Importantly, adoptive transfer of antigen-loaded DCs stimulated with GLA-SE in vivo was sufficient to induce specific Th1-cell responses in naïve mice. In contrast, DCs stimulated with emulsion alone were unable to prime T cells. Since the DCs also had to express MHCII, this indicates that their T-cell immunizing function required direct presentation of antigen in the mice primed by adoptively transferred DCs. To our surprise, Selleckchem Sirolimus antibody responses were unaltered after CD11c+

depletion. In this paper, we only analyzed total IgG responses. Maturation of DCs may still have a role in antibody affinity. The type of immune response that eliminates an infection depends on the type of pathogen. Induction of CD4+ T-cell responses by vaccination was learn more associated with diminished simian immunodeficiency virus (siv) replication after intrarectal challenge and decreased HIV acquisition

in the Thai HIV vaccine trial 44, 45. The results presented here demonstrate that GLA-SE is an efficient adjuvant for the generation of HIV-gag-specific Th1-cell immune response. IFN-γ was produced in large amounts by antigen-specific T cells in both spleen and lymph nodes. HIV-1 vaccines will most likely need to induce mucosal immunity. Mucosal tissues are the major site of natural HIV transmission and the reservoir for HIV replication quickly leading to a rapid loss of T cells in the intestine 46, 47. In addition, Th1 type CD4+ T cells are known to improve the mobilization of the cognate antigen-specific CD8+ T cells to a site of infectious challenge 48, 49. Thus GLA-SE has the capacity to adjuvant a protein vaccine to

induce mucosal immunity that potentially is valuable to limit viral replication and curtail systemic dissemination. Previous studies successfully showed that local immune responses were able to prevent virus spread from the gut mucosa into the systemic circulation 50–52. However, the general belief is that local but not systemic immunization is required to induce robust mucosal responses 53–55. Interestingly, we Interleukin-2 receptor found that s.c. injection of the GLA-SE and anti-DEC-HIV gag p24 vaccine was able to induce strong mucosal T-cell responses. Immunization with HIV-gag targeted or untargeted protein plus GLA-SE induced a broad range of different antibody isotypes and therefore a combination of Th1 and Th2-cell responses. This contrast, i.e. with polarized Th1 T-cell responses, may be explained by the different requirement for DC priming. This result is consistent with previous studies where addition of GLA-SE gives a mixed Th1/Th2-cell response but also increases the IgG2/IgG1 ratio to an existent M. Tuberculosis and Influenza vaccine 27, 56.