Novel Competitive ELISA Utilizing Trimeric Spike Protein of SARS-CoV-2, Could Identify More Than RBD-RBM Specific Neutralizing Antibodies in Hybrid Sera.

Since the initiation of the COVID-19 pandemic, there has been a need for the development of diagnostic methods to determine the factors implicated in mounting an immune response against the virus. The most promising indicator has been suggested to be neutralizing antibodies (nAbs), which mainly block the interaction between the Spike protein (S) of SARS-CoV-2 and the host entry receptor ACE2. In this study, we aimed to develop and optimize conditions of a competitive ELISA to measure serum neutralizing titer, using a recombinant trimeric Spike protein modified to have six additional proline residues (S(6P)-HexaPro) and h-ACE2.

Dietary Supplementation Effects on Growth, Oxidative Status, and Immunity of Gilthead Seabream ( L.).

Fish infectious diseases are one of the main constraints of the aquaculture sector. The use of medicinal plants provides a sustainable way of protection using safe, eco-friendly compounds in a more cost-effective way of treatment, compared to antibiotics. The aim of the present study is the assessment of (AA) feed-supplementation effects on gilthead seabream ().

Nervous Necrosis Virus Modulation of European Sea Bass (, L.) Immune Genes and Transcriptome towards Establishment of Virus Carrier State.

Viral infections of teleost fish have great environmental and economic implications in aquaculture. Nervous necrosis virus (NNV) is a pathogen affecting more than 120 different species, causing high mortality and morbidity. Herein, we studied the course of NNV experimental infection of , focusing on survivors which indicated viral carrier state.

Development of a novel squalene/α-tocopherol-based self-emulsified nanoemulsion incorporating Leishmania peptides for induction of antigen-specific immune responses.

Vaccination has emerged as the most effective strategy to confront infectious diseases, among which is leishmaniasis, that threat public health. Despite laborious efforts there is still no vaccine for humans to confront leishmaniasis. Multi-epitope protein/peptide vaccines present a number of advantages, however their use along with appropriate adjuvants that may also act as antigen carriers is considered essential to overcome subunit vaccines' low immunogenicity.

Intramuscular Immunization with a Liposomal Multi-Epitope Chimeric Protein Induces Strong Cellular Immune Responses against Visceral Leishmaniasis.

Control of the intracellular parasite (.) requires the activation of strong type 1 cellular immune responses. Towards this goal, in the present study, a multiepitope chimeric protein named LiChimera was encapsulated into cationic liposomes and its protective efficacy against experimental visceral leishmaniasis was investigated.

A liposomal vaccine promotes strong adaptive immune responses via dendritic cell activation in draining lymph nodes.

Subunit proteins provide a safe source of antigens for vaccine development especially for intracellular infections which require the induction of strong cellular immune responses. However, those antigens are often limited by their low immunogenicity. In order to achieve effective immune responses, they should be encapsulated into a stable antigen delivery system combined with an appropriate adjuvant.

Immunoinformatics Approach to Design a Multi-Epitope Nanovaccine against Parasite: Elicitation of Cellular Immune Responses.

Leishmaniasis is a vector-borne disease caused by an intracellular parasite of the genus with different clinical manifestations that affect millions of people worldwide, while the visceral form may be fatal if left untreated. Since the available chemotherapeutic agents are not satisfactory, vaccination emerges as the most promising strategy for confronting leishmaniasis. In the present study, a reverse vaccinology approach was adopted to design a pipeline starting from proteome analysis of three different species and ending with the selection of a pool of MHCI- and MHCII-binding epitopes.

Antibody and T-Cell Subsets Analysis Unveils an Immune Profile Heterogeneity Mediating Long-term Responses in Individuals Vaccinated Against SARS-CoV-2.

Background: Based on the fact that coronavirus disease 2019 (COVID-19) is still spreading despite worldwide vaccine administration, there is an imperative need to understand the underlying mechanisms of vaccine-induced interindividual immune response variations.

Methods: We compared humoral and cellular immune responses in 127 individuals vaccinated with either BNT162b2, mRNA-1273, or ChAdOx1-nCoV-19 vaccine.

Results: Both mRNA vaccines induced faster and stronger humoral responses as assessed by high spike- and RBD-specific antibody titers and neutralizing efficacy in comparison to ChAdOx1-nCoV-19 vaccine.

Transcriptional Profiling of Infected Dendritic Cells: Insights into the Role of Immunometabolism in Host-Parasite Interaction.

parasites are capable of effectively invading dendritic cells (DCs), a cell population orchestrating immune responses against several diseases, including leishmaniasis, by bridging innate and adaptive immunity. on the other hand has evolved various mechanisms to subvert DCs activation and establish infection. Thus, the transcriptional profile of DCs derived from bone marrow (BMDCs) that have been infected with parasite or of DCs exposed to chemically inactivated parasites was investigated via RNA sequencing, aiming to better understand the host-pathogen interplay.

Transcriptomic Analysis of Fish Hosts Responses to Nervous Necrosis Virus.

Nervous necrosis virus (NNV) has been responsible for mass mortalities in the aquaculture industry worldwide, with great economic and environmental impact. The present review aims to summarize the current knowledge of gene expression responses to nervous necrosis virus infection in different fish species based on transcriptomic analysis data. Four electronic databases, including PubMed, Web of Science, and SCOPUS were searched, and more than 500 publications on the subject were identified.

Paper Lateral Flow Biosensor for Nodavirus Reverse Transcribed RNA Detection.

Paper nanobiosensors have been established as an excellent platform for analysis of veterinary and human pathogens causing various diseases. Especially, lateral flow assays or biosensors ideal for sensitive, rapid, robust and accurate analysis in laboratory setups and on-site analysis. Viral RNA detection is of great importance for public health as well as animal health protection.

A Canine-Directed Chimeric Multi-Epitope Vaccine Induced Protective Immune Responses in BALB/c Mice Infected with .

Leishmaniases are complex vector-borne diseases caused by intracellular parasites of the genus . The visceral form of the disease affects both humans and canids in tropical, subtropical, and Mediterranean regions. One health approach has suggested that controlling zoonotic visceral leishmaniasis (ZVL) could have an impact on the reduction of the human incidence of visceral leishmaniasis (VL).

Development of a Nanoparticle-based Lateral Flow Strip Biosensor for Visual Detection of Whole Nervous Necrosis Virus Particles.

Effective analysis of pathogens causing human and veterinary diseases demands rapid, specific and sensitive detection methods which can be applied in research laboratory setups and in field for routine diagnosis. Paper lateral flow biosensors (LFBs) have been established as attractive tools for such analytical applications. In the present study a prototype LFB was designed for whole particles (virions) detection of nodavirus or fish nervous necrosis virus.

Transcriptome Analysis Identifies Immune Markers Related to Visceral Leishmaniasis Establishment in the Experimental Model of BALB/c Mice.

Visceral leishmaniasis (VL) caused by and . is a potentially fatal disease. To date there are no registered vaccines for disease prevention despite the fact that several vaccines are in preclinical development.

Detection of Antigen-specific T cells in Spleens of Vaccinated Mice Applying [H]-Thymidine Incorporation Assay and Luminex Multiple Cytokine Analysis Technology.

For many infectious diseases T cells are an important part of naturally acquired protective immune responses, and inducing these by vaccination has been the aim of much research. Here, we describe a protocol for the analysis of vaccine-induced antigen-specific immune responses. For this purpose, cells of whole spleens obtained from vaccinated BALB/c mice were stimulated with the antigen incorporated in the vaccine.

Induction of protective cellular immune responses against experimental visceral leishmaniasis mediated by dendritic cells pulsed with the N-terminal domain of Leishmania infantum elongation factor-2 and CpG oligodeoxynucleotides.

Leishmania elongation factor 2 (EF-2) has been previously identified as a T1-stimulatory protein. In this study, we assayed the protective potential of the N-terminal domain of EF-2 (N-LiEF-2, 1-357 aa) that has been predicted to contain several overlapping MHC class I and II-restricted epitopes injected in the form of dendritic cell (DC)-based vaccine. Ex vivo pulsing of DCs with the recombinant N-LiEF-2 domain along with CpG oligodeoxynucleotides (ODNs) resulted in their functional differentiation.

Towards a Dual Lateral Flow Nanobiosensor for Simultaneous Detection of Virus Genotype-Specific PCR Products.

Nervous necrosis virus (nodavirus) has been responsible for mass mortalities in aquaculture industry worldwide, with great economic and environmental impact. A rapid low-cost test to identify nodavirus genotype could have important benefits for vaccine and diagnostic applications in small- and medium-scale laboratories in both academia and fish farming industry. A dual lateral flow biosensor for simultaneous detection of the most prevalent nodavirus genotypes (RGNNV and SJNNV) was developed and optimized.

Vaccination with poly(D,L-lactide-co-glycolide) nanoparticles loaded with soluble antigens and modified with a TNFα-mimicking peptide or monophosphoryl lipid A confers protection against experimental visceral leishmaniasis.

Visceral leishmaniasis (VL) persists as a major public health problem, and since the existing chemotherapy is far from satisfactory, development of an effective vaccine emerges as the most appropriate strategy for confronting VL. The development of an effective vaccine relies on the selection of the appropriate antigen and also the right adjuvant and/or delivery vehicle. In the present study, the protective efficacy of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs), which were surface-modified with a TNFα-mimicking eight-amino-acid peptide (p8) and further functionalized by encapsulating soluble antigens (sLiAg) and monophosphoryl lipid A (MPLA), a TLR4 ligand, was evaluated against challenge with parasites in BALB/c mice.

A Poly(Lactic--Glycolic) Acid Nanovaccine Based on Chimeric Peptides from Different Proteins Induces Dendritic Cells Maturation and Promotes Peptide-Specific IFNγ-Producing CD8 T Cells Essential for the Protection against Experimental Visceral Leishmaniasis.

Visceral leishmaniasis, caused by (.) and protozoan parasites, can provoke overwhelming and protracted epidemics, with high case-fatality rates. An effective vaccine against the disease must rely on the generation of a strong and long-lasting T cell immunity, mediated by CD4 T and CD8 T cells.

Genotype-specific real-time PCR combined with high-resolution melting analysis for rapid identification of red-spotted grouper nervous necrosis virus.

A real-time genotype-specific polymerase chain reaction (PCR) assay combined with high-resolution melting (HRM) analysis was developed to assess the most common genotypes of nervous necrosis viruses or nodaviruses. Nodaviruses are the causal agents of viral nervous necrosis infections, which have been wreaking havoc in the aquaculture industry worldwide, with fish mortality up to 100%. The four different genotypes of nodaviruses correlate with differences in viral pathogenicity.

Identification of BALB/c Immune Markers Correlated with a Partial Protection to Leishmania infantum after Vaccination with a Rationally Designed Multi-epitope Cysteine Protease A Peptide-Based Nanovaccine.

Background: Through their increased potential to be engaged and processed by dendritic cells (DCs), nanovaccines consisting of Poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with both antigenic moieties and adjuvants are attractive candidates for triggering specific defense mechanisms against intracellular pathogens. The aim of the present study was to evaluate the immunogenicity and prophylactic potential of a rationally designed multi-epitope peptide of Leishmania Cysteine Protease A (CPA160-189) co-encapsulated with Monophosphoryl lipid A (MPLA) in PLGA NPs against L. infantum in BALB/c mice and identify immune markers correlated with protective responses.

Gold nanoparticle-based lateral flow biosensor for rapid visual detection of Leishmania-specific DNA amplification products.

Leishmaniasis is a disease, caused by Leishmania parasites, which infect humans and animals, posing a major social and economic burden worldwide. The need for accurate and sensitive disease diagnosis led to the widespread adoption of PCR amplification. Detection of the amplification products (i.

PLGA nanoparticles modified with a TNFα mimicking peptide, soluble Leishmania antigens and MPLA induce T cell priming in vitro via dendritic cell functional differentiation.

Poly(lactide-co-glycolide) nanoparticles (PLGA NPs) represent a new approach for vaccine delivery due to their ability to be taken up by phagocytes and to activate immune responses. In the present study PLGA NPs were surface-modified with a TNFα mimicking peptide, and encapsulated soluble Leishmania antigens (sLiAg) and MPLA adjuvant. The synthesized PLGA NPs exhibited low cytotoxicity levels, while surface-modified NPs were more efficiently taken up by dendritic cells (DCs).