Variability in the Response against Teladorsagia circumcincta in Lambs of Two Canarian Sheep Breeds.

The increasing resistance to anthelmintics has necessitated the exploration of alternative control strategies of gastrointestinal nematode (GIN) infections. A sustainable option is genetic selection based on differences in susceptibility to GIN infection between and within breeds of sheep. Here, three-month-old Canaria Hair breed (GIN-resistant) and Canaria Sheep breed (GIN-susceptible) showed no significant between-breed differences after trickle infection with Teladorsagia circumcincta, whereas considerable individual variability was found in both breeds. Next, data from lambs of both breeds were used to explore the relationships between parasitological variables and T. circumcincta-specific IgA levels, local immune cell populations, and abomasal lymph node gene expression to understand the possible mechanisms underlying resistance. Mucosal IgA levels as well as numbers of globular leukocytes and MHC-II+ cells were associated with protection. Analysis of lymph node gene expression revealed the associations between lower parasite numbers and cumulative fecal egg counts and several immune pathways, such as leukocyte cell adhesion, activation and differentiation of T cells, in particular CD4+ and IL-4 production. The data obtained here may inform on the relationship between phenotypic resistance variability and protective responses at the humoral, cellular, and transcriptomic levels, thus contributing to identifying immune responses in young lambs that could be used as markers for selection.

Cellular and humoral immune responses associated with protection in sheep vaccinated against Teladorsagia circumcincta.

Due to increased anthelmintic resistance, complementary methods to drugs are necessary to control gastrointestinal nematodes (GIN). Vaccines are an environmentally-friendly and promising option. In a previous study, a Teladorsagia circumcincta recombinant sub-unit vaccine was administered to two sheep breeds with different levels of resistance against GIN. In the susceptible Canaria Sheep (CS) breed, vaccinates harboured smaller worms with fewer eggs in utero than the control group. Here, we extend this work, by investigating the cellular and humoral immune responses of these two sheep breeds following vaccination and experimental infection with T. circumcincta. In the vaccinated CS group, negative associations between antigen-specific IgA, IgG2 and Globule Leukocytes (GLs) with several parasitological parameters were established as well as a higher CD4+/CD8+ ratio than in control CS animals, suggesting a key role in the protection induced by the vaccine. In the more resistant Canaria Hair Breed (CHB) sheep the vaccine did not significantly impact on the parasitological parameters studied and none of these humoral associations were observed in vaccinated CHB lambs, although CHB had higher proportions of CD4+ and CD8+ T cells within the abomasal lymph nodes, suggesting higher mucosal T cell activation. Each of the component proteins in the vaccine induced an increase in immunoglobulin levels in vaccinated groups of each breed. However, levels of immunoglobulins to only three of the antigens (Tci-MEP-1, Tci-SAA-1, Tci-ASP-1) were negatively correlated with parasitological parameters in the CS breed and they may be, at least partially, responsible for the protective effect of the vaccine in this breed. These data could be useful for improving the current vaccine prototype.

Differences within Churra breed sheep in the early immune response to the infection by Teladorsagia circumcincta.

This study describes early immunological mechanisms that underlie resistance to Teladorsagia circumcincta infection in adult Churra sheep. After a first experimental infection, 6 animals were classified as resistant (RG) and 6 as susceptible (SG) to T. circumcincta infection based on their cumulative faecal egg count (cFEC) at the end of the infection. RG showed higher IgA levels against somatic antigen of T. circumcincta fourth-larvae stage (L4) in serum at day 3 post-infection (pi) (p < 0.05) and close to significance at day 21 pi (p = 0.06). Moreover, a strong negative correlation between cFEC and specific IgA was only significant in RG at day 3 pi (r = - 0.870; p < 0.05), but absent in SG. At the end of this infection, sheep were treated with moxidectin and infected again 3 weeks later to be slaughtered at day 7 pi. At necropsy, the specific IgA levels in gastric mucosa were similar between groups; the absence differences at day 7 pi could be due to a previous increase in the IgA response, probably around day 3 pi, as described during the first infection. L4 burden, 68% lower in RG than in SG, was influenced by the specific IgA in gastric mucus and the number of γδ T cells. RG group showed a positive correlation between γδ T cells and eosinophils (r = 0.900; p = 0.037); however, this correlation was not found in SG. These results show that these two phenotypes show different early immune response pattern to T. circumcincta infection in Churra sheep.

Increased susceptibility to Haemonchus contortus infection by interleukin-5 modulation of eosinophil responses in sheep.

Eosinophils are prominent effector cells in immune responses against gastrointestinal nematode infections in ruminants, but their in vivo role has been hard to establish in large animals. Interleukin-5 is a key cytokine in the induction and stimulation of anti-parasitic eosinophil responses. This study attempted to modulate the eosinophil response in sheep through vaccination with recombinant interleukin-5 (rIL-5) and determine the effect on subsequent Haemonchus contortus infection. Nematode-resistant Canaria Hair Breed (CHB) sheep vaccinated with rIL-5 in Quil-A adjuvant, had lower blood eosinophil counts and higher mean worm burdens than control sheep vaccinated with Quil-A adjuvant alone. In addition, adult worms in IL-5-vaccinated sheep were significantly longer with higher eggs in utero in female worms, supporting an active role of eosinophils against adult parasites in CHB sheep. These results confirm that eosinophils can play a direct role in effective control of H contortus infection in sheep and offer a new approach to study immune responses in ruminants.

Impacts of breed type and vaccination on Teladorsagia circumcincta infection in native sheep in Gran Canaria.

Vaccines and genetic resistance offer potential future alternatives to the exclusive use of anthelmintics to control gastrointestinal nematodes (GIN). Here, a Teladorsagia circumcincta prototype vaccine was administered to two sheep breeds which differ in their relative levels of resistance to infection with GIN. Vaccination of the more susceptible Canaria Sheep (CS) breed induced significant reductions in worm length and numbers of worm eggs in utero (EIU) when compared to control CS sheep. In the more resistant Canaria Hair Breed (CHB), although vaccination induced a reduction in all parasitological parameters analysed, differences between vaccinated and control sheep were not statistically significant. Such interactions between sheep breed and vaccination may allow better integrated control of GIN in future.

Exploring the transcriptomic changes underlying recombinant vaccine efficacy against Teladorsagia circumcincta in 3-month-old lambs.

Teladorsagia circumcincta is an abomasal parasitic nematode that can cause serious issues in small ruminant production, which are aggravated by drug resistance. Vaccines have been suggested as a feasible, long-lasting alternative for control since adaptation to the host's immune mechanisms by helminths develops at a much slower pace than anthelmintic resistance. Recently, a T. circumcincta recombinant subunit vaccine yielded over a 60% reduction in egg excretion and worm burden and induced strong humoral and cellular anti-helminth responses in vaccinated 3-month-old Canaria Hair Breed (CHB) lambs, but Canaria Sheep (CS) of a similar age were not protected by the vaccine. Here, we compared the transcriptomic profiles in the abomasal lymph nodes of such 3-month-old CHB and CS vaccinates 40 days after infection with T. circumcincta to understand differences in responsiveness at the molecular level. In the CS, differentially expressed genes (DEG) identified were related to general immunity processes such as antigen presentation or antimicrobial proteins and down-regulation of inflammation and immune response through regulatory T cell-associated genes. However, upregulated genes in CHB vaccinates were associated with type-2 oriented immune responses, i.e., immunoglobulin production, activation of eosinophils, as well as tissue structure and wound repair-related genes and protein metabolism pathways such as DNA and RNA processing. These results highlight potentially more optimal timing and orientation of immune responses in CHB sheep compared to CS associated with vaccine-induced protection. The data obtained in this study thus deepens our understanding of variations in responsiveness to vaccination in young lamb and provides insights for vaccine refinement strategies.

Cetacean Intracytoplasmic Eosinophilic Globules: A Cytomorphological, Histological, Histochemical, Immunohistochemical, and Proteomic Characterization.

The nature, etiopathogenesis, and clinicopathologic relevance of the prevalent intracytoplasmic eosinophilic globules (IEGs) within hepatocytes of cetaceans are unknown. This study aims to evaluate the presence and characterize the IEGs in the hepatocytes of cetaceans using histochemical and immunohistochemical electron microscopy, Western blot, lectin histochemistry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry techniques. A total of 95/115 (83%) animals (16 species) exhibited histologically evident intracytoplasmic round to oval, single to multiple, hyaline eosinophilic globules within the hepatocytes. These globules were largely PAS-positive, diastase resistant, and were immunopositive for fibrinogen (FB, 97%), albumin (Alb, 85%), and α1-antitrypsine (A1AT, 53%). The IEG positivity for FB and A1AT were correlated with live-stranding, hepatic congestion and a good nutritional status. The cetaceans lacking IEGs were consistently dead stranded and had poor body conditions. The IEGs in 36 bycaught cetaceans were, all except one, FB-positive and A1AT-negative. The IEGs exhibited morphologic and compositional variations at the ultrastructural level, suggesting various stages of development and/or etiopathogenesis(es). The glycocalyx analysis suggested an FB- and A1AT-glycosylation pattern variability between cetaceans and other animals. The proteomic analyses confirmed an association between the IEGs and acute phase proteins, suggesting a relationship between acute stress (i.e., bycatch), disease, and cellular protective mechanisms, allowing pathologists to correlate this morphological change using the acute hepatocytic cell response under certain stress conditions.

Nematode galectin binds IgE and modulates mast cell activity.

Mast cell degranulation is the major mechanism influencing establishment and survival of the abomasal nematode Teladorsagia circumcincta and probably many other gastrointestinal nematodes. Host galectins-3 and -9 have been shown to bind IgE and positively and negatively influence mast cell degranulation. As incoming nematodes produce large amounts of galectin, we hypothesised that nematode galectin competes with host galectin and inhibits mast cell degranulation. ELISA was used to show that nematode galectin reduced total IgE activity. Galectin also reduced the binding of sheep IgE to the surface of a mast cell line and decreased the release of LCT-4 and Beta hexosaminidase but not MMP-9. These results indicate that nematode galectin influences mast cell degranulation and identify a potential immunomodulatory mechanism used by nematodes to enhance their establishment and survival.

Differences in the protection elicited by a recombinant Teladorsagia circumcincta vaccine in weaned lambs of two Canarian sheep breeds.

Gastrointestinal nematode (GIN) infections are a serious drawback on small ruminant production. Since anthelmintic resistance has extended, optimisation of alternative non-chemical control strategies has attracted interest. Recently, a prototype recombinant vaccine protected immunologically mature sheep from Texel-cross and Canaria Sheep breeds against Teladorsagia circumcincta. The level of protective immunity stimulated by the vaccine varied between individuals and with age. Previous studies suggest that Canaria Hair Breed (CHB) sheep is naturally resistant to GIN infection, with some evidence suggesting that this protection is present in young lambs. Here, we sought to enhance this resistance by immunising three-month-old CHB lambs with a T. circumcincta prototype recombinant vaccine. Following vaccination and a larval challenge period, levels of protection against T. circumcincta infection were compared in CHB lambs with Canaria Sheep (CS) lambs (a breed considered less resistant to GIN). Lambs from the resistant CHB breed appeared to respond more favourably to vaccination, shedding 63% fewer eggs over the sampling period than unvaccinated CHB lambs. No protection was evident in CS vaccinated lambs. At post-mortem, CHB vaccine recipients had a 68% reduction in mean total worm burden, and female worms were significantly shorter and contained fewer eggs in utero compared to unvaccinated CHB lambs. A higher anti-parasite IgG2 level was detected in immunised CHB lambs compared to unvaccinated control CHB animals, with data suggesting that IgA, globular leucocytes, CD45RA+, CD4+ and CD8+ T cells are implicated in this protective response. The development of effective immunity in vaccinated CHB lambs did not reduce lamb growth rate as immunised CHB lambs had a significantly higher average daily weight gain after challenge than their unvaccinated counterparts. Therefore, the protection of CHB lambs was enhanced by immunisation at weaning, suggesting a synergistic effect when combining vaccination with presumed genetic resistance.

The oligomeric assembly of galectin-11 is critical for anti-parasitic activity in sheep (Ovis aries).

Galectins are a family of glycan-binding molecules with a characteristic affinity for ß-D-glycosides that mediate a variety of important cellular functions, including immune and inflammatory responses. Galectin-11 (LGALS-11) has been recently identified as a mediator induced specifically in animals against gastrointestinal nematodes and can interfere with parasite growth and development. Here, we report that at least two natural genetic variants of LGALS-11 exist in sheep, and demonstrate fundamental differences in anti-parasitic activity, correlated with their ability to dimerise. This study improves our understanding of the role of galectins in the host immune and inflammatory responses against parasitic nematodes and provides a basis for genetic studies toward selective breeding of animals for resistance to parasites.

Modulation of Haemonchus contortus infection by depletion of γδ+ T cells in parasite resistant Canaria Hair Breed sheep.

Canaria Hair Breed (CHB) sheep display resistance against the adult stage of the nematode, Haemonchus contortus. Previous studies have suggested significant correlations between γδ+ T lymphocytes and fecundity of female adult worms, suggesting a novel role in immune modulation by these cells. The largest proportion of γδ+ T lymphocytes in sheep are the subpopulation of γδ+/WC1+ T cells. The aim of this study was to evaluate the effect of γδ+/WC1+ T cell depletion via infusion of anti-γδ/WC1 monoclonal antibody (mAb) on the subsequent immune response of CHB sheep infected with H. contortus. Significantly lower γδ+ T cell levels in both peripheral blood and in the basal layers of the abomasal tissue resulted following anti-γδ/WC1 mAb infusion of CHB sheep compared to control animals. Worms recovered from the anti-γδ/WC1 mAb treated CHB sheep had significantly longer female worms with correspondingly more eggs in utero than the saline control group. Significant correlations between eosinophils and worm length and fecundity were no longer apparent in the anti-γδ/WC1 mAb treated CHB sheep. These results support the notion that γδ+ T cells in CHB sheep play a critical role in fecundity regulation (length and eggs in utero) of H. contortus adult female worms, and highlights a new mechanism of modulation by this lymphocyte population, possibly involving eosinophil activation.

Epidemiological survey of zoonotic helminths in feral cats in Gran Canaria island (Macaronesian archipelago-Spain).

The presence of zoonotic parasites in feral cats have been widely considered all over the world. In Gran Canaria (Macaronesian archipelago, Canary Islands, Spain) the number of feral cats has grown out of control in urban and rural areas. 48 of Felis catus captured in different Gran Canaria areas were studied. Animals were necropsied and several organs were systematically examined in order to collect and identify macroscopic parasites. In addition, coprological tests were done in 28 cats. There were no statistically significant differences in the prevalence rate among sex, age or capture area, showing an overall prevalence of helminths of 77.1%. The most common tapeworms were Dipylidium caninum (64.6%) and Taenia taeniaeformis (31.3%), followed by the nematodes Toxocara cati (20.8%), Ancylostoma tubaeforme (18.8%), Aelurostrongylusabstrusus (10.4%) and Truchuris vulpis (2.08%). We also find several eggs of Alaria alata in the small intestine of one cat (2.08%), being the first description of this trematode in cats in the Canary Islands. Aproximatelly, 40% of the studied cats harboured more than one parasite. High rates of zoonotic species found in these animals suggest the need of controling parasitic infections and preventive measures against them.

Epidemiological survey of zoonotic helminths in feral cats in Gran Canaria island (Macaronesian archipelago-Spain).

The presence of zoonotic parasites in feral cats have been widely considered all over the world. In Gran Canaria (Macaronesian archipelago, Canary Islands, Spain) the number of feral cats has grown out of control in urban and rural areas. 48 of Felis catus captured in different Gran Canaria areas were studied. Animals were necropsied and several organs were systematically examined in order to collect and identify macroscopic parasites. In addition, coprological tests were done in 28 cats. There were no statistically significant differences in the prevalence rate among sex, age or capture area, showing an overall prevalence of helminths of 77.1%. The most common tapeworms were Dipylidium caninum (64.6%) and Taenia taeniaeformis (31.3%), followed by the nematodes Toxocara cati (20.8%), Ancylostoma tubaeforme (18.8%), Aelurostrongylusabstrusus (10.4%) and Trichuris vulpis (2.08%). We also find several eggs of Alaria alata in the small intestine of one cat (2.08%), being the first description of this trematode in cats in the Canary Islands. Aproximatelly, 40% of the studied cats harboured more than one parasite. High rates of zoonotic species found in these animals suggest the need of controling parasitic infections and preventive measures against them.

Possible mechanisms of host resistance to Haemonchus contortus infection in sheep breeds native to the Canary Islands.

Haemonchus contortus appears to be the most economically important helminth parasite for small ruminant production in many regions of the world. The two sheep breeds native to the Canary Islands display distinctly different resistant phenotypes under both natural and experimental infections. Canaria Hair Breed (CHB) tends to have significantly lower worm burden and delayed and reduced egg production than the susceptible Canaria Sheep (CS). To understand molecular mechanisms underlying host resistance, we compared the abomasal mucosal transcriptome of the two breeds in response to Haemonchus infection using RNAseq technology. The transcript abundance of 711 and 50 genes were significantly impacted by infection in CHB and CS, respectively (false discovery rate <0.05) while 27 of these genes were significantly affected in both breeds. Likewise, 477 and 16 Gene Ontology (GO) terms were significantly enriched in CHB and CS, respectively (P < 1.0 × 10(-4)). A broad range of mechanisms have evolved in resistant CHB to provide protection against the parasite. Our findings suggest that readily inducible acute inflammatory responses, complement activation, accelerated cell proliferation and subsequent tissue repair, and immunity directed against parasite fecundity all contributed to the development of host resistance to parasitic infection in the resistant breed.

Transfusión fetal intrauterina por hdrops fetal no inmune secundario a anemia por citomegalovirus / Intrauterine Fetal Transfusion non-immune Hydrops Fetales Secondary to Anemia b y Cytomegalovirus

La infección por citomegalovirus (CMV) es la infección congénita más común, con una incidencia de 0.2 a 2.2 % en los recién nacidos vivos. Del 10 al 15% del los recién nacidos infectados son sintomáticos. Los signos clínicos comunes son ictericia, petequias y hepatoesplenomegalia, además de prematuridad, trombocitopenia y anemia. Él diagnóstico fetal se sospecha por ultra - sonografía y se conirma mediante detección de Ig G en muestra tomadas atreves de cordocentesis o amniocentesis. Descripción del caso: Se presenta caso de una embarazada de 35 años de edad, a quien se le realizo a las 34.3 semanas de gestación cordo - centesis diagnostica, por presentar Hidrops fetal NO INMUNE mas anemia fetal severa diagnósticada por velocidad de pico sistólico de la arteria cerebral media, presentando características ultrasonografías, se realizó transfusión intrautero sin ninguna complicación además se llevó el embarazo al término, la evaluación oftalmológica reporto secuelas maculares características de citomegalovirus...(AU)