摘要:

SummaryA panel of eight cell lines has been derived from colon carcinomas. These cell lines have both been characterized according to standard criteria of growth rate, response to mitogens (epidermal growth factor and basic fibroblast growth factor), xenograft growth and growth in soft agar, and according to the ability of the cells to express epitopes known to be expressed by cells in the normal intestinal mucosa. The expression of epitopes present in columnar (absorptive) cells has been assessed using a panel of monoclonal antibodies to brush border peptidases and disaccharidases, villin and brush border‐specific peptides. Goblet cell epitopes have been determined by monoclonal antibodies to mucin and carcinoembryonic antigen. An antibody to chromogranin was used to identify endocrine cells. Using these antibodies we found that all the cell lines reacted with at least one of the antibodies to columnar cells. Similarly, varying proportions of cells in six of the eight cell lines stained with antibodies to mucin. None of the cells expressed chromogranin. Expression of a differentiated colonic phenotype, as measured from antibody staining, did not correlate with measurements of malignancy, such as the ability of the cells to grow in soft agar or as xenografts. Similarly, there was no correlation between retention of a colonic phenotype and the initial pathological stage of the tumour from which the cell lines were derived.

ISSN:0004-945X    

DOI:10.1038/icb.1992.30

出版商:Blackwell Publishing Ltd    

年代:2017

数据来源: WILEY

摘要:

SummaryThe temporal patterns of synthesis of prostaglandin (PG)E2and PGI2by organ‐cultured fetal thymic lobes and the cell population(s) responsible for synthesis of such products within the murine fetal thymus have been investigated. Embryonic day 14 thymic lobes were organ‐cultured in defined media for 14 days and the media were collected every 24 h and replaced with fresh media. Collected media were processed for quantitation of either PGE2or PGI2. Lobes were also cultured in 2′‐deoxyguanosine (1.35 mmol/L) to produce an enriched non‐lymphoid population. The per cent cyclooxygenase‐positive cells within non‐lymphoid cell‐enriched lobes as well as the capacity of such lobes to synthesize either PGE2or PGI2were determined and compared with that of intact thymic lobes. Results demonstrate that fetal thymic lobes,in vitro, differentially synthesize PGI2and synthesize PGE2at a constant rate. Moreover, lobes enriched for non‐lymphoid cells contain a greater percentage of cyclooxygenase‐positive cells and synthesize increased amounts of eicosanoids per 104cells compared with controls.

ISSN:0004-945X    

DOI:10.1038/icb.1992.31

出版商:Blackwell Publishing Ltd    

年代:2017

数据来源: WILEY

摘要:

SummaryRestriction length polymorphisms in the variable and constant regions of the T cell receptor α‐chain were examined in 42 Caucasians, 29 Maoris and 27 Pacific Islanders. Southern blots of Tag I digested DNA were hybridized with the T cell receptor α‐chain probe pY14. Our results confirm that a 1.4 kb T cell receptor α chain‐Tag 1 band is allelic to a 0.5 kb band. A significant difference in the frequency of the 1.4 and 0.5 kb alleles of the variable region of the α‐chain was detected in Caucasians when compared with Maoris or Pacific Islanders (P<0.0001). No differences in the frequency of the 2.0 and 7.0 kb alleles of the constant region gene were detected between any of the racial groups. These data may be relevant to ethnic differences in susceptibility to immune disorders.

ISSN:0004-945X    

DOI:10.1038/icb.1992.32

出版商:Blackwell Publishing Ltd    

年代:2017

数据来源: WILEY

摘要:

SummaryPrevious experiments have shown that whereas a secondaryin vitroKunjin‐immune cytotoxic T (Tc) cell population lysed equally well targets infected with either native flavivirus or a recombinant vaccinia virus expressing the immunodominant determinant, primaryin vivoKunjinimmune Tc cells were able to lyse only the recombinant vaccinia virus‐infected targets. Using CD8 blockade to assess the avidity of T cell‐target interaction, recombinant‐infected targets express antigen more efficiently than native flavivirus infected targets and secondaryin vitroKunjin‐immune Tc cells have a higher avidity for targets than do primaryin vivoKunjin‐immune Tc cells. Secondaryin vivoinfluenza‐immune Tc cells are also of higher avidity than primaryin vivoinfluenza‐immune Tc cells. Thus, a restimulated memory Tc cell population interacts with targets with greater avidity than does a recently activated naive population.

ISSN:0004-945X    

DOI:10.1038/icb.1992.33

出版商:Blackwell Publishing Ltd    

年代:2017

数据来源: WILEY

摘要:

SummaryThe effect of intra‐erythrocytic development of thePlasmodium falciparumparasite on local deformability of human erythrocyte membranes was studied by aspiration of cells into 0.56 μm diameter pores in polycarbonate filters and examination, after fixing, with a scanning electron microscope. As the aspiration pressure increased, the erythrocyte membrane was extruded into the filter pores. The pressure dependence of the protrusion length and the minimum pressure required to produce any deformation provided measures of the membrane shear and the bending moduli, respectively. At the trophozoite and, to a greater extent, schizont stage of development, host cell membrane deformability was significantly decreased. There was no appreciable difference between uninfected and ring‐infected erythrocytes.

ISSN:0004-945X    

DOI:10.1038/icb.1992.34

出版商:Blackwell Publishing Ltd    

年代:2017

数据来源: WILEY

摘要:

SummaryPeripheral blood mononuclear cells (PBM) obtained from leprosy patients and healthy controls were cultured withMycobacterium lepraeand the control antigens, BCG and SKSD. Parallel cultures were supplemented with additional interleukin‐2 (IL‐2). On the basis of the level of response toM. leprae, leprosy patients could be divided into low, intermediate and high responders. The addition of IL‐2 resulted in enhanced proliferation to antigen only by cells from intermediate responders. This effect was neither antigen specific nor was it confined to cells from leprosy patients. When limiting dilution analyses were performed on cells from 26 patients across the leprosy spectrum, noM. leprae‐reactive lymphocytes were detected in cells from subjects with lepromatous disease. The precursor frequency for cultures containingM. lepraeplus IL‐2 was no greater than that of cultures containing IL‐2 alone, thereby excluding the possibility of clonal anergy reversible with IL‐2. This was observed in both untreated patients and those on long‐term treatment, which made sequestration of antigen‐reactive cells within leprosy lesions an unlikely explanation. On the other hand,M. leprae‐reactive lymphocytes were detected in patients with tuberculoid and borderline tuberculoid disease and in two subjects with borderline lepromatous leprosy in type I reversal reaction. IL‐2 reactive cells were detected in all patients regardless of clinical classification. Three 'suppressor’curves were obtained but were not confined to cells from lepromatous patients. Taken together, these findings suggest that the non‐responsiveness toM. lepraecharacteristic of the great majority of multibacillary patients is due to an absence of antigen‐sensitive T cells.

ISSN:0004-945X    

DOI:10.1038/icb.1992.35

出版商:Blackwell Publishing Ltd    

年代:2017

数据来源: WILEY

摘要:

Book reviewed in this articles:ORGAN‐SPECIFIC AUTOIMMUNITYBy P. E. Bigazzi, G. Wick and K. Wicher.HEMATOPOIETIC GROWTH FACTORS IN CLINICAL APPLICATIONSBy R. Mertelsmann and F. Herrmann.LYMPHOKINES AND INTERLEUKINSMaureen M. Dawson, Allen and Unwin, 1991.

ISSN:0004-945X    

DOI:10.1038/icb.1992.36

出版商:Blackwell Publishing Ltd    

年代:2017

数据来源: WILEY