Granulocytes of sea anemone Actinia equina (Linnaeus, 1758) body fluid contain and release cytolysins forming plaques of lysis

The Cnidaria phylum includes organisms that are among the most poisonous animals. The exact composition of cnidarian bioactive molecules is not known in detail, but little is known on the cells that produce the toxins. Here we have shown that the presence of cytolysins is not exclusive of nematocysts. A plaque-forming assay was carried out with cell populations extracted from the percoled body fluid showed for the first time that anthozoan granulocytes are able to form plaque of lysis. We have partitioned the total population of free cells into three distinct discrete bands by discontinuous Percoll gradient, and we have identified six small different types cells: morular granulocytes; cells with large or small peripherical granules, granulocytes with irregular shape containing blue and red granules, cells showing one fine red granule of uniform size and, finally, cells with elongated shape and small dispersed granules. Cell lysate of each cellular band resulted cytolytic toward different erythrocytes types. SDS page analysis of the lysate cell fraction showed a predominant of 20 kDa that corresponds to the weight of the cytolytic equinatoxin. The nature of equinatoxins-related activity was demonstrated by inhibition experiments using bovine sphingomyelin

Sea bass Dicentrarchus labrax (L.) bacterial infection and confinement stress acts on F-type lectin (DlFBL) serum modulation

The F-lectin, a fucose-binding protein found from invertebrates to ectothermic vertebrates, is the last lectin family to be discovered. Here, we describe effects of two different types of stressors, bacterial infection and confinement stress, on the modulation of European sea bass Dicentrarchus labrax (L.) F-lectin (DlFBL), a well-characterized serum opsonin, using a specific antibody. The infection of the Vibrio alginolyticus bacterial strain increased the total haemagglutinating activity during the 16-day testing period. The DlFBL value showed an upward regulation on the first, second and last days and underwent a slight downward regulation 4days post-challenge. In contrast, the effect of confinement and density stress showed a decrease in the plasma concentration of lectin, ranging from 50% to 60% compared with the control. The modulation of DlFBL is in line with the hypothesis that humoral lectins could be involved and recruited in the initial recognition step of the inflammation, which leads to agglutination, and the activation of mechanisms responsible for killing of the pathogens

Cold-active molecules for a sustainable preservation and restoration of historic-artistic manufacts

In the last decades biotechnology research provides sustainable alternatives to traditional procedures for preventive preservation of cultural assets. Recently, bioactive molecules (BMs) isolated from marine invertebrate organisms have been isolated and tested for bioremoval of protein layers (BMP) or to controlling microbial colonization (BMA), acting at temperature lower than 30°C. The Protease or Antimicrobial activity was tested on ad hoc assembled specimens and on different historic-artistic manufacts. In bio-removing protocol BMP molecules were applied as gelled solutions, in order to guarantees a selective action, respectful of constitutive materials and manufact integrity. Peculiarity of Protease bioactive molecules is the temperature of action, lower than 30°C. Instead, BMAs molecules have been tested to control bacteria and fungi colonization in laboratory specimens. In our hypothesis these novel molecules provide an important contribution to the development of innovative protocols safe both for the environment and conservator health, representing a valid alternative to traditional methods according to the preventive conservation and "Minimal Intervention" concept in restoration procedures

Invertebrate Models in Innate Immunity and Tissue Remodeling Research

Abstract is not provided for the editoria

Identification, cloning and environmental factors modulation of a ab defensin from the Lessepsian invasive mussel Brachidontes pharaonis (Bivalvia: Mytilidae).

Immunological effectors of invasive species playing a role in addressing new colonization are still poorly studied. In the present study the cDNA sequence of the defensin from a Lessepsian invasive species, the Red Sea mussel Brachidontes pharaonis, was cloned using RACE method. Defensins are a class of widely known antimicrobial peptides (AMPs), oligopeptides with a broad spectrum of targeted organisms ranging from viruses to parasites. Analysis of BpDef sequence (262 bp) revealed the presence of an ORF coding for 81 amino acids. The full-length amino acid sequence showed the highest similarity to antimicrobial peptides MGD1 and MGD2 sequence from Mytilus galloprovincialis. Phylogenetic analysis suggested that BpDef belongs to the αβ defensin AMPs with a typical domain structurally characterized by a α helix and two β sheets. BpDef mRNA is located in circulating hemocytes with small intra-cytoplasmic granules and with large granules. The transcription of defensin gene was modulated by the stress from temperatures and oxygenation condition. Temperatures of 20 °C did not stimulate a BpDef transcription over a short time. At 30 °C the kinetics of BpDef gene transcription showed up regulation after one day, while it was down regulated after six days, both under normoxia and hypoxia conditions

Molluscan antimicrobial peptides, a review from activity-based evidences to computer-assisted sequences

Antimicrobial peptides (AMPs) represent the most universal immune effectors. Molluscs constitute the second largest animal phylum, after Arthropods, in term of number of species. Only a negligible number has been investigated regarding AMPs. The choice of the species to be studied relied on their economical importance and availability. First studies on molluscan AMPs dated from 1996 and were based on biological activities of biochemical-purified fractions. Such approach released all the original structures we know, with biological activity sometimes different from one isoform to another. Then, molecular biology techniques were applied to molluscan AMPs starting in 1999. Complete screening of genome expression in various situations became available, as well as some exotic Molluscs, the ones collected from deep-sea hydrothermal vent, for instance. Full sequences of active peptides and precursors, and gene organizations were established. A breakthrough consisted in the discovery of numerous AMP variants, even within the same animal. In addition, computer homology revealed the existence of already known AMPs in new studied molluscan species