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1.
Corticosteroids given in vivo altered the response of lymphocytes in the peripheral blood of calves. Lymphocytes were cultured and stimulated in vitro with phytohemagglutinin (PHA). After an initial suppression of lymphocyte responses to PHA, there was a rapid return to normal. It is concluded that, in calves, short-term, high-dose immunosuppressive therapy with corticosteroids produces a population of lymphocytes resistant to corticosteroids, possibly by destruction of corticosteroid-sensitive lymphocytes.  相似文献   

2.
The in vivo and in vitro effects of Trichinella spiralis excretory-secretory (ES) antigens on porcine peripheral blood lymphocyte (PBL) responses induced with mitogens (phytohemagglutinin, PHA; concanavalin A, Con A; pokeweed mitogen, PWM) or unrelated antigen (Protein A) were studied to determine whether ES antigens depress lymphocyte responses in experimental swine trichinosis, and/or if this response was manifested after lymphocytes from infected pigs had been pretreated with ES antigens. Additionally, the range of inhibition of lymphocyte responses was tested in parasite-free pigs using different doses of ES antigens and compared with the responsiveness of control cultures from the same animals. The responses of lymphocytes from pigs inoculated with 4 x 10(3) muscle larvae (ML) were strongly depressed (P < 0.05) at post-inoculation days (PID) 7 (after stimulation with PHA), 14, 35 (Con A or PWM), and 49 (PWM). At PID 56 and 63 the lymphocytes from T. spiralis-infected pigs responded better (P < 0.05) to all three mitogens than those from non-infected controls. After 7 weeks post-inoculation, PBL which were pretreated with 10 or 250 micrograms ml-1 of ES antigens showed significantly weaker (P < 0.05, P < 0.001) responses to PWM or PHA, respectively, than those from non-infected animals. The responsiveness of lymphocytes from both groups of pigs to Protein A was not affected by the pretreatment with ES antigens in vitro. The responses of lymphocytes from the parasite-free pigs induced by PHA, PWM or Protein A were strongly depressed (P < 0.01) after in vitro pretreatment regardless of the dose of ES antigens (5, 10, 15, or 20 micrograms ml-1) applied.  相似文献   

3.
The influence of allogeneic IgG on in vitro reactivity of peripheral blood lymphocytes (PBL) of neonatal colostrum-deprived piglets as well as of suckling and weaned piglets was studied. PBL were preincubated with purified allogeneic IgG for 24 h before their ability to respond to PHA, Con A or PWM was tested. PBL of precolostral piglets pretreated with allogeneic IgG exhibited higher response to PHA (P less than 0.01) than untreated control cells. An increased response of PBL treated with IgG was also observed in suckling piglets as compared to their respective control cells (P less than 0.01). Responsiveness of PBL treated with IgG to PWM was suppressed. No differences in response to Con A regardless of the sources of lymphocytes was observed as compared to IgG untreated controls. The results suggest that pretreatment of lymphocytes of piglets with allogeneic IgG modulates their reactivity to mitogens, suppressing the response to PWM and stimulating the response to PHA, respectively.  相似文献   

4.
Before dogs with lung tumors were treated by adoptive immunotherapy, the ability of canine blood lymphocytes (PBL) from the peripheral circulation to differentiate in vitro in the presence of human recombinant interleukin-2 (rIL-2) and become tumoricidal was investigated. The PBL from healthy dogs (n = 6) and dogs with lung tumors (n = 5) were grown in culture medium alone, in the presence of rIL-2 to generate lymphokine-activated killer (LAK) cells, or with phytohemagglutinin (PHA) and rIL-2 to generate autologous-stimulated lymphocytes (ASL). After 4 days, cytotoxicity by the ASL, LAK, and PBL was determined in a 4-hour 51chromium-release assay. Target cells in the assay were short-term cultured enzyme digests of autologous (self), allogeneic (genetically different) primary tumors, and Raji, the xenogeneic human lymphoma cell line. The PBL cultured without rIL-2 were not cytotoxic against any tumor. However, when a dog's PBL were activated in vitro, they killed the dog's own tumor, ASL more effectively than LAK cells. Pulmonary adenocarcinomas and an osteosarcoma metastasis to lung were among the autologous tumors assayed. Against an allogeneic canine osteosarcoma, ASL generated from healthy dogs were significantly more cytolytic than LAK from healthy dogs, or than ASL generated from tumor-bearing dogs. Cytotoxicity was greater against allogeneic tumor than against Raji. Lectin-dependent cellular cytotoxicity, tested by including PHA in the assay medium with lymphocytes and Raji cells, by ASL and LAK was greater than cytotoxicity of Raji without PHA. Because ASL were more cytolytic than LAK against all targets in vitro, they may be more beneficial than LAK for immunotherapy of canine tumors.  相似文献   

5.
Peripheral blood lymphocytes (PBL) from normal and bovine leukemia virus (BLV)-infected cattle were prepared by density gradient technique and incubated with and without phytohaemagglutinin (PHA) and pokeweed mitogen (PWM). RNA synthesis was determined at different periods of incubation by 3H-uridine incorporation. PBL from BLV-infected cows with persistent lymphocytosis (PL) showed the highest spontaneous RNA synthesis. PBL from BLV-infected cows with normal lymphocyte counts synthesized more RNA than cells from normal animals. Decreased mitogen responses were observed in PBL from infected cows with PL in comparison to normal and BLV-infected cattle without PL. PHA and PWM did not show significant differences in their degree of stimulation of RNA synthesis.  相似文献   

6.
In vivo inoculation of three-month-old calves with sodium diethyldithiocarbamate (DTC), killed Corynebacterium parvum or mycobacterium cell wall extract (MCWE) resulted in an enhancement of in vitro peripheral blood lymphocyte blastogenic responses to mitogens phytohemagglutinin (PHA) and Concanavalin A (Con A) in the first three days after treatment. In a separate experiment, blood lymphocytes isolated from a healthy nontreated calf were incubated in vitro in presence of each of the same immunostimulating agents and tested for their blastogenic responses to PHA and Con A. The results showed that all immunostimulants, excepting DTC, enhanced the in vitro blastogenic responses of lymphocytes to PHA and Con A. Finally, addition of MCWE to cultures of blood lymphocytes isolated from calves vaccinated intramuscularly with bovine rotavirus and adjuvant resulted in an enhancement of the in vitro lymphocyte transformation to rotavirus. Our study demonstrated that DTC, killed Corynebacterium parvum and mycobacterium cell wall extract were able to enhance bovine T cell proliferation in vitro.  相似文献   

7.
The distributions of phytohemagglutinin-P (PHA) and concanavalin A (ConA) binding sites were investigated for equine, bovine and canine peripheral blood lymphocytes (PBL). Non-B lymphocytes were collected from each PBL using a fluorescence-activated cell sorter (FACS), and the numbers of PHA and ConA binding sites on their surfaces were counted. Most PHA binding sites on PBL of the three species were shown on the surfaces of non-B lymphocytes. On the other hand, the ConA binding sites on equine and canine PBL existed mainly on the surfaces of non-B lymphocytes, but B lymphocytes of these two species had many ConA binding sites. These results were confirmed by the results of two-parameter fluorescence analysis using FACS. It is, therefore, concluded that the different optimum concentrations of PHA and ConA in PBL blastogenic responses of each animal depended on the different distributions of their binding sites.  相似文献   

8.
The phenomenon of the unusually high spontaneous suppressive activity of cells in peripheral blood of dogs was analysed. The m/c (mitomycin C)-treated population of peripheral blood leucocytes (PBL) contained cells able to reduce the responsiveness of autologous cells by 48 +/- 15% (P less than 0.01) and their activity was not indomethacin dependent. Thoracic duct lymphocytes (TDL) did not reduce the response of PBL to PHA, neither did cell crowding. The supernatants from 24-h cultures of m/c-treated PBL did not affect the response to PHA, and parallelly precultured cells inhibited the proliferation of PBL to a lesser degree (24 +/- 9%) than the fresh cells (50 +/- 16%, P less than 0.05). Addition of m/c-treated polymorphonuclear cells at PMN to PBL ratios of 1:4 and 1:1 progressively inhibited PBL reactivity to PHA, from 29.5 +/- 3.5% to 68.5 +/- 9%, respectively, and the supernatants from 24-h cultures of PMN reduced the proliferation by 48 +/- 2.8%. The neutrophil-derived inhibitory factor(s) was non-cytotoxic and reduced the formation of blasts to 61.5 +/- 3.5% of the control values. These results indicate that dog PBL from Lymphoprep gradient contain a population of non-recirculating, short-lived, spontaneously suppressive cells, mainly PMN, which modulate T cell reactivity in vitro, suggesting that neutrophils may be able to exert a regulatory effect in vivo.  相似文献   

9.
The effects of prednisolone sodium succinate on the responses of porcine lymphocytes to phytohemagglutinin (PHA) and pokeweed mitogen (PWM) were investigated. Sensitivity of peripheral blood lymphocytes (PBL) to the synthetic glucocorticoid, prednisolone, was related to age of the lymphocyte donor. The greatest sensitivity was found in PBL from animals less than one week old; PBL from animals between 2 to 4 months retained some glucocorticoid sensitive cells; whereas, PBL from animals older than 6 months were exceptionally resistant to steroid. Similar age-associated sensitivities were found for lymphocytes from lymph node, spleen and thymus. Significant differential sensitivities among the various lymphoid organs were found with the thymic lymphocyte possessing the greatest sensitivity to steroid and the PBL lymph node and splenic lymphocytes possessing the highest resistance to the suppressive effects of steroid. The age related differences in sensitivity to steroid did not appear to be caused by differences in the number of steroid receptors because lymphocytes from susceptible and resistant animals had similar numbers of receptors. The results suggest that the age related sensitivity may be associated with a higher percentage of sensitive thymic-derived lymphocyte in the PBL, lymph node and spleen of the younger animals. Results of this study also suggest that the adult pig (6 months) should be classified as a steroid resistant species.  相似文献   

10.
Intradermal injection of a Culicoides antigen extract (CAgX) induces T lymphocyte and eosinophil accumulation in the skin of horses with sweet itch. Blood mononuclear (BMN) cells from normal ponies proliferate when stimulated by mitogen (phytohaemagglutinin, PHA) or antigen (tetanus toxoid, TT) and, as shown here, release soluble factor(s) that induce eosinophil adherence. CAgX also caused concentration dependent proliferation of BMN cells from sweet itch and normal ponies [stimulation index: 29 (13) and 17 (7) for BMN cells from sweet itch and normal ponies, respectively during the active phase of disease; 4 microg protein ml(-1)CAgX; 168 h]. A heat labile factor(s) which caused eosinophil adherence was also released [sweet itch ponies: 6.0 (1.6) per cent adherence versus 1.3 (0.4) per cent; normal ponies: 6.6 (0.5) per cent adherence versus 0.9 (0.1) per cent for supernatants from CAgX (4 microg protein ml(-1); 48 hours) stimulated versus unstimulated BMN cells, respectively]. These results suggest that soluble proteins released from T lymphocytes could affect eosinophil function in the lesional skin of sweet itch horses.  相似文献   

11.
Peripheral blood lymphocytes (PBL) from non-vaccinated dogs and from dogs either vaccinated intramuscularly (IM) or subcutaneously (SC) with an inactivated rabies virus vaccine (Rabguard-TC, Norden Laboratories, Lincoln, NE) or intramuscularly with an attenuated rabies virus vaccine (Endurall-R, Norden Laboratories, Lincoln, NE) were exposed in vitro to rabies virus. Blastogenesis of PBL was measured by incorporation of 3H-thymidine into the DNA of proliferating cells in the presence of a suboptimal concentration of phytohemagglutinin (PHA). Following the first vaccination, there was no difference in the blastogenic response of lymphocytes from dogs vaccinated IM with either the inactivated or attenuated rabies virus vaccines. The inactivated rabies vaccine stimulated as great or greater blastogenic response when it was given SC. The PBL from non-vaccinated control dogs were not stimulated by rabies virus. Dogs vaccinated with the inactivated vaccine developed a lymphocyte blastogenic response to rabies virus following challenge with virulent street rabies virus. Nonvaccinated control dogs did not develop a lymphocyte blastogenic response to rabies virus following challenge with virulent street rabies virus.  相似文献   

12.
In the present study peripheral blod mononuclear cells (MNC) obtained from normal uninfected lambs were used to study the possible effects of bovine respiratory syncytial virus (BRSV) on lymphocyte responses to the mitogens, phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) in vitro. Live BRSV had a depressive effect on the proliferative responses of normal MNC to PHA, Con A and PWM. Inactivated BRSV and a commercial preparation of prostaglandin E2 were also found to depress the proliferative responses of normal ovine MNC to PHA but recombinant tumour necrosis factor-alpha (TNF-alpha) had no such effect. Serum samples obtained from BRSV-infected lambs contained substances inhibitory to PHA-driven lymphocyte blastogenesis. Memory blastogenic responses to border disease virus (BDV) of lymyphocytes obtained from lambs previously primed with BDV were significantly reduced when lymphocytes were exposed to infectious BRSV.  相似文献   

13.
OBJECTIVE: To determine if there is a difference in in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. To determine the effects of a corticosteroid and monokine on in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. STUDY DESIGN: Growth of fibroblasts from tissues harvested from the trunk and limb were compared from horse and pony samples grown in control media and control media with triamcinolone or monokine added. ANIMALS OR SAMPLE POPULATION: Dermal and subcutaneous tissue from 22 horses and 17 ponies of various ages and breeds. METHODS: Fibroblast growth was assessed by tritiated thymidine uptake using standard cell culture techniques. The effect of a monokine or triamcinolone plus control media were compared with control media for fibroblast growth. RESULTS: Fibroblast growth from tissues isolated from the horse limb was significantly less than growth from the horse trunk and the limb and trunk of ponies. Monokine was more effective than triamcinolone in suppressing fibroblast growth from tissues isolated from the trunk and limb in both horses and ponies. CONCLUSIONS: There are growth differences in fibroblasts isolated from the limb of horses compared with those isolated from the trunk and from the limb and trunk of ponies. CLINICAL RELEVANCE: The difference in fibroblast growth from tissues isolated from the trunk and limb of horses and ponies may provide evidence for the difference reported in the healing characteristics of limb wounds in horses and ponies. Influencing fibroblast growth may provide a key to controlling the development of exuberant granulation tissue in horses and ponies.  相似文献   

14.
Peripheral blood lymphocytes (PBL) prepared by centrifugation of heparinized sheep or goat jugular venous blood on Ficoll-Triosil were shown to incorporate methyl-[H3]-thymidine ([H3]-Tdr) in vitro in response to lymphocyte mitogens.Optimal conditions for transformation included the culture of 2.5 × 105 viable cells per round bottomed culture well in 250μl medium RPMI-1640 supplemented with fetal calf serum (FCS) at 10% for goat or 15% for sheep lymphocytes. Optimum incorporation of [H3]-Tdr by sheep PBL was recorded after 3–5 days and was achieved in response to 100μg/ml phytohaemagglutinin (PHA), 20μl/ml pokeweed mitogen (PWM), 10μg/ml Concanavalin-A (Con-A) and 50μg/ml bacterial lipopolysaccharide (LPS). For goat PBL the optimum mitogen concentrations were 50μg/ml PHA, 20μl/ml PWM, 5μg/ml Con-A and 50μg/ml LPS. Optimum PHA concentrations were influenced by the level of FCS supplementation, higher concentrations of PHA being required for optimum response when the concentration of FCS was increased.While variability within preparations was small there was considerable variation in the magnitude of the response between preparations, which was sufficient to confound comparisons between different experiments and between animals. The variability between preparations could not be attributed to changes in sensitivity of PBL to mitogens or to the influence of erythrocyte contamination of the PBL preparations. While these results are in general agreement with previous reports of optimal conditions for the measurement of ruminant PBL to mitogens, there are some important differences which are discussed in the context of the available literature.  相似文献   

15.
In rodents and humans, lymphocytes circulate throughout the body and return preferentially to their tissues of origin via a process termed homing. The specificity of homing is controlled by the binding of tissue-specific receptors on lymphocytes to ligands on specialized high-walled endothelial venules (HEV) found in lymphoid tissue. The murine and human peripheral lymphocyte homing receptors (PLHR) have been characterized and shown to be similar to each other. We present evidence for a similar receptor in the bovine. Bovine peripheral blood lymphocytes (PBL) bind to the HEV of murine peripheral lymph node tissue in vitro. The same sugars that have been shown to decrease the binding of murine or human lymphocytes to murine HEV also decrease the binding of bovine PBL to murine HEV. Neuraminidase treatment affects lymphocyte binding in a similar manner in the bovine, murine and human species. Phorbol myristate acetate (PMA) stimulation, which has been shown to reduce the expression of murine and human PLHR, also reduces the binding of bovine PBL to murine HEV. These data suggest conservation of PLHR between these species.  相似文献   

16.
The effects of corticosteroids on the chemiluminescence response of bovine phagocytic cells were determined both in vitro and in vivo. The in vitro addition of hydrocortisone or dexamethasone had no significant effect on the chemiluminescence response of leukocytes in a whole blood or purified polymorphonuclear leukocyte (PMN) population. Cattle that received a single 20 mg dose of dexamethasone or three 20 mg doses of dexamethasone (given 24 hours apart) demonstrated the expected effects on the bovine leukogram (leukocytosis, neutrophilia, lymphopenia, eosinopenia, and monocytosis) and also demonstrated the expected suppressive effect on lymphocyte response to phytohemagglutinin (PHA). However, neither a single nor multiple dexamethasone treatment(s) had an effect on the chemiluminescence response of phagocytes in whole blood, but significantly enhanced the chemiluminescence response of the purified PMN leukocyte population. There was no significant difference between the two dexamethasone treatment groups in either the degree or duration of the effects observed in the chemiluminescence or lymphocyte response assays.  相似文献   

17.
Ponies were evaluated for their response to feed withholding and exogenous administration of corticosteroids (dexamethasone 0.04 mg/kg intramuscular [IM]) in an attempt to reproduce the hyperlipemia syndrome. Because insulin resistance has been associated with hyperlipemia, all ponies were initially evaluated for insulin response to an oral glucose load and normal dexamethasone suppression of serum cortisol. Four ponies were identified as hyperinsulinemic reflecting insulin resistance. All ponies had suppressed cortisol concentrations following dexamethasone administration. Feed withdrawal resulted in hypertriglyceridemia by 48 hours in all ponies. Very low density lipoprotein-triglyceride (VLDL) fraction was primarily elevated. The administration of dexamethasone failed to increase the degree of triglyceridemia. Although insulin resistance has been proposed as the likely cause of the hypertriglyceridemia in ponies, in this study four of eight ponies were considered to have normal insulin responses and yet still developed hypertriglyceridemia.  相似文献   

18.
Detection of bovine virus diarrhoea virus (BVDV) in one vaccinated beef cattle and three non-vaccinated dairy herds was investigated on peripheral blood leukocytes (PBL) with or without previous treatment followed by a capture ELISA (cELISA). Using the combination of PHA and polycation treatment, PBL from 229 seropositive cattle were studied and could be classified in four different states of BVDV infection. Lysed PBL from four animals were directly positive in cELISA (Category I), PBL of 17 animals were positive after PHA stimulation (Category II), 15 animals were positive only after PHA stimulation plus polycation treatment (Category III), while virus could not be detected in 193 seropositive cattle. Wild-type BVDV strains were isolated by co-culture on polycation-treated MDBK cells from 11 of these seropositive animals. BVDV antibodies of these same animals were able to neutralize their own virus, indicating that virus persists in PBL in spite of strain-specific antibodies. No apparent change of leukocyte subpopulations could be detected in any category of virus-positive animals. Thus, BVDV may be present in the PBL of some cattle, even in the presence of a specific active immune response.  相似文献   

19.
Peripheral blood lymphocytes were isolated from healthy calves and were subsequently infected with sporozoites of Theileria annulata in vitro. The infected cells were passaged for 50 times and thereafter inoculated into animals from which they were previously isolated. Within 4-5 days, schizont-containing cells were demonstrable in the lymph nodes of all animals. Few days later, merozoites were detected in erythrocytes. A slight decrease in the counts of lymphocytes and leucocytes was also found. After 2 months these animals and a group of uninfected calves were heavily infected by tick-infestation and showed severe symptoms of theileriosis with 60% schizont-containing cells in the lymph nodes and a parasitaemia of about 35%. Because of the severity of the infection, all control calves were treated with Halofuginone. In contrast, the initially immunized cattle (by inoculation of culture cells), survived the infection without chemotherapy. Less than 10% of their lymph node cells contained schizonts, whereas less than 1% of their erythrocytes were found to be infected with merozoites. In all immunized animals, specific cytotoxic PBL, with the capacity to lyse autologous but not allogeneic infected cells, were demonstrated. In addition, a population of PBL were found to be able to inhibit the growth of T.annulata-infected culture cells in vitro. However, in comparison to PBL of immune animals, PBL of acute infected calves were superior in their capacity to inhibit the proliferation of schizont-containing cells. In mixed lymphocyte reactions, T. annulata-infected cells could induce a more pronounced proliferative response in PBL from immune than in PBL of uninfected animals.  相似文献   

20.
Bovine milk lymphocytes are less responsive to in vitro mitogen stimulation than peripheral blood lymphocytes (PBL). In this study, milk leukocytes (ML) or their soluble products, were co-cultured with mitogen stimulated PBL to determine if suppression could be transferred to normally responsive cells. Addition of either ML (treated with mitomycin C to prevent cell division), or supernatant from ML cultures to cultures of autologous PBL resulted in a reduction of mitogenesis by the PBL, but no suppression was seen with addition of treated PBL or PBL supernatant. Suppression was greater when the ML were from animals with chronic staphylococcal infection. Suppression by ML supernatant was not due to toxicity to the responders, since addition at the latter stages of culture had no effect on the response. These results indicate that reduced mitogenesis by milk lymphocytes may be due to the presence of suppressor cells or molecules.  相似文献   

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