Resumen:
The ability of synthetic oligodeoxynucleotides containing unmethylated cytosine guanine motifs (CpG-ODN) to induce both stimulatoryand counter-regulatory responses offers novel opportunities for using these molecules as immunomodulatory agents in differenttherapeutic strategies. Here, we investigated the potential of CpG-ODN to activate the arginase (ARG) enzyme in vivo and focused onthe consequences of this activation in T-cell proliferation. Challenging mice subcutaneously with CpG-ODN emulsified in incompleteFreund?s adjuvant (IFA) induced ARG and reduced T-cell proliferation associated with CD3f chain downregulation. Interestingly,impaired T-cell expansion correlated with elevated levels of CD11b+Gr1+ myeloid cells localized near T-cell areas in the spleen.In addition, purified CD11b+ cells obtained from the spleen of CpG-ODN+IFA-treated mice exhibited increased ARG activity andARG I expression along with an augmented [3H]-L-arginin