Cytogenetic analyses of a murine carcinoma cell line and six metastatic derivatives with different degrees of radioresistability.

We reported that a murine carcinoma (DEN3) an its six pulmonary metastases (M2, M4C, M4D, M4E, M4F, and M6) exhibited different degrees of radioresistability (In Vitro Cell. Dev. Biol.26:222-228; 1990). While the M2, M4C, M4E, and M4F cultured cells survived up to 2.5 Gy, the cells of DEN3 and M6 tolerated up to 5.0 Gy, and the M4D cells could withstand up to 10.0 Gy of X-irradiation. In the present investigation, the cytogenetic features of these cell lines were examined: (a) to determine the degree of cytogenetic heterogeneity among these cell lines, and (b) to investigate whether any association between the cytogenetic anomaly and the degree of radioresistability could be established. Heterogeneous cytogenetic aberrations were detected in all of the above lines. Karyotype analysis of the M4D and M6 cell lines displayed both numerical and structural abnormalities. The gain and loss of chromosomal copies were observed. Structural aberrations, such as translocation and deletion appeared in both cell lines. However, correlation between the cytogenetic abnormality and the degree of radioresistability was not demonstrated except for a dramatic reduction in one or more copies of the X-chromosome that occurred in 86% and 93% of the M6 and M4D cells, respectively. The results suggest heterogeneous cytogenetic aberrations among these cell lines and a possible association between the loss of X-chromosome and radioresistability of these tumor cells.

Bronchoalveolar lavage findings in cystic fibrosis patients with stable, clinically mild lung disease suggest ongoing infection and inflammation.

To determine the extent of airway infection and inflammation in adolescents and adults with cystic fibrosis (CF) who have mild lung disease and are without symptoms of active infection, we performed bronchoalveolar lavage (BAL) on 18 CF patients > or = 12 yr of age who were stable, appeared clinically well, and had mean (+/- SEM) FEV1 of 79 +/- 4% of predicted. We quantitated the bacteria, inflammatory cells, immunoglobulins, and mediators of inflammatory tissue damage in the epithelial lining fluid (ELF) of these patients and in 23 healthy control subjects. All CF patients were found to be infected with Pseudomonas aeruginosa, Staphylococcus aureus, and/or Haemophilus influenzae; no organisms were isolated from the control subjects. The mean number of cells in the ELF was 14 times greater in the CF patients than in the control subjects. Neutrophils constituted 57% of the recovered cells in the CF patients versus 3% in the control subjects, and their concentration was 380 times greater in the CF patients versus the control subjects. IgG, IgA, and IgM were 2.5 to 6 times greater in CF ELF versus that of control subjects. Abundant active elastase was present in the ELF of the CF patients (2.3 +/- 0.9 microM) despite threefold elevated levels of alpha 1-protease inhibitor (alpha 1-PI). No active elastase was detectable in the control subjects. alpha 1-PI was functional in CF as demonstrated by elevated elastase:alpha 1-PI complex (0.045 microM in CF versus 0.002 microM in control subjects). This active elastase caused proteolytic destruction of surface complement receptors on airway neutrophils in situ.(ABSTRACT TRUNCATED AT 250 WORDS)

Tissue-specific Fc gamma and complement receptor expression by alveolar macrophages determines relative importance of IgG and complement in promoting phagocytosis of Pseudomonas aeruginosa.

Because the expression of IgG Fc receptors and complement receptors on macrophages may vary in a tissue-specific manner, we used monoclonal antibodies and flow cytometry to define the expression and function of opsonin receptors on fresh normal and cystic fibrosis (CF) bronchoalveolar lavage (BAL) macrophages. Using flow cytometry to separately analyze individual types of cells, we then determined the relative contributions of IgG and complement to phagocytosis of Pseudomonas aeruginosa by fresh BAL cells, avoiding alterations in receptor expression due to in vitro purification or culturing techniques. Neither normal nor CF BAL macrophages express appreciable amounts of the complement receptors CR1, CR2, or CR3. These results were confirmed by immunohistochemical staining of fixed lung sections. BAL macrophages express a high-affinity IgG receptor, Fc gamma RI, that is not found on neutrophils (PMN). In contrast, chemoattractant-stimulated blood PMN express large amounts of CR1 and CR3 but do not express Fc gamma RI. These results correlate with phagocytosis assays, which show that phagocytosis by macrophages is enhanced by relatively low concentrations of IgG but that the addition of complement does not further increase their phagocytosis. In contrast, low concentrations of IgG alone do not promote phagocytosis by PMN, whereas addition of complement markedly enhances phagocytosis by PMN. These results may explain the previously reported sensitivity of macrophages rather than PMN to the "blocking" effects of anti-Pseudomonas antibodies from CF patients, and emphasize the pathologic significance of interference with IgG and complement mediated opsonization in the lung in CF.