Elsevier

Vaccine

Volume 30, Issue 6, 1 February 2012, Pages 1115-1123
Vaccine

Corynebacterium pyruviciproducens promotes the production of ovalbumin specific antibody via stimulating dendritic cell differentiation and up-regulating Th2 biased immune response

https://doi.org/10.1016/j.vaccine.2011.12.005Get rights and content

Abstract

Corynebacterium pyruviciproducens (C. pyruviciproducens), a newly discovered Corynebacterium, is gram-positive, non-flagellate, non-spore-forming lipophilic rod. No known pathogenic components of Corynebacteria have been found in this new bacterium, such as diphtheria toxin and tuberculostearic acid. In the present study, referring to Propionibacterium acnes (P. acnes), a well-known bacterial adjuvant, the stimulation of dendritic cells by C. pyruviciproducens was analyzed through detecting the levels of cytokine-secretion, ability of cell-proliferation and expression of membrane molecules. In addition, the effect of C. pyruviciproducens in promoting antibody production in vivo was detected. Compared with P. acnes, C. pyruviciproducens more strongly enhanced cytokine secretion including inflammatory factor IL-6 and Th1-associated molecule IL-12, and more effectively induced proliferation, activation or maturation of D2SC/1 (a murine dendritic cell line) and bone marrow-derived dendritic cells (BMDC). Vaccination studies in mice using ovalbumin (OVA) as a model antigen showed that C. pyruviciproducens effectively promoted antigen-specific humoral immune response by increasing OVA-specific antibody, Th2-biased response in spleen and high IL-4/IFN-γ ratio in serum.

Highlights

C. pyruviciproducens effectively induced proliferation, activation of dendritic cells. ► C. pyruviciproducens promoted antigen-specific humoral immune response. ► C. pyruviciproducens may be used as a bacterial adjuvant.

Introduction

In recent years, a growing number of researchers are showing interest in bacterial adjuvants and many bacterial components are being developed to circumvent unsafe effects [1]. Propionibacterium acnes is a typical bacterial immunomodulator and has been used to treat several kinds of cancers [2], [3], [4]. Lately, some active components isolated from P. acnes are developed as a new immunomodulator [5].

Corynebacterium pyruviciproducens is a newly discovered Corynebacterium species without known pathogenic components such as diphtheria toxin and tuberculostearic acid [6] that has similar biological properties to P. acnes. Meanwhile, C. pyruviciproducens showed a strong ability to induce antibody production in our previous experiments, and it aroused our interest in the immunoregulation of C. pyruviciproducens compared with P. acnes.

Dendritic cells (DCs) play a crucial role in connecting inherent immunity with adaptive immunity and are key players in activation of the adaptive immune system owing to their antigen presentation ability and priming of T cells [7]. DCs also express co-stimulation molecules and secrete several cytokines which efficiently activate T and B lymphocytes. Numerous studies have validated that DCs, capable of modulating both cellular and humoral immune responses, can be considered as effective regulator for studying bacteria-based immunostimulatory effects.

In this study, D2SC/1 cell line and BMDC were chosen to investigate the effect of C. pyruviciproducens on immunomodulation in vitro, and the stimulatory function of C. pyruviciproducens on dendritic cells was analyzed by detecting the levels of cytokine-secretion, ability of cell-proliferation and expression of membrane molecules. Furthermore, the effect of C. pyruviciproducens on promoting antibody production in mice was detected. It is hoped to develop a new bacterial adjuvant with higher power of regulating immune response.

Section snippets

Bacterial strains

P. acnes (ATCC6919, obtained from Guangdong Culture Collection Center, China) was cultured in Lysogeny broth (LB) medium in an anaerobic jar at 37 °C for 3 days; C. pyruviciproducens (CCUG 57046, obtained from Olive View Medicine Center, University of California, USA) was cultured in LB medium with 5% new-born calf serum (NCS) (Sigma, USA) at 37 °C for 3 days. Collected bacteria were washed three times by centrifugation (12,000 rpm, 10 min). The bacterial pellet was re-suspended in sterile saline

C. pyruviciproducens induced D2SC/1 and BMDC to produce more inflammatory cytokine secretions than P. acnes

mRNA levels (Fig. 1) and protein level (Fig. 2) of IL-6 and IL-12p40 secreted by D2SC/1 and BMDC were analyzed. Increasing amounts of IL-6 and IL-12p40 mRNA were found following growth with stimulating concentrations of both C. pyruviciproducens and P. acnes; however, C. pyruviciproducens showed a stronger influence in inducing cytokine expression than P. acnes (Fig. 1). ELISA results showed that D2SC/1 and BMDC responded to C. pyruviciproducens in a dose-responsive manner (100; 500; 1000 μg/ml)

Discussion

In this study, C. pyruviciproducens was verified in vitro as an active immunostimulatory adjuvant which enhanced secretion of IL-6, a potent Th2-biased inflammatory cytokine [12] and IL-12, a Th1 specific cytokine [13]. The effects of C. pyruviciproducens on DCs may be due to complex bacterial compositions like CpG oligonucleotides (ligand of TLR9), peptidoglycan and teichoic acid [14].

Our data also showed that C. pyruviciproducens was much capable of significantly promoting proliferation on

Acknowledgements

This work was supported by the National Natural Science Foundation of China (30871193, 30972748, 81101227), the Natural Science Foundation of Colleges and Universities in Jiangsu Province and Innovation Fund for candidate of doctor in Jiangsu Province (Grant nos. 09KJB310001 and CX09B_217Z, respectively).

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  • Cited by (8)

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    These authors contributed equally to this work.

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