| First Author | Makarenkova VP | Year | 2006 |
| Journal | J Immunol | Volume | 176 |
| Issue | 4 | Pages | 2085-94 |
| PubMed ID | 16455964 | Mgi Jnum | J:129127 |
| Mgi Id | MGI:3768719 | Doi | 10.4049/jimmunol.176.4.2085 |
| Citation | Makarenkova VP, et al. (2006) CD11b+/Gr-1+ myeloid suppressor cells cause T cell dysfunction after traumatic stress. J Immunol 176(4):2085-94 |
| abstractText | T cell dysfunction that occurs after surgery or trauma is associated with a poor clinical outcome. We describe that myeloid suppressor cells expressing CD11b(+)/Gr-1(+) markers invade the spleen after traumatic stress and suppress T cell function through the production of arginase 1. We created a consistent model of traumatic stress in C57BL/6 mice to perform this work. A significant number of CD11b(+)/Gr-1(+) cells expressing arginase 1 accumulated in T cell zones around the germinal centers of the white pulp of the spleen within 6 h of trauma and lasted for at least 72 h. Increased arginase activity and arginase 1 expression, along with increased [(3)H]arginine uptake, l-arginine depletion, and l-ornithine accumulation in the culture medium, were observed exclusively in CD11b(+)/Gr-1(+) cells after traumatic stress. Flow cytometry revealed CD11b(+)/Gr-1(+) as a heterogeneous myeloid suppressor cell also expressing low levels of MHC class I and II, CD80, CD86, CD31, and others. When compared with controls, trauma-induced CD11b(+)/Gr-1(+) cells significantly inhibited CD3/CD28-mediated T cell proliferation, TCR zeta-chain expression, and IL-2 production. The suppressive effects by trauma CD11b(+)/Gr-1(+) cells were overcome with the arginase antagonist N-hydroxy-nor-l-arginine or extrasupplementation of medium with l-arginine. Poor Ag-presenting capacity of control and trauma-induced CD11b(+)/Gr-1(+) cells was detected in allogeneic murine leukocyte reaction. This study demonstrates that CD11b(+)/Gr-1(+) cells invade the spleen following traumatic stress and cause T cell dysfunction by an arginase-mediated mechanism, probably that of arginine depletion. Understanding the mechanism of immune suppression by these cells has important clinical implications in the treatment of immune dysfunction after trauma or surgery. |
