Cryopreservation of the bovine oocyte: current status and perspectives

This review presents some of the most noticeable aspects related with the oocyte cryopreservation procedures, emphasizing their evolution in the bovine, which points towards the critical points determining the reduced survival rates of female gametes to freezing and vitrification. Factors such as the maturation status, the cytoskeleton and membrane sensitivity, the role of the cumulus cells, the impact of the cryoprotectants agents and the protocols utilized and the future of this tool have been extensively reviewed.     

Vaccination against foot and mouth disease: current state and perspectives

Foot-and-mouth disease (FMD) is endemic in many parts of the world and poses a permanent threat for cloven-hoofed animals in all countries. The available vaccines against FMD are safe and efficacious. Combat of FMD by vaccination is controversial in currently FMD-free countries including the ones of the European Union. The article summarizes our knowledge concerning production and use of vaccines, virus persistence, differentiation between vaccinated and infected animals, vaccination programs and perspectives of vaccine development.     

DNA vaccines and their applications in veterinary practice: current perspectives

Inoculation of plasmid DNA, encoding an immunogenic protein gene of an infectious agent, stands out as a novel approach for developing new generation vaccines for prevention of infectious diseases of animals. The potential of DNA vaccines to act in presence of maternal antibodies, its stability and cost effectiveness and the non-requirement of cold chain have heightened the prospects. Even though great strides have been made in nucleic acid vaccination, still there are many areas that need further research for its wholesome practical implementation. Major areas of concern are vaccine delivery, designing of suitable vectors and cytotoxic T cell responses. Also, the induction of immune responses by DNA vaccines is inconclusive due to the lack of knowledge regarding the concentration of the protein expressed in vivo. Alternative delivery systems having higher transfection efficiency and the use of cytokines, as immunomodulators, needs to be further explored. Recently, efforts are being made to modulate and prolong the active life of dendritic cells, in order to make antigen presentation a more efficacious one. For combating diseases like acquired immunodeficiency syndrome (AIDS), influenza, malaria and tuberculosis in humans; and foot and mouth disease, Aujesky’s disease, swine fever, rabies, canine distemper and brucellosis in animals, DNA vaccine clinical trials are underway. This review highlights the salient features of DNA vaccines, and measures to enhance their efficacy so as to devise an effective and novel vaccination strategy against animal diseases.     

Rationale and perspectives on the success of vaccination against bovine herpesvirus-1

Several characteristics of BHV-1 have contributed to the successful development of both conventional and marker vaccines. BHV-1 is a stable virus, which grows to high titers in vitro, has a limited host range and causes acute viremic infections. Furthermore, the protective antigens, as well as the antigens that are suitable as marker, are present in the predominant virus isolates and induce significant and long-lasting immune responses, both in na?ve and in previously vaccinated animals. In many parts of the world including North-America control of BHV-1 is achieved by vaccination with conventional attenuated or inactivated vaccines. With parts of Europe being BHV-1 free, the ability to differentiate infected from vaccinated animals has become critical as a trading tool. Live and killed gE-deleted marker vaccines are now widely used in Europe, in combination with gE-based diagnostic tests to monitor cattle. However, several issues remain to be resolved. BHV-1 causes latency, which creates a need for stringent management practices in case eradication is to be achieved. Since intramuscular delivery with a syringe and needle leads to considerable tissue damage, needle-free delivery methods should be adopted for beef cattle. Furthermore, conventional inactivated and attenuated vaccines are less efficacious in neonates, so alternative vaccine types such as CpG adjuvanted protein vaccines or DNA vaccines are required for effective vaccination of this age group.     

In vitro production of porcine embryos: current status,future perspectives and alternative applications

The pig is considered to be a suitable source of cells and organs for xenotransplants, as well as a transgenic animal to produce specific proteins, given the biological similarities it shares with human beings. However, the in vitro embryo production system in pigs is inefficient compared with those in other mammals, such as cattle or mice. Although numerous modifications have been applied to improve the efficiency of in vitro embryo production systems in pigs, not much progress has been made to overcome the problem of polyspermy, and low developmental ability due to insufficient cytoplasmic abilities of in vitro matured oocytes and improper culture conditions for the in vitro produced embryos. Recent achievements, such as the establishment of chemically defined medium and utilization of ‘zona hardening’ technique, have gained some success. However, further research for the reduction of polyspermy and detrimental effects of the culture systems in pigs is still needed.     

Leishmaniasis: current situation and new perspectives

Leishmaniasis represents a complex of diseases with an important clinical and epidemiological diversity. Visceral leishmaniasis (VL) is of higher priority than cutaneous leishmaniasis (CL) as it is a fatal disease in the absence of treatment. Anthroponotic VL foci are of special concern as they are at the origin of frequent and deathly epidemics (e.g. Sudan). Leishmaniasis burden remains important: 88 countries, 350 million people at risk, 500,000 new cases of VL per year, 1-1.5 million for CL and DALYs: 2.4 millions. Most of the burden is concentrated on few countries which allows clear geographic priorities. Leishmaniasis is still an important public health problem due to not only environmental risk factors such as massive migrations, urbanisation, deforestation, new irrigation schemes, but also to individual risk factors: HIV, malnutrition, genetic, etc em leader Leishmaniasis is part of those diseases which still requires improved control tools. Consequently WHO/TDR research for leishmaniasis has been more and more focusing on the development of new tools such as diagnostic tests, drugs and vaccines. The ongoing effort has already produced significant results. The newly available control tools should allow a scaling up of control activities in priority areas. In anthroponotic foci, the feasibility of getting a strong impact on mortality, morbidity and transmission, is high.     

Vaccination of cattle against bovine schistosomosis: current status and future prospects: a review

Bovine schistosomosis, caused by Schistosoma bovis, constitutes a serious veterinary problem in many parts of the world. The vaccination approaches for the control of bovine schistosomosis include the use of irradiation-attenuated S. bovis cercarial or schistosomular vaccines, S. bovis adult worms or whole-egg antigens and defined antigen vaccine. Irradiated S. bovis cercarial or schistosomular vaccines provide partial protection against S. bovis infection. However, this type of vaccine requires live infectious cercariae or viable schistosomula for induction of protection. Unfortunately, experimental immunizations with dead schistosome antigens have been largely unsuccessful. The surge of new techniques in cellular immunology and molecular biology has made possible the development of potential candidate vaccine antigens from various species of schistosomes including S. bovis. The efficiency of these vaccines has been evaluated in experimentally infected calves. These vaccines will probably replace the irradiated S. bovis vaccines. A broad-spectrum antischistosome vaccine which can kill a variety of human and animal schistosome species is yet to be produced.     

DNA vaccination against influenza viruses: a review with emphasis on equine and swine influenza

The influenza virus vaccines that are commercially-available for humans, horses and pigs in the United States are inactivated, whole-virus or subunit vaccines. While these vaccines may decrease the incidence and severity of clinical disease, they do not consistently provide complete protection from virus infection. DNA vaccines are a novel alternative to conventional vaccination strategies, and offer many of the potential benefits of live virus vaccines without their risks. In particular, because immunogens are synthesized de novo within DNA transfected cells, antigen can be presented by MHC class I and II molecules, resulting in stimulation of both humoral and cellular immune responses. Influenza virus has been used extensively as a model pathogen in DNA vaccine studies in mice, chickens, ferrets, pigs, horses and non-human primates, and clinical trials of DNA-based influenza virus vaccines are underway in humans. Our studies have focused on gene gun delivery of DNA vaccines against equine and swine influenza viruses in mice, ponies and pigs, including studies employing co-administration of interleukin-6 DNA as an approach for modulating and adjuvanting influenza virus hemagglutinin-specific immune responses. The results indicate that gene gun administration of plasmids encoding hemagglutinin genes from influenza viruses is an effective method for priming and/or inducing virus-specific immune responses, and for providing partial to complete protection from challenge infection in mice, horses and pigs. In addition, studies of interleukin-6 DNA co-administration in mice clearly demonstrate the potential for this approach to enhance vaccine efficacy and protection.     

Zataria Multiflora bois as an auspicious therapeutic approach against Echinococcus granulosus: Current status and future perspectives

Hydatidosis caused by Echinococcus granulosus is a major zoonotic diseases. In addition to imposing heavy economic losses, the disease is a public health problem worldwide. The larval stage of the parasite (hydatid cyst) is formed in a wide range of domestic, wild and human beings as intermediate hosts. On the other, its recurrence has been reported anywhere as a reemerging disease. Although the cysts have some evading mechanisms, both human TH1 and TH2 cells subsets are stimulated. Because of increasing resistance and adverse effects of medications such as abnormalities of liver and other organs functions and abdominal pain, seeking alternative therapeutic approaches to be inexpensive, easy available, with low side effects and toxicity seems essential. However, the lack of information on the social and economic welfares of herbal medicines for the industrial scale application is a limitation. Zataria Multiflora bois (ZMB) has exhibited huge advantages and tremendous protoscolicidal effects as demonstrated by numerous studies and its combination therapies with anti-parasitic drugs have exerted desirable outcomes in vitro and in vivo. Noticeably, the compound confers negligible side effects or toxicity even at high concentrations. ZMB has exhibited promising inhibitory effects against hydatid cyst, particularly when combined with chemical drugs and in formulations of nanoemulsions. Its immunomodulatory effects include increase of nitric oxide production (NO) and protection of hepatic cells (Kupffer cells, fat-storing cells, and endothelial cells), enhancement of macrophages and T cells and increase of cytokines production. This study aimed at assessment of ZMB traits for application against hydatid cyst protoscolices.     

Effects of DNA dose,route of vaccination,and coadministration of porcine interleukin-6 DNA on results of DNA vaccination against influenza virus infection in pigs

OBJECTIVE: To examine the effects of DNA dose, site of vaccination, and coadministration of a cytokine DNA adjuvant on efficacy of H1-subtype swine influenza virus hemagglutinin (HA) DNA vaccination of pigs. ANIMALS: 24 eight-week-old mixed-breed pigs. PROCEDURE: 2 doses of DNA were administered 27 days apart by use of a particle-mediated delivery system (gene gun). Different doses of HA DNA and different sites of DNA administration (skin, tongue) were studied, as was coadministration of porcine interleukin-6 (pIL-6) DNA as an adjuvant. Concentrations of virus-specific serum and nasal mucosal antibodies were measured throughout the experiment, and protective immunity was assessed after intranasal challenge with homologous H1N1 swine influenza virus. RESULTS: Increasing the dose of HA DNA, but not coadministration of pIL6 DNA, significantly enhanced virus-specific serum antibody responses. Pigs that received DNA on the ventral surface of the tongue stopped shedding virus 1 day sooner than pigs vaccinated in the skin of the ventral portion of the abdomen, but none of the vaccinated pigs developed detectable virus-specific antibodies in nasal secretions prior to challenge, nor were they protected from challenge exposure. Vaccinated pigs developed high virus-specific antibody concentrations after exposure to the challenge virus. CONCLUSIONS AND CLINICAL RELEVANCE: Co-administration of pIL-6 DNA did not significantly enhance immune responses to HA DNA vaccination or protection from challenge exposure. However, HA DNA vaccination of pigs, with or without coadministration of pIL-6 DNA, induced strong priming of the humoral immune system.     

Immunomodulatory effect of swine CCL20 chemokine in DNA vaccination against CSFV

The objective of this work was to explore whether a plasmid expressing CCL20 chemokine could improve the immune response against CSFV in co-administration with a DNA vaccine expressing the E2 protein. The immunization of pigs with the DNA vaccine formulation, that contains swine CCL20 chemokine, resulted in the homogenous induction of detectable levels of CSFV antibodies at 36 days after the first injection. Remarkably, immunized animals with E2 DNA vaccine in co-administration with the plasmid containing swine CCL20 developed high titers of neutralizing antibodies against homologous and heterologous CSFV strains and were totally protected upon a lethal viral challenge (sterilizing protection). Our results confirm the role of CCL20 to increase antibody-mediated responses. At the same time suggest the ability of CCL20 to enhance the T helper cell response associated with the induction of neutralizing antibodies against CSFV in pigs previously reported. Systemic replication of virulent CSFV in vivo during the acute phase of infection induces type I IFN. Lower average values of IFN alpha were detected in the serum of pigs immunized with pE2 and pCCL20 at 3 days after challenge. The levels of IFN-alpha detected in pigs immunized with pE2 and principally in non-vaccinated challenged animals can be related to viral load in serum at 3 and 7 days post infection and the clinical signs observed. Our results emphasized the capacity of swine CCL20 chemokine to enhance cellular, humoral and anti viral response with an adjuvant effect in the immune response elicited by E2-DNA vaccination against CSFV. To our knowledge, this is the first report demonstrating the adjuvant effect of swine CCL20 to effectively enhance the potential of DNA vaccine in the immune induction and protection against virus challenge in swine infection model.     

c-DNA vaccination against parasitic infections: advantages and disadvantages

Recently developed technology for DNA vaccination appears to offer the good prospect for the development of a multivalent vaccines that will effectively activate both the humoral and cell mediated mechanisms of the immune system. Currently, DNA vaccination against such important parasitic diseases like malaria, leishmaniosis, toxoplasmosis, cryptosporidiosis, schistosomosis, fasciolosis offers several new opportunities. However, the outcome of vaccination depends very much on vaccine formulations, dose and route of vaccine delivery, and the species and even strain of the vaccinated host. To overcome these problems much research is still needed, specifically focused on cloning and testing of new c-DNA sequences in the following: genome projects: different ways of delivery: design of vectors containing appropriate immunostimulatory sequences and very detailed studies on safety.     

Brucellosis in Mexico: current status and trends

Traditionally, Mexico has been recognized as endemic with brucellosis. The improvements in diagnostics techniques and vaccination strategies and the enforcement of a national eradication policy have contributed significantly to making progress in the control of brucellosis. The current status of brucellosis and its risk factors, in the different production species as well as in human population is reviewed. Also the trends in control and eventual eradication strategies and perspectives for the near future of Mexico are presented.     

禽核酸疫苗的研究进展

本文对禽用（鸡、鸭、火鸡）核酸疫苗的研究进行综述。首先描述禽用核酸疫苗的进展：病原,质粒以及免疫途径。其次,描述提高核酸疫苗免疫效果的方式：接种途径,疫苗剂量以及首免时间,增加宿主细胞对质粒的摄入,添加免疫增强分子,优化质粒骨架和密码子,疫苗抗原的选择,异源性的首免-加强免疫策略。最后,描述禽用核酸疫苗的其他特点：接种后质粒的去向,免疫反应的特点以及核酸疫苗的其他用途。