Effect of calf thymus extract and zinc supplementation on the cellular response of mice exposed to restraint stress

The studies were carried out on Balb/c mice exposed to restraint stress twice for 12 h at 24 h intervals. Prior to stress exposure, the mice were treated with calf thymus extract (TFX - Jelfa) i.p. at a dose of 10 mg/kg, ten times at 24 h intervals. TFX was used per se or with zinc ions interaction, by adding zinc ions (as sulfate salt) to drinking water at a dose of 72 microg/mouse per day. The results obtained show that restraint stress dramatically decreased the total number of thymocytes and splenocytes which is also accompanied by decreasing weight ratio of the thymus and spleen. The decreasing number of thymic and spleen cells corresponded to a diminishing percentage of immature, double-positive CD4+CD8+ thymocytes, mature single-positive CD4+ thymic cells and CD4+, CD8+ and CD19+ splenocytes. Changes in the number of thymic cells affect their activity, which is expressed as a decreased proliferative response of thymocytes stimulated in vitro with concanavalin A (Con A) and phytohaemagglutinin (PHA). Besides, exposure to the restraint stress decreased interleukin-1 (IL-1) production by murine intraperitoneal macrophages stimulated in vitro with lipopolisacharide (LPS) from E. coli. Previous treatment with TFX counteracted restraint stress-induced immunosuppression, which is expressed as partial normalisation of the total number of thymic and spleen cells, accelerated regeneration of these two lymphatic organs, shortned suppressive action of restraint stress on the percentage of immature CD4+CD8+ thymocytes and CD4+ splenocytes and in total normalisation of the CD4+ thymocytes and CD8+ splenocytes. TFX administered prior to restraint stress not only counteracted the suppresive effects of stress on the proliferative activity of thymic cells stimulated in vitro with Con A and PHA, but also augmented the proliferative response of these cells to two mitogens. The immunorestorative effect of TFX was augmented by zinc supplementation.     

Effects of thymomimetic drugs and zinc supplementation on the cellular immune response in hydrocortisone-suppressed mice

The studies were carried out on Balb/c mice (5-6 weeks of age) exposed to immunosuppression by a single intraperitoneal dose (125 mg/kg) of hydrocortisone. Prior to hydrocortisone injection the mice were treated with diethyldithiocarbamate (DTC) intra-peritoneally at a dose of 20 mg/kg, five times at 48 h intervals or calf thymus extract (TFX) at a dose of 10 mg/kg, 10 times at 24 h intervals. The two drugs were used per se or in zinc ions interactions, by adding zinc ions (as sulphate salt) to drinking water at a dose of 72 microg/mouse per day. The results obtained in the study show that hydrocortisone injection drastically decreases the number of thymocytes and splenocytes, which is also accompanied by a decreasing weight ratio of the thymus and spleen. The decreasing number of thymic and spleen cells corresponds to a decreasing percentage of CD4+, CD8+ and CD19+ splenocytes and double positive CD4+CD8+ thymocytes. Changes in the number of thymic cells affect their activity, which is expressed in a decreased proliferative response of thymocytes stimulated in vitro with concanavalin A (Con A) and phytohaemagglutinin (PHA). It has also been found that a single hydrocortisone dose decreases interleukin (IL)-1 production by murine intraperitoneal macrophages stimulated in vitro with lipopolysaccharide (LPS) from Escherichia coli. TFX or DTC counteract hydrocortisone-induced immunosuppression, which is expressed in partial normalization of the total number of thymic and spleen cells, accelerated regeneration of the two lymphatic organs, shorter suppressive action of hydrocortisone on the percentage of CD4+, CD8+ splenocytes and double positive (CD4+CD8+) and CD4+ thymocytes. Furthermore, total counteraction against the suppressive action of hydrocortisone to proliferative activity of thymocytes stimulated in vitro with Con A and PHA was observed. TFX administered prior to hydrocortisone injection partially prevented the suppressive action of the drug on IL-1 production by intraperitoneal macrophages, but such an effect was not observed with DTC. The immunorestorative effect of TFX and DTC was augmented by zinc supplementation. The results obtained in the study show that neither TFX nor DTC administration per se and in interaction with zinc supplementation were able to change the suppressive effect of hydrocortisone on the percentage of B splenocytes (CD19+ cells).     

Comparative effects of fluoroquinolones on subsets of T lymphocytes in normothermic and hyperthermic mice

The subsets of T lymphocytes in thymus, spleen and mesenteric lymph nodes were investigated in normothermic and hyperthermic mice treated with fluoroquinolones administered orally six times at 24 h intervals at doses of 15 or 75 mg/kg (flumequine, norfloxacin and ciprofloxacin) and 5 or 25 mg/kg (enrofloxacin). It has been found that fluoroquinolones can modulate CD3+, CD4+ and CD8+ marker expression on thymocytes, splenocytes and lymphocytes of mesenteric lymph nodes. Flumequine (15 mg/kg) decreased the percentage of immature CD4+CD8+ thymic cells and increased the percentage of mature CD4+ and CD8+. When the dose of flumequine was increased to 75 mg/kg a reduction in the maturation of thymocytes was observed. Administration of flumequine, norfloxacin and ciprofloxacin, irrespective of doses applied, increased the percentages of CD3+ splenocytes of CD4+ spleen cells. Exposure to enrofloxacin decreased the percentage of T helper-inducer cells. Flumequine and ciprofloxacin augmented the percentage of CD3+ mesenteric lymph node cells and increased the percentage of CD8+ cells. In contrast, norfloxacin and enrofloxacin decreased the percentage of CD3+ mesenteric lymph node cells and the percentage of CD4+ cells. Lipopolysaccharide (LPS) from E. coli (25 micro g/mouse) increased the percentage of single-positive CD4+ thymocytes, but did not affect the percentage of CD3+, CD4+ and CD8+ splenocytes and mesenteric lymph node cells. Flumequine and ciprofloxacin administered to mice pior to LPS potentiated its stimulant effect on the maturation of thymic cells ( increased percentage of mature CD4+ and CD8+ thymocytes). Pre-treatment with norfloxacin or enrofloxacin either reduced or did not modify the stimulant effect of LPS on maturation of thymic cells. Flumequine, norfloxacin, enrofloxacin and ciprofloxacin administered prior to LPS decreased the percentage of CD8+ splenocytes and increased the percentage of CD4+ spleen cells. Norfloxacin and ciprofloxacin at a dose of 75 mg/kg reduced the percentage of CD8+ mesenteric lymph node cells in hyperthermic mice. Pretreatment with norfloxacin at a dose of 15 mg/kg augmented the percentage of mesenteric lymph node cells. It was concluded that the modulating effects of fluoroquinolones depends on the chemial structure of drugs, dose administered as well as immunologic status.     

Influence of bestatin, an inhibitor of aminopeptidases, on T and B lymphocyte subsets in mice

Bestatin, a low-molecular weight dipeptide, is a potent inhibitor of aminopeptidase N which has been demonstrated to have antitumor and immunomodulatory effects. The effects of bestatin (10, 1 and 0.1 mg/kg) administered intraperitoneally once, five or ten times to mice on the total number of lymphocytes in the thymus, spleen and mesenteric lymph nodes and the percentage and the absolute number of T cell subsets (CD4+CD8+, CD4-CD8-, CD4+, CD8+) in the thymus and T (CD3+, CD4+, CD8+) and B (CD19+) lymphocytes in the spleen and mesenteric lymph nodes were studied. It has been found that bestatin administered ten times at doses of 10, 1 and 0.1 mg/kg increased the total number of thymocytes, splenocytes and lymphocytes of mesenteric lymph nodes. Bestatin also changed the percentage and the absolute number of T cell subsets in the thymus and T and B lymphocytes in the peripheral lymphatic organs. Five and ten exposures to bestatin (10, 1 and 0.1 mg/kg) increased the absolute count of both immature CD4+CD8+ and CD4-CD8- thymic cells. Moreover, both a single and multiple administration of bestatin (1 and 0.1 mg/kg) decreased the percentage and absolute count of CD3+ splenocytes and mesenteric lymph node cells with corresponding decreases in the percentage and absolute count of CD4+ and CD8+ cells. Both a single and multiple administration of bestatin at all the doses under investigation augmented the percentage and the absolute count of CD19+ (B lymphocytes) in the peripheral lymphatic organs. The results of the study show that there is a relationship between the effect induced by bestatin and the dose of the drug as well as the number of doses applied. The strongest effect on the T and B lymphocyte subsets was noted after five injections of bestatin at doses of 1 and 0.1 mg/kg.     

Influence of betulinic acid on lymphocyte subsets and humoral immune response in mice

Betulinic acid is a pentacyclic triterpene found in many plant species, among others, in the bark of white birch Betula alba. Betulinic acid was reported to display a wide range of biological effects, including antiviral, antiparasitic, antibacterial, anticancer and anti-inflammatory activities. The effects of betulinic acid (50, 5, 0.5 mg/kg) administered orally five times at 24 hours intervals to non-immunized and red blood cells (SRBC)-immunized mice were determined. The present study examined the total number of lymphocytes in the thymus, spleen and mesenteric lymph nodes, and the percentage of subsets of T cells (CD4+CD8+, CD4CD8, CD4+, CD8+) in thymus,T (CD3+, CD4+, CD8+) and B (CD19+) lymphocytes in the spleen and mesenteric lymph nodes, as well as white blood cell (WBC) and differential leukocyte counts in non-immunized mice, and humoral immune response in SRBC-immunized mice. SRBC was injected 24 hours after administration of the last dose of betulinic acid. It was found that betulinic acid administered orally five times at the dose of 0.5 mg/kg increased the total number of thymocytes, splenocytes, lymphocytes of mesenteric lymph node cells, and the weight ratio of the spleen and mesenteric lymph nodes in non-immunized mice. Betulinic acid also changed the percentage of T cell subsets in the thymus and T and B lymphocytes in peripheral lymphatic organs. The effects of betulinic acid on T and B cell subpopulations depended on the dose applied. The strongest stimulating effect of betulinic acid was observed when the drug was administered at the dose of 0.5 mg/kg. Five exposures to betulinic acid (0.5 mg/kg) decreased the percentage of immature CD4+CD8+ thymic cells with corresponding increases in the percentage and absolute count of mature, single-positive CD4+ thymocytes and decreased the percentage and total count of CD3+ splenocytes and mesenteric lymph node cells with corresponding decreases in the percentage and absolute count of CD4+ and CD8+ cells. Multiple administration of betulinic acid at the investigated doses augmented the percentage and absolute count of CD19+ cells in the peripheral lymphatic organs. Moreover, betulinic acid at the dose of 5 mg/kg administered prior to SRBC immunization increased the number of plaque forming cells (PFC) but decreased the production of anti-SRBC antibodies on day 4 after priming. Thus, betulinic acid is a potential biological response modifier and may strengthen the immune response of its host.     

Effects of Thymomimetic Drugs and Zinc Supplementation on the Cellular Immune Response in Hydrocortisone‐suppressed Mice

The studies were carried out on Balb/c mice (5–6 weeks of age) exposed to immunosuppression by a single intraperitoneal dose (125 mg/kg) of hydrocortisone. Prior to hydrocortisone injection the mice were treated with diethyldithiocarbamate (DTC) intra‐peritoneally at a dose of 20 mg/kg, five times at 48 h intervals or calf thymus extract (TFX) at a dose of 10 mg/kg, 10 times at 24 h intervals. The two drugs were used per se or in zinc ions interactions, by adding zinc ions (as sulphate salt) to drinking water at a dose of 72 μg/mouse per day. The results obtained in the study show that hydrocortisone injection drastically decreases the number of thymocytes and splenocytes, which is also accompanied by a decreasing weight ratio of the thymus and spleen. The decreasing number of thymic and spleen cells corresponds to a decreasing percentage of CD⁴⁺, CD⁸⁺ and CD¹⁹⁺ splenocytes and double positive CD4⁺CD⁸⁺ thymocytes. Changes in the number of thymic cells affect their activity, which is expressed in a decreased proliferative response of thymocytes stimulated in vitro with concanavalin A (Con A) and phytohaemagglutinin (PHA). It has also been found that a single hydrocortisone dose decreases interleukin (IL)‐1 production by murine intraperitoneal macrophages stimulated in vitro with lipopolysaccharide (LPS) from Escherichia coli. TFX or DTC counteract hydrocortisone‐induced immunosuppression, which is expressed in partial normalization of the total number of thymic and spleen cells, accelerated regeneration of the two lymphatic organs, shorter suppressive action of hydrocortisone on the percentage of CD⁴⁺, CD⁸⁺ splenocytes and double positive (CD4⁺CD⁸⁺) and CD⁴⁺ thymocytes. Furthermore, total counteraction against the suppressive action of hydrocortisone to proliferative activity of thymocytes stimulated in vitro with Con A and PHA was observed. TFX administered prior to hydrocortisone injection partially prevented the suppressive action of the drug on IL‐1 production by intraperitoneal macrophages, but such an effect was not observed with DTC. The immunorestorative effect of TFX and DTC was augmented by zinc supplementation. The results obtained in the study show that neither TFX nor DTC administration per se and in interaction with zinc supplementation were able to change the suppressive effect of hydrocortisone on the percentage of B splenocytes (CD19⁺ cells).     

Modulation of murine macrophages and T lymphocytes by lysozyme dimer

The effects of lysozyme dimer (2 and 20 microg/kg) administered i.p. once and four times to mice on the phagocytic and killing ability of peritoneal macrophages, interleukin-1 (IL-1) production by murine macrophages stimulated in vitro with lipopolisaccharide of E. coli and expression of thymocyte, splenocyte and mesenteric lymphonode cell CD3+, CD4+ and CD8+ markers were studied. It was found that lysozyme dimer administered once or four times at doses of 2 microg/kg and 20 microg/kg augments the phagocytic and killing activity of peritoneal macrophages. The strongest stimulating effect was noted after four injections of lysozyme dimer at a dose of 20 microg/kg. Moreover, lysozyme dimer is able to modulate the production of IL-1 by murine macrophages stimulated in vitro with LPS. Exposure to four doses of lysozyme dimer (20 microg/kg) enhances the synthesis and release of IL-1, but this drug administered once (2 microg/kg and 20 microg/kg) or four times (2 microg/kg) decreases IL-1 production by peritoneal macrophages. It was also found that administration of lysozyme dimer at a dose of 20 microg/kg, irrespective of the number of doses applied, increases the percentage of CD4+ thymocytes and splenocytes. Moreover, exposure to four doses of lysozyme dimer (2 and 20 microg/kg) increases the percentage of CD4+ and CD8+ mesenteric lymphonode cells.     

The effects of florfenicol on lymphocyte subsets and humoral immune response in mice

Florfenicol is a broad-spectrum bacteriostatic antibiotic used in domestic animals. The aim of the study was to determine the effect of florfenicol on the total number of lymphocytes in the thymus, spleen and mesenteric lymph nodes and the percentage and the absolute number of T cell subsets (CD4+CD8+, CD4-CD8-, CD4+, CD8+) in the thymus and T (CD3+, CD4+, CD8+) and B (CD19+) lymphocytes in the peripheral lymphatic organs in non-immunized mice and humoral immune response in sheep red blood cells (SRBC)-immunized mice. Florfenicol was administered orally at a dose of 30 mg/kg six times at 24 h intervals to non-immunized mice and four or seven times at 24 h intervals to SRBC-immunized mice. SRBC was injected 2 hours prior to the first dose of the drug. Florfenicol increased the percentage of CD4CD8- thymocytes and the absolute number of CD4+ and CD8+ thymocytes on day 7. The increased percentage and absolute number of CD3+, CD4+ and CD8+ lymphocytes in mesenteric lymph nodes and decreased percentage of lymphocytes B were also observed 24 hours from the last administration of florfenicol. Florfenicol administered after SRBC immunization reduced the number of plaque forming cells (PFC) and the production of anti-SRBC antibodies on days 4 and 7 after priming.     

Modulatory effects of chitosan adipate on the T and B lymphocyte subsets in mice

This study examined the subsets of T lymphocytes in the thymus, spleen and mesenteric lymph nodes as well as the subsets of B lymphocytes in the spleen and mesenteric lymph nodes in mice administered chitosan adipate (20 mg/kg) intraperitoneally once or four times at 24 h intervals. The results showed that chitosan adipate decreased the percentage of immature CD4⁺CD8⁺ thymic T cells and increased the percentage of mature CD4⁺ and CD8⁺ thymocytes. The most significant stimulating effect was observed after four injections. A single exposure to chitosan adipate increased the percentage of CD4⁺ mesenteric lymph node cells, but four injections of the drug increased the percentage of CD4⁺ and CD8⁺ mesenteric lymph node cells. Chitosan adipate had no effect on the subset of splenic T cells. In contrast, chitosan adipate administered either once or four times increased the percentage of CD19⁺ splenocytes but had no effect on the percentage of CD19⁺ mesenteric lymph node cells. Overall, chitosan adipate induces the maturation and differentiation of thymocytes, and regulates the number of B splenic cells and lymph node T cells irrespective of the number of doses.     

Peripheral blood mononuclear cell subsets during Trichinella spiralis infection in pigs

The immune response of 'Yugoslav meat breed' pigs inoculated with low doses of Trichinella spiralis muscle larvae was followed over two to nine weeks of primary infection, by analysing changes in peripheral blood mononuclear cell subsets, the development of a humoral antibody response and muscle larvae burden. During the course of the infection, infected animals showed a persistent elevation of both CD4+ and CD8+ T cell subsets from days 15 to 60 after the parasite exposure. During this time, the number of peripheral blood mononuclear cells expressing major histocompatibility complex class II antigens was also increased, while no significant differences were found in the number of circulating monocytes/macrophages and B cells over time. Humoral antibody responses to muscle larvae excretory-secretory products were evident as early as 41 days after infection, while the muscle larvae were recovered as early as 27 days after infection. The increased levels of CD4+ and CD8+ T cell subsets, as well as cells expressing major histocompatibility complex class II antigens in pigs exposed to T spiralis, may be indicative of some considerable alterations in cell subsets that are involved in the regulation of the swine immune response to this parasite.     

Differences in the kinetics of T cell accumulations in C3H/HeN (Bcg-resistant) and C57BL/6 (Bcg-susceptible) mice infected with Mycobacterium paratuberculosis

The accumulation of various T cell subsets in Bcg-susceptible (C57BL/6) and -resistant (C3H/HeN) strains of mice were compared following an intraperitoneal infection with Mycobacterium paratuberculosis. Groups of mice from both strains were killed at 3, 5, 10, 15, 30, and 150 days after infection and lymphocytes were harvested from the peritoneal exudate cells (PEC), spleen, intestinal epithelial lymphocytes (IEL), lamina propria lymphocytes (LPL), Peyer's patches, and mesenteric lymph node (MLN) and labelled with monoclonal antibodies to CD3, CD4, CD8, γδ TCR, CD25, and CD44 for flow cytometric analysis. Uninfected C3H/HeN mice had higher proportions of CD4+ cells in the spleen, MLN, LPL, IEL and Peyer's patches, while uninfected C57BL/6 mice had higher proportions of CD8+ and/or γδ T cells. Significant increases in accumulation of CD8+ and γδ T cells were detected in the peritoneum and other tissues in both strains of mice after infection. Higher CD4/CD8 ratios were observed in most lymphoid tissues of C3H/HeN mice, while increased proportions of CD8+ and/or γδ T cells were present in C57BL/6 mice. These results indicate that significant differences in T cell profiles exist between these two strains of mice, both inherently and in response to infection with M. paratuberculosis. Innately lower levels of CD4+ cells and/or higher percentages of CD8+ and γδ T cells may play a role in the increased susceptibility of C57BL/6 mice to infection with M. paratuberculosis.     

Characterization of the gastric immune response in cheetahs (Acinonyx jubatus) with Helicobacter-associated gastritis

Captive cheetahs have an unusually severe progressive gastritis that is not present in wild cheetahs infected with the same strains of Helicobacter. This gastritis, when severe, has florid lymphocyte and plasma cell infiltrates in the epithelium and lamina propria with gland destruction, parietal cell loss, and, in some cases, lymphoid follicles. The local gastric immune response was characterized by immunohistochemistry in 21 cheetahs with varying degrees of gastritis. The character of the response was similar among types of gastritis except that cheetahs with severe gastritis had increased numbers (up to 70%) of lamina proprial CD79a+CD21- B cells. CD3+CD4+ T cells were present in the lamina propria, and CD3+CD8α+ T cells were within the glandular epithelium. Lymphoid aggregates had follicular differentiation with a central core of CD79a+/CD45R+ B cells and with an outer zone of CD3+ T cells that expressed both CD4 and CD8 antigens. MHC II antigens were diffusely expressed throughout the glandular and superficial epithelium. No cheetah had evidence of autoantibodies against the gastric mucosa when gastric samples from 30 cheetahs with different degrees of gastritis were incubated with autologous and heterologous serum. These findings indicate that T-cell distribution in cheetahs is qualitatively similar to that in other species infected with Helicobacter but that large numbers of lamina propria activated B cells and plasma cells did distinguish cheetahs with severe gastritis. Further research is needed to determine whether alterations in the Th1:Th2 balance are the cause of this more plasmacytic response in some cheetahs.     

Alteration of helper T-cell related cytokine production in splenocytes during Trichinella spiralis infection

Infection by Trichinella spiralis takes place in two distinct phases: one is the intestinal phase and the other is the muscle phase. To evaluate alterations in cytokine production during a T. spiralis infection, we periodically assessed the cytokine production of splenocytes in mice after infection (AI). The levels of Th2-related cytokines immediately increased after the initiation of T. spiralis larval intestinal invasion (1 week AI). These early elevations in the Th2 response might be associated with the innate immune responses of intestine epithelial cells against T. spiralis larval invasion. IL-4 and IL-13 levels reached a peak prior to the initiation of nurse cell formation (2 weeks AI). Additionally, all Th17-related cytokines, except for IL-17, increased slightly until 2 weeks AI. However, expression levels for all of the Th2 and Th17-related cytokines began to decrease after the initiation of nurse cell formation and reached basal levels at 4 weeks AI, except for IL-5. At the same time, the CD4(+)CD25(+)Foxp3(+) T (regulatory T, T(reg)) cell population increased significantly in the spleen. Additionally, the number of cells in the peripheral lymph nodes increased. In conclusion, T. spiralis larva intestinal invasion induced the production of Th2 and Th17 cell-related cytokines, and the cytokines decreased with T(reg) cell-related cytokine.     

Development of the B- and T-cell compartments in porcine lymphoid organs from birth to adult life: an immunohistological approach.

Using immunohistological techniques, we studied the development over time of B- and T-cell compartments in the lymphoid organs of specific-pathogen-free pigs. Tissue samples were collected at various time-points, starting 2 days before the pigs were born until the pigs were 10 months old. The samples were collected from the spleen, thymus, peripheral lymph node, mesenteric lymph node, duodenum, jejunum, ileum, jejunal Peyer's patch and ileal Peyer's patch. Monoclonal antibodies specific to B- and T-cells were used to identify where the following cells were localized: IgM-B cells (cells positive to surface immunoglobulin), IgM-, IgG- and IgA-containing cells (cells positive to cytoplasmic immunoglobulin), and CD2-, CD4- and CD8-positive cells. The development of the B- and T-cell subpopulations in each organ was analysed. Two days before birth, most organs contained quantities of IgM-B cells. The spleen, lymph nodes, Peyer's patches and, notably, the thymus, contained some immunoglobulin-containing cells (Ig-CC); this finding indicates that pigs have cells that secrete immunoglobulins before birth. Just after birth, the incidence of Ig-CC increased in most organs; first IgM-CC increased, then either IgG- or IgA-CC increased, depending on the organ. T-cell development was observed clearly in spleen and in the lamina propria of the small intestine, in contrast to other organs, in which the T-cell compartments containing various T-cell subpopulations were well developed before birth. Comparison of the incidence of CD4+ and CD8+ cells showed that the CD4:CD8 ratio of these cells in the spleen, lymph nodes, Peyer's patches and small intestine is low, especially in adult pigs, compared with the CD4:CD8 ratio in other species. Weaning had little influence on the incidence of B- and T-cells in lymphoid organs. This study is the first immunohistological survey to describe the development of the major B- and T-cell subpopulations in various lymphoid organs of pigs, and it should be useful for future immunopathological and comparative immunological studies in pigs.     

Proventriculitis in broiler chickens: immunohistochemical characterization of the lymphocytes infiltrating the proventricular glands

Broiler chickens with transmissible proventriculitis have severe lymphocytic infiltration of the proventricular glands. The distribution of T cells and B cells in these infiltrates was studied histopathologically, and their identity was confirmed immunohistochemically (CD3, CD4, CD8, and B cells). To reproduce this disease, 1-day-old commercial boilers were orally gavaged with homogenized proventriculi from broilers with proventriculitis. Resulting lesions were examined at both acute (7 days postinoculation [i]) and chronic (14 and 21 dpi) time points. Lymphocytic infiltrates in the proventricular glands and the mucosal lamina propria were present at all time points and were most prominent and demarcated at 14 dpi. T and B lymphocytes were present during acute and chronic proventriculitis, but their distribution varied within the glands. Lymphocytic infiltrates in the proventricular glands and in the lamina propria were predominantly CD3+T cells, and most of these were also CD8+. B cells and CD4+ T cells formed aggregates in chronic proventriculitis. Thus, both cell-mediated and humoral immune responses are induced during transmissible proventriculitis, and the cell-mediated immune response is morphologically greater.     

Immunoperoxidase studies of cell mediated immune effector cell populations in early Mycobacterium avium subsp. paratuberculosis infection in sheep

Immunoperoxidase (IPX) labelling for CD4, CD8, TCR-gammadelta, WC1, CD1b, IFN-gamma, CD45R, CD56 and lysozyme was used to investigate changes in cell mediated immune effector cell populations in the intestinal Peyer's patches (PP) and mesenteric lymph nodes of lambs, 2 and 4 months after experimental infection with low doses of sheep strain Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis). The organism was cultured from the tissues of each infected lamb, but histological lesions were not present. This infection model was considered to be more representative of natural M. a. paratuberculosis infection than previous studies. Infected sheep had significantly more CD4+ cells in the mucosa, domes and interfollicular areas of the terminal ileum, and in the interfollicular areas of the jejunal Peyer's patch. Infected sheep also had significantly increased numbers of TCR-gammadelta+ cells in the mucosa and interfollicular areas of the jejunal Peyer's patch, and increased numbers of WC1+ cells in the ileal Peyer's patch. These findings are consistent with previous findings in sheep given higher doses of cattle strain M. a. paratuberculosis. Significantly fewer CD1b+ cells were present in the paracortical areas of the mesenteric lymph nodes of infected sheep, and the reduction was greater in sheep infected for 4 months compared to sheep infected for only 2 months. Down-regulation of CD1b expression may be important for the continued survival and multiplication of M. a. paratuberculosis as specific adaptive immunity develops. Across all sheep, jejunal Peyer's patches had higher numbers of CD4+, CD8+, TCR-gammadelta+, WC1+ and CD45R+ cells, and lower numbers of CD56+ fibres compared to ileal Peyer's patches. These findings confirm and extend the peculiarities of the terminal ileal Peyer's patch in the young ruminant, with possible implications for the early establishment of M. a. paratuberculosis infection.     

不同储存方法对鼠肉内旋毛虫幼虫感染性影响

旋毛虫阳性小鼠的肌肉经不同方法储存后,为观察其对小鼠感染性的变化,取健康小白鼠20只随即分作4组,每组分别喂食新鲜、4℃冷藏、及-18℃冷冻,及腌制＋冷藏一定时间的旋毛虫阳性的小鼠腿肌肉约1g。饲养1～2周,剖杀,取其膈肌、腿肌镜下观察是否呈旋毛虫囊包阳性。结果显示,喂食新鲜旋毛虫阳性鼠肉的小鼠和喂食经过冷藏的阳性鼠肉的小鼠都感染了旋毛虫,而喂食经冷冻的和经腌制＋冷藏的鼠肉的小鼠均未感染旋毛虫,可见,将肉类冷冻或严格冷藏储存一定时间可杀死其中的旋毛虫,减弱其致病性,降低因食用疫肉而患病的风险。     

Murine model study of the practical implication of trypanosome-induced immunosuppression in vaccine-based disease control programmes

The relevance of trypanosome-induced immunosuppression in relation to the efficacy of vaccine-induced immunity was studied in mice. Mice were immunised with crude Trichinella spiralis muscle larvae homogenate vaccine and infected with T. spiralis and/or Trypanosoma brucei. Vaccination significantly decreased adult worm burden (p<0. 05) and accelerated worm expulsion in mice infected with T. spiralis only. T. brucei superinfection resulted in monocytosis, suppressed eosinophilia, significant decrease in PCV (p<0.001), higher numbers of adult worms (p<0.001) and failure to expel all adult worms by Day 12 post infection (p.i.). Regardless, they produced anti-Trichinella IgG(1) responses similar to those of the vaccinated non-T. brucei-infected group. T. brucei also suppressed the proliferative responses of spleen cells to stimulation with Con A and T. spiralis antigen, and induced strong production of interferon-gamma (IFN-gamma) in culture supernatants of antigen stimulated spleen and mesenteric lymph node cells. Interleukin-5 (IL-5) production was suppressed by T. brucei in supernatants of Con A- and antigen-stimulated spleen cells. It was concluded that trypanosome infections and the associated immunosuppression are of great practical significance in trypanosome endemic areas, especially with regards to disease control programmes involving vaccine-induced herd immunity.     

Effect of infection of turkeys with haemorrhagic enteritis adenovirus isolate on the selected parameters of cellular immunity and the course of colibacillosis

The aim of the study was to determine the effect of a Polish low-virulence isolate of haemorrhagic enteritis adenovirus (HEV) on the immune system in turkeys and on the course of colibacillosis in birds infected under laboratory conditions. Turkeys were infected per os with HEV at the dose of 10(4.3)EID50/mL and with E. coli (APEC) (serotypes 078:K80:H9) at the dose of 4x10(9)CFU/mL by injection to the thoracic air sac. The birds infected with the HEV were infected with the APEC either simultaneously or after 5 days. Five days after HEV infection, the percentages of subpopulations of the CD3+CD4+ and CD3+CD8alpha+ T cells and the IgM+ B cells were determined in blood and spleens of the HEV-infected turkeys and in the control (uninfected) birds. The course of colibacillosis was more severe in turkeys infected with the APEC 5 days after infection with the HEV than in those infected with the HEV and APEC simultaneously and than in those infected only with APEC. Five turkeys out of the 18 infected with the APEC 5 days after infection with HEV, died. Their body weights were statistically significantly lower with higher FCR values 41 days after the infection in comparison to turkeys in the other groups. A considerable decrease in the percentage of the T and B cells subpopulations in the blood were found in turkeys infected with the HEV and while the percentage of CD3+CD4+ T cells subpopulation in the spleen increased significantly, the contribution of the CD3+CD8alpha+ T cells and IgM+ B cells subpopulations were decreased. These changes in the immune system of turkeys, occurring 5 days after infection with the HEV, made them more susceptible to infection with the APEC.     

A morphologic and immunohistochemical study of the bronchus-associated lymphoid tissue of pigs naturally infected with Mycoplasma hyopneumoniae

Porcine enzootic pneumonia (PEN), caused by Mycoplasma hyopneumoniae (Mh), has been described in pigs in all geographic areas. The disease is characterized by high morbidity and low mortality rates in intensive swine production systems. A morphologic and immunohistochemical study was done to determine the cellular populations present in lung parenchyma of infected pigs, with special attention to the bronchus-associated lymphoid tissue (BALT). Polyclonal and monoclonal antibodies were used for the detection of antigens of Mh, T lymphocytes (CD3+, CD4+, and CD8+), IgG+ or IgA+ lymphocytes, and cells containing lysozyme, S-100 protein, major histocompatibility complex class II antigen or myeloid-histiocyte antigen. Findings in lung tissues associated with Mh infection were catarrhal bronchointerstitial pneumonia, with infiltration of inflammatory cells in the lamina propria of bronchi and bronchioles and alveolar septa. Hyperplasia of mononuclear cells in the BALT areas was the most significant histologic change. The BALT showed a high morphologic and cellular organization. Macrophages and B lymphocytes were the main cellular components of germinal centers. T lymphocytes were primarily located in perifollicular areas of the BALT, lamina propria and within the airway epithelium, and plasma cells containing IgG or IgA at the periphery of the BALT, in the lamina propria of bronchi and bronchioles, in alveolar septa, and around bronchial submucosal glands. The hyperplastic BALT in PEN cases consisted of macrophages, dendritic cells, T and B lymphocytes, and IgG+ and IgA+ plasma cells. CD4+ cells predominated over CD8+ cells. Local humoral immunity appears to play an important role in the infection.