NET amyloidogenic backbone in human activated neutrophils

Activated human neutrophils produce a fibrillar DNA network [neutrophil extracellular traps (NETs)] for entrapping and killing bacteria, fungi, protozoa and viruses. Our results suggest that the neutrophil extracellular traps show a resistant amyloidogenic backbone utilized for addressing reputed proteins and DNA against the non-self. The formation of amyloid fibrils in neutrophils is regulated by the imbalance of reactive oxygen species (ROS) in the cytoplasm. The intensity and source of the ROS signal is determinant for promoting stress-associated responses such as amyloidogenesis and closely related events: autophagy, exosome release, activation of the adrenocorticotrophin hormone/α-melanocyte-stimulating hormone (ACTH/α-MSH) loop and synthesis of specific cytokines. These interconnected responses in human activated neutrophils, that have been evaluated from a morphofunctional and quantitative viewpoint, represent primitive, but potent, innate defence mechanisms. In invertebrates, circulating phagocytic immune cells, when activated, show responses similar to those described previously for activated human neutrophils. Invertebrate cells within endoplasmic reticulum cisternae produce a fibrillar material which is then assembled into an amyloidogenic scaffold utilized to convey melanin close to the invader. These findings, in consideration to the critical role played by NET in the development of several pathologies, could explain the structural resistance of these scaffolds and could provide the basis for developing new diagnostic and therapeutic approaches in immunomediated diseases in which the innate branch of the immune system has a pivotal role.

Predictors of Ominous Outcome in Infants Undergone to Cardiac Surgery and Cardiopulmonary by-Pass: S100B Protein

S100B protein has been recently proposed as a consolidated marker of brain damage and death in adult, children and newborn patients. The present study evaluates whether the longitudinal measurement of S100B at different perioperative time-points may be a useful tool to identify the occurrence of perioperative early death in congenital heart disease (CHD) newborns. We conducted a case-control study in 88 CHD infants, without pre-existing neurological disorders or other co-morbidities, of whom 22 were complicated by perioperative death in the first week from surgery. Control group was composed by 66 uncomplicated CHD infants matched for age at surgical procedure. Blood samples were drawn at five predetermined time-points before during and after surgery. In all CHD children, S100B values showed a pattern characterized by a significant increase in protein's concentration from hospital admission up to 24-h after procedure reaching their maximum peak (P<0.01) during cardiopulmonary by-pass and at the end of the surgical procedure. Moreover, S100B concentrations in CHD death group were significantly higher (P<0.01) than controls at all monitoring time-points. The ROC curve analysis showed that S100B measured before surgical procedure was the best predictor of perioperative death, among a series of clinical and laboratory parameters, reaching at a cut-off of 0.1 μg/L a sensitivity of 100% and a specificity of 63.7%. The present data suggest that in CHD infants biochemical monitoring in the perioperative period is becoming possible and S100B can be include among a series of parameters for adverse outcome prediction.

Uptake, cell penetration and metabolic processing of exogenously administered GM1 ganglioside in rat brain

GM1 ganglioside, after intravenous injection into rats, is absorbed and taken up by various organs and tissues, including brain. The capacity of brain to take up gangliosides, referred to weight unit, is comparable to that of kidney and muscle. After injection of [Gal-(3)H]GM1 a relevant portion of brain associated radioactivity resided in the soluble fraction and was of a volatile nature. After brain subcellular fractionation, the lysosomal, plasma membrane and Golgi apparatus fractions carried the highest specific radioactivity. In addition, an enriched fraction of brain capillaries was highly labelled, suggesting that GM1 ganglioside is also tightly bound to the vessel walls. The metabolic events encountered in brain by exogenous gangliosides were investigated, in detail, after intracisternal injection of [Sph-(3)H]GM1. The results obtained demonstrate that GM1 is extensively metabolized in brain. Besides the degradation products (GM2, GM3, lactosylceramide, glucosylceramide, ceramide), compounds of a biosynthetic origin were also found to be formed: these include GD1a, GD1b and sphingomyelin. All the above results could indicate that gangliosides, after intravenous administration to rats, are taken up by brain, bind to the capillary network, penetrate into neural cells, associate to both plasma membranes and intracellular structures and undergo metabolic processing with formation of a number of products of both catabolic and biosynthetic origin.

5 PARTHENOGENETIC EMBRYONIC STEM CELLS ARE CONNECTED BY FUNCTIONAL INTERCELLULAR BRIDGES

We previously reported that parthenogenetic stem cells display abnormal centrosome and spindle formation that results in severe chromosome missegregation, with a high incidence of hypoploid karyotypes. Unexpectedly, this is not accompanied by a correspondingly high rate of apoptosis and, by contrast, parthenogenetic cells share the pluripotency, self-renewal and in vitro differentiation properties of their bi-parental counterparts. We hypothesise that this is possible through a series of adaptive mechanisms that include the presence of intercellular bridges similar to those that connect germ cells during spermatogenesis. This would provide a way for mutual exchange of missing cell products, thus alleviating the unbalanced chromosome distribution that would otherwise hamper normal cell functions. The presence of intercellular bridges was investigated in pig parthenogenetic embryonic stem cells (PESC) by transmission electron microscopy (TEM). Cultured cells were fixed in 2% glutaraldehyde and post-fixed in 1% osmic acid. After standard dehydration in ethanol series, samples were embedded in an Epon-Araldite 812 mixture and sectioned with a Reichert Ultracut S ultratome (Leica). Thin sections were stained and observed with a Jeol 1010 electron microscope. Pig PESC were also subjected to scanning electron microscopy (SEM). To this purpose, they were fixed and dehydrated as described above, covered with a 9-nm gold film by flash evaporation of carbon in an Emitech K 250 sputter coater (Emitech) and examined with an SEM-FEG Philips XL-30 microscope. To demonstrate functional trafficking activity through intercellular canals, fluorescent 10-kDa dextran was injected into the cytoplasm of a single cell with FemtoJet Microinjector (Eppendorf). Movement of the molecule from the injected cell to others was observed with a Nikon Eclipse TE200 microscope. Ultra-structural analysis of PESC demonstrated the existence of intercellular bridges that ensured cytoplasmic continuity among cells. These canals appeared variable in size and were characterised by the presence of stabilising actin patches. Furthermore, extensive movement of 10-kDa dextran among cells demonstrated functional intercellular trafficking through these communication canals, suggesting their use for transfer of mRNA, proteins and ribosomes among cells. Our results demonstrate that PESC present a wide network of functional intercellular bridges that may constitute an adaptive mechanism to support normal cell functions. This process is commonly observed in transformed cells and gives further support to the recent hypothesis that suggests the existence of common features and links between oncogenesis and self-renewal in pluripotent cell lines. Supported by AIRC IG 10376. PG was supported by INGM.

Reversine increases multipotent human mesenchymal cells differentiation potential

Among different human stem cell sources, adult mesenchymal stem cells from bone marrow (BMSCs), and more recently from adipose tissues (ASCs), have shown their capability to differentiate into a variety of different cell types, including osteoblasts, adipocytes, and muscle cells. However, mesenchymal stem cell differentiation toward certain cell types (including skeletal and cardiac muscle), while shown to be achievable, still suffers of low yields and needs to be greatly improved before any therapeutic application could be foreseen. A possible way of achieving this goal is by using a chemical-pharmacological approach to increase stem cell plasticity. Along this line, we envisioned the possibility of pre-treating BMSCs and ASCs with reversine, a synthetic purine that has been shown to induce adult cells de-differentiation. In the current study we tested reversine effects on both BMSCs and ASCs to increase their differentiation toward osteoblasts, smooth and skeletal muscle cells. Reversine pre-treatment, at very low concentration (50 nM), caused a marked increase in the differentiation yields of both BMSCs and ASCs.

Effects of coffee and tea consumption on urinary incontinence in female twins

OBJECTIVES

To assess the effect of coffee and tea consumption on symptoms of urinary incontinence.

DESIGN

Population-based study.

SETTING

The Swedish Twin Register.

POPULATION

In 2005, all twins born between 1959 and 1985 in Sweden (n = 42,852) were invited to participate in a web-based survey to screen for common complex diseases and common exposures. The present study was limited to female twins with information about at least one urinary symptoms and coffee and tea consumption (n = 14,031).

MAIN OUTCOME MEASURE

The association between coffee and tea consumption and urinary incontinence, as well as nocturia, was estimated as odds ratios (ORs) with 95% confidence intervals.

RESULTS

Women with a high coffee intake were at lower risk of any urinary incontinence (OR 0.78, 95% CI 0.64-0.98) compared with women not drinking coffee. Coffee intake and incontinence subtypes showed no significant associations whereas high tea consumption was specifically associated with a risk for overactive bladder (OR 1.34, 95% CI 11.07-1.67) and nocturia (OR 1.18, 95% CI 1.01-1.38). Results from co-twin control analysis suggested that the associations observed in logistic regression were mainly the result of familial effects.

CONCLUSIONS

This study suggests that coffee and tea consumption has a limited effect on urinary incontinence symptoms. Familial and genetic effects may have confounded the associations observed in previous studies.

No survival benefit from early-start dialysis in a population-based, inception cohort study of Swedish patients with chronic kidney disease

OBJECTIVE

To investigate how the timing of dialysis initiation is associated with mortality.

DESIGN

Population-based, prospective, observational cohort study.

SETTING

Clinical laboratories (n = 69) provided information on all patients in Sweden whose serum creatinine level for the first time and exceeded 3.4 mg dL(-1) (men) or 2.8 mg dL(-1) (women) between 20 May 1996 and 31 May 1998.

SUBJECTS

All patients (n = 901), aged 18-74 years, in whom the cause of serum creatinine elevation was chronic kidney disease, were included in the study; participants were interviewed and followed for 5-7 years.

MAIN OUTCOME MEASURES

Information on date of death was obtained from a national Swedish population register. Early-start dialysis [estimated glomerular filtration rate from serum creatinine (eGFR) ≥7.5 mL min(-1) per 1.73 m(2)] was compared to late start of dialysis (eGFR <7.5 mL min(-1) per 1.73 m(2)), and no dialysis. Relative risk [hazard ratio (HR)] of death was modelled with time-dependent multivariate Cox proportional hazards regression.

RESULTS

Mean eGFR was 16.1 mL min(-1) per 1.73 m(2) at inclusion and 7.6 mL min(-1) per 1.73 m(2) at the start of dialysis. Among the 385 patients who started dialysis late, 36% died during follow-up compared to 52% of 323 who started early. The adjusted HR for death was 0.84 [95% confidence interval (CI) 0.64, 1.10] among late versus early starters. The mortality among nondialysed patients increased significantly at eGFR below 7.5 mL min(-1) per 1.73 m(2) (HR 4.65; 95% CI 2.28, 9.49; compared to eGFR 7.5-10 mL min(-1) per 1.73 m(2)). After the start of dialysis, the mortality rate further increased. Compared to nondialysed patients with eGFR ≤15 mL min(-1) per 1.73 m(2), adjusted HR was 2.65 (95% CI 1.80, 3.89) for patients receiving dialysis.

CONCLUSION

We found no survival benefit from early initiation of dialysis.

Cell reprogramming: expectations and challenges for chemistry in stem cell biology and regenerative medicine

The possibility of reprogramming adult somatic cells into pluripotent stem cells (iPSCs) has generated a renewed interest into stem cell research and promises to overcome several key issues, including the ethical concerns of using human embryonic stem cells and the difficulty of obtaining large numbers of adult stem cells (Belmonte et al., Nat Rev Genet, 2009). This approach is also not free from challenges like the mechanism of the reprogramming process, which has yet to be elucidated, and the warranties for safety of generated pluripotent cells, especially in view of their possible therapeutic use. Very recently, several new reprogramming methods have surfaced, which seem to be more appropriate than genetic reprogramming. Particularly, chemically induced pluripotent cells (CiPSs), obtained with recombinant proteins or small synthetic molecules, may represent a valid approach, simpler and possibly safer than the other ones.

324 CELL LINES DERIVED FROM MAMMALIAN PARTHENOGENETIC EMBRYOS DISPLAY ABNORMAL CHROMOSOME COMPLEMENTS AND ABERRANT CENTRIOLE NUMBER

Mature oocytes can be activated in vitro, leading to the generation of parthenotes that will develop in culture forming blastocysts morphologically indistinguishable from those derived from fertilized eggs. Parthenotes have been used as a source of pluripotent cells that show the traditional features associated with their biparental counterpart: expression of totipotency markers, telomerase activity, embryoid body formation, in vitro differentiation and, in most cases, teratoma formation. However, many aspects still need to be elucidated and, in particular, little attention has been paid to the inci- dence of aneuploidy in these cells. Limited data available for parthenotes derived from different mammalian species indicate a high rate of aneuploidy, whichis consideredtobecaused by the lackofthe paternal contribution, because alterations of the centrosome are knowntolead to multipolar spindles that, in turn, cause aneuploid cells. In this study, we analyzed the rate of aneuploidy and centriole distribution (as a marker of centrosome anomalies) in pluripotent cell lines (pSC) previously derived in our laboratory from pig parthenogenetic embryos and in primary fibroblast cultures and sections obtained from sheep parthenogenetic fetuses (n = 3) that reached 24 days of development in vivo. This protocol was chosen to separate the effect related tooocyte activation from those of the procedures used to derive pSC lines. Centriole number and distribution were assessed both by immunocy- tochemical analysis using an anti-centrin-1 antibody (1 : 200, Abcam, Cambridge, UK) and an appropriate secondary antibody, and by ultrastructural evaluation of thin sections, using a Jeol 1010 EX electron microscope (Jeol, Tokyo, Japan). Karyotyping was performed on mitotically active cells. Metaphases were fully karyotyped under a Leica HC microscope (Wetzlar, Germany). Images were then captured with a Leica DC250 digital camera and cells karyotyped using the Leica CW4000 Karyo software. The results obtained indicate that cell lines of parthenogenetic origin have, in all examined cases, an incidence of aneuploidy significantly higher than that of their respective controls. In particular, although the diploid configuration represented the modal value, the majority of the cells displayed a consistently lower number of chromosomes, between <1N (hypohaploid) and >1N to <2N (hypodiploid).This resultis possibly related toa lossofchromosomes during the mitotic process.Ahigher incidence ofmultiple centrioles was also detected, suggesting that aneuploidy may be related to the lack of paternal contribution that results in abnormal centrosome formation, incorrect control of the process of spindle rearrangement, and consequent chromosomal malsegregation.Abnormal segregation and multicentriolar distribution were not limited to parthenogenetic cell lines but was observed in parthenotes as well, indicating that culture artifacts are unlikely to be the cause. PUR 2007, PUR 2008.

Growth Factors and Chemokines: A Comparative Functional Approach Between Invertebrates and Vertebrates

Growth factors and cytokines control and coordinate a broad spectrum of fundamental cellular functions, and are evolutionarily conserved both in vertebrates and invertebrates. In this review, we focus our attention on the functional phylogenetic aspects of growth factors/cytokines like the Transforming Growth Factor-beta (TGF-beta), the Connective Tissue Growth Factor (CTGF), and the Vascular Endothelial Growth Factor (VEGF). We will also delve into the activites of two chemokine families, interleukin (IL)-8 (or CXCL8) and CC chemokine ligand 2/monocyte chemoattractant protein-1 (CCL2). These molecules have been selected for their involvement in immune responses and wound healing processes, where they mediate and finely regulate various regeneration processes like angiogenesis or fibroplasia, not only in vertebrates, but also in invertebrates.

Hematopoietic cell formation in leech wound healing

The angiogenic process in vertebrates and hirudineans has been compared. The leech Hirudo medicinalis, subjected to an angiogenic stimulus (surgical explant or cytokine treatment) responds, as a vertebrate, with the formation of an extensive network of new vessels accompanied by the production of circulating cells. The reviewed data confirm the surprising similarity between hirudinean and vertebrate processes in wound healing, and suggest that basic common events such as antigenic expressions of endothelial and hemopoietic cells, cytokine secretion and regulation as well as extracellular matrix interactions, are conserved and extended across diverse species, tissues and developmental phases.

Structure and function of the extraembryonic membrane persisting around the larvae of the parasitoid Toxoneuron nigriceps

The embryo of Toxoneuron nigriceps (Hymenoptera, Braconidae) is surrounded by an extraembryonic membrane, which, at hatching, releases teratocytes and gives rise to a cell layer embedding the body of the 1st instar larva. This cell layer was studied at different developmental times, from soon after hatching up to the first larval moult, in order to elucidate its ultrastructural, immunocytochemical and physiological function. The persisting "larval serosa" shows a striking structural and functional complexity: it is a multifunctional barrier with protective properties, limits the passage of macromolecules and it is actively involved in the enzymatic processing and uptake of nutrients. The reported results emphasizes the important role that the embryo-derived host regulation factors may have in parasitism success in Hymenoptera koinobionts.

Ganglioside/glycosphingolipid turnover: new concepts

In this review focus is given to the metabolic turnover of gangliosides/glycosphingolipids. The metabolism and accompanying intracellular trafficking of gangliosides/glycosphingolipids is illustrated with particular attention to the following events: (a) the de novo biosynthesis in the endoplasmic reticulum and Golgi apparatus, followed by vesicular sorting to the plasma membrane; (b) the enzyme-assisted chemical modifications occurring at the plasma membrane level; (c) the internalization via endocytosis and recycling to the plasma membrane; (d) the direct glycosylations taking place after sorting from endosomes to the Golgi apparatus; (e) the degradation at the late endosomal/lysosomal level with formation of fragments of sugar (glucose, galactose, hexosamine, sialic acid) and lipid (ceramide, sphingosine, fatty acid) nature; (f) the metabolic recycling of these fragments for biosynthetic purposes (salvage pathways); and (g) further degradation of fragments to waste products. Noteworthy, the correct course of ganglioside/glycosphingolipid metabolism requires the presence of the vimentin intracellular filament net work, likely to assist intracellular transport of sphingoid molecules. ut of the above events those that can be quantitatively evaluated with acceptable reliability are the processes of de novo biosynthesis, metabolic salvage and direct glycosylation. Depending on the cultured cells employed, the percentage of distribution of de novo biosynthesis, salvage pathways, and direct glycosylation, over total metabolism were reported to be: 35% (range: 10-90%) for de novo biosynthesis, 7% (range: 5-10%) for direct glycosylation, and 58% (range: 10-90%) for salvage pathways. The attempts made to calculate the half-life of overall ganglioside turnover provided data of unsure reliability, especially because in many studies salvage pathways were not taken into consideration. The values of half-life range from 2 to 6.5 h to 3 days depending on the cells used. Available evidence for changes of ganglioside/glycosphingolipid turnover, due to extracellular stimuli, is also considered and discussed.

Molecular cloning and characterization of NEU4, the fourth member of the human sialidase gene family

Several mammalian sialidases have been cloned so far and here we describe the identification and expression of a new member of the human sialidase gene family. The NEU4 gene, identified by searching sequence databases for entries showing homologies to the human cytosolic sialidase NEU2, maps in 2q37 and encodes a 484-residue protein. The polypeptide contains all the typical sialidase amino acid motifs and, apart from an amino acid stretch that appears unique among mammalian sialidases, shows a high degree of homology for NEU2 and the plasma membrane-associated (NEU3) sialidases. RNA dot-blot analysis showed a low but wide expression pattern, with the highest level in liver. Transient transfection in COS7 cells allowed the detection of a sialidase activity toward the artificial substrate 4MU-NeuAc in the acidic range of pH. Immunofluorescence staining and Western blot analysis demonstrated the association of NEU4 with the inner cell membranes.

Vascular endothelial growth factor is involved in neoangiogenesis in Hirudo medicinalis (Annelida, Hirudinea)

Vascular endothelial growth factor (VEGF) is fundamental in vertebrates for correct development of blood vessels. However, there are only few data about the presence of VEGF in invertebrates. In this study the role of VEGF in neovessel formation is investigated in Hirudo medicinalis. The leech is able to respond to administration of human VEGF by formation of new vessels. The response of H. medicinalis to this growth factor is explained by the presence of two specific VEGF-like receptors (Flt-1/VEGFR-1 and Flk-1/VEGFR-2) as demonstrated by immunohistochemistry and biochemical analysis. The VEGF-like produced by this annelid following surgical stimulation determines not only blood vessel formation, proliferation of vascular endothelial cells but also an increase of cytoplasmic calcium levels. The administration of specific VEGF receptor antibodies can inhibit angiogenesis in leeches previously stimulated with VEGF.

Salvage pathways in glycosphingolipid metabolism

In this review, the focus is on the role of salvage pathways in glycosphingolipid, particularly, ganglioside metabolism. Ganglioside de novo biosynthesis, that begins with the formation of ceramide and continues with the sequential glycosylation steps producing the oligosaccharide moieties, is briefly outlined in its enzymological and cell-topological aspects. Neo-synthesized gangliosides are delivered to the plasma membrane, where their oligosaccharide chains protrude toward the cell exterior. The metabolic fate of gangliosides after internalization via endocytosis is then described, illustrating: (a) the direct recycling of gangliosides to the plasma membrane through vesicles gemmated from sorting endosomes; (b) the sorting through endosomal vesicles to the Golgi apparatus where additional glycosylations may take place; and (c) the channelling to the endosomal/lysosomal system, where complete degradation occurs with formation of the individual sugar (glucose, galactose, hexosamine, sialic acid) and lipid (ceramide, sphingosine, fatty acid) components of gangliosides. The in vivo and in vitro evidence concerning the metabolic recycling of these components is examined in detail. The notion arises that these salvage pathways, leading to the formation of gangliosides and other glycosphingolipids, sphingomyelin, glycoproteins and glycosaminoglycans, represent an important saving of energy in the cell economy and constitute a relevant event in overall ganglioside (or glycosphingolipid, in general) turnover, covering from 50% to 90% of it, depending on the cell line and stage of cell life. Sialic acid is the moiety most actively recycled for metabolic purposes, followed by sphingosine, hexosamine, galactose and fatty acid. Finally, the importance of salvage processes in controlling the active concentrations of ceramide and sphingosine, known to carry peculiar bioregulatory/signalling properties, is discussed.

Hirudo medicinalis: a new model for testing activators and inhibitors of angiogenesis

An increasing body of evidence indicates that in the leech Hirudo medicinalis the angiogenic process is finely regulated and coordinated by the botryoidal tissue. In this paper we provide evidence on the involvement of botryoidal tissue cells in angiogenesis induced in H. medicinalis by a variety of stimuli including surgical wounds or the administration of modulators of neovascularization. Interestingly, we show that either human activators of vascular cell growth, or anti-angiogenic peptides like angiostatin and endostatin, or the drug mitomycin, can induce a prompt biological response in H. medicinalis. We show as well that angiogenesis in this invertebrate shares a surprising degree of similarity with neovascularization in vertebrates, both at the biochemical and cellular levels, because it involves similar growth factors/growth factor receptors, and relies on analogous cell-cell or cell-matrix interactions. For these reasons we suggest that H. medicinalis can be used as a reproducible model for testing activators or inhibitors of angiogenesis, and for investigating the biochemical, ultrastructural and cellular processes involved in new vessel formation.

GM3 ganglioside inhibits endothelin-1-mediated signal transduction in C6 glioma cells

We found that sparse and confluent C6 glioma cells differ both in GM3 content, which increases with cell density, and in endothelin-1 (ET-1)-induced phosphoinositide hydrolysis, which was markedly higher in the sparse cells than in the confluent. Also after manipulation of the cellular GM3 content through treatment with exogenous GM3 or with drugs known to affect GM3 metabolism, the ET-1 effect was inversely related to GM3 cellular levels. Cell treatment with an anti-GM3 mAb resulted in the enhancement of ET-1-induced phospholipase C activation and restored the capacity of GM3-treated cells to respond to ET-1. These findings suggest that the GM3 ganglioside represents a physiological modulator of ET-1 signaling in glial cells.

Nitric oxide production in living neurons is modulated by sphingosine: a fluorescence microscopy study

An investigation was carried out into the possible effect of sphingosine (Sph) on nitric oxide (NO) production in living neurons. Differentiated granule cells were used in a dynamic videoimaging analysis of single cells labeled, simultaneously, with FURA-2 and the NO indicator 4,5-diaminofluorescein. The results demonstrate that Sph exerts a potent inhibitory effect on the Ca2+-dependent production of NO, without modifying the [Ca2+]i. The effect appears to be specific as neither ceramide nor Sph-1-phosphate had any effect on the NO and [Ca2+]i levels. The data demonstrate that Ca2+-dependent NO production is a specific Sph target in living granule cells, suggesting that this bioactive sphingoid plays a relevant role in neuronal NO signaling.

Larval anatomy and structure of absorbing epithelia in the aphid parasitoid Aphidius ervi Haliday (Hymenoptera, Braconidae)

The present work describes Aphidius ervi Haliday (Hymenoptera, Braconidae) larval anatomy and development, focusing on time-related changes of body structure and cell ultrastructure, especially of the epithelial layers involved in nutrient absorption. Newly hatched 1st instar larvae of A. ervi are characterised by gut absence and a compact cluster of cells makes up their body. As the parasitoid larva develops, the central undifferentiated cell mass becomes hollowed out, leading to the formation of gut anlage. This suggests that absorption of nutrients at that stage may take place through the body surface, as more directly demonstrated by the occurrence on the epidermis of proteins associated with transepithelial transport, such as Na(+)/K(+)-ATPase and alkaline phosphatase (ALP). Second instar larvae show the presence of the gut with a well-differentiated brush border and a peritrophic membrane. Gut cells are filled by masses of glycogen granules and lipid droplets. The tracheal system starts to be visible. The haemocoel becomes evident in late 2nd instar, and contains large silk glands. Mature 3rd instar larvae are typically hymenopteriform. The midgut accounts for most of the body volume and is actively involved in nutrient absorption, as indicated by the well developed brush border and by the presence of Na(+)/K(+)-ATPase and ALP on the basolateral and luminal membrane respectively. At this stage, large lipid droplets have gradually replaced the cellular glycogen stores in the midgut cells. The tracheae are completely differentiated, but their internal lumen still contains fibrillar material, suggesting that they are not functional as long as host fluids bath the parasitoid larva. In late 3rd instar larvae, silk glands, structurally similar to Malpighian tubules, show a very intense vesicular traffic toward the internal lumen, which, eventually, results in being filled by secretion products, suggesting the possible recycling of metabolic waste products during mummy formation.

Immunoseparation of sphingolipid-enriched membrane domains enriched in Src family protein tyrosine kinases and in the neuronal adhesion molecule TAG-1 by anti-GD3 ganglioside monoclonal antibody

Rat cerebellar granule cells differentiated in culture were fed [1-(3)H]sphingosine, allowing the metabolic radiolabelling of all cell sphingolipids and phosphatidylethanolamine. A detergent-insoluble sphingolipid-enriched membrane fraction, containing about 60% of cell sphingolipids, but only trace amounts of phosphatidylethanolamine, was prepared from [1-(3)H]sphingosine-fed cells by sucrose gradient centrifugation. This fraction was enriched in the Src family protein tyrosine kinases c-Src, Lyn and Fyn and in the GPI-anchored neuronal adhesion molecule TAG-1. The cell lysate and the sphingolipid-enriched membrane fraction were subjected to immunoprecipitation with anti-GD3 ganglioside monoclonal antibody R24, under experimental conditions designed to preserve the integrity of the domain. The radioactive lipid composition of the immunoprecipitates obtained from the cell lysate and from the sphingolipid-enriched fraction were very similar, and closely resembled the sphingolipid composition of the whole sphingolipid-enriched membrane fraction. In fact, the immunoprecipitates contained, together with GD3 ganglioside, all cell glycosphingolipids and sphingomyelin, whereas they did not contain phosphatidylethanolamine. Moreover, cholesterol and phosphatidylcholine were detected in the immunoprecipitates by qualitative TLC analysis followed by colourimetric visualization. c-Src, Lyn, Fyn and TAG-1 were associated with the anti-GD3 antibody immunoprecipitate. These proteins were not detected in the immunoprecipitates obtained under experimental conditions different from those designed to preserve the integrity of the domain. These data suggest that a membrane domain containing cholesterol, phosphatidylcholine, sphingolipids and proteins can be separated from the total cell membranes by anti-GD3 antibody immunoprecipitation, and that the association of c-Src, Fyn, Lyn, and TAG-1 with the sphingolipid-enriched domain is mediated by the interaction with a complex lipid environment, rather than by specific interactions with a single sphingolipid species.

Ultrastructure and functional versatility of hirudinean botryoidal tissue

In leeches, the botryoidal tissue is composed of two different cell types--granular botryoidal cells and flattened endothelial-like cells--localized in the loose connective tissue between the gut and the body wall sac. We have observed that the botryoidal tissue undergoes functional and structural modifications in response to the different needs arising during the life-cycle of the animal. In healthy, untreated leeches, botryoidal cells are organized in cords or clusters, sometimes surrounding few, small lacunae. Conversely, in wounded animals we have observed the transition of the botryoidal tissue from cluster/cord-like structures to a hollow/tubular architecture, typical of pre-vascular structures. We have documented in botryoidal cell cytoplasm the presence of large calcium storage. Moreover, the cytoplasm of botryoidal cells was filled with granules of different form and size, containing iron or melanin, as tested by classic histochemical methods. The presence of elements like iron and calcium was confirmed by the well-established EDS analysis. In response to a surgical wound, botryoidal tissue cells changed their shape and formed new capillary vessels. Concurrently, botryoidal cells secreted iron from cytoplasmic granules into the new cavity: this secretory activity appeared to be related to intracellular calcium fluctuations. At the end of the angiogenic process, botryoidal cells lost their contact with the basal lamina and moved freely in the circulating fluid towards the lesioned area. Interestingly, circulating botryoidal cells were found to carry melanin in the wounded area. This function is probably involved in defense processes. Thus, we have shown that stimulated botryoidal tissue displays a variety of striking structural, secretory and defensive activities.

Changes in the lipid turnover, composition, and organization, as sphingolipid-enriched membrane domains, in rat cerebellar granule cells developing in vitro

In the present paper, we report on the properties of sphingolipid-enriched domains of rat cerebellar granule cells in culture at different stages of neuronal development. The major lipid components of these domains were glycerophospholipids and cholesterol. Glycerophospholipids were 45-75% and cholesterol 15-45% of total lipids of the domains. This corresponded to 5-17% of total cell glycerophospholipids and 15-45% of total cell cholesterol. Phosphatidylcholine, mainly dipalmitoylphosphatidylcholine, was 66-85% of all the glycerophospholipids associated with these domains. Consequently, the palmitoyl residue was significantly enriched in the domains. The surface occupied by these structures increased during development. 40-70% of cell sphingolipids segregated in sphingolipid-enriched membrane domains, with the maximum ganglioside density in fully differentiated neurons. A high content of ceramide was found in the domains of aging neurons. Then, the sphingolipid/glycerophospholipid molar ratio was more than doubled during the initial stage of development, whereas the cholesterol/glycerophospholipid molar ratio gradually decreased during in vitro differentiation. Phosphorylated phosphoinositides, which were scant in the domains of undifferentiated cells, dramatically increased during differentiation and aging in culture. Proteins were minor components of the domains (0.1-2.8% of all domain components). Phosphotyrosine-containing proteins were selectively recovered in the sphingolipid-enriched domain. Among these, Src family protein-tyrosine kinases, known to participate to the process of neuronal differentiation, were associated with the sphingolipid-enriched domains in a way specific for the type of kinase and for the developmental stage of the cell. Proteins belonging to other signaling pathways, such as phosphoinositide 3-kinase and its downstream target, Akt, were not associated with the domains.

Casein phosphopeptides influence calcium uptake by cultured human intestinal HT-29 tumor cells

We investigated the direct effects of casein phosphopeptides (CPP), which are formed by the proteolytic degradation of alpha- and beta-caseins, on calcium uptake by human HT-29 intestinal tumor cells, which undergo an enterocytically oriented differentiation in culture. A commercial preparation containing a mixture of purified CPP and an individual CPP of 25 amino acids, both containing the characteristic Ca(2+) binding motif, ser(P)-ser(P)-ser(P)-glu-glu, were employed. The study was performed at the single-cell level and on a cell population and measured the changes in cytosolic calcium concentration before and after CPP addition. In the presence of 2 mmol/L extracellular calcium, both CPP preparations induced a transient rise of free intracellular calcium ions, which did not influence ATP-induced release of calcium from intracellular stores, and which disappeared completely in the absence of extracellular calcium. Pretreatment of these cells with thapsigargin, which completely empties the intracellular calcium stores, did not abolish the cell responses to CPP. Repetitive stimulation of HT-29 cells with CPP always elicited a transient calcium rise, suggesting a lack of desensitization. The CPP-stimulated cytosolic calcium rise was dependent on CPP dose, in a seemingly nonsaturating mode, and on cell numbers. All of this is consistent with the hypothesis that CPP do not influence membrane-bound receptors or ion channels, but may act as calcium ionophores or calcium carriers across the membrane. The reported findings provide a new basis on which to assess the possibility that CPP enhance calcium absorption and bioavailability in animals.

Different behavior of ghost-linked acidic and neutral sialidases during human erythrocyte ageing

Acidic and neutral sialidases (pH optimum 4.7 and 7.2, respectively) were assayed on human circulating erythrocytes during ageing. The assays were performed on intact erythrocytes and resealed erythrocyte ghost membranes. From young to senescent erythrocytes the acidic sialidase featured a 2.7-fold and 2.5-fold decrease in specific activity when measured on intact cells or resealed ghost membranes, whereas the neutral sialidase a 5-fold and 7-fold increase, respectively. The Ca2+-loading procedure was employed to mimic the vesiculation process occurring during erythrocyte ageing. Under these conditions the released vesicles displayed an elevated content of acidic sialidase, almost completely linked through a glycan phosphoinositide (GPI) anchor but no neutral sialidase activity, that was completely retained by remnant erythrocytes together with almost all the starting content of sialoglycoconjugates. The loss with vesiculation of acidic sialidase with a concomitant relative increase of neutral sialidase was more marked in young than senescent erythrocytes. The data presented suggest that during ageing erythrocytes loose acidic sialidase, and get enriched in the neutral enzyme, the vesiculation process, possibly involving GPI-anchors-rich membrane microdomains, being likely responsible for these changes. The enhanced neutral sialidase activity might account for the sialic acid loss occurring during erythrocyte ageing.

Basic fibroblast growth factor-induced proliferation of primary astrocytes. evidence for the involvement of sphingomyelin biosynthesis

We recently reported that the marked decrease in cellular ceramide in primary astrocytes is an early event associated with the mitogenic activity of basic fibroblast growth factor (bFGF) (Riboni, L., Viani, P., Bassi, R., Stabieini, A., and Tettamanti, G. (2000) GLIA 32, 137-145). Here we show that a rapid activation of sphingomyelin biosynthesis appears to be the major mechanism responsible for the fall in ceramide levels induced by bFGF. When quiescent astrocytes were treated with bFGF, an increased amount of newly synthesized ceramide (from either l-[(3)H]serine or [(3)H]sphingosine) was directed toward the biosynthesis of sphingomyelin. Conversely, bFGF did not appear to affect ceramide levels by other metabolic pathways involved in ceramide turnover such as sphingomyelin degradation and ceramide biosynthesis, degradation, and glucosylation. Enzymatic studies demonstrating a relevant and rapid increase in sphingomyelin synthase activity after bFGF treatment have provided a convincing explanation for the activation of sphingomyelin biosynthesis. The bFGF-induced increase in sphingomyelin synthase appears to depend on a post-translational activation mechanism. Moreover, in the presence of brefeldin A, the activation of sphingomyelin biosynthesis was abolished, suggesting that the enzyme is located in a compartment other than the Golgi apparatus. Also the phosphatidylcholine-specific phospholipase C inhibitor D609 exerted a potent inhibitory effect on sphingomyelin biosynthesis. Finally, we demonstrate that inhibition of sphingomyelin biosynthesis by brefeldin A or D609 led to a significant inhibition of bFGF-stimulated mitogenesis. All this supports that, in primary astrocytes, the early activation of sphingomyelin synthase is involved in the bFGF signaling pathway leading to proliferation.

Biomodulatory role of ceramide in basic fibroblast growth factor-induced proliferation of cerebellar astrocytes in primary culture

To evaluate the role of ceramide in glial growth, primary cultures of quiescent astrocytes from rat cerebellum were stimulated to proliferate by mitogenic doses of basic fibroblast growth factor (bFGF). Parallel to the bFGF mitogenic effect was a marked, and persistent, decrease in cellular ceramide levels. Both in vitro and in culture metabolic studies have led us to exclude both sphingomyelinase and ceramidase involvement in ceramide level variation. Instead, we found evidence of a functional connection between the decrease in ceramide levels and astrocyte proliferation. In fact, cell growth in bFGF-stimulated astrocytes was inhibited by exogenous ceramide and C2-ceramide, maximal inhibition being obtained at a ceramide concentration of 5-10 microM. Under the same conditions, the dihydroderivatives of ceramides were without effect. Following ceramide treatment, the phosphorylation of the MAP kinase isoforms ERK1/2, key components in bFGF-induced cell proliferation, was examined. The administration of antiproliferative doses of ceramide or C2-ceramide, but not of their dihydroderivatives, resulted in a significant inhibition of ERK1/2 activation. In conclusion, our data indicate that the prompt modulation of ceramide levels by bFGF is an early step associated with the signaling pathways responsible for the mitogenic activity of bFGF in astrocytes.

Integumental amino acid uptake in a carnivorous predator mollusc (Sepia officinalis, Cephalopoda)

The epithelial cells of the integument of body, arms and tentacles of Sepia officinalis present on their apical membrane a well-organised brush border and show the morphological and histochemical characteristics of a typical absorptive epithelium. The ability of the integument to absorb amino acids was investigated both in the arms incubated in vitro and in a purified preparation of brush border membrane vesicles (BBMV). Autoradiographic pictures of the integument after incubation of the arms in sea-water with or without sodium, showed that proline intake was Na+-dependent, whereas leucine intake appeared to be a largely cation-independent process. Time course experiments of labelled leucine, proline and lysine uptakes in BBMV evidenced that these amino acids are accumulated within the vesicles in the presence of an inwardly directed sodium gradient. The sodium-driven accumulation proves that cationic and neutral amino acids are taken up by the apical membrane of the epithelium of Sepia integument through a secondary active mechanism. For leucine, a 90% inhibition of the uptake was recorded in the presence of a large excess of the substrate. In agreement with the autoradiography results, an analysis of the cation specificity transport in BBMV showed that leucine uptake had a low cation specificity, whereas lysine and proline uptakes were Na+-dependent. An excess of lysine and proline, which share with alanine two different transport systems in the gill epithelium of marine bivalves, reduced eucine uptake. The possible role of the absorptive ability of the integument in a carnivorous mollusc is discussed.

Lipopolysaccharide-dependent induction of leech leukocytes that cross-react with vertebrate cellular differentiation markers

We have designed experiments to characterise leech leukocytes that mediate inflammatory responses. Shortly after inflicting injury to the body wall in the presence of lipopolysaccharides, many cells resembling macrophages, NK cells and granulocytes of vertebrates and many invertebrates migrated to the lesioned area. Nuclei of migrating cells incorporated bromodeoxyuridine. Using human monoclonal antibodies, macrophage-like cells were positive for CD25, CD14, CD61, CD68, CD11b and CD11c. NK-like cells were positive for CD25, CD56, CD57 and CD16, and granulocytes were positive for CD11b and CD11c. In blots of leech extracts, the CD25 monoclonal antibody recognised a band of about 55 kD; the CD56 monoclonal antibody, two bands of about 140 and 210 kD; the CD57 monoclonal antibody, two bands of about 106 and 70 kD; the CD14 monoclonal antibody, a band of about 50 kD; the CD16 monoclonal antibody, a band of about 60 kD. CD61 and CD68 both recognised a band of about 110 kD; CD11b recognised a band of 200 kD, and CD11c, a band of 180 kD.

Cultured granule cells and astrocytes from cerebellum differ in metabolizing sphingosine

Sphingosine metabolism was studied in primary cultures of differentiated cerebellar granule cells and astrocytes. After a 2-h pulse with [C3-(3)H]sphingosine at different doses (0.1-200 nmol/mg of cell protein), both cell types efficiently incorporated the long chain base; the percentage of cellular [(3)H]sphingosine over total label incorporation was extremely low at sphingosine doses of <10 nmol/mg of cell protein and increased at higher doses. Most of the [(3)H]sphingosine taken up underwent metabolic processing by N-acylation, 1-phosphorylation, and degradation (assessed as (3)H(2)O released in the medium). The metabolic processing of exogenous sphingosine was extremely efficient in both cells, granule cells and astrocytes being able to metabolize, respectively, an amount of sphingosine up to 80- and 300-fold the cellular content of this long chain base in 2 h. At the different doses, the prevailing metabolic route of sphingosine was different. At lower doses and in a wide dose range, the major metabolic fate of sphingosine was N-acylation. With increasing doses, there was first increased sphingosine degradation and then increased levels of sphingosine-1-phosphate. The data demonstrate that, in neurons and astrocytes, the metabolic machinery devoted to sphingosine processing is different, astrocytes possessing an overall higher capacity to synthesize the bioactive compounds ceramide and sphingosine-1-phosphate.

Identification and expression of NEU3, a novel human sialidase associated to the plasma membrane

Several mammalian sialidases have been described so far, suggesting the existence of numerous polypeptides with different tissue distributions, subcellular localizations and substrate specificities. Among these enzymes, plasma-membrane-associated sialidase(s) have a pivotal role in modulating the ganglioside content of the lipid bilayer, suggesting their involvement in the complex mechanisms governing cell-surface biological functions. Here we describe the identification and expression of a human plasma-membrane-associated sialidase, NEU3, isolated starting from an expressed sequence tag (EST) clone. The cDNA for this sialidase encodes a 428-residue protein containing a putative transmembrane helix, a YRIP (single-letter amino acid codes) motif and three Asp boxes characteristic of sialidases. The polypeptide shows high sequence identity (78%) with the membrane-associated sialidase recently purified and cloned from Bos taurus. Northern blot analysis showed a wide pattern of expression of the gene, in both adult and fetal human tissues. Transient expression in COS7 cells permitted the detection of a sialidase activity with high activity towards ganglioside substrates at a pH optimum of 3.8. Immunofluorescence staining of the transfected COS7 cells demonstrated the protein's localization in the plasma membrane.

Evidence that ganglioside enriched domains are distinct from caveolae in MDCK II and human fibroblast cells in culture

Cultures of MDCK II and human fibroblast cells were fed radioactive sphingosine and a radioactive GM3 ganglioside derivative containing a photoactivable group. The derived cell homogenates were treated with Triton X-100 and fractionated by sucrose-gradient centrifugation to prepare a detergent-insoluble membrane fraction known to be enriched in sphingolipid and caveolin-1, i.e. of caveolae. The detergent-insoluble membrane fraction prepared after feeding [1-3H]sphingosine to cells, was found to be highly enriched, with respect to protein content, in metabolically radiolabeled sphingomyelin and glycosphingolipids (about 18-fold). By feeding cells photoactivable radioactive GM3, after 2 h-chase, caveolin-1, CAV1, and proteins of high molecular mass became cross-linked to GM3, the cross-linking complexes being highly concentrated in the detergent-insoluble membrane fraction. The interaction between the ganglioside derivative and CAV1 was a time-dependent, transient process so that CAV1 cross-linking to GM3 was hardly detectable after a 24-h chase followed the pulse time. After a 24-h chase, only the high molecular mass proteins cross-linked to GM3 could be clearly observed. These results suggest that a portion of the GM3 administered to cells enters caveolae and moves to the glycosphingolipid domains, or enters caveolae that are then rapidly catabolized. Electron microscopy of cells in a culture immunostained with a monoclonal antibody to GM3 and a secondary gold-conjugated antibody detected several clusters of gangliosides on the plasma membranes separate from caveolae; gangliosides located inside the caveolae could not be detected. Scanning confocal microscopy of cells immunostained with anti-GM3 and anti-CAV1 Ig showed only a very small overlap with the CAV1 and GM3 signals. Thus, the biochemical and microscopic studies suggest that caveolae contain at most a low level of gangliosides and are separate from the GM3 ganglioside enriched domains.

Membrane anchoring and surface distribution of glycohydrolases of human erythrocyte membranes

The membrane anchoring of the following glycohydrolases of human erythrocyte plasma membranes was investigated: alpha- and beta-D-glucosidase, alpha- and beta-D-galactosidase, beta-D-glucuronidase, N-acetyl-beta-D-glucosaminidase, alpha-D-mannosidase, and alpha-L-fucosidase. Optimized fluorimetric methods for the assay of these enzymes were set up. Treatment of the ghost preparation with 1.0 mol/l (optimal concentration) NaCl caused release ranging from 4.2% of alpha-D-glucosidase to 70% of beta-D-galactosidase; treatment with 0.4% (optimal concentration) Triton X-100 liberated 5.1% of beta-D-galactosidase to 89% of alpha-D-glucosidase; treatment with 1.75% (optimal concentration) octylglucoside yielded solubilization from 6.3% of beta-D-galactosidase to 85% of alpha-D-glucosidase. Treatment with phosphoinositide-specific phospholipase C caused no liberation of any of the studied glycohydrolases. These results are consistent with the notion that the above glycohydrolases are differently anchored or associated with the erythrocyte plasma membrane, and provide the methodological basis for inspecting the occurrence of these enzymes in different membrane microdomains.

Sphingolipid-enriched membrane domains from rat cerebellar granule cells differentiated in culture. A compositional study

Sphingolipid-enriched membrane domains, characterized by a particular protein and lipid composition, have been detected in a variety of cells. However, limited data are available concerning these domains in neuronal cells. We analyzed the lipid and protein composition of a sphingolipid-enriched membrane fraction prepared from primary rat cerebellar granule cells differentiated in culture. Although the protein content of this fraction was only 1.4% of total cellular protein, 60% of the gangliosides, 67% of the sphingomyelin, 50% of the ceramide, and 40% of the cholesterol were located in this fraction. The protein pattern of the sphingolipid-enriched domain fraction was dramatically different from that associated with the cell homogenate. This fraction contained 25% of the tyrosine-phosphorylated proteins and was enriched in two proteins with apparent molecular masses of 135 and 15 kDa. 12% of cellular glycerophospholipids were located in the fraction, with phosphatidylcholine having the highest enrichment. The molar ratio between proteins, glycerophospholipids, cholesterol, sphingomyelin, ceramide and gangliosides in cerebellar granule cells was 1.6:41.6:6. 1:1.3:0.3:1 in the cell homogenate and 0.04:8.3:4.0:1.4:0.2:1 in the sphingolipid-enriched membrane fraction. These data indicate that selected proteins segregate with sphingolipids in specialized domains in the membrane of cultured neurons.

Association of Src-family protein tyrosine kinases with sphingolipids in rat cerebellar granule cells differentiated in culture

Src family kinases play a relevant role in the development and differentiation of neuronal cells. They are abundant in sphingolipid-enriched membrane domains of many cell types, and these domains are hypothesized to function in bringing together molecules important to signal transduction. We studied the association of Src family tyrosine kinases and their negative regulatory kinase, Csk, with sphingolipids in sphingolipid-enriched domains of rat cerebellar granule cells differentiated in culture. We find that c-Src, Lyn and Csk are enriched in the sphingolipid-enriched fraction prepared from these cells. Coimmunoprecipitation experiments show that these and sphingolipids are part of the same domain. Cross-linking experiments with a photoactivable, radioactive GD1b derivative show that c-Src and Lyn, which are anchored to the membrane via a myristoyl chain, associate directly with GD1b. Csk, which is not inserted in the hydrophobic core of the membrane, is not photolabeled by this ganglioside. These results suggest that lipid-lipid, lipid-protein, and protein-protein interactions cooperate to maintain domain structure. We hypothesize that such interactions might play a role in the process of neuronal differentiation.

New approaches to the study of sphingolipid enriched membrane domains: the use of electron microscopic autoradiography to reveal metabolically tritium labeled sphingolipids in cell cultures

This paper is the first report on the use of the electron microscopy autoradiography technique to detect metabolically tritium labeled sphingolipids in intact cells in culture. To label cell sphingolipids, human fibroblasts in culture were fed by a 24 hours pulse, repeated 5 times, of 3 x 10(-7) M [1-(3)H]sphingosine. [1-(3)H]sphingosine was efficently taken up by the cells and very rapidly used for the biosynthesis of complex sphingolipids, including neutral glycolipids, gangliosides, ceramide and sphingomyelin. The treatment with [1-(3)H]sphingosine did not induce any morphological alteration of cell structures, and well preserved cells, plasma membranes, and intracellular organelles could be observed by microscopy. Ultrathin sections from metabolic radiolabeled cells were coated with autoradiographic emulsion. One to four weeks of exposition resulted in pictures where the location of radioactive sphingolipids was evidenced by the characteristic appearance of silver grains as irregular coiled ribbons of metallic silver. Radioactive sphingolipids were found at the level of the plasma membranes, on the endoplasmic reticulum and inside of cytoplasmic vesicles. Thus, electron microscopy autoradiography is a very useful technique to study sphingolipid-enriched membrane domain organization and biosynthesis.

Different types of response to foreign antigens by leech leukocytes

We used morphological and immunocytochemical approaches to characterize and to show the behavior of cells involved in leech inflammatory responses. Leeches were injected with bacterial lipopolysaccharide, fluoresceinated yeasts, sulfate spheres and ciliates (Protozoa). Shortly after injection, migrating cells appeared in the area of injection. The response of the cells occurred in relation to the injected micro or macro antigens. Each injection first provoked a migration of cells towards the non-self material. Afterwards, different responses (degranulation, phagocytosis, encapsulation, melanization) occurred. The migrating cells involved in these series of processes have a similar behavior and are characterized by CD markers of macrophages, NK cells and granulocytes, which are typical of many invertebrates and vertebrates.