VLA-4 is required for efficient control of <i>L. donovani</i> infection in the liver.

<p>Female C57BL/6 mice were treated with anti-VLA-4 mAb (closed bars) or control rat IgG (open bars) and infected with 2×10⁷<i>L. donovani</i> amastigotes i.v. Mice were injected i.p. with 1 mg of antibody prior to infection and every 3 days thereafter. Parasite burdens were determined in the liver at day 14 p.i. (A) and data represent the mean±SEM in Leishman Donovan units. The number and maturity of hepatic granulomas was estimated on day 14 liver sections stained with anti-<i>L. donovani</i> sera (B). Data represent the frequency of infected Kupffer cells (KC), immature granulomas (IG) and mature granulomas (MG) per liver. Hepatic mononuclear cells were isolated from naïve (hatched bars) and infected mice on day 14 p.i. and enumerated (C). mRNA was extracted from livers of naïve (hatched bars) or day 14 p.i. VLA-4 blocked (closed bars) or control mice (open bars), and accumulation of IFNγ (D), TNF (E) and NOS-2 (F) mRNA was detected by real-time RT-PCR and is expressed as mRNA molecule per 1000 HPRT molecules. One representative experiment of two performed with similar outcome is shown (n = 4 mice per treatment group in each experiment). Statistical differences of p<0.05 (*) or p<0.01 (**) for control versus anti-VLA-4 treatment are indicated.