Minthostachys verticillata essential oil microcapsule as possible candidate for vaccine adjuvant

CAMPRA NA; MONTIRONI ID; MOLIVA MV; ARSAUTE S; RAVIOLO JM; CAMACHO NM; PAREDES A; MALETTO BA; PALMA S; REINOSO EB; CARIDDI L

Tucumán

Congreso; LXVII Reunión Anual de la Sociedad Argentina de Inmunología; 2019

Sociedad Argentina de Inmunología

In a previous study we demonstrated that Minthostachys verticillata essential oil (2.5 mg/ml) has adjuvant effect using OVA as antigen. The aim of this study was to determine the effect of EO microcapsule (EOMC) against humoral and cellular immune response using Enterococcus faecium as antigen. Balb/c mice (n=4 per group) were immunized by subcutaneous injection (day 0) and revaccinated (day 14 and 28) as follows: Group 1:100 μl saline solution; Group 2:100 μl E. faecium bacterin 6x109 CFU/ml; Group 3: 100 μl bacterin + Incomplete Freund's Adjuvant 50%; Group 4: 100 μl bacterin +EO (2,5 mg/ml); Group 5: 100 μl bacterin + microcapsule wall material (2,5 mg/ml); Group 6: 100 μl bacterin + EOMC (5 mg/ml). Seven days after last revaccination, serum samples were collected and analyzed for antigen-specific total antibodies (IgG, IgM and IgA) by indirect ELISA. In addition, splenic lymphocytes were obtained for XTT proliferation assay and quantification of CD4+ and CD8+ T cells by flow cytometer. Any mouse died; however only in group 3 a significant induration at the injection site was observed. EOMC induced the highest antibodies levels (p