Membrane Vesicles Derived from Bordetella bronchiseptica: Active Constituent of a New Vaccine against Infections Caused by This Pathogen.

Bordetella bronchiseptica, a Gram-negative bacterium, causes chronic respiratory tract infections in a wide variety of mammalian hosts, including humans (albeit rarely). We recently designed Bordetella pertussis and Bordetella parapertussis experimental vaccines based on outer membrane vesicles (OMVs) derived from each pathogen, and we obtained protection against the respective infections in mice. Here, we demonstrated that OMVs derived from virulent-phase B. bronchiseptica (OMVBbvir+) protected mice against sublethal infections with different B. bronchiseptica strains, two isolated from farm animals and one isolated from a human patient. In all infections, we observed that the B. bronchiseptica loads were significantly reduced in the lungs of vaccinated animals; the lung-recovered CFU were decreased by ≥4 log units, compared with those detected in the lungs of nonimmunized animals (P < 0.001). In the OMVBbvir+-immunized mice, we detected IgG antibody titers against B. bronchiseptica whole-cell lysates, along with an immune serum having bacterial killing activity that both recognized B. bronchiseptica lipopolysaccharides and polypeptides such as GroEL and outer membrane protein C (OMPc) and demonstrated an essential protective capacity against B. bronchiseptica infection, as detected by passive in vivo transfer experiments. Stimulation of cultured splenocytes from immunized mice with OMVBbvir+ resulted in interleukin 5 (IL-5), gamma interferon (IFN-γ), and IL-17 production, indicating that the vesicles induced mixed Th2, Th1, and Th17 T-cell immune responses. We detected, by adoptive transfer assays, that spleen cells from OMVBbvir+-immunized mice also contributed to the observed protection against B. bronchiseptica infection. OMVs from avirulent-phase B. bronchiseptica and the resulting induced immune sera were also able to protect mice against B. bronchiseptica infection.IMPORTANCEBordetella bronchiseptica, a Gram-negative bacterium, causes chronic respiratory tract infections in a wide variety of mammalian hosts, including humans (albeit rarely). Several vaccines aimed at preventing B. bronchiseptica infection have been developed and used, but a safe effective vaccine is still needed. The significance and relevance of our research lie in the characterization of the OMVs derived from B. bronchiseptica as the source of a new experimental vaccine. We demonstrated here that our formulation based on OMVs derived from virulent-phase B. bronchiseptica (OMVBbvir+) was effective against infections caused by B. bronchiseptica isolates obtained from different hosts (farm animals and a human patient). In vitro and in vivo characterization of humoral and cellular immune responses induced by the OMVBbvir+ vaccine enabled a better understanding of the mechanism of protection necessary to control B. bronchiseptica infection. Here we also demonstrated that OMVs derived from B. bronchiseptica in the avirulent phase and the corresponding induced humoral immune response were able to protect mice from B. bronchiseptica infection. This realization provides the basis for the development of novel vaccines not only against the acute stages of the disease but also against stages of the disease or the infectious cycle in which avirulence factors could play a role.

Characterization of the immune response induced by pertussis OMVs-based vaccine.

For the development of a third generation of pertussis vaccine that could improve the control of the disease, it was proposed that the immune responses induced by the classic whole cell vaccine (wP) or after infection should be used as a reference point. We have recently identified a vaccine candidate based on outer membrane vesicles (OMVs) derived from the disease etiologic agent that have been shown to be safe and protective in mice model of infection. Here we characterized OMVs-mediated immunity and the safety of our new candidate. We also deepen the knowledge of the induced humoral response contribution in pertussis protection. Regarding the safety of the OMVs based vaccine (TdapOMVsBp,) the in vitro whole blood human assay here performed, showed that the low toxicity of OMVs-based vaccine previously detected in mice could be extended to human samples. Stimulation of splenocytes from immunized mice evidenced the presence of IFN-γ and IL-17-producing cells, indicated that OMVs induces both Th1 and Th17 response. Interestingly TdapOMVsBp-raised antibodies such as those induced by wP and commercial acellular vaccines (aP) which contribute to induce protection against Bordetella pertussis infection. As occurs with wP-induced antibodies, the TdapOMVsBp-induced serum antibodies efficiently opsonized B. pertussis. All the data here obtained shows that OMVs based vaccine is able to induce Th1/Th17 and Th2 mixed profile with robust humoral response involved in protection, positioning this candidate among the different possibilities to constitute the third generation of anti-pertussis vaccines.

Mechanisms contributing to the virus persistence in Aleutian disease.

In this review published results and further studies concerning the persistence of Aleutian disease virus (ADV) isolate SL3 are presented. By Southern blot and in situ hybridization with strand-specific RNA probes focal replication of ADV-DNA was demonstrated in spleen, mesenteric lymph nodes, sporadically in mononuclear cells of the peripheral blood and bone marrow cells. These findings further support the concept of the lymphotropism of ADV. All cell culture-adapted ADV strains appear to have a ts-defect. Our in vitro studies indicate that the ADV isolate G(orham) induced the synthesis of comparable amounts of viral replicative DNA and viral proteins VP1 and VP2 at the non-permissive temperature of 37 degrees C. However, the viral progeny DNA synthesis was about threefold less at 37 degrees C compared to the permissive temperature of 32 degrees C. These findings suggest that the reduced level of viral progeny DNA at 37 degrees C accounts for the reduced production of infectious ADV. Finally, we provided experimental evidence that the apparent lack of neutralizing antibodies in AD is due to the masking of critical viral epitopes by cellular phospholipids.

[Clinical, psychological, and psychophysiological characteristics of neurotic-functional, cardiovascular and neurotic-depressive syndromes]. / Klinische, testpsychologische und psychophysiologische Charakteristik neurotisch-funktioneller, kardiovaskulärer und neurotisch-depressiver Syndrome

A total of ninety women classified into three groups (with cardiovascular, depressive, and other principal symptoms) according to clinical criteria were characterized by clinico-anamnestic, psychological, and psychophysiological data with the goal of arriving at a practically oriented differentiation of neurotic syndromes. The relevant variables were determined by means of a factor analysis. The physiological reaction patterns determined in experiments on psychically strained individuals proved unsuitable for the differentiation of the two syndromes. The problems associated with a symptom-oriented classification are discussed.