To examine if the reduced susceptibility of Sdc1-/- mice to listeriosis is attributable to enhanced innate immune responses, we tested the effects of depleting macrophages with clodronate liposomes and complement with cobra venom factor, and immunodepleting neutrophils with anti-Ly6G antibodies and T cells with anti-CD3 antibodies on Lm infection in Sdc1-/- mice. The gene discussed is SDC1; the disease is listeriosis.