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Background: We previously reported that prior nasal administration of highly attenuated Bordetella pertussis BPZE1 provides effective and sustained protection against lethal challenge with influenza A viruses. The protective effect was mediated by suppressing the production of major pro-inflammatory mediators. To further explore the anti-inflammatory properties of BPZE1, we investigated the effect of BPZE1 nasal pretreatment on two mouse models of allergic disease, allergic airway inflammation, and contact hypersensitivity (CHS)., Methods: Allergic reactions were induced in mice nasally pretreated with live attenuated BPZE1 bacteria using the ovalbumin (OVA)-induced allergic airway inflammation and dinitrochlorobenzene (DNCB)-induced CHS models., Results: Prior BPZE1 nasal treatment suppressed OVA-induced lung inflammation and inflammatory cell recruitment and significantly reduced IgE levels and cytokine production. Similarly, BPZE1 nasal pretreatment markedly inhibited ear swelling, skin inflammation, and production of pro-inflammatory cytokines in the DNCB-induced CHS model. For both models, we showed that BPZE1 pretreatment does not affect the sensitization phase. Upon challenge, BPZE1 pretreatment selectively reduced the level of cytokines whose production is increased and did not affect the basal level of other cytokines. Together, our observations suggest that BPZE1 pretreatment specifically targets those cytokine-producing effector cells that are recruited and involved in the inflammatory reaction., Conclusion: Our study demonstrates the broad anti-inflammatory properties of the attenuated B. pertussis BPZE1 vaccine candidate and supports its development as a promising agent to prevent and/or treat allergic diseases., (© 2012 John Wiley & Sons A/S.)

Current bone disease therapy with bone marrow-derived mesenchymal stromal cells (MSC) is hampered by low efficiency. Advanced allogeneic studies on well-established mouse genetic and disease models are hindered by difficulties in isolating murine MSC (mMSC). And mMSC prepared from different laboratories exhibit significant heterogeneity. Hence, this study aimed to identify and isolate a sub-population of mMSC at an early passage number with high osteogenic potential. Enrichment of mMSC was achieved by 1-hr silica incubation and negative selection. Approximately 96% of these cells synthesized osteocalcin after 28 days of osteogenic induction in vitro, and displayed a complete dynamic alteration of alkaline phosphatase (ALP) activity with increasing osteogenic maturation and strong mineralization. Moreover, the cells displayed uniform and stable surface molecular profile, long-term survival, fast proliferation in vitro with maintenance of normal karyotype and distinct immunological properties. CD73 was found to be expressed exclusively in osteogenesis but not in adipogenesis. These cells also retained high osteogenic potential upon allogeneic transplantation in an ectopic site by the detection of bone-specific ALP, osteopontin, osteocalcin and local mineralization as early as 12 days after implantation. Hence, these cells may provide a useful source for improving current strategies in bone regenerative therapy, and for characterizing markers defining the putative MSC population.

Viruses cause asthmatic exacerbations in schoolchildren. We tested the hypothesis that children who wheezed with viral respiratory tract infections secrete higher levels of the type 1 cytokine interferon-gamma (IFN-gamma) in the peripheral circulation than children who had never wheezed. Blood was taken from 13 children (eight atopic) with episodic wheeze and 11 controls. CD4 and CD8 cells were separated from peripheral blood mononuclear cells and stimulated with phorbol 12-myrisate 13-acetate (PMA) and ionomycin for 24 h. IFN-gamma, IL-4, and IL-5 were measured in the supernatant by ELISA. IFN-gamma production by CD4 and CD8 cells was lower in children with a history of wheeze (CD4, P = 0.046; CD8, P = 0.037). These children were then analysed according to atopic status. CD4 and CD8 IFN-gamma production in nonatopic wheezy children was reduced (CD4, P=0.009; CD8, P=0.003). IFN-gamma production by atopic wheezy children was lower than by controls, but the differences were not significant (CD4, P = 0.2831; CD8, P = 0.1372). CD8 IL-5 was lower in children who wheezed (P=0.012). Release of IL-4 and IL-5 by CD4 cells did not differ between the three groups. We propose that defective IFN-gamma secretion by CD4 and CD8 cells may contribute to viral-induced wheeze in nonatopic children.

The link between immunoglobulin E (IgE) antibodies and environmental allergens, allergic sensitization and atopic diseases such as asthma, rhinitis and eczema is well established, yet treatment of these diseases is largely symptomatic and fails to correct the underlying immune disorder. B-cell production of IgE depends on interleukin 4 (IL-4) and is inhibited by interferon (IFN-gamma). These cytokines are produced by T-helper 2 (Th2) and T-helper 1 (Th1) CD4+ T cells respectively. In atopic dermatitis skin and asthmatic lung, Th2 cells predominate but antigen-specific CD4+ T-cell clones derived from peripheral blood are a mixture of Th1, Th2, and Th0. Circulating allergen-specific CD4+ T cells differentiate into Th1- and Th2-like clones in the presence of IL-12 and IL-4 respectively. In rats, CD8+ T cells are potent regulators of IgE responses in vivo, although the mechanism for this is still unclear. CD8+ T-cell depletion in immunized animals prolonged the IgE response but prior depletion did not. Indeed, prior depletion of CD8+ T cells actually inhibited IgE production, suggesting that there may be more than one type of IgE regulatory CD8+ T cell. This was supported by the observation that CD8+ T cells inhibited the differentiation of both Th1 and Th2 CD4+ T cells in vitro as well as IL-4- but not IL-2-induced Th2 CD4+ T-cell growth. The existence of distinct CD8+ T-cell subsets is supported by the observation that IL-4 and IFN-gamma regulate the growth and differentiation of CD8+ T cells.(ABSTRACT TRUNCATED AT 250 WORDS)

ELISA is increasingly used to measure antibodies in new circumstances. Recently, it has been applied to the measurement of IgG subclass antibodies against common antigens in early childhood. These studies have raised concerns about the specificity of some of these assays. This paper details the results of experiments which have assessed the specificity of IgG1 binding to allergens of dust mite (Dermatophagoides pteronyssinus) and ryegrass (Lolium perenne) pollen by inhibition ELISA in the sera of 2-year-old children of atopic parents. Six sera which showed binding of IgG1 to D. pteronyssinus and six to L. perenne were used. All had IgG1 antibody against ovalbumin. In the children's sera, binding to D. pteronyssinus was substantially inhibited by preincubation with the homologous antigen, but not with ovalbumin, thereby confirming the specificity of the assay. However, suppression of IgG1 binding to L. perenne with the homologous antigen was comparatively small, and ovalbumin could cause an equivalent inhibition, indicating poor specificity. Furthermore, the level of IgG1 binding to L. perenne was closely correlated to the level of IgG1 binding to ovalbumin (r = 0.98; P < 0.001). When the assay was reversed, IgG1 binding to ovalbumin was only slightly inhibited by L. perenne, indicating that most antibody binding to ovalbumin was specific. Thus, binding IgG1 in both adult and child sera to D. pteronyssinus appeared to be specific, while child, but not adult, IgG1 binding to L. perenne showed poor specificity. This disparity may be due to differences in the affinities of the respective antibodies, and it illustrates the importance of determining assay specificity when making measurements in early childhood.