Immunosuppression in goats inoculated with parainfluenza type 3 virus

The humoral and cellular immune responses of goats experimentally infected with an ovine isolate of parainfluenza type 3 virus (PI-3) were examined. Virus neutralization and enzyme-linked immunosorbent assays were used to determine antibody in the serum and CSF. Lymphocyte stimulation, measured by [3H]thymidine incorporation into peripheral blood leukocytes, was used to determine cellular responses to phytomitogens and virus. There were significant suppression of peripheral blood leukocyte responses to T-cell mitogens early in the course of infection and delayed onset of virus-specific cell-mediated immunity. Delay in antibody formation did not occur. The suppression of mitogen response has been reported with other paramyxovirus infections. The importance of the suppressed cellular immune response for potentiating other infective agents is discussed.     

Suppression of immunologic function and degeneration of lymphoid organs in cyclophosphamide-treated turkeys

Neonatal administration of 8 to 20 mg of cyclophosphamide (CY) in turkey poults resulted in a marked alteration in the morphologic features of all major lymphoid organs. Cyclophosphamide induced severe deficiency in antibody response to multiple injections of Brucella abortus and sheep RBC and in vitro proliferative response of peripheral blood leukocytes to concanavalin A. The morphologic regeneration of thymus and of thymus-dependent areas was marked in all major lymphoid organs by posttreatment day 15. This regeneration preceded functional recovery of the mitogenic response of peripheral blood leukocytes. The regeneration of the bursa and bursa-dependent areas in other lymphoid organs was minimal through posttreatment day 27. Thus, CY may be used effectively in turkeys as an immunosuppressive reagent.     

Effect of fowl adenovirus-1 (IBH isolate) on humoral and cellular immune competency of broiler chicks

Fowl adenovirus-1 (FAV-1), isolated from field outbreaks of inclusion body hepatitis (IBH), was administered orally to 3-week-old disease-free broiler chicks. Humoral immune competency was evaluated by determining the antibody response of infected chicks to sheep red blood cells (SRBC) and Brucella abortus. FAV-1 infection significantly decreased the antibody response of chicks to B. abortus (T-cell-independent antigen) by decreasing IgM responses, however, the decreased antibody response to SRBC (T-cell-dependent antigen) was statistically non-significant. Bursal index was also found lowered in infected chicks as compared to the control chicks. A significant decrease was seen in blastogenesis response of peripheral blood lymphocytes to phytohaemagglutinin (PHA-P) in FAV-1-infected chicks on 2 and 3 weeks post-infection (WPI). These results indicated that FAV-1 affects humoral as well as cellular immune competency of infected chicks.     

Specific lymphocyte stimulation in cattle naturally infected with strains of Brucella abortus and cattle vaccinated with Brucella abortus strain 19.

Cell-mediated immune responses in cattle naturally infected with strains of Brucella abortus and in cattle vaccinated with B abortus strain 19 during calfhood were studied by an in vitro lymphocyte-stimulation procedure. Lymphocytes were prepared from peripheral bovine blood by the Ficoll-diatrizoate technique, suspended in RPMI-1640 medium (1.5 X 10(6) lymphocytes/ml), cultured with B abortus-soluble antigen or phytohemagglutinin, and incubated for 6 days. Sixteen hours prior to termination of incubation, cultures were labeled with 1 muCi of [3H]thymidine (3HdT) and, after harvesting, assayed for 3HdT incorporation into DNA by liquid scintillation spectrometry. Lymphocytes from cattle with bacteriologically confirmed isolation of B abortus underwent a significantly higher lymphocyte stimulation with B abortus-soluble antigen than did cattle vaccinated with B abortus strain 19 during calfhood (P less than 0.005). Standard seroagglutination tests were conducted simultaneously with lymphocyte-stimulation tests, but there was no apparent correlation between levels of humoral antibodies and the cell-mediated immune responses as measured by in vitro specific lymphocyte stimulation.     

Immunopotentiation of cattle vaccinated with a soluble Brucella abortus antigen with low LPS content: an analysis of cellular and humoral immune responses.

The adjuvant effects of dimethyl dioctadecyl ammonium bromide (DDA) alone or in combination with trehalose dimycolate (TDM) or muramyl dipeptide (MDP) on bovine humoral and cellular responses to a soluble protein extract of gamma irradiated Brucella abortus strain 19 (SPEBA) were investigated. Thirty-five beef steers were randomly allotted to nine groups. Three of these groups received SPEBA (2 mg protein per dose) subcutaneously in combination with adjuvants, one group received the reduced dose of B. abortus strain 19 (S19), and one group received SPEBA alone. Controls included groups receiving adjuvant preparations only or no vaccine. Immune responses to the various immunizations were assessed sequentially for 56 days using various in vitro and in vivo assays. The humoral response to B. abortus was measured using standard serologic tests, an enzyme-linked immunosorbent assay, and a quantitative fluorometric immunoassay. The cell-mediated immune (CMI) response was measured by antigen-specific lymphoproliferation (LP), interleukin 2 (IL 2) production, and soluble suppressor factor release. Skin testing at day 35 for delayed-type hypersensitivity (DTH) to SPEBA was also performed. Minimal humoral responses were induced with SPEBA alone. The highest and most sustained serum antibody responses to B. abortus antigens were elicited by the S19 vaccine. A combination of SPEBA with DDA + TDM induced higher antibody levels than SPEBA with DDA or SPEBA with DDA + MDP. Responses to DTH among the groups receiving SPEBA were most notable in the SPEBA with DDA + TDM groups. Increased IL 2 production was greatest in the S19 and SPEBA with DDA + TDM vaccinates. The results indicated that a combination of DDA + TDM best potentiated immune responses to a soluble B. abortus antigen preparation and may be useful as adjuvants for future vaccines.     

Experimentally induced Cooperia oncophora infection in calves: lymphocyte blastogenic and delayed hypersensitivity responses

Lymphocytic responses in peripheral blood and visceral lymph to Cooperia oncophora antigen and skin tests were determined in 35 Holstein male calves that were inoculated orally with single or multiple doses of C oncophora infective larvae. Several calves were vaccinated or given immune serum before larvae were inoculated. Antigen-specific in vitro blastogenesis of blood and lymph lymphocytes and delayed-type hypersensitivity reactions were observed in several inoculated, vaccinated, and/or passively immunized calves. Most calves that had delayed skin reactions also had in vitro lymphocyte responses to C oncophora antigen. The lymphocyte and skin responses were inconsistent and variable in time of onset--the earliest lymphocyte response occurring 7 days after calves were inoculated. A cellular immune response was induced by both dermal vaccination and oral inoculation; however, passive immunization by IV administration of immune serum simultaneously with inoculation did not have an apparent effect on the cellular response, as measured by the lymphocyte blastogenesis test or dermal testing. Although cellular immune responses were observed in several calves infected with C oncophora, there was no apparent relationship between the specific responses and number of nematodes establishing infection in calves after either single- or multiple-dose oral inoculations.     

A comparison between the effect of an avian reovirus and infectious bursal disease virus on selected aspects of the immune system of the chicken

Reovirus 81-176 was inoculated subcutaneously into day-old specific-pathogen-free leghorns and evaluated for its effects on the immune system over a 3-week period. Structural criteria included organ weights of the bursa of Fabricius (BF) and spleen (SP), scoring of histological lesions in the BF, SP, and thymus, and hematological analyses of the circulating leukocytes. Alterations in the functional capacity of the immune system were measured using the graft-versus-host reaction, the response of peripheral blood lymphocytes (PBLs) to mitogens, the ability of circulating monocytes to phagocytize latex beads, and the serological responses to Newcastle disease virus, sheep red blood cells, and Brucella abortus antigens. For comparison, infectious bursal disease virus (IBDV) was similarly evaluated by most of the same tests. Structurally, reovirus 81-176 altered BF and SP organ weights, the total numbers of white blood cells in circulation, and the degree of follicular atrophy in the BF. Functionally, reovirus inoculation reduced both the response of PBLs to the phytohemagglutinin-P stimulation and monocyte uptake of latex beads. According to the protocols used here, no significant alteration in B-cell function could be detected in reovirus-infected chicks. With the exception of leukocyte hematology, IBDV-infected chicks had significantly altered responses in all tests used. By way of comparison, the effects of IBDV were more persistent and pronounced than were those seen with reovirus. The graft-versus-host reaction indicated an elevated and/or uninhibited response of T-cells in the blood of IBDV-infected chicks.     

Cell titration assay for measuring blastogenesis of bovine lymphocytes

The blastogenic response of bovine peripheral blood lymphocytes to phytohemagglutinin (PHA) and to microbial antigens was measured using a lymphocyte titration assay. Culture conditions, including lymphocyte concentrations, incubation periods and medium formulation, were established which produced linear or nearly linear responses over a range of cell concentrations. These conditions were established by testing lymphocytes from unimmunized cattle and from heifers infected with Brucella abortus with PHA and a B. abortus extract. Four cell concentrations in 2-fold increments were selected for measuring responses to PHA (3.125 X 10(3) to 2.5 X 10(4) cells/well) and to antigens (5.0 X 10(4) to 4.0 X 10(5) cells/well). The strength of response varied among animals and also over time for individual animals, but the titration assay allowed exponential proliferation to be distinguished from decline, which may have been due to overcrowding of microtiter wells, exhaustion of nutrients or induction of regulatory events. This assay provided a more reliable and discriminating method of evaluating lymphocyte proliferation responses than that achieved by single point assays. The displacement of the titration curves could be used to estimate the relative frequency of lymphocytes responding to antigens or mitogens.     

Immunologic and pathologic responses of cows to naturally occurring Mycoplasma bovis mastitis

Systemic humoral and cell-mediated immune responses of four Holstein cows with natural Mycoplasma bovis mastitis were evaluated to determine whether a relationship exists between systemic cellular and humoral responses and the pathogenesis and resolution of infection. In vitro lymphocyte activation tests of peripheral blood lymphocytes and in vivo skin tests with M. bovis antigens provided evidence that cell-mediated immune responses against M. bovis may be involved in successful resolution or containment of infection. In several observation it appeared that viable M. bovis and their aqueous extracts are suppressive to cell-mediated responses.Humoral responses were determined by the serum indirect hemagglutination (IHA) test and the growth inhibition test. The IHA titers after approximately 2 weeks of infection were elevated; however, 75–87% of the IHA activity was in the IgM antibody class.The cell-mediated immune responses may be necessary for resolution of mycoplasmal mastitis both directly and via their helper cell function on antibody production. However, it appears that immune injury to mammary tissue results from the immunologic response to infective mycoplasma. Presence of locally secreted antibody and locally active immune cells may provide a better indication of those animals in the process of resolving the infection than was observed using systemic indicators of immune responsiveness such as indirect hemagglutination or growth inhibition tests.     

Characterization of peripheral blood and pulmonary leukocyte function in healthy foals

Studies in infants and foals indicate an age-dependent maturation of peripheral lymphocyte subsets. The age-dependent relationship for maturation of cellular immune responses, such as phagocytosis and lymphocyte responses of the peripheral and pulmonary-derived leukocytes, has not been characterized in foals. Lymphocyte subpopulations, mitogen stimulation response of lymphocytes, lymphokine-activated killing cell activity, phagocytosis and oxidative burst activity, and serum immunoglobulin (Ig) classes G and M concentrations were determined in developing foals. This study illustrates age-dependent changes in immunoglobulin class concentrations, lymphocyte subsets, and EqMHC Class II expression in cells of the peripheral blood and lungs of developing neonatal-to-weanling foals. The increase in peripheral blood and BAL B-lymphocytes and serum immunoglobulins in developing foals suggests expansion of immune cell populations during a time in which environmental pathogen exposure is great. General immune function, mitogenic responses, LAK cell activity, opsonized phagocytosis, and oxidative burst activity of newborns was similar to the adult horse. Total immune-cell numbers, rather than function, seemed to be the limiting factor in the development of the equine neonatal immune system. There was an age-related percent increase in the appearance of pulmonary lymphocytes, but a percent decrease in macrophages. Although development of the respiratory immune system follows changes in the peripheral blood, cellular expansion, activation, and migration may occur at a slower pace, making the respiratory environment susceptible to pathogens prior to optimal immune system maturity.     

Effects of the lipopolysaccharide-protein complex and crude capsular antigens of Pasteurella multocida serotype A on antibody responses and delayed type hypersensitivity responses in the chicken.

The effects of the lipopolysaccharide-protein complex (LPS) and crude capsular antigen (CCA) prepared from Pasteurella multocida serotype A isolated from a duck in the Philippines, on antibody responses to sheep red blood cells (SRBC) and Brucella abortus (BA) and delayed type hypersensitivity (DTH) responses to bovine serum albumin (BSA) in the chickens were studied. Chickens injected subcutaneously with LPS and CCA at 1 and 2 weeks of age and immunized intravenously with the mixed antigens of SRBC and BA, at 3 and 4 weeks of age showed significantly increased antibody responses against both SRBC and BA, when evaluated at 7 days after each immunization. In addition, these chickens sensitized intramuscularly with the emulsion of BSA in complete Freund's adjuvant at 5 weeks of age, and then injected into the wattle with BSA at 7 weeks of age also showed significantly increased DTH responses against BSA, when evaluated at 24 and 48 hr after challenge. These results indicate that LPS and CCA of P. multocida serotype A have a property enhancing humoral and cell-mediated immune responses.     

Effects of induced moulting on immune responses of hens.

1. The potential for induced moult to be a stressor and therefore alter the immune response in hens was examined. Spent hens from White Leghorn and White Rock layer flocks were induced into a moult by withdrawal of food and the effects on the humoral and cellular immune responses of these birds were examined. 2. Lymphocyte numbers were lower in moulted birds compared with nonmoulted controls. 3. Antibody responses to sheep red blood cells or Brucella abortus antigen were largely unaffected. 4. The delayed type hypersensitivity response to the skin sensitiser dinitrofluorobenzene (DNFB) was depressed during the period of food withdrawal but recovered when feeding resumed. 5. Induced moulting probably has a negative effect on the cellular component of the immune system of the moulted birds.     

Chickens bursectomized with mibolerone have Ig-positive cells which lack bursal cell specific antigens

The bursa anlage failed to develop in chicken embryos injected with 5 micrograms mibolerone on the 5th day of embryonation. Humoral immune responses in treated birds were studied by challenging them with sheep red blood cells (SRBC) and killed Brucella abortus (B. abortus) at 4, 5, 6 and 7 weeks of age. Control birds responded with IgM and IgG titers to SRBC and B. abortus, whereas mibolerone-treated birds completely failed to respond to B. abortus and their responses to SRBC consisted of only IgM agglutinins. Mibolerone-treated birds lacked natural agglutinins to rabbit red blood cells. The total concentration of plasma IgG, measured by radial immunodiffusion, was diminished whereas the IgM level was not influenced by the mibolerone treatment. Mibolerone-treated birds lacked bursal cell specific antigens in the peripheral blood leucocytes (PBL) but they still had Ig-positive fluorescing cells which were fewer in number than those of controls. Splenomegaly resulting from graft vs. host reactions induced in chick embryos by PBL from mibolerone-treated birds was similar to that in control birds, indicating normal alloreactive T cells. These results suggest that IgM responses observed in mibolerone-treated birds are produced by cells from an extrabursal site, and that mibolerone can be used effectively to chemically bursectomize chickens.     

Primary and anamnestic responses of bovine bronchoalveolar and peripheral blood lymphocyte subsets to aerosolized Pasteurella haemolytica A1

Site-specific responses of bronchoalveolar and peripheral blood lymphocyte subsets were compared during primary and anamnestic immune responses against live Pasteurella haemolytica A1 (Ph1). Eight 1-year old calves were sequentially exposed intrabronchially with aerosolized Ph1 on days 0, 14, and 21, and two calves were sham exposed. Bronchoalveolar and peripheral blood lymphocytes were analyzed before each Ph1 exposure, and on days 3 and 7 post exposure using single and two-color flow cytometry to identify CD2+, CD4+, CD8+, CD21+, CD45R+, CD25+ and gammadelta lymphocyte subsets. Significant differences (p < 0.05) in bronchoalveolar and peripheral blood lymphocyte subsets were observed before Ph1 exposure. Subsequent aerosol exposures, resulted in significant (p < 0.05) changes in bronchoalveolar lymphocyte subsets and the CD4:CD8 bronchoalveolar lymphocyte ratio, but concomitant changes were not observed in peripheral blood lymphocytes. Expression of CD2, CD4 and CD8 lymphocyte differentiation antigens was consistently lower and more heterogeneous on bronchoalveolar lymphocytes. Differential analysis of bronchoalveolar leukocytes revealed a significant increase in bronchoalveolar lymphocytes and neutrophils during anamnestic responses.     

Effects of standard and variant strains of infectious bursal disease virus on infections of chickens

T-cell-mediated and humoral immune responses were measured in chickens infected with standard and variant strains of infectious bursal disease virus. One-day-old and 3-week-old chickens were infected with these viruses and then given sheep RBC, killed Brucella abortus strain 19, and Newcastle disease virus. Appropriate serologic tests were used to monitor the primary and secondary responses to the antigens. Lymphoblast transformation assays were performed weekly. The response to the infectious bursal disease virus was determined by virus neutralization tests, microscopic examination of bursas, and bursal to body weight ratios. One-day-old chickens had T-cell-mediated and humoral immune suppression with both strains of virus, compared with controls. The lymphoblast transformation responses indicated that the variant strain was significantly (P less than 0.05) more suppressive than the standard strain. Three-week-old chickens had humoral immune suppression with the standard strain, but not with the variant strain. The lymphoblast transformation response was transiently suppressed at this age by the variant strain only. During the first week of infection, 1-day-old and 3-week-old chickens had lower neutralizing antibody titers to the variant strain than to the standard strain.     

Interactions of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) with immune responses of rainbow trout

Chlorinated dioxins, as typified by the most potent isomer, TCDD, are immunosuppressive in mammalian species and can enhance the susceptibility to a number of diseases. In recent years chlorinated dioxins have been detected in fish in many freshwater and marine habitats. Thus far, the effects of these chemicals on the immune responses of fish have not been examined. We studied the influence of TCDD on the defense mechanisms of rainbow trout. Yearling trout were injected intraperitoneally with the vehicle, 0.1, 1.0 or 10 micrograms/kg of TCDD. Interactions with the humoral immune response to sheep red blood cells (SRBC) were assessed by the Jerne plaque assay using head kidney and spleen leukocytes. Serum antibody was measured by complement-mediated lysis of SRBC in a chromium release assay. Effects of TCDD on the cellular immune responses were evaluated by the response of thymic and splenic lymphocytes to Con A and PWM. In addition, the phagocytic activity of peritoneal macrophages was examined in vitro. Trout which received 0.1 or 1.0 micrograms/kg TCDD remained clinically normal, and defense mechanisms were unaltered in these fish. Trout which received 10 micrograms/kg of TCDD became hypophagic and exhibited fin necrosis, ascites and suppression of hematopoiesis. In this treatment group, Con A-induced blastogenesis of thymic and splenic lymphocytes was not significantly changed, however, suppression of the PWM-induced response of splenic lymphocytes occurred. No statistically significant alterations occurred in humoral immune responses, and phagocytic activity of peritoneal macrophages was not decreased. The dose-response curve for various biologic effects of TCDD in the rainbow trout appears different from that in sensitive mouse strains. The 30-day, single-dose, parenteral LD50 for TCDD in the C57BL mouse is 100 micrograms/kg, and TCDD suppresses both cell-mediated and humoral immune responses at 1-2 micrograms/kg in this mouse strain. In the rainbow trout, however, immunosuppression was evident only at doses of TCDD approaching the 80-day, single-dose, parenteral LD50 of 20 micrograms/kg.     

Kinetics and type of immune response following intranasal and subcutaneous immunisation of calves

Protection of animals against respiratory infections has long been known to depend on respiratory mucosal immunity. However, few studies have been reported on the immune response following intranasal (i.n.) immunisation with non-living, soluble antigens. This study determined the kinetics of the humoral and cellular immune responses in calves after i.n. immunisation with Limulus haemocyanin (LH) with cholera toxin adjuvant, or subcutaneous (s.c.) immunisation with LH in incomplete Freund's adjuvant. A proliferative response of peripheral blood mononuclear cells cultured in vitro with LH was observed in animals immunised 7-10 days after i.n. and s.c. immunisations with no significant differences between the two immunised groups. LH -specific antibody was present in the serum of animals immunised s.c. (IgM, IgG1 and IgG2) and i.n. (IgA). Although significant IgA responses were observed, i.n. immunisations in cattle with soluble protein antigens and cholera toxin as an adjuvant did not induce a strong systemic immune response.     

猪传染性胸膜肺炎与猪肺疫二联亚单位疫苗的免疫效果评价

为了评价猪传染性胸膜肺炎与猪肺疫二联亚单位疫苗(由多杀性巴氏杆菌外膜蛋白H(OmpH)质粒导入胸膜肺炎放线杆菌(APP)菌影制备)的免疫效果,于某规模化猪场选取30头无上述病原菌和抗体的4周龄(w)仔猪,随机分为安全评估组和试验组进行免疫,试验组包括APP组、OmpH组、APP+OmpH联苗组,分别于4、6 w肌肉注射2 mL/头相应疫苗,采取4、6、9 w外周血,用流式细胞术、ELISA、血常规、血生化试验分析疫苗免疫后,相关免疫因子、免疫细胞及免疫球蛋白的变化。结果显示:APP+OmpH组外周血中CD3⁺、CD8⁺细胞增加数量比APP、OmpH组显著增多(P<0.05);血清抗体结果显示,APP+OmpH组结果优于APP和OmpH组;APP+OmpH组的外周血白细胞数、淋巴细胞数、中性粒细胞数、单核细胞数在二免后增多,白蛋白、球蛋白亦明显增加,且APP+OmpH组增加数量多于APP和OmpH组。结论:APP+OmpH组能更好地刺激机体细胞免疫和体液免疫反应,进而发挥免疫保护效果。     

Evidence for immunosuppression associated with Jembrana disease virus infection of cattle.

Jembrana disease virus (JDV) is a newly recognised bovine lentivirus causing an acute disease syndrome in Bali cattle (Bos javanicus) in Indonesia. We evaluated the effect of JDV infection on the antibody response to chicken ovalbumin (cOVA) and Brucella abortus Strain 19 in Bali cattle. In infected cattle the IgG and IgM response to cOVA was suppressed and delayed and the IgG response to B. abortus Strain 19 was delayed. The results indicate that the humoral immune response is suppressed and delayed in JDV infected cattle.     

Correlated responses of respiratory disease and immune capacity traits of Landrace pigs selected for Mycoplasmal pneumonia of swine (MPS) lesion

Five generations of Landrace pigs selected for average daily gain, backfat thickness, Mycoplasmal pneumonia of swine (MPS) lesion score, and plasma cortisol levels, was executed to decrease the MPS lesion score. Genetic parameters and correlated genetic responses for respiratory disease and peripheral blood immune traits were estimated in 1395 Landrace pigs. We estimated the negative genetic correlation of MPS lesion score with phagocytic activity (PA) at 7 weeks of age (‐0.67). The breeding values of PA at 7 weeks of age and 105 kg body weight and the correlated selection response of the ratio of granular leukocytes to lymphocytes at 105 kg body weight were significantly increased, and sheep red blood cell‐specific antibody production (AP) was significantly decreased in a selection‐dependent manner. Increasing of natural immunological indicators (e.g. PA) and decreasing of humoral immunological indicator (e.g. AP) were observed due to genetically decreasing MPS lesion score.