RECOMBINANT POLYPEPTIDES BASED ON C5A PEPTIDASE AS POTENTIAL VACCINE COMPONENTS AGAINST GROUP B STREPTOCOCCI

Abstract

Аbstract. Gene fragments encoding N-terminal and central parts of group B streptococci (GBS) C5a peptidase were cloned in E. coli M15. The appropriate recombinant SCPB1a and SCPB3a polypeptides with molecular masses of, resp., 12.0±0.5 kDa and 11.0±0.5 kDa, were subject to expression and affinity purification. Both polypeptides induced specific antibodies production upon subcutaneous immunization of mice. A more pronounced immune response was detected with SCPB3a injection. Antimicrobial properties of anti-SCPB1a and anti-SCPB3a antibodies have been investigated in vitro (by opsonophagocytosis test) and in vivo (a model of generalized GBS infection in mice). N-terminal and central segments of C5a peptidase molecule have been shown to contain epitopes inducing humoral immune response with production of class G antibodies that efficiently opsonize GBS, whereas recombinant SCPB1a and SCPB3a polypeptides can be recommended for future implications in development of a polycomponent vaccine against GBS. (Med. Immunol., 2011, vol. 13, N 1, pp 41-48)

Keywords

• group b streptococci
• c5a peptidase
• recombinant polypeptides
• immunogenicity
• opsonophagocytosis