Clinical and experimental immunology
-
Clin. Exp. Immunol. · Aug 1998
Comparative StudyHuman lung cancer cell lines express cell membrane complement inhibitory proteins and are extremely resistant to complement-mediated lysis; a comparison with normal human respiratory epithelium in vitro, and an insight into mechanism(s) of resistance.
Human lung cancer expresses cell membrane complement inhibitory proteins (CIP). We investigated whether human lung cancer cell lines also express cell-membrane CIP molecules and whether the biology of CIP molecules in these cell lines differs from that of CIP in normal human respiratory epithelium in culture. The cell lines ChaGo K-1 and NCI-H596 were compared with normal human nasal epithelium in primary cultures in respect to the level of cell membrane CIP expression of membrane cofactor protein (MCP; CD46), decay-accelerating factor (DAF; CD55) and CD59, in respect to the level of cell resistance to complement-mediated lysis, and in respect to the contribution of cell membrane CIP to cell resistance against complement-mediated lysis. ⋯ We suggest that the biology of cell membrane CIP molecules in human lung cancer cell lines is different from that of CIP in normal respiratory epithelial cells. Human lung cancer cell lines are able to prevent significant complement activation upon its cell membrane and are therefore especially resistant to complement-mediated lysis. Complement resistance may serve this common and highly lethal human cancer as an escape mechanism from the body's immunosurveillance and prevent effective immunotherapy with tumour-specific MoAbs.
-
Clin. Exp. Immunol. · Aug 1997
Comparative StudyHuman mast cells expressing recombinant proteinase 3 (PR3) as substrate for clinical testing for anti-neutrophil cytoplasmic antibodies (ANCA).
We have expressed conformationally intact, enzymatically active recombinant PR3 in HMC-1 cells (HMC-1/PR3 cells) that is recognized by C-ANCA. Here we directly compared the clinical utility of C-ANCA testing by indirect immunofluorescence (IIF) using HMC-1/PR3 cell cytospin versus polymorphonuclear neutrophil (PMN) cytospin preparations and commercially available anti-PR3 ELISA kits. Two hundred sera were tested independently by three investigators: 101 previously determined to be C-ANCA-positive by routine clinical laboratory testing using standard IIF on PMN cytospins, and 99 control samples chosen primarily because they contained antibodies against other cytoplasmic target antigens. ⋯ IIF using HMC-1/PR3 cells was as sensitive as the most sensitive anti-PR3 ELISA (79.8% versus 80.7%, P = 0.739), and more sensitive than standard IIF C-ANCA testing using PMN cytospins (79.8% versus 75.2%, P = 0.025) or the anti-PR3 ELISA with the least false-positive test results (79.8% versus 63%, P < 0.01). These findings indicate that HMC-1/PR3 cells are a very sensitive antigen-specific substrate for clinical anti-PR3 ANCA testing which appears superior to standard C-ANCA testing using PMN cytospin substrates and anti-PR3 ELISA. Our results also suggest that in WG the C-ANCA fluorescence pattern is not caused by antibodies against target antigens other than PR3.
-
Clin. Exp. Immunol. · May 1996
ReviewSupplemental immune globulins in sepsis: a critical appraisal.
For 'the total population of patients with sepsis, sepsis syndrome or SIRS', the question of whether intravenous immune globulin (IVIG) reduces mortality is neither proved nor disproved. For the sepsis subgroups 'postoperative sepsis with a sepsis score more than 19' and 'endotoxaemic, early septic shock', a significant reduction in mortality by IVIG has been documented in a single, placebo-controlled, small trial of each subgroup; subsequent studies are needed for confirmation. ⋯ Postoperative APACHE II-score identification of high-risk cardiac surgery patients prone to sepsis and severe SIRS may represent one approach to optimize individual, early therapy. Applying this concept to immune globulin treatment in a pilot study, the administration of IgG-IVIG and IgGMA-IVIG yielded similar results.
-
Clin. Exp. Immunol. · Aug 1995
Randomized Controlled Trial Comparative Study Clinical TrialComparison of two types of intravenous immunoglobulins in the treatment of neonatal sepsis.
In a prospective double-blind study, standard intravenous immunoglobulin (IVIG) was compared with an IgM-enriched IVIG in the treatment of neonatal sepsis. The two treatment groups were also compared with matched controls. One hundred and thirty babies (65 in each group) ranging from 0 to 24 days old, 480 to 4200 g in weight and born between 24 and 42 weeks of gestation who had, or were suspected of having, sepsis were given either standard IVIG or IgM-enriched IVIG (250 mg/kg per day) for 4 days in addition to supportive and antibiotic therapy. ⋯ Mortality from infection in 'culture proven sepsis' was 3/44 (6.8%) in the IgM-enriched IVIG group, 6/42 (14.2%) in the standard IVIG group, and 11/43 (25.5%) in the control group (P = 0.017, IgM versus control, P = 0.19 standard IVIG versus control). There was no statistical difference in the outcome between the two immunoglobulin therapy groups (P = 0.25). The study indicates that IVIG improves outcome in neonatal sepsis when used as an adjunct to supportive and antibiotic therapy, but larger studies are required to confirm this.
-
Clin. Exp. Immunol. · Feb 1995
The immunosuppressive drug thalidomide induces T helper cell type 2 (Th2) and concomitantly inhibits Th1 cytokine production in mitogen- and antigen-stimulated human peripheral blood mononuclear cell cultures.
Thalidomide is an effective immunomodulatory drug in man, but its mechanism of action remains unclear. We hypothesized that, in addition to its reported inhibitory effects on production of monocyte-derived tumour necrosis factor-alpha (TNF-alpha), thalidomide might be effective at the level of Th immunoregulation. In a comparative study with the immunosuppressant cyclosporin A, we have demonstrated a potent and specific effect of thalidomide on cytokine production relating to the distinct Th1 and Th2 subsets. ⋯ Time course data from thalidomide-treated cultures revealed that the augmented IL-4 production diminished as the culture time increased, whereas IFN-gamma production was significantly increased. This response might be due to activation-induced apoptosis of Th2 cells or the induction of Th2 cell anergy, in the continued presence of stimulating agents, with the emergence of IFN-gamma-secreting Th1 cells when Th2 antagonism declines. The effects of thalidomide and related compounds may enhance our understanding of the mechanisms of T helper cell selection, offer the possibility of controlled therapeutic switching between Th1 and Th2 responses, and may lead to a rational approach for the treatment of some T cell-mediated immunological disorders.