No association of CTLA-4 polymorphisms with susceptibility to Behcet disease

Background: Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is a key negative regulator of T lymphocytes and has been shown to be associated with a number of autoimmune diseases. The present study was performed to assess the association between CTLA-4 polymorphisms and Behcet disease (BD) in Chinese patients. Methods: Two hundred and twenty-eight BD patients and 207 controls were analysed for four single nucleotide polymorphisms (SNPs) (21661A/G, 2318C/T, + 49G/A and CT60G/A) in the CTLA-4 gene by PCR-restriction fragment length polymorphism (RFLP) analysis. The association between SNP +49A/G and BD in Chinese population as well as other ethnic groups was analysed by meta-analysis. Results: No association could be detected between CTLA-4 SNPs or haplotypes and BD. Also, no association was observed between CTLA-4 polymorphisms and BD subgroups, stratified by clinical features. A meta-analysis showed that there was no heterogeneity between studies (p = 0.60, I-2 = 0%) and that CTLA-4 SNP + 49 was not associated with BD (overall effect: Z = 0.26, p = 0.79). Conclusion: This study and a meta-analysis failed to demonstrate any association between the tested CTLA-4 polymorphisms and B

Prevention and treatment of parasitic infections in organic pigs

Organic and free range pigs are potentially exposed to a wider range of parasites and zoonotic challenges. The livestock Subproject QLIF addresses 4 strategies to combat these challenges, and the present paper describes the initial results. Rodent control is the first strategy, and a survey concludes that Salmonella and Campylobacter infections were encountered in house mice and Norway rats, but not in other species. T. gondii antibodies could be detected in 6.4% of the blood samples taken from 235 wild small mammals. To reduce the presence of rodents around farms, the use of live-traps may be a good alternative for the use of rodenticides on organic farms. A second strategy is aimed at directing pig dunging behaviour in such a way that contact with (infected) faeces is minimised. The study showed that a rooting area resulted in a cleaner outdoor are and an extra outdoor drinker led to a cleaner area around the drinker, but to a dirtier indoor area. However, no difference in Ascaris suum infection were found. The nutritional strategy tested showed that pure inulin appeared the most effective as Oesophagostomum dentatum presence was reduced by 91%. Finally, as part of Strategy 4, a mixture of dried Thymus vulgaris, Melissa officinalis and Echinacea purpurea in a dosage of 5% in the diet showed to be preventive against a mild round-worm infection. The same mixture, however, was not effective in a lower dosage (3% in the diet) against a serious round-worm infection. Work is continuing to develop the above strategies further

Splenic CD8(+) T cells secrete TGF-beta 1 to exert suppression in mice with anterior chamber-associated immune deviation

Background CD8(+) regulatory T cells (Treg) have been considered to be involved in a model of ocular-induced tolerance, known as anterior chamber-associated immune deviation (ACAID). The mechanisms of suppression by CD8(+) T cells in ACAID remain only poorly understood. TGF-beta 1 is considered as an inhibitory cytokine for immunosuppression in some models. The production of TGF-beta 1 by CD8(+) T cells in ACAID, and whether CD8+ T cells exert suppression through TGF-beta 1, is unknown. Methods The suppressive effect of CD8(+) T cells in ACAID mice was determined by a local adoptive transfer (LAT) assay. The production of TGF-beta 1 by CD8(+) T cells was measured by enzyme-linked immunosorbent assay (ELISA). Anti-TGF-beta 1 antibodies were used in the LAT assay to test if they could block the inhibitory effect of CD8(+) T cells. Results CD8(+) T cells from ACAID mice were shown to block the delayed-type hypersensitivity (DTH) response in an antigen-specific manner in a LAT assay. These CD8+ T cells secreted TGF-beta 1, and their suppression could partially be blocked by anti-TGF-beta 1 antibodies. Conclusions Our study confirms that CD8+ T cells from ACAID mice possess inhibitory properties. This population exerts part of its suppressive function via the production of TGF-beta 1

Retinal S-antigen Th1 cell epitope mapping in patients with Behcet's disease

Background - Retinal S-antigen (S-Ag) is a most characterized autoantigen of autoimmune uveitis. The recognized immunodominant epitope of human S-Ag in patients with uveitis has not been identified. In this study, we selected certain patients with active uveitis to map the Th1 cell epitope spectrum of human S-Ag in Behcet's disease(BD). Methods - Blood samples were taken from eight active BD patients who showed an immune response to 40 mixed overlapping peptides spanning the entire sequence of human S-Ag. Peripheral blood mononuclear cells were isolated and stimulated with single S-Ag peptide at 5 mu g/ml or 20 mu g/ml. Single-cell immune responses were measured by IFN-gamma ELIspot assay. Results - BD patients heterogeneously responded to the S-Ag peptides at two concentrations. In general, the responses to 5 mu g/ml peptides were slightly stronger than those to 20 mu g/ml peptides, while the maximum SFC frequency to single peptide at the two concentrations was similar. Several peptides including P31, P35 and P40 induced a prominent response, with the frequency of S-Ag specific cells being about 0.007%. Significant reactivity pattern shift was noted in patients with different disease courses. Conclusions - Certain active BD patients have S-Ag specific Th1 cells with a low frequency. The S-Ag epitope specificity between patients is highly heterogeneous, and varies with the uveitis cours

Paratuberculose in de biologische melkveehouderij; omvang en gehanteerde management maatregelen omtrent paratuberculose

Paratuberculose leidt niet alleen tot zieke dieren en een verminderde melkproductie. Er zijn ook aanwijzingen dat de paratbc bacterie mogelijk een rol speelt bij bepaalde darmontstekingen bij de mens (de ziekte van Crohn). De rol die de bedrijfsvoering op het voorkomen van paratuberculose in de biologische melkveehouderij heeft is nog niet bekend en was het onderwerp van een onderzoek dat door de Animal Sciences Group in samenwerking met de Gezondheidsdienst voor Dieren (GD) is uitgevoerd. Bij 83 biologische melkveehouders is tijdens een bedrijfsbezoek een enquête afgenomen gericht op het in kaart brengen van mogelijke risicofactoren bij de insleep en versleep van paratbc. De resultaten van de enquête zijn omgerekend naar de zogenaamde ParaWijzer score en vergeleken met de scores van reguliere bedrijven. Biologische melkveehouders scoorden op een aantal factoren slechter dan gangbare veehouders. Om een beeld te krijgen van de omvang van paratbc in de biologische melkveehouderij is op 76 bedrijven bloedonderzoek gedaan bij de runderen van 3 jaar en ouder. Ook deze cijfers zijn vergeleken met door de GD verzamelde cijfers van gangbare veehouders. Uit analyse blijkt dat er geen wezenlijk verschil bestaat. Geconcludeerd kan worden dat in dit onderzoek de paratbc-situatie op de biologische bedrijven niet ongunstig is als we dit vergelijken met die van de reguliere melkveebedrijven in een vergelijkbaar onderzoek. De bedrijfsvoering houdt echter wel een groter risico in op de verspreiding van paratbc binnen het bedrijf als de infectie aanwezig is. Het is daarom van belang de ontwikkeling van paratbc binnen de biologische melkveehouderij te volgen om op tijd maatregelen te kunnen treffen als het besmettingsgevaar onverhoopt mocht stijgen

OVA-specific CD8(+)T cells do not express granzyme B during anterior chamber associated immune deviation

To examine antigen (Ag)-specific CTL response during anterior chamber associated immune deviation (ACAID). Methods OVA or OVA257-264 peptide was injected into the anterior chamber (AC) of C57BL/6 mice. There were 16 mice in each ACAID group induced with OVA or OVA257-264 peptide. The mice were primed by SC injection with OVA or OVA 257-264 peptide in complete Freund¿s adjuvant (CFA) on day 7. Ag-specific CD8+T cells in spleens were analyzed on day 14 using Pentamer H-2Kb-SIINFEKL(OVA257-264 peptide). IFN-¿ ELISPOT and intracellular granzyme B staining were used to characterize the CTL response. Twelve mice in each group immunized with OVA or OVA257-264 peptide in CFA served as positive controls. Twelve normal mice served as negative controls and 12 receiving injection of CFA as CFA controls for studying the influence of CFA on the Ag-specific CTL response. Result The results showed that anterior chamber inoculation of OVA or OVA257-264 peptide could induce ACAID as evidenced by an impaired DTH response. The frequency of Ag-specific CD8+T cells in ACAID mice was not different from that in mice challenged with Ags in CFA only (positive controls). IFN-¿ production by these cells in ACAID mice was not different compared to positive controls. However, Ag-specific CD8+T cells in ACAID mice failed to secrete granzyme B. Mice challenged only with OVA peptide and CFA also showed a granzyme B negative CD8+T cell response. Ag-specific CTL response induced by CFA alone was similar with the negative contro

Vaccines against toxoplasma gondii : challenges and opportunities

Development of vaccines against Toxoplasma gondii infection in humans is of high priority, given the high burden of disease in some areas of the world like South America, and the lack of effective drugs with few adverse effects. Rodent models have been used in research on vaccines against T. gondii over the past decades. However, regardless of the vaccine construct, the vaccines have not been able to induce protective immunity when the organism is challenged with T. gondii, either directly or via a vector. Only a few live, attenuated T. gondii strains used for immunization have been able to confer protective immunity, which is measured by a lack of tissue cysts after challenge. Furthermore, challenge with low virulence strains, especially strains with genotype II, will probably be insufficient to provide protection against the more virulent T. gondii strains, such as those with genotypes I or II, or those genotypes from South America not belonging to genotype I, II or III. Future studies should use animal models besides rodents, and challenges should be performed with at least one genotype II T. gondii and one of the more virulent genotypes. Endpoints like maternal-foetal transmission and prevention of eye disease are important in addition to the traditional endpoint of survival or reduction in numbers of brain cysts after challenge

AAV2-Mediated Combined Subretinal Delivery of IFN-α and IL-4 Reduces the Severity of Experimental Autoimmune Uveoretinitis

We previously showed that adeno-associated virus 2 (AAV2) mediated subretinal delivery of human interferon-alpha (IFN-α) could effectively inhibit experimental autoimmune uveoretinitis (EAU). In this study we investigated whether subretinal injection of both AVV2.IFN-α and AAV2.IL-4 had a stronger inhibition on EAU activity. B10RIII mice were subretinally injected with AAV2.IFN-α alone (1.5×107 vg), AAV2.IL-4 alone (3.55×107 vg), and AAV2.IFN-α combined with AAV2.IL-4. PBS, AAV2 vector encoding green fluorescent protein (AAV2.GFP) (5×107 vg) was subretinally injected as a control. IFN-α and IL-4 were effectively expressed in the eyes from three weeks to three months following subretinal injection of AAV2 vectors either alone or following combined administration and significantly attenuated EAU activity clinically and histopathologically. AAV2.IL-4 showed a better therapeutic effect as compared to AAV2.IFN-α. The combination of AAV2.IL-4 and AAV2.IFN-α was not significantly different as compared to AAV2.IL-4 alone. There was no difference concerning DTH (delayed-type hypersensitivity) reaction, lymphocyte proliferation and IL-17 production among the investigated treatment groups, suggesting that local retinal gene delivery did not affect the systemic immune response