B and T lymphocytes in the bovine mammary gland: Rosette formation and mitogen response

Characterization of lymphocyte subpopulations in the bovine mammary gland was accomplished using cells obtained from dry secretions. Correlation of cell surface properties with functional capacity was attempted by assaying the ability to form erythrocyte-antibody (EA) rosettes, erythrocyte-antibody-complement (EAC) rosettes, and sheep erythrocyte (E) rosettes and the ability to respond to phytohemagglutinin (PHA), Concanavalin A (Con A), and pokeweed mitogen (PWM) in the lymphocyte stimulation test. Results were compared with those obtained for peripheral blood lymphocytes (PBL) from the same animals. Mammary gland lymphocytes (MGL) formed significantly fewer (p < .01) EA and EAC rosettes, but significantly greater (p < .01) E rosettes compared to PBL. MGL were significantly less responsive (p < .05) to mitogens than were PBL. MGL contained a large proportion of T lymphocytes, which do not respond to T lymphocyte mitogens in culture.     

Molecular studies of T-lymphocytes from cattle infected with bovine leukemia virus

Although bovine leukemia virus (BLV) is mainly associated with infections of B-lymphocytes, we have previously reported the statistically significant increase in the T-lymphocytes obtained from BLV-infected asymptomatic aleukemic (AL) cattle. In this report the presence of BLV provirus in the DNA of immunoaffinity purified T-lymphocytes from AL animals was assessed using a highly specific radiolabelled (32P) BLV-DNA provirus probe and solid phase DNA hybridization. The BLV provirus was found in the DNA of the peripheral blood mononuclear cells of all AL animals tested and three of the four purified T-lymphocyte preparations from these animals. The purified T-lymphocyte preparations used in this study contained less than 4% detectable B-lymphocytes. One animal had no detectable B-lymphocytes in the purified T-lymphocyte preparation and the DNA from these cells also gave positive hybridization results. The lymphocyte blastogenesis assay was then used as an indicator of the functional ability of lymphocytes from these BLV-infected AL cattle to respond to mitogenic stimuli. The responsiveness of lymphocytes from these animals to the mitogens concanavalin A (Con A), phytohemagglutinin (PHA), and pokeweek mitogen (PWM) was comparable to that of lymphocytes from BLV-negative animals when changes in 3H-thymidine uptake (c.p.m.) were used as measurement of mitogenic-induced blastogenesis. This indicated that infection of the T-lymphocytes by BLV does not appear to alter the overall response of the lymphocyte populations to mitogenic stimuli. High levels of spontaneous blastogenesis in the absence of mitogenic stimulation were observed for lymphocyte preparations of AL animals. The reason for this proliferation of lymphocytes is unclear; however, sera from these AL animals were found to contain a blastogenesis-augmenting factor(s) when added to lymphocytes from BLV-negative control animals in the presence of Con A, PHA and PWM.     

Evidence of decreased concanavalin A induced suppressor cell activity in the peripheral blood and pulmonary lymph nodes of sheep with ovine progressive pneumonia

Concanavalin A (Con A) induced suppressor cell activity was evaluated in a group of ovine progressive pneumonia virus-antibody positive sheep (OPPV+). Decreased levels of suppressor activity were observed in the peripheral blood and regional pulmonary lymph nodes of animals with clinical and pathological evidence of ovine progressive pneumonia (OPP) when compared to animals with no lesions and animals with caseous lymphadenitis involving the lungs and pulmonary lymph nodes. Decreased levels of Con A stimulated lymphocyte proliferation was also observed in the peripheral blood and iliac lymph nodes of sheep with OPP. Sheep with OPP were found to be hypogammaglobulinemic. Sera from OPPV+ sheep had no effect on T and B cell mitogen stimulated responses of lymphocytes from sheep seronegative for antibodies to ovine progressive pneumonia virus (OPPV-) when compared to normal sheep serum.     

Effect of shearing on the incidence of caseous lymphadenitis in Awassi sheep in Jordan

A total of 876 sheep from five flocks in north Jordan were selected to study the effect of shearing on the incidence of caseous lymphadenitis (CLA). The animals were divided into two age groups, sheep aged 1-2 years and those aged > or = 3 years. Blood samples were collected from the animals at the time of shearing and again 6 months later. A toxin enzyme-linked immunosorbent assay was used to identify sheep that had been infected with Corynebacterium pseudotuberculosis. The point prevalences of CLA were 6.59% and 21.06% in the 1-2-year and > or = 3-year age groups, respectively, and were significantly higher (P < 0.01) in the > or = 3-year age group. The overall prevalence among all ages was 15.3%. In the shorn sheep, the incidence of CLA was 22.46% and 9.47% in the 1-2-year and > or = 3-year age groups, respectively, and was significantly higher (P < 0.05) in the 1-2-year age group. In the control animals, the incidence was 8% and 5.26% in the 1-2-year and > or = 3-year age groups, respectively, and was different (P < 0.01) between the shorn (22.46%) and control (8%) animals of the 1-2-year age group. An epidemiological survey of 35 sheep farms revealed the prevalence of CLA, shearing wounds and unhygienic conditions during shearing in all farms. In conclusion, the prevalence of CLA increases with age and the incidence increases only in young sheep after shearing. Sheep are sheared under unhygienic conditions, which may be a contributing factor in increasing both the prevalence and the incidence of CLA.     

Molecular characterization and prevalence of cystic echinococcosis in slaughtered water buffaloes in Turkey

The present study was carried out between March 2006 and June 2010. During the study nine abattoirs were visited and 166 water buffalo internal organs were examined in Black Sea Region of Turkey. It was found that 10.24% buffaloes were infected with cystic echinococcosis (CE). The rate of CE found as 3.77% in males and 21.66% in females, 37.93% in older and 4.38% in young animals. The degree of prevalence according to age and sex was statistically significant (p<0.05). CE was observed 29.41% only in liver, 47.06% only in lungs and 23.53% in both liver and lungs. Therefore, the lungs were the predominant sites of the CE in buffaloes. Molecular identification on nine isolates, based on mitochondrial cox1 sequencing analyses, revealed that six cysts belonged to G1 genotype (domestic sheep strain) while 3 samples showed variant genotypes of Echinococcus granulosus complex G1-G2-G3. Two of them showed a thymine in position 52, like G2 strain, but the rest of sequences were completely identical to strain G1; also one specimen showed a single nucleotide change compared to strain G1 (C122T).     

Ultrastructure of blood lymphocytes in dairy cows with chronic lymphocytic leukemia

The morphology of blood lymphocytes was studied ultrastructurally in cows with chronical lymphocytic leucosis (CLL) and in healthy controls. A significantly higher occurrence of the so-called nuclear pockets in the leucaemic lymphocytes was found (13.8% v. 0.83% in healthy animals). The surfaces of lymphocytes were stained with ruthenium red; this showed the possibility of differentiating two distinct populations of lymphocytes in peripheral blood. In this way, a prevalence of B-lymphocytes, constituting 89.7% of all lymphocytes, was demonstrated in animals suffering from CLL.     

Importance of the hour of sampling in the lymphoblastic transformation assay of sheep peripheral blood lymphocytes

This paper describes the effect of the nycthemeral cycle on the lymphocyte response of sheep to different mitogens (PHA, Con A and PWM). A considerable decline in the lymphocyte response was evident in the afternoon and early in the morning in all 6 animals tested. Three peak responses were identified during a 24 hour study period, at 14.00 h, 24.00 h and 08.00 h. The results presented here suggest that this variation in lymphocyte response is a meaningful difference in the response ability of individual lymphocytes. Factors affecting the number of leukocytes and the proportion of different types of lymphocytes in peripheral blood might be the essential causes of variation. To obtain an accurate indication of an individual's immunocompetence, it is important to make a preliminary determination of the optimal hour for sampling. If this is not possible, all the samples must be taken at the same hour on each test day, in order to make significant comparisons.     

全株玉米青贮和谷草干草不同比例组合对杜湖杂交肉羊增重、屠宰性能与育肥效益的影响

为探讨全株玉米青贮(WCS)和谷草干草(MH)日粮粗饲料不同比例组合对杜×湖杂交肉羊生长、屠宰性能以及经济效益的影响。挑选体况相近的60日龄杜泊羊和湖羊杂交F1代公羔羊60只,分为A组(WCS:MH=100:0)、B组(WCS:MH=60:40)、C组(WCS:MH=20:80)、D组(WCS:MH=0:100),每组设置5个隔栏,按每个隔栏3只羊单独投料测定采食量,每隔14 d对羊只进行称重,饲养84 d出栏进行屠宰。结果表明:随着谷草替换比例升高,B、C、D组与A组相比干物质采食量线性降低(P<0.05),平均日增重分别下降2.2%、6.6%、15.0%(P<0.05),耗料增重比先降低再升高(P<0.05);随着谷草添加量增加,A至D组的屠宰率未呈显著性差异,但胴体净肉率依次升高;B、C、D组胴体脂肪含量(GR值)较A组分别升高8%、26%、3%;从活羊收益分析,C组的饲料报酬最高;从屠宰收益分析,D组的饲料报酬最高。综上所述,谷草替代全株玉米青贮比例在40%~80%时,对生长性能无显著影响,但可提高胴体净肉率,C组活羊饲料报酬最高,D组获得的屠宰收益最高。     

Human recombinant interleukin-2(125) induced in vitro proliferation of equine, caprine, ovine, canine and feline peripheral blood lymphocytes

Equine, caprine, ovine, canine and feline peripheral blood lymphocytes were evaluated in a short term dose-response study for their in vitro blastogenic responsiveness to human recombinant interleukin-2(125) (HrIL-2(125] alone or in combination with phytohemagglutinin-P, concanavalin-A, and pokeweed mitogen. HrIL-2(125) induced lymphocyte proliferation in all of the animals tested. The magnitude of the proliferative response varied among the species of animal tested. In all cases the proliferative response was dependent on the concentration of HrIL-2(125). HrIL-2(125) at a minimum concentration of 10(2) Cetus Units (CU)/ml produced a significant proliferative response in isolated horse, goat and sheep lymphocytes. In cat and dog lymphocytes, a concentration of 10(3) CU/ml was necessary to induce a significant proliferative response. Maximal lymphocyte proliferation was reached in horses and sheep at a concentration of 10(4) CU/ml of HrIL-2(125). In goats, cats, and dogs a maximum proliferative response was found to be at a concentration equal to or greater than 10(4) CU/ml of HrIL-2. Co-stimulation of lymphocytes with mitogens and submaximal concentrations of HrIL-2(125) (10 CU/ml) induced a synergistic proliferative response which in nearly all cases was significantly greater (P less than 0.05) than the arithmetic sum of the responses induced by the same concentration of the mitogens and HrIL-2(125) alone. The two exceptions were co-stimulation of feline lymphocytes with concanavalin-A and co-stimulation of canine lymphocytes with pokeweed mitogen.     

Characterization and separation of bovine lymphocyte populations

Bovine lymphocyte populations were characterized by surface markers, rosette-forming ability and behaviour towards mitogens. After pre-treatment with neuraminidase 16% of the bovine blood lymphocytes and 14% of the bovine spleen cells formed spontaneous (E) rosettes with sheep erythrocytes. About 20% EAC rosette-forming cells were detected among both cell populations. Protein A receptors were detectable among 8% of the blood lymphocytes and 26% of the spleen cells. Bovine lymphocytes responded to pokeweed mitogen (PWM), phytohemagglutinin (PHA) and concanavalin A (Con A). An enrichment of bovine B and T cells was obtained by E-rosette sedimentation (81–84% B cells) and by filtration through nylon fiber columns (51–65% T cells). The T cells obtained after nylon filtration still responded to the mitogens PHA, Con A and PWM. Enriched B-cell populations responded to bacterial lipopolysaccharide (LPS). After monocyte depletion the mitogenic response of blood lymphocytes was not influenced.     

Selenium, vitamin E and vitamin A status in dairy sheep reared under different feeding systems in Greece

The main purpose of the study was to investigate whether the feeding system applied has any effect on the status of blood selenium (Se) and vitamins A and E in dairy sheep. In total 200 dairy sheep from 10 flocks were used in the study (20 animals per flock). Group A consisted of 100 sheep (five flocks) reared under the intensive feeding system and group B of 100 sheep (five flocks) reared under the semi-intensive feeding system. The 100 sheep of each group consisted of 25 lambs aged 3-6 months, 25 ewes 1-3 years, 25 ewes more than 3 years and 25 non-lactating ewes in late gestation. Another purpose was to evaluate the potential effect of the age and the reproductive stage of the animals on these parameters. To determine the effect of age, 150 of these animals were divided into three subgroups: 50 lambs, 50 non-pregnant lactating ewes aged 1-3 years and 50 non-pregnant lactating ewes aged more than 3 years. For the evaluation of the effect of the reproductive stage the 50 non-lactating ewes in late gestation and the 100 non-pregnant lactating ewes were used. Blood samplings were performed once, between December and January for non-lactating ewes in late gestation and March to May for lambs and lactating ewes. Whole blood Se and vitamin E and A serum concentrations were determined. The main conclusion is that the feeding system significantly affects Se and serum vitamin A concentration, as they were higher in the intensive one. It was secondly concluded that age affects the serum concentrations of vitamin A.     

Isolation of viable canine intestinal lymphocytes

A modification of a previously reported enzymatic technique was used to isolate 60% to 90% pure populations of viable lymphocytes from canine small intestinal mucosa. Mitogenesis assays were then simultaneously performed on these and isolated peripheral blood lymphocytes from the same dogs. A technique to isolate intraepithelial lymphocytes was not successful. Intestinal mucosal lymphocytes were simultaneously purified by 2 different techniques (suspensions B and C), which produced cell populations that responded similarly to phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogens. The peripheral blood lymphocytes demonstrated greater response to PHA and concanavalin A mitogens than did the intestinal mucosal lymphocytes (P less than 0.05). Furthermore, peripheral blood lymphocytes had a significantly higher response to PHA than to pokeweed mitogen (P less than 0.05). The impure preparation of intraepithelial lymphocytes (suspension A) did not show any evidence of reactivity to mitogens. Further studies are needed to determine whether the EDTA or collagenase had any effect upon the intestinal mucosal lymphocyte responsiveness. The present study demonstrated that viable mucosal lymphocytes can be isolated from the canine intestine and that they can maintain their responsiveness to mitogens.     

Characterization of lymphocyte subpopulations in sheep by rosette formation,adherence to nylon wool and mitogen responsiveness

Sheep peripheral blood lymphocytes have been studied using a number of surface markers. Thus 16.6 ± 2.4% (mean ± S.E.) were surface immunoglobulin positive (sIg⁺) by direct immunofluorescence, 35.9 ± 2.1% formed Fc rosettes with bovine red blood cells (RBC) sensitized with rabbit antibody (Fc⁺) and 28.4 ± 2.0% formed rosettes with sheep red blood cells (RBC) in the presence of 4% dextran (DS⁺). The percentage of both Fc⁺ and DS⁺ lymphocytes tended to increase with age of the animals. Demonstration of these markers allowed computation of two further subpopulations: null cells lacking sIg and a receptor for sheep RBC, and Fc·null cells lacking a receptor for Fc and sheep RBC. The former population, which contained a proportion of Fc⁺ lymphocytes comprised 49.8 ± 3.8% of blood lymphocytes and the latter 38.4 ± 3.0%.Separation on nylon wool columns, selective rosette enrichment and depletion on density gradients and stimulation with phytomitogens have shown sIg⁺ and Fc⁺ lymphocytes to be nylon wool adherent and unresponsive to phytohaemagglutinin (PHA) and Concanavalin A (Con A) and DS⁺ lymphocytes to be nylon wool non-adherent and responsive to PHA and Con A. The data also indicates a major overlap of the lymphocyte subpopulations bearing sIg and Fc which are apparently B lymphocytes. Moreover these data support the contention that E-rosette formation with sheep RBC in the presence of dextran is a marker for sheep T cells. The data also indicates that Fc·null cells are T cells, eluting in the non-adherent fraction from nylon wool. It is probable that a proportion of these cells bear a SRBC receptor too weak for present detection methods.     

Flurbiprofen and immunosuppression of Trypanosoma brucei infection in the goat

Goats infected with Trypanosoma brucei and treated with the non-steroidal anti-inflammatory agent flurbiprofen, showed a marked increase in parasitaemia, followed in one of the four goats by death. The in vitro response to mitogens of peripheral blood lymphocytes and separated T- and B-lymphocytes from healthy goats treated with flurbiprofen was normal when compared with non-treated animals. T. brucei-infected goats, not treated with flurbiprofen, showed a marked immunosuppression which was mainly localized in the B-enriched lymphocyte fraction. A combination of T. brucei infection and treatment with flurbiprofen led to even more suppression, because the T-lymphocyte function was also suppressed. It is concluded that flurbiprofen first causes a rise in the parasitaemia and that this high parasitaemia is responsible for the observed immunosuppression.     

Anti-Toxocara spp. antibodies in sheep from southeastern Brazil

The purpose of this study was to evaluate the frequency of anti-Toxocara antibodies in sheep from Presidente Prudente, southeastern Brazil. Serum samples were obtained from 365 sheep of diverse breeds and different ages. Samples were collected at a slaughterhouse and at farms located in Presidente Prudente. Three groups of animal of different ages were evaluated according to age: Group I: between 1 and 6 months old; Group II: between 7 and 10 months old; and Group III: between 11 and 15 months old. An ELISA test was carried out to detect anti-Toxocara antibodies (IgG) using the excretory-secretory antigens of Toxocara canis (TES) larvae. In total, 183 out of 365 animals (50.1%) were positive for anti-Toxocara antibodies. The frequency of antibody detection was directly proportional to the age of the animals (p<0.0001), indicating a relationship between infection and aging. In Group III, there was a higher prevalence in females (p=0.0041). The relevance of these animals to the epidemiology of toxocariasis in pets and human should be considered.     

Effects of age and reproductive stage on certain serum biochemical parameters of chios sheep under greek rearing conditions

The aim of the present study was to determine the normal ranges of the most commonly used serum biochemical parameters of sheep reared under Greek breeding conditions, as well as to test for the effects of the age and reproductive status of the animals on the normal values of these parameters. In total, 200 clinically healthy Chios sheep from 10 farms were used in the experiment. For the determination of the effect of age 150 sheep were assigned in three groups. Group A consisting of 50 lambs aged 2-6 months (mean +/- SD: 4.15 +/- 1.08), group B of 50 non-pregnant ewes into lactation aged 1-3 years (mean +/- SD: 2.12 +/- 0.86) and group C of 50 non-pregnant ewes into lactation aged more than 3 years (mean +/- SD: 5.98 +/- 1.66). For evaluating the effect of reproductive status 50 pregnant ewes in dry period were used, 15-30 days before the expected day of lambing (group D), along with the 100 non-pregnant ewes into lactation of groups B and C (group E). Blood sampling was performed once, in dry ewes from December to January, and in lambs and lactating ewes from March to May. The results showed that of the 14 biochemical parameters determined in serum, six were significantly affected by the age and eight by the reproductive stage of the animals.     

Bovine leukosis virus in sheep,lymphocyte modification and surface-immunoglobulin-bearing cell numbers

Lymphocytes from sheep experimentally infected with bovine leukosis virus (BLV) and from non-infected normal sheep were examined for the presence of surface Ig by an immunofluorescence test. Surface Ig-bearing lymphocytes in blood from BLV-infected sheep increased when lymphocyte counts of blood were elevated in comparison with normal animals. The mitogen stimulation of cultured lymphocytes from BLV-infected sheep and from non-infected normal sheep was determined by measuring ³H-thymidine incorporation. Peripheral blood lymphocytes (PBL) from BLV-infected leukemic sheep with elevated PBL counts responded poorly to phytohemagglutinin M and concanavalin A but responded well to lipopolysaccharide compared with lymphocytes from uninfected animals. In BLV-infected preleukemic sheep with low PBL counts, stimulation indices of mitogen responses of lymphocytes with phytohemagglutinin M, concanavalin A, and pokeweed mitogen were low compared with those of lymphocytes from uninfected animals. The results indicated that B cells were affected by BLV infection in sheep as suggested by the increased number of surface Ig-bearing lymphocytes and that significant alteration of mitogen stimulation of lymphocytes occured in sheep with BLV infection.     

Surface markers for characterisation of bovine blood lymphocyte populations and changes in these from birth to maturity

A sheep erythrocyte (E) rosette technique was developed for use with cattle lymphocytes. This involved the use of 17 per cent Ficoll 400 and preservative-free heparin (84 iu/ml) in the saline-erythrocyte mixture. Using this technique, 83 per cent of peripheral blood lymphocytes in cattle aged between six and 10 years were found to form E rosettes. The remaining cells (17 per cent) were B-cells, so that no cells remained unmarked. Lymphocytes from very young calves contained a population of unmarked or null cells, but these rapidly diminished as the animals matured. A peak of total lymphocytes recovered from blood, as well as E rosette-forming cells, occurred in calves aged four to six months. The non-E rosette-forming cells were mostly B-cells and it was suggested that this was associated with calf weaning. The total number of lymphocytes recovered, as well as E rosette-forming cells, gradually fell with the age of the cattle sampled. Null cells were virtually absent from the blood of cattle six years and older. Bovine T-cells could be further subdivided into Fc mu, Fc gamma and C' receptor-bearing subpopulations on the basis of overlap with R rosette-forming cells. Some further separation of these cells from B-cells was achieved using density gradient centrifugation on Percoll. Separation of E rosette-forming cells with Fc receptors from E rosette-forming cells without Fc receptors was achieved by nylon wool columns, to which the Fc receptor bearing cells were adherent. It was concluded that bovine blood lymphocytes had blood T-lymphocyte populations with markers which may correspond to the 'helper' (Fc mu ) and 'suppressor' (Fc gamma ) populations described for the human.     

Pasteurella haemolytica infections in sheep

Summary Pasteurella haemolytica causes two distinct disease syndromes in sheep. P. haemolytica biotype A causes septicaemia in young lambs and pneumonia in all ages of sheep. Biotype T produces an acute systemic disease affecting principally the upper alimentary tract and lungs in young adult sheep. The bacteriology, epidemiology and clinical and necropsy findings of the two diseases are described and the current situation regarding their experimental reproduction and immunology is reviewed.     

A comparative analysis of the mitogenic response of intestinal intraepithelial lymphocytes in various age groups of turkeys.

Mitogenic responsiveness of intestinal intraepithelial lymphocytes (i-IEL) to concanavalin A (Con A), phytohemagglutinin P (PHA-P), and lipopolysaccharide (LPS) from Salmonella typhimurium were evaluated in various age groups of turkeys by a colorimetric blastogenic microassay. Comparisons were made between mitogenic responses of turkey i-IEL and peripheral blood lymphocytes (PBL). The results from this study demonstrated that i-IEL and PBL of turkeys responded to T-cell mitogens, Con A and PHA-P, in every age group examined. The LPS induced a significant mitogenic response in PBL but not in i-IEL of turkeys. The mitogenic responses of turkey i-IEL and PBL to the three mitogens examined were similar to mitogenic responses observed in an earlier study performed by using chicken i-IEL and PBL. The results indicated a difference in mitogenic response between different age groups. An increase was found in mitogenic response of i-IEL to both T-cell mitogens from 3 days of age to 1 wk of age, whereas mitogenic response of PBL to all three mitogens declined significantly from 1 day of age to 3 days of age. The highest mitogenic response of i-IEL to T-cell mitogens was observed at 1 wk of age. The highest mitogenic response of PBL to both T-cell mitogens was observed at 1 day of age and the highest PBL response to LPS was observed at 16 wk of age. The mitogenic response induced by PHA-P provided less variability between age groups than the mitogenic response induced by Con A.