title: Tissue distribution of DNA-Hsp65/TDM-loaded PLGA microspheres and uptake by phagocytic cells.
abstract: This study aimed to demonstrate that microspheres, used as delivery vehicle of DNA-Hsp65/TDM [plasmid DNA encoding heat shock protein 65 (Hsp65) coencapsulated with trehalose dimycolate (TDM) into PLGA microspheres], are widely spread among several organs after intramuscular administration in BALB/c mice. In general, we showed that these particles were phagocytosed by antigen presenting cells, such as macrophages and dendritic cells. Besides, it was demonstrated herein that draining lymph node cells presented a significant increase in the number of cells expressing costimulatory molecules (CD80 and CD86) and MHC class II, and also that the administration of the DNA-Hsp65/TDM and vector/TDM formulations resulted in the up-regulation of CD80, CD86 and MHC class II expression when compared to control formulations (vector/TDM and empty). Regarding the intracellular trafficking we observed that following phagocytosis, the microspheres were not found in the late endosomes and/or lysosomes, until 15 days after internalization, and we suggest that these constructions were hydrolysed in early compartments. Overall, these data expand our knowledge on PLGA [poly (lactic-co-glycolic acid)] microspheres as gene carriers in vaccination strategies, as well as open perspectives for their potential use in clinical practice.
authors: Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av, Bandeirantes, 3900, 14049-900, Ribeirão Preto, SP, Brasil. tromboneapf@usp.br
authors: Ana Paula F
authors: AP
authors: Trombone
authors: Celio L
authors: CL
authors: Silva
authors: Luciana P
authors: LP
authors: Almeida
authors: Rogerio S
authors: RS
authors: Rosada
authors: Karla M
authors: KM
authors: Lima
authors: Constance
authors: C
authors: Oliver
authors: Maria C
authors: MC
authors: Jamur
authors: Arlete A M
authors: AA
authors: Coelho-Castelo