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Bovine herpesvirus-1 (BoHV-1) uses many mechanisms to elude the immune system; one of them is spreading intracellularly, even in the presence of specific antiviral antibodies. Cytotoxic T lymphocytes (CTLs) are necessary to eliminate the virus. The main preventive strategy is vaccination based on inactivated virus. These vaccines are poor inducers of cellular immune responses, and complicate serological diagnosis and determination of the real prevalence of infection. DNA vaccines are a good option because of the capacity of Differentiating Infected from Vaccinated Animals-(DIVA vaccine)-and may be the best way to induce cytotoxic responses. Although this type of vaccines leads to only weak "

Protection against foot-and-mouth disease virus (FMDV) has been linked to the development of a humoral response. In Argentina, the official control tests for assessing the potency of FMD vaccines are protection against podal generalization (PPG) and expected percentage of protection (EPP) curves built with quantitative data of antibodies determined by liquid-phase blocking ELISA (lpELISA). The results of these tests are used to accept or discard vaccines at the batch level. In this report, a mouse model was assessed as an alternative efficacy control for FMDV vaccines. To this aim, groups of cattle (n = 18) and BALB/c mice (n = 16) were inoculated with commercial FMDV vaccines and bleedings were performed 60 days post vaccination (dpv) in cattle and 21 dpv in mice. Specific FMDV antibody titres were measured in both species by a standardized lpELISA. A statistically significant association between antibody levels in cattle and mice has already been demonstrated. However, some vaccines have been misclassified since they were considered protective based on lpELISA results but did not induce good protection in cattle upon challenge. For this reason, other immunological parameters were evaluated to improve the prediction of protection in mice, without the need of using infective virus. In addition, antibody titres by lpELISA, the IgG2b/IgG1 isotype ratio and the Avidity Index were identified as good predictors, resulting in an optimal predictive model of protection. This mouse model could be a simple and economic alternative for testing FMD vaccines since the disadvantages of high costs and facility requirements associated with the use of large animals are overcome. Fil: Gnazzo, Victoria. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Quattrocchi, Valeria. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Soria, Ivana. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Pereyra, Erica Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Langellotti, Cecilia Ana. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Pedemonte, Andrea. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: López, Virginia. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Marangunich, Laura. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Zamorano, Patricia Ines. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina

Foot and Mouth Disease Virus (FMDV) causes economy losses and is controlled by vaccination in many countries. Vaccine formulations based on empty capsids or Virus-Like Particles (VLPs) have the advantage of avoiding the biological hazard of using infectious FMDV, albeit are poorly immunogenic. Recently, we have described that ISPA a new Immune Stimulating Complex adjuvant, is useful to improve the response against FMD of vaccines that use inactivated virus. Now, the adjuvant effects of ISPA and ISA 206 (water/oil/water) on a VLPs-based FMD vaccine were evaluated. VLPs (strain A/Argentina/2001) were obtained in mammalian cell cultures and their elicitation of an immune response against FMDV with and without ISPA or ISA 206 was evaluated in mice as a first approach. Notably, VLPs-ISPA and VLPs-ISA 206 vaccines induced protection against viral challenge in 100 % of mice, while protection induced by VLPs alone was of 40 %. Total and neutralizing FMDV antibodies were higher in the VLPs-ISPA and VLPs-ISA 206 groups compared to the VLPs group. VLPs-ISPA induced significantly higher (p < 0.001) IgG1, IgG2a, IgG2b and IgG3 titers than the VLPs vaccine. Moreover, in comparison with non-adjuvanted VLPs, VLPs-ISPA and VLPs-ISA 206 elicited an increased virus-specific T response, including higher IFNγ+/CD8 + lymphocyte production in mice. When these vaccines were tested in calves, antibody titers reached an Expected Percentage of Protection (EPP) above 90 % in the case of the VLPs-ISPA and VLPs-ISA 206 vaccines, while, in the VLPs group, EPP reached 25 %. IFNγ levels secreted by mononuclear cells of VLP-ISPA-vaccinated cattle were significantly higher than in the VLPs group. Overall, the results demonstrate that VLPs-ISPA or VLPs-ISA 206 are promising formulations for the development of a novel FMD vaccine.

Dendritic cells serve as the main immune cells that trigger the immune response. We developed a simple and cost-effective nanovaccine platform based on the α1',2-mannobiose derivative for dendritic cell targeting. In previous work, we have formulated the α1,2-mannobiose-based nanovaccine platform with plasmid DNA and tested it in cattle against BoHV-1 infection. There, we have shown that the dendritic cell targeting using this nanovaccine platform in vivo can boost the immunogenicity, resulting in a long-lasting immunity. In this work, we aim to characterize the α1',2-mannobiose derivative, which is key in the nanovaccine platform. This DC-targeting strategy takes advantage of the specific receptor known as DC-SIGN and exploits its capacity to bind α1,2-mannobiose that is present at terminal ends of oligosaccharides in certain viruses, bacteria, and other pathogens. The oxidative conjugation of α1',2-mannobiose to NH2-PEG2kDa-DSPE allowed us to preserve the chemical structure of the non-reducing mannose of the disaccharide and the OH groups and the stereochemistry of all carbons of the reducing mannose involved in the binding to DC-SIGN. Here, we show specific targeting to DC-SIGN of decorated micelles incubated with the Raji/DC-SIGN cell line and uptake of targeted liposomes that took place in human, bovine, mouse, and teleost fish DCs in vitro, by flow cytometry. Specific targeting was found in all cultures, demonstrating a species-non-specific avidity for this ligand, which opens up the possibility of using this nanoplatform to develop new vaccines for various species, including humans.

New technologies in the field of vaccinology arise as a necessity for the treatment and control of many diseases. Whole virus inactivated vaccines and modified live virus ones used against Bovine Herpesvirus-1 (BoHV-1) infection have several disadvantages. Previous works on DNA vaccines against BoHV-1 have demonstrated the capability to induce humoral and cellular immune responses. Nevertheless, ‘naked’ DNA induces low immunogenic response. Thus, loading of antigen encoding DNA sequences in liposomal formulations targeting dendritic cell receptors could be a promising strategy to better activate these antigen-presenting cells (APC). In this work, a DNA-based vaccine encoding the truncated version of BoHV-1 glycoprotein D (pCIgD) was evaluated alone and encapsulated in a liposomal formulation containing LPS and decorated with MANα1-2MAN-PEG-DOPE (pCIgD-Man-L). The vaccinations were performed in mice and bovines. The results showed that the use of pCIgD-Man-L enhanced the immune response in both animal models. For humoral immunity, significant differences were achieved when total antibody titres and isotypes were assayed in sera. Regarding cellular immunity, a significant increase in the proliferative response against BoHV-1 was detected in animals vaccinated with pCIgD-Man-L when compared to the response induced in animals vaccinated with pCIgD. In addition, upregulation of CD40 molecules on the surface of bovine dendritic cells (DCs) was observed when cells were stimulated and activated with the vaccine formulations. When viral challenge was performed, bovines vaccinated with MANα1-2MAN-PEG-DOPE elicited better protection which was evidenced by a lower viral excretion. These results demonstrate that the dendritic cell targeting using MANα1-2MAN decorated liposomes can boost the immunogenicity resulting in a long-lasting immunity. Liposomes decorated with MANα1-2MAN-PEG-DOPE were tested for the first time as a DNA vaccine nanovehicle in cattle as a preventive treatment against BoHV-1. These results open new perspectives for the design of vaccines for the control of bovine rhinotracheitis. Fil: Kornuta, Claudia Alejandra. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; Argentina Fil: Bidart, Juan Esteban. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; Argentina Fil: Soria, Ivana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; Argentina Fil: Gammella, Mariela Vanesa. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; Argentina Fil: Quattrocchi, Valeria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; Argentina Fil: Pappalardo, Juan Sebastian. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina Fil: Salmaso, Stefano. Università di Padova; Italia Fil: Torchilin, Vladimir P. Northeastern University; Estados Unidos Fil: Cheuquepán Valenzuela, Felipe Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Hecker, Yanina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Moore, Dadin Prando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Zamorano, Patricia Ines. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; Argentina Fil: Langellotti, Cecilia Ana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Instituto de Virología E Innovaciones Tecnológicas; Argentina

DNA vaccines are capable of inducing humoral and cellular immunity, and are important to control bovine herpesvirus 1 (BoHV-1), an agent of the bovine respiratory disease complex. In previous work, a DNA plasmid that encodes a secreted form of BoHV-1 glycoprotein D (pCIgD) together with commercial adjuvants provided partial protection against viral challenge of bovines. In this work, we evaluate new molecules that could potentiate the DNA vaccine. We show that a plasmid encoding a soluble CD40 ligand (CD40L) and the adjuvant Montanide™ GEL01 (GEL01) activate in vitro bovine afferent lymph dendritic cells (ALDCs). CD40L is a co-stimulating molecule, expressed transiently on activated CD4+ T cells and, to a lesser extent, on activated B cells and platelets. The interaction with its receptor, CD40, exerts effects on the presenting cells, triggering responses in the immune system. GEL01 was designed to improve transfection of DNA vaccines. We vaccinated cattle with: pCIgD; pCIgD-GEL01; pCIgD with GEL01 and CD40L plasmid (named pCIgD-CD40L-GEL01) or with pCIneo vaccines. The results show that CD40L plasmid with GEL01 improved the pCIgD DNA vaccine, increasing anti-BoHV-1 total IgGs, IgG1, IgG2 subclasses, and neutralizing antibodies in serum. After viral challenge, bovines vaccinated with pCIgD-GEL01-CD40L showed a significant decrease in viral excretion and clinical score. On the other hand, 80% of animals in group pCIgD-GEL01-CD40L presented specific anti-BoHV-1 IgG1 antibodies in nasal swabs. In addition, PBMCs from pCIgD-CD40L-GEL01 had the highest percentage of animals with a positive lymphoproliferative response against the virus and significant differences in the secretion of IFNγ and IL-4 by mononuclear cells, indicating the stimulation of the cellular immune response. Overall, the results demonstrate that a plasmid expressing CD40L associated with the adjuvant GEL01 improves the efficacy of a DNA vaccine against BoHV-1.

Foot-and-Mouth Disease Virus (FMDV) causes an acute disease with important economy losses worldwide. Currently available vaccines are based on inactivated FMDV and oil-adjuvants. The use of Virus-Like Particles (VLPs) for subunit vaccines has been reported to be promising since it avoids the biological hazard of using virus in vaccine production while conserving conformational viral epitopes. However, a more efficient and cost-effective adjuvant than those currently used is needed. Immunostimulant-Particle Adjuvant (ISPA) is an Immune Stimulating Complex (ISCOM) - type adjuvant formulated with dipalmitoyl-phosphatidylcholine, cholesterol, stearylamine, alpha tocopherol and QuilA. In the present work, we have evaluated the immune response against FMDV using VLPs and ISPA as adjuvant. VLPs (serotype A/Arg/01) were obtained by transient gene expression in mammalian cell cultures, and a previously developed murine model, able to predict the ability of a vaccine to induce protection in cattle, was used for vaccination experiments in a first approach. The VLPs-ISPA vaccine induced protection in mice against challenge and elicited a specific antibody response in sera. In a second approach, the VLPs-ISPA vaccine was tested in calves. Interestingly one vaccine dose was enough to induce total α-FMDV antibodies , as measured by ELISA, as well as neutralizing Abs. Antibody titers reached an Expected Percentage of Protection higher than 90%. The EPP index calculates the probability that livestock will be protected against a challenge of 10.000 bovine infectious doses after vaccination. Moreover, IFN-γ levels secreted in vitro by mononuclear cells of VLP-ISPA vaccinated animals were significantly higher (p

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals that causes severe economic losses in the livestock industry. Currently available vaccines are based on the inactivated FMD virus (FMDV). Although inactivated vaccines have been effective in controlling the disease, they have some disadvantages. Because of these disadvantages, investigations are being made to produce vaccines in low containment facilities. The use of recombinant empty capsids (also referred as Virus Like Particles, VLPs) has been reported to be a promising candidate as a subunit vaccine because it avoids the use of virus in the vaccine production and conserves the conformational epitopes of the virus. Mignaqui and collaborators have produced recombinant FMDV empty capsids from serotype A/ARG/2001 using a scalable technology in mammalian cells that elicited a protective immunity against viral challenge in a mouse model. However, further evaluation of the immune response elicited by these VLPs in cattle is required. In the present work we compare the effect that VLPs or inactivated FMDV has on bovine dendritic cells and the humoral response elicited in cattle after a single vaccination., yes

Foot-and-Mouth Disease (FMD) is an acute viral disease that causes important economy losses. Vaccines with new low-cost adjuvants that stimulate protective immune responses are needed and can be assayed in a mouse model to predict their effectiveness in cattle. Immunostimulant Particle Adjuvant (ISPA), also known as cage-like particle adjuvant, consisting of lipid boxes of dipalmitoyl-phosphatidylcholine, cholesterol, sterylamine, alpha-tocopherol, and QuilA saponin, was shown to enhance protection of a recombinant vaccine against Trypanosoma cruzi in a mouse model. Thus, in the present work, we studied the effects on the magnitude and type of immunity elicited in mice and cattle in response to a vaccine based on inactivated FMD virus (iFMDV) formulated with ISPA. It was demonstrated that iFMDV–ISPA induced protection in mice against challenge and elicited a specific antibody response in sera, characterized by a balanced Th1/Th2 profile. In cattle, the antibody titers reached corresponded to an expected percentage of protection (EPP) higher than 80%. EPP calculates the probability that livestock would be protected against a 10,000 bovine infectious doses challenge after vaccination. Moreover, in comparison with the non-adjuvanted iFMDV vaccine, iFMDV–ISPA elicited an increased specific T-cell response against the virus, including higher interferon gamma (IFNγ)+/CD8+ lymphocyte production in cattle. In this work, we report for first time that an inactivated FMDV serotype A vaccine adjuvanted with ISPA is capable of inducing protection against challenge in a murine model and of improving the specific immune responses against the virus in cattle. Fil: Bidart, Juan Esteban. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Kornuta, Claudia Alejandra. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Gammella, Mariela Vanesa. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Gnazzo, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina Fil: Soria, Ivana. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Langellotti, Cecilia Ana. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Mongini, Claudia. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Galarza, Roxana. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Buenos Aires Sur. Estacion Experimental Agropecuaria Cuenca del Salado. Agencia de Extension Rural Chascomus.; Argentina Fil: Calvinho, Luis Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina Fil: Lupi, Giuliana Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; Argentina Fil: Quattrocchi, Valeria. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina Fil: Marcipar, Iván Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; Argentina Fil: Zamorano, Patricia Ines. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Virologia E Innovaciones Tecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Virologia E Innovaciones Tecnologicas.; Argentina

Surface proteins bound to the cell membrane by glycosylphosphatidylinositol (GPI) anchors are considered essential for the survival of pathogenic protozoans. In the case of the tick-transmitted hemoparasite Babesia bovis, the most virulent causative agent of bovine babesiosis, the GPI-anchored proteome was recently unraveled by an in silico approach. In this work, one of the identified proteins, GASA-1 (GPI-Anchored Surface Antigen-1), was thoroughly characterized. GASA-1 is 179 aa long and has the characteristic features of a GPI-anchored protein, including a signal peptide, a hydrophilic core and a hydrophobic tail that harbors a GPI anchor signal. Transcriptomic analysis shows that it is expressed in pathogenic and attenuated B. bovis strains. Notably, the gasa-1 gene has syntenic counterparts in B. bigemina and B. ovata, which also encode GPI-anchored proteins. This is highly unusual since all piroplasmid GPI-anchored proteins described so far have been found to be species-specific. Sequencing of gasa-1 alleles from B. bovis geographical isolates originating from Argentina, USA, Brazil, Mexico and Australia showed over 98 % identity in both nucleotide and amino acid sequences. A recombinant form of GASA-1 (rGASA-1) was generated in E. coli and anti-rGASA-1 antibodies were raised in mice. Fixed and live immunofluorescence assays showed that GASA-1 is expressed in in vitro cultured B. bovis merozoites and surface-exposed. Moreover, incubation of B. bovis in vitro cultures with anti-GASA-1 antibodies partially, but significantly, reduced erythrocyte invasion, indicating that this protein bears neutralization-sensitive antibody epitopes. Splenocytes of rGASA-1-inoculated mice showed a specific proliferative response when exposed to the recombinant protein, indicating that GASA-1 bears T-cell epitopes. Finally, sera from a group of B. bovis-infected cattle reacted with the recombinant protein, demonstrating that GASA-1 is expressed during natural infection of bovines with B. bovis, and suggesting that it is immunodominant. The high degree of conservation among B. bovis isolates and the presence of syntenic genes in other Babesia species suggest a relevant role of GASA-1 and GASA-1-like proteins for parasite survival, especially considering that, due to their surface location, they are exposed to the selection pressure of the host immune system. The highlighted features of GASA-1 make it an interesting candidate for the development of vaccines against bovine babesiosis.

Foot and mouth disease is an acute disease of cattle with a broad distribution around the world. Due to the fast spread of FMDV infections, control measures must be applied immediately after an outbreak, such as the use of vaccines that induce fast protection. Previously, it was shown that mice vaccinated with FMD inactivated virus (iFMDV) formulated with Montanide™ ESSAI IMS D 12802 VG PR adjuvant (802-iFMDV) were protected when they were challenged 4 and 7 days post-vaccination (dpv) with homologous virus. In this work, we describe the successful use of this formulation in cattle. In addition, adjuvant Montanide™ IMS 1313 VG NPR was also tested. 802-iFMDV vaccine was able to confer 100% protection against viral challenge at 4 and 7 dpv, while eliciting low antibody levels, at 7 dpv. 1313-iFMDV vaccine induced protection in 60% of cattle. At 4 dpv, 1313-iFMDV vaccinated animals presented increased levels of IFNγ but not of macrophages. At 4 and 7 dpv, macrophages, IFNγ, nasal IgA and IgG1 antibodies against FMDV, and opsonophagocytosis were increased in animals vaccinated with 802-iFMDV indicating that these phenomena could be involved in protection.It is the first time that total protection against FMDV at early stages post-vaccination is reported using a single dose of the formulation iFMDV plus Montanide™ ESSAI D IMS 12802 VG PR adjuvant. Fil: Quattrocchi, Valeria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Pappalardo, Juan Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Langellotti, Cecilia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Smitsaart, E.. Biogénesis Bagó S.A.; Argentina Fil: Fondevila, Norberto Antonio. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Zamorano, Patricia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Universidad del Salvador; Argentina

Bovine herpesvirus-1 (BoHV-1) is the causative agent of bovine infectious rhinotracheitis, an important disease worldwide. Although conventional BoHV-1 vaccines, including those based on the use of modified live virus and also inactivated vaccines, are currently used in many countries, they have several disadvantages. DNA vaccines have emerged as an attractive approach since they have the potential to induce both humoral and cellular immune response; nevertheless, it is largely known that potency of naked DNA vaccines is limited. We demonstrated previously, in the murine model, that the use of adjuvants in combination with a DNA vaccine against BoHV-1 is immunologically beneficial. In this study, we evaluate the immune response and protection against challenge elicited in bovines, by a DNA vaccine carrying the sequence of secreted version of glycoprotein D (gD) of BoHV-1 formulated with chemical adjuvants. Bovines were vaccinated with formulations containing the sequence of gD alone or in combination with adjuvants ESSAI 903110 or Montanide™ 1113101PR. After prime vaccination and two boosters, animals were challenged with infectious BoHV-1. Formulations containing adjuvants Montanide™ 1113101PR and ESSAI 903110 were both, capable of increasing humoral immune response against the virus and diminishing clinical symptoms. Nevertheless, only formulations containing adjuvant Montanide™ 1113101PR was capable of improving cellular immune response and diminishing viral excretion. To our knowledge, it is the first time that a BoHV-1 DNA vaccine is combined with adjuvants and tested in cattle. These results could be useful to design a vaccine for the control of bovine rhinotracheitis. Fil: Quattrocchi, Valeria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Soria, Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Langellotti, Cecilia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gnazzo, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gammella, Mariela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Moore, Dadin Prando. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Zamorano, Patricia Ines. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Universidad del Salvador; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Baculoviruses (Bvs) potentiate the immune response against soluble antigens. We investigated whether Bv could be used as immunoactivator in foot-and-mouth disease (FMD) vaccines using the BALB/c mouse model. Mice were vaccinated with a single dose of inactivated FMDV (iFMDV), iFMDV. +. Bv, Bv, or culture medium. Humoral and cellular immune responses were higher in animals immunized with iFMDV. +. Bv than in mice vaccinated with iFMDV alone. Animals receiving iFMDV. +. Bv had significantly lower viremia at 2, 4 and 7. dpv, than those immunized with iFMDV alone. In order to prolong the immune response, iFMDV oil vaccine was co-inoculated with Bv. Animals receiving iFMDV oil vaccine. +. Bv were protected two days earlier than those receiving the iFMDV oil vaccine alone. Both formulations protected until 14. dpv, the last day of the experiment.This is the first report in which Bv is used as an adjuvant in a FMDV vaccine. Fil: Quattrocchi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Molinari, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad del Salvador; Argentina Fil: Langellotti, Cecilia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad del Salvador; Argentina Fil: Gnazzo, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad del Salvador; Argentina Fil: Taboga, Oscar Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Zamorano, Patricia Ines. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Foot-and-mouth disease (FMD) is a highly contagious and acute viral disease of cloven-hoofed animals. From an economical point of view, it is the most important disease of livestock worldwide. It is known that the virus interacts with dendritic cells, both in the natural host and in mice, but the impact of this interaction on the adaptive immune response is controversial. Currently available vaccines are based on inactivated forms of the FMD virus. Little is known about the differences between infectious and inactivated virus, in terms of dendritic cell subsets involved in immune response activation. The present work, which was carried out in the murine model, shows that live virus infection induces a reduction in splenic dendritic cell subsets. In addition, lymphocyte proliferation is inhibited in the early stages of infection associated with IFN-α induction, but is restored to normal values 5 days post-infection when pro-inflammatory cytokines was produced. In contrast, the inactivated virus increases the percentage of plasmacytoid dendritic cells in the spleen and the production of IL-10, which triggers the activation of a T regulatory response.

Summary Leukotriene C4 is an important mediator in the development of inflammatory reactions and ischaemia. Previous studies have shown that leukotriene C4 is able to modulate the function of dendritic cells (DCs) and induce their chemotaxis from skin to lymph node. In this study, we decided to evaluate the modulation exerted by leukotriene C4 on DCs, depending on their status of activation. We showed for the first time that leukotriene C4 stimulates endocytosis both in immature and lipopolysaccharide (LPS) -activated DCs. Moreover, it suppressed the interleukin-12p70 (IL-12p70) release, but induces the secretion of IL-23 by DCs activated with LPS and promotes the expansion of T helper type 17 (Th17) lymphocytes. Furthermore, blocking the release of IL-23 reduced the percentages of CD4+ T cells producing IL-17 in a mixed lymphocyte reaction. Ours results suggest that leukotriene C4 interferes with the complete maturation of inflammatory DCs in terms of phenotype and antigen uptake, while favouring the release of IL-23, the main cytokine involved in the maintenance of the Th17 profile.

Foot and Mouth Disease (FMD) is an acute disease caused by Foot and Mouth Disease Virus (FMDV) which causes important economy losses, this is why it is necessary to obtain a vaccine that stimulates a rapid and long-lasting protective immune response. Cliptox is a mineral microparticle that in earlier studies has shown adjuvant activity against different antigens. In this study we have examined the effects of Cliptox on the magnitude and type of immunity elicited in response to inactivated FMDV (iFMDV) vaccine. It was demonstrated that iFMDV-Cliptox stimulates a specific antibody response detected in mucosal and in sera. The different isotype profiles elicited by inoculation with this vaccine indicate a Th1/Th2 response. Also, an increase in dendritic cells and macrophages in the spleen in comparison with the iFMDV vaccine iFMDV-Cliptox was detected. The Cliptox-iFMDV formulation was non toxic by using egg embryos and yielded increased protection against challenge with FMDV in the murine model. Our results show that the incorporation of Cliptox into FMDVi vaccine induces an increase of the specific protective immune response in mice and clearly indicate that Cliptox TM exert an (important) up-regulation on DC and MPhi. Additionally, Cliptox TM adjuvant can be used in vaccines for induction of mucosal immune response.

Histamine controls the function of dendritic cells (DCs). It appears to be required for the normal development of DCs. It also induces the chemotaxis of immature DCs and promotes the differentiation of CD4(+) T cells into cells with a T helper type 2 (Th2) profile. Moreover, we have recently shown that histamine stimulates both the uptake and the cross-presentation of antigens by DCs, supporting the theory that histamine promotes activation of CD8(+) T cells during the development of allergic pathologies. Here, we investigated whether the course of an allergic response, in a well-defined model of ovalbumin (OVA)-induced allergic airway inflammation, could be modulated by intratracheal injection of OVA-pulsed DCs previously treated with histamine (DCHISs). Compared with control DCs, DCHISs induced: (i) greater recruitment of CD8(+) T cells in the lung, (ii) greater stimulation of the production of interleukin (IL)-5 by lung CD8(+) T cells, and (iii) increased recruitment of CD11c/CD8 double-positive DCs in the lungs of allergic mice. Moreover, mice treated with DCHISs showed increased levels of serum-specific immunoglobulin E (IgE) antibodies directed to OVA, and a higher proportion of eosinophils in bronchoalveolar lavage (BAL) compared with mice treated with OVA-pulsed control DCs. Our results support the notion that histamine, by acting on DCs, increases the severity of allergic processes.

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals. This pathol-ogy is caused by foot-and-mouth disease virus (FMDV). Over time, the development of vaccines to preventthe spread of this illness became essential. Vaccines currently used contain the inactivated form of thevirus. However, vaccination generates an immune response different to that induced by the infection. Weinvestigated whether these differences are related to intracellular mechanisms on dendritic cells (DCs).As a result, we demonstrated that the internalization of infective virus triggered the phosphorylation ofERK1/2, which was involved in the activation of caspase-9, the intrinsic pathway of apoptosis and thedelivery of viral peptides on MHC class I molecules. While, inactivated virus (iFMDV) did not affect thispathway or any function mediated by its activation. As described, infectious virus in DCs was also asso-ciated to autophagy LC3 protein and was associated to lysosomal protein Lamp-2; contrary to observefor the iFMDV. Strikingly, the processing of viral antigens to accommodate in class I molecules doesnot appear to involve the proteasome. Finally, this increased presentation promotes a specific cytotoxicresponse against infectious virus. Fil: Langellotti, Cecilia Ana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Cesar, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina Fil: Soria, Ivana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Quattrocchi, Valeria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Jancic, Carolina Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina Fil: Zamorano, Patricia Ines. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Vermeulen, Elba Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina

Dendritic cells (DC) are antigen presenting cells (APC) uniquely capable of priming naïve T cells and cross-presenting antigens and determine the type of immune response elicited against an antigen. TAT peptide (TATp), is an amphipathic, arginine-rich, cationic peptide that promotes penetration and translocation of various molecules and nanoparticles into cells. TATp-liposomes (TATp-L) used for DC transfection were prepared using TATp derivatized with a lipid-terminated polymer capable of anchoring in the liposomal membrane. Here, we show that the addition of TATp to DNA-loaded liposomes increased the uptake of DNA in DC. DNA-loaded TATp-L increased the in vitro transfection efficiency in DC cultures as evidenced by an enhanced expression of the enhanced green fluorescent protein (EGFP) and bovine herpes virus type 1 (BoHV-1) glycoprotein D (gD). The de novo synthesized gD protein was immunologically stimulating when transfections were performed with TATp-L as indicated by the secretion of interleukin 6 (IL-6). Fil: Pappalardo, Juan Sebastian. Northeastern University. Center for Pharmaceutical Biotechnology and Nanomedicine; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Langellotti, Cecilia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Di Giacomo, Sebastián. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Olivera, Valeria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Quattrocchi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Zamorano, Patricia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina Fil: Hartner, William C.. Northeastern University. Center for Pharmaceutical Biotechnology and Nanomedicine; Estados Unidos Fil: Levchenko, Tatyana S.. Northeastern University. Center for Pharmaceutical Biotechnology and Nanomedicine; Estados Unidos Fil: Torchilin, Vladimir P.. Northeastern University. Center for Pharmaceutical Biotechnology and Nanomedicine; Estados Unidos

A live system to release heterologous antigens using an attenuated Salmonella strain was developed. We transformed Salmonella typhimurium LVR03 (S. LVR03) with a recombinant pTECH2 vector encoding 0, 1, 2, and 4 tandem copies of an imunogenic peptide of bovine herpes virus-1 (BoHV-1) glycoprotein D (gD). The system used yielded peptides fused to the non-toxic C fragment of the tetanus toxin (TetC), which has been shown to have adjuvant properties. Inoculation of BALB/c mice with the transformed Salmonella strains gave rise to a mild self-limited infection, with primary replication of bacteria occurring in Peyer's patches, even when the bacteria was administered intranasally. Humoral and cellular immune responses directed against the BoHV-1 antigens were evaluated after oral or intranasal administration of the recombinant bacteria. The results showed that the S. LVR03-dimer vaccine induced specific humoral (IgG in serum and IgG(1) and IgA in saliva), and cellular immune responses (lymphoproliferation and lymphokine secretion), against not only the selected peptide and whole gD, but also against BoHV-1, when administered intranasally. This is the first time Salmonella has been used as an expression vector to induce immunity against BoHV-1. This work demonstrates the feasibility of using this antigen-release system and encourages future experimentation with a bovine experimental model.

Foot and Mouth Disease (FMD) is an acute disease of cloven-hoofed species. We studied the protection and early immune response induced in the murine model by vaccines formulated with inactivated virus and two different adjuvants. The presence of IMS12802PR or ISA206VG adjuvants yielded protection against viral challenge at early times post vaccination and induced FMDV-specific, but non neutralizing, antibody titers. In vivo macrophage depletion in vaccinated mice severely decreased the protection levels after virus challenge, indicating a central role of this cell population in the response elicited by the vaccines. Accordingly, opsonophagocytosis of FITC-labelled virus was augmented in 802-FMDVi and 206-FMDVi vaccinated mice. These results demonstrate the ability of the studied adjuvants to enhance the protective responses of these inactivated vaccines without the increase in seroneutralizing antibodies and the main role of opsonization and phagocytosis in the early protective immune responses against FMD infection in the murine model.

It is well documented that adjuvants improve the immune response generated by traditional viral vaccines; however, less is known about their effects on the immune response elicited by DNA vaccines. In this study, we have investigated the use of adjuvants, and have analyzed the humoral and cellular specific immune responses elicited by DNA vaccines based on the BoHV-1 glycoprotein D (secreted version) in pCIneo vector with and without Montanide ISA25 (O/W), ISA206 VG (SEPPIC) and Cliptox™ (natural microparticles of clinoptilolite). The comparison of the immune response induced in mice by pCIgD formulated with or without adjuvants showed that the immunomodulators affect the total specific humoral and cellular response. The isotypes induced by these adjuvants were of the type Th1/Th2. A significant increase in the mac-3+ and F4/80+ populations of the groups receiving pCIneo with ISA25, ISA206; and an increase in CD4+ populations of the group receiving pCIneo ISA25, in comparison with the pCIneo group was observed. On the other hand, mice vaccinated with pCIgD/ISA25, pCIgD/ISA206, or pCIgD/Cliptox developed a significantly higher specific cytotoxic activity against BoHV-1 than the pCIgD and pCIneo groups. In this report we propose the use of ISA25, ISA206 or Cliptox as adjuvants in a DNA vaccine since they are able to induce not only a specific humoral immune response but also a specific cellular immune response.

Histamine controls the function of dendritic cells (DCs). It appears to be required for the normal development of DCs. It also induces the chemotaxis of immature DCs and promotes the differentiation of CD4(+) T cells into cells with a T helper type 2 (Th2) profile. Moreover, we have recently shown that histamine stimulates both the uptake and the cross-presentation of antigens by DCs, supporting the theory that histamine promotes activation of CD8(+) T cells during the development of allergic pathologies. Here, we investigated whether the course of an allergic response, in a well-defined model of ovalbumin (OVA)-induced allergic airway inflammation, could be modulated by intratracheal injection of OVA-pulsed DCs previously treated with histamine (DCHISs). Compared with control DCs, DCHISs induced: (i) greater recruitment of CD8(+) T cells in the lung, (ii) greater stimulation of the production of interleukin (IL)-5 by lung CD8(+) T cells, and (iii) increased recruitment of CD11c/CD8 double-positive DCs in the lungs of allergic mice. Moreover, mice treated with DCHISs showed increased levels of serum-specific immunoglobulin E (IgE) antibodies directed to OVA, and a higher proportion of eosinophils in bronchoalveolar lavage (BAL) compared with mice treated with OVA-pulsed control DCs. Our results support the notion that histamine, by acting on DCs, increases the severity of allergic processes.

Antigen presenting cells (APC) are among the most important cells of the immune system since they link the innate and the adaptative immune responses, directing the type of immune response to be elicited. To modulate the immune response in immune preventing or treating therapies, gene delivery into immunocompetent cells could be used. However, APC are very resistant to transfection. To increase the efficiency of APC transfection, we have used liposome-based lipoplexes additionally modified with cell-penetrating TAT peptide (TATp) for better intracellular delivery of a model plasmid encoding for the enhanced-green fluorescent protein (pEGFP). pEGFP-bearing lipoplexes made of a mixture of PC:Chol:DOTAP (60:30:10 molar ratio) with the addition of 2% mol of polyethylene glycol-phosphatidylethanolamine (PEG-PE) conjugate (plain-L) or TATp-PEG-PE (TATp-L) were shown to effectively protect the incorporated DNA from degradation. Uptake assays of rhodamine-labeled lipoplexes and transfections with the EGFP reporter gene were performed with APC derived from the mouse spleen. TATp-L-based lipoplexes allowed for significantly enhanced both, the uptake and transfection in APC. Such a tool could be used for the APC transfection as a first step in immune therapy.

Maria Marta Amaral1*, Carolina A Alvarez1*, Cecilia Langellotti2, Carolina Jancic1, Gabriela Salamone1, Jorge Geffner1, Mónica Vermeulen1,1Institute of Hematologic Research, National Academy of Medicine, Buenos Aires, Argentina; 2Institute of Virology, CICVyA, INTA, Castelar, Argentina *Authors contributed equally to this workBackground: Histamine is an important mediator in the development of allergic reactions. The biological effects of histamine are mediated through four histaminergic receptors. In recent years, an important role has been assigned to the proinflammatory functions of histamine regarding the H4 receptor. Previously, we have demonstrated that injection of immature dendritic cells treated with histamine into allergic mice promotes an increase in CD8+ Tc2 lymphocytes, which are involved in the worsening of allergy symptoms during the chronic phase of the disease. The aim of this study was to evaluate the role of the H3/H4 receptor antagonist, thioperamide, in allergy.Methods: Ovalbumin-allergized mice and nonallergized mice were injected with phosphate-buffered saline, dendritic cells, or thioperamide-treated dendritic cells. After treatment, the lungs of the mice were obtained and analyzed for changes in the populations of dendritic cells and T lymphocytes, as well as the expression of H and H4 receptors in mononuclear lung cells.Results: We found an increase in regulatory T cells in the lungs of allergic mice intratracheally injected with dendritic cells which had their H3/H4 receptors blocked with thioperamide. We also found an increase in the production of interleukin-10 by dendritic cells of the lung. Finally, we observed a decrease in serum levels of specific anti-IgE and a reduction of eosinophils in bronchoalveolar lavage from allergic mice.Conclusion: Thioperamide induces a significant improvement in symptoms of allergic reaction perhaps via induction of regulatory T lymphocytes. These findings may become relevant in the understanding of type 1 hypersensivity reactions.Keywords: dendritic cells, regulatory T lymphocytes, thioperamide, histamine, allergy

Synthetic peptides mimicking protective B- and T-cell epitopes are good candidates for safer, more effective FMD vaccines. Nevertheless, previous studies of immunization with linear peptides showed that they failed to induce solid protection in cattle. Dendrimeric peptides displaying two or four copies of a peptide corresponding to the B-cell epitope VP1 [136–154] of type O FMDV (O/UKG/11/2001) linked through thioether bonds to a single copy of the T-cell epitope 3A [21–35] (termed BT and BT, resp.) afforded protection in vaccinated pigs. In this work, we show that dendrimeric peptides BT and BT can elicit specific humoral responses in cattle and confer partial protection against the challenge with a heterologous type O virus (O1/Campos/Bra/58). This protective response correlated with the induction of specific T-cells as well as with an anamnestic antibody response upon virus challenge, as shown by the detection of virus-specific antibody-secreting cells (ASC) in lymphoid tissues distal from the inoculation point., National Institute of Agricultural Technology (Grant no. PNSA 1115052) and an INTA-INIA (Spain) cooperation agreement. Work at UPF and CBMSO was supported by MINECO, Spain (Grant no. AGL2014-52395-C2)