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PLoS Pathogens Sep 2018
Review
Topics: Animals; Diarrhea; Giardia lamblia; Giardiasis; Humans; Protozoan Vaccines; Vacuoles
PubMed: 30261050
DOI: 10.1371/journal.ppat.1007250 -
Canadian Journal of Gastroenterology &... 2018is the responsible parasite of amoebiasis and remains one of the top three parasitic causes of mortality worldwide. With increased travel and emigration to developed... (Review)
Review
is the responsible parasite of amoebiasis and remains one of the top three parasitic causes of mortality worldwide. With increased travel and emigration to developed countries, infection is becoming more common in nonendemic areas. Although the majority of individuals infected with remain asymptomatic, some present with amoebic colitis and disseminated disease. As more is learned about its pathogenesis and the host's immune response, the potential for developing a vaccine holds promise. This narrative review outlines the current knowledge regarding and and insight in the development of a vaccine.
Topics: Antiprotozoal Agents; Dysentery, Amebic; Entamoeba histolytica; Entamoebiasis; Humans; Protozoan Vaccines; Travel
PubMed: 30631758
DOI: 10.1155/2018/4601420 -
The Lancet. Infectious Diseases Jan 2015Cryptosporidium spp are well recognised as causes of diarrhoeal disease during waterborne epidemics and in immunocompromised hosts. Studies have also drawn attention to... (Review)
Review
Cryptosporidium spp are well recognised as causes of diarrhoeal disease during waterborne epidemics and in immunocompromised hosts. Studies have also drawn attention to an underestimated global burden and suggest major gaps in optimum diagnosis, treatment, and immunisation. Cryptosporidiosis is increasingly identified as an important cause of morbidity and mortality worldwide. Studies in low-resource settings and high-income countries have confirmed the importance of cryptosporidium as a cause of diarrhoea and childhood malnutrition. Diagnostic tests for cryptosporidium infection are suboptimum, necessitating specialised tests that are often insensitive. Antigen-detection and PCR improve sensitivity, and multiplexed antigen detection and molecular assays are underused. Therapy has some effect in healthy hosts and no proven efficacy in patients with AIDS. Use of cryptosporidium genomes has helped to identify promising therapeutic targets, and drugs are in development, but methods to assess the efficacy in vitro and in animals are not well standardised. Partial immunity after exposure suggests the potential for successful vaccines, and several are in development; however, surrogates of protection are not well defined. Improved methods for propagation and genetic manipulation of the organism would be significant advances.
Topics: Antiprotozoal Agents; Cryptosporidiosis; Diagnostic Tests, Routine; Diarrhea; Global Health; Humans; Protozoan Vaccines
PubMed: 25278220
DOI: 10.1016/S1473-3099(14)70772-8 -
Frontiers in Cellular and Infection... 2017Vaccination is an efficient means of combating infectious disease burden globally. However, routine vaccines for the world's major human parasitic diseases do not yet... (Review)
Review
Vaccination is an efficient means of combating infectious disease burden globally. However, routine vaccines for the world's major human parasitic diseases do not yet exist. Vaccines based on carbohydrate antigens are a viable option for parasite vaccine development, given the proven success of carbohydrate vaccines to combat bacterial infections. We will review the key components of carbohydrate vaccines that have remained largely consistent since their inception, and the success of bacterial carbohydrate vaccines. We will then explore the latest developments for both traditional and non-traditional carbohydrate vaccine approaches for three of the world's major protozoan parasitic diseases-malaria, toxoplasmosis, and leishmaniasis. The traditional prophylactic carbohydrate vaccine strategy is being explored for malaria. However, given that parasite disease biology is complex and often arises from host immune responses to parasite antigens, carbohydrate vaccines against deleterious immune responses in host-parasite interactions are also being explored. In particular, the highly abundant glycosylphosphatidylinositol molecules specific for , and spp. are considered exploitable antigens for this non-traditional vaccine approach. Discussion will revolve around the application of these protozoan carbohydrate antigens for vaccines currently in preclinical development.
Topics: Adjuvants, Immunologic; Animals; Antigens, Protozoan; Bacterial Vaccines; Carbohydrates; Glycosylphosphatidylinositols; Host-Parasite Interactions; Humans; Leishmania; Leishmaniasis; Malaria; Malaria Vaccines; Parasites; Parasitic Diseases; Plasmodium; Protozoan Vaccines; Toxoplasma; Toxoplasmosis; Vaccination
PubMed: 28660174
DOI: 10.3389/fcimb.2017.00248 -
Journal of Immunological Methods Sep 2017Monoclonal antibody technologies have enabled dramatic advances in immunology, the study of infectious disease, and modern medicine over the past 40years. However, many...
Monoclonal antibody technologies have enabled dramatic advances in immunology, the study of infectious disease, and modern medicine over the past 40years. However, many monoclonal antibody discovery procedures are labor- and time-intensive, low efficiency, and expensive. Here we describe an optimized mAb discovery platform for the rapid and efficient isolation, cloning and characterization of monoclonal antibodies in murine systems. In this platform, antigen-binding splenic B cells from immunized mice are isolated by FACS and cocultured with CD40L positive cells to induce proliferation and mAb production. After 12days of coculture, cell culture supernatants are screened for antigen, and IgG positivity and RNA is isolated for reverse-transcription. Positive-well cDNA is then amplified by PCR and the resulting amplicons can be cloned into ligation-independent expression vectors, which are then used directly to transfect HEK293 cells for recombinant antibody production. After 4days of growth, conditioned medium can be screened using biolayer interferometry for antigen binding and affinity measurements. Using this method, we were able to isolate six unique, functional monoclonal antibodies against an antigen of the human malaria parasite Plasmodium falciparum. Importantly, this method incorporates several important advances that circumvent the need for single-cell PCR, restriction cloning, and large scale protein production, and can be applied to a wide array of protein antigens.
Topics: 5' Untranslated Regions; Animals; Antibodies, Monoclonal; Antibody Formation; Antibody Specificity; Antigens; B-Lymphocytes; CD40 Ligand; Cell Proliferation; Cell Separation; Clone Cells; Cloning, Molecular; Coculture Techniques; Flow Cytometry; HEK293 Cells; Humans; Immunization; Lymphocyte Activation; Malaria Vaccines; Mice, Inbred BALB C; Plasmodium falciparum; Polymerase Chain Reaction; Protozoan Proteins; Workflow
PubMed: 28554543
DOI: 10.1016/j.jim.2017.05.010 -
F1000Research 2020Much of the gain in malaria control, in terms of regional achievements in restricting geographical spread and reducing malaria cases and deaths, can be attributed to... (Review)
Review
Much of the gain in malaria control, in terms of regional achievements in restricting geographical spread and reducing malaria cases and deaths, can be attributed to large-scale deployment of antimalarial drugs, insecticide-treated bed nets, and early diagnostics. However, despite impressive progress, control efforts have stalled because of logistics, unsustainable delivery, or short-term effectiveness of existing interventions or a combination of these reasons. A highly efficacious malaria vaccine as an additional tool would go a long way, but success in the development of this important intervention remains elusive. Moreover, most of the vaccine candidate antigens that were investigated in early-stage clinical trials, selected partly because of their immunogenicity and abundance during natural malaria infection, were polymorphic or structurally complex or both. Likewise, we have a limited understanding of immune mechanisms that confer protection. We reflect on some considerable technological and scientific progress that has been achieved and the lessons learned.
Topics: Antigens, Protozoan; Humans; Malaria; Malaria Vaccines
PubMed: 32399189
DOI: 10.12688/f1000research.22143.1 -
Frontiers in Immunology 2021
Topics: Animals; Female; Host-Parasite Interactions; Humans; Parasites; Pregnancy; Pregnancy Complications, Parasitic; Protozoan Vaccines
PubMed: 34975925
DOI: 10.3389/fimmu.2021.813446 -
Frontiers in Immunology 2018Extracellular vesicles (EVs) are small membrane-surrounded structures released by different kinds of cells (normal, diseased, and transformed cells) and that contain... (Review)
Review
Extracellular vesicles (EVs) are small membrane-surrounded structures released by different kinds of cells (normal, diseased, and transformed cells) and that contain large amounts of important substances (such as lipids, proteins, metabolites, DNA, RNA, and non-coding RNA (ncRNA), including miRNA, lncRNA, tRNA, rRNA, snoRNA, and scaRNA) in an evolutionarily conserved manner. EVs, including exosomes, play a role in the transmission of information, and substances between cells that is increasingly being recognized as important. In some infectious diseases such as parasitic diseases, EVs have emerged as a ubiquitous mechanism for mediating communication during host-parasite interactions. EVs can enable multiple modes to transfer virulence factors and effector molecules from parasites to hosts, thereby regulating host gene expression, and immune responses and, consequently, mediating the pathogenic process, which has made us rethink our understanding of the host-parasite interface. Thus, here, we review the present findings regarding EVs (especially exosomes) and recognize the role of EVs in host-parasite interactions. We hope that a better understanding of the mechanisms of parasite-derived EVs may provide new insights for further diagnostic biomarker, vaccine, and therapeutic development.
Topics: Animals; Antiprotozoal Agents; Biomarkers; Exosomes; Host-Parasite Interactions; Humans; Parasites; Parasitic Diseases; Protozoan Vaccines; Virulence Factors
PubMed: 30697211
DOI: 10.3389/fimmu.2018.03066 -
Parasitology International Oct 2021An estimated 229 million cases of malaria occurred worldwide in 2019. Both, Plasmodium falciparum and P. vivax are responsible for most of the malaria disease burden in... (Review)
Review
An estimated 229 million cases of malaria occurred worldwide in 2019. Both, Plasmodium falciparum and P. vivax are responsible for most of the malaria disease burden in the world. Despite difficulties in obtaining an accurate number, the global estimates of cases in 2019 are approximately 229 million of which 2.8% are due to P. vivax, and the total number of malaria deaths are approximately 409 million. Regional elimination or global eradication of malaria will be a difficult task, particularly for P. vivax due to the particular biological features related to the hypnozoite, leading to relapse. Countries that have shown successful episodes of a decrease in P. falciparum malaria, are left with remaining P. vivax malaria cases. This is caused by the mechanism that the parasite has evolved to remain dormant in the liver forming hypnozoites. Furthermore, while clinical trials of vaccines against P. falciparum are making fast progress, a very different picture is seen with P. vivax, where only few candidates are currently active in clinical trials. We discuss the challenge that represent the hypnozoite for P. vivax vaccine development, the potential of Controlled Human Malaria Challenges (CHMI) and the leading vaccine candidates assessed in clinical trials.
Topics: Animals; Humans; Malaria Vaccines; Malaria, Vivax; Plasmodium vivax
PubMed: 34166786
DOI: 10.1016/j.parint.2021.102411 -
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