-
Trends in Parasitology Mar 2017Eimeria pose a risk to all livestock species as a cause of coccidiosis, reducing productivity and compromising animal welfare. Pressure to reduce drug use in the food... (Review)
Review
Eimeria pose a risk to all livestock species as a cause of coccidiosis, reducing productivity and compromising animal welfare. Pressure to reduce drug use in the food chain makes the development of cost-effective vaccines against Eimeria essential. For novel vaccines to be successful, understanding genetic and antigenic diversity in field populations is key. Eimeria species that infect chickens are most significant, with Eimeria tenella among the best studied and most economically important. Genome-wide single nucleotide polymorphism (SNP)-based haplotyping has been used to determine population structure, genotype distribution, and potential for cross-fertilization between E. tenella strains. Here, we discuss recent developments in our understanding of diversity for Eimeria in relation to its specialized life cycle, distribution across the globe, and the challenges posed to vaccine development.
Topics: Animals; Eimeria; Genetic Variation; Genotype; Polymorphism, Single Nucleotide; Protozoan Vaccines
PubMed: 27593338
DOI: 10.1016/j.pt.2016.08.007 -
Advanced Healthcare Materials Jul 2018Nanomedicine approaches have the potential to transform the battle against parasitic worm (helminth) infections, a major global health scourge from which billions are... (Review)
Review
Nanomedicine approaches have the potential to transform the battle against parasitic worm (helminth) infections, a major global health scourge from which billions are currently suffering. It is anticipated that the intersection of two currently disparate fields, nanomedicine and helminth biology, will constitute a new frontier in science and technology. This progress report surveys current innovations in these research fields and discusses research opportunities. In particular, the focus is on: (1) major challenges that helminth infections impose on mankind; (2) key aspects of helminth biology that inform future research directions; (3) efforts to construct nanodelivery platforms to target drugs and genes to helminths hidden in their hosts; (4) attempts in applying nanotechnology to enable vaccination against helminth infections; (5) outlooks in utilizing nanoparticles to enhance immunomodulatory activities of worm-derived factors to cure allergy and autoimmune diseases. In each section, achievements are summarized, limitations are explored, and future directions are assessed.
Topics: Animals; Drug Delivery Systems; Drug Resistance; Gene Transfer Techniques; Helminthiasis; Helminths; Host-Parasite Interactions; Humans; Immunotherapy; Nanomedicine; Nanoparticles; Protozoan Vaccines
PubMed: 29602254
DOI: 10.1002/adhm.201701494 -
Irish Journal of Medical Science Feb 2023Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis. It has been shown that the severity of symptoms depends on the functioning of the host... (Review)
Review
Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis. It has been shown that the severity of symptoms depends on the functioning of the host immune system. Although T. gondii infection typically does not lead to severe disease in healthy people and after infection, it induces a stable immunity, but it can contribute to severe and even lethal Toxoplasmosis in immunocompromised individuals (AIDS, bone marrow transplant and neoplasia). The antigens that have been proposed to be used in vaccine candidate in various studies include surface antigens and secretory excretions that have been synthesized and evaluated in different studies. In some studies, secretory antigens play an important role in stimulating the host immune response. Various antigens such as SAG, GRA, ROP, ROM, and MAG have been from different strains of T. gondii have been synthesized and their protective effects have been evaluated in animal models in different vaccine platforms including recombinant antigens, nanoparticles, and DNA vaccine. Four bibliographic databases including Science Direct, PubMed Central (PMC), Scopus, and Google Scholar were searched for articles published up to 2020.The current review article focuses on recent studies on the use and usefulness of recombinant antigens, nanoparticles, and DNA vaccines.
Topics: Animals; Humans; Mice; Toxoplasma; Antigens, Protozoan; Protozoan Proteins; Protozoan Vaccines; Toxoplasmosis; Vaccines, DNA; Mice, Inbred BALB C
PubMed: 35394635
DOI: 10.1007/s11845-022-02998-9 -
Trends in Parasitology Sep 2021African trypanosomes cause diseases of humans and their livestock. To date, a much-desired vaccine has been elusive, due in part to the immune evasion mechanisms of... (Review)
Review
African trypanosomes cause diseases of humans and their livestock. To date, a much-desired vaccine has been elusive, due in part to the immune evasion mechanisms of these cunning parasites. However, Autheman et al. have used a bold, high-throughput screen to provide hope that vaccines may be on the way.
Topics: Animals; Host-Parasite Interactions; Humans; Immune Evasion; Protozoan Vaccines; Trypanosoma; Trypanosomiasis, African
PubMed: 34315657
DOI: 10.1016/j.pt.2021.07.005 -
Expert Review of Vaccines 2024
Topics: Humans; Malaria Vaccines; Malaria, Falciparum; Plasmodium falciparum; Antibodies, Protozoan; Protozoan Proteins
PubMed: 38095048
DOI: 10.1080/14760584.2023.2292204 -
Parasitology Sep 2014Coccidiosis, a serious disease resulting from infection with parasitic protozoa of the genus Eimeria, causes significant economic losses to the poultry industry, where... (Review)
Review
Coccidiosis, a serious disease resulting from infection with parasitic protozoa of the genus Eimeria, causes significant economic losses to the poultry industry, where intensive rearing facilitates transmission of infectious oocysts via the fecal/oral route. Current control relies primarily on prophylactic drugs in feed but, whilst cost effective, the rise of drug resistance and public demands for residue-free meat has encouraged development of alternative control strategies. Chickens that recover from infection with Eimeria develop solid immunity that is directed against the early asexual stages of the parasite life cycle. This has allowed development of a number of vaccines that utilize deliberate infection with controlled doses of virulent oocysts or reproductively attenuated lines of Eimeria. The latter are immunogenic but non-pathogenic. The realization that both prophylactic drugs and attenuated vaccines control but do not eradicate infection with Eimeria encouraged development of a vaccine based upon maternal immunity. Laying hens exposed to Eimeria are able to transfer protective antibodies to hatchlings via egg yolks and these antibodies have been used to identify parasite proteins that are conserved across the genus. When delivered maternally, these provide an economical means of preventing coccidiosis, offering immediate protection to newly hatched chicks.
Topics: Animals; Antibodies, Protozoan; Antigens, Protozoan; Chickens; Coccidiosis; Drug Resistance, Multiple; Eimeria; Female; Humans; Immunity, Maternally-Acquired; Life Cycle Stages; Oocysts; Poultry Diseases; Pre-Exposure Prophylaxis; Protozoan Vaccines; Vaccines, Attenuated
PubMed: 24534138
DOI: 10.1017/S0031182014000195 -
Frontiers in Immunology 2020Congenital toxoplasmosis has a high impact on human disease worldwide, inducing serious consequences from fetus to adulthood. Despite this, there are currently no human... (Review)
Review
Congenital toxoplasmosis has a high impact on human disease worldwide, inducing serious consequences from fetus to adulthood. Despite this, there are currently no human vaccines available to prevent this infection. Most vaccination studies against infection used animal models in which the infection was established by exogenous inoculation. Here, we review recent research on potential vaccines using animal models in which infection was congenitally established. Endeavors in this field have so far revealed that live or subunit vaccines previously found to confer protection against extrinsically established infections can also protect, at least partially, from vertically transmitted infection. Nevertheless, there is no consensus on the more adequate immune response to protect the host and the fetus in congenital infection. Most of the vaccination studies rely on the assessment of maternal systemic immune responses, quantification of parasitic loads in the fetuses, and survival indexes and/or brain parasitic burden in the neonates. More research must be carried out not only to explore new vaccines but also to further study the nature of the elicited immune protection at the maternal-fetal interface. Particularly, the cellular and molecular effector mechanisms at the maternal-fetal interface induced by immunization remain poorly characterized. Deeper knowledge on the immune response at this specific location will certainly help to refine the vaccine-induced immunity and, consequently, to provide the most effective and safest protection against vertical infection.
Topics: Animals; Antibodies, Protozoan; Humans; Infectious Disease Transmission, Vertical; Protozoan Proteins; Protozoan Vaccines; Toxoplasma; Toxoplasmosis, Congenital
PubMed: 33658997
DOI: 10.3389/fimmu.2020.621997 -
Biomedicine & Pharmacotherapy =... May 2021Human filarial infections are vector-borne nematode infections, which include lymphatic filariasis, onchocerciasis, loiasis, and mansonella filariasis. With a high... (Review)
Review
Human filarial infections are vector-borne nematode infections, which include lymphatic filariasis, onchocerciasis, loiasis, and mansonella filariasis. With a high prevalence in developing countries, filarial infections are responsible for some of the most debilitating morbidities and a vicious cycle of poverty and disease. Global initiatives set to eradicate these infections include community mass treatments, vector control, provision of care for morbidity, and search for vaccines. However, there are growing challenges associated with mass treatments, vector control, and antifilarial vaccine development. With the emergence of genome editing tools and successful applications in other infectious diseases, the integration of genetic editing techniques in future control strategies for filarial infections would offer the best option for eliminating filarial infections. In this review, we briefly discuss the mechanisms of the three main genetic editing techniques and explore the potential applications of these powerful tools to control filarial infections.
Topics: Animals; CRISPR-Associated Protein 9; CRISPR-Cas Systems; Clustered Regularly Interspaced Short Palindromic Repeats; Filariasis; Filaricides; Filarioidea; Gene Editing; Genetic Therapy; Humans; Protozoan Vaccines
PubMed: 33581654
DOI: 10.1016/j.biopha.2021.111292 -
Parasites & Vectors Feb 2015Chagas disease is a zoonosis caused by Trypanosoma cruzi in which the most affected organ is the heart. Conventional chemotherapy has a very low effectiveness; despite... (Review)
Review
Chagas disease is a zoonosis caused by Trypanosoma cruzi in which the most affected organ is the heart. Conventional chemotherapy has a very low effectiveness; despite recent efforts, there is currently no better or more effective treatment available. DNA vaccines provide a new alternative for both prevention and treatment of a variety of infectious disorders, including Chagas disease. Recombinant DNA technology has allowed some vaccines to be developed using recombinant proteins or virus-like particles capable of inducing both a humoral and cellular specific immune response. This type of immunization has been successfully used in preclinical studies and there are diverse models for viral, bacterial and/or parasitic diseases, allergies, tumors and other diseases. Therefore, several research groups have been given the task of designing a DNA vaccine against experimental infection with T. cruzi. In this review we explain what DNA vaccines are and the most recent studies that have been done to develop them with prophylactic or therapeutic purposes against Chagas disease.
Topics: Animals; Chagas Disease; Drug Discovery; Humans; Protozoan Vaccines; Vaccination; Vaccines, DNA
PubMed: 25885641
DOI: 10.1186/s13071-015-0738-0 -
Critical Reviews in Immunology 2017The reports in 1993 that naked DNA encoding viral genes conferred protective immunity came as a surprise to most vaccinologists. This review analyses the expanding... (Review)
Review
The reports in 1993 that naked DNA encoding viral genes conferred protective immunity came as a surprise to most vaccinologists. This review analyses the expanding number of examples where plasmid DNA induces immune responses. Issues such as the type of immunity induced, mechanisms of immune protection, and how DNA vaccines compare with other approaches are emphasized. Additional issues discussed include the likely means by which DNA vaccines induce CTL, how the potency and type of immunity induced can be modified, and whether DNA vaccines represent a practical means of manipulating unwanted immune response occurring during immunoinflammatory diseases. It seems doubtful if DNA vaccines will replace currently effective vaccines, but they may prove useful for prophylactic use against some agents that at present lack an effective vaccine. DNA vaccines promise to be valuable to manipulate the immune response in situations where responses to agents are inappropriate or ineffective.
Topics: Animals; Antigens, Bacterial; Antigens, Protozoan; Antigens, Viral; Bacterial Vaccines; Genetic Vectors; History, 20th Century; History, 21st Century; Humans; Immunogenicity, Vaccine; Plasmids; Protozoan Vaccines; Vaccination; Vaccines, DNA; Vaccinology; Viral Vaccines
PubMed: 29773031
DOI: 10.1615/CritRevImmunol.v37.i2-6.140