Pathogen-produced catalase affects immune priming: A potential pathogen strategy.

Immune priming in invertebrates occurs when the first contact with a pathogen/parasite enhances resistance after a second encounter with the same strain or species. Although the mechanisms are not well understood, there is evidence that priming the immune response of some hosts leads to greater pro-oxidant production. Parasites, in turn, might counteract the host attack with antioxidants.

The occurrence of immune priming can be species-specific in entomopathogens.

Immune priming in invertebrates refers to an improved immune response (and therefore a better chance of survival) upon a second encounter with a specific pathogen. Although the existence of immune priming has been evaluated in invertebrate hosts, the ability of a particular entomopathogen species or strain to influence the occurrence of immune priming has not been thoroughly evaluated. The aim of the current study was to compare the occurrence of immune priming in Tenebrio molitor larvae after homologous challenges (a dual exposure to similar entomopathogens) with Serratia marcescens, Bacillus thuringiensis and Metarhizium anisopliae.

Identification of the transcription factor Znc1p, which regulates the yeast-to-hypha transition in the dimorphic yeast Yarrowia lipolytica.

The dimorphic yeast Yarrowia lipolytica is used as a model to study fungal differentiation because it grows as yeast-like cells or forms hyphal cells in response to changes in environmental conditions. Here, we report the isolation and characterization of a gene, ZNC1, involved in the dimorphic transition in Y. lipolytica.

Isolation, characterization and expression analysis of the ornithine decarboxylase gene (ODC1) of the entomopathogenic fungus, Metarhizium anisopliae.

The gene ODC1, which codes for the ornithine decarboxylase enzyme, was isolated from the entomopathogenic fungus, Metarhizium anisopliae. The deduced amino acid sequence predicted a protein of 447 amino acids with a molecular weight of 49.3 kDa that contained the canonical motifs of ornithine decarboxylases.

Expression of inducible nitric oxide synthase mRNA and nitric oxide production during the development of liver abscess in hamster inoculated with Entamoeba histolytica.

The present study analyzed iNOS and eNOS mRNA expression and NO production during development of hepatic abscess caused by Entamoeba histolytica trophozoites. One 374-bp sequence, which displayed 88% identity to mammalian iNOS protein, was isolated from LPS-stimulated peritoneal hamster macrophages. A separate 365-bp cDNA sequence showed 99% identity with eNOS protein.

The small GTP-binding protein Rho is expressed differentially during spore germination of Phycomyces blakesleeanus.

Evidence has been obtained for the presence of the small 22 kDa GTP-binding Rho protein in dormant spores of Phycomyces blakesleeanus. Immunoblotting with a polyclonal antibody against RhoA revealed a soluble and membrane-associated 22 kDa protein. When [32P]ADP-ribosylated by Clostridium botulinum C3 exotoxin the protein had a pI of 5.