title: Biochemical characterization and evaluation of a Brugia malayi small heat shock protein as a vaccine against lymphatic filariasis.
abstract: Filarial nematodes enjoy one of the longest life spans of any human pathogen due to effective immune evasion strategies developed by the parasite. Among the various immune evasion strategies exhibited by the parasite, Interleukin 10 (IL-10) productions and IL-10 mediated immune suppression has significant negative impact on the host immune system. Recently, we identified a small heat shock protein expressed by Brugia malayi (BmHsp12.6) that can bind to soluble human IL-10 receptor alpha (IL-10R) and activate IL-10 mediated effects in cell lines. In this study we show that the IL-10R binding region of BmHsp12.6 is localized to its N-terminal region. This region has significant sequence similarity to the receptor binding region of human IL-10. In vitro studies confirm that the N-terminal region of BmHsp12.6 (N-BmHsp12.6) has IL-10 like activity and the region containing the alpha crystalline domain and C-terminus of BmHsp12.6 (BmHsp12.6αc) has no IL-10 like activity. However, BmHsp12.6αc contains B cell, T cell and CTL epitopes. Members of the sHSP families are excellent vaccine candidates. Evaluation of sera samples from putatively immune endemic normal (EN) subjects showed IgG1 and IgG3 antibodies against BmHsp12.6αc and these antibodies were involved in the ADCC mediated protection. Subsequent vaccination trials with BmHsp12.6αc in a mouse model using a heterologous prime boost approach showed that 83% protection can be achieved against B. malayi L3 challenge. Results presented in this study thus show that the N-BmHsp12.6 subunit of BmHsp12.6 has immunoregulatory function, whereas, the BmHsp12.6αc subunit of BmHsp12.6 has significant vaccine potential.
authors.affiliation: Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, Illinois, United States of America.
authors.forename: Gajalakshmi
authors.initials: G
authors.lastname: Dakshinamoorthy
authors.forename: Abhilash Kumble
authors.initials: AK
authors.lastname: Samykutty
authors.forename: Gnanasekar
authors.initials: G
authors.lastname: Munirathinam
authors.forename: Gangadhar Bhaurao
authors.initials: GB
authors.lastname: Shinde
authors.forename: Thomas
authors.initials: T
authors.lastname: Nutman
authors.forename: Maryada Venkatarami
authors.initials: MV
authors.lastname: Reddy
authors.forename: Ramaswamy
authors.initials: R
authors.lastname: Kalyanasundaram
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood / Q000276:immunology; D000920:Antibody-Dependent Cell Cytotoxicity; D000947:Antigens, Helminth / Q000276:immunology; D017178:Brugia malayi / Q000276:immunology*; D049109:Cell Proliferation; D016207:Cytokines / Q000378:metabolism; D004605:Elephantiasis, Filarial / Q000276:immunology* / Q000517:prevention & control*; D050888:Heat-Shock Proteins, Small / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology / Q000378:metabolism; D008297:Male; D008407:Mast Cells / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology*; D053701:Receptors, Interleukin-10 / Q000276:immunology / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D014611:Vaccination; D019444:Vaccines, DNA / Q000627:therapeutic use*
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D016207:Cytokines; D050888:Heat-Shock Proteins, Small; D007074:Immunoglobulin G; D010446:Peptide Fragments; D053701:Receptors, Interleukin-10; D011994:Recombinant Proteins; D019444:Vaccines, DNA; D016753:Interleukin-10