Adjuvant Effect of the Propionibacterium acnes and Its Purified Soluble Polysaccharide on the Immunization with Plasmidial DNA Containing a Trypanosoma cruzi Gene

Abstract

In the present work we investigated the role of killed Propionibacterium acnes or a soluble polysaccharide extracted from bacterium cell wall in modulated experimental immunization with plasmidial DNA. We used a plasmid, p154/13, containing a gene‐encoding catalytic domain of Trypanosoma cruzi (T. cruzi) trans‐sialidase. As previously described, immunization of BALB/c mice with p154/13 elicited humoral, cell‐mediated and protective immune responses against T. cruzi infection. In this study we describe that both P. acnes and its soluble polysaccharide fraction have the ability to modulate the immune response elicited by p154/13. Treatment with these adjuvants enhanced specific trans‐sialidase Th1 immune response, as revealed by a lower IgG1/IgG2a ratio and stronger in vitro IFN‐γ synthesis by CD4+ T cells. The most important fact was that treatment with P. acnes or its soluble polysaccharide fraction in the presence of p154/13 significantly reduced the peak of parasitemia observed 7 to 8 days after T. cruzi challenge. These data suggest that P. acnes or its soluble polysaccharide fraction may improve the protective potential of a DNA vaccine against experimental T. cruzi infection.

Specific Humoral Immune Response Induced by Propionibacterium acnes Can Prevent Actinobacillus pleuropneumoniae Infection in Mice

“…Moreover, P. acnes is rarely identified as a cause of significant infection (11). In the present study, P. acnes induced biological effects that modulate the innate and acquired immune responses, causing increased phagocytic and tumoricidal activities in macrophages (12)(13)(14), increased antibody responses (15,16), and increased resistance to different pathogens (15,17). Therefore, the use of P. acnes and its components as immune enhancers and antineoplastic agents has become a focus in clinical and basic research.…”

Modulation of the type I hypersensitivity late phase reaction to OVA by Propionibacterium acnes-soluble polysaccharide

“…This polysaccharide, similarly to the whole bacterium, increased nitric oxide (NO) and TNF-␣ synthesis, enhanced phagocytic activity by peritoneal macrophages and promoted resistance to infection [38]. We also observed that PS was a major P. acnes component responsible for bacterium adjuvant effect to antibody response and IFN-␥ production on a Trypanosoma cruzi DNA vaccine [24]. Besides, P. acnes and PS were able to modulate the number of different peritoneal cell populations and their functions, including macrophage tumoricidal activity [22].…”

“…In our laboratory, we purified a soluble polysaccharide phenol-extracted from P. acnes cell wall which induces similar effects to the whole bacterium [22,24,38,39]. However, the fine structural characterization of this compound had not yet been performed.…”

“…P. acnes-soluble polysaccharide extraction P. acnes-soluble polysaccharide was obtained as described [22,24,39]. Briefly, to 30 mL of heat-killed bacteria suspension (1 mg/mL), 30 mL of 90% phenol were added and the suspension was incubated for 10 min in a water bath at 70 • C, based on the Palmer and Gerlough protocol for polysaccharide extraction [42].…”

“…LPR underlies the pathogenesis of allergic asthma, in which the airway eosinophilia, the increased mucus production and structural remodeling lead to airway obstruction and bronchial hyperresponsiveness to inhaled allergen [3,4]. This reaction is mediated by specific immuneglobulin isotypes, such as IgE (humans and mice) and IgG1 (mice), induced by as adjuvant for antibody response [23,24] and enhances resistance to infections [25][26][27][28][29][30]. The mechanisms implicated in these effects are related to a Th1 response, with increased production of IL-12, IL-18, IFN-␥, IL-1␣, IL-6 and TNF-␣ [31][32][33][34][35] and reduction of IL-4-producing CD4 + NKT cells [34].…”