Identification of bovine doppel protein in testis, ovary and ejaculated spermatozoa

Doppel (Dpl) protein is a recently identified prion-like protein. Although Dpl might be expressed in the brain after prion gene deletion, in both human and mice Dpl is normally expressed only in testis and spermatozoa, where it appears to be involved in male fertility. Little information is available so far about the expression pattern of Dpl in bovines, thus, hampering possible research on the role of this protein in bovine infertility. We have thus, designed, produced and validated through Western blotting a polyclonal antibody against bovine Dpl. With this antibody we then screened bovine tissues for Dpl expression by immunohistochemistry. Ejaculated spermatozoa were screened by flow cytometry and immunocytochemistry. Bovine Dpl was expressed in all the developing stages of germinal cells, from spermatogones to ejaculated spermatozoa, in Sertoli cells and in ovarian follicles (granulosa cells and follicular fluid). Dpl immunoreactivity was also found on other tissues, where endothelial cells, peripheral nerves and scattered lymphocytes stained positive. This distribution pattern suggests that Dpl might be involved in sperm maturation/capacitation in bovines, like it might be in mice. This hypothesis needs to be verified by widespread application of the flow cytometric protocol established in this paper on spermatozoa from animals with reduced fertility

The acute phase protein α1-acid glycoprotein : a model for altered glycosylation during diseases

Glycosylation is one of the most important post-translational modifications of proteins, and has been widely acknowledged as one of the most important ways to modulate both protein function and lifespan. The acute phase proteins are a major group of serum proteins whose concentration is altered during various pathophysiological conditions. The aim of this paper is to review the structure and functions of the α1-acid glycoprotein (AGP). AGP belongs to the subfamily of immunocalins, a group of binding proteins that also have immunomodulatory functions. One of the most interesting features of AGP is that its glycosylation microheterogeneity can be modified during diseases. This aspect is particularly remarkable, since both the immunomodulatory and the binding properties of AGP strongly depend on its carbohydrate composition. For these reasons, AGP can be considered an outstanding model for the study of glycan pattern modification during diseases. This review is focused on the most recent studies on the occurrence of different glycoforms in plasma and tissues and how the appearance of different oligosaccharide patterns during systemic inflammation or diseases can influence AGP's biological functions. The first part of the review will describe the structure of AGP and the several biological functions identified so far for this protein. The second part will be devoted to the post-translational modifications of the oligosaccharides micro-heterogeneity of AGP caused by pathological states. A critical evaluation of the impact of different AGP glycoforms on both its transport and anti-inflammatory features, and how the modifications of the glycan pattern can be utilized in clinical biochemistry, is also discussed

Identification of the bovine alpha 1- acid glycoprotein in colostrum and milk

The acute phase protein alpha1-acid glycoprotein (AGP) is an immunomodulatory protein expressed by hepatocytes in response to the systemic reaction that follows tissue damage caused by inflammation, infection or trauma. AGP features at least two different biological activities, apparently very different each from the other: AGP may immunomodulate the inflammatory response, and, meanwhile, act as a plasma transport protein. As the other acute phase proteins, AGP is produced mainly by hepatic cells, but local expression has been reported in human breast epithelial cells, stimulated alveolar macrophages and human endothelial cells. The detection of two of the major bovine APP, haptoglobin and serum amyloid A (SAA) in milk during mastitis may suggest a role for APP also in the immunomodulation of local inflammatory reaction in the udder. This communication presents the detection of the bovine AGP(boAGP) in mammary secretions (colostrum and milk) and mammary gland tissue

Decreased sialylation of the Acute phase protein alpha-1-acid glycoprotein in feline infectious peritonitis (FIP)

Feline infectious peritonitis (FIP) is an immune-mediated disease of domestic and exotic felides infected with feline coronavirus. FIP is characterized by the overexpression of an acute phase protein, the \u3b11-acid glycoprotein (AGP). In humans, AGP is a heavily glycosylated protein that undergoes several modifications of its glycan moiety during acute and chronic inflammatory pathologies. We studied the changes in AGP glycosylation in the course of FIP. Specifically, we focussed our attention on the degree of sialylation, fucosylation and branching. This study presents a purification method for feline AGP (fAGP) from serum, using an ion exchange chromatography strategy. The glycosylation pattern was analyzed in detail by means of interaction of purified fAGP with specific lectins. In particular, Sambucus nigra agglutinin I and Maackia amurensis agglutinin lectins were used to detect sialic acid residues, Aleuria aurantia lectin was used to detect L-fucose residues and Concanavalin A was used to evaluate the branching degree. By this method we showed that fAGP did not present any L-fucose residues on its surface, and that its branching degree was very low, both in normal and in pathological conditions. In contrast, during FIP disease, fAGP underwent several modifications in the sialic acid content, including decreased expression of both \u3b1(2-6)-linked and \u3b1(2-3)-linked sialic acid (76 and 44%, respectively when compared to non-pathological feline AGP)

Production of IFN-γ in feline whole blood after incubation with potential T-cell epitopes of the nucleocapsid protein of feline coronavirus

Interferon gamma (IFN-γ) plays an important role in cell mediated responses against mutated feline coronavirus strains (FCoV) involved in the pathogenesis of feline infectious peritonitis (FIP). The aim of this study was to establish a combined in silico and in vitro approach to assess feline leukocyte production of IFN-γ in response to selected peptides of the nucleocapside protein (N) of FCoVs. To this aim, we designed, through a bioinformatic approach, 8 potentially immunogenic peptides from the protein N corresponding to sequences of residues 14, 182, 198 detected only in FCoVs from FIP cats (virulent strains), only in FCoVs from healthy cats (avirulent strains) and both in FIP and in healthy cats (mixed strains).The peptides or a sham solution were incubated with whole blood from 16 cats (7 healthy and 9 with chronic diseases other than FIP) and IFN-γ concentration was measured on plasma using an ELISA system. RT-PCR expression of IFN-γ mRNA was also evaluated after incubation of the peptides or a sham solution with whole blood from 4 clinically healthy cats. The mean plasma concentration of IFN-γ in samples incubated with peptides decreased and the expression of IFN-γmRNA did not change compared with the sham solution, except for some cats with chronic diseases (which probably have a "pre-activated" immune response). These cats responded to "avirulent" or "mixed" peptides by increasing the concentration of IFN-γ and the expression of IFN-γ mRNA. The combined approach employed in this study allowed us to identify potentially immunogenic peptides of FCoV N protein that can modulate the production of IFN-γ especially in cats with a "pre-activated" cell mediated response

Analisi della espressione di citochine in monociti bovini isolati

Cells of monocyte lineage partecipate in immune response by processing and presenting antigens and by producing cytokines, membrane receptors and growth factors that modulate immune response. In order to study cellular interactions in the immune responses of cattles, it is necessary to set up reliable methods to a) obtain highly enriched mononuclear phagocytes populations and b) evaluate the expression ratio of the cyotkines involved in immune response. The present communication describes a method for purify the CD14+ cells from bovine blood, and a procedure to evaluate and quantify by Real Time PCR the espression of cytokines and membrane receptors that are most involved in the modulation of immune response, including IL-1, TNF-alpha, IL-8 receptor, IL-1 beta antagonist, CD18, using GAPDH as housekeeping gene. CD14+ cells have been purified by means of magnetic sorting. The expression of cytokines has been determined after mRNA extraction and reverse trascription using commercial standard procedures and Oligo dT primer. Real Time PCR has been carried out by means of SYBR GREEN technique on iCycler iQ Real-Time PCR Detection System. Relative quantitation of cytokines was calculated as an n-fold difference in transcription of the respective cytokines from control samples (2 - \u394\u394Ct), using GAPDH as housekeeping gene

Serum alpha1-acid glycoprotein (AGP) concentration in non-symptomatic cats with feline coronavirus (FCoV) infection

Previous studies have demonstrated that the concentration of \u3b11-acid glycoprotein (AGP) transiently increases in asymptomatic cats infected with feline coronavirus (FCoV). In order to establish whether these fluctuations depend on the FCoV status, the serum concentration of AGP and anti-FCoV antibody titres and/or faecal shedding of FCoVs in clinically healthy cats from catteries with different levels of prevalence of FCoV infection were monitored over time. Serum AGP concentrations fluctuated over time in clinically healthy cats from the cattery with the highest prevalence of feline infectious peritonitis (FIP) and significantly increased just before an outbreak of FIP. Further studies are required to clarify whether the observed increase of AGP concentration is a consequence of the increased viral burden or a protective response against mutated viral strains. Nevertheless, the results of the present study suggest that AGP might be useful in monitoring FCoV-host interactions in FCoV-endemic catteries

Alpha(1)-Acid glycoprotein modulates apoptosis in bovine monocytes

alpha(1)-Acid glycoprotein (AGP, orosomucoid) is a normal costituent of bovine blood. AGP is an immunocalin, a binding protein that can also exert several immunomodulatory functions. In this paper we investigated the effect of bovine alpha(1)-acid glycoprotein (boAGP) on spontaneous and staurosporine-induced apoptosis of blood derived monocytes purified using magnetic cell sorting techniques. Bovine AGP was purifed from blood following a chromatographic protocol. The homogeneous protein was used to stimulate the cells as well to raise a polyclonal antibody, that was used throughout all the experiments. When monocytes were incubated with high concentrations of boAGP (0.9 mg/ml), similar to those found in bovine plasma during systemic reaction to inflammation, their spontaneous apoptosis rate was suppressed, as determined by caspase-3/7 enzymatic activity assay. Similar results were obtained when apoptosis was induced by adding staurosporine, a potent protein kinase inhibitor. The apoptosis-modulating activity of boAGP was dependent on its concentration, since physiological concentrations of boAGP (0.3 mg/ml) did not exhibit a statistically significative anti-apoptotic activity. We also investigated whether this apoptosis-modulating activity was dependent on the terminal sialic acid residues exposed on the surface of the protein. Enzymatic treatment with neuraminidase, that cleaves terminal sialic acid residues, completely abolished boAGP's anti-apoptotic activity. These results suggest that the protective effect of AGP is likely mediated by its sialic acid terminal groups