Sistema FMUSP-HC: Faculdade de Medicina da Universidade de São Paulo (FMUSP) e Hospital das Clínicas da FMUSPTEIXEIRA, Franciane Mouradian EmidioOLIVEIRA, Luana de MendoncaPIETROBON, Anna JuliaSALLES, Erika Machado deLIMA, Maria Regina D'ImperioVIANA, Isabelle Freire TabosaLINS, Roberto DiasRIGATO, Paula OrdonhezMARQUES, Ernesto Torres de AzevedoDUARTE, Alberto Jose da SilvaSATO, Maria Notomi2022-10-262022-10-262022VACCINES, v.10, n.8, article ID 1246, 14p, 2022https://observatorio.fm.usp.br/handle/OPI/49357Neonates have a limited adaptive response of plasma cells, germinal center (GC) B cells, and T follicular helper cells (T-FH). As neonatal vaccination can be an important tool for AIDS prevention, these limitations need to be overcome. Chimeric DNA vaccine encoding p55Gag HIV-1 protein conjugated with lysosomal-associated membrane protein 1 (LAMP-1) has been described as immunogenic in the neonate period. Herein, we investigated the immunologic mechanisms involved in neonatal immunization with a LAMP-1/p55Gag (LAMP/Gag) DNA vaccine in a C57BL/6 mouse background. Neonatal LAMP/Gag vaccination induced strong Gag-specific T-cell response until adulthood and elevated levels of anti-Gag IgG antibodies. We also demonstrated for the first time that the immunogenicity of the neonatal period with LAMP/Gag is due to the induction of high-affinity anti-p24 IgG antibodies and long-term plasma cells. Together with that, there is the generation of early TFH cells and the formation of GC sites with the upregulation of activation-induced cytidine deaminase (AID) enzyme mRNA and protein expression in draining lymph nodes after neonatal LAMP/Gag vaccination. These findings underscore that the LAMP-1 strategy in the chimeric vaccine could be useful to enhance antibody production even in the face of neonatal immaturity, and they contribute to the development of new vaccine approaches for other emerging pathogens at an early stage of life.engopenAccessDNA vaccineneonateHIVimmunogenicitygerminal centert-cell responsesmembrane-proteindouble-blindmediated-immunityii compartmenthelper-cellsvaccinegagdnaefficacyarticleCopyright MDPI10.3390/vaccines10081246ImmunologyMedicine, Research & Experimental2076-393X