Faculty Bibliography

The neutrophil is a critical effector cell in humoral and innate immunity and plays vital roles in phagocytosis and bacterial killing. Discussed here are the neutrophil components necessary for these processes and the diseases in which these components are either lacking or dysfunctional, illustrating that normal neutrophil function is vital for health.

GM-CSF has a major role in the immune and inflammatory milieu of the airway. Airway epithelial cells (AEC) are among the first targets of environmental stimuli and local cytokines, in response to which they can produce GM-CSF. The regulation of GM-CSF is only minimally understood in AEC. We hypothesized that GM-CSF expression in AEC would result from activation of protein kinase C (PKC) and subsequent activation of the extracellular signal-regulated kinase (MAPKerk1/2) pathway, so we investigated signal transduction pathways in human primary culture bronchial epithelial cells (HBECs). TNF-alpha, IL-1beta, and PMA induced the release of GM-CSF in HBECs. The robust response to PMA was not detected in SV40 adenovirus-transformed normal human bronchial epithelial cells (BEAS-2B). PMA and TNF-alpha stimulation of GM-CSF required activation of PKC (inhibition by staurosporine and bisindolylmaleimide I). GM-CSF expression was up-regulated by a nonphorbol PKC activator, but not by an inactive PMA analogue. PMA-induced GM-CSF production in HBECs did not require a Ca2+ ionophore and was not inhibited by cyclosporin A. Activation of MAPKerk1/2 via PKC was associated with and was required for GM-CSF production induced by PMA and TNF-alpha. The data demonstrate regulation of GM-CSF in HBECs by PKC pathways converging on the MAPKerk1/2 pathway and further define cell-specific regulation critical for local airway responses

The anti-inflammatory effects of high-dose salicylates are well recognized, incompletely understood and unlikely due entirely to cyclooxygenase (COX) inhibition. We have previously reported a role for activation of the kinase Erk in CD11b/CD18 integrin-dependent adhesiveness of human neutrophils, a critical step in inflammation. We now report the effects of salicylates on neutrophil Erk and adhesion. Exposure of neutrophils to aspirin or sodium salicylate (poor COX inhibitor) inhibited Erk activity and adhesiveness of formylmethionyl-leucyl-phenylalanine- and arachidonic acid-stimulated neutrophils, consistent with anti-inflammation but not COX inhibition (IC50s = 1-8 mM). In contrast, indomethacin blocked neither Erk nor adhesion. Inhibition of Mek (proximal activator of Erk) also blocked stimulation of Erk and adhesion by formylmethionyl-leucyl-phenylalanineand arachidonic acid. Salicylate inhibition of Erk was independent of protein kinase A activation and generation of extracellular adenosine. These data are consistent with a role for Erk in stimulated neutrophil adhesion, and suggest that anti-inflammatory effects of salicylates may be mediated via inhibition of Erk signaling required for integrin-mediated responses

CONTEXT: The use of propylthiouracil (PTU) in patients with Graves' disease has been associated with multiple complications including rash, leukocytoclastic vasculitis, pulmonary hemorrhage, glomerulonephritis, and the presence of perinuclear antineutrophilic cytoplasmic antibodies (pANCA). OBJECTIVES: To report the association of Wegener's granulomatosis (WG) with the use of PTU in a patient with Graves' disease and to review the spectrum of systemic vasculitis seen in patients with Graves' disease taking PTU. DESIGN: Retrospective review of data collected in a patient with WG. In addition, a Medline search (1980 to present) for PTU-associated vasculitis was conducted. RESULTS: We report WG in a patient treated with PTU who fulfilled the criteria of the American College of Rheumatology for this disease. Furthermore, his serum was positive for cytosolic antineutrophil cytoplasmic antibodies (cANCA) and anti-proteinase-3 (PR3) antibodies by indirect immunofluorescence and enzyme linked immunosorbent assay (ELISA), respectively. WG is associated with high morbidity and mortality and usually requires extensive therapy with prednisone and cyclophosphamide. Our patient, however, did not need specific therapy except discontinuation of PTU to make a full recovery. In previous reports, PTU has been associated with different forms of vasculitis, but this is a the first description of classic WG in a patient treated with PTU. CONCLUSIONS: PTU is capable of causing WG in susceptible patients with Graves' disease. Our patient did not require specific therapy for vasculitis and improved after discontinuation of PTU