Selective depletion of regulatory T cells enhances the immunogenicity of a recombinant-based vaccine against spp.

Introduction: Regulatory T cells (Tregs) have been shown to limit the protective immune response against pathogenic species of the fungus spp, the causal agent of sporotrichosis. However, the specific function of Tregs during vaccination against these fungi is known.

Methods: We evaluated the effect of Tregs depletion on the immunogenicity of an experimental recombinant anti- vaccine, using the DEREG mice.

A Sporothrix spp. enolase derived multi-epitope vaccine confers protective response in BALB/c mice challenged with Sporothrix brasiliensis.

Sporotrichosis is a cosmopolitan mycosis caused by pathogenic species of Sporothrix genus, that in Brazil is often acquired by zoonotic transmission involved infected cats with S. brasiliensis. Previous studies showed that the Sporothrix spp.

Foxp3 Silencing with Antisense Oligonucleotide Improves Immunogenicity of an Adjuvanted Recombinant Vaccine against .

Background: In recent years, there has been great interest in developing molecular adjuvants based on antisense oligonucleotides (ASOs) targeting immunosuppressor pathways with inhibitory effects on regulatory T cells (Tregs) to improve immunogenicity and vaccine efficacy. We aim to evaluate the immunostimulating effect of 2'OMe phosphorothioated Foxp3-targeted ASO in an antifungal adjuvanted recombinant vaccine.

Methods: The uptake kinetics of Foxp3 ASO, its cytotoxicity and its ability to deplete Tregs were evaluated in murine splenocytes in vitro.

Transient Foxp3(+) regulatory T-cell depletion enhances protective Th1/Th17 immune response in murine sporotrichosis caused by Sporothrix schenckii.

The role of regulatory T cells (Tregs) on protective immunity in fungal infections, is controversial. Sporotrichosis is an emerging and worldwide-distributed subcutaneous mycosis caused by various related thermodimorphic fungi of the genus Sporothrix. Previously, we showed an elevated percent of Tregs around 21 days post-infection (dpi) in C57BL/6 mice infected with either Sporothrix schenckii or Sporothrix brasiliensis, but the effect of these cells in the ongoing infection was not evaluated.

Progress in the Use of Antisense Oligonucleotides for Vaccine Improvement.

Antisense oligonucleotides (ASOs) are synthetically prepared short single-stranded deoxynucleotide sequences that have been validated as therapeutic agents and as a valuable tool in molecular driving biology. ASOs can block the expression of specific target genes via complementary hybridization to mRNA. Due to their high specificity and well-known mechanism of action, there has been a growing interest in using them for improving vaccine efficacy.

Immunization with recombinant enolase of Sporothrix spp. (rSsEno) confers effective protection against sporotrichosis in mice.

In recent years, research has focused on the immunoreactive components of the Sporothrix schenckii cell wall that can be relevant targets for preventive and therapeutic vaccines against sporotrichosis, an emergent worldwide mycosis. In a previous study, we identified a 47-kDa enolase as an immunodominant antigen in mice vaccinated with an adjuvanted mixture of S. schenckii cell wall proteins.

Prophylactic and therapeutic vaccines against sporotrichosis. Feasibility and prospects.

Sporotrichosis is an emergent subcutaneous mycosis of humans and some animals caused by dimorphic fungi of the genus Sporothrix. The disease occurs worldwide but is endemic or hyperendemic in tropical and subtropical areas. The epidemiology of the disease is changing dramatically, and it is now considered an important zoonosis with high morbidity rates, principally in Brazil, and an opportunistic infection in immunocompromised patients.

A Recombinant Enolase-Montanide™ PetGel A Vaccine Promotes a Protective Th1 Immune Response against a Highly Virulent by Toluene Exposure.

The effect of vaccination in fungal strains that suffered changes in their virulence by exposure to environmental contaminants is largely known. Growing reports of resistance to antifungal drugs and the emergence of new highly virulent strains, possibly acquired in the environment, prompt the design of new vaccines able to prevent and combat emerging mycotic diseases. In this study, we evaluated the protective capacity of an enolase-based vaccine and Montanide PetGel A (PGA) as an adjuvant against with increased virulence by exposure to toluene.

Sporothrix brasiliensis induces a more severe disease associated with sustained Th17 and regulatory T cells responses than Sporothrix schenckii sensu stricto in mice.

Little is known about the differences in the CD4+ T-cell response induced by Sporothrix schenckii and Sporothrix brasiliensis, the most virulent species that cause sporotrichosis. Here, the helper (Th) and regulatory T cells (Tregs) responses were evaluated comparatively in a murine model of sporotrichosis on days 7, 21 and 35 after subcutaneous infection with either S. schenckii or S.

Efficacy and safety of immunological adjuvants. Where is the cut-off?

Research over the past several decades has provided insight into the mode of action of adjuvants. However, the main focus of attention has been the efficacy in the induction of protective immunogenicity, while less effort has been devoted to the study of toxicity mechanisms. Evidences suggest that several mechanisms that are responsible for the immunostimulating effects are, at the same time, responsible of the adverse effects.

Repeated Exposition to Mercury (II) Chloride Enhances Susceptibility to Infection in Mice.

Sporotrichosis is a subcutaneous mycosis that has re-emerged in several tropical and subtropical regions over the last decades. Growing findings suggest that the interplay of host, pathogen, and environment has a determinant effect on the diversity, local distribution, and virulence of , the etiologic agent. Among the environmental factors, we have studied the potential role of repeated exposures to mercury (Hg), a known immunotoxic xenobiotic that is widely used in gold mining regions where sporotrichosis outbreaks are frequently reported.

Molecular adjuvants that modulate regulatory T cell function in vaccination: A critical appraisal.

Adjuvants are substances used to enhance the efficacy of vaccines. They influence the magnitude and alter the quality of the adaptive immune response to vaccine antigens by amplifying or modulating different signals involved in the innate immune response. The majority of known adjuvants have been empirically identified.

Comparative efficacy and toxicity of two vaccine candidates against Sporothrix schenckii using either Montanide™ Pet Gel A or aluminum hydroxide adjuvants in mice.

Sporotrichosis is an important zoonosis in Brazil and the most frequent subcutaneous mycosis in Latin America, caused by different Sporothrix species. Currently, there is no effective vaccine available to prevent this disease. In this study, the efficacy and toxicity of the adjuvant Montanide™ Pet Gel A (PGA) formulated with S.

[Autoimmune/inflammatory syndrome induced by adjuvants. A new clinical entity?].

Recently Shoenfeld and Agmon-Levin proposed a new clinical entity called autoimmune/inflammatory syndrome induced by adjuvants (ASIA), which includes four clinical entities called: 1) siliconosis, 2) Gulf War syndrome, 3) macrophage myofasciitis) and 4) post-vaccination phenomenon associated with adjuvants. They all have a common denominator: a prior exposure to immunoadjuvants, and, in addition, they also share several clinical criteria associated to chronic inflammation and autoimmune reactions. This proposal still needs to be validated by the scientific community, but nowadays is a topic of hot discussion in the literature and in various international conferences.

The Hen's Egg Test on Chorioallantoic Membrane: An Alternative Assay for the Assessment of the Irritating Effect of Vaccine Adjuvants.

Local reactions are the most frequent adverse event associated with vaccines. Adjuvants are major constituents of many vaccines and they are frequently involved in these reactions, associated with their irritating effect and the stimulation of local inflammation. The hen's egg test on chorioallantoic membrane (HET-CAM) is an alternative toxicological method widely used to determine ocular irritation potential, but very few studies have demonstrated the utility of this method for assessing the irritant properties of vaccine adjuvants.

A cell wall protein-based vaccine candidate induce protective immune response against Sporothrix schenckii infection.

Sporotrichosis is a subcutaneous mycosis caused by several closely related thermo-dimorphic fungi of the Sporothrix schenckii species complex, affecting humans and other mammals. In the last few years, new strategies have been proposed for controlling sporotrichosis owning to concerns about its growing incidence in humans, cats, and dogs in Brazil, as well as the toxicity and limited efficacy of conventional antifungal drugs. In this study, we assessed the immunogenicity and protective properties of two aluminum hydroxide (AH)-adsorbed S.