Development of an indirect ELISA for serological diagnosis of bovine herpesvirus 5

Bovine herpesviruses 1 and 5 (BoHV-1 and BoHV-5) are economically important pathogens, associated with a variety of clinical syndromes, including respiratory and genital disease, reproductive failure and meningoencephalitis. The standard serological assay to diagnose BoHV-1 and BoHV-5 infections is the virus neutralization test (VNT), a time consuming procedure that requires manipulation of infectious virus. In the present study a highly sensitive and specific single dilution indirect ELISA was developed using recombinant glycoprotein D from BoHV-5 as antigen (rgD5ELISA). Bovine serum samples (n = 450) were screened by VNT against BoHV-5a and by rgD5ELISA. Compared with the VNT, the rgD5ELISA demonstrated accuracy of 99.8%, with 100% sensitivity, 96.7% specificity and coefficient of agreement between the tests of 0.954. The rgD5ELISA described here shows excellent agreement with the VNT and is shown to be a simple, convenient, specific and highly sensitive virus-free assay for detection of serum antibodies to BoHV-5

Induced humoral immune responses in bovines to recombinant glycoprotein D of bovine herpesvirus type 5

Glycoprotein D (gD) is essential for attachment and penetration of bovine herpesvirus type 5 (BoHV-5) into susceptible cells, and is a major target of host immune systems, inducing strong humoral and cellular immune responses. The immunogenicity of recombinant BoHV-5 (rgD5) expressed in Pichia pastoris was evaluated in bovines. Vaccines formulated with 100 μg rgD5 dose and adjuvants (Montanide ISA50V2 or Aluminum Hydroxide) with or without inactivated BoHV-5 or rgD5 without adjuvants were administered intramuscularly. A commercial vaccine was also used as control. The vaccine formulation rgD5 + ISA50V2 stimulated humoral immune responses after two doses, and higher titer of neutralizing antibodies were obtained in all three oil-based adjuvants formulations when compared to Hydroxide Aluminium adjuvant or the commercial vaccine. The vaccine BoHV-5 + rgD5 + ISA50V2 stimulated titers of neutralizing antibodies approximately 8 log2, which demonstrated higher correlations on the Indirect ELISA. Together, the results suggest that the recombinant gD5 conserved neutralizing epitopes and was able to stimulate a efficient humoral immune response in bovines.A glicoproteína D (gD) é essencial para ligação e penetração de herpesvírus bovino 5 (BoHV-5) em células suscetíveis, e é um alvo importante do sistema imune do hospedeiro, induzindo respostas imunes humoral e celular. A imunogenicidade da glicoproteína D recombinante de BoHV-5 (rgD5) expressa em Pichia pastoris foi avaliada em bovinos. Vacinas formuladas com 100 μg de rgD5 por dose e adjuvante a base de óleo (Montanide ISA50V2) ou hidróxido de alumínio, com ou sem adição de BoHV-5 inativado foram administradas via intramuscular, e uma vacina comercial utilizada como controle. A vacina rgD5 + ISA50V2 estimulou resposta imune humoral após duas doses, e os mais elevados títulos de anticorpos neutralizantes foram obtidos em todas as três formulações de adjuvantes à base de óleo quando comparado com a formulação de vacinas de adjuvante de hidróxido de alumínio e vacina comercial. A vacina BoHV-5 + rgD5 + ISA50V2 estimulou títulos de anticorpos neutralizantes aproximadamente a 8 log2, demonstrando correlação significativa com o ELISA indireto. Em conjunto, os resultados sugerem que a rgD5 conservou epítopos neutralizantes e foi capaz de estimular uma resposta imune humoral eficiente em bovinos

Human thymopoiesis is influenced by a common genetic variant within the TCRA-TCRD locus

International audienceThe thymus is the primary lymphoid organ where naïve T cells are generated; however, with the exception of age, the parameters that govern its function in healthy humans remain unknown. We characterized the variability of thymic function among 1000 age- and sex-stratified healthy adults of the Milieu Intérieur cohort, using quantification of T cell receptor excision circles (TRECs) in peripheral blood T cells as a surrogate marker of thymopoiesis. Age and sex were the only nonheritable factors identified that affect thymic function. TREC amounts decreased with age and were higher in women compared to men. In addition, a genome-wide association study revealed a common variant (rs2204985) within the T cell receptor TCRA-TCRD locus, between the DD2 and DD3 gene segments, which associated with TREC amounts. Strikingly, transplantation of human hematopoietic stem cells with the rs2204985 GG genotype into immunodeficient mice led to thymopoiesis with higher TRECs, increased thymocyte counts, and a higher TCR repertoire diversity. Our population immunology approach revealed a genetic locus that influences thymopoiesis in healthy adults, with potentially broad implications in precision medicine