Lentinan relieves hepatitis B surface antigen induced functional impairment of monocytes/macrophages

Pei-Pei Fang,Jie Li,Guang-Yao Zhou,Shan-Shan Huang,Lingxiang Jin,Le Qin,Lu Zhuge,Chen-Wei Pan

doi:10.4314/tjpr.v17i4.3

Abstract

Purpose : To investigate the efficacy of lentinan in relieving hepatitis B surface antigen (HBsAg)- induced functional impairment of monocytes/macrophages. Methods : Monocytic cell line THP-1 was incubated with lentinan and HBsAg for 24 h and then stimulated with LPS (Lipopolysaccharide). The expression levels of interleukin-1β (IL-1β), IL-12 and tumour necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent (ELISA) assays and quantitative reverse transcriptase-PCR (q-PCR). Protein levels of IkB-α, phospho-ERK, and phospho-p38 were measured by western blotting. Results : THP-1 cells treated with lentinan and HBsAg showed higher IL-1β, IL-12, and TNF-α levels than cells treated with HBsAg alone. The underlying mechanisms were associated with NF-kB and MAPK signal pathways. Decreased expression of IkB-α and phospho-ERK and increased expression of phospho-JNK and phospho-p38 were observed in cells treated with lentinan and HBsAg when compared with cells treated with HBsAg alone (p < 0.001). THP-1 cells incubated with 500 μg/mL lentinan secreted lower levels of cytokines than did control cells after LPS stimulation, suggesting an anti-inflammatory effect for lentinan. Conclusion : Lentinan shows both pro- and anti-inflammatory functions and may be a promising candidate for hepatitis B virus (HBV) treatment. Keywords : Hepatitis B surface antigen, Lentinan, Immuno-suppression, Pro-inflammatory, Antiinflammatory

Highlights

Hepatitis B virus (HBV), a non-cytopathic DNA virus with a partially duplex circular genome of 3.2 kb, infects more than 350 million people worldwide [1,2]
To investigate if lentinan affects monocytes/macrophages treated with hepatitis B surface antigen (HBsAg), the protein concentrations of IL-1β, IL-12, and tumour necrosis factor-α (TNF-α) in THP-1 culture supernatants were measured by Enzyme-linked immunosorbent assay (ELISA) (Figure 1 A-C)
The results show that HBsAg repressed the expression of these cytokines at the mRNA and protein levels, indicating potent immuno-suppressive activity by lentinan (Figure 1 D-F)

Summary

INTRODUCTION

Hepatitis B virus (HBV), a non-cytopathic DNA virus with a partially duplex circular genome of 3.2 kb, infects more than 350 million people worldwide [1,2]. The cells were washed and stimulated with LPS (100 ng/mL) for 15 min or 6 h in complete RPMI 1640 medium. After LPS stimulation for 6 h, secreted IL-1β, IL12, and TNF-α levels were measured by ELISA kits (R & D Systems, USA) under the guidance of the manufacturer’s introduction. Lentinan was used to relieve HBsAg-induced impairment of cytokine secretion by THP-1 cells. Lentinan repressed cytokine production by THP-1 cells upon LPS stimulation. These data indicate that lentinan may be a promising candidate for HBV therapy. Polyclonal anti–phospho (p)-ERK, antiERK, and anti-IkB-α and monoclonal anti– phospho-JNK, anti–JUK, anti–p-p38, and anti– p38 were obtained from Cell Signaling Technology (Danvers, MA, USA). Membranes were incubated with HRP-conjugated goat anti-rabbit/mouse antibodies for 2 h at room temperature.

RESULTS

DISCUSSION

CONCLUSION

Conflict of Interest