Different recall pertussis responses in mice immunized with different vaccines

CASTRO MS; PIUDO L; LAVIGNE MV; DELUCHI S; ATZORI C; MATEO N; BRERO ML; MANGHI MA

Stockholm, Sweden

Congreso; International Congress of Immunology; 2001

Asociación Latinoamericana de Inmunología

Considering that the murine model correlates with pertussis vaccines efficacy in children and due to the controversial results reported so far, here we compare the recall pertussis response generated by diphtheria, tetanus and whole-cell or acellular pertussis vaccines (DTPw and DTPa). Balb/c mice were sc inoculated with DTPw, DTPa or PS. Spleen cell cultures were stimulated with Bp or a mixture of soluble pertussis antigens (PT, FHA and PRN). T-cell proliferation ([3H]thymidine incorporation) and IFNã, IL-5 and IL-12 (ELISA) were measured. Both stimuli were proliferative for DTPw primed cells but only soluble antigens for DTPa. Bp was not recognized by DTPa primed cells. A Th1/Th2 pattern (IL-5 and IFNã) was observed with all stimuli in the case of DTPw priming. Conversely, a Th2 pattern (only IL-5) was found with soluble antigens for DTPa primed cells. Without any stimuli, similar IL-12 levels were observed in DTPa vs control group. The 2-fold higher IL-12 level found in DTPw is in line with the presence of Th1 cells (p<0.05). Our findings suggest that the reason for the reported lower efficacy of DTPa is due to the failure of this vaccine to generate memory Th1 cells which are necessary to clear intracellular Bp. (PICT 0504866;UBA TB47)