Expansion of myeloid-derived suppressor cells with arginase activity lasts longer in aged than in young mice after CpG-ODN plus IFA treatment

FLORENCIA HARMAN; ROMINA P. RANOCCHIA; CAROLINA GORLINO; FERNANDA SÁNCHEZ-VALLECILLO; SOFÍA CASTELL; MARÍA INÉS CRESPO; BELKYS A. MALETTO; G MORON; MARÍA C. PISTORESI-PALENCIA

Oncotarget

Impact Journals, LLC

Año: 2015 vol. 6 p. 13448 - 13461

As we age, thehomeostatic function of many systems in the body, such as the immune functiondeclines, which in turn contributes to augment susceptibility to disease. Herewe describe that challenging aged mice with synthetic oligodeoxynucleotides containingunmethylated cytosine guanine motifs (CpG-ODN) emulsified in incomplete Freund?sadjuvant (IFA), (CpG-ODN+IFA) an inflammatory stimulus, led to the expansion ofCD11b+Gr1+ myeloid cellswith augmented expression of CD124 and CD31. These myeloid cells lasted longerin the spleen of aged mice than in their younger counterparts after CpG-ODN+IFAtreatment and were capable of suppressing T cell proliferative response byarginase induction. Myeloid cells from aged CpG-ODN+IFAtreated mice presentedincreased arginase-1 expression and enzyme activity. In addition, we found adifferent requirement of cytokines for arginase induction according to miceage. In myeloid cells from young treated mice, arginase-1 expression and activityis induced by the presence of each IL-4 or IL-6 in their extracellular medium, unlikemyeloid cells from aged treated mice which need the presence of both IL-4 and IL-6together for arginase induction and suppressor function.