Human airway epithelial cells stimulate T-lymphocyte lck and fyn tyrosine kinase

Previous studies have shown that human airway epithelial cells (AEC) can stimulate allogeneic peripheral blood T-lymphocyte (PBT) proliferation. We now sought to determine which AEC surface molecule/T-cell coreceptors are involved in this process. AEC-induced PBT proliferation was inhibited by 25 microM genestein or herbamycin A (0.9 and 1.8 microM), both tyrosine kinase inhibitors. Anti-phosphotyrosine immunoblots performed on PBT lysates after coculture with AEC demonstrated phosphorylation of 56kD and 60kD bands. To determine whether CD3 associated p59fyn, or CD4 and CD8 associated p56lck phosphotyrosine kinases (PTK) were involved, we assayed kinase activity in lymphocyte lysates immunoprecipitated with anti-p56lck and p59fyn mAbs. PBT cells or murine T-cell line transfectants expressing human CD4 (3G4) or human CD8alpha (3G8) were cocultured with AEC or A549, an alveolar-like cell line lacking class II Ag expression. After A549 or AEC coculture, p56lck activity in PB T-cells peaked at 2 min whereas p59fyn kinase activity continued to rise at 8 min. AEC (expressing class II Ags) stimulate PTK activity in both 3G8 and 3G4 cells. A549 stimulated p56lck in 3G8, but not in 3G4 cells. This activation of p56lck was not blocked by preincubation of A549 with anti-class I or anti-CD1d mAbs. An antibody generated in our laboratory, which recognizes an epithelial specific surface molecule (mAb L12) and which blocks AEC driven PBT proliferation, was shown to block PTK activity of peripheral blood T-cell lysates, though not of 3G8 lysates. These studies suggest that AEC are capable of stimulating CD4 and CD8 associated lck and CD3 associated fyn kinases through class II dependent and independent pathways.

A patient with antineutrophil cytoplasmic antibody-negative pulmonary capillaritis and circulating primed neutrophils

We describe an antineutrophil cytoplasmic antibody-negative patient with capillaritis, acute respiratory failure, and primed neutrophils circulating systemically. Thoracoscopic lung biopsy showed capillary destruction, with neutrophils infiltrating the lung interstitium and air spaces but no alveolar damage or hemorrhage. We suggest that this atypical, limited form of pulmonary injury may occur when circulating neutrophils are primed, but, in the absence of an activating factor, not fully activated.

In vitro glycolysis of whole blood can detect primed neutrophils in septic ICU patients

The purpose of this study was to develop a bedside assay based on the in vitro glycolysis of a whole blood sample that could detect primed neutrophils (PMNs). A mathematical index of the PMN response to exogenous stimulation with phorbol myristate 13-acetate (PMA), called the Delta value, was derived by comparing the increase in glycolysis for paired blood samples with and without PMA to that expected from normal subjects. Delta values for systemic inflammatory response syndrome/sepsis patients (9.09 +/- 7.61) (N = 36) were significantly higher than normal controls (2.02 +/- 1.76) (N = 51), nonsepsis ICU patients (3.81 +/- 2.80) (N = 14) and patients in septic shock (2.33 +/- 3.04) (N = 10) (p < .05). Delta values were consistently reflected in parallel measurements of increased reactive oxygen species production by neutrophils detected cytofluorometrically. PMN priming can be simply and rapidly detected by an assay based on the numbers of PMNs and erythrocytes and the measured rates of in vitro glycolysis of paired whole blood samples with and without PMA.

In vivo detection of a novel macrophage-derived protein involved in the regulation of nasal mucus-like glycoconjugate secretion

BACKGROUND

We recently described a novel 68 kd mucus secretagogue (MMS-68) derived from human monocytes, pulmonary macrophages, and a macrophage hybridoma, clone 63. We detected MMS-68 in monocyte culture supernatants from patients with steroid-dependent asthma and in bronchoalveolar lavage fluid from patients with chronic bronchitis by antigen capture ELISA and in normal lung tissue by immunohistochemistry.

METHODS

To determine a role for MMS-68 in the regulation of nasal mucus, we labeled human nasal turbinates with tritiated glucosamine and assayed for the ability of the previously purified MMS-68 (stock solution) to induce mucus-like glycoconjugate release (MLGC). We also performed immunohistochemistry stains with an anti-MMS-68 antibody (1-D-10) on frozen sections (n = 5) of nasal turbinates from patients with allergic and nonallergic rhinitis who were undergoing rhinoplasty and measured MMS-68 levels in nasal lavages from patients who were undergoing topical nasal histamine or methacholine challenge.

RESULTS

MMS-68 is a potent nasal MLGC secretagogue causing a dose-dependent increase in MLGC release in vitro. Staining revealed a subepithelial distribution for MMS-68. Antigen capture ELISA of nasal lavages demonstrated mean MMS-68 levels from saline control challenge of 0.9 +/- 0.5 micrograms MMS-68 per milligram of protein (n = 5), 8.6 +/- 1.4 micrograms MMS-68 per milligram of protein from histamine challenge and 20.7 +/- 2.3 micrograms MMS-68 per milligram of protein (n = 5) after methacholine challenge.

CONCLUSION

Taken together these data suggest that MMS-68 may play a role in the normal regulation of mucus secretion.

Selective regulation of cytokine secretion by hydroxychloroquine: inhibition of interleukin 1 alpha (IL-1-alpha) and IL-6 in human monocytes and T cells

To study the effect of hydroxychloroquine on cytokine production by monocytes and T cells, cells were pretreated with varying concentrations of hydroxychloroquine and stimulated with lipopolysaccharide (monocytes), phytohemagglutinin or anti-CD-3 monoclonal antibodies (T cells). Interleukin 1 alpha (IL-1-alpha), IL-6 and tumor necrosis factor alpha (TNF-alpha) production were measured from the stimulated monocytes and IL-2, IL-4 and gamma interferon (IFN-gamma) were measured from the stimulated T cells. Hydroxychloroquine inhibited production of IL-1-alpha (monocytes) and IL-6 (T cells and monocytes). In contrast IL-2, IL-4, TNF-alpha and IFN-gamma production were not affected. Preferential inhibition of IL-1-alpha production by monocytes and IL-6 production by T cells and monocytes may contribute to its antiinflammatory effect in autoimmune diseases.

Inhibition of human immunodeficiency virus type 1 replication by hydroxychloroquine in T cells and monocytes

Chloroquine and its analogue hydroxychloroquine (HCQ) have been shown to inhibit a variety of viral infections including influenza and adenovirus through blockade of viral entry via inhibition of endosomal acidification. We have extended these observations to human immunodeficiency virus type 1 (HIV-1) infection utilizing primary T cells and monocytes, a T cell line (CEM), and a monocytic cell line (U-937). HCQ inhibited HIV-1 replication (> 75%), as measured by reverse transcriptase activity, in the primary T cells and monocytes as well as the T cell and monocytic cell lines. HCQ itself had no anti-reverse transcriptase activity and was not toxic to the cells at concentrations inhibitory to viral replication. Intracytoplasmic staining with an anti-p24 antibody, 24 h after infection, revealed the presence of intracytoplasmic virus, suggesting that the drug does not block viral entry. The production of steady-state HIV-1 mRNA was not affected by HCQ in that comparable levels of HIV-1 mRNA could be detected by Northern blot analysis and by in situ hybridization in both the HCQ-treated and untreated cells. However, HCQ does appear to affect production of infectious HIV-1 virions because viral isolates from HCQ-treated cells could not infect target CEM cells. These data suggest that HCQ may be useful adjunctive therapy in the treatment of HIV-1 infection.

In vivo detection of a novel macrophage-derived protein involved in the regulation of mucus-like glycoconjugate secretion

We previously described a novel 68,000 D macrophage-derived protein (MMS-68) that can stimulate mucus-like glycoconjugate (MLGC) secretion from cultured human airways, respiratory epithelial cells, and the ishikawa adenocarcinoma cell line. To better characterize this mucus secretagogue, we generated monoclonal antibodies against MMS-68 by injecting crushed SDS-PAGE gel slices containing this protein into Balb-C mice followed by fusion with SP2/0, a nonsecreting mouse myeloma cell line. A panel of monoclonal antibodies was produced that identified the 68,000 D MMS by immunoblot analysis and immunoprecipitation. The monoclonal antibodies detected MMS-68 in normal peripheral blood monocytes and pulmonary macrophages by cytofluorographic analysis and in human airways as determined by immunohistochemistry. Utilizing the monoclonal antibodies, an antigen-capture ELISA assay was developed. Statistically significant elevations in levels of MMS-68 were detected in bronchoalveolar lavage fluid (BALF) of chronic bronchitic subjects and cigarette smokers and in monocyte culture supernatants from steroid-dependent asthmatic patients compared to normal control subjects. The 68,000 D MMS is a potent secretagogue and may play an important role in the regulation of mucus secretion, especially in chronic bronchitis and steroid-dependent asthma.

Evidence for accessory cell function by class II MHC antigen-expressing airway epithelial cells

Expression of major histocompatibility complex (MHC) class II antigens is a requirement for accessory cell function in antigen presentation. Recent reports have demonstrated the presence of class II antigens on human bronchial epithelial cells. In the present study, immunohistochemical staining revealed HLA-DR on human airway epithelial cells obtained from two different mucosal sites (lobar bronchus and nasal turbinates). To determine whether airway epithelial cells bear functional class II molecules that allow for their cognate interaction with T lymphocytes, cells isolated from these sites were used in mixed lymphocyte cultures (MLR), as an in vitro model of accessory cell function. Freshly isolated cells (11 bronchi/3 turbinates) stimulated allogeneic T lymphocytes (stimulation index [S.I.] = 9.3 [mean]; P less than 0.001 compared to T cells alone). In order to assess the potential role of contaminating conventional accessory cells, bronchial epithelial cell isolates were first preincubated in a serum-free, growth factor-supplemented medium that functionally eliminates potential non-epithelial stimulators prior to MLR culture. Conventional accessory cell-depleted epithelial cells were still capable of stimulating allogenic T lymphocytes in 18 of 23 MLR cultures (S.I. = 5.5 [mean]; P less than 0.0005 compared to T cells alone). The addition of an anti-class II monoclonal antibody (VG2.2) at the onset of culture completely inhibited the MLR response (n = 10). No shift in the CD4+/CD8+ ratio was detected between lymphocytes harvested from airway epithelial cell MLR (1.42 +/- 1.29) and the ratio from T lymphocytes cultured alone (1.3 +/- 0.75), suggesting that both CD4+ and CD8+ T lymphocytes were proliferating in response to stimulation from alloepitopes recognized on airway epithelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)