Immunization with an Autotransporter Protein of Orientia tsutsugamushi Provides Protective Immunity against Scrub Typhus

BackgroundScrub typhus is an acute febrile disease caused by Orientia tsutsugamushi infection. Recently, the rapid increase of scrub typhus incidence in several countries within the endemic region has become a serious public health issue. Despite the wide range of preventative approaches that have been attempted in the past 70 years, all have failed to develop an effective prophylactic vaccine. Currently, the selection of the proper antigens is one of the critical barriers to generating cross-protective immunity against antigenically-variable strains of O. tsutsugamushi.Conclusions/SignificanceImmunization of ScaA proteins provides protective immunity in mice when challenged with the homologous strain and significantly enhanced protective immunity against infection with heterologous strains. To our knowledge, this is the most promising result of scrub typhus vaccination trials against infection of heterologous strains in mouse models thus far.     

Antimicrobial peptide scolopendrasin VII,derived from the centipede Scolopendra subspinipes mutilans,stimulates macrophage chemotaxis via formyl peptide receptor 1

In this study, we report that one of the antimicrobial peptides scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates actin polymerization and the subsequent chemotactic migration of macrophages through the activation of ERK and protein kinase B (Akt) activity. The scolopendrasin VII-induced chemotactic migration of macrophages is inhibited by the formyl peptide receptor 1 (FPR1) antagonist cyclosporine H. We also found that scolopendrasin VII stimulate the chemotactic migration of FPR1-transfected RBL-2H3 cells, but not that of vector-transfected cells; moreover, scolopendrasin VII directly binds to FPR1. Our findings therefore suggest that the antimicrobial peptide scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates macrophages, resulting in chemotactic migration via FPR1 signaling, and the peptide can be useful in the study of FPR1-related biological responses. [BMB Reports 2015; 48(8): 479-484]     

Reproduction and initial development of manybar goatfish <Emphasis Type="Italic">Parupeneus multifasciatus</Emphasis> (Mullidae)

Features of reproductive biology and the stages of early ontogeny are described in the mass tropical species manybar goatfish Parupeneus multifasciatus. In general, in the catches represented by mainly sexually mature fishes, females prevail but males prevail in the largest size classes. The females reach their first sexual maturity by approximately 110 mm fork length, and they are characterized by continuous oogenesis and egg deposition in batches. The fish spawn over the entire year with a trend to lower values of the gonadosomatic index (GSI) of the females from June to October. The features of early ontogeny are compared in manybar goatfish and red mullet Mullus barbatus ponticus from the Black Sea.     

The Guts of Herbivorous Invertebrates: Promising Sources of Diverse Microorganisms with Unique Hemicellulolytic Systems

Invertebrates including insects are heterotrophic organisms and widely distributed in ecosystems. Due to their superior ability to digest various types of plant biomass taken as foods, some herbivorous invertebrates have attracted a great deal of industrial attention because such organisms include diverse cellulolytic and hemicellulolytic symbionts in their gut. Recent studies have shown that some of gut microorganisms of herbivores possess one or more extracellular fibrolytic enzymes with unique functions, which can be exploited as useful biocatalysts in various bioindustrial fields. Specifically, microbial hemicellulases with favorable biocatalytic activities are expected to be used for the development of excellent animal feed additives, production of prebiotics such as xylo‐ and mannooligosaccharides, and pretreatment of lignocellulosic biomass for the preparation of fermentable sugars. Here, we review our recent studies accomplished on several hemicellulolytic bacteria isolated from the guts of invertebrates and their glycoside hydrolases such as endo‐β‐1,4‐xylanases and endo‐β‐1,4‐mannanases.     

Staphylococcus aureus Lpl protein triggers human host cell invasion via activation of Hsp90 receptor

Staphylococcus aureus is a facultative intracellular pathogen. Recently, it has been shown that the protein part of the lipoprotein‐like lipoproteins (Lpls), encoded by the lpl cluster comprising of 10 lpls paralogue genes, increases pathogenicity, delays the G2/M phase transition, and also triggers host cell invasion. Here, we show that a recombinant Lpl1 protein without the lipid moiety binds directly to the isoforms of the human heat shock proteins Hsp90α and Hsp90ß. Synthetic peptides covering the Lpl1 sequence caused a twofold to fivefold increase of S. aureus invasion in HaCaT cells. Antibodies against Hsp90 decrease S. aureus invasion in HaCaT cells and in primary human keratinocytes. Additionally, inhibition of ATPase function of Hsp90 or silencing Hsp90α expression by siRNA also decreased the S. aureus invasion in HaCaT cells. Although the Hsp90ß is constitutively expressed, the Hsp90α isoform is heat‐inducible and appears to play a major role in Lpl1 interaction. Pre‐incubation of HaCaT cells at 39°C increased both the Hsp90α expression and S. aureus invasion. Lpl1‐Hsp90 interaction induces F‐actin formation, thus, triggering an endocytosis‐like internalisation. Here, we uncovered a new host cell invasion principle on the basis of Lpl‐Hsp90 interaction.