1,721,003 research outputs found
Expression of immunomodulating molecules on the surface of the vaccine vector Streptococcus gordonii
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Peptide-specific T helper cells identified by MHC class II tetramers differentiate into several subtypes upon immunization with CAF01 adjuvanted H56 tuberculosis vaccine formulation
No full textCD4(+) T-cell priming is an essential step in vaccination due to the key role of T helper cells in driving both effector and memory immune responses. Here we have characterized in C57BL/6 mice the T helper subtype differentiation among tetramer-specific CD4(+) T cells primed by subcutaneous immunization with the tuberculosis vaccine antigen H56 plus the adjuvant CAF01. Peptide-specific population identified by the MHC class II tetramers differentiated into several T helper subtypes upon antigen encounter, and the frequency of subpopulations differed according to their localization. Th1 (CXCR3(+)T-bet(+)), Tfh (CXCR5(+)PD-1(+)Bcl-6(+)) and RORγt(+) cells were induced in the lymph nodes draining the immunization site (dLN), while Th1 cells were the predominant subtype in the spleen. In addition, CD4(+) T cells co-expressing multiple T-cell lineage-specifying transcription factors were also detected. In the lungs, most of the tetramer-binding T cells were RORγt(+), while Tfh and Th1 cells were absent. After boosting, a higher frequency of tetramer-binding cells co-expressing the markers CD44 and CD127 was detected compared to primed cells, and cells showed a prevalent Th1 phenotype in both dLN and spleens, while Tfh cells were significantly reduced. In conclusion, these data demonstrate that parenteral immunization with H56 and CAF01 elicits a distribution of antigen-specific CD4(+) T cells in both lymphoid tissues and lungs, and gives rise to multiple T helper subtypes, that differ depending on localization and following reactivation
Short or Long Interval between Priming and Boosting: Does It Impact on the Vaccine Immunogenicity?
Full text linkCharacterizing the impact of the vaccination schedule on the induction of B and T cell immune responses is critical for improving vaccine immunogenicity. Here we compare the effect of a short (4 weeks) or a long (18 weeks) interval between priming and boosting in mice, using a model vaccine formulation based on the chimeric tuberculosis vaccine antigen H56 combined with alum. While no significant difference was observed in serum antigen-specific IgG response and the induction of antigen-specific T follicular helper cells into draining lymph nodes after the two immunization schedules, a longer interval between priming and boosting elicited a higher number of germinal center-B cells and H56-specific antibody-secreting cells and modulated the effector function of reactivated CD4+ T cells. These data show that the scheduling of the booster immunization could affect the immune response elicited by vaccination modulating and improving the immunogenicity of the vaccine. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Recombinant gram-positive bacteria for intranasal immunization: characterization of the murine nasal-associated lymphoid tissue and study of local T-cell priming
No full textAntibody response and protection from challenge in mice immunized with recombinant Streptococcus gordonii expressing fragment C of tetanus toxin
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Primary activation of CD4+ and CD8+ T cells following mucosal vaccination with recombinant bacteria
No full textCTA1-DD has an Adjuvant Effect Once Expressed on the Surface of the Gram-Positive Bacterium Streptococcus gordonii
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