concanavalin-a and Weight-Gain

The main aim of this study was to investigate the effects of different levels of feed restriction (FR) on immune responses of chicken lines divergently selected for high (H) and low (L) antibody responses to SRBC. We hypothesized that severe feed restriction suppresses immune responses and the level of immune suppression differs between birds with different genetic background. Therefore, we tested antibody responses, blood lymphocyte proliferative responses, and production of reactive oxygen intermediates (ROI) by Zymosan A-stimulated blood cells in chicken lines maintained on 3 levels of FR. The H line birds had significantly higher antibody responses, higher ROI production, and lower corticosterone (CORT) levels when compared with the L line birds. Feed restriction induced no significant effect on specific antibody responses to either a T helper 1- (Mycobacterium butyricum) or a T helper 2- (keyhole limpet hemocyanin) type antigen. Feed-restricted birds showed a marked reduction in natural antibodies binding lipoteichoic acid, in vitro lymphocyte proliferation in response to stimulation with concanavalin A, BW gain, and relative lymphoid organ weights compared with the birds fed ad libitum. However, FR birds showed a markedly enhanced ROI production, and plasma CORT levels compared with the birds fed ad libitum. The enhanced ROI production and suppressed lymphocyte proliferation coinciding with enhanced plasma CORT levels suggest stress-mediated immunomodulating effects of FR. A significant treatment by line interaction was found for ROI production; the increase of ROI production was larger in the H line than in the L line under severe FR. The increase in CORT levels was larger in the L line than in the H line under severe FR. Furthermore, the L line gained more BW than the H line under ad libitum conditions. Finally, under severe FR, relative spleen weight was lower in the L line than in the H line. The present findings suggest genetic differences affecting physiological and immunological responses under FR conditions.

Topics: Animals; Antibodies; Antibody Formation; Antibody Specificity; Bursa of Fabricius; Cell Proliferation; Chickens; Concanavalin A; Corticosterone; Food Deprivation; Hemocyanins; Immunity, Cellular; Immunity, Innate; Lymphocytes; Organ Size; Selection, Genetic; Spleen; Weight Gain

Garlic and garlic products are known to induce anti-inflammatory effects, but much of the research to date has focused on the inhibitory effect of garlic on the activity of mononuclear cells/macrophages. The effect of garlic on the balance of the two mutually inhibitory T helper cell subtypes, Th1 and Th2 cells, has hitherto received little attention. We thus studied the effect of supplementation with garlic oil on the activity of Th1 and Th2 cells. Rats were administered by gavage with garlic oil (10 - 200 mg/kg) or corn oil every other day for 2 weeks. Cervical lymph nodes were collected to assay the lymphocyte proliferation rate and the production of Th1 interleukin 2 (IL-2) and interferon gamma (IFN-gamma) and the Th2 cytokines IL-4 and IL-10 upon stimulation with concanavalin A. Garlic oil enhanced the lymphocyte proliferation rate accompanied by an elevated production of all four cytokines when given at a dose of 100 mg/kg. At 200 mg/kg, the production of IL-4 and IL-10 was further enhanced but IFN-gamma production was suppressed. The ratio of IFN-gamma to IL-4 was enhanced by 50 mg/kg garlic oil but suppressed by 200 mg/kg garlic oil. In conclusion, supplemental garlic oil has a dual effect on Th1-Th2 cell balance: an enhanced T cell response towards the Th1 type at low doses and towards the Th2 type at high doses.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Cell Proliferation; Concanavalin A; Cytokines; Dietary Supplements; Garlic; Interferon-gamma; Liver; Lymph Nodes; Male; Mitogens; Plant Oils; Plant Roots; Rats; Rats, Wistar; Spleen; Sulfhydryl Compounds; Th1 Cells; Th2 Cells; Weight Gain

A study was conducted to determine the effects of supplemental fish oil on growth performance and immune system characteristics of beef calves. The grazing phase (78 d) used 48 yearling crossbred steers (231 +/- 22 kg initial BW) grazing 0.45-ha mixed-grass pastures (four per treatment) supplemented with 1.82 kg/d (as-fed basis) of the diets. Diets consisted of 1) corn-based supplement; 2) corn-based supplement with 1.5% (as-fed basis) fish oil; 3) wheat midd-based supplement; and 4) wheat midd-based supplement with 1.5% fish oil. On d 78, all calves were bled by jugular venipuncture, and blastogenic response of peripheral blood lymphocytes to phytohemagglutinin, concanavalin A, and pokeweed mitogen was measured. Fish oil supplementation negatively affected ADG with the corn-based supplement, but it had no effect when added to the wheat midd-based supplement (base-supplement x fish oil interaction; P < 0.03). Isolated lymphocytes from calves fed the corn-based supplement with fish oil had a greater response to stimulation with concanavalin A than did lymphocytes from calves fed the corn-based supplement alone, but there was no effect of fish oil addition to the wheat midd-based supplement (base-supplement x fish oil interaction; P < 0.01). During the growing phase, the 48 steers (352 +/- 32 kg initial BW) from the grazing phase were moved to drylot pens and were stratified by BW and previous dietary treatment (three calves per pen; eight pens per dietary treatment) for a 56-d growing trial. Dietary treatments consisted of 1) control, and 2) the control diet with 3% (as-fed basis) fish oil. Calves supplemented with fish oil had decreased ADG, ADFI, and G:F (P < or = 0.02) compared with controls. Fish oil supplementation during the grazing phase modulated the immune system; however, the decreased growth performance associated with fish oil in both trials may limit its practical use as an immune stimulant.

Topics: Animal Feed; Animals; Cattle; Concanavalin A; Diet; Dietary Supplements; Eating; Fish Oils; Immune System; Lymphocytes; Male; Phytohemagglutinins; Pokeweed Mitogens; Random Allocation; Triticum; Weight Gain; Zea mays

Effects of different durations of cold stress (CS) and the time point of immunization relative to the CS of 3 chicken lines were studied. The first 2 chicken lines were divergently selected for high and low antibody responses, and the third was a random-bred control line. In 2 experiments, 26-d-old growing chicks of the 3 lines were feed restricted at 80% of ad libitum and subjected to CS of 10 degrees C for 7, 2, or 0 d. Birds were immunized with keyhole limpet hemocyanin (KLH) at -1, +1, +3, +5, or +7 d relative to the end of the CS treatment. Specific antibodies to KLH were determined. In addition, in vitro lymphocyte proliferation responses to concanavalin A (ConA) and KLH as measures of cell-mediated immunity, production of zymosan-induced reactive oxygen intermediates as a measure of phagocytosis, and BW gain as a measure of a production trait were determined. Significantly higher antibody responses to KLH were found in the high line as compared with the other 2 lines. Specific antibody responses to KLH were not significantly affected by the CS treatments. CS had a delayed effect on in vitro mitogen responses to ConA. In vitro lymphocyte proliferation responses to ConA were higher in the low line birds than in the other 2 lines. In general, 7 d of CS significantly enhanced cellular immunity to ConA in vitro, whereas the 2-d CS treatment had differential effects on lymphocyte proliferation to ConA, depending on the line of bird and the time of immunization. KLH-specific lymphocyte proliferation was enhanced by 2 d of CS at 28 d after immunization. Effects of various CS treatments and the time of immunization on the production of reactive oxygen intermediates were inconsistent. In addition, BW gain was negatively affected by CS. We concluded that the innate part of the immune system (phagocytes) responded immediately to CS with an as yet unexplained variability, irrespective of the genetic background. When CS was prolonged, the cellular adaptive immune response and, to some extent, the specific humoral immune response were also affected. The lack of line-by-treatment interactions suggested that the genetic background was a prominent factor for the magnitude of the specific immune response. Our data confirmed earlier studies that, under restricted feeding with simultaneous stress (energy demand for thermoregulation and growth), cellular immunity is more sensitive than humoral immunity. A negative correlation between BW gain and cellular immunity sugges

Topics: Animals; Antibodies; Antibody Formation; Chickens; Cold Temperature; Concanavalin A; Hemocyanins; Immunity, Cellular; Immunization; Lymphocyte Activation; Poultry Diseases; Reactive Oxygen Species; Selection, Genetic; Stress, Physiological; Weight Gain

Elemental diets cause intestinal atrophy and reduced intestinal integrity, which can lead to significant increases in intestinal permeability and bacterial translocation. Recently, several lectins have been shown to have trophic effects on the intestine.. We examined the effects of concanavalin-A and phytohaemagglutinin on cell proliferation and crypt fission throughout the intestine of mice fed on elemental diets.. Mice were randomized to chow fed, elemental diet, elemental diet plus concanavalin-A and elemental diet plus phytohaemagglutinin groups. Cell proliferation and crypt fission were estimated in microdissected crypts. Plasma gastrin and enteroglucagon levels were measured by radioimmunoassay.. Elemental diet feeding significantly decreased cell proliferation and crypt fission of the middle and distal small intestine and throughout the colon. Phytohaemagglutinin significantly increased the weight of the intestine, but concanavalin-A had little effect. Cell proliferation in the small intestine was significantly increased by both lectins. However, in the stomach and colon, only phytohaemagglutinin increased proliferation. Crypt fission in the colon was dramatically increased by phytohaemagglutinin. Phytohaemagglutinin increased the plasma gastrin level, but not the enteroglucagon level.. Lectins have significant trophic effects on the small intestine and colon of mice fed elemental diets, and these actions vary between different sites in the gastrointestinal tract.

Topics: Animals; Atrophy; Cell Division; Colon; Concanavalin A; Food, Formulated; Gastric Mucosa; Gastrins; Intestine, Small; Lectins; Male; Metaphase; Mice; Organ Size; Phaseolus; Phytohemagglutinins; Plant Lectins; Radioimmunoassay; Random Allocation; Stomach; Weight Gain

Effects of four levels of dietary linoleic acid (LA), an n-6 fatty acid, and four levels of alpha-linolenic acid (LNA), an n-3 fatty acid, and their interactions on immune responses in growing layer hens were studied. Immune responses were induced by injection with keyhole limpet hemocyanin (KLH) or Mycobacterium butyricum particles at 35 d of age. Antibody (Ab) responses were measured until 21 d after immunization. In addition, delayed-type hypersensitivity, lymphocyte proliferation, weekly feed intake, and BW gain were studied. At Day 7 after immunization, anti-M. butyricum titers in the M. butyricum-immunized hens were decreased by the increase of dietary LA (P < 0.05). In the period from 10 to 14 d after immunization, anti-KLH Ab titers in KLH-immunized animals were affected by the interaction of dietary LA with LNA (P < 0.01). High dietary levels of LA or LNA increased the anti-KLH Ab response. However, at high levels of dietary LA and LNA, anti-KLH Ab titers were not increased. In the same period, anti-M. butyricum Ab titers of M. butyricum-immunized hens were affected by the interaction of dietary LA with LNA (P < 0.05). At low levels of LA and LNA, increased LA levels decreased the Ab response, whereas increased LNA levels at low LA levels hardly affected the anti-M. butyricum response. At a high level of LA, increased dietary LNA increased the anti-M. butyricum response. In vitro proliferation of peripheral blood leukocytes after stimulation with concanavalin A (ConA) was higher in chickens with a high level of dietary LNA. Feed intake decreased when the dietary levels of LA or LNA increased. However, BW gain was not affected by dietary treatments. Feed conversion was more efficient in birds fed high levels of LA and LNA. The present study indicates that various factors affect the Ab responses. First, the interaction of n-6 and n-3 polyunsaturated fatty acids (PUFA) is more important than the separate effects of n-3 or n-6. Second, the actions of dietary PUFA were different between antigens of a different nature. Third was the nature of the antigen affects when dietary PUFA exert their actions and the persistence of these effects. The presence of these multiple factors affecting immune responses should be considered when comparing effects of dietary PUFA on immune responses.

Topics: alpha-Linolenic Acid; Animals; Antibodies; Antibodies, Bacterial; Antibody Formation; Antigens; Chickens; Concanavalin A; Dietary Fats, Unsaturated; Eating; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Female; Hemocyanins; Hypersensitivity, Delayed; Immunization; Linoleic Acid; Lymphocyte Activation; Mycobacterium; Weight Gain

The plant lectins, Concanavalin A (Con A) and Galanthus nivalis agglutinin (GNA) have been prefed to rats for 3 d pre- and 6 d postinfection with Salmonella typhimurium S986 or Salm. enteritidis 857. Con A significantly increased numbers of Salm. typhimurium S986 in the large intestine and in faeces, and severely impaired growth of the rats, more severely than is the case of infection with Salmonella typhimurium alone. Con A had much less effect on rats infected with Salm. enteritidis 857 only showing a significant increase in numbers in the colon, accompanied by intermittent increases of Salmonella in the faeces during the study. GNA significantly reduced pathogen numbers in the lower part of the small bowel and the large intestine of rats infected with Salm. typhimurium S986 and significantly improved rat growth. GNA had little effect on infection by Salm. enteritidis 857 with slight decreases in Salmonella numbers in the small intestine and large intestine and transient increases in the faeces.

Topics: Animals; Concanavalin A; Feces; Galanthus; Humans; Lectins; Male; Mannose-Binding Lectins; Plant Lectins; Rats; Salmonella enteritidis; Salmonella Infections, Animal; Salmonella typhimurium; Weight Gain

The purpose of this study was to characterize the impact of a low-fat (LF; 1% fat) diet, a high-fat (HF; 25% fat) diet, and a standard (SD; 5% fat) diet on immune and oxidative parameters in a 20% body surface area burn animal model fed ad libitum for 10 days postinjury. Although the mechanisms are poorly understood, the amount of dietary lipid in nutritional support has been shown to have immunomodulatory effects after burn injury. Burned mice fed the LF diet showed a normal response in activated splenocyte proliferation compared to burned animals that received the SD or HF diet. Animals fed the SD and HF diets presented increased production of nitric oxide and prostaglandin E2 response after burn injury, which is associated with inhibited splenocyte proliferation. The total thiol concentration in spleen cells from burned animals kept on the HF diet was significantly higher than that in unburned animals, while no increase in these oxidative parameters was observed in LF-fed burned animals. Moreover, the LF diet significantly reduced hepatic lipid peroxidation, as measured by malonaldehyde concentration, compared to the other two diets. These results suggest that the administration of a LF diet in mice after a burn injury prevents inhibition of in vitro splenocyte proliferation and reduces the intensity of oxidative stress.

Topics: Animal Feed; Animals; Burns; CD4-CD8 Ratio; Concanavalin A; Corn Oil; Diet, Fat-Restricted; Dietary Fats; Dinoprostone; Disease Models, Animal; Eating; Female; Immune Sera; Immunophenotyping; Lipopolysaccharides; Lymphocyte Activation; Mice; Mice, Inbred C3H; Nitric Oxide; Oxidative Stress; Receptors, Antigen, T-Cell; Spleen; Weight Gain

Natural or synthetic melanin (CAS 8049-97-6) is a high molecular weight heteropolymer, product of the enzyme tyrosinase, found to possess radical scavenging and antioxidant functions. It was of interest, therefore, to study in detail the possible anti-inflammatory and/or immunosuppressive properties of a melanin isolated from grapes. The inhibitory effect of melanin on carrageenin-induced edema, as well as on edemas produced by other phlogistics, was remarkable suggesting that melanin interferes with the prostaglandin as well as the leukotriene and/or complement system mediated inflammation. Grape melanin showed potent inhibitory effect on adjuvant induced disease (AID) in rat, suppressing significantly the primary inflammation and almost totally the secondary lesions of arthritis. Melanin under the present experimental conditions not only strongly inhibited the in vitro lipid peroxidation of rat liver microsomal membranes, but furthermore protected the in vivo hepatic peroxidation occurring in AID rats, demonstrating its antioxidant and cytoprotective properties. The serum proinflammatory cytokines IL-1, IL-6 and TNF-a and the serum globulin fraction were elevated in AID rats, parameters which were more or less normalised by melanin treatment in contrast to the reduced serum levels of IL-2 which were not affected. Similarly to other lipoxygenase inhibitors and hydroxyl radical scavenger NSAIDs, melanin treatment did not affect IL-1 neither increased the splenic mitogenic responses, unlike the classical cyclooxygenase inhibitory NSAIDs. The subpopulation Th1 (T4+ or T8+) of lymphocytes is mainly responsible for cellular immune responses and thus their possible inhibition by melanin could lead to suppression of the development of AID, a model for cell-mediated immunity. The effect of melanin on T-cells is exhibited by the reduced spleen mitogenic responses to a T-cell mitogen and the reduced serum levels of IL-2 of treated rats. In conclusion, grape melanin is an interesting anti-inflammatory and immunomodulating natural product which appears to have multiple cellular targets within the reticuloendothelial and immune system.

Topics: Adjuvants, Immunologic; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Experimental; Concanavalin A; Cytokines; Edema; Foot; Lipid Peroxidation; Melanins; Mice; Mice, Inbred BALB C; Mitogens; Organ Size; Phagocytosis; Plant Lectins; Rats; Rats, Inbred F344; Rosales; Spleen; Weight Gain

Broiler chickens were examined for the effects of low (400 IU/kg), standard (1,500 IU/kg), or high (15,000 IU/kg) dietary vitamin A (VitA) levels on immune responsiveness postimmunization to Newcastle disease virus (NDV). A control pair-fed group (1,500 IU/kg) was included to compensate for the reduced feed intake associated with diet containing the low level of VitA. Interdigital skin reactions to phytohemagglutinin (PHA) and CD4:CD8 T lymphocyte ratios were significantly reduced in chickens fed the low VitA diet, whereas their antibody responses to NDV were significantly increased as compared to birds that consumed the 1,500 to 15,000 VitA diet ad libitum. On the other hand, birds on the high VitA diet had reduced lymphocyte responses to concanavalin A and pokeweed, but not to PHA. No effect of dietary VitA was observed for natural killer activity, nor on levels of percentage of cells expressing Class II MHC antigens among groups that consumed feed ad libitum. The results indicated that both humoral and cellular immune responses were modulated by levels of VitA in the diet, and suggest that VitA-deficient chickens developed a T helper (Th)2 immune response, whereas the chickens fed highly enriched VitA diet showed a Th1 immune response.

Topics: Animals; Antibodies, Viral; Antibody Formation; CD4 Antigens; CD8 Antigens; Chickens; Concanavalin A; Diet; Dose-Response Relationship, Drug; Female; Histocompatibility Antigens Class II; Immunity, Cellular; Killer Cells, Natural; Liver; Lymphocyte Activation; Newcastle Disease; Newcastle disease virus; Organ Size; Phytohemagglutinins; Pokeweed Mitogens; Random Allocation; Spleen; T-Lymphocytes; Vitamin A; Weight Gain

The study was designed to assess neonatal immunity of chicks hatched from breeders fed diets supplemented with beta-carotene, canthaxanthin, lutein, or vitamin E. Broiler breeder birds were fed experimental diets consisting of control, 0.04% beta-carotene, 0.04% canthaxanthin, 0.04% lutein, 0.03% alpha-tocopherol acetate, or 0.04% beta-carotene plus 0.03% alpha-tocopherol acetate. Three weeks after initiation of experimental feeding, birds were vaccinated against Newcastle disease virus. Chicks hatched from the eggs of these breeders were used to determine the neonatal immune responses. There were no significant differences in weight gain and antibody titers of 3-wk-old chicks. 3H-Thymidine uptake by bursal lymphocytes when stimulated with tetrahydrofuran was significantly higher for the chicks hatched from breeders fed diets supplemented with vitamin E, or vitamin E plus beta-carotene, than in controls. 3H-Thymidine uptake by splenic lymphocytes when stimulated with concanavalin A and phorbol 12-myristate 13 acetate was significantly higher for the chicks hatched from breeders fed diets supplemented with vitamin E or beta-carotene alone, or vitamin E plus beta-carotene, than for the control chicks. Chicks hatched from hens supplemented with vitamin E had significantly higher antibody titers at 1 and 7 d of age than chicks from the control group. Vitamin E supplementation of breeder birds increased the immune response of their progeny.

Topics: Animals; Animals, Newborn; Antibodies, Viral; Antioxidants; beta Carotene; Canthaxanthin; Carcinogens; Cell Division; Cells, Cultured; Chickens; Concanavalin A; Diet; Female; Furans; Lectins; Lutein; Lymphocytes; Male; Maternal-Fetal Exchange; Newcastle disease virus; Pregnancy; Tetradecanoylphorbol Acetate; Thymidine; Tritium; Vitamin E; Weight Gain

Thirty-two beef heifers were used to examine the effect of dietary copper depletion and repletion on neutrophil and lymphocyte functions. Heifers allotted to the control group (C+; n = 8) were fed a basal roughage/concentrate diet with Cu-sulfate supplementation (Cu > or = 8 ppm). To induce a Cu deficiency (depletion phase d 0 to 60), treated (T; n = 24) heifers received a diet supplemented with sulfur (.3% of diet) and sodium molybdate to achieve a Cu:Mo ratio of 1:1.5. Liver biopsies were collected on d 0, 27, and 60. Despite random allocation, T heifers had lower initial liver Cu concentrations (P < .01) than C+ heifers. At the start of the repletion phase (d 0, equal to d 60 of depletion), treated heifers were allotted by liver Cu concentration to three treatments (n = 8/treatment): Cu sulfate (S; Cu = 10 ppm), Cu proteinate (P; Cu = 10 ppm), or a negative control (C-) that remained on Mo and S supplementation. During the repletion phase, livers were biopsied on d 0, 14, and 45. By d 45, both S and P heifers had greater (P < .05) liver Cu concentrations than C- heifers. For both depletion and repletion phases, no treatment differences were detected in liver Mo or S concentrations. Jugular blood was collected on d 0, 27, and 55 of the depletion phase and d 0, 13, and 42 of the repletion phase. Neutrophils were isolated and incubated with Staphylococcus aureus to determine neutrophil bactericidal capacity (NBC).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Biopsy; Cattle; Cells, Cultured; Concanavalin A; Copper; Female; Food, Fortified; Hematocrit; Liver; Lymphocyte Activation; Lymphocytes; Neutrophils; Phytohemagglutinins; Random Allocation; Staphylococcus aureus; Thymidine; Tritium; Weight Gain