Tumors in invertebrates

Tumors are ectopic masses of tissue formed by due to an abnormal cell proliferation. In this review tumors of several invertebrate species are examined. The description of tumors in invertebrates may be a difficult task, because the pathologists are usually inexperienced with invertebrate tissues, and the experts in invertebrate biology are not familiar with the description of tumors. As a consequence, the terminology used in defining the tumor type is related to that used in mammalian pathology, which can create misunderstandings in some occasions

The self/non-self dualism is still so marked as it was considered for a long time?

For several decades the immune system has been described mainly as a molecular machinery aimed to recognize and eliminate all the non-self molecules or organisms. Actually, recent evidences support the presence of a constant cross talk between the immune system and microorganisms that live within the host as symbionts resulting in the tolerance of non-self bacteria and yeasts. As a whole, the “defensive” role of immunity, described as highly prominent in several contexts of the modern biosciences, should be revised taking into account that the immune system defined during evolution which organisms have to be excluded and killed, and which have to be maintained. These new evidences support the idea that each animal is a dynamic and context-dependent entity with a mixed and tolerant self

ACTH in invertebrates: A molecule for all seasons

In vertebrate and invertebrate models, adrenocorticotropic hormone (ACTH) belongs to the melanocortin group of related peptides, which share a common precursor, pro-opiomelanocortin (POMC). Functional experiments indicate that in invertebrates, ACTH plays a major role in several biological functions. ACTH, whose effects have been conserved during evolution more than its amino acidic sequence, is, directly or indirectly, able to contrast agents that perturb a body’s homeostasis. Here we review evidence highlighting the involvement of ACTH and ACTH-like molecules in the response of invertebrate models versus immune, environmental and parasitic challenges

The main actors involved in extending the invertebrate life span

Classical invertebrate models, i.e., Drosophila melanogaster and Caenorhabditis elegans, have provided the keys to understand the life span regulation. In the present paper we summarize the mechanisms involved in this process with particular emphasis on the role of the fly fat body. It is interesting to note that pathways which lead to an extension of life span are highly conserved in animals so that “longevity pathways” identified in invertebrates provide templates for the identification of genes and drugs that regulate longevity and diseases also in other animals, including mammals

Circulating hemocytes from larvae of the paper wasp Polistes dominulus (Hymenoptera, Vespidae)

Circulating hemocytes from larval stages of the paper wasp Polistes dominulus were characterized by light and transmission electronmicroscopy. Three types were identified: prohemocytes, plasmatocytes and granulocytes. The first two are agranular cells while the latterpresent typical cytoplasmic inclusions called granules. Plasmatocytes differ from prohemocytes being larger, showing lower nucleus/cytoplasmratio and they possess many phagolysosomes. The substantial uniformity of most subcellular features and the presence of \u201cintermediate forms\u201d support the \u201csingle-cell theory\u201d i.e., there is only one cell line that originates from the prohemocyte and leads to the granular cell passing through the plasmatocyte. This hypothesis seems to be confirmed by functional tests. Indeed, most part of cells adheres to the glass and is able to phagocytize fluorescent microspheres

Morphochemical age-related changes in the nematode Caenorhabditis elegans: immunoperoxidase localization of cytokine- and growth factor-like molecules

Morphochemical age-related features in the hermaphrodite Caenorhabditis elegans are reported. The study of worms of different ages shows a gradual decline in response to the various histochemical reactions and a disorganization of the components of the gonad during ageing. Using an immunocytochemical procedure, we show for the first time the presence of immunoreactive IL-1alpha and PDGF-AB molecules in neurons from young adult C. elegans. Moreover, TNF-alpha- and PDGF-AB-like molecules are also present in the secretory cells of the pharyngeal terminal bulb. The number of positive cells to anti-cytokine and anti-growth factor antibodies decreases in older worms, suggesting that these molecules may play an important role in worm ageing. The present investigation therefore supports the findings in the literature obtained with different approaches on the crucial role of the nervous and reproductive systems in the life span of C. elegans

Monitoring of the immune efficiency of Mytilus galloprovincialis in Adriatic sea mussel farms in 2005

The monthly evaluation of the cytotoxicity of hemolymph from the mussel Mytilus galloprovincialis revealed some variations in the percentage of cytotoxic animals during the year. Cytotoxicity is confirmed to be a dynamic parameter that can be used as an indicator of immune efficiency and, therefore, of the state of health of the animals

Immune-Neuroendocrine Interactions: Evolution, Ecology, and Susceptibility to Illness

The integration between immune and neuroendocrine systems is crucial for maintaining homeostasis from invertebrates to humans. In the first, the phagocytic cell, i.e., the immunocyte, is the main actor, while in the latter, the principle player is the lymphocyte. Immunocytes are characterized by the presence of pro-opiomelanocortin (POMC) peptides, CRH, and other molecules that display a significant similarity to their mammalian counterparts regarding their functions, as both are mainly involved in fundamental functions such as immune (chemotaxis, phagocytosis, cytotoxicity, etc.) and neuroendocrine (stress) responses. Furthermore, the immune-neuroendocrine system provides vital answers to ecological and immunological demands in terms of economy and efficiency. Finally, susceptibility to disease emerges as the result of a continuous dynamic interaction between the world within and the world outside. New fields such as ecological immunology study the susceptibility to pathogens in an evolutionary perspective while the field of neuro-endocrine-immunology studies the susceptibility from a more immediate perspective

Targets and Effects of Yessotoxin, Okadaic Acid and Palytoxin: A Differential Review

In this review, we focus on processes, organs and systems targeted by the marine toxins yessotoxin (YTX), okadaic acid (OA) and palytoxin (PTX). The effects of YTX and their basis are analyzed from data collected in the mollusc Mytilus galloprovincialis, the annelid Enchytraeus crypticus, Swiss CD1 mice and invertebrate and vertebrate cell cultures. OA and PTX, two toxins with a better established mode of action, are analyzed with regard to their effects on development. The amphibian Xenopus laevis is used as a model, and the Frog Embryo Teratogenesis Assay-Xenopus (FETAX) as the experimental protocol

Circulating phagocytes: The ancient and conserved interface between immune and neuroendocrine function

Immune and neuroendocrine functions display significant overlap in highly divergent and evolutionarily distant models such as molluscs, crustaceans, insects and mammals. Fundamental players in this crosstalk are professional phagocytes: macrophages in vertebrates and immunocytes in invertebrates. Although they have different developmental origins, macrophages and immunocytes possess comparable functions and differentiate under the control of evolutionarily conserved transcription factors. Macrophages and immunocytes share their pools of receptors, signalling molecules and pathways with neural cells and the neuro-endocrine system. In crustaceans, adult transdifferentiation of circulating haemocytes into neural cells has been documented recently. In light of developmental, molecular and functional evidence, we propose that the immune-neuroendocrine role of circulating phagocytes pre-dates the split of protostomian and deuterostomian superphyla and has been conserved during the evolution of the main groups of metazoans