CD4 T-helper cell cytokine phenotypes following tetanus toxoid immunization (52.3)

Abstract Routine methods for enumerating antigen-specific T-helper cells may not identify low-frequency phenotypes such as Th2 cells. We compared methods of evaluating such responses to identify TT-specific Th1, Th2, Th17 and IL10+ cells. Eight healthy subjects were given a TT booster vaccination. Blood was drawn before, 3, 7, 14, and 28d after vaccination. PBMC cultures were stimulated with TT or PBS. Activation markers (CD25 and CD69) were measured after 44h (n=8), cytokines in supernatant after 3 and 7d of culture, and intracellular cytokine staining (ICS) was performed in proliferated cells (PKH67 dye dilution) after 7d of culture (n=6). Vaccination increased TT-specific expression of CD25 and CD69 on CD3+CD4+ lymphocytes, and TT-specific proliferation at 7, 14 and 28d post vaccination. Vaccination induced TT-specific Th1 (IFNγ, TNFα, and IL2) Th2 (IL13, IL5, and IL4), Th17 (IL17A) and IL10+ cells as measured by ICS. TT-specific Th1 cells were the most abundant (12-15% of all CD3+CD4+ T-cells) while IL10+ (1.8%) Th17 (1.1%) and Th2 cells (0.2-0.6%) were less abundant. TT-specific cytokine concentrations in PBMC supernatants followed the same pattern. A TT-specific IL-9 response was also seen in the supernatants. In conclusion, TT booster vaccination induced a broad T-helper cell response. This method of evaluating cytokine phenotypes may be useful in examining the impact of nutrition and environmental conditions on the plasticity of T-helper cell memory responses.