Reduced numbers of vaccine-specific B cells in <i>L. sigmodontis</i>-infected mice.

<p>Six- to eight-week-old BALB/c mice were naturally infected with <i>L. sigmodontis</i> or left non-infected and vaccinated with 30 µg DNP-KLH/Alum s.c. at day 60 p.i. PopLN cells from DNP-KLH-vaccinated non-infected (white bars) and <i>L. sigmodontis</i>-infected (black bars) mice were stained for CD19, PNA-binding, DNP-binding, IgM and IgG at day 14 post vaccination. Mice had been infected for 60 days at the time point of vaccination. <b>(A)</b> Gating strategy of CD19⁺ B lymphocytes. <b>(B)</b>Total cell numbers of DNP⁺PNA⁺ lymph node cells within the CD19⁺ (total), within the IgG⁺IgM⁺CD19⁺ and within the IgG⁺CD19⁺ gate (n = 10–14). Results are expressed as mean ± SEM of pooled data derived from two independent experiments. Asterisks indicate significant differences between non-infected and infected mice (student's t-test).