title: Involvement of soluble scavenger receptor A in suppression of T cell activation in patients with chronic hepatitis B.
abstract: BACKGROUND
  Scavenger receptor A (SRA) is expressed predominantly in phagocytic cells playing an essential role in the host immune defense against invading microorganisms. Our previous study reported the presence of SRA in a soluble form in patients with infection of hepatitis B viruses (HBV). However, the association of soluble SRA with stages of HBV infection and the immune response induced by HBV is not fully determined.
  
  
  METHODS
  In this study, we detected soluble SRA in serum from 29 chronic hepatitis B (CHB) patients, 28 chronic HBV carriers in the immune tolerant (IT) stage, 33 in the HBeAg-negative inactive carrier (IC) stage, and 22 healthy controls (HCs), respectively. We further analyzed the correlation of detected soluble SRA to inflammation and serum viral load. In addition, we investigated the regulatory role of soluble SRA in T cell activation, especially in CD8(+) T cell response to HBV peptide.
  
  
  RESULTS
  We demonstrated that Median levels of serum soluble SRA in CHB and IT patients were significantly higher than those of IC patients and HCs. Additionally, the concentrations of soluble SRA were negatively correlated with alanine transaminase levels in CHB patients. We also found that serum concentration of SRA was decreased during telbivudine treatment. Expressed SRA extracellular domain suppressed HBV core peptide-stimulated interferon-γ and tumor necrosis factor-α production in CD8(+) T cells, and it bound to T cells in a higher frequency in CHB patients than in HCs. Furthermore, we observed that naïve human T cells stimulated by anti-CD3 and CD28 antibodies in the presence of the recombinant SRA protein had reduced activation and proliferation.
  
  
  CONCLUSIONS
  In summary, we determined the level of soluble SRA in different stages of CHB patients. SRA might inhibit T cell proliferation and activation as a soluble form. These results not only revealed a previously unknown feature of soluble SRA in CHB patients but also provided broad understanding of SRA in T cell activation.
authors.affiliation: Department of Immunology, School of Basic Medicine, Southern Medical University, Guangzhou, 510515, China. immucy@163.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China. huangzuxiong215@hotmail.com.cn.|Department of Hepatology, Affiliated Infectious Disease Hospital of Fujian Medical University, Fuzhou, China. huangzuxiong215@hotmail.com.cn.
authors.forename: Zuxiong
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Immunology, School of Basic Medicine, Southern Medical University, Guangzhou, 510515, China. mountainlife@sina.com.
authors.forename: Di
authors.initials: D
authors.lastname: Ma
authors.affiliation: Department of Immunology, School of Basic Medicine, Southern Medical University, Guangzhou, 510515, China. 1406361551@qq.com.
authors.forename: Liqian
authors.initials: L
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China. 363367565@qq.com.
authors.forename: Qintao
authors.initials: Q
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China. 38551976@qq.com.
authors.forename: Xuan
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Immunology, School of Basic Medicine, Southern Medical University, Guangzhou, 510515, China. yuguomm@smu.edu.cn.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China. xiaoyong.zhang@msn.com.
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Institute of Antibody Engineering, School of Biotechnology, Southern Medical University, Guangzhou, China. 51627800@qq.com.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ma
authors.affiliation: Department of Immunology, School of Basic Medicine, Southern Medical University, Guangzhou, 510515, China. zhlchen@smu.edu.cn.
authors.forename: Zhengliang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Immunology, School of Basic Medicine, Southern Medical University, Guangzhou, 510515, China. zdaming@smu.edu.cn.|State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China. zdaming@smu.edu.cn.
authors.forename: Daming
authors.initials: D
authors.lastname: Zuo
mesh_terms: D000293:Adolescent; D000328:Adult; D058070:Asymptomatic Diseases; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D018450:Disease Progression; D005260:Female; D019694:Hepatitis B, Chronic / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D010587:Phagocytosis; D051117:Scavenger Receptors, Class A / Q000097:blood*; D019562:Viral Load; D055815:Young Adult
chemical_list: D051117:Scavenger Receptors, Class A