Giuseppe Passantino

FISH IMMUNOLOGY. I. BINDING AND ENGULFMENT OF CANDIDA ALBICANS BY ERYTHROCYTES OF RAINBOW TROUT (SALMO GAIRDNERI RICHARDSON)

ABSTRACT The role of fish erythrocytes (FE) as phagocytic cells has poorly been investigated, until now. Here, we have focussed our attention on the interplay between rainbow trout (Salmo gairdneri Richardson) erythrocytes and Candida albicans (CA). At the same time, the intervention of autologous head kidney macrophages (MØ) in the CA processing by FE has been studied. Data show that CA particles bind to FE, which, in turn, are able to engulf but not kill them. In the presence of MØ, a decrease of FE with bound CA occurs and, in some microscopic images, FE form rosettes with MØ. Phagocytosis of CA is higher in rosetting MØ than in non-rosetting ones. According to our findings, it appears that FE represent a reservoir of engulfed CA and rosetting is an efficacious phenomenon of presentation of pathogens to MØ, where an effective clearance of them can take place.

Do Fish Thrombocytes Play an Immunological Role? Their Cytoenzymatic Profiles and Function During an Accidental Piscine Candidiasis in Aquarium

Fish (F) thrombocytes (THRs) from healthy trouts were studied in terms of cytoenzyme expression. FTHRs were positive to acid periodic of shiff (PAS) and acid phosphatase (ac. phos.) without tartaric acid (− TA) stainings, as well to alkaline phosphatase. However, when compared with autologous macrophages (MØs), they were negative to naphthol cloroacetate esterase (AS-D), α-naphthyl acetate esterase (Anae), peroxidase (perox) and control ac. phos. with tartaric acid (+ TA) stainings, thus indicating a lack of typical lysosomial enzymes. This evidence supports the notion that FTHRs are not true digesting cells. Quite interestingly, trouts and human MØs were positive for PAS, AS-D, Anae, and perox stainings, thus confirming that cellular cytochemistries are maintained across evolution as their phagocytic functions. Additionally, blood films from trouts, accidentally infected with Candida albicans in aquarium, were morphologically analyzed. Actually, FTHRs interact with erythrocytes, potentiating the formation of rosettes around a central MØ. Polymorph nuclear cells and lymphocytes are present in these cellular aggregates, thus suggesting that FTHRs may represent a link between innate and adaptive immunity.

Maturation of fish erythrocytes coincides with changes in their morphology, enhanced ability to interact with Candida albicans and release of cytokine-like factors active upon autologous macrophages.

Erythrocytes from the rainbow trout Salmo gairdneri Richardson (Salmo g.R.) were classified into immature and mature populations, respectively, by measuring longitudinal diameters. More elongated fish erythrocytes (FE), classified as mature cells, were those interacting with Candida albicans (CA) in a higher frequency in terms of either binding to the fungus or its intracellular engulfment. At the same time, in the rosetting phenomenon more elongated mature FE surrounded macrophages (MØ) phagocytosing CA. Finally, FE activated by CA released in the supernatants cytokine‐like factors able to modulate MØ functions. In particular, these active supernatants were analyzed for their capacity to inhibit MØ migration Macrophage Inhibition Factor (MIF) activity and enhance MØ phagocytosis. Both activities were detected in supernatants from CA stimulated FE but not in control supernatants. MIF activity could play a role in the accumulation of MØ in the context of functional rosettes, while the factor enhancing MØ phagocytosis could promote clearance of CA in a more efficacious way.

Antigenically Activated Avian Erythrocytes Release Cytokine-Like Factors: A Conserved Phylogenetic Function Discovered in Fish

Fish erythrocytes are endowed with the ability to produce cytokine like factors when stimulated with Candida albicans (Ca). To evaluate whether similar activities are still conserved in bird erythrocytes (BE), a morphological, cytochemical and immunological evaluation was conducted on peripheral cells in chickens (Gallus gallus). BE form rosettes with monocytes (Mo)-macrophages (MØ), and Mo-MØ according to cytochemical analysis to maintain phagocytic functions across the evolution. Finally, Ca-activated BE release in the supernatants cytokine like-factors that enhance Mo-MØ phagocytosis (interferon-γ-like activity) and inhibit Mo-MØ migration in agarose (migration inhibitory factor activity). In conclusion, bird erythrocytes, as nonimmune cells, are able to participate in the immune response contributing to the host defence.

Pathological and histological findings associated with the feline lungworm Troglostrongylus brevior

Troglostrongylus brevior is a neglected feline lungworm species, which has been increasingly reported in the Mediterranean area, although scant data are available on the respiratory alterations it causes in cats. Therefore, we describe the gross and histological lesions of a 20-week old kitten that succumbed due to the onset of a fulminant respiratory failure. At necropsy, a catarrhal exudate was observed in the airways, along with nematodes in the trachea and bronchi. The lungs were processed for histological examination and serial pulmonary sections were performed. A total of 14 nematodes were collected, being all morphologically and molecularly identified as T. brevior. Lungworms were histologically localized within the bronchial lumen, surrounded by an eosinophilic infiltrate. The presence of T. brevior in the airways has been histologically documented for the first time and its life-threatening potential is discussed.

Lymphoreticular System in Fish: Erythrocyte-Mediated Immunomodulation of Macrophages Contributes to the Formation of Melanomacrophage Centers

In fish, melanomacrophage centers (MMC) represent the equivalent of germinal centers of birds and mammals. They consist of aggregates of macrophages filled with fragments of cells, mainly erythrocytes, and various pigments such as hemosiderin, lipofuscin, and melanin. The kidney, the spleen, and the liver contain many MMC either moving freely or encapsulated in the context of the lymphoreticular tissue. Here, we have demonstrated for the first time that MMC exist in the kidney, spleen, and liver of the rainbow trout Salmo gairdneri Richardson by using traditional stainings and cytoenzymatic methods: periodic acid-shiff, α-naphthyl acetate esterase, and peroxidase. Finally, in the view of the already described peripheral interaction between fish erythrocytes (FE) and macrophages (MØ), we postulate that these cellular aggregates (rosettes) travel to distant organs, thus contributing to the formation of MMC in the kidney, spleen, and liver.

Expression of proto-oncogene C-kit and correlation with morphological evaluations in canine cutaneous mast cell tumors.

Canine cutaneous mast cell tumor (MCT) is very common disease in dogs, this is more aggressive than in other species. The biologic behavior of MCT is highly variable and a more accurate prognosis for these tumors needs to performed. The proto-oncogene c-kit is known to play a critical role in development and function of mast cells (MC). The aim of this study was to evaluate the expression of immunohistochemical pattern of c-kit in MCTs and to correlate these results with MC density (MCD) and intratumoral microvessel density (MVD). Our results confirm that a more aggressive biologic behavior of canine MCT is associated with the increased c-kit expression, further suggesting a new role for c-kit, as a useful marker, in diagnostic pathology and in tumor progression.

In Vitro Elicitation of Intestinal Immune Responses in Teleost Fish: Evidence for a Type IV Hypersensitivity Reaction in Rainbow Trout

In fish the gut immune system has been the subject of few investigations until now. Here, we provide novel morphological and immunological data on the gut isolated from rainbow trout Salmo gairdneri. The pyloric (P) and terminal (T) segments of trout gut, when morphologically examined, evidenced lymphocytes and macrophages (MØ) loosely dispersed in the intestinal mucosa and in the lamina propria in the absence of typical Peyers patches-like structures. Furthermore, incubation of P and T sections with Candida albicans (Ca) and functional analysis of supernatants generated some interesting results. In fact, active supernatants, when compared with controls, exhibited cytokine-like activities attributable to the presence of interferon (IFN)-γ and migration inhibiting factor (MIF), respectively. In particular, IFN-γ-like activity gave rise to an enhancement of Ca phagocytosis by MØ, whereas MIF inhibited MØ migration in agarose. Taken together, these in vitro data suggest that the gut-associated lymphoreticular tissue in fish possesses the appropriate armamentarium to mount a type IV hypersensitivity response when challenged by microbial antigens.

ATP Sensitive Potassium Channels in the Skeletal Muscle Function: Involvement of the KCNJ11(Kir6.2) Gene in the Determination of Mechanical Warner Bratzer Shear Force

The ATP-sensitive K+-channels (KATP) are distributed in the tissues coupling metabolism with K+ ions efflux. KATP subunits are encoded by KCNJ8 (Kir6.1), KCNJ11 (Kir6.2), ABCC8 (SUR1), and ABCC9 (SUR2) genes, alternative RNA splicing give rise to SUR variants that confer distinct physiological properties on the channel. An high expression/activity of the sarco-KATP channel is observed in various rat fast-twitch muscles, characterized by elevated muscle strength, while a low expression/activity is observed in the slow-twitch muscles characterized by reduced strength and frailty. Down-regulation of the KATP subunits of fast-twitch fibers is found in conditions characterized by weakness and frailty. KCNJ11 gene knockout mice have reduced glycogen, lean phenotype, lower body fat, and weakness. KATP channel is also a sensor of muscle atrophy. The KCNJ11 gene is located on BTA15, close to a QTL for meat tenderness, it has also a role in glycogen storage, a key mechanism of the postmortem transformation of muscle into meat. The role of KCNJ11 gene in muscle function may underlie an effect of KCNJ11 genotypes on meat tenderness, as recently reported. The fiber phenotype and genotype are important in livestock production science. Quantitative traits including meat production and quality are influenced both by environment and genes. Molecular markers can play an important role in the genetic improvement of animals through breeding strategies. Many factors influence the muscle Warner-Bratzler shear force including breed, age, feeding, the biochemical, and functional parameters. The role of KCNJ11gene and related genes on muscle tenderness will be discussed in the present review.

First observation of an Hashimoto thyroiditis-like disease in horses from Eastern Europe: histopathological and immunological findings.

Among 622 slaughtered horses from eastern Europe, 156 thyroid glands were selected on the basis of macroscopic alterations (e.g., determination of volume and weight). In the 80% of these thyroids, microscopic alterations consistent with a diagnosis of Hashimoto thyroiditis-like disease were found. In particular, a subverted architecture of the thyroid gland with colloid rarefaction, lymphocytic infiltration, and fibrosis was noted. The confirmation of the histopathological diagnosis of an equine Hashimoto thyroiditis-like disease was provided by the increased serum concentration of thyroglobulin, of antithyroglobulin, and of antithyroid peroxidase autoantibodies. Despite evidence consistent with an Hashimoto thyroiditis-like disease in eastern European horses, the etiopathogenesis of this autoimmune disorder deserves further investigation. In this respect, in some horses histopathological alterations in the pituitary gland may suggest an as-yet-unidentified disorder within the hypothalamus-pituitary adrenal axis associated with Hashimoto thyroiditis.