The echinoderm innate humoral immune response

Abstract: Multicellular organisms have an immune system, which is essential for the survival of living beings. Interest in the immune system has been expanded since common characteristics of innate immunity between Drosophila melanogaster (Meigen, 1830) and mammals were discovered in the 1980. Since then, immunology has mainly focused on the adaptive immune system that seems to be restricted to vertebrates. Unlike the innate immunity, the adaptive one is acquired after exposure to a specific antigen (Ag) and includes: antigen-presenting cells such as macrophages, proliferation of B and T lymphocytes, Ag-specific antibody/cytokine production and immunological memory. Innate immunity is instead a process of cellular defense at low specificity, which is designed to prevent and combat infectious agents that penetrate at the tissue level, and may be the only form of immunity present in invertebrates such as sea urchins. The immune system of invertebrates acts through (i) cellular components (cell-mediated immunity) in which the effectors of defense reactions are represented by immune cells; (ii) soluble factors (humoral immunity), secreted by the immune cells, such as lectins, agglutinins, lysins, antimicrobial peptides and the prophenoloxidase (proPO) activating system, which act in parallel with the immune cells to fight pathogens and other foreign substances. Here we aim to deepen the study on humoral immunity of invertebrates, especially referring to the phylum Echinodermata because of its features shared with protostomes and other deuterostomes, and suggesting a key step during evolution

Dielectric Characterization of Breast Biopsied Tissues as Pre-Pathological Aid in Early Cancer Detection: A Blinded Feasibility Study

Dielectric characterization has significant potential in several medical applications, providing valuable insights into the electromagnetic properties of biological tissues for disease diagnosis, treatment planning, and monitoring of therapeutic interventions. This work presents the use of a custom-designed electromagnetic characterization system, based on an open-ended coaxial probe, for discriminating between benign and malignant breast tissues in a clinical setting. The probe’s development involved a well-balanced compromise between physical feasibility and its combined use with a reconstruction algorithm known as the virtual transmission line model (VTLM). Immediately following the biopsy procedure, the dielectric properties of the breast tissues were reconstructed, enabling tissue discrimination based on a rule-of-thumb using the obtained dielectric parameters. A comparative analysis was then performed by analyzing the outcomes of the dielectric investigation with respect to conventional histological results. The experimental procedure took place at Complejo Hospitalario Universitario de Toledo—Hospital Virgen de la Salud, Spain, where excised breast tissues were collected and subsequently analyzed using the dielectric characterization system. A comprehensive statistical evaluation of the probe’s performance was carried out, obtaining a sensitivity, specificity, and accuracy of 81.6%, 61.5%, and 73.4%, respectively, compared to conventional histological assessment, considered as the gold standard in this investigation

Structure and enzyme content of sea urchin cytolytic granules

Amoebocytes of the echinoderm (sea urchin), Paracentrotus lividus are responsible for cytotoxic activity. The cytotoxic event requires contact between effector and target cells and calcium-dependent hemolysins, causing disintegration and lysis of target cells. The amoebocytes contain cytoplasmic, lytic granules which are electron-dense and lucid. Isolated granules consist of morphologically empty vesicles. Acid, but not alkaline, proteases were the degradative enzyme constituents of isolated amoebocyte granules. The similarity of mammalian NK cells and putative equivalents in sea urchins is discussed and compared with respect to the evolution of cytotoxicity

ADHESIVE PROPERTIES OF SEA CUCUMBER COELOMOCYTES.

The adhesive properties of the coelomocytes of the sea cucumber, Holothuria polii, have been investigated by studying their ability to attach to glass coverslips in vitro, and their morphology examined by scanning electron microscopy. Both amoebocytes and spherule cells in cell suspensions attached themselves to glass coverslips, but spreading activity was restricted to an amoebocyte subset which assumed an extremely flattened morphology