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G B Huffnagle

Publications and source records attributed to G B Huffnagle.

40 records · Page 3Linked to original sources
PubMed1986

Characterization of a colony-stimulating factor produced by the human monocytic leukemia cell line, THP-1.

The human monocytic leukemia cell line, THP-1, acquires macrophage-like characteristics following exposure to mezerein. Serum-free medium conditioned by mezerein-activated cells was observed to contain colony-stimulating factor (CSF) activity in assays with murine bone marrow cultures. Isoelectrofocusing revealed that CSF activity displayed charge heterogeneity and migrated in a pl range of 4.4-5.3. Treatment with neuraminidase did not affect biological activity but did reduce charge heterogeneity. Reisofocusing of neuraminidase-treated CSF revealed a peak of activity at pl 4.9. The active component was shown to be an acidic sialoglycoprotein, resistant to proteolytic cleavage but completely inactivated by 2-mercaptoethanol. This CSF has been purified from THP-1-conditioned serum-free medium by preparative isoelectrofocusing, gel filtration through Sephacryl S-200, ion exchange chromatography on DEAE-Sephacel, neuraminidase treatment, and tris-glycinate polyacrylamide gel electrophoresis (PAGE). Elution from SDS-PAGE revealed a single peak of activity corresponding to an apparent molecular weight of 70,000 daltons. Preliminary characterization of the bone marrow cells in colonies showed that THP-1 cells produced macrophage-specific CSF.

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PubMedDate not supplied

Regulation of 5-lipoxygenase metabolism in mononuclear phagocytes by CD4 T lymphocytes.

Alveolar macrophages (AM) are the primary resident effector cells in the alveolus. Leukotrienes (LT) are secreted by AM in their role as defender of the lung. 5-Lipoxygenase (5-LO) catalyzes the synthesis of LT in association with 5-LO-activating protein, termed "FLAP." AM demonstrate increased 5-LO metabolism compared to peripheral blood monocytes (PBM). Activated lymphocytes release mediators which upregulate 5-LO metabolism in PBM. The lymphocyte population of the lung consists predominantly of CD4+ helper constitutively "activated" T cells. We hypothesized that mediators released by pulmonary CD4+ T cells may upregulate and maintain of 5-LO metabolism in PBM as they enter the alveolar space and differentiate into AM. 5-LO metabolism in AM from CD4-depleted mice demonstrated reduced LT synthesis (LTC4: 66.9 +/- 8%; LTB4 61.4 +/- 6.2% control). The decrease in 5-LO metabolism was associated with reduced FLAP (30.1 +/- 14.5% of control) and 5-LO expression (49 +/- 13.7% of control). This defect in AM 5-LO metabolism in CD4-depleted mice was further associated with reduced LTC4 levels in bronchoalveolar lavage (BAL) fluid. In summary, factors secreted constitutively by lung lymphocytes, in particular CD4 cells, contribute to the increased 5-LO metabolism in AM.

5-Lipoxygenase-Activating Proteins↗
PubMedDate not supplied

Role of cytokines in T cell immunity to a pulmonary Cryptococcus neoformans infection.

The objective of these studies was to present an overview of our studies of the cytokine network and cellular interactions responsible for the T-cell-mediated inflammatory response in the lungs following infection by Cryptococcus neoformans. In a resistant strain of mice, moderately virulent cryptococci were progressively cleared from the lungs after week 1. Characterization of mitogen-induced cytokine production demonstrated that the T cells in the lungs during the first 3 weeks of infection resembled Th0 rather than Th1 cells. In addition, the production of IL-10 (by mitogen-stimulated leukocytes) could promote an increase in the ratio of Th2:Th1 cytokines in short-term in vitro cultures. In vivo, there were increases in the alveolar levels of tumor necrosis factor-alpha and IL-6 at weeks 1-3 and the chemokines monocyte chemoattractant protein-1 at weeks 1-2 followed by macrophage inflammatory protein-1 alpha and ENA-78 at week 3. Overall, the pulmonary inflammatory response to C. neoformans evolved over 5 weeks from granulocytic to mononuclear, suggesting a maturation to a Th1-type response by week 5.

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