Intravenous immunoglobulin injection modulates the relative populations of T lymphocytes. Flow cytometry analyses on splenocytes labeled for regulatory (CD4+, CD25+ and Foxp3+) iCOS+CD4+ (CD62L low, CD4+, iCOS+ and Foxp3+), helper (CD4+) and cytotoxic (CD8+) T cells. (A) Representative plots showing regulatory T cell (Treg; upper panels, gated on CD4+ cells) iCOS+CD4+ (middle panels, gated on CD4+/CD62L low cells) and CD4+/CD8+ (lower panels, gated on CD3+ cells) analyses. (B) Intravenous immunoglobulin (IVIg) induced a mild but significant increase in Treg relative population but not in (C) iCOS+/Foxp3+ or (D) iCOS+ populations. IVIg treatment also decreased the (E) CD4+/CD8+ cell ratio. (B) to (E) Results are presented as mean ± standard error of the mean (10 to 15 animals). Statistical analysis: *P <0.05 versus vehicle-control group, one-way analysis of variance (ANOVA), followed by Dunnett’s multiple comparison test, ∞
P <0.05 IVIg versus control, two-way ANOVA.