Biomedical subjects

C Olive

Publications and source records attributed to C Olive.

At least 37 records · Page 2Linked to original sources

PubMed1995

T cell receptor usage in autoimmune disease.

Activated T-cells are believed to play a critical role in the pathogenesis of autoimmune disease. In experimental allergic encephalomyelitis (EAE), an animal model resembling human multiple sclerosis (MS), there is evidence that T cells reactive to myelin basic protein mediate an inflammatory response within the central nervous system leading to demyelination. Furthermore, encephalitogenic T cells express TCR with highly restricted V gene usage and consequently specific forms of immunotherapy directed against V gene products have been successful in preventing and treating EAE. These findings prompted studies into the analysis of TCR repertoire expression in human autoimmune diseases in an attempt to identify the TCR usage of autoreactive and potentially pathogenic T cells. However, this has proved difficult as the autoantigens that drive the T cell response in most human autoimmune disorders are unknown. This review examines the data that have accumulated over the past few years on TCR usage in human autoimmune diseases and is focused largely on rheumatoid arthritis and MS.

Autoimmune Diseases↗

PubMed1994

Glutathione S-conjugate transport by cultured human cells.

Elimination of the products of xenobiotic metabolism is an important step in cellular detoxification and involves a specific transport system or "export pump". ATP-dependent transport of glutathione S-conjugates has previously been demonstrated in a variety of tissues, mainly from rat. However, the characteristics of this pump have not been fully explored in human cells. This study investigated transport of a glutathione S-conjugate, 2,4-dinitrophenyl glutathione (GS-DNP), by a variety of cultured human cell lines. GS-DNP was generated intracellularly after treatment of cells with 1-chloro-2,4-dinitrobenzene and subsequent transport of the conjugate into the extracellular medium was measured spectrophotometrically at 340 nm. Calculation of the initial transport rates at 37 degrees C revealed considerable variation in GS-DNP secretion between cell lines which was statistically significant in some cases. A 2-fold increase in GS-DNP efflux was observed between Jurkat and HL-60 cells (11.360 +/- 3.893 vs. 5.662 +/- 2.263 nmol/10(6) cells/h, P < 0.007). The highest rate of transport was found in HepG2 cells (14.171 +/- 4.790 nmol/10(6) cells/h) whereas the 5637 cell line had the lowest level with a transport rate of 1.475 +/- 0.631 nmol/10(6) cells/h. For each cell line, transport of GS-DNP was almost totally inhibited or markedly reduced on ice. Pre-incubation of cells at 42 degrees C also lowered the initial transport rates compared with cells maintained at 37 degrees C but these were not significantly different except in the case of HeLa cells. ATP levels ranged from 30.5 to 89.3 nmol/mg protein and there was variation in the glutathione content and glutathione S-transferase activities of the cells. This report demonstrates firstly that transport of glutathione conjugates is a feature of many cell types in vitro and secondly that the basal levels of GS-DNP secretion vary significantly between human cells.

Adenosine Triphosphate↗

PubMed1994

Persistence of gamma/delta T cell oligoclonality in the peripheral blood of rheumatoid arthritis patients.

The peripheral blood of patients with rheumatoid arthritis (RA) contains oligoclonal gamma/delta T cell populations which may contribute to the pathogenesis of the disease. To investigate whether there is persistent gamma/delta T cell oligoclonality in RA peripheral blood, we screened polymerase chain reaction-amplified T cell receptor (TCR) cDNA, derived from peripheral blood mononuclear cells (PBMC) of four RA patients, with sequence specific oligonucleotides (SSO). The SSO used were specific for TCR variable (V) delta 1, V delta 2 and V gamma 9 transcripts comprising V-joining (J) junctions found over-represented in PBMC of the same RA patients, when bled up to 3 years previously. The dominant transcripts were expressed in the new PBMC samples, although in most cases at a lower frequency than was originally detected. In one patient there was almost 100% oligoclonality of V gamma 9-(N)-J gamma 2 junctional region sequences among the V gamma 9 cDNA clones, progressing from 55% oligoclonality in 15 months. These results indicate the persistence of clonally expanded gamma/delta T cells in the peripheral blood of RA patients. Whether this reflects continual endogenous or exogenous antigenic stimulation remains to be investigated. The findings presented in this report may have important therapeutic implications in view of the potential for immuno-intervention for the treatment of human autoimmune disorders, like RA.

Arthritis, Rheumatoid↗

PubMed1994

Restricted junctional diversity of T cell receptor delta gene rearrangements expressed in systemic lupus erythematosus (SLE) patients.

SLE is an autoimmune connective tissue disorder affecting multiple organs, in which T cells may play a central role. This study investigated T cell receptor (TCR) gamma/delta repertoire expression in peripheral blood mononuclear cells (PBMC) of SLE patients and healthy individuals using variable (V) gene family-specific polymerase chain reaction (PCR) amplification of TCR cDNA. The expressed V gamma repertoires were diverse in SLE and control PBMC, although V gamma IV gene rearrangements were barely detectable or not expressed in some patients. In contrast, delta chain expression was limited in all SLE patients, with delta transcripts rearranged primarily to the V delta 1 and V delta 2 genes, as opposed to control PBMC, in which all six V delta genes were detected. To assess the clonality of TCR populations, cDNA clones containing rearranged V delta 1, V delta 2 and V gamma 9 transcripts were sequenced from PBMC of both patients and controls. For controls, delta chain junctional region sequences showed extensive molecular heterogeneity, since virtually all 34 V delta 1 and 32 V delta 2 cDNA clones analysed were unique. A few V gamma 9 cDNA clones (3/21) had the same junctional region sequence motif (EVQEL) encoded largely by the V gamma 9 and joining (J) gamma P gene segments. Identical V gamma 9 junctional sequences were found in SLE patients that did not contain the EVQEL motif present in normal peripheral blood gamma/delta lymphocytes. Moreover, the predominant V delta 1-J delta -constant (C) delta and V delta 2-J delta-C delta gene rearrangements expressed in SLE PBMC showed restricted junctional diversity, but the oligoclonal delta transcripts were different in each patient. These findings suggest in vivo oligoclonal expansion of gamma/delta T cells in the periphery of SLE patients in response to a limited number of nominal ligands. Whether gamma/delta T cells contribute to the development of systemic autoimmunity remains to be investigated.

Adult↗

PubMed1992

Evidence for oligoclonality of T cell receptor delta chain transcripts expressed in rheumatoid arthritis patients.

The inflamed synovium of rheumatoid arthritis (RA) patients contains gamma/delta T cells which express predominantly T cell receptor (TcR) variable (V) delta 1 and V delta 2 chains. Such T cells may contribute to the pathogenesis of RA. To assess the extent of clonality among these T cell populations we sequenced the junctional regions of rearranged TcR V delta 1-C delta and V delta 2-C delta chain cDNA, after using the polymerase chain reaction (PCR) to amplify TcR delta chain transcripts isolated from synovial membrane mononuclear cells (SMC) of five RA patients. The sequences of these delta chain transcripts were compared with those found in peripheral blood mononuclear cells (PBMC) of the same patients and in PBMC of four healthy controls. In contrast to control PBMC, V delta 1 chain cDNA derived from PBMC of three patients showed a strong bias towards usage of the same V-joining (J) combination and junctional region sequences, although the specific sequences were unique in each patient. However, oligoclonality of the V delta 1 chain was less marked in SMC of two of these patients and absent in SMC of the other patients. For V delta 2, oligoclonality was detected in PBMC of two patients. In SMC of a single patient, a dominant V delta 2 transcript was detected that utilized the J delta 2 segment, which was rarely expressed in the normal TcR repertoire. These results indicate in vivo clonal expansion of V delta 1- and V delta 2-expressing gamma/delta T cells in the peripheral blood of RA patients and a synovial T cell infiltrate which consists largely of polyclonally expanded gamma/delta T cells, but shows clonal dominance in some patients. Our data strongly support a role for V delta 1+ and V delta 2+ gamma/delta T cells in the pathogenesis of RA, and, although the nature of the antigen(s) recognized by these cells remains elusive, this report suggests the potential involvement of antigen(s) specific for the V region and V-J junction.

Amino Acid Sequence↗

PubMed1992

Molecular characterization of the V gamma 9 T cell receptor repertoire expressed in patients with rheumatoid arthritis.

We have characterized the variable (V)gamma 9 T cell receptor (TcR) repertoire expressed in synovial membrane (SMC) and peripheral blood mononuclear cells (PBMC) of five rheumatoid arthritis (RA) patients. The experimental approach was to sequence the junctional regions of polymerase chain reaction (PCR)-amplified V gamma 9 transcripts; gamma chain sequences were compared with those found in normal PBMC. For normal PBMC, a large proportion of V gamma 9 transcripts used the joining (J)gamma P gene segment whereas a few used J gamma 2. Despite this restriction in J gamma usage, there was extensive junctional region diversity with a unique sequence observed in each transcript examined. In contrast to normal PBMC, J gamma usage of V gamma 9 transcripts in PBMC of two patients was skewed towards J gamma 2. This deviation in J gamma usage was more pronounced in SMC since all patients expressed V gamma 9 transcripts in SMC which predominantly used J gamma 2, as opposed to J gamma P in normal PBMC. Further, approximately 60% of V gamma 9 transcripts in PBMC of each of three patients had identical junctional region sequences, although the specific sequences were unique in each patient. For two of these patients the dominant transcript found in the PBMC was detected in the corresponding SMC at about 10% and 40%, respectively. Overall, our findings indicate that V gamma 9-bearing T cells in RA peripheral blood are largely derived from clonal expansion whereas in the synovium there is expression of a population of these cells that are mainly polyclonal. This may reflect in vivo expansion in response to a V gamma 9/J gamma 2 region-specific antigen. The data presented in this report suggest that V gamma 9+ T cells may play a role in the development of RA.

Amino Acid Sequence↗

PubMed1992

Variable gene usage of T cell receptor gamma- and delta-chain transcripts expressed in synovia and peripheral blood of patients with rheumatoid arthritis.

The synovial tissue and fluid of patients with rheumatoid arthritis (RA) contain activated T cells that probably have a central role in the disease process which leads to joint destruction. A subset of T cells, gamma delta T cells detected at the site of inflammation, may be important in the pathogenesis of the disease. This study investigated variable (V) gene usage of gamma delta T cell receptors (TcRs) expressed in synovia and peripheral blood of patients with RA by using the polymerase chain reaction (PCR) to amplify TcR gamma- and delta-chain transcripts. Most patients showed no restriction in V gamma gene usage since synovial mononuclear cells (SMC) expressed TcR gamma-chain transcripts which used the same set of V gamma genes as peripheral blood mononuclear cells (PBMC). In contrast, the majority of patients expressed a restricted SMC V delta-chain repertoire biased towards V delta 1, but V delta 2 mRNA transcripts were also detected, albeit at low levels in some patients. The TcR delta-chain repertoires of PBMC from healthy control subjects were also characterized. There was variation in the TcR delta-chain repertoires of PBMC from patients when compared with controls, particularly with respect to expression of V delta 4. V delta 4 mRNA transcripts were expressed in PBMC of only two of seven RA patients in contrast with eight of the nine controls (P = 0.03). These findings are compatible with reports that gamma delta T cells in the rheumatoid synovium are reactive to Mycobacterium tuberculosis and that response to M. tuberculosis is restricted to V gamma 9/V delta 2-bearing T cells, if a superantigen is involved in the pathogenesis of RA.

Arthritis, Rheumatoid↗

PubMed1991

Analysis of T cell receptor V alpha and V beta gene usage in synovia of patients with rheumatoid arthritis.

T cells are thought to play a fundamental role in the pathogenesis of rheumatoid arthritis (RA). Activated T cells expressing alpha/beta T cell receptor (Tcr) infiltrate the rheumatoid synovium and could potentially initiate a local inflammatory response directed against joint constituents. A Tcr repertoire with restricted heterogeneity may reflect a selective expansion of T cells reactive to a few antigenic determinants within the synovium. To determine whether predominant V alpha and/or V beta gene usage of the expressed alpha/beta Tcr repertoire is a feature of synovial T cells in patients with RA, the polymerase chain reaction (PCR) was used to amplify Tcr-alpha and Tcr-beta chain transcripts. The peripheral blood and synovia of five patients with adult RA were examined and no evidence of preferential use of 19 Tcr V alpha gene families was found. Similarly, most of the 18 Tcr V beta gene families could be detected in RA synovia although there were quantitative differences in Tcr V beta gene expression when compared to peripheral blood. This report shows that when the extremely sensitive assay of oligonucleotide hybridization of PCR amplified Tcr transcripts is used, permitting identification of specific V gene families, the alpha/beta Tcr repertoire in the rheumatoid synovium is more diverse than was previously thought. Therefore, in patients with RA of long duration, the synovial T cell response is most likely to be polyclonal.

Arthritis, Rheumatoid↗

PubMed1991

Fc gamma RII restriction fragment length polymorphism (RFLP): analysis in systemic lupus erythematosus and scleroderma and evidence of an alpha gene duplication.

The characteristic finding of high levels of circulating immune complexes in patients with the autoimmune connective tissue diseases systemic lupus erythematosus (SLE) or scleroderma has raised the possibility that these patients may have a primary defect in immune complex clearance. The Fc receptor for IgG (Fc gamma R) plays a central role in the phagocytosis of antibody complexes. We have analysed Fc gamma R (type II) RFLPs identified in TaqI- and MspI-restricted genomic DNA and found that their distribution in SLE and scleroderma did not differ significantly from controls. Hybridization with specific regions of the Fc gamma RII cDNA clone indicate that part of the Fc gamma RII alpha locus is duplicated in some individuals. A further Fc gamma RII gene has recently been identified (Fc gamma RII alpha'). This gene shows greater than 95% homology with Fc gamma RII alpha and may thus be the candidate gene for the apparent alpha duplication seen in some individuals. It is possible that an individual may possess one, two, three or four TaqI Fc gamma RII alpha/alpha' alleles, correlating with incidence and numerical heterogeneity in Fc gamma RII alpha and alpha'. The physiological effects of this numerical heterogeneity remain to be investigated.

Antigens, Differentiation↗

PubMed1990

A serum-free culture method for myeloma progenitors in vitro: proliferative and immunophenotypic characteristics.

Methods for forming multiple myeloma (MM) colonies are difficult because nonproliferative, but viable, plasma cells can survive for several weeks in culture and because MM cells tend to clump readily, forming pseudo-colonies. The present study describes a method for growing pure myeloma colonies in serum-free conditions in which genuine myeloma growth is unequivocally demonstrated. Growth was observed in 17 of 32 MM bone marrow samples. After a delay of 3-5 weeks, during which most cells died, Ig light-chain-restricted colonies emerged, expanded for approximately 3 weeks, and then showed no evidence of further proliferation. Cell doubling time was 8-10 days, and a significant number of cells in all cultures expressed Ki-67, having earlier lacked this nuclear proliferation antigen. In addition, colony formation was abrogated by irradiation, and two of eight cultures were successfully replated in 0.8% methylcellulose. Phenotypic analysis revealed a mixed population of plasma cells (RFD6+) and B-lymphocytes (CD19+, CAL-LA-), and cells were consistently Epstein-Barr virus negative. Culture of myeloma bone marrow by this serum-free method will allow appraisal of the role of various recombinant growth factors.

Antigens, Viral↗

PubMed1987

[Laser treatment of villous rectal tumors].

The treatment of villous rectal tumors with the Nd: YAG laser is characterized by its great effectiveness (almost 90% of complete eradication in our series of 100 cases), and by its great tolerance. It may be applied to all patients regardless of their condition. In case of running villous tumors, complete destruction is more difficult to obtain and the laser method must be weighed against the risks and advantages of radical surgery. The problems raised by frequent foci of adenocarcinoma, which characterize large villous lesions, is minimized by a strict therapeutic protocol: in fact, the foci are superficial in the majority of the cases and they do not decrease the percentage of complete destruction; in other cases, it is possible, by repeated histological controls, in case of persisting positive biopsies, to modify, in time, the choice of treatment.

Adenoma↗

PubMed1978

[Fibrorectosigmoidoscopy. Results of 476 cases (author's transl)].

A fibrorectosigmoidoscope, 60 cm in length has been systematically applied in the endoscopy unit to the exploration of the distal colon. Technical parameters have been analysed in 300 patients: --immediate enema preparation was satisfactory (95% of examinations), --tolerance was good (96% of examinations), --mean length of colon explored reached 48,5 cm, --mean length of duration reached 5,15 mn. Efficacy in the detection of colonic lesions was tested in 476 patients (symptomatic or asymptomatic). Tumoral lesions were detected in 105 patients, with a total of 125 adenomas and 31 cancers; 71 lesions were found in the area that could be explored by a rigid rectosigmoidoscope (0-19 cm) while 85 were beyond this limit (20-60 cm). The fibre endoscope explores a larger territory (rectum + sigmoid), resulting in increased efficacy in the detection of colonic lesions. It should therefore replace progressively the rigid instrument in spite of its higher cost.

Adenocarcinoma↗

PubMed1978

Flexible rectosigmoidoscopy in the detection of tumoral colonic lesions.

The fibrorectosigmoidocope Olympus TCF I S, has been systematically applied to the exploration of the distal colon (rectum and sigmoid) in patients with intestinal or digestive extra intestinal symptoms. In the first 300 patients the technical parameters of the method were tested: the fleet enema preparation was found excellent or satisfactory in 95% of examinations. The tolerance was good in 96% of examinations--the mean length of operation was 5.15 min--the mean length of colon examined was 48.5 cm, the distance of 50 cm being surpassed in 50% of patients. The efficacy in the detection of the lesions was tested in 476 patients. Tumoral colonic lesions were detected in 105 patients with a total of 125 adenomas and 31 cancers. In the area that could have been explored by a rigid rectosigmoidoscope (0-19 cm) we found 71 lesions (50 adenoma and 10 carcinoma), whereas beyond this limit (25-60 cm) 85 lesions (50 adenoma and 10 carcinoma).

Adenoma↗

PubMed1977