Fusion of foreign T‐cell epitopes and addition of TLR agonists enhance immunity against Neospora caninum profilin in cattle

Abstract

We demonstrated recently that immunization with recombinant Neospora caninum profilin (rNcPRO) induces limited protection and a regulatory T-cell response in mice. The aim of this study was to evaluate the immune response elicited by rNcPRO in cattle and assess a strategy to enhance its immunogenicity, combining the addition of T-cell epitopes and immune modulators. We developed a chimeric recombinant profilin fused to functional T-cell epitopes present in the N-terminal sequence of vesicular stomatitis virus (VSV) glycoprotein G (rNcPRO/G). Groups of three cattle were immunized with two doses (2 weeks apart) of rNcPRO or rNcPRO/G formulated with alum hydroxide or a nanoparticulated soya-based adjuvant enriched with Toll-like receptor (TLR) 2 and TLR9 agonists, aimed to tackle the MyD88 pathway (AVECplus). rNcPRO induced only a primary immune response (IgM mediated), while antibodies in rNcPRO/G-vaccinated animals switched to IgG1 after the booster. The vaccine formulated with rNcPRO/G and AVECplus improved the production of systemic IFN-γ and induced long-term recall B-cell responses. Overall, our study provides data supporting the use of T-cell epitopes from VSV glycoprotein G and TLR agonists to enhance and modulate immunity to peptide antigens in bovines, particularly when using small proteins from parasites for which immune responses are usually feeble.

Analyzing the exome heterogeneity of cattle immunity genes with the method of flow-cell sequencing

“…In addition, TLRs play an important role in maintaining tissue haemostasis, for example, in healing of damaged tissues. TLR-1, TLR-2, TLR4, TLR-6 and TLR-10 are involved in lipid recognition, TLR-5 and TLR-11 recognize proteins, and TLR-3, TLR-7, TLR-8 and TLR-9 recognize nucleic acids [1,3].…”

“…Toll-like family (TLR) are essential in the formation of the innate immune response of animals to various pathogens, for example fungal, bacterial and viral origin [1]. The variability of immunity genes with highthroughput technology has been studied and shown to be a modern and real, and cattle immunity genes in part in genes TLR-1-10 that recognize viral nucleic acids, microorganisms and other biological molecules (polysaccharides, proteins) [2,3].…”

Secretory Nanoparticles of Neospora caninum Profilin-Fused with the Transmembrane Domain of GP64 from Silkworm Hemolymph

“…Profilin of N. caninum (NcPROF) is recognized and conserved as a vaccine candidate with high potential against neospora infections [10]. Interestingly, profilin is known as a small actin-binding protein located at the apical end of N. caninum tachyzoites and is essential for invasion of the host cell by regulating the polymerization and depolymerization of actin filaments [11]. Furthermore, Jenkins et al [12] and Mansilla et al [13] revealed that T. gondii profilin binds to Toll-like receptor 11 (TLR11) in mice and is responsible for activating dendritic cells and stimulating the release of cytokines such as interleukin 12 (IL-12) and IFN-γ.…”

Papel de fatores celulares indutores de resposta imune de padrão Th1 na produção e funções de anticorpos contra Neospora caninum

“…Na resposta imune contra N. caninum em camundongos, TLRs tem um papel importantíssimo no reconhecimento de proteínas de superfície. Foi demonstrado que em murinos, TLR11 reconhece as profilinas, que se localizam na região apical de N. caninum, sendo essenciais para sua invasão e indução da resposta pró-inflamatória do tipo 1 (JENKINS et al, 2010;MANSILLA et al, 2016a). Já foi demonstrado que, TLR2 presente na superfície de macrófagos, está associado a molécula adaptadora MyD88, que se liga a esse receptor induzindo o fator de transcrição NF -k a secretar IL-12 (MINEO et al, 2010).…”

“…Na ausência dessas citocinas, a produção de Esse grupo demonstrou ainda um taxa muito pequena de fagocitose pelos macrófagos mostrando que os anticorpos induzidos na ausência de MyD88 não foram capazes de opsonizar os parasitos de forma eficiente. Trabalhos que desenvolveram modelos de vacinas que exacerbam a via dependente MyD88 induzida por receptores como, TLR2 e TLR9, tiveram resultados de proteção eficaz em bovinos, confimando a importância dessa molécula na indução da produção de anticorpos (MANSILLA et al, 2016a;MANSILLA et al, 2016b).…”