Open AccessKilled Propionibacterium acnes enhances immunogenicity and tumor growth control of a dendritic-tumor cell hybrid vaccine in a murine melanoma model
Author(s) -
Mayari Eika Ishimura,
Daniela Teixeira,
Gabriela da Paz Silveira,
Mônica Gambero,
Gabriel A. C. Gama,
Bruna Sanches Ozane Pimenta,
Elaine G. Rodrigues,
Ieda Maria Longo-Maugéri
Publication year - 2018
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0205148
Subject(s) - immunogenicity , immune system , propionibacterium acnes , adjuvant , antigen , immunology , biology , dendritic cell , immunotherapy , cytotoxic t cell , microbiology and biotechnology , in vitro , genetics , bacteria , biochemistry
Hybrid vaccines have been investigated in clinical and experimental studies once expresses total antigens of a tumor cell combined with the ability of a dendritic cell (DC) to stimulate immune responses. However, the response triggered by these vaccines is often weak, requiring the use of adjuvants to increase vaccine immunogenicity. Killed Propionibacterium acnes ( P . acnes ) exerts immunomodulatory effects by increasing the phagocytic and tumoricidal activities of macrophages, promoting DC maturation, inducing pro-inflammatory cytokines production and increasing the humoral response to different antigens. Here, we evaluated the effect of P . acnes on a specific antitumor immune response elicited by a hybrid vaccine in a mouse melanoma model. Hybrid vaccine associated with P . acnes increased the absolute number of memory T cells, the IFN-γ secretion by these cells and the IgG-specific titers to B16F10 antigens, polarizing the immune response to a T helper 1 pattern. Furthermore, the addition of P . acnes to a hybrid vaccine increased the cytotoxic activity of splenocytes toward B16F10 in vitro and avoided late tumor progression in a pulmonary colonization model. These results revealed the adjuvant effect of a killed P . acnes suspension, as it improved specific humoral and cellular immune responses elicited by DC-tumor cell hybrid vaccines.