Identification of pertussis-specific effector memory T cells in preschool children

L De Rond, RM Schure, K Öztürk… - Clinical and Vaccine …, 2015 - Am Soc Microbiol
L De Rond, RM Schure, K Öztürk, G Berbers, E Sanders, I Van Twillert, M Carollo, F Mascart…
Clinical and Vaccine Immunology, 2015Am Soc Microbiol
Whooping cough remains a problem despite vaccination, and worldwide resurgence of
pertussis is evident. Since cellular immunity plays a role in long-term protection against
pertussis, we studied pertussis-specific T-cell responses. Around the time of the preschool
acellular pertussis (aP) booster dose at 4 years of age, T-cell memory responses were
compared in children who were primed during infancy with either a whole-cell pertussis (wP)
or an aP vaccine. Peripheral blood mononuclear cells (PBMCs) were isolated and …
Abstract
Whooping cough remains a problem despite vaccination, and worldwide resurgence of pertussis is evident. Since cellular immunity plays a role in long-term protection against pertussis, we studied pertussis-specific T-cell responses. Around the time of the preschool acellular pertussis (aP) booster dose at 4 years of age, T-cell memory responses were compared in children who were primed during infancy with either a whole-cell pertussis (wP) or an aP vaccine. Peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with pertussis vaccine antigens for 5 days. T cells were characterized by flow-based analysis of carboxyfluorescein succinimidyl ester (CFSE) dilution and CD4, CD3, CD45RA, CCR7, gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) expression. Before the aP preschool booster vaccination, both the proliferated pertussis toxin (PT)-specific CD4+ and CD8+ T-cell fractions (CFSEdim) were higher in aP- than in wP-primed children. Post-booster vaccination, more pertussis-specific CD4+ effector memory cells (CD45RA CCR7) were induced in aP-primed children than in those primed with wP. The booster vaccination did not appear to significantly affect the T-cell memory subsets and functionality in aP-primed or wP-primed children. Although the percentages of Th1 cytokine-producing cells were alike in aP- and wP-primed children pre-booster vaccination, aP-primed children produced more Th1 cytokines due to higher numbers of proliferated pertussis-specific effector memory cells. At present, infant vaccinations with four aP vaccines in the first year of life result in pertussis-specific CD4+ and CD8+ effector memory T-cell responses that persist in children until 4 years of age and are higher than those in wP-primed children. The booster at 4 years of age is therefore questionable; this may be postponed to 6 years of age.
American Society for Microbiology