Identification of immunodominant B- and T-cell combined epitopes in outer membrane lipoproteins LipL32 and LipL21 of Leptospira interrogans.
Leptospirosis is a serious infectious disease caused by pathogenic Leptospira. B- and T-cell-mediated immune responses contribute to the mechanisms of Leptospira interrogans infection and immune intervention. LipL32 and LipL21 are the conserved outer membrane lipoproteins of L. interrogans and are considered vaccine candidates. In this study, we identified B- and T-cell combined epitopes within LipL32 and LipL21 to further develop a novel vaccine. By using a computer prediction algorithm, two B- and T-cell combined epitopes of LipL21 and four of LipL32 were predicted. All of the predicted epitopes were expressed in a phage display system. Four epitopes, LipL21 residues 97 to 112 and 176 to 184 (LipL21(97-112) and LipL21(176-184), respectively) and LipL32(133-160) and LipL32(221-247) of LipL32 were selected as antigens by Western blotting and enzyme-linked immunosorbent assay. These selected epitopes were also recognized by CD4(+) T lymphocytes derived from LipL21- or LipL32-immunized BALB/c (H-2(d)) mice and mainly polarized the immune response toward a Th1 phenotype. The identification of epitopes that have both B- and T-cell immune reactivities is of value for studying the immune mechanisms in response to leptospiral infection and for designing an effective vaccine for leptospirosis.
Lin
Xu'ai
X
Department of Medical Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou 310058, China.
Zhao
Jinfang
J
Qian
Jing
J
Mao
Yafei
Y
Pan
Jianping
J
Li
Liwei
L
Peng
Huiqin
H
Luo
Yihui
Y
Yan
Jie
J
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology; D015153:Blotting, Western; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D019295:Computational Biology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000235:genetics / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology*; D005260:Female; D008074:Lipoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D004269:DNA, Bacterial; D018985:Epitopes, B-Lymphocyte; D018984:Epitopes, T-Lymphocyte; C545585:LipL21 protein, Leptospira interrogans; C406589:LipL32 protein, Leptospira; D008074:Lipoproteins