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PubMed1991

[Effect of zinc on immune function in normal mice].

Swiss mice were used for studying the effects of zinc on the immune function and on the structure of thymus. The experimental results showed that: 1) When mice were administered with a dose of zinc 0.2mg/d of mouse for 15 d, the number of mature T lymphocyte in peripheral blood increased significantly, the transformation of lymphocytes and DTH response were both markedly enhanced; phagocytosis of peritoneal macrophage was suppressed, but the production of IgM and the weight of thymus were not affected. 2) The shape of lymphocyte nucleus of the thymus cortex became irregular by administration of zinc. So, a certain immunity promotive dose of zinc may impose a latent injury to the lymphocyte of thymus.

Animals↗
PubMed2004

Effects of dehydroepiandrosterone on ovarian cystogenesis and immune function.

The purpose of the present report was to study the possible relationship between ovarian functionality and the immune response during cystogenesis induced by androgenization with dehydroepiandrosterone (DHEA). Daily injection of DHEA (6 mg/kg body weight) for 20 consecutive days induced ovarian cysts in BALB/c mice. As markers of ovarian function, serum estradiol (E) and progesterone (P) and the ovarian inmunomodulator prostaglandin E (PGE) were analyzed. In order to know how the integrity of the tissue was altered after induction of cystogenesis, the oxidative status was also evaluated. Serum E and P levels, and ovarian PGE concentration, were increased in animals with cysts compared with healthy controls. The oxidant status (quantified by malondialdehyde (MDA) formed after the breakdown of the cellular membrane by free radical mechanisms) was augmented, meanwhile the antioxidant (evaluated by the glutathione (GSH) content) diminished during the induction of cystogenesis. Both immunohistochemical and flow cytometry assays demonstrated that DHEA treatment increased the number of T lymphocytes infiltrating ovarian tissue. Therefore, while ovarian controls showed equivalent expression of CD4+ and CD8+ T cell subsets, injection of DHEA yielded a selective ovarian T cell infiltration as demonstrated by enhanced CD8+ and diminished CD4+ T lymphocyte expression. These results show that the development of cysts involves changes in ovarian function and an imbalance in the oxidant-antioxidant equilibrium. We observed also both an increased and selective T lymphocyte infiltration.

Adjuvants, Immunologic↗
PubMedDate not supplied

Membrane alterations in health and disease with particular reference to immune function and cancer.

Ever since the early microscopists and experimental biologists distinguished the fundamental differences between the animal and plant cells, investigations on the structure and function of the cell membrane have become a fascinating field of biomedical research. The membranes of all types of cells provide the biological border, and maintain the integrity of the cell by protecting it from toxic insult rendered by chemicals, biochemicals, toxins etc. The toxic damage of the cell membrane results in an alteration of the transport mechanism or transmits a message for altered DNA, RNA and protein synthesis, vis-a-vis altered cell division which ultimately leads to death of the cell. In fact, the ligand receptor binding, with particular reference to toxicants of different kinds, may alter the normal physiological function of the cell. If the damaged cell is involved in immune function, the host becomes more susceptible to infection. Prolonged immunosuppression may predispose the host to develop cancer, although cancer cells themselves originate as a result of genetic damage caused by environmental toxicants, endocytosed after binding with membrane receptors, finally reaching the genomic material to cause carcinogenic alteration. The phenomena of membrane binding, transmission of message, processing of message and eventual alteration of biomolecular structure consequently resulting in a disorder or disease process are described in the present communication.

Animals↗
PubMed2002

Expression profile of the channel catfish spleen: analysis of genes involved in immune functions.

Both qualitative and quantitative patterns of tissue-specific gene expression can be determined using gene profiling. Expressed sequence tag (EST) analysis is an efficient approach not only for gene discovery and examining gene expression, but also for development of molecular resources useful for functional genomics. As part of an ongoing transcriptome analysis of channel catfish (Ictalurus punctatus), EST analysis was conducted for gene annotations and profiling using a complementary DNA library developed from messenger RNA of the spleen. A total of 1204 spleen cDNA clones were analyzed. Of the 1204 clones, 665 clones (55.2%) were identified as orthologs of known genes from other organisms by BLAST searches and 539 clones (44.8%) as unknown gene clones. In total 147 novel genes were identified, and annotations were made to 118 of them. In addition, 389 novel EST clusters were identified. Expression profile was analyzed in relation to metabolic functional groups. A total of 28 known genes were involved in immune functions, of which 10 were identified for the first time in channel catfish. Microsatellite-containing clones were also identified that may be potentially useful for genome mapping. This work contributed to the Catfish Gene Index, and toward a Unigene set useful for functional genomics research concerning spleen gene functions in relation to disease defenses.

Journal Article↗
PubMed2003

Immune function in turkey breeder hens during the short day prelighting period and renewal of photosensitivity for egg production.

Photorefractoriness (PR) in the turkey breeder hen is characterized by a lack of responsiveness to photoperiods that previously induced or maintained egg production. The consequence of PR is spontaneous regression of ovarian function and cessation of lay. Photosensitivity (PS) may be regained by giving at least 8 wk of short photoperiod (8L:16D) (light restriction). Following the transition from PR to PS, the birds may be photostimulated with long photoperiods, which allows for the recrudescence of ovarian function and normal egg production. Although the return of reproductive viability is the parameter for determining the successful recycle of ovarian function, there are no known reports of the physiological costs of this transition on immune function in the turkey breeder hen. We conducted an experiment to determine the immune responsiveness at various stages of recycle in the turkey breeder hen. Fifty photorefractory birds were selected and distributed equally among five treatment groups (time points). All birds were given an 8-wk period of light restriction (8L:16D) followed by a 12-wk period of photostimulation (16L:8D). The cellular (cutaneous basophil hypersensitivity CBH) and humoral (antibody titer) immune responses were determined in each treatment group (sequential time points): prelight restriction, 2-wk light restriction, 7-wk light restriction, 2-wk photostimulation, and 12-wk photostimulation. After 2-wk light restriction, there was a reduction in the cellular (64.1%) and humoral (59.5%) immune responses from that of the PR hens at the start. After 7-wk light restriction, the humoral responses increased (33.5%) as compared to the 2-wk light restriction time point Upon photostimulation, both the cellular (23.3%) and humoral (52.4%) immune responses were reduced at 2 wk of photostimulation as compared to the prior 7-wk light restriction time point. Finally, there was a rise in cellular (45.7%) and humoral (72.3%) immune responses after 12 wk of photostimulation as compared to the prior 2-wk photostimulation time point. We concluded that recycling of PR turkey hens was associated with altered cellular and humoral immune responses characterized by initial decline then recovery in both the light restriction and the postphotostimulation periods.

Animals↗
PubMed2006

Effects of pulsed magnetic stimulation on tumor development and immune functions in mice.

We investigated the effects of pulsed magnetic stimulation on tumor development processes and immune functions in mice. A circular coil (inner diameter = 15 mm, outer diameter = 75 mm) was used in the experiments. Stimulus conditions were pulse width = 238 micros, peak magnetic field = 0.25 T (at the center of the coil), frequency = 25 pulses/s, 1,000 pulses/sample/day and magnetically induced eddy currents in mice = 0.79-1.54 A/m(2). In an animal study, B16-BL6 melanoma model mice were exposed to the pulsed magnetic stimulation for 16 days from the day of injection of cancer cells. A tumor growth study revealed a significant tumor weight decrease in the stimulated group (54% of the sham group). In a cellular study, B16-BL6 cells were also exposed to the magnetic field (1,000 pulses/sample, and eddy currents at the bottom of the dish = 2.36-2.90 A/m(2)); however, the magnetically induced eddy currents had no effect on cell viabilities. Cytokine production in mouse spleens was measured to analyze the immunomodulatory effect after the pulsed magnetic stimulation. tumor necrosis factor (TNF-alpha) production in mouse spleens was significantly activated after the exposure of the stimulus condition described above. These results showed the first evidence of the anti-tumor effect and immunomodulatory effects brought about by the application of repetitive magnetic stimulation and also suggested the possible relationship between anti-tumor effects and the increase of TNF-alpha levels caused by pulsed magnetic stimulation.

Animals↗
PubMed2004

Daily low-dose subcutaneous interleukin-2 added to single- or dual-nucleoside therapy in HIV infection does not protect against CD4+ T-cell decline or improve other indices of immune function: results of a randomized controlled clinical trial (ACTG 248).

CONTEXT: Approaches to preserve or enhance immune function in HIV-1 infection are needed. OBJECTIVES: To examine the ability of daily low-dose interleukin-2 (IL-2) in combination with antiretroviral therapy to preserve circulating CD4+ T-cell counts, the clinical safety and tolerability of this treatment, and safety with respect to changes in plasma HIV-1 RNA levels. DESIGN: Twenty-four-week, phase 2, multicenter, randomized, open-label trial conducted at 12 AIDS Clinical Trials Units between September 1995 and May 1997. PARTICIPANTS: A total of 115 HIV-infected persons with screening CD4+ T-cell counts between 300 and 700 cells/mm who were on stable single- or dual-nucleoside therapy for at least 2 months, 11% of whom were also on a protease inhibitor at study entry. INTERVENTIONS: Patients were randomly assigned to receive IL-2 at a dose of 1 million IU subcutaneously once daily plus continued anti-retroviral therapy (ART + IL-2, n = 57) vs. continued ART alone (ART alone, n = 58). IL-2 dose reductions were made for objective or subjective toxicities. All subjects randomly assigned to the IL-2 arm who interrupted ART were also required to discontinue IL-2 for the same period. MAIN OUTCOME MEASURES: The primary endpoint was a decrease in CD4 T-cell count from baseline; the safety analysis was based on change in plasma HIV RNA by bDNA; and clinical safety and tolerability were analyzed by standard clinical criteria. RESULTS: Of the patients with a baseline CD4 T-cell count recorded, 15 (27%) of 55 patients randomly assigned to ART alone had a drop of > or =25% in their CD4 T-cell count and 23 (41%) of 56 patients randomly assigned to ART + IL-2 had a drop of > or =25% in their CD4 T-cell count at some time over the 24 weeks of the study. This difference was not statistically significant. There was a statistically significant greater variance in CD4 T-cell counts in the IL-2-treated group. More patients in the IL-2 group had at least a 25% increase in CD4 T-cell counts over baseline (34 vs. 13%, P = 0.007). A comparison of grade 3 or worse toxicity showed no differences between the arms, but IL-2 was associated with significantly more grade 2 or worse general body symptoms, primarily discomfort and fatigue. There was no significant difference between the groups with regard to changes in plasma HIV RNA, lymphocyte proliferation, natural killer cell activity, skin test responses to recall antigens, or antibody responses to immunization. Plasma markers of immune activation all increased significantly in IL-2 recipients. CONCLUSIONS: In patients with baseline CD4 T-cell counts > or =300 cells/mm primarily treated with single- or dual-nucleoside ART, subcutaneously administered IL-2 at a dose of 1 million IU daily for up to 24 weeks had low toxicity but showed no consistent benefit in preventing decline in CD4 T-cell counts and minimal evidence of immunologic improvement vs. continued ART alone.

AIDS Vaccines↗
PubMed1990

Effect of psychological intervention in the form of relaxation and guided imagery on cellular immune function in normal healthy subjects. An overview.

The present study measured the effects of relaxation and guided imagery on cellular immune function. During a period of 10 days 10 healthy subjects were given one 1-hour relaxation procedure and one combined relaxation and guided imagery procedure, instructing the subjects to imagine their immune system becoming very effective. Even though no major changes in the composition of the major mononuclear leukocyte subsets could be demonstrated a significant increase in natural killer function was demonstrated. These data suggest that relaxation and guided imagery might have a beneficial effect on the immune defense and could form the basis of further studies on psychological intervention and immunological status.

Adult↗
PubMed1993

Influence of beta-carotene on immune functions.

Recent reports have demonstrated that beta-carotene, a nontoxic carotenoid, is able to stimulate immune functions in humans. The purpose of this study is to understand the mechanisms of immunoenhancement by carotenoids in order to explain their anticancer effects. We have evaluated the clinical efficacy of beta-carotene, given 30 mg/day orally, for treatment of oral leukoplakia patients. Patients who responded to beta-carotene treatment showed increased plasma levels of TNF-alpha. Epithelial cells from these patients were characterized in vitro. These results may lead to a better understanding of the therapeutic use of beta-carotene in humans.

Adjuvants, Immunologic↗
PubMed2004

Effect of chronic clenbuterol administration and exercise training on immune function in horses.

Effects of longitudinal exercise training and acute intensive exercise (simulated race test) on immune function have not been reported in horses. Clenbuterol, a beta2-adrenergic agonist, is used to manage inflammatory airway disease in horses. This study investigated the interaction of 8 wk of exercise training with or without 12 wk of clenbuterol administration in horses. Twenty-three untrained standardbred mares (10 +/- 3 yr, Mean +/- SE) were used and divided into four experimental groups. Horses given clenbuterol plus exercise (CLENEX; n = 6) and clenbuterol alone (CLEN; n = 6) received 2.4 microg/kg BW of clenbuterol twice daily (in an average volume of 20 mL) on a schedule of 5 d on and 2 d off for 12 wk. The CLENEX group was also aerobically trained 3 d/wk. Mares given exercise alone (EX; n = 5) were aerobically trained for 3 d/wk, and the control group (CON; n = 6) remained sedentary. Both EX and CON horses were administered similar volumes (approximately 20 mL) of molasses twice daily. A simulated race test (SRT) resulted in an elevation in lymphocyte number postexercise (P < 0.05). There was no significant difference after acute exercise in either monocyte or granulocyte number. Acute exercise resulted in a decrease (P < 0.05) in the percentage of CD4+ and an increase (P < 0.05) in the percentage of CD8+ cells. The SRT resulted in a decreased lymphoproliferative response to pokeweed mitogen (P < 0.05). A SRT had no effect on antibody production in response to equine influenza vaccine. The EX group demonstrated greater cortisol concentrations at rest and at all other time points postexercise after completing the training regimen compared with CLENEX horses (P < 0.05). Preexercise (SRT) peripheral blood monocyte number was lower in CLENEX horses than in other treatment groups (P < 0.05). Clenbuterol and exercise training did not significantly affect post-SRT changes in leukocyte numbers. Exercise training resulted in a decrease (P < 0.05) in the percentage of CD8+ cells post-SRT compared with other groups, but the percentage of CD4+ cells was not altered by either clenbuterol or exercise conditioning. Lymphocyte proliferative response was not affected by clenbuterol or exercise treatment. Horses demonstrated responses to bouts of acute exercise as noted with other species, namely humans and rodents.

Adrenergic beta-Agonists↗
PubMed1982

Lack of immunostimulatory effect of N-acetyl muramyl-L-alanyl-D-isoglutamine on selected chicken immune functions.

Synthetic N-acetyl muramyl-L-alanyl-D-isoglutamine, syn. muramyl-dipeptide (MDP) was found to be immunostimulatory in several experimental animal species. In order to determine the influence of MDP on the chicken immune response, different doses (0.05-0.2 mg) of this compound were administered to 6-week old chickens, and cellular as well as humoral immune functions were tested. Neither the immune response against sheep red blood cells or Newcastle disease virus (strain Hitchner B 1), nor the ability to reject skin grafts, or to react in the delayed hypersensitivity (tuberculin) test, were affected significantly under the experimental conditions employed. This study reveals little evidence for parallels between the ability of the chicken immune system and the immune system of other animal species examined so far, to develop enhanced immune reactions under the influence of MDP.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed2000

[Effect of sub-acute low level exposure to lead on cellular immune function in rats].

In order to observe the influence of low level exposure to lead on cellular immune functions in rats, sixty rats were randomly divided into six groups and were received diets with different levels of lead for eight weeks. Blood lead, serum tumor necrosis factor-alpha(TNF-alpha) level and the distribution of T lymphocyte subsets were measured. The pathological and ultrastructural changes of spleen were investigated. It was shown that lead exposure resulted in a significant increase of blood lead and decrease of the number of CD4 T-cells. But no significant difference was found in CD8 T-cell among all groups. Serum TNF-alpha at the lowest exposure group was significantly increased but that in other groups was lower than the control group. Electron microscopy for splenic immune cells indicated no significant difference between the lowest lead exposure group and the control group. The mitochondria of other groups were swollen, vaculated and pyknotic, endoplasmic reticulum were swollen and degranulated, nuclear chromatin were loosen. It was suggested that sub-acute exposure to lead, even at relative low exposure, would impair cell-mediated immunity and be harmful to spleen and thymus.

Animals↗
PubMed1995

Effects of artesunate on immune function in mice.

AIM: To study the effects of artesunate (dihydroartemisinine-12-alpha-succinate, Art) on immune function in mice. METHODS: Hemolysin concentration was determined by colorimetric method. Serum IgG and C3 contents were measured by single immunodiffusion method. Percentage of lymphocyte transformation, phagocytosis percentage and phagocytic index were counted under microscope. RESULTS: Art im 75 mg kg-1 bid x 7 d decreased the humolysin-forming capacity and levels of serum IgG of mice sensitized with sheep red blood cell. The serum complement 3 level rose remarkably, when Art was given im to Plasmodium berghei-infected mice. Art enhanced the PHA-induced lymphocyte transformation rate (in vivo) in mice and increased the weight of spleen but reduced that of thymus in mice. Art elevated the DNFB-induced delayed-type hypersensitivity. Art im 75 mg kg-1 bid x 5 d reduced the percentage of phagocytosis of peritoneal macrophages and the phagocytic index. CONCLUSION: Art suppressed the humoral immune responses but enhanced the cell-mediated immunity.

Adjuvants, Immunologic↗
PubMed1999

Nutrition and immune function in human immunodeficiency virus infection.

The triad of human immunodeficiency virus (HIV) infection, nutritional status and immune function are intimately related, each factor having effects on the others. The dominant effect in this three-way relationship is the effect of HIV infection on nutritional status, an effect which, until the advent of potent anti-retroviral drugs, has been manifest primarily as wasting. Recently, more complex metabolic abnormalities have become apparent, particularly fat redistribution syndromes, hyperlipidaemia and hypercholesterolaemia. For the converse effect, the effect of nutritional state on HIV disease progression, there is good evidence that clinical outcome is poorer in individuals with compromised nutrition. However, the beneficial effects of nutritional support have been more difficult to demonstrate. For macronutrients, effective macronutrient supply improves survival in severely-malnourished individuals and may have beneficial effects in less-severely-affected individuals. Micronutrient deficiencies appear to be involved in modifying clinical HIV disease and may also be associated with enhanced mother-to-child transmission of virus, particularly in developing countries. Intervention trials in this setting are currently under way. In conclusion, the interaction of HIV infection and nutrition is of great importance not just because of the major impact that HIV infection has on nutritional state, but also because strategies to improve nutritional status, both quantitatively and qualitatively, may have a beneficial effect on the clinical and immunological course of the disease.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Brown seaweed- (Tasco) treated conserved forage enhances antioxidant status and immune function in heat-stressed wether lambs.

Twenty-seven wether lambs were utilized to evaluate select innate immunity and oxidative stress in response to diet and heat stress. Dietary treatments were: (i) control (tall fescue) hay = no Tasco (tradename for the extract of the brown seaweed, Ascophyllum nodosum, Acadian Sealants Ltd, Nova Scotia, Canada); (ii) pre-harvest Tasco-Forage-treated hay and (iii) control hay + post-harvest Tasco-EX. Tasco-Forage and Tasco-EX are two forms of the Tasco extract that are either applied to foliage or used for direct feeding, respectively. All lambs were supplemented with soyabean meal and trace mineralized salt. Heat stress was applied for 10 days with measurements obtained at days 0, 4 and 10. A heat x treatment interaction indicated hay with Tasco enhanced monocyte oxidative burst through short duration (p < 0.05) and long duration (p < 0.10) heat stress. Phagocytic activity was influenced by days of heat stress (p < 0.001) and treatment (p = 0.02) with post-harvest Tasco lambs exhibiting the greatest immune enhancement (p < 0.05). Red and white blood cell glutathione peroxidase increased by heat stress day 10 in Tasco lambs. Superoxide dismutase activity was increased and lipid hydroperoxide metabolites minimized (p < 0.01) through long duration heat stress in the pre-harvest Tasco group. Tasco treatment of tall fescue hay prior to harvest appears to provide residual effects on animal antioxidant availability in short-duration heat stress. Tasco supplementation to post-harvest fescue hay enhances immune function and protects against prolonged heat-induced oxidative stress.

Animal Feed↗
PubMed2005

[Study on the effects of two kinds of cactus polysaccharide on erythrocyte immune function of S180 mice].

OBJECTIVE: To study the effects of two kinds of cactus polysaccharide on erythrocyte immune function in S180 mice. METHOD: Classical pharmaceutical method and test kit. RESULT: The cactus polysaccharide increased the content of RBC-CaR, RFER, decreased the content of RFIR, raised the content of sialic acid. And the effect of median dose group of medical cactus polysaccharide and high dose group of edible cactus polysaccharide is very remarkable (P < 0.01) compared with model group. CONCLUSION: The cactus polysaccharide improved the erythrocyte function of tumor-mice, which may be one of anti-tumor mechanisms.

Animals↗
PubMed1993

[Immune function of rheumatoid arthritis treated by medicated-bath therapy in Tibetan medicine].

The changes of the immune function of rheumatoid arthritis before and after the Tibetan medicated-bath was observed. It showed a higher level of the rheumatoid factor (RF) titre, immunoglobulin (Ig) G, M, A and CD4 cells, but the CD8 cells was obviously lower before the treatment. Clinical data indicated that the medicated-bath had significant effective rate. In order to elucidate the mechanism of the medicated-bath upon rheumatoid arthritis the RF titre, Ig level, complement C3, 3H-TdR incorporated with lymphocytes transformation and CD3, CD4, CD8 cell level were assayed. Results showed that RF titre decreased after the bath and the negative transforming rate reached 70.6%, Ig level obviously dropped as well as the number of CD4 cells while CD8 cell level increased. The transforming stimulation index of lymphocyte cells obviously decreased. All of the above mentioned showed that there was a higher concentration of the enhancing factor of interleukin-2 (IL2-EF) involved in lymphocyte culture of rheumatoid arthritis patients. They suggested that the Tibetan medicated-bath had an immunomodulating effect on rheumatoid arthritis patients through increasing the level of CD8 cells and reducing CD4 cells.

Adjuvants, Immunologic↗
PubMed2004

Hormonal control of the yolk precursor vitellogenin regulates immune function and longevity in honeybees.

A striking example of plasticity in life span is seen in social insects such as ants and bees, where different castes may display distinct ageing patterns. In particular, the honeybee offers an intriguing illustration of environmental control on ageing rate. Honeybee workers display a temporal division of labour where young bees (or 'hive bees') perform tasks within the brood nest, and older bees forage for nectar, pollen propolis and water. When bees switch from the hive bee to the forager stage, their cellular defence machinery is down-regulated by a dramatic reduction in the number of functioning haemocytes (immunocytes). This study documents that the yolk precursor vitellogenin is likely to be involved in a regulatory pathway that controls the observed decline in somatic maintenance function of honeybee foragers. An association between the glyco-lipoprotein vitellogenin and immune function has not previously been reported for any organism. Honeybee workers are functionally sterile, and via the expression of juvenile hormone, a key gonotrophic hormone in adult insects, their vitellogenin levels are influenced by social interactions with other bees. Our results therefore suggest that in terms of maintenance of the cellular immune system, senescence of the honeybee worker is under social control.

Animals↗