Identification of murine T-cell epitopes on the S4 subunit of pertussis toxin

Abstract

The aim of the present study was to identify murine T-cell epitopes on pertussis toxin subunit S4. Six mouse strains with five different haplotypes at the H-2 locus were immunized with the pertussis toxin B oligomer. Lymph node lymphocytes were isolated and stimulated in an in vitro proliferation assay with pertussis toxin components and 11 overlapping synthetic peptides synthesized on the basis of the primary sequence of S4. In vitro proliferative responses to the synthetic peptides revealed the presence of four distinct murine T-cell epitopes on subunit S4. The recognition of the peptides was major histocompatibility complex restricted.Immunizing four of the six mouse strains with the synthetic peptides showed that the peptides which were demonstrated to contain T-cell epitopes following immunization with the B oligomer were able to induce proliferative responses to detoxified pertussis toxin and pertussis toxin components containing subunit S4. One of the identified murine T-cell epitopes corresponded to one of the major human T-cell epitopes previously identified on subunit S4. It is hoped that this murine model system will facilitate the development of a synthetic immunogen mimicking the protective properties of pertussis toxin.

Pertussis-specific cell-mediated immunity in infants after vaccination with a tricomponent acellular pertussis vaccine

“…Similarly, CMI responses have been demonstrated in mice following parenteral (36,37) or mucosal (29) immunization or after infection (39). The reported variability of CMI responses to detoxified PT, especially in animal models (29,36,37), may be related to a different alteration of the toxoid by the detoxification process that in consequence may have influenced its quality as a specific antigen. Furthermore, experimental pertussis in mice (34,47) located in the upper respiratory tract and lungs differs from infection in humans, which is almost exclusively located in the ciliated epithelium of the upper respiratory tract (25).…”

“…CELL-MEDIATED IMMUNITY AFTER PERTUSSIS VACCINES 4081 after infection (11)(12)(13)(14)17) or following vaccination (38,40). Similarly, CMI responses have been demonstrated in mice following parenteral (36,37) or mucosal (29) immunization or after infection (39). The reported variability of CMI responses to detoxified PT, especially in animal models (29,36,37), may be related to a different alteration of the toxoid by the detoxification process that in consequence may have influenced its quality as a specific antigen.…”

“…In mice, pertussis-specific T-cell-mediated immune responses were demonstrated after infection (29) or following immunization (36,37). Mills et al (30) recently demonstrated that the adoptive transfer of splenic T cells or purified CD4positive T cells from immune mice can confer protection against B. pertussis to immunodeficient mice in the absence of a detectable antibody response.…”

Identification of B-cell epitopes on the S4 subunit of pertussis toxin

“…HPLC, indicating a purity as follows, given as a percentage, with the peptide numbers (Table 1) given in parentheses: 90 to 100 (8,12,17,18,28,30,31,32,33,35,36,39,44); 80 to 89 (1, 6, 9, 10, 11, 15,16,21,24,25,26,27,34,37,38,40,47,49); 70 to 79 (2, 4,5,7,14,19,22,23,29,41,42,43,48); 60 to 69 (3, 13); 50 to 59 (20, 45, 50). In most cases a single major component was observed, but compound 46 gave two major (30 and 40%) and two minor peaks.…”

“…In recent years, the identification of Bas well as T-cell epitopes on the PT subunits Si, S2, and S3 by the synthetic peptide approach has been described (3, 4, 9, 17, 31, 41, 43). In our laboratory, two major and one minor human T-cell epitope as well as four murine T-cell epitopes on the S4 subunit have been identified (34,35). The main purpose of the present study was to identify B-cell epitopes on the S4 subunit of PT.…”