Involution Of Lymphoid Organs Research Articles

Supplementing the feeds of layer pullets, at different ages with two different fiber sources improves immune function

Two experiments were conducted to study the effects of lignocellulose supplementation on immune function in layer pullets at different stages of growth. Four-wk-old pullets (Experiment 1) were fed a control, diet (Diet C); Diet C plus 1% mixed soluble/insoluble fiber (Diet MF), or plus 1% insoluble fiber (Diet IF). At 7.5 wk-of-age, heterophil phagocytosis, and oxidative burst in Groups MF (328.5 beads/100 cells; 4,330.0 ΔRFU; relative fluorescent units) and IF (350.3; 5,264.4) were greater (P < 0.05) than Controls (303.4; 3,509.0). At 8 wk-of-age, Group MF and IF relative weights of bursa of Fabricius (0.57 g/100 g BW; 0.58 g /100 g BW), thymus glands (0.77; 0.78), and areas of Peyer’s patches (PP) (2.7 cm2; 2.9 cm2) were higher (P < 0.05) than Controls (bursa, 0.50 g; thymus, 0.70 g; PP area, 1.8 cm2). In Experiment 2, 10-wk-old pullets were fed a control diet or diets containing 1.5% MF or IF for 8 wk. At 14 wk-of-age IF pullets had higher (P < 0.05) heterophil phagocytosis efficiency (447.9 beads/100 cells) than Controls (376.4) and MF and IF had greater (P < 0.05) oxidative burst (1,302.9 and 1,857.7 ΔRFU) than Controls (744.1). At 17 wk-of-age MF and IF had increased (P < 0.05) proliferation of T-lymphocytes (ConcanavalinA-stimulated) (100.4 and 103.1% of unstimulated cells) and B-lymphocytes (lipopolysaccharide-stimulated) (122.4 and 129.0) than Controls (ConA, 79.4; lipopolysaccharide, 106.6). At 18 wk-of-age, IF pullets were heavier (1,607.5 g, P < 0.05) than Controls (1,506.5 g), had heavier (P < 0.05) bursa of Fabricius (1.12 g) than MF and Control groups (0.98 g; 0.92 g) and cecal tonsils of MF (0.38 g) and IF (0.39 g) weighted more (P < 0.05) than Controls (0.33 g). Number of jejunal and ileal PP (10.0) in IF pullets was higher (P < 0.05) than Controls (7.1). These results indicate that both MF and IF can improve development of the immune system of young and grower pullets during periods of maturation and involution of lymphoid organs.

The protective effect of the Vacha rhizome extract on chronic stress-induced immunodeficiency in rat

Context: Chronic stress is an inevitable factor in the modern day society which affects cell mediated as well as humoral immunity. There is a need to prevent stress effects with traditionally used herbs.Objective: The present study was undertaken to investigate the immunoprotective effect of Vacha (Acorus calamus L. Acoraceae) rhizome under stressful condition.Materials and methods: Soxlet extraction of Vacha rhizome was performed with increasing polarity of solvents, i.e., petroleum ether to ethanol. The extract was concentrated by distilling off the solvent in flash evaporator and dried in desiccators. The benzene extract was found to have anti-stress property in our earlier studies and hence it was used in the present experiment. Extract was administered every day for 4 weeks orally to adult female rats prior to exposure to stress, restraint (1 h) and forced swimming exercise (15 min).Results: Vacha rhizome extract significantly prevented the stress induced reduction in total and differential leukocytes count, immunoglobulin content, bone marrow cellularity and viability, lymphocytes counts in lymphoid organs, islands of white pulp of spleen (ED50 = 10 mg, p < 0.001) and a significant increase in circulating immune complexes and apoptotic index of lymphoid organs (ED50 = 10 mg, p < 0.001) compared to controls.Discussion and conclusion: The present study clearly indicates that Vacha extract not only prevents stress-induced suppression of immunity and structural involution of lymphoid organs, but also boosts immunity in normal rats. Therefore, it is suggested that Vacha extract administration maintains normal immunity despite the body experiencing stress.

Involution of lymphoid organs in bottlenose dolphins (Tursiops truncatus) from the western Gulf of Mexico: Implications for life in an aquatic environment

Involution of lymphoid tissues in relation to age has not been defined for bottlenose dolphins (Tursiops truncatus). Twenty-five bottlenose dolphins from the coast of Texas and western Louisiana were examined and complete necropsies were performed with histological samples taken of nearly all tissues. Ages ranged from several days to 27 years. The histology of four lymphoid organs-thymus, pharyngeal tonsil, mucosa-associated lymphoid tissue (MALT) of the colon, and anal tonsil-was assessed. Numerical scores were assigned to specific morphological features, thus creating an involution score. Definable and scorable features of each organ were selected for evaluation and determination of loss of lymphoid elements. Neonatal dolphins were recorded as the reference standard for no involution. The highest score for each organ represented the greatest amount of retention of tissue elements. Thus, the lower the score, the greater degree of involution. Comparing involution scores to tooth age permitted an assessment of involution over time. The greatest degree of involution was found in the MALT of the colon. The MALT of the colon declined dramatically so that after age 10 it was absent from 4 of 14 animals and minimally present in 8 others. Thymic tissue also suffered a precipitous drop in volume after about age 5, but was found in animals up to 24 years of age. Involution was moderate and variable in both pharyngeal and anal tonsils. In some animals, these tissues were reduced in volume early, and prominent in others well into adult life (over 20 years).

Effects of immunostimulators on involution of lymphoid organs in mice exposed to heat and cold stress.

The effects of two immunostimulators, active egg white product (AEWP) and dihydroheptaprenol (DHP), on involution of lymphoid organs were investigated in mice exposed to heat and cold stress. Heat (37 degrees c, 45 min) and cold (4 degrees C, 4-24 hr for 4 days) stress induced involution of the thymus and/or spleen. AEWP was administered orally at a dose of 500 mg/kg for 4 consecutive days after exposure to heat stress or during cold stress. DHP was injected intramuscularly at a dose of 100 mg/kg on the 4th day after exposure to heat or cold stress. In mice exposed to heat and cold, the ratio of thymus to body weight was significantly higher in the AEWP- and DHP-treated groups as compared to the non-treated group (P < 0.01), also the ratio of spleen to body weight was significantly higher in the DHP-treated group as compared to the non-treated group (P < 0.01). These results showed that AEWP and DHP markedly alleviated involution of the thymus and/or spleen due to heat and cold stress.

The Effect of Malnutrition on Transplantation Immunity and Lymphoid Organs in the Edible FrogRana esculenta

Abstract Newly metamorphosed froglets of the edible frog Rana esculenta, i.e., interspecific hybrids of R. ridibunda and R. lessonae, were collected in the field. In the laboratory some of them were fed ad libitum while others were malnourished. After three weeks, each froglet received four skin grafts from four adult donors: R. esculenta, R. ridibunda, R. temporaria and Bombina variegata. Malnutrition impaired transplantation immunity to xenogeneic grafts but not to allogeneic and semixenogeneic ones. Seven weeks of nutritional deficiency caused involution of lymphoid organs, mainly thymuses, but also subcutaneous lymphoid bodies and spleens, as well as significant depletion of peritonealleukocytes.

Effect of cold stress on performance and immune responses of Bedouin and white leghorn hens

1. Bedouin chickens are kept in deserts mainly for eggs and are well adapted to arid conditions. However, deserts are also characterised by relatively cold winter nights. As a consequence of cold stress there is an involution of lymphoid organs and a depression of immunological function. We compared the performance and immunological responses of Bedouin and White Leghorn hens kept in outdoor pens in the Negev Desert during the winter. 2. Initial mean body mass was similar for the two breeds: 1525 g for Bedouin hens and 1542 g for White Leghorn hens. White Leghorns lost 7.74 g/d, compared with 0.60 g/d for Bedouin hens and produced 0.36 eggs/d, compared with 0.54 eggs/day for Bedouin hens. 3. The heterophil/lymphocyte ratio for Bedouin hens was 0.28, which was lower than the 0.44 for White Leghorn hens. Phagocytic index was higher in Bedouin hens than in White Leghorns. Furthermore, wattle index measured 24, 48 and 72 h after PHA injections and anti-SRBC antibody titres determined 10 d after challenge were also higher in Bedouin hens than in White Leghorns. 4. We concluded that the Bedouin hens were less stressed by the cold than were the White Leghorn hens.

Effects of castration and testosterone treatment on the development and involution of the bursa of Fabricius and the thymus in the Japanese quail

We investigated the effects of castration on the development of lymphoid organs (bursa of Fabricius, thymus, and spleen) in the Japanese quail during 4–8 weeks of age under a long photoperiod (16L:8D) and the effect of testosterone implantation on the involution of the lymphoid organs under long (16L:8D) and short (8L:16D) photoperiods. Under 16L:8D, the bursa of Fabricius and thymus in intact quail grew rapidly and reached a peak at 6 weeks of age and regressed thereafter. In contrast, development of the lymphoid orgas in castrated quail was well correlated with the body growth. Testosterone treatment induced a significant reduction in relative bursal weight to body weight at 6 weeks of age under 16L:8D and 8 weeks of age under 16L:8D and 8L:16D, in relative thymus weight at 6 weeks of age under 16L:8D and 8L:16D, and in relative spleen weight at 6 weeks of age under 8L:16D. Thus, we conclude that gonadal hormones play an important role in the development and involution of lymphoid organs.

Interaction of cholera toxin and toxin derivatives with lymphocytes. II. Modulating effects of cholera toxin on in vivo humoral and cellular immune responses.

The in vivo effects of cholera toxin on lymphoid organ structure and function in mice were investigated. It was found that within a day following intravenous injection of 1 mug of toxin, thymus as well as spleen weight decreased but the animals remained healthy. Histological studies suggested that the involution of lymphoid organs was due to cell death. Injection of cholera toxin into adrenalectomized mice was lethal within 36 h. In these animals no decrease in lymphoid organ weight was noted. Thymus cells from toxin-treated mice were found to be much inferior to thymocytes of untreated animals in their in vitro response to Concanavalin A, whereas the response of spleen cells from toxin-treated animals to mitogens was slightly increased. 1 mug of cholera toxin increased primary antibody formation when given to mice together with antigen (sheep erythrocytes) and decreased primary antibody formation when given before or after the antigen. The toxin also increased secondary antibody formation when injected simultaneously with or after the booster antigen dose, and decreased the antibody formation when given a few days before the booster injection. Treatment of mice with toxin was found to increase the capacity of spleen cells from these animals to induce the parental effect on antibody formation and to induce graft-versus-host reactions. The mechanisms behind the observed effects are discussed. It is suggested that cholera toxin affects different types of cells involved in immune responses primarily by a direct inhibitory action on cellular proliferation but also indirectly by causing release of adrenal gland hormones.

Antibody formation in first and second generation offspring of nutritionally deprived rats.

Prolonged partial restriction of calorie intake in young rats results in reduced growth, involution of lymphoid organs, and lymphopenia. After immunization with sheep red blood cells, the number of antibody-forming cells in the spleen and serum hemolysin titers are markedly reduced. The effect is more pronounced on the primary response and on immunoglobulin G antibody-forming cells. Significant impairment of antibody formation is detectable in the first (F1) and second (F2) generation offspring of starved Fo mothers.