Arginase-dependent suppression by CpG-ODN plus IFA-induced splenic myeloid CD11b(+)Gr1(+) cells

R. RANOCCHIA; C. GORLINO; M. I. CRESPO; F. HARMAN; M. LISCOVSKY; G. MORÓN; B. MALETTO; M. C. PISTORESI-PALENCIA

NATURE PUBLISHING GROUP

Año: 2012 vol. 90 p. 710 - 710

he ability of synthetic oligodeoxynucleotides containing unmethylated cytosine guanine motifs (CpG-ODN) to induce both stimulatory and counter-regulatory responses offers novel opportunities for using these molecules as immunomodulatory agents in different therapeutic strategies. Here, we investigated the potential of CpG-ODN to activate the arginase (ARG) enzyme in vivo and focused on the consequences of this activation in T cell responses. Challenging BALB/c mice with CpG-ODN emulsified in IFA, via s.c., induced ARG and a reduced T cell proliferation associated with CD3ä chain down-regulation. Interestingly, T cell hyporesponsiveness correlated with elevated levels of CD11b+Gr1+ myeloid cells in spleen localized near T-cell areas. In addition, purified CD11b+ cells obtained from the spleen of CpG-ODN+IFA-treated mice exhibited increased ARG activity and ARG I expression along with an increased [3H]-L-arginine uptake. CD11b+ myeloid cells significantly suppressed the T cell prolifera