Correction: Schistosoma japonicum infection downregulates house dust mite-induced allergic airway inflammation in mice.

[This corrects the article DOI: 10.1371/journal.pone.0179565.].

Schistosoma japonicum infection downregulates house dust mite-induced allergic airway inflammation in mice.

The "hygiene hypothesis" is a theory try to explain the dramatic increases in the prevalence of autoimmune and allergic diseases over the past two to three decades in developed countries. According to this theory, reduced exposure to parasites and microorganisms in childhood is the main cause for the increased incidences of both T helper 1 (Th1)-mediated autoimmunity and Th2-mediated allergy. In this study, we investigated the impact of Schistosoma japonicum infection on the allergic airway inflammation induced by repeated intracheal inoculations of house dust mites (HDM), which is a Th17 and neutrophils dominant murine asthma model, mimicking severe asthma. We found that S. japonicum infection downregulated airway hyperresponsiveness. The infiltrating cells, Th17 and Th2 effector cytokines in the bronchoalveolar lavage (BAL) fluids and lungs were significantly reduced in the infected mice. Our findings indicated that S. japonicum infection was able to effectively inhibit host's allergic airway inflammation, which may be related to the upregulated Treg cells upon infection. To our knowledge, it is the first study to reveal the impact of S. japonicum infection on house dust mite induced severe asthma. More in depth investigation is need to elucidate the underlying mechanisms.

Fusion-expressed CTB improves both systemic and mucosal T-cell responses elicited by an intranasal DNA priming/intramuscular recombinant vaccinia boosting regimen.

Previous study showed that CTB (Cholera toxin subunit B) can be used as a genetic adjuvant to enhance the systemic immune responses. To further investigate whether it can also be used as a genetic adjuvant to improve mucosal immune responses, we constructed DNA and recombinant Tiantan vaccinia (rTTV) vaccines expressing OVA-CTB fusion antigen. Female C57BL/6 mice were immunized with an intranasal DNA priming/intramuscular rTTV boosting regimen. OVA specific T-cell responses were measured by IFN-γ ELISPOT and specific antibody responses were determined by ELISA. Compared to the nonadjuvant group (pSV-OVA intranasal priming/rTTV-OVA intramuscular boosting), pSV-OVA-CTB intranasal priming/rTTV-OVA-CTB intramuscular boosting group significantly improved the magnitudes of T-cell responses at spleen (1562 ± 567 SFCs/10(6) splenocytes versus 330 ± 182 SFCs/10(6) splenocytes, P < 0.01), mesenteric LN (96 ± 83 SFCs/10(6) lymphocytes versus 1 ± 2 SFCs/10(6) lymphocytes, P < 0.05), draining LNs of respiratory tract (109 ± 60 SFCs/10(6) lymphocytes versus 2 ± 2 SFCs/10(6) lymphocytes, P < 0.01) and female genital tract (89 ± 48 SFCs/10(6) lymphocytes versus 23 ± 21 SFCs/10(6) lymphocytes, P < 0.01). These results collectively demonstrated that fusion-expressed CTB could act as a potent adjuvant to improve both systemic and mucosal T-cell responses.

Boosting functional avidity of CD8+ T cells by vaccinia virus vaccination depends on intrinsic T-cell MyD88 expression but not the inflammatory milieu.

UNLABELLED: T-cell functional avidity is a crucial determinant for efficient pathogen clearance. Although recombinant DNA priming coupled with a vaccinia-vectored vaccine (VACV) boost has been widely used to mount robust CD8+ T-cell responses, how VACV boost shapes the properties of memory CD8+ T cells remains poorly defined. Here, we characterize the memory CD8+ T cells boosted by VACV and demonstrate that the intrinsic expression of MyD88 is critical for their high functional avidity. Independent of selection of clones with high-affinity T-cell receptor (TCR) or of enhanced proximal TCR signaling, the VACV boost significantly increased T-cell functional avidity through a decrease in the activation threshold. VACV-induced inflammatory milieu is not sufficient for this improvement, as simultaneous administration of the DNA vaccine and mock VACV had no effects on the functional avidity of memory CD8+ T cells. Furthermore, reciprocal adoptive transfer models revealed that the intrinsic MyD88 pathway is required for instructing the functional avidity of CD8+ T cells boosted by VACV. Taking these results together, the intrinsic MyD88 pathway is required for the high functional avidity of VACV-boosted CD8+ T cells independent of TCR selection or the VACV infection-induced MyD88-mediated inflammatory milieu. IMPORTANCE: Functional avidity is one of the crucial determinants of T-cell functionality. Interestingly, although it has been demonstrated that a DNA prime-VACV boost regimen elicits high levels of T-cell functional avidity, how VACV changes the low avidity of CD8+ T cells primed by DNA into higher ones in vivo is less defined. Here, we proved that the enhancement of CD8+ T cell avidity induced by VACV boost is mediated by the intrinsic MyD88 pathway but not the MyD88-mediated inflammatory milieu, which might provide prompts in vaccine design.

[Design, synthesis and antiasthmatic activities of NO-donating seratrodast derivatives].

AIM: To search for novel antiasthmatic agents. METHODS: Coupling seratrodast (SD), an antiasthmatic drug, with several different types of NO donors including oxatriazoles, N-hydroxyguanidines and furoxans; evaluating the antiasthmatic effects of coupled compounds by determining their inhibitory activity of guinea pig asthma induced by acetylcholine and histamine; and assessing NO releasing ability. RESULTS: Nine novel target compounds (I1-9) were synthesized, and their structures were established by IR, NMR, MS and elemental analysis. Preliminary pharmacological test showed that most of the compounds showed high antiasthmatic activities (the latent period of induced asthma was prolonged from 10 s (SD) to 26-62 s), among which 3 compounds (I4, I6, I7) were more potent than SD (P < 0.05, P < 0.01) and released more NO than others. The maximum concentrations (Cmax) of NO-release in vitro were 0.1878, 0.1393 and 0.2473 mg x L(-1), respectively. CONCLUSION: NO donating-SD derivatives are worthy to be futher investigated.