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Pathogen Interface (pathogen + interface)

Distribution by Scientific Domains

Life Sciences	60%

Selected Abstracts

Host-derived media used as a predictor for low abundant, in planta metabolite production from necrotrophic fungi

JOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2006
D.P. Overy
Abstract Aims:,Penicillium ser. Corymbifera strains were assayed on a variety of media and from infected Allium cepa tissues to evaluate the stimulation and in planta prediction of low abundance metabolites. Methods and Results:, Stimulated production of corymbiferones and the corymbiferan lactones were observed for Penicillium albocoremium, Penicillium allii, Penicillium hirsutum, Penicillium hordei and Penicillium venetum strains cultured on tissue media. Target metabolites were sporadically detected from strains cultured on common laboratory media (CYA, MEA and YES). Up to a 376 times increase in corymbiferone and corymbiferan lactone production was observed when culture extracts from CYA and A. cepa agar were compared by high pressure liquid chromatography with ultraviolet and mass spectrometry (LC-UV-MS). The novel metabolite corymbiferone B was purified and structure elucidated from a P. allii/A. cepa tissue medium extract. In planta expression of low abundance, target metabolites were confirmed from infected A. cepa tissue extracts by LC-UV-MS. Conclusions:, Secondary metabolite production was directly dependent and influenced by media conditions, resulting in the stimulated production of low abundance metabolites on host-derived media. Significance and Impact of the Study:, The use of macerated host tissue media can be applied in vitro to predict in planta expression of low abundance metabolites and aid in metabolite origin annotation during in planta metabolomic investigations at the host/pathogen interface. [source]

Pyrosequencing and characterization of immune response genes from the American dog tick, Dermacentor variabilis (L.)

INSECT MOLECULAR BIOLOGY, Issue 5 2010
D. C. Jaworski
Abstract Ticks continue to be a threat to animal and human health, and new and novel control strategies are needed for ticks and tick-borne pathogens. The characterization of the tick,pathogen interface and the tick immune response to microbial infections is fundamental toward the formulation of new control strategies for ticks and the pathogens they transmit. Our overall hypothesis for this research is that the tick immune system manages the maintenance of pathogens. Therefore, discovery of tick immune response genes may provide targets for novel control strategies directed toward reducing vector competency and pathogen transmission. In these studies, 454 pyrosequencing, a high-throughput genomic sequencing method was used to discover tick genes expressed in response to bacterial and fungal infections. Expressed sequence tags (ESTs) were analysed from Dermacentor variabilis ticks that had been injected with bacteria (Escherichia coli, Bacillus subtilis, Micrococcus luteus) or fungi (Saccharomyces cerevisiae and Candida albicans) and ticks that were naturally infected with the intracellular bacterium, Anaplasma marginale. By this approach, ESTs were assembled into 5995 contigs. Contigs fell into the five main functional categories of metabolism, genetic information processing, environmental information processing, cellular processes and human diseases. We identified more than 30 genes that are likely to encode for proteins involved in tick immune function. We further analysed by reverse transcriptase PCR (RT-PCR) the expression of 22 of these genes in each of our bacterial or fungal treatment groups and found that seven were up-regulated. Up-regulation of these seven genes was confirmed for bacterial, but not fungal treatment by quantitative PCR (qPCR). One of these products was novel, encoding a new tick defensin. Our results clearly demonstrate the complexities of the tick immune system and mark new directions for further study and characterization of proteins that modulate microbial infections in the American dog tick. [source]

Crystallization of recombinant Haemophilus influenzaee (P4) acid phosphatase

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2006
Zhonghui Ou
Haemophilus influenzae infects the upper respiratory tract of humans and can cause infections of the middle ear, sinuses and bronchi. The virulence of the pathogen is thought to involve a group of surface-localized macromolecular components that mediate interactions at the host,pathogen interface. One of these components is lipoprotein e (P4), which is a class C acid phosphatase and a potential vaccine candidate for nontypeable H. influenzae infections. This paper reports the crystallization of recombinant e (P4) and the acquisition of a 1.7,Å resolution native X-ray diffraction data set. The space group is P42212, with unit-cell parameters a = 65.6, c = 101.4,Å, one protein molecule per asymmetric unit and 37% solvent content. This is the first report of the crystallization of a class C acid phosphatase. [source]

Enemy at the gates: traffic at the plant cell pathogen interface

CELLULAR MICROBIOLOGY, Issue 12 2008
Caroline Hoefle
Summary The plant apoplast constitutes a space for early recognition of potentially harmful non-self. Basal pathogen recognition operates via dynamic sensing of conserved microbial patterns by pattern recognition receptors or of elicitor-active molecules released from plant cell walls during infection. Recognition elicits defence reactions depending on cellular export via SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex-mediated vesicle fusion or plasma membrane transporter activity. Lipid rafts appear also involved in focusing immunity-associated proteins to the site of pathogen contact. Simultaneously, pathogen effectors target recognition, apoplastic host proteins and transport for cell wall-associated defence. This microreview highlights most recent reports on the arms race for plant disease and immunity at the cell surface. [source]

Mammalian Toll-like receptors: to immunity and beyond

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2005
P. A. Hopkins
Summary Toll-like receptors (TLRs) constitute an archetypal pattern recognition system. Their sophisticated biology underpins the ability of innate immunity to discriminate between highly diverse microbial pathogens and self. However, the remarkable progress made in describing this biology has also revealed new immunological systems and processes previously hidden to investigators. In particular, TLRs appear to have a fundamental role in the generation of clonal adaptive immune responses, non-infectious disease pathogenesis and even in the maintenance of normal mammalian homeostasis. Although an understanding of TLRs has answered some fundamental questions at the host,pathogen interface, further issues, particularly regarding therapeutic modulation of these receptors, have yet to be resolved. [source]