127 research outputs found
Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza
The ectodomain of matrix protein 2 (M2e) of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs) have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored.A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs.The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections
Search for decays to invisible final states at Belle
We report the result from the first search for decays to invisible
final states. The analysis is performed on a data sample of 924
collected at and near the and resonances with the
Belle detector at the KEKB asymmetric-energy collider. The
absolute branching fraction is determined using an inclusive sample,
obtained by fully reconstructing the rest of the particle system including the
other charmed particle. No significant signal yield is observed and an upper
limit of is set on the branching fraction of to
invisible final states at 90\% confidence level.Comment: 17 pages, 4 figures, submitted to PRD(RC
Search for violation in the decay at Belle
We search for violation in the charged charm meson decay
, based on a data sample corresponding to an integrated
luminosity of collected by the Belle experiment at the KEKB
asymmetric-energy collider. The measured violating asymmetry
is , which is consistent with
the standard model prediction and has a significantly improved precision
compared to previous results.Comment: 8 pages, 3 figure
First Observation of Doubly Cabibbo-Suppressed Decay of a Charmed Baryon:
We report the first observation of the decay using a 980 data sample collected by the
Belle detector at the KEKB asymmetric-energy collider. This is the
first doubly Cabibbo-suppressed decay of a charmed baryon to be observed. We
measure the branching ratio of this decay with respect to its Cabibbo-favored
counterpart to be , where the uncertainties are
statistical and systematic, respectively.Comment: 6 pages, 3 figure
Evidence for Isospin Violation and Measurement of Asymmetries in
We report the first evidence for isospin violation in and
the first measurement of difference of asymmetries between and . This analysis is based on the data sample
containing pairs that was collected with the Belle
detector at the KEKB energy-asymmetric collider. We find evidence for
the isospin violation with a significance of 3.1, \%, where
the third uncertainty is due to the uncertainty on the fraction of to
production in decays. The measured value is
consistent with predictions of the SM. The result for the difference of
asymmetries is \%, consistent with zero. The measured branching fractions and
asymmetries for charged and neutral meson decays are the most precise to
date. We also calculate the ratio of branching fractions of to .Comment: 11 pages, 7 figures. shown at FPCP2017. accepted by PR
Search for decays with semileptonic tagging at Belle
We present the results of a search for the rare decays , where stands for and . The results are
obtained with pairs collected with the Belle
detector at the KEKB collider. We reconstruct one meson in a
semileptonic decay and require a single meson but nothing else on the
signal side. We observe no significant signal and set upper limits on the
branching fractions. The limits set on the , , , ,
, and channels
are the world's most stringent.Comment: Submitted to PR
Search for a dark vector gauge boson decaying to using decays
We report a search for a dark vector gauge boson that couples to
quarks in the decay chain , . No signal is found and we set a
mass-dependent limit on the baryonic fine structure constant of in the mass range of 290 to 520 MeV/. This analysis is
based on a data sample of 976 fb collected by the Belle experiment at
the KEKB asymmetric-energy collider.Comment: 6 pages, 4 figure
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