Severe H7N9 infection is associated with decreased antigen-presenting capacity of CD14+ cells

• Published in: PloS one Vol. 9; no. 3; p. e92823
• Main Authors: Diao, Hongyan, Cui, Guangying, Wei, Yingfeng, Chen, Jianing, Zuo, Jian, Cao, Hongcui, Chen, Yu, Yao, Hangping, Tian, Zhigang, Li, Lanjuan
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 24.03.2014; Public Library of Science (PLoS)
• Subjects: Adult; Aged; Aged, 80 and over; Antigen Presentation; Antigen-Presenting Cells - immunology; Antigen-Presenting Cells - pathology; Antigens; Avian flu; Bioindicators; Biology and Life Sciences; Biomarkers; CD14 antigen; Cell activation; Chemokines; Collaboration; Cytokines; Female; Histocompatibility antigen HLA; HLA-DR Antigens - immunology; Hospitals; Humans; Immunology; Infections; Infectious diseases; Influenza A Virus, H7N9 Subtype - immunology; Influenza, Human - immunology; Influenza, Human - pathology; Laboratories; Lipopolysaccharide Receptors - immunology; Lymphocytes; Lymphocytes T; Lymphopenia; Male; Medical diagnosis; Medicine; Medicine and Health Sciences; Middle Aged; Monocytes; Outbreaks; Pandemics; Patients; Phagocytosis; Physiology; Severity of Illness Index; Studies; T-Lymphocytes - immunology; T-Lymphocytes - pathology; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0092823

The outbreak of H7N9 human infection has caused concern worldwide, but the immunological characteristics of infected patients and the determinants of diverse outcomes remain to be thoroughly understood. In this study, twenty-three patients with H7N9 infections were classified into severe and mild cases. We found that severe patients were commonly lymphopenic with significantly lower levels of T cells, monocytes and related cytokine levels compared to the mild cases. The expression of HLA-DR on CD14+ cells were significantly lower in the severe infection group compared to the mild group (in acute phase: 34.65±4.88 vs. 10.37±1.69, p<0.001). Importantly, the expression of HLA-DR on CD14+ cells was negatively correlated with H7N9 infection severity. Furthermore, although the phagocytosis capabilities of monocyte were similar between two groups, the monocytes of severe infection patients had a lower antigen-presenting capacity. And some in vitro experiments suggested that the impaired antigen-presenting function is associated with lower activation of T cells in responses to immune stimulation. Our present study suggested that the severe H7N9 patients were in a state of immune decrease which presented with general lymphopenia and low antigen-presenting capacity resulting in impaired T cell response. Additionally, HLA-DR levels of CD14+ cells may be a potential biomarker for predicting H7N9 disease progression.