) by flow cytometry, and production of cytokines by ELISA. DC function was determined by assessing their ability to activate naïve T cells. Activation of T cells was assessed by measuring cell proliferation and cytokine production. MGN-3 treatment, in a dose-dependent manner, resulted in: 1) up-regulation of the surface expression of CD83 and CD86, on DCs; 2) an increase in the production of pro-inflammatory and immuno-regulatory cytokines (IL-1beta, IL-6, IL-10, TNF-alpha, IL-12p40 and low levels of IL-12p70 and IL-2) by DCs; and 3) MGN-3 stimulated DC induced CD4+T cell proliferation and their production of cytokines, IFN-gamma, IL-10, IL-17. Results suggest that MGN-3 functions as a natural adjuvant for DC activation and thus may be used in DC-based vaccine strategies against infections and cancer.

Asunto(s)

Adyuvantes Inmunológicos/farmacología , Células Dendríticas/efectos de los fármacos , Xilanos/farmacología , Antígenos CD/metabolismo , Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Antígenos CD40/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Citocinas/metabolismo , Células Dendríticas/inmunología , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Antígenos HLA-DR/metabolismo , Humanos , Inmunoglobulinas/metabolismo , Mediadores de Inflamación/metabolismo , Activación de Linfocitos/efectos de los fármacos , Glicoproteínas de Membrana/metabolismo , Antígeno CD83

RESUMEN

Phagocytic cells, comprised of neutrophils and monocytes/macrophages, play a key role in the innate immune response to infection. Our earlier study demonstrated that arabinoxylan rice bran (MGN-3/Biobran) activates murine peritoneal macrophage and macrophage cell lines. In this study, we investigated whether MGN-3 can upregulate the phagocytic activity of human phagocytes in peripheral blood to phagocytize Escherichia coli (E. coli), trigger the oxidative burst and produce cytokines. Phagocytic cells were pre-labeled with dichlorofluorescin diacetate dye and were incubated with phycoerythrin-labeled E. coli in the presence or absence of MGN-3. Phagocytosis and oxidative burst were assessed by flow cytometry. Results showed that treatment with MGN-3 enhanced the phagocytosis of E. coli by neutrophils and monocytes. This was associated with an increased oxidative burst. In addition, it caused a significant induction of cytokines (TNF-alpha, IL-6, IL-8 and IL-10); the effect was detected at 1 microg/ml and increased in a dose-dependent manner (P

Asunto(s)

Fagocitos/efectos de los fármacos , Fagocitosis/efectos de los fármacos , Xilanos/farmacología , Bacterias/efectos de los fármacos , Línea Celular , Citocinas/biosíntesis , Humanos , Fagocitos/inmunología , Estallido Respiratorio/efectos de los fármacos

RESUMEN

MGN-3/Biobran, modified arabinoxylan rice bran, has been shown to be a potent biological response modifier (BRM) as manifested by stimulation of different arms of the immune system such as NK, T and B cells; however, its effect on macrophages has not yet been studied. The effects of MGN-3 on macrophage function was examined in vitro using 3 models: human macrophage cell line U937, murine macrophage cell line RAW264.7, and murine peritoneal macrophages (P-M phi). Treatment with MGN-3 resulted in an increase in the percentages of attachment and phagocytosis of yeast by macrophages. The effect depends on the type of macrophage and the dose of MGN-3 applied. Macrophages also demonstrated enhancement in their spreading ability, post treatment with MGN-3. Results also showed that MGN-3, in a dose dependent manner (1, 10,100 microg/ml), significantly induced high levels of production of cytokines: TNF-alpha; and IL-6. In addition, MGN-3 significantly increased nitric oxide (NO) production. This data demonstrates that MGN-3 is a potent inducer of phagocytic function by macrophage, and suggests that MGN-3 is a useful agent for fighting microbial infection.

Asunto(s)

Macrófagos/fisiología , Fagocitosis/efectos de los fármacos , Xilanos/farmacología , Animales , Apoptosis/efectos de los fármacos , Línea Celular , Humanos , Interleucina-6/biosíntesis , Activación de Macrófagos/efectos de los fármacos , Ratones , Ratones Endogámicos C3H , Óxido Nítrico/metabolismo , Saccharomyces cerevisiae/inmunología , Estimulación Química , Factor de Necrosis Tumoral alfa/biosíntesis

RESUMEN

Recently, we presented evidence for the role of MGN-3, an enzymatically modified arabinoxylan extracted from rice bran, in potent activation of human natural killer (NK) cell function in vivo and in vitro. In the current study, we examined the mechanism by which MGN-3 elevated NK cytotoxic activity. We did this by testing the action of MGN-3 on the levels of both tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) secretions and MGN-3 function on the expression of key cell surface receptors. Peripheral blood lymphocytes were treated with MGN-3 at concentrations of 0.1 mg/ml and 1 mg/ml, and supernatants were subjected to enzyme-linked immunosorbent assay. Results showed that MGN-3 is a potent TNF-alpha inducer. The effect was dose-dependent. MGN-3 concentration at 0.1 and 1 mg/ml increased TNF-alpha production by 22.8- and 47. 1-fold, respectively. MGN-3 also increased production of IFN-gamma but at lower levels as compared to TNF-alpha With respect to key cell surface receptors, MGN-3 increases the expression of CD69, an early activation antigen at 16 hours after treatment. Furthermore, the interleukin-2 receptor CD25 and the adhesion molecule ICAM-1 (CD54) were upregulated after treatment with MGN-3. Treating highly purified NK cells with MGN-3 also resulted in increased levels of TNF-alpha and IFN-gamma secretion in conjunction with augmentation of NK cell cytotoxic function. Furthermore, addition of MGN-3 to interleukin-2-activated NK cells resulted in a synergistic induction of TNF-alpha and IFN-gamma secretion. Overall, our data suggest that MGN-3, a novel biological response modifier, can be used as a safe alternative or as an adjuvant to the existing immunotherapeutic modalities.

Asunto(s)

Factores Inmunológicos/farmacología , Interferón gamma/biosíntesis , Células Asesinas Naturales/efectos de los fármacos , Factor de Necrosis Tumoral alfa/biosíntesis , Xilanos/farmacología , Adolescente , Adulto , Antígenos CD/biosíntesis , Antígenos de Diferenciación de Linfocitos T/biosíntesis , Células Cultivadas , Citotoxicidad Inmunológica , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Molécula 1 de Adhesión Intercelular/biosíntesis , Interleucina-2/farmacología , Interleucina-2/fisiología , Células Asesinas Naturales/metabolismo , Lectinas Tipo C , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Masculino , Probabilidad , Receptores de Interleucina-2/biosíntesis , Coloración y Etiquetado , Regulación hacia Arriba

RESUMEN

MGN-3 an arabinoxylane from rice bran that has been enzymatically modified with extract from Hyphomycetes mycelia, was tested for anti-HIV activity in vitro. MGN-3 activity against HIV-1 (SF strain) was examined in primary cultures of peripheral blood mononuclear cells. MGN-3 inhibited HIV-1 replication by: (1) inhibition of HIV-1 p24 antigen production in a dose dependent manner--MGN-3 concentrations of 12.5, 25, 50, and 100 micrograms/ml showed 18.3, 42.8, 59, and 75% reduction in p24 antigen, respectively; and (2) inhibition of syncytia formation maximized (75%) at concentrations of 100 micrograms/ml. Further studies showed that ingestion of MGN-3 at concentration of 15 mg/kg/day resulted in a significant increase in T and B cell mitogen response at 2 months after treatment: 146% for PHA, 140% for Con A, and 136.6% for PWM mitogen. We conclude that MGN-3 possesses potent anti-HIV activity and in the absence of any notable side effects, MGN-3 shows promise as an agent for treating patients with AIDS.

Asunto(s)

Fármacos Anti-VIH/farmacología , VIH-1/efectos de los fármacos , Polisacáridos/farmacología , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/farmacología , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/química , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Secuencia de Carbohidratos , Fusión Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Proteína p24 del Núcleo del VIH/biosíntesis , VIH-1/fisiología , Humanos , Técnicas In Vitro , Leucocitos Mononucleares , Activación de Linfocitos/efectos de los fármacos , Datos de Secuencia Molecular , Oryza , Polisacáridos/administración & dosificación , Polisacáridos/química , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Replicación Viral/efectos de los fármacos

RESUMEN

The present study examines the effect of methylcholanthrene (MCA), a a carcinogenic polycyclic hydrocarbon, on the carbohydrate receptor determinants (RD) on natural killer (NK) cell surface using the bead-coupled lectin assay. Murine NK cells exhibited different degrees of preferential binding to the specific lectins tested. Of the ten lectins tested, five exhibited a positive binding affinity while the remaining five exhibited no or insignificant binding. NK cells bind to beads derivatized with mannose specific lectins: Concanavalin A (Con A), Lens culinaris, and Pisum sativum. NK cells also bind to other lectin beads such as Triticum vulgaris (GalNac) and Vicia villosa (D-GlcNAc). All these lectin beads exhibited greater than 90% adhesion. The underivatized control beads exhibited no NK binding. The NK cells that were exposed to MCA for 2 h demonstrated a significant decrease in lectin bead-cell coupling in a dose dependent manner. MCA (10 micrograms/mL) caused a 17.8%, 40% and 4.7% decrease in binding affinity when introduced to the mannose specific lectins; Con A, L. culinaris and P. sativum beads, respectively. The binding of T. vulgaris and V. villosa to NK cells was inhibited (23.4% and 28%) by MCA treatment. An increase in the dose to 20 micrograms/mL resulted in a greater inhibition in binding affinity towards lectin beads. Con A, 35.3%, L. culinaris, 62.6%, P. sativum, 30.9%, T. vulgaris, 44.2% and V. villosa, 46.2%. The effect of MCA activation and cytotoxic response. Hydrolysis of PI metabolites (PIP and PIP2) cause generation of secondary messenger: inositol-1,4,5-triphosphate and diacylglycerol, both of which elicit an immune response through their products (Ca2+ and PKC) respectively. Identification of the relationship between receptor level, induction of second messenger and cytotoxic activity may resolve the molecular basis of suppression of NK cytotoxicity by MCA and other PAH compounds.

Asunto(s)

Carcinógenos/toxicidad , Células Asesinas Naturales/efectos de los fármacos , Metilcolantreno/toxicidad , Animales , Carbohidratos/química , Dimetilsulfóxido , Células Asesinas Naturales/metabolismo , Lectinas/química , Masculino , Ratones , Fosfatidilinositol 4,5-Difosfato/biosíntesis , Fosfatos de Fosfatidilinositol/biosíntesis

RESUMEN

This review article summarizes molecular markers that can signal enhanced risk of cancer and provide clinicians with these clues in order to attempt the use of natural and synthetic compounds to intervene in the early precancerous stages of carcinogenesis before invasive disease begins. With an aim such as this in mind, we have begun to apply molecular techniques based on many research articles to look for biomarkers capable of signaling a greater risk of cancer. It is possible to attain relatively quick answers by monitoring selected signs and damage in the body which provide the environment for abnormal cell growth and differentiation. These molecular techniques aim to uncover critical precancerous events taking place inside the body and identify measurable biologic flags signaling their occurrence. For years now, scientists have understood that the onset of cancer is a gradual, step-wise process that may unfold over the course of decades, rather than a single, fixed event that can be dated in a pathologist's report. Carcinogenesis usually encompasses the prolonged accumulation of injuries at several different biological levels and includes both genetic and biochemical changes in cells. At each of these levels there is an opportunity for intervention-a chance to prevent, slow or even halt the gradual march of healthy cells toward malignancy. It is estimated that 75% of cancers are induced by chemicals; thus, if exposure to chemicals is avoided, cancer can be prevented. Also, depending on the individual's genetic background, the ability to metabolize chemicals is different among the population. This means that, "you and I can be exposed to exactly the same amount of a chemical," yet our response will differ because we metabolize carcinogens differently due to different rates of deoxyribonucleic acid (DNA) repair, apoptosis, and mitosis or different levels of Phase I and Phase II detoxification enzymes. This, along with a more or less efficient immune system, may promote tumor formation or destroy a cancer cell at its earliest stage of development. Therefore, measurement of the biologic markers such as DNA and protein adducts, DNA damage, programmed cell death, DNA repair system, mitosis, gene activation, levels of antioxidants and efficient immune function described in this chapter and summarized in Figures 2 and 10, are biological clues indicating that the body has been assaulted by toxic (or cancer-causing) agents. This early identification of biomarkers for special vulnerability to the effects of chemicals and detection of selected signs of precancerous damage in the body may culminate preventive measures and the saving of lives.

Asunto(s)

Neoplasias/química , Apoptosis/fisiología , Biomarcadores de Tumor/análisis , Ciclo Celular/fisiología , Aductos de ADN/análisis , Daño del ADN , Humanos , Proteínas de Neoplasias/análisis , Neoplasias/genética , Neoplasias/prevención & control , Factores de Riesgo

RESUMEN

OBJECTIVES: A prominent feature of chronic fatigue syndrome (CFS) is a disordered immune system. Recent evidence indicates that induction of apoptosis might be mediated in a dysregulated immune system by the upregulation of growth inhibitory cytokines. Therefore, the purpose of this study was to evaluate the apoptotic cell population, interferon-alpha (IFN-alpha) and the IFN-induced protein kinase RNA (PKR) gene transcripts in peripheral blood lymphocytes (PBL) of CFS individuals, as compared to healthy controls. SUBJECTS AND METHODS: PBL were isolated from CFS (n = 29) and healthy control individuals (n = 15) and subjected to quantitative analysis of apoptotic cell population and cell cycle progression by flow cytometry. Quantitative competitive polymerase chain reaction (Q/C PCR) and Western blot analysis were used to assess the levels of PKR mRNA and protein in control and CFS individuals. In addition, circulating IFN-alpha was measured by ELISA assay. RESULTS: Increased apoptotic cell population was observed in CFS individuals, as compared to healthy controls (26.6 +/- 12.9% and 9.9 +/- 4.2%, respectively). The increased apoptotic subpopulation in CFS individuals was accompanied by an abnormal cell arrest in the S phase and the G2/M boundary of the cell cycle as compared to the control group (8.6 +/- 1.2 to 22.8 +/- 2.4 and 3.6 +/- 0.82 to 24.3 +/- 3.4, respectively). In addition, CFS individuals exhibited enhanced PKR mRNA and protein levels (mean basal level 3538 +/- 1050 and 2.7 +/- 0.26, respectively) as compared to healthy controls (mean basal level 562 +/- 162 and 0.89 +/- 0.18, respectively). In 50% of the CFS samples (n = 29) treated with 2-aminopurine (2-AP) (a potent inhibitor of PKR) the apoptotic population was reduced by more then 50%. CONCLUSIONS: PKR-mediated apoptosis in CFS individuals may contribute to the pathogenesis and the fatigue symptomatology associated with CFS.

Asunto(s)

Apoptosis , Síndrome de Fatiga Crónica/sangre , Interferón-alfa/farmacología , Linfocitos/enzimología , Proteínas Quinasas/genética , ARN/genética , 2-Aminopurina/farmacología , Adolescente , Adulto , Anciano , Antimetabolitos/farmacología , Apoptosis/efectos de los fármacos , Western Blotting , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Linfocitos/efectos de los fármacos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa/métodos , Proteínas Quinasas/efectos de los fármacos , ARN/efectos de los fármacos , Transcripción Genética/efectos de los fármacos

RESUMEN

Immunological abnormalities including lymphocyte subset, lymphocyte immune functional assays, chemical antibodies, and different markers for autoimmune response were examined in individuals exposed to a variety of chemicals in computer manufacturing plants. A comparison of 289 individuals exposed to chemicals to 120 controls revealed that exposed individuals had a significantly higher percentage with either increased or decreased T helper/T suppressor ratios. In addition, the individuals with abnormal T4/T8 ratios demonstrated significant elevation in chemical-hapten antibodies. Therefore, 87 exposed subjects with abnormal T4/T8 ratios were selected for further evaluation by lymphocyte phenotypic expression and T cell, B cell, NK activity, and autoimmune markers, and were compared to 60 controls. The comparison of exposed individuals with controls indicated elevation of T cell (CD3), B cell (CD19), and activated T cell (CD10, CD15, CD26, CD38), suppressed T cell and B cell function decreased or increased NK cell cytotoxic activity. Autoimmunity due to chemical exposure was evidenced by elevation of TA1 phenotype frequencies and presence of rheumatoid factor, immune complexes, ANA, and anti myelin basic protein antibodies. We conclude that chemical exposure may induce immune abnormalities including immune suppression and autoimmunity.

Asunto(s)

Linfocitos B/efectos de los fármacos , Computadores , Cianatos/efectos adversos , Formaldehído/efectos adversos , Células Asesinas Naturales/efectos de los fármacos , Exposición Profesional/efectos adversos , Anhídridos Ftálicos/efectos adversos , Linfocitos T/efectos de los fármacos , Adulto , Antígenos de Diferenciación , Linfocitos B/inmunología , Humanos , Persona de Mediana Edad , Linfocitos T/inmunología , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunología

RESUMEN

Previous studies indicated that natural killer (NK) activity in mice declined with age. In this report, we investigated the basis for the decreased activity of NK cells in older mice. Our results demonstrated that phorbol myristate acetate (PMA)--an activator of protein kinase C (PKC)--corrects the impaired NK function of older animals. The per cent increase of NK activity post treatment with PMA is 226-261% at effector:target (E:T) ratio = 100:1 compared with control untreated cells. The effect of PMA was shown to be dose dependent. A maximum increase in NK activity was achieved at approximately 10-15 nM PMA. Treatment with PMA does not result in increased binding of NK cells to YAC-1 targets as demonstrated by single-cell assay. In addition, treatment of young NK cells with 1-(5-isoquinolinesulphonyl)-2-methylpiperazine dihydrochloride (H-7), a very potent PKC inhibitor, significantly suppressed NK activity (65% of control). Therefore, we conclude that the age-related decline in murine NK activity may reside in the early signalling events leading to triggering of PKC.

Asunto(s)

Células Asesinas Naturales/efectos de los fármacos , Ratones Endogámicos C3H/inmunología , Acetato de Tetradecanoilforbol/farmacología , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina , Envejecimiento/inmunología , Animales , Adhesión Celular/inmunología , Citotoxicidad Inmunológica/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Técnicas In Vitro , Isoquinolinas/farmacología , Células Asesinas Naturales/inmunología , Ratones , Piperazinas/farmacología , Inhibidores de Proteínas Quinasas , Proteínas Quinasas/farmacología

RESUMEN

The effects of tributyltin chloride (TBTCl) and inorganic tin (IT) on murine natural killer (NK) cell activity were tested in vivo and in vitro. In vivo studies demonstrated that mice fed with TBT (10 and 100 ppm) daily for 1 week exhibited suppression in NK activity 38-46% at effector:target (E:T) ratio = 50:1 compared to control mice. On the other hand, animals treated with inorganic tin showed no change in activity of NK cells. In vitro studies showed leukocytes, preincubated with TBTCl (0.01-0.1 ppm) at room temperature for 1 h and then washed three times, demonstrated significant suppression in NK activity (41 and 85%) at concentrations 0.01 and 0.05 ppm, respectively. Increasing the dose to 0.1 ppm, resulted in complete inhibition of the activity of NK cells. In contrast, IT had no effect on NK activity in vitro at the same concentrations of TBTCl. The effect of TBTCl appears to be due to interference with the binding capacity of effector cells, a necessary prerequisite for target cell lysis. In conclusion, TBTCl proved to be a very potent inhibitor of NK activity; this inhibition may predispose animals to malignancy, which is a characteristic feature reported recently for some TBT compounds.

Asunto(s)

Células Asesinas Naturales/efectos de los fármacos , Compuestos de Trialquiltina/toxicidad , Animales , Dieta , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Células Asesinas Naturales/inmunología , Leucocitos/efectos de los fármacos , Leucocitos/inmunología , Masculino , Ratones , Ratones Endogámicos C3H , Estaño/toxicidad , Compuestos de Trialquiltina/administración & dosificación

RESUMEN

In the present study, we analysed the phenomenon of leukophagocytosis by tumour cells with respect to the age of the animal. Splenic leukocytes from C3H mice at different ages were depleted of macrophages and used as targets against tumour effector cells. Tumour cell lines P388D1, a macrophage lymphoma of mouse origin and LAZ-559, a B cell lymphoma of human origin, were cultured with leukocytes at 37 degrees C and 5 per cent CO2 for 4 h and the percentage of phagocytic tumour cells were examined in cytospin preparations. The results demonstrated that the phagocytic activity of P388D1 cells was 10, 6, 3 and 28 per cent against 1, 2, 6, and 35 week-old mice respectively; while LAZ-559 showed lower activity; 5, 3, 1.5 and 17 per cent against leukocytes of corresponding ages. Susceptibility of old leukocytes to phagocytosis could be detected as early as 30 min after culture with tumour cells, and increased with increasing incubation period. At 4 h, phagocytosis by tumour cells resulted in 38 and 29 per cent reduction in the leukocyte number postculture with P388D1 and LAZ-559 cells respectively. We postulate that an age-related decline in immune function is associated with increased level of phagocytic tumour cells, and that the loss of leukocytes may have adverse effects on the immune system.

Asunto(s)

Envejecimiento/inmunología , Linfocitos/inmunología , Fagocitosis , Células Tumorales Cultivadas/inmunología , Animales , Recuento de Leucocitos , Linfocitos/patología , Masculino , Ratones , Ratones Endogámicos C3H

Asunto(s)

Anuros/inmunología , Células Asesinas Naturales/inmunología , Animales , Bufonidae/inmunología , Adhesión Celular , Citotoxicidad Inmunológica , Variación Genética , Rana catesbeiana/inmunología , Rana pipiens/inmunología

RESUMEN

A new monoclonal antibody (MAB), IA61gG2a, has been derived from Balb/c mice after immunization with T-cell chronic lymphocytic leukemia (T-CLL). This monoclonal antibody, 1A6 was tested on normal human peripheral blood cells, leukemia patients' cells and leukemia-lymphoma cell lines. The results demonstrated that this antibody reacts with normal human T and B cells, but not with erythrocytes, granulocytes or platelets. Further examinations showed 10/11 leukemic patient cell types were positive with 1A6. In contrast, many leukemia-lymphoma cell lines were negative (14/17), i.e. T and B leukemia lymphoma cell lines, non-T and non-B leukemia cell lines as examined by complement mediated cytotoxicity test and immunofluorescence test. Other prominent characteristics of 1A6 MAB have been demonstrated, which include inhibition of myeloid colony formation (CFU-C) and suppression of human natural killer cell cytotoxicity (NKCC). These results suggest that 1A6 is a common marker for normal T, B, NK cells and leukemic patients cells having T and B cell origin, but 1A6 antigen is not expressed on many leukemia lymphoma cell lines. Therefore, it could be useful for studying malignant transformation of lymphoid cells.

Asunto(s)

Anticuerpos Monoclonales/inmunología , Antígenos de Neoplasias/inmunología , Antígenos de Superficie/inmunología , Unión Competitiva , Células Asesinas Naturales/inmunología , Leucemia/inmunología , Linfocitos T/inmunología , Animales , Anticuerpos Monoclonales/fisiología , Reacciones Antígeno-Anticuerpo , Línea Celular , Ensayo de Unidades Formadoras de Colonias , Pruebas Inmunológicas de Citotoxicidad , Humanos , Ratones , Distribución Tisular

RESUMEN

Our earlier observations revealed that social stress causes drastic effects on different physiological mechanisms and degenerative changes in leucocytes. In this preliminary work, we analyzed the effect of social aggressiveness on functional activities of leucocytes emphasizing (NCC) activity in Tilapia. At 10 hr post stress induction, fish could be differentiated into three categories: 1) dominants; 2) subordinates; and 3) indeterminants. Results of NCC as indicated by 4 hr. 51Cr-release assay, demonstrated a significant suppression in cytotoxic reactivity in the subordinates and indeterminants compared to dominants. This suppression appears to be due to a decrease in the binding capacity of effector cells to YAC-1 target cells as indicated by the decreased number of conjugate forming cells. This binding process is a key event in activating the fish equivalent of NK cells in mammals. Decreased NCC-activity in stressed fish suggests that aberrations in cell mediated immunity result from social aggressiveness.

Asunto(s)

Agresión/fisiología , Peces/inmunología , Animales , Citotoxicidad Inmunológica , Femenino , Tolerancia Inmunológica , Inmunidad Celular , Inmunidad Innata , Leucocitos/inmunología , Masculino

RESUMEN

Eighty-nine random Pap smears of the uterine cervix were examined to evaluate the phagocytic abnormal cells (PACs) of atypical, dysplastic and neoplastic tissues against infiltrated blood cells. The results revealed that none of the PACs have been identified in atypical (II) and mild dysplastic cells (IIIa). Low levels (1.2%) of PACs were initially demonstrated in patients with moderate dysplasia (IIIb) that increased 1.7-fold in subsequent severe dysplasia (IIIc) and further increased 2.8-fold in invasive carcinomas of the cervix (V). In addition, the data showed age-related responsiveness toward the development of PACs, where 82% of old patients have developed phagocytic activity in moderate dysplastic cells compared with 27% of young patients. However, the difference became less significant at the subsequent classes of the disease. These data further demonstrated that PACs are class-dependent and it may explain one mechanism by which precancerous cells escape immunosurveillance.

Asunto(s)

Linfocitos/inmunología , Fagocitosis , Neoplasias del Cuello Uterino/inmunología , Adolescente , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Persona de Mediana Edad , Displasia del Cuello del Útero/clasificación , Displasia del Cuello del Útero/inmunología , Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/clasificación , Neoplasias del Cuello Uterino/patología

Asunto(s)

Ciprinodontiformes/efectos de la radiación , Estrógenos/farmacología , Oryzias/efectos de la radiación , Traumatismos Experimentales por Radiación/prevención & control , Animales , Femenino , Rayos gamma , Masculino