Fig. 1.

Doxycycline inhibits lymphocyte proliferation. Ex vivo splenocytes were cultured in medium alone, medium containing an optimal concentration of Lactobacillus casei cell wall extract (LCWE) or LCWE plus various concentrations of doxycycline for 72 h. Cells were pulsed with [³H]-thymidine for the last 18 h of culture. Thymidine incorporation was assessed using a scintillation counter. Data are presented as the mean DPM ± standard error of the mean of triplicate cultures (representative of three independent experiments; *P < 0·05 compared to LCWE alone). DPM, disintegrations per minute.