Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine known to activate macrophages and T cells. In this study, we demonstrate that recombinant MIF delays apoptosis of neutrophils in vitro. MIF action is dose and time dependent as well as specific since it was abolished with a neutralizing anti-MIF antibody. MIF, like G-CSF, delayed cleavage of the proapoptotic members of the Bcl-2 family Bid and Bax in neutrophils, suggesting that MIF inhibits apoptosis pathways proximal to mitochondria activation. Indeed, MIF also prevented release of cytochrome c and Smac from the mitochondria and subsequent activation of the critical effector caspase-3 in these cells. Moreover, we observed increased MIF plasma levels in patients with cystic fibrosis, a heterogeneous recessive genetic disorder associated with bacterial infections and delayed neutrophil apoptosis. In conclusion, MIF is a survival cytokine for human neutrophils, a finding with potential pathologic relevance in infectious diseases.

Graft-vs-host disease (GVHD) is a potentially treatable cause of progressive neurologic decline after bone marrow transplantation (BMT). The authors present histologic confirmation of CNS granulomatous angiitis in a child with chronic GVHD after BMT. Since cranial MRI showed only nonspecific findings, CNS vasculitis associated with GVHD after BMT may be underdiagnosed.

CD134 (OX40) is a member of the tumor necrosis factor (TNF) receptor superfamily expressed on activated T cells. Here, we show that human peripheral blood neutrophils express CD134. Activation of CD134 by soluble CD134 ligand (OX40 ligand/gp34) resulted in delayed caspase-3 activation and consequently in delayed neutrophil apoptosis in vitro. Moreover, CD134 ligand, like G-CSF, maintained anti-apoptotic Mcl-1 levels and inhibited cleavage of the pro-apoptotic Bcl-2 family members Bid and Bax in these cells, suggesting that CD134-mediated signals block apoptosis pathways proximal to mitochondria activation. In conclusion, CD134 regulates neutrophil survival, suggesting that this molecule does not only contribute to adaptive but also to innate immune responses.

SummaryThe immune responses against pulmonary tuberculosis are still poorly defined. This study describes changes in leucocyte and lymphocyte subsets during treatment to find reliable immunological markers for the disease and treatment response.

Nasal IL-17, MCP-4, and, possibly, eotaxin-3 may aggravate and IL-10 may alleviate nasal mucosal allergy.