Natural antibody responses to the capsid protein in sera of Dengue infected patients from Sri Lanka

• Published in: PloS one Vol. 12; no. 6; p. e0178009
• Main Authors: Nadugala, Mahesha N, Jeewandara, Chandima, Malavige, Gathsaurie N, Premaratne, Prasad H, Goonasekara, Charitha L
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 05-06-2017; Public Library of Science (PLoS)
• Subjects: Accessibility; Adolescent; Adult; Aged; Amino Acid Sequence; Amino acids; Antibodies; Antibodies, Viral - biosynthesis; Antibodies, Viral - chemistry; Antibody response; Antigenicity; Antigens; Antigens, Viral - chemistry; Antigens, Viral - genetics; Antigens, Viral - immunology; Antisera; Binding Sites; Biology and Life Sciences; C protein; Capsid protein; Capsid Proteins - chemistry; Capsid Proteins - genetics; Capsid Proteins - immunology; Care and treatment; Child; Dengue; Dengue - immunology; Dengue - virology; Dengue fever; Dengue virus; Dengue Virus - classification; Dengue Virus - genetics; Dengue Virus - immunology; Dosage and administration; Enzyme-linked immunosorbent assay; Epitope Mapping; Epitopes; Epitopes - chemistry; Epitopes - genetics; Exposure; Female; Flexibility; Genomes; Health aspects; Humans; Hydrophilicity; Immune Sera - chemistry; Immune serum; Immunity, Innate; Immunoglobulins; Infections; Lymphocytes B; Male; Medicine and Health Sciences; Methods; Middle Aged; Patients; Peptides; Peptides - chemistry; Peptides - genetics; Peptides - immunology; Phylogenetics; Phylogeny; Predictions; Prevention; Protein Binding; Protein Interaction Domains and Motifs; Protein structure; Protein Structure, Secondary; Proteins; Research and Analysis Methods; Serogroup; Serotypes; Sri Lanka; Vector-borne diseases; Viral diseases; Viral infections; Viral proteins; Viruses; Sri Lanka
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0178009

This study aims to characterize the antigenicity of the Capsid (C) protein and the human antibody responses to C protein from the four dengue virus (DENV) serotypes. Parker hydrophilicity prediction, Emini surface accessibility prediction and Karplus & Schulz flexibility predictions were used to bioinformatically characterize antigenicity. The human antibody response to C protein was assessed by ELISA using immune sera and an array of overlapping DENV2 C peptides. DENV2 C protein peptides P1 (located on C protein at 2-18 a.a), P11 (79-95 a.a) and P12 (86-101 a.a) were recognized by most individuals exposed to infections with only one of the 4 DENV serotypes as well as people exposed to infections with two serotypes. These conserved peptide epitopes are located on the amino (1-40 a.a) and carboxy (70-100 a.a) terminal regions of C protein, which were predicted to be antigenic using different bioinformatic tools. DENV2 C peptide P6 (39-56 a.a) was recognized by all individuals exposed to DENV2 infections, some individuals exposed to DENV4 infections and none of the individuals exposed to DENV1 or 3 infections. Thus, unlike C peptides P1, P11 and P12, which contain epitopes, recognized by DENV serotype cross-reactive antibodies, DENV2 peptide P6 contains an epitope that is preferentially recognized by antibodies in people exposed to this serotype compared to other serotypes. We discuss our results in the context of the known structure of C protein and recent work on the human B-cell response to DENV infection.