Immunofluorescence studies of renal basement membranes in dogs with spontaneous diabetes

Renal tissue from 12 dogs with spontaneous diabetes and 16 control dogs were studied by light, immunofluorescence, and electron microscopies. Significant linear staining for immunoglobulin G and albumin were observed in the glomerular and tubular basement membranes of dogs with spontaneous diabetes--similar to that observed in human diabetes. On immunohistochemical grounds, it would appear that the dog with spontaneous diabetes is an appropriate model of diabetes in persons.     

Antitubular basement membrane autoantibody in a dog with chronic tubulointerstitial nephritis

Linear deposition of immunoglobulin G was seen by direct immunofluorescence along the tubular basement membranes in the kidney of a dog with chronic tubulointerstitial nephritis. Autoantibody eluted from the affected kidney bound to the tubular basement membrane of normal canine kidney, but not to several other normal canine basement membranes. The pathogenic significance of the autoantibody in this dog was not determined.     

Antibodies to Aujeszky's disease virus in pigs immunized with purified virus glycoproteins

Antibodies to Aujeszky's disease virus (ADV) glycoproteins gII, gIII, and gp50 were compared using four in vitro tests. Antibodies generated by vaccination with a modified-live vaccine (MLV) were also compared. The serological assays employed were: serum neutralization test (SNT), complement facilitated serum neutralization test (C'SNT), complement-mediated cytolysis and antibody dependent cellular cytotoxicity (ADCC). Pigs were immunized with single glycoproteins twice 14 days apart, or once with the modified-live vaccine. Fourteen days after the second immunization, sera were collected. Virus neutralizing activity (SNT) was demonstrated in the sera from all pigs immunized with gp50 and in one out of three immunized with gIII. Sera from the MLV group all had neutralization titers higher than animals immunized with single glycoproteins. Addition of guinea pig complement to the serum neutralization test (i.e., C'SNT) produced an enhancement of antibody titers in all groups except the pigs immunized with gIII. The complement-mediated cytolysis test rendered antibody titers similar in magnitude for all pigs immunized with single glycoproteins, but slightly lower than values for MLV vaccinated pigs. ADCC activity was clearly displayed in sera from pigs immunized with gIII or vaccinated with MLV, whereas sera from pigs immunized with gII or gp50 had a minimal response. The results indicate that the relative efficiency of antibodies against ADV glycoproteins in protection should be considered for selecting or producing gene-deleted strains for use in vaccine production.     

Blood cellular immune response in pigs immunized and challenged with Haemophilus parasuis

The cellular immune response to an experimental infection by Haemophilus parasuis, the etiological agent of Glässer’s disease in pigs, was characterized studying changes in peripheral blood mononuclear cells (PBMC) in colostrum-deprived pigs. Five groups were studied, four of those were previously immunized with different formulations and the fifth was maintained as non-immunized control. All groups were challenged with 5 × 10⁹ CFU of H. parasuis serotype 5. The non-commercial bacterin conferred a complete protection, while the OMP-vaccine and the exposure to a subletal dose of 10⁵ CFU of H. parasuis protected only partially, and the recombinant Tbp B-vaccine induced no protection. PBMC were analyzed using monoclonal antibodies against porcine CD45⁺, CD3⁺, CD4⁺, CD8α⁺, CD25⁺, CD4⁺ naïve, αIgM⁺ and SWC3⁺ cells in single-colour fluorescence, and CD4⁺/CD8α⁺ and CD8α⁺/CD8β⁺ combinations in two-colour fluorescence. The different groups showed no significant changes in PBMC subsets following vaccination, and only minor changes were encountered after challenge, consisting mainly of significant increases (P < 0.05) in the relative proportions of monocytes and granulocytes (SWC3⁺) and B cells (αIgM⁺), as well as a significant reduction in CD3⁺ cells (P < 0.05). These changes were similar for the five groups compared, except for the significant increase of CD25⁺ cells, which was only observed for the bacterin-vaccinated group. These results suggest an increase of trafficking of inflammatory cells and the onset of the adaptive antibody response against H. parasuis infection; in addition, the blood cellular response developed by the different groups was not relevant to protection.     

Infectious agents identified in pigs with multifocal interstitial nephritis at slaughter

One kidney was taken from each of 100 pigs at slaughter; 50 had gross lesions of multifocal interstitial nephritis and 50 had no gross lesions. Forty-nine of the affected kidneys had lesions that were characterised by the presence of either a few randomly distributed or numerous widely disseminated pale foci, 1 to 3 mm in diameter, on the cortical surface (white-dotted kidneys). Microscopically, these focal inflammatory lesions often had a distinct lymphofollicular pattern (follicular nephritis). Lesions of chronic vasculitis were observed in 21 of the affected kidneys. Histologically, the control kidneys had only small and sparse inflammatory foci. Standard bacterial cultures of kidneys of both groups were not significant, and cultures for the isolation of leptospires were all negative. Virological examination of the kidney homogenates by PCR did not reveal any porcine reproductive and respiratory syndrome virus and only a few cases were positive for the porcine circovirus type 1. However, porcine parvovirus (PPV) and porcine circovirus type 2 (PCV-2) were detected in many kidneys of both groups but in a significantly higher proportion of the kidneys with interstitial nephritis. There was a significant association between the lesions and the presence of PPV and PCV-2 with odds ratios of 7.5 (P<0.0001) and 3.4 (P=0.0074), respectively, and the odds ratio increased to 22.7 (P<0.0001) when both viruses were identified in the same kidney. However, a subsample of kidneys taken from both groups were negative by immunohistochemistry for the presence of PPV and PCV-2 antigens.     

Acute tubulo-interstitial nephritis in a dog after halothane anaesthesia and administration of flunixin meglumine and trimethoprim-sulphadiazine.

Acute tubulo-interstitial nephritis was diagnosed post mortem when a dog died four days after surgery for a femoral head resection. Possible causative factors associated with halothane anaesthesia, flunixin meglumine analgesia and prophylactic antibiotic therapy with trimethoprim-sulphadiazine are discussed. It is concluded that death was due to renal failure associated with tubulo-interstitial nephritis as a result of a combination of ischaemic and toxic events.     

Development of tertiary lymphoid structures in the kidneys of pigs with chronic leptospiral nephritis

Tertiary lymphoid organs (TLOs) are structures that are morphologically and functionally similar to secondary lymphoid organs. TLOs usually arise in a background of chronic inflammation. Several histological patterns of interstitial nephritis have been documented in porcine leptospirosis. Among them the lympho-follicular pattern is characterized by infiltrates of mononuclear cells organized in lymphoid follicle-like structures. Immunohistological analysis of 5 cases of porcine lympho-follicular nephritis associated with Leptospira Pomona infection demonstrated the presence of inflammatory cell populations, including B cells, T cells, macrophages and follicular dendritic cells (FDCs), which were compartmentalized as in TLOs. Immunohistochemistry for Leptospira Pomona revealed an intimate association between leptospiral antigen and FDCs. Overexpression of MHCII in different populations of both professional and non-professional antigen presenting cells was also demonstrated. FDCs play role during TLOs induction for their ability to retain non-self antigens in the form of immune complexes, thus causing persistent T cell activation, generation of a complex cytokine network and stimulation of humoral immunity. Sustained bacterial antigen presentation in the context of chronic leptospiral nephritis, may also lead to autoimmune mechanisms involved in the generation of TLOs. Whether lymphoid neogenesis and TLOs play a protective role in porcine leptospiral nephritis is still unclear.     

Induction of protective immunity in calves immunized with adult Oesophagostomum radiatum somatic antigens

Oesophagostomum radiatum, the nodular worm of cattle, is a severe pathogen in previously uninfected calves. However, cattle develop a strong protective immune response upon exposure to the parasite. In order to evaluate whether soluble parasite antigens could induce protective immunity, a soluble fraction was obtained from disrupted adult worms, and this fraction was used to vaccinate calves. The vaccination protocol involved two immunizations. The first was administered intramuscularly with complete Freund's adjuvant, the second was given intraperitoneally with antigen plus alum. This immunization reduced the number of worms developing from a subsequent challenge infection by 85% and also reduced clinical signs associated with infection with adult worms. However, vaccination resulted in decreased weight gains during the larval phase of the infection. Analysis of the immune response generated in the vaccinated calves indicated that protection from infection was significantly correlated with the levels of: (1) circulating parasite-specific IgG2 antibody; (2) cellular immune reactivity as determined in a conventional parasite-specific lymphocyte proliferation assay. Serum anti-O. radiatum IgG2 antibodies from vaccinated calves were used in immunoblots to identify the major immunogens. There were five major immunogens with molecular weights ranging from 70 to 150 kDa. Fractions separated by high-pressure liquid chromatography contained immunogens that were used to immunize calves. Vaccination with these fractions was found to impart the same level of protective immunity and induced similar IgG2 antibody and cellular immune responses as the crude whole worm extract even with 100-fold less protein.     

Cytokine expression in colostrum-deprived pigs immunized and challenged with Haemophilus parasuis

The expression of several cytokines in spleen, pharyngeal lymph nodes, lung and brain after different immunization procedures and a challenge with 5 × 10⁹ CFU of Haemophilus parasuis was compared. Five groups of colostrum-deprived pigs were used: vaccinated with (I) a bacterin, (II) an outer-membrane-protein-vaccine, (III) a recombinant transferring-binding protein B, (IV) exposed to a total dose of 10⁵ CFU, and (V) not previously immunized. All pigs in groups III and V died, while all animals in group I, most of group IV and half of group II survived until the end of the experiment. IL-1α was found in significantly higher levels (p < 0.05) in spleen, lymph nodes and brain of dead pigs, which could be explained by the major severity of lesions in these animals. However, IL-4, IL-10, TNF-α and IFN-γ were expressed in significantly higher levels by survivors (for all the four cytokines in lymph nodes; for IL-4, IL-10 and TNF-α in spleen; for IL-4, TNF-α and IFN-γ in lung, and only for TNF-α in brain), thus suggesting a role of these four cytokines in the adaptive response, which might contribute to protection against H. parasuis infection.     

Immunohistochemical distribution of antigens in liver of infected and immunized pigs with Ascaris suum

In the present work, we carry out an immunopathological study of the swine ascariosis, under different conditions (control, infection and immunization). Twenty-one Iberian pigs were used and divided in seven groups. Groups 1 and 2 were the uninfected and challenged controls, respectively. Groups 3 and 4 were weakly infected with increasing doses of Ascaris suum eggs and treated with pyrantel (Group 4). Groups 5-7 were immunized with 14, 42 and 97 kDa proteins from the parasite, respectively. Groups 2-7 were challenged with 10,000 infective eggs 7 days before the sacrifice. The focal parasitic granulomata with eosinophils and lymphocytes were the main histopathological lesions in the liver of reinfected pigs, while more marked cellular infiltrate and abundant connective tissue were seen in the livers of immunized animals. There were important deposits of antigens in the livers of immunized and infected pigs. Antigens were mainly located in the connective tissue, with positive staining detection of the somatic larvae antigen, the body wall from the adult worms and the 14-, 42- and 97-kDa proteins. However, cholangiols, biliary ducts and macrophages presented an immunohistochemical positive stain against excretory-secretory and somatic antigens from the larvae and the body fluid antigen from the adult parasite. The detection of A. suum antigens in the liver of infected pigs improves the diagnosis of swine ascariosis. It may be possible to apply these procedures for diagnosis of human ascariosis in liver biopsies since A. suum from swine have been previously used as a substitute for the study of the human parasite Ascaris lumbricoides.     

Induction of systemic and local basophil and eosinophil responses in guinea pigs by the feeding of the tsetse fly Glossina morsitans

Guinea pigs infested with Glossina morsitans weekly for 5 weeks exhibited marked peripheral blood basophil and eosinophil responses to each infestation, with a dominant cutaneous basophil response to challenge infestation. G. morsitans feeding was completed within 3--10 min, depending upon prior exposure, and flies were reluctant to feed and probed longer on hyperexposed animals. Blood basophil responses exhibited the greatest increases over controls (up to 12-fold) compared to eosinophils (up to 3-fold). After the first and third infestations, both basophil and eosinophil levels increased, whereas after the second and fourth infestations both cell types declined. Greatest blood basophil responses developed after the first infestation with levels ranging from 0 to 14 +/- 9 cells/mm3 in infested animals to 0 and 2 +/- 2 cells/mm3 in uninfested controls. Eosinophilia increased with each infestation where levels ranged from 57 +/- 23 cells/mm3 after the first tsetse feeding to 110 +/- 20 cells/mm3 after the fourth infestation; compared to 11 +/- 11 to 50 +/- 12 cells/mm3 in uninfested controls. Fly-feeding sites were marked by hemorrhages, and probing behavior resulted in a line of small hemorrhages when the underside of the skin was examined. Histologically, G. morsitans feeding sites in naive guinea pigs 24 h post-infestation were dominated by mononuclear cells (93% of the infiltrate) with a weak granulocyte component, of which eosinophils were dominant (1.3%). Tsetse feeding sites in guinea pigs exposed 3 times previously were again dominated by mononuclear cells (57% of the infiltrate), but granulocytes comprised a significant part of the response (43% of the infiltrate) where basophils were dominant (25%).     

仙游县高致病性猪蓝耳病强制免疫抗体的监测

为了解和掌握仙游县2015年高致病性猪蓝耳病免疫效果,对仙游县18个乡镇2015年春防和秋防期间已免高致病性猪蓝耳病疫苗的猪血液样品进行免疫抗体水平监测。共监测1535份血清,其中春季765份、秋季770份,免疫抗体合格率分别为96.6%、93.8%。结果表明仙游县高致病性猪蓝耳病免疫抗体水平较高,而集中监测是预防、控制PRRS发生和流行的有效方法。