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

RANOCCHIA, R; GORLINO, C; CRESPO, MI; HARMAN, MF; LISCOVSKY, M; MORÓN, G; MALETTO, B; PISTORESI, MC

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 proliferation. Challenging mice via s.c. with CpG-ODN emulsified in incomplete Freund´s adjuvant (IFA) induced ARG and reduced T cell proliferation associated with CD3ζ chain down-regulation. Interestingly, impaired T cell expansion correlated with elevated levels of CD11b+Gr1+ myeloid cells localized near T-cell areas in spleen. 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 augmented [3H]-L-arginine uptake. CD11b+ myeloid cells significantly s