After immunization of four calves with a live modified Mycobacterium paratuberculosis vaccine the course of the humoral and cell mediated immune reactions was studied during a 2-year clinical investigation. Furthermore, the possibility of shedding of the vaccine strain and the influence of the vaccination on the tuberculin skin test was determined. In addition to standard procedures recently developed diagnostic methods (antibody enzyme-linked immunosorbent assay, interferon-gamma test, polymerase chain reaction) were used. A cell-mediated immune reaction, reflected in an increased, specifically induced, interferon-gamma production developed much earlier (1-2 weeks post-immunization) than humoral immunity (8-16 weeks post-gamma immunization). While the increase in antibody titres was transient, declining to extremely low levels 48-60 weeks post-immunization, cell-mediated immunity remained detectable until the end of the investigation. Spread of the vaccine strain into the body and shedding were never detected during the whole course of the study except for one colon site in one calf. As late as 2 years after vaccine application positive or doubtful skin reactions against M. bovis purified protein derivative were measured, reflecting possible interference of the immunization with the diagnosis of bovine tuberculosis. At the end of the investigation, a positive cell-mediated immune reaction was detected the control animal although clinical, pathological and bacteriological examinations gave no indication for a mycobacterial infection.

A universal influenza vaccine must provide protection against antigenically divergent influenza viruses either through broadly neutralizing antibodies or cross-reactive T cells. Here, intranasal immunizations with recombinant adenoviral vectors (rAd) encoding hemagglutinin (HA) and nucleoprotein (NP) in combination with rAd-Interleukin-(IL)-1β or rAd-IL-18 were evaluated for their efficacy in BALB/c mice. Mucosal delivery of rAd-IL-1β enhanced HA-specific antibody responses including strain-specific neutralizing antibodies. Nevertheless, the beneficial effects on the local T cell responses were much more impressive reflected by increased numbers of CD103CD69 tissue-resident memory T cells (T). This increased immunogenicity translated into superior protection against infections with homologous and heterologous strains including H1N1, pH1N1, H3N2, and H7N7. Inhibition of the egress of circulating T cells out of the lymph nodes during the heterologous infection had no impact on the degree of protection underscoring the unique potential of T for the local containment of mucosal infections. The local co-expression of IL-1β and antigen lead to the activation of critical checkpoints in the formation of T including activation of epithelial cells, expression of chemokines and adhesion molecules, recruitment of lung-derived CD103 DCs, and finally local T imprinting. Given the importance of T-mediated protection at mucosal barriers, this study has major implications for vaccine development.

In the German state of Rhineland-Palatinate, herds were identified that were likely to have a Neospora caninum sero-prevalence > or = 10% by using a bulk milk ELISA. Individual herd data were obtained by a questionnaire. Univariate logistic regression showed that bulk milk positive farms had a significantly higher chance to report an increased abortion rate than negative farms (P(Wald)<0.1). The chance to have a bulk milk positive herd increased with the minimum number of years a farm had reported an increased abortion rate (P(Wald)<0.1). Questionnaire data, population and dog density as well as climatic data specific for the farm localization were used to identify potential risk factors for a herd to have acquired N. caninum infections. Within an optimized multiple logistic regression model 'Number of farm dogs', 'Herd size', and factors related to the municipality the farm was localized, i.e. 'Mean temperature in July', and 'Dog density' were significant risk factors (P(Wald)<0.1). The present study underlines the role farm dogs have in the epidemiology of neosporosis. In addition, it suggests that the risk a herd has to acquire N. caninum infections is also associated with factors related to the farm location, i.e. factors that are largely out of the control of farmers.

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In the present study, 132 selected faecal samples from clinically affected and subclinically infected cattle from dairy herds known to be affected by Johne's disease were investigated for the presence of Mycobacterium paratuberculosis using Ziehl-Neelsen staining, faecal culture and a commercially available DNAProbe ® test. The sensitivity was 36.4% for Ziehl-Neelsen staining, 85.6% for faecal culture and 47.7% for the DNA-Probe ® test. Proving the presence of acid-fast bacteria in 49.3% of the samples from clinically affected cattle and 19.3% of those from subclinically infected cattle, Ziehl-Neelsen staining had the lowest detection rate of the three tests under investigation. Faecal culture showed the highest detection rate of M. paratuberculosis in samples from both clinically affected (84.0%) and subclinically infected (87.7%) animals. The DNA-Probe ® test showed a positive result in 68.0% of the samples from clinically affected cattle and 21.1% of those from subclinically infected cattle. Ziehl-Neelsen staining proved unreliable in diagnosing Johne's disease. Faecal culture was the most sensitive method for detecting M. paratuberculosis both in clinically affected and subclinically infected cattle. The sensitivity of a commercially available DNAProbe ® test has to be enhanced to enable a quick and reliable diagnosis of Johne's disease.

The envelope protein (Env) is the only surface protein of the human immunodeficiency virus (HIV) and as such the exclusive target for protective antibody responses. Experimental evidences from mouse models suggest a modulating property of Env to steer antibody class switching towards the less effective antibody subclass IgG1 accompanied with strong TH2 helper responses. By simple physical linkage we were able to imprint this bias, exemplified by a low IgG2a/IgG1 ratio of antigen-specific antibodies, onto an unrelated antigen, namely the HIV capsid protein p24. Here, our results indicate the glycan moiety of Env as the responsible immune modulating activity. Firstly, in Card9−/− mice lacking specific C-Type lectin responsiveness, DNA immunization significantly increased the IgG2a/IgG1 ratio for the Env-specific antibodies while the antibody response against the F-protein of the respiratory syncytial virus (RSV) serving as control antigen remained unchanged. Secondly, sequential shortening of the Env encoding sequence revealed the C2V3 domain as responsible for the strong IgG1 responses and TH2 cytokine production. Removing all potential N-glycosylation sites from the C2V3 domain by site-specific mutagenesis reversed the vaccine-induced immune response towards a Th1-dominated T-cell response and a balanced IgG2a/IgG1 ratio. Accordingly, the stretch of oligomannose glycans in the C2V3 domain of Env might mediate a specific uptake and/or signaling modus in antigen presenting cells by involving interaction with an as yet unknown C-type lectin receptor. Our results contribute to a deeper understanding of the impact of Env glycosylation on HIV antigen-specific immune responses, which will further support HIV vaccine development.

For almost three decades, transmissible gastroenteritis virus (TGE), a coronavirus, was the only known viral agent to cause severe neonatal diarrhoea in pigs, giving rise to considerable losses (1). Recently, a number of other viruses have been shown to be involved in the aetiology of diarrhoea in pigs, namely rotaviruses (9, 1 l), the epizootic diarrhoea virus (another coronaviruslike agent not related to TGE virus,4,8,14), rotavirus-like, calici-virus-like and 23 nm virus-like particles (18). Present evidence suggests that in addition to TGE virus, rotaviruses and epizootic diarrhoea virus are widespread and of considerable economic importance. The clinical and epizootiological picture of infections with these three agents is similar (3, 5, 15) and differential diagnosis is difficult. Furthermore, histological findings in the small intestine, which is the target organ of these viruses, reveal remarkable similarities. Since the histological and ultrastructural changes of natural and experimental TGE and rotavirus infections are known from a number of studies (10, 12, 16, 17), it is of interest to investigate the pathological changes caused by epizootic diarrhoea virus and compare them with TGE and rotavirus infections. U. S. Copyright Clearance Center Code Statement: 0721-1 856/81/2807-0564$02.50/0 Light Microscopy and Ultrahistology of Intestinal Changes in Pigs Material and Methods 565 AnimalsSix naturally infected piglets (2 piglets 5-6 days, and 4 piglets 4-6 weeks old) and four piglets (2-5 days old) infected experimentally with an intestinal filtrate from a confirmed EVD field case were examined. The experimentally infected animals were sacrificed 20-24 hours and 36-48 hours after infection. Clinical and epizootiological data on the naturally infected piglets have been reported elsewhere (8).TGE lesions were studied in 5 naturally infected animals 3-9 days of age, and i n 2 newborn piglets experimentally infected with 1,000 LD 50 of an intestinal suspension from a piglet infected with the Miller strain. These piglets were sacrificed 48 hours after infection. Rotavirus infected intestines were obtained by infecting 2 piglets at 2 days of age with the field strain Munich V 1274 and harvesting the material 48 hours later. Four non-infected healthy animals at 2-4 days of age served as controls.The experimental piglets were colostrum-deprived and fed reconstituted dried cow milk supplemented with vitamins (Biofix-F, Milchhof, Munich). All infections were carried out orally. The animals were anaesthesized with Narcoren@, and jejunal tissues were taken from the cranial, middle and caudal parts. Colon tissue was sampled from the middle part. Regional lymph nodes were also investigated. Irnmunofluorescence staining (FA)Frozen sections were made from all intestinal samples for the demonstration of viral antigens by FA. The sections were fixed with acetone at 4 OC for 10 minutes and stained directly using EVD*-, TGE-, and rotavirus antibody FITC conjugates. HistologyAfter fixation in 7 O/o neutral formalin, paraffin ...

Characteristics of four transmissible gastroenteritis (TGE) virus field strains (Miller, Purdue, Bl, and V203) and four cell culture-attenuated strains (Purdue, SH, CKp, and Bl) were studied to find methods of differentiation between the two groups of viruses. TGE field virus strains did not replicate as well as attenuated strains at 37 C and could not be passaged serially for more than four to six passages at 33 C. There were clear differences in plaque size when the strains were compared. Field strains had average plaque sizes ranging from 3.59 to 3.15 mm, whereas attenuated strains induced plaques that were larger than 4.2 mm. Variations were observed in stability of strains at pH 3.0. Field strains and cell culture-attenuated strains CKp-270 and SH-114 were reduced in titer by about 1 log10. A reduction of about 3 log1o, however, was obtained with cell culture strains B1-300 and Purdue-113.