SRBC Suspension Research Articles

In vivo immuno - and angiomodulatory effects of Aloe arborescens folii recentis extractum siccum (AAES) in mice

Abstract Introduction AAES is a powdered form of Biostymina, herbal medicinal product of Phytopharm Klęka S.A., a water extract of Aloe arborescens Mill. leaves. Aloe arborescens Mill. (woody aloe, tree-like aloe) is known to have several traditional medicinal properties including anti-inflammatory, immunomodulatory, antiviral and antimicrobial activity. Objective The aim of this work was to study the in vivo effect of AAES on cellular (leukocyte-induced cutaneous angiogenesis, LIA test, and proliferative response to PHA) and humoral (anti-SRBC antibody response) immunity in mice. Methods Balb/c mice were fed AAES from 0.5 to 75 mg/kg body mass for seven days before grafting their splenocytes intradermally to F1 (Balb/cxC3H) recipients (LIA test). Neovascular reaction was evaluated 72 h later in dissection microscope. Spleen cell cultures were incubated with 0.5, 1 and 2 μg/ml of PHA. After 48 h of incubation, tritiated thymidine was added. After further 24 h, cells were harvested (Skatron) and incorporation of tritiated thymidine was measured using Beta-scintillation counter. Balb/c mice were fed for 7 days with AAES, then immunized intraperitoneally with 5% SRBC suspension and 7 days later the antibody response was measured with hemagglutination test. Results Neovascular reaction was significantly higher in groups grafted with splenocytes collected from all AAES fed donors than from the controls. The proliferation of splenocytes taken from mice fed AAES at doses ranging from 0.5 mg/kg to 7.5 mg/kg was stimulated in all cultures. Suppression of proliferation was observed in cell cultures derived from mice fed with higher doses of AAES. Stimulation of anti-SRBC antibody production was seen in mice fed both 2.5 and 7.5 mg/kg dose of AAES. Conclusion Powdered form of Biostymina (AAES) might be useful in the treatment of patients with ischaemia of tissues and organs (myocardial infarction, stroke, necrosis) and in deficiency in the production of immune cells and growth factors (infections, chronic wound healing, ulceration and bone fusion).

Prolonged in vivo Stinging Nettle Treatment Impacts on Functional Capacity of Leukocytes in Immunologically Mature Chickens

Abstract: Objective: The experiment aimed at establishing the effects of an alcoholic Urtica dioica extract on the in vitro blastogenic response in antigen stimulated, immunologically mature chickens. Materials and Methods: Three equal groups (n=17) of 47 days old, Rock x Cornish chickens were subjected to oral administration of: a) 0.5 ml/chicken/day of an alcoholic stinging nettle extract (I), b) ml/chicken/day alcohol (II, solvent control), and c) 0.5 ml chicken/day water (III-environment control) for seven days. All birds were injected with 0.5 ml/bird of a 5% SRBC suspension (days 0 and 7). Leukocyte numbers (Burker Turk method) and their blastogenic capacity (blast transformation test) were monitored on days 0, 7 and 14. The specific response was evaluated against a SRBC lysate. Student’s t-test was used to evaluate the statistical significance of the differences. Results and Discussion: The leukocyte numbers increased to from 18,083.33 ±4,879.81/mm3 to 42,833.33±7,547.99/mm3 by day 14. in vitro responses to C. officinalis and E. angustifolia decreased while SRBC response increased in the nettle treated group. Conclusion: The results did not validate the implemented protocol for the alcoholic stinging nettle treatment. Other administration routes, schemes or dosages should be tested to improve the functional capacity of the leukocytes. Key words: Chicken, Immunologically mature, Leukocytes, Blast transformation, Nettle extract.

The Potential Role of Antigen Priming In Increasing the Overall Antimicrobial Resistance in Captive Silver Foxes

Abstract: Objective: We hypothesized antigenic priming should stimulate the humoral and cell-mediated adaptive immunity, further improved by vegetal extracts, alleviating the immune suppression induced by captivity stress in silver foxes. Material and Methods: One of two groups of adult silver foxes was sc primed and boosted 7 days later with a 5% SRBC suspension. Serum antibody titers (hemagglutination test) and circulating immune complexes levels (4.2% PEG precipitation) were quantified and ln of the antibody titers were calculated seven days later. An in vitro blast transformation test was carried out on blood samples using alcoholic extracts of C. officinalis, A. montana, S. officinale, Echinaceea spp. and immune stimulating compounds and glucose consumption was evaluated. The significance of the differences was interpreted by Student’s t-test. Results: Cells grew better in primed foxes versus the unprimed individuals (68.8±9.88 and 17.49±22.9). The primed animals reacted significantly (p< 0.001-p< 0.01) better to vegetal extracts (C. officinalis, E. angustifolia) and to thymus extract, selenium salts and bovine tuberculin. Anti-SRBC antibodies were highly variable (0.69 - 5.54). Conclusion: SRBC exerted a positive effect on both humoral and cell-mediated immune responses in silver foxes, supporting the enhancement of antimicrobial defense by booster vaccination and immune stimulating therapy. Key words: Silver Foxes, Antigenic Stimulation, Adaptive Immunity, Vegetal Extracts.

Investigating immunocompetence in Aseel, Kadaknath and White Leghorn chicken

The study aimed to investigate immunocompetence in Aseel, Kadaknath and IWH line of White Leghorn chicken maintained at this institute. Five to six weeks aged pedigreed 75, 55 and 100 chicks progenies of 8, 8 and 20 sires of these respective genotypes were immunized against 1% (v/v) SRBC suspension. Five dpi sera were analyzed through haemagglutination (HA) test to assess humoral immune response. Serum lysozyme and immunoglobulin-G (IgG) concentrations were assessed through agarose lysoplate and single radial immunodiffusion assay, respectively. The data were analyzed by least squares analysis of variance. The estimated corresponding means of HA titre, serum lysozyme and serum IgG concentrations were 10.84±0.18, 21.28±0.78 μg/ml and 24.23±2.05 μg/μl in Aseel, 11.62±0.21, 16.91±0.93 μg/ml and 15.70±2.44 μg/μl in Kadaknath, and 11.94±0.15, 9.42±0.68 μg/mland 10.27±1.79 μg/μlin IWH line of White Leghorn chicken. The estimates significantly varied among the three genotypes. The HA titre mean was higher in IWH line of WLH followed by Kadaknath and Aseel chicken; whereas serum lysozyme and serum IgG concentration means were higher in Aseel followed by Kadaknath and IWH line. Sire within genotype or sire and sex of the birds had nonsignificant effect on the traits. This information could be important while selecting birds for improvement in general immune responsiveness and the high immunocompetence in Aseel and Kadaknath might be exploited by their selective introgression in high productive but less immunocompetent chicken germplasms.

Estimating genetic parameters of immunocompetent traits in Rhode Island Red chicken

The study aimed to estimate genetic parameters of immunocompetent traits in Rhode Island Red (RIR) chicken. Five to six weeks aged pedigreed RIR chicks of a selected (79 chicks) and a control (74 chicks) line maintained at the Central Avian Research Institute were immunized against 1% (v/v) SRBC suspension. Sera collected on 5th day post immunization were analyzed through haemagglutination (HA) test to assess humoral immune response. Serum lysozyme and immunoglobulin-G (IgG) concentrations were assessed through agarose lysoplate and single radial immunodiffusion assay. The data were analyzed by least squares analysis of variance. The least squares mean estimates of serum lysozyme and IgG were significantly influenced by sires in the selected line, but any estimate was not affected by sex in any line. The selected line had more serum lysozyme than the control line, which contained more HA titre and serum IgG. The traits were heritable at a range of 0.105 to 0.398, and correlated with a low to high range (0.134 to 0.552) of genetic correlations and least to low range (0.007 to 0.170) of phenotypic correlations. The information generated could be important while selecting birds for improvement in general immune responsiveness.

Vegetal extracts influence in vitro on the cell-mediated immunity in carnivores depending on health status, target species and plant taxonomy

Impaired immune response in individuals subjected to various stress factors leads to disease or low protective responses following vaccination, therefore modern immunology is seeking for alternative immune stimulating compounds for which plants could represent a source. The aim of this study was to establish the influence of several ethanolic vegetal extracts on in vitro adaptive cell-mediated reactivity in wild (mink, n=70, silver foxes, n=22) and domestic (dogs, n=32) carnivores and compare the responsiveness of these species under physiological (antigen-primed) and pathophysiological (aleutian disase of mink) conditions. Mink and foxes were primed with a 5% SRBC suspension (0.5 and 1ml respectively), twice, 14days apart and blood was sampled on days 0 and 14, while untreated dogs were sampled only once. Ethanolic extracts of Calendula officinalis, Symphytum officinale, Arnica montana, Echinaceea angustifolia and Echinacea purpurea were tested for immune activity in whole blood cultures by the use of the in vitro blast transformation test, where cell growth was monitored spectrophotometrically, by the glucose consumption test and stimulation/inhibition indices (S/I) were calculated.E. angustifolia acted stimulating in Aleutian disease positive mink (S/I SRBC primed 76.75±12.52%, non-primed 19.58±18.07, p<0.001) and foxes (S/I primed 20.28±21.27%, non-primed 20.13±13.10), while S. officinale was most stimulating (3.85±1.37%) in dogs in a statistically supported manner (p<0.05).In conclusion, the results indicated the need of individualized immune stimulating therapies, based on species and health status in the studied species, with the prior identification of the most appropriate plant alcoholic extract for each species.

Effect of plant extracts derived from thyme on male broiler performance

The effect of dietary thyme-oil extract (TOE) supplementation on immune functions of broilers were assessed by feeding graded levels (50, 100, 200, or 400 ppm) of TOE to male broiler chicks during a 42-d feeding trial compared with negative- or positive-control diets. Dietary control treatments included a negative-control diet with no feed-additive supplementation and 2 positive-control groups supplemented with either virginiamycin or zinc bacitracin. In total, 300 1-day-old Ross × Ross male broilers were randomly assigned to 6 dietary treatments that consisted of 5 replicates of 10 birds each. On d 21 and 42, 2 birds from each replicate were killed by cervical cutting to measure the relative weights of spleen and bursa of Fabricius. At 25 d of age, chicks were injected with 0.5 mL of 10% SRBC suspension. Broilers fed with 200 ppm of TOE had heavier weights of bursa of Fabricius than those fed other dietary treatments at d 42 of age. Furthermore, dietary inclusion of 100 ppm of TOE resulted in higher (P < 0.05) total immunoglobulin response in primary antibody titer against sheep erythrocytes compared with other dietary treatments. On the other hand, diet modifications had no significant effect on blood leukocyte subpopulations and heterophil-to-lymphocyte ratio. These results suggest that dietary supplementation with TOE, especially at the level of 100 ppm, can improve immunological responses of broiler chicks.

Effects of dietary n-6:n-3 ratio on immune and reproductive systems of pullet chicks

The objective of this study was to examine the effects of dietary n-6:n-3 ratio on immune and reproduction systems of Leghorn pullet chicks. A total of 216 Hy-Line W-36 pullet chicks (1 d old) were randomly assigned to 3 diets (n-6:n-3 ratios of 10, 6, and 2) until 22 wk of age. The Optomega-50 (Optivite International Ltd., Nottinghamshire, UK) containing 50% salmon fish oil was used as an n-3 source. Pullets were injected with SRBC suspension at 6 and 9 wk and anti-SRBC titers were measured 7 and 14 d after each immunization. The antibody (Ab) titers for Newcastle disease (ND), avian influenza, infectious bronchitis (IB), and infectious bursal disease (IBD) were determined at 4, 6, 10, 14, and 18 wk of age. Pullets fed diet with the n-6:n-3 ratio of 2 had higher feed consumption and lower BW gain (P < 0.05) compared those fed diets with the ratios of 6 and 10. The results demonstrated that the different dietary n-6:n-3 ratios did not have a significant effect on the anti-SRBC titers in pullets serum (P > 0.05). The Ab production against avian influenza vaccine was increased in pullets fed diet containing the n-6:n-3 ratio of 10 at wk 10 and 14 and increased for ND at only 14 wk (P < 0.05). On the other hand, the Ab response to IBD (14 wk) and IB (14 wk) vaccines was increased when pullets were fed diet containing a ratio of 6 (P < 0.05). The pullets fed diet with the n-6:n-3 ratio of 2 showed lower egg production and late sexual maturity (P > 0.05) whereas ovary weight (P = 0.01) and number of large yellow follicles (P = 0.049) were significantly decreased at first oviposition. Our results revealed that the supplementation of Optomega-50 as a source of n-3 to decrease the n-6:n-3 ratio in diet significantly increased Ab production for ND, IB, and IBD in pullet chicks with slight reduction in reproductive organs weight at early production.

Memory Antibody Responses of Broiler and Leghorn Chickens as Influenced by Dietary Vitamin E and route of Sheep Red Blood Cell Administration

Influences of dietary levels of vitamin E fed to hens and their progeny, and routes of SRBC inoculation on antibody responses of diverse populations of chickens were studied. Populations were a commercial broiler sire line (C), 2 commercial broiler dam lines (A and B), and Leghorn lines selected for high (H) or low (L) antibody response to SRBC. Dams from lines A and B were fed diets supplemented with either 10 or 300 IU/kg of vitamin E, whereas dams from lines H and L received only the diet with 10 IU of vitamin E/kg. Progeny from matings of C males with A and B females as well as H and L females mated to males from their respective lines were hatched on the same day and fed diets supplemented with either 10 or 300 IU/kg of vitamin E. Breeders were the same age and eggs were incubated in the same machine. Chicks were inoculated on d 14 intravenously with 0.1 mL of a 0.5% suspension of SRBC or intramuscularly with 0.1 mL of a 25% suspension of SRBC. Antibody response was measured 6 and 14 d later. Chicks received a booster i.m. inoculation of 0.1 mL of 25% SRBC on d 28. Titers were again measured 6 and 14 d later. Level of vitamin E fed to dams did not affect progeny BW or plasma vitamin E levels. Although titers were higher following i.v. than i.m. inoculation, the degree of difference varied among stocks. Dietary vitamin E level interacted with inoculation route with a greater response to the higher than lower level of vitamin E for i.v., but there was no difference for i.m. There were stock × level of vitamin E and stock × route of inoculation interactions for secondary responses to SRBC inoculation. Stock rankings after the first inoculation were not predictive of the rankings after the second inoculation. The 30-fold increase in dietary level of vitamin E resulted in >12-fold differences in plasma levels of vitamin E. Overall, there was a stock-dependent influence of dietary vitamin E on growth and humoral antibody response.

Effect of Xylitol Feeding on Antibody Production and Inflammatory Responses in Broiler Chicks

Effect of dietary xylitol on antibody titers to sheep blood red cells (SRBC) and immunoglobulin (Ig) G concentration in plasma and concanvalin A stimulated-blood T cell proliferation was studied in broiler chicks. In addition, changes in feed intake, and plasma acute phase proteins concentration such as alpha-1 acid glycoprotein and ceruloplasmin following single injection of lipopolysaccharide (LPS, Salmonella enteritidis, 1.5mg/kg body weight) were also determined. Male broiler chicks (8 days of age, Ross strain) were fed either diet containing glucose or xylitol for 22 days. A SRBC suspension (5 : 100, v/v) in a phosphate buffer was intravenously injected at 15 and 25 days of age and a blood sample was obtained at 21 and 29 days of age from wing vein. Thereafter, chicks were intraperitoneally injected with LPS and blood was obtained 0, 9 and 24 hours after the injection. Growth performance for 22 days before the LPS injection did not differ between dietary groups. The antibody titers against SRBC and plasma IgG concentration were greater in chicks fed the xylitol diet than those in chicks fed the glucose diet at 21 days of age, but not at 29 days of age. Proliferation of T cell induced by Con A before the injection of LPS did not differ in dietary treatments. Significantly greater feed intake during 24 hours following LPS injections was observed in chicks fed the xylitol diet relative in chicks fed the glucose diet. Acute phase proteins concentration in plasma at 9 and 24 hours following single injection of LPS did not differ in chicks fed the xylitol and glucose diets, except ceruloplasmin concentration at 9 hours after LPS injection. The results suggested that dietary xylitol enhanced antibody production without impairing growth performance, and alleviated reduction of feed intake without impairing early inflammatory responses even when they were received relatively high level of immune stimulation.

Augmentation effects of lymphocyte activation by antigen-presenting macrophages on FDG uptake

Research on FDG-uptake by blood cells has revealed that FDG is incorporated by macrophages and granulocytes, as well as activated lymphocytes. These characteristics of FDG suggest the possibility of visualizing the distribution of immunocytes in target organs. The aim of this study was to investigate if mouse spleen-derived lymphocytes, activated by macrophages presenting sheep red blood cell (sRBC) antigens, could be traced by FDG. One percent of a sRBC suspension was injected into the peritoneal cavity of mice thereby creating immunity to the sRBC antigen. The splenocytes, consisting mostly of lymphocytes, were isolated, and serum containing the anti-sRBC antibody was mixed with sRBC to prepare sRBC-antibody complexes (sRBC-AbCs). Then five percent of a thioglycolate medium was injected into the peritoneal cavity of the same mice, and macrophages of ascitic cell origin were obtained. These macrophages were added to the sRBC-AbCs to induce sRBC antigen presenting macrophages. These were incubated with splenocytes obtained from sRBC immunized mouse (sRBC immunized splenocytes) or non-immunized splenocytes to induce a T cell immune response. [3H]deoxyglucose ([3H]DG) and FDG were incorporated in splenocytes, and the quantity of their uptake was measured. [3H]DG uptake by sRBC-immunized splenocytes was about eleven times as high as that of non-immunized splenocytes. In contrast, [3H]DG uptake by sRBC-immunized splenocytes, co-cultured with macrophages phagocytizing sRBC-AbCs, was about 40 times higher compared with non-immunized splenocytes. Splenocytes in non-immunized mice picked up very little [3H]DG, despite co-culture with macrophages phagocytizing sRBC-AbCs. Similar tendencies were observed with FDG. These results suggest that the SUV calculated in PET reflects not only the number of lymphocytes, but also the activation state of the lymphocytes themselves. In addition, the biodistribution of antigen specific lymphocytes, that have been taken up FDG in vitro and returned to the body, can be observed through PET.

PARAMETERS OF THE IMMUNOLOGICAL PROFILE IN CHICKENS TREATED WITH A CALENDULA OFFICINALIS EXTRACTION

Tests were carried out on thirty, 42 days old Rock x Cornish chickens, divided into three experimental groups: I - control injected with saline, II - injected with a Calendula officinalis extraction supplemented with Bayol and III - treated with Bayol. The effects of the in vivo treatments and simultaneous antigen priming (0.5 ml of a 5 % suspension of SRBC) on their humoral (lysozyme, anti-SRBC antibodies) and cell-mediated (leucocyte blast transformation) responses were investigated. Lysozyme (51.50 ± 32.30, 56.80 ± 41.27, 29.50 ± 22.73 μg/ml)(p<0.05), and anti-SRBC antibody titers (2.35 ± 0.86, 2.05 ± 0.65 and 1.90 ± 0.55) were the lowest in Bayol treated group. Spontaneous stimulation index was positively influenced by the in vivo Bayol therapy (57.20 ± 8.88 per cent), when compared to that recorded for the other groups (31.06 ± 18.93 group I, 33.37 ± 19.26 group II).

Effect of Route of Inoculation on Humoral Immune Response of White Leghorn Chickens Selected for High or Low Antibody Response to Sheep Red Blood Cells

Effects of route of SRBC inoculation and antigen dosage on primary and secondary antibody response of White Leghorn lines selected for high (HA) or low (LA) 5-d antibody response to a single i.v. inoculation with 0.1 mL of a 0.25% suspension of SRBC were studied in two trials. In the first trial, chicks from parents of generation S24 of each line were randomly assigned to one of four treatments. At 35 d of age, they were inoculated into the brachial vein with 0.1 mL of 0.25% suspension of SRBC or into the breast muscle with 0.1 mL of 0.25, 2.50, or 25.00% SRBC. Plasma SRBC antibody was measured 3, 6, 10, and 20 d later. In the second trial, chicks from parents of generation S25 of each line were randomly assigned to treatment groups. At 28 d of age they were inoculated with 0.1 mL of 0.25% SRBC into the brachial vein, 0.1 mL of 25.00% SRBC into the thigh (T-L) or breast muscle (B-L), or 0.5 mL of 25.00% SRBC into the thigh (T-H) or breast muscle (B-H). Twenty-one days later, chicks (except five per group) were given a booster inoculation of 0.1 mL of 25.00% SRBC into the thigh muscle. Six and 10 d after each inoculation, plasma SRBC antibody, IgG, and IgM titers were measured.The SRBC antibody titers after primary i.v. inoculation with SRBC were always higher for HA than LA chicks. When inoculations were i.m., differences between lines varied with dosage. Low dosages inoculated into the breast failed to induce line differences consistently, whereas at higher dosages, titers were greater for HA than LA chicks regardless of inoculation site. For Line LA, inoculation into the thigh elicited higher titers than inoculations into the breast. Antibody titers to the booster inoculation of SRBC were similar for the lines.

Immune Competence of Chicks from Two Lines Divergently Selected for Antibody Response to Sheep Red Blood Cells as Affected by Supplemental Vitamin E

Effects of dietary vitamin E on responses to SRBC antigens and Escherichia coli infection were studied in chicks from White Leghorn lines selected for 24 generations for high (HAS) and low (LAS) antibody responses to SRBC. Chicks were fed corn-soybean diets consisting of either high (300 IU per kg feed) or low (10 IU per kg feed) concentrations of vitamin E from the day of hatch through the end of experiment. The LAS chicks were heavier than the HAS chicks at 14 d of age and thereafter; there was no difference in BW between vitamin E concentrations. At 37 d of age, chicks were inoculated via the brachial vein with 0.1 mL of 0.25% SRBC suspension. Antibody titers at 6 and 10 d after inoculation were higher in HAS than in LAS chicks. At 6 and 10 d after inoculation with SRBC, antibody responses were lower in LAS chicks fed the diet containing the higher vitamin E concentration than in those fed the diet containing the lower concentration of vitamin E. At 64 d of age, chicks were injected in the posterior thoracic air sac with 0.1 mL of 10−2 or 10−4 dilution of Escherichia coli and scored for pericardial and air sac lesions. The HAS chicks were more susceptible to E. coli infection than LAS chicks as measured by lesion scores and BW changes. Although dietary vitamin E had no effect on lesion scores in either line, BW loss at 24 h after E. coli inoculation was significantly reduced in HAS chicks fed the higher concentration of vitamin E. The dosage of E. coli had no effect on lesion scores and BW changes. These results suggest that genetic selection might have changed immune competence in relation to responses to dietary vitamin E, and the optimum dietary concentration of vitamin E depends on genotype, among other factors.

Antibody responses to different dosages of sheep red blood cells in lines of chickens selected for high and low antibody response to sheep red blood cells

Temporal patterns of SRBC antibody response after primary and secondary inoculations were measured in White Leghorn males from lines selected 24 generations for high (HA) or low (LA) 5-d antibody titers to an i.v. inoculation with 0.1 mL of a 0.25% suspension of SRBC. Primary i.v. inoculations were administered at 50 d of age as 0.1 mL of either 0.025 or 0.25% suspension of SRBC. Antibody levels of SRBC were measured 3, 5, 7, 9, 11, 13, and 20 d after inoculation. Also, IgG levels were measured on samples obtained 3, 7, 13, and 20 d after inoculation. At 70 d of age, half of the cockerels in each line-dosage subclass were given a booster inoculation of 0.1 mL of 0.25% SRBC. The SRBC antibody was measured 3, 6, 9, and 13 d later in chicks both receiving and not receiving the second inoculation. Patterns of antibody response to SRBC dosage differed according to line, resulting in interactions of line by dosage by day. Concentrations of IgG were greater for Line HA than for LA at 7 and 11 d after inoculation with SRBC but not at 3 and 20 d. Antibody responses to the booster inoculation differed between lines with a dosage effect present for LA but not for HA chicks. The greater anamnestic response observed in LA than in HA chicks is explained in the context of the resource allocation paradigm.

Effect of Heat and Cold Stress on Humoral Immunity in Mice

Firouzi, R. and Motamedifar, M. 1999. Effect of heat and cold stress on humoral immunity in mice. J. Appl. Anim. Res., 16: 75–80. To evaluate the influence of low and high environmental temperatures on primary response in humoral immunity in mice, four experiments using 108 Swiss outbred mice were conducted. Test mice were immunized with an intraperitoneal injection of 5% suspension of SRBC and control group ones were injected with both SRBC and normal saline. Different groups of mice were exposed to heat or cold, as stressor either before or after immunisation. Stress regimens included four periods of 45 minutes exposure to heat (40±2C) or cold (4±2C) with 15 minutes intervals every day for one week. Antibody titers were determined using a microtiter hemagglutination assay. The results demonstrated a significant enhancement of antibody titer in mice which were exposed to cold stress before (P<0.01) and after (P<0.05) immunisation as well as the heat stress before immunisation (P<0.05), while heat stress after immunisation decreased antibody titer significantly (P<0.05).

Diet and immunological memory of lines of White Leghorn chickens divergently selected for antibody response to sheep red blood cells

Antibody responses to a first, second, and third injection with SRBC, and growth were studied in lines of White Leghorn chickens selected for high (HA) or low (LA) 5-d antibody titers to an i.v. inoculation with 0.1 mL of a 0.25% suspension of SRBC. The experiment involved parallel studies on two groups of chicks hatched from the same matings of parental lines HA and LA at a 14-d interval. Chicks of each age-line subclass were fed either a high or low nutrient density diet from hatch onwards. When chicks of Hatches 1 and 2 were 28 and 14 d of age (doa) respectively, they were injected with 0.1 mL of 0.25% suspension of SRBC, and antibody titers measured 3 and 6 d later. A second and a third injection of the same concentration of SRBC was given to chicks of each age-line-diet subclass at 10-d intervals and antibody titers measured 3 and 6 d after each injection in different chicks randomly sampled from each age-line-diet subclass. After the first injection, antibody (primary) responses of HA chicks were higher than those of LA chicks regardless of age and diet. This difference (HA > LA) observed for the primary response was seldom evident in the responses to the second (secondary) and third (tertiary) injections. Antibody responses of LA chicks after the second and third injections were anamnestic. For HA chicks given the first injection at 28 doa, neither the secondary nor tertiary responses suggested anamnestic capacities, whereas there was apparent memory exhibited by the secondary and tertiary responses of HA chicks initially injected at 14 doa. The LA chicks were significantly heavier than HA chicks at all ages. Even though the higher nutrient density diet increased BW of chicks of both lines, its effect on memory responses was sporadic. The results of this experiment show that, even though divergent selection has been successful in the primary responses, correlated responses in immunological memory were not always observed, suggesting that the two types of responses might be under different genetic control.

Group Selection for Adaptation to Multiple-Hen Cages: Humoral Immune Response ,

A selected line of White Leghorns, which has shown improved survivability and reduced feather loss in large multiple-hen cages, was evaluated for humoral immune response to SRBC under both stressed and unstressed conditions. Three lines of chickens (selected, control, and commercial) were housed in either single- (1 hen) or multiple-hen cages (12 hens, social competition) and subjected to a cold ambient temperature (0 C) at 33 wk of age and to two heating episodes (38 C) at 44 wk of age. Each hen was challenged intravenously with 1 mL of a 7% saline suspension of SRBC at the time that cold exposure was initiated. Hens subjected to high ambient temperatures had been exposed previously to a cold temperature, but were not challenged with SRBC until 16 to 18 h following the end of the second heating episode.Exposure to cold caused immunosuppression in single-caged hens, but not in hens in colony cages. Single- vs colony-caged hens of the control environment challenged with SRBC at 33 wk of age had similar primary hemagglutinin responses to SRBC. Hens subjected to heat experienced immunosuppression at 9 and 12 d following challenge to SRBC when compared to the controls. Hens of multiple-bird cages challenged with antigen at 44 wk of age had a significantly lower hemagglutinin response to SRBC than those reared in single-bird cages. The three lines of genetic stock had similar primary hemagglutinin responses to SRBC; the interactions of genetic stock with cage size or environmental temperature were not significant. It was concluded that genetically selecting hens for survival in multiple-hen cages did not affect their humoral immune response to SRBC.

Growth, Immunoresponsiveness, and Disease Resistance of Diverse Stocks of Chickens Reared Under Two Nutritional Regimens

Growth, immunocompetence, and disease resistance were measured in a commercial broiler stock (BC), a commercial white-egg-layer stock (LC), and a White Plymouth Rock line selected for high juvenile BW (HW) under dietary regimes differing in protein and energy content. Diet E had 20% more protein and 17% more ME than Diet A. Stock by sex interactions were significant for BW at 28 and 36 d of age because sexual dimorphism occurred at younger ages in the meat than in the layer stocks. When inoculated with .1 mL of a .25 or 2.50% suspension of SRBC, diet by stock interactions were significant for antibody titers 6 d postinoculation (PI) at the lower dosage. Interactions were not present at the higher dosage or for either dosage 13 d PI. Diet by stock interactions were significant at both dosages for change in SRBC titers from 6 to 13 d PI. The interactions resulted from a significantly smaller decline in BC than HW or LC chicks fed Diet A, whereas all stocks responded similarly when fed Diet E. A significant decline in rate of BW gain was observed in chicks inoculated with marble spleen disease virus (MSDV), with the increase in relative weight of spleen significantly greater for LC than HW or BC chicks 6 d PI. When heterophil to lymphocyte ratios were used as an assay of response to MSDV challenge, ratios were significantly higher for HW chicks fed Diet A than for chicks fed Diet E and for LC chicks fed Diet E than for chicks fed Diet A, but not different for BC chicks on the two diets.

Evidence Against the Induction of Immunological Tolerance by Feeding Antigens to Chickens

A series of studies was conducted to determine whether oral tolerance shown to be inducible in rodents can be induced in chickens. A preliminary study was performed with male juvenile Sprague-Dawley rats to ascertain the ability of ELISA to detect oral tolerance induction. Two groups of six rats were provided water with or without 2 mg/mL BSA for 14 consecutive d to induce tolerance. Eight days following water treatment, the rats were challenged i.m. with 1 mg BSA. Serum collected from the rats 20 d later showed decreased (P < .01) anti-BSA ELISA titers in the group given BSA in the water relative to those given ordinary water. Three experiments were conducted to determine whether oral tolerance could be induced in chickens. Birds were given daily oral doses of 25 mg BSA for 14 d (Experiment 1), or fed 5% casein in their diet for 14 d (Experiment 2), or 1 mL of a 50% suspension of SRBC for 10 d (Experiment 3). All birds were challenged with the same antigen after oral dosing. Birds orally dosed with BSA prior to challenge with BSA had titers similar to birds not fed BSA prior to challenge with BSA. When chickens were fed casein (P < .05) or orally gavaged with SRBC (P < .1), titers were enhanced. These observations suggest that feeding antigens prior to injection with the same antigen leads to an enhanced humoral immune response in birds and not tolerance.