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Biomedical subjects

J Even

Publications and source records attributed to J Even.

At least 37 records · Page 2Linked to original sources
PubMed1997

Identical T-cell receptor beta chain rearrangements are present in T cells infiltrating the jejunal mucosa of untreated celiac patients.

The intestinal mucosal lesion in celiac disease is characterized by a predominant T-cell infiltration of both epithelium and lamina propria. However, a restricted use of T-cell receptors (TCR) in T lymphocytes infiltrating the jejunal mucosa of celiac patients has not been reported. Based on an immunohistochemical survey of jejunal biopsies from a cohort of untreated celiac patients, we demonstrated a small but significant increase of V beta 8.1/2+ T cells in the lamina propria, but not in the epithelium nor in the peripheral blood. Sequence analysis indicated the existence of a variable degree of clonality of V beta 8+ T cells in the celiac mucosa. More importantly, the recurrence of identical CDR3 regions in some patients was also observed. The altered distribution of V beta 8+ T cells and the presence of identical CDR3 regions in celiac patients, but not in controls was independently confirmed by CDR3 size analysis in a further cohort of patients. These findings suggest that disease-specific variations of the TCRBV8 repertoire are present in the small intestinal mucosa of untreated celiac patients.

Amino Acid Sequence↗
PubMed1997

Clonality of tumor-infiltrating lymphocytes in human urinary bladder carcinoma.

The immune system has been implicated in the control of bladder tumor growth. To evaluate the clonality of bladder tumor-infiltrating T lymphocytes (TILs) in vivo, we studied the T-cell antigen receptor (TCR) repertoire in tumor biopsy specimens from 10 patients with transitional-cell carcinoma (TCC) of the bladder. Nine patients had a primary tumor, and one had a multifocal disease, consisting of two bladder tumors and three bilateral upper urinary tract sites of involvement. The following specimens from the nine patients with a primary tumor also were analyzed: a recurrent tumor from four patients, a metastatic lymph node from one patient, and peripheral blood from five patients. We used a high-resolution polymerase chain reaction (PCR) method to determine CDR3 (complementarity-determining region 3) size lengths of TCR beta-chain transcripts. Oligoclonal T-cell expansion was identified in all specimens, with a larger number of expanded clones in the tumors than in peripheral blood. Expanded clones were identified in several beta-chain variable region (BV) subfamilies and varied from one patient to the next and also in different specimens from the same patient. However, a number of clones with the same VJ combination and the same CDR3 size were identified in a given patient (in specimens collected either simultaneously or at different times), suggesting homogeneity in the immunogenic environment. Clonal T-cell expansion in patients with bladder cancer may reflect prolonged exposure of T lymphocytes to tumor antigens. Our findings provide a basis for functional studies to elucidate T lymphocyte-bladder tumor cell interactions.

Aged↗
PubMed1997

Full-scale 'naïve' human antibody repertoires assembled from VH and VL variable regions.

Very large 'naïve' human antibody repertoires have been obtained from RT-PCR cloned VH and VL variable regions. They are used as starting material for the assembly of medium sized combinatorial libraries or so called multicombinatorial libraries. In nonimmunized individuals immunoglobulin messenger RNAs are poorly expressed, which can be a serious limitation for cloning efficiency. To overcome this problem two complementary strategies have been used: a nonspecific polyclonal activation of B cells, and a secondary PCR amplification technique to ensure recovery of Ig messengers in large amount and without introducing any bias.

Antibodies↗
PubMed1996

Selection of T cells reactive against autologous B lymphoblastoid cells during chronic rheumatoid arthritis.

The repertoire and Ag specificity of T cells infiltrating inflamed joints from a chronic rheumatoid arthritis (RA) patient were studied in detail. Repertoire analysis demonstrated a reduced clonality of joint-infiltrating lymphocytes (JIL) as compared with patient's PBL, which was presumably due to an intra-articular expansion of T cell clones with recurrent TCR features. Strikingly, a large fraction of these JIL T cell clones, which were predominantly CD8+, proliferated in vitro when exposed to autologous B lymphoblastoid cells (BLC), unlike randomly chosen PBL clones derived from the same patient. This proliferative response was HLA-restricted, which confirmed a classical TCR-mediated recognition of BLC and was not observed against autologous PHA blasts, suggesting recognition of either EBV or B cell-specific Ags. Finally, a preliminary analysis of synovial lymphocytes derived from another chronic RA patient demonstrated a similar enrichment for T cells reactive against autologous BLC within JILs as compared with patient's PBLs. Taken together, these results, which suggest frequent expansions of autologous BLC-reactive T cells within inflamed joints of chronic RA patients, provide a basis for future studies evaluating the fine specificity and pathogenicity of these lymphocytes.

Adult↗
PubMed1996

T cell response to Epstein-Barr virus transactivators in chronic rheumatoid arthritis.

Rheumatoid arthritis is a multistep disorder associated with autoimmune features of yet unknown etiology. Implication of viruses such as Epstein-Barr virus (EBV) in rheumatoid arthritis pathogenesis has been suspected on the basis of several indirect observations, but thus far, a direct link between EBV and rheumatoid arthritis has not been provided. Here we show that a large fraction of T cells infiltrating affected joints from a patient with chronic rheumatoid arthritis recognizes two EBV transactivators (BZLF1 and BMLF1) in a major histocompatibility complex-restricted fashion. Responses to these EBV antigens by synovial lymphocytes from several other chronic rheumatoid arthritis patients were readily detectable. Thus these results suggest a direct contribution of EBV to chronic rheumatoid arthritis pathogenesis. They also demonstrate for the first time the occurrence of T cell responses against EBV transactivating factors, which might be central in the control of virus reactivation.

Animals↗
PubMed1996

Acute graft versus host disease due to T lymphocytes recognizing a single HLA-DPB1*0501 mismatch.

Analysis of a large number of unrelated bone marrow transplantations (BMT) has shown that HLA-DP incompatibility did not detectably influence the risk for acute graft-versus-host disease (aGVHD). Accordingly, it was proposed that HLA-DP determinants did not function as transplantation antigens in the same way as HLA-A, -B, or -DR. We have previously shown that HLA-DP (as well as HLA-A, -B, -DQ, or -DR)-specific T cells could be isolated from skin biopsies of patients who developed an aGVHD after semiallogeneic BMT. Nevertheless, whether a single HLA-DP mismatched allele could induce a detectable allo-specific reaction in vivo after BMT remained to be established. To directly address this issue we studied one patient who presented aGVHD after receiving purified CD34+ bone marrow (BM) cells from an unrelated donor with a single HLA-DP mismatch in the GVHD direction. To characterize the immunological events associated with GVHD, we analyzed the peripheral T cell repertoire, the T cell receptor Vbeta diversity, and the specificity of T cells invading a skin biopsy at the onset of GVHD. Our results demonstrated that a large fraction of skin-infiltrating lymphocytes, which expressed diverse T cell receptors, were reactive against this single HLA-DPB1 *0501 mismatch and consequently that a single HLA-DP mismatch between BM donor and recipient can activate a strong T cell response in vivo.

Alleles↗
PubMed1996

Restriction of the T-cell repertoire in tumor-infiltrating lymphocytes from nine patients with renal-cell carcinoma. Relevance of the CDR3 length analysis for the identification of in situ clonal T-cell expansions.

Renal-cell carcinoma (RCC) is one of the human cancers which respond best to immunotherapy. To better characterize the mechanism of the immune response in RCC, we analyzed the T-cell receptor (TCR) beta-chain repertoire in primary RCC, metastases and paired peripheral blood lymphocytes (PBL) from 9 patients. For 3 of these, we analyzed T cells recovered from normal kidney, or from tumor-involved lymph nodes as well as tumor-infiltrating lymphocytes (TIL) expanded in vitro for adoptive immunotherapy. The initial semi-quantitative RT-PCR method for definition of the Vbeta gene usage was not informative enough to distinguish intratumoral clonal T-cell expansions. In contrast, the length pattern analysis of the complementary determining regions 3 (CDR3) allowed oligoclonal T-cell populations to be detected in fresh TIL form the 9 patients with RCC. Furthermore, these oligoclonal TIL populations were not present in normal renal tissue, autologous PBL or tumor-involved lymph nodes. Different clonal T-cell expansions were identified in the primary tumor and in a pulmonary metastasis from the same patient. The detection of clonal T-cell populations observed in RCC suggests an in situ expansion in response to potential tumor antigens. This report provides an overall and accurate description of the T-cell repertoire in a significant number of samples from patients with RCC.

Carcinoma, Renal Cell↗
PubMed1996

The murine Fc-gamma (Fc gamma) receptor type II B1 is a tumorigenicity-enhancing factor in polyoma-virus-transformed 3T3 cells.

The murine receptor for the Fc portion of IgG is a molecule expressed by cells of the immune system. This study suggests the hypothesis that Fc gamma receptor type II B I (Fc gamma RIIB I) functions as a progression-enhancing factor when expressed ectopically on non-lymphoid tumor cells. It has been shown previously that BALB/c 3T3 cells transformed in vitro with polyoma virus (PyV) do not express Fc gamma RII but acquire the expression of this receptor following an in vivo passage in syngeneic mice. The specific Fc gamma RII transcript present in tumor cells was identified in this report as Fc gamma RIIB I (BI). In order to determine whether or not the ectopically expressed Fc gamma RII plays a role in the progression of these transformed cells, PyV-transformed 3T3 cells were transfected with BI-cDNA. The BI transfected cells were tested for their ability to form local tumors in syngeneic mice, as compared to transfected cells which express the co-transfecting neomycine resistance (neores) DNA alone or together with the lacZ gene. Fc gamma RIIB I expressors exhibited a significantly higher tumorigenic phenotype than FcR-negative controls, though both types of cells exhibited the same growth curve in vitro. The ability of Fc gamma RIIB I to act as a potentially tumorgenicity-enhancing factor was also demonstrated as Fc gamma RII was expressed by tumor cells, originating from inoculated Fc gamma RIIB I-transfected cells, or from inoculation of a mixture of receptor-positive and -negative cells. B I-expressing cells dominated the tumor-cell population over non-expressors. This dominance strengthened the hypothesis that FcR plays a role in tumor progression in vivo.

3T3 Cells↗
PubMed1995

T-cell repertoire diversity and clonal expansions in normal and clinical samples.

Improved polymerase chain reaction (PCR)-based methods now permit a more in-depth analysis of the repertoire of T cells recovered in biological samples from mice and humans. At a certain level of resolution, the diversity of the T-cell repertoire can be readily estimated and clonal expansions become easily detectable. As discussed here by Christophe Pannetier, Jos Even and Philippe Kourilsky, these improvements allow a better appreciation of the degree of reproducibility of immune responses, both in mice and humans, and should have a significant impact on clinical investigations.

Animals↗
PubMed1995

T-cell repertoires in healthy and diseased human tissues analysed by T-cell receptor beta-chain CDR3 size determination: evidence for oligoclonal expansions in tumours and inflammatory diseases.

Many examples of oligoclonal T-cell expansion in infiltrated diseased tissues have been reported. However, it remains to be established whether such observations can be generalized and to what extent oligoclonal patterns obtained after in vitro culture of T-cell infiltrates reflect in vivo situations. Using new high resolution analysis which requires no in vitro cellular expansion, we detected such oligoclonal T-cell expansions in 7/7 melanoma tumour biopsies, 3/3 biopsies of inflammatory skin during acute graft versus host disease (aGVHD) after allogeneic bone marrow transplantation (alloBMT) and 7/7 synovial membranes from patients with rheumatoid arthritis. Thus, oligoclonal T-cell expansions are readily observed when a sufficiently sensitive detection method is used, suggesting that similar expansions are the rule among T-cell infiltrates in different diseases. This observation and the monitoring of the in vivo evolution of such expansion during the course of the disease and during in vitro culture should have important clinical implications.

Acute Disease↗
PubMed1994

In vivo T-cell clonal amplification at time of acute graft-versus-host disease.

In a series of patients transplanted with HLA-matched allogeneic bone marrow grafts (alloBMT), we previously showed that a few T-cell receptor (TCR) V alpha and V beta gene segment transcripts were overexpressed in skin compared with blood at the time of acute graft-versus-host disease (aGVHD). Here, in one selected patient with overexpressed V beta 16 and V alpha 11 transcripts in skin, we analyzed the junctional variability of these transcripts in donor blood, patient blood, and skin collected at aGVHD onset. A unique junctional region sequence accounted for 81% of in frame V beta 16 transcripts (13 of 16) in skin and 59% (13 of 22) in patient blood. Similarly, two recurrent junctional region sequences were found in skin V alpha 11 transcripts, one accounting for 66% (21 of 32) and the other for 16% (5 of 32). These recurrences were also found in patient blood (36% and 15% of V alpha 11 transcripts, respectively). To extend our analysis, a polymerase chain reaction (PCR)-based method was used to precisely determine TCR beta transcript length in run-off reactions using uncloned bulk cDNA samples. All V beta-C beta PCR products analyzed in donor blood, as well as the majority of those analyzed in patient blood, included transcripts with highly diverse junctional region sizes. As expected from the sequence data, most V beta 16-C beta PCR products in skin and patient blood were of the same size (ie, same junctional region). In addition, V beta 3, V beta 5, and V beta 17 transcripts in skin were shown to display highly restricted size variability. The clonality of the V beta 16-C beta and V beta 17-C beta transcripts was further supported by the results of run-off reactions using 13 J beta specific primers. We have identified several recurrent TCR transcripts in skin, some of them also present in patient blood. These data support the view that several T-cell subpopulations are clonally expanded in vivo at the time of aGVHD onset in this case of related HLA-matched alloBMT.

Adult↗
PubMed1994

Oligoclonality of tumor-infiltrating lymphocytes from human melanomas.

A PCR-based method that determines VDJ junction size patterns in 24 human TCR V beta subfamilies was used to analyze T cells infiltrating sequential malignant melanoma biopsies for the presence of clonal expansions. Infiltrating T cell populations were found to present clonal expansions over a more or less complex polyclonal background. Two clones from a single patient were sequenced and detected in three different tumor sites (skin biopsies), whereas only one of them was also present in peripheral blood. Biopsies from this patient did not show major repertoire changes during in vivo IL-2 treatment. In contrast, in biopsies from a second patient, the expression of all the detected V beta subfamilies was increased and a larger number of clones expanded, probably as a result of therapy. A similar evolution was found among infiltrating T cells cultured in vitro from a third patient for several weeks in the presence of IL-2, where the largely polyclonal repertoire of fresh T cells (from invaded lymph nodes) was dramatically reduced to mainly clonal expansions in all V beta subfamilies detected. The high resolution method used here enables a rapid, comprehensive, qualitative, and semiquantitative description of the T cell repertoire of heterogeneous cell populations. Its use in conjunction with a functional analysis of clones detected within these populations should provide a better understanding of the evolution of the T cell repertoire among tumor-infiltrating lymphocytes during the progression of the disease and as a response to immunotherapy.

Base Sequence↗
PubMed1994

Evidence for T-cell clonal expansion in a patient with squamous cell carcinoma of the head and neck.

Squamous cell carcinomas of the head and neck (SCCHN) often contain a large mononuclear cell infiltrate, composed mainly of T-lymphocytes which could reflect an in situ immune reaction against the malignant SCCHN cells. We analyzed the molecular structure of the T-cell receptor (TCR) alpha and beta chains expressed by lymphocytes in the tumor, peripheral blood (PBMC), and in the peritumoral tissue in six cases of localized SCCHN. We first determined V alpha and V beta gene segment subfamily usage by polymerase chain reaction using a panel of V subfamily-specific oligonucleotide primers (V alpha 1-w29 and V beta 1-w24). An apparently unrestricted usage of V alpha or V beta gene segment subfamilies was observed for all three samples from the six cases examined. No major difference was observed in T-cell receptor repertoire expression of PBMC between SCCHN and healthy donors, making unlikely the expression of putative tumor-related superantigen(s) in these patients. Intersample comparisons for a given V alpha or V beta T-cell receptor specificity revealed some differences in V gene segment usage in tumor-infiltrating lymphocytes versus PBMC. A detailed analysis of these V segment subfamily specificities (cloning followed by sequencing and CDR3 size distribution analysis) in one patient revealed the presence of recurrent T-cell receptor transcripts (i.e., identical V-N-J sequences) in the tumor (e.g., 40%) and in PBMC (e.g., 75%). These results show that unique T-cell subpopulations are clonally amplified in SCCHN patients, possibly as a consequence of antigen-driven selection.

Adult↗
PubMed1992

Non-random features of the repertoire expressed by the members of one V kappa gene family and of the V-J recombination.

The 5' and 3' flanking sequences of 14 members of the V kappa Ox (VK 4/5) gene family of BALB/c mice have been established. The family was unusual in the number of bases between the codon for Pro 95 and the heptamer sequence; most members contained four but there were also examples of none. A conserved leader sequence was used to amplify the genomic DNA of rearranged genes in order to analyze the spleen B cell repertoire of non-immunized animals. The library contained many members with virtually identical sequences to one or other of the already known members of the family. In addition, there were repeats of other sequences, allowing the definition of 12 hitherto undefined members of the family. Only 3 out of 96 could have originated by gene conversion, or as artefacts of the amplification procedure, and only 2 were putative somatic mutants. The frequency of expression of different members of the V kappa Ox gene family was not random, and some germ-line genes were unrepresented in the library. The high frequency of V kappa Ox1-J kappa 5 is in line with the dominance of this combination in the oxazolone response. An analysis of the junctional segment showed that although in most cases the diversity was due to trimming, there were exceptions indicating de novo additions (N or P bases). The average number of bases trimmed from the V kappa and the J kappa segments was not the same. There was no correlation in the number of bases trimmed from V kappa or J kappa in each recombination. The implications of asymmetric trimming in terms of the mechanism of recombination are discussed.

Animals↗
PubMed1992

Phenotypic properties of 3T3 cells transformed in vitro with polyoma virus and passaged once in syngeneic animals.

Cloned BALB/c 3T3 cells transformed in vitro with polyoma virus (PyV) acquired a higher tumorigenicity phenotype after a single in vivo passage. Some of the in vivo passaged cells (CTC cells) exhibited also a higher metastatic phenotype than cells from the same clones that were maintained only in culture (C cells). A phenotypic comparison between CTC and C cells was performed. It was found that most CTC lines exhibited a higher binding to laminin compared to their clonal C cell ancestors. Some CTC cells were less sensitive to the cytotoxic effects of TNF-alpha than the corresponding C cells. CTC cells originating from tumors which appeared after a long latency period (late tumors) tended to express Fc gamma RII while CTC cells originating from tumors which appeared after a short latency period (early tumors) as well as the corresponding C cells tended not to express Fc gamma RII. The expression of a membrane epitope recognized by a monoclonal antibody expressing specificity towards PyV transformed cells, was down-regulated on late tumor cells compared to early tumor cells. Transfection of cloned PyV-transformed BALB/c 3T3 cells with the beta 1Fc gamma RII gene augmented the tumorigenicity and metastatic phenotype of the transfectants compared to control transfectants.

3T3 Cells↗