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P van den Elsen

Publications and source records attributed to P van den Elsen.

At least 19 recordsLinked to original sources
PubMed1998

Phenotypical and functional characterization of Herpesvirus saimiri-immortalized human major histocompatibility complex class II-deficient T lymphocytes.

CD8+ T lymphocytes from two unrelated cases of MHC class II deficiency were immortalized in vitro using Herpesvirus saimiri. In both cases, a lack of expression of surface MHC class II molecules was ascertained, whereas variable defects were shown for MHC class I, CD74 (invariant chain) and LAG-3 (an MHC class II ligand). The functional analysis of both H. saimiri-immortalized T-cell lines revealed the existence of a proliferation impairment in response to anti-CD3 but not to other surface or transmembrane stimuli. Further characterization of this functional defect indicated that it was not associated with impaired early activation events (like calcium flux) but, rather, with certain late events, like the induction of IL-2. H. saimiri-immortalized T cells may be valuable in studying the biological role of MHC class II molecules in activated human T cells.

Cell Transformation, Viral↗
PubMed1997

Mutation of RFXAP, a regulator of MHC class II genes, in primary MHC class II deficiency.

BACKGROUND: Major-histocompatibility-complex (MHC) class II deficiency is an autosomal recessive primary immunodeficiency disease in which MHC class II molecules are absent. It is a genetically heterogeneous disease of gene regulation resulting from defects in several transactivating genes that regulate the expression of MHC class II genes. The mutations responsible for MHC class II deficiency are classified according to complementation group (a group in which the phenotype remains uncorrected in pairwise fusions of cells). There are three known complementation groups (A, B, and C). METHODS: To elucidate the genetic defect in patients with MHC class II deficiency that was not classified genetically, we performed direct complementation assays with the three genes known to regulate the expression of MHC class II genes, CIITA, RFX5, and RFXAP, and the relevant mutations were identified in each patient. RESULTS: Mutations in the RFXAP gene were found in three patients from unrelated families, and the resulting defect was classified as belonging to a novel complementation group (D). Transfection with the wild-type RFXAP gene restored the expression of MHC class II molecules in the patients' cells. CONCLUSIONS: Mutations in a novel MHC class II transactivating factor, RFXAP, can cause MHC class II deficiency. These mutations abolish the expression of MHC class II genes and lead to the same clinical picture of immunodeficiency as in patients with mutations in the other two MHC class II regulatory genes.

Cell Line↗
PubMed1997

Th1-like cytokine production profile and individual specific alterations in TCRBV-gene usage of T cells from newly diagnosed type 1 diabetes patients after stimulation with beta-cell antigens.

In order to study cytokine production profile (IFN-gamma, IL-4 and TNF-alpha) and TCRBV-gene usage of peripheral autoreactive T cells from IDDM patients, we have generated antigen-specific T cell lines with either tetanus toxoid, insulinoma membranes or a single beta-cell protein, recombinant ICA69, which has been shown to be a target of both autoantibodies and T cells in IDDM. By semi-quantitative polymerase chain reaction (PCR) analysis, we have determined the composition of the T cell receptor repertoire of these T cell lines and compared this with the general peripheral repertoire. T cell responses against beta-cell antigens and tetanus toxoid (TT) were shown to be associated with IFN-gamma and TNF-alpha production, suggestive of a Th1-like phenotype of the T-cell lines. The production of IFN-gamma was significantly higher in T-cell lines generated with ISG compared to those generated with TT. The cytokine production profiles of the T-cell lines generated with ICA69 did not provide an obvious explanation for the inverse relation between cellular and humoral responses to this protein observed earlier. Upon stimulation with beta-cell antigens, outgrowth of T cells using a restricted set of TCRBV elements was observed in newly diagnosed IDDM patients. However, this skewing in TCRBV-gene expression was patient-specific rather than antigen-associated, since the T-cell repertoire that is used for the recognition of these antigens was, overall, heterogeneous.

Adolescent↗
PubMed1997

T cell receptor usage by HLA-DR3-specific T cell clones isolated from a renal allograft.

In order to evaluate the T cell receptor (TCR) usage by clones of human allograft infiltrating lymphocytes, this study utilized polymerase chain reaction (PCR) amplification of TCR transcripts from five clones which were previously shown to react with a human leucocyte antigen (HLA)-DR3 mismatch between a living related kidney donor and recipient. The five CD4+ (CD8-) clones, which were selected for TCR analysis, proliferated in response to HLA-DR3 and three of the clones were also cytotoxic against the same target cells. After identification of the TCRAV and TCRBV usage of the clones, the sequence of the TCR alpha and beta were determined by direct sequencing of the PCR product. The results indicate that several different TCRAV and TCRBV gene segments are used among the different clones, but the two clones that were both cytotoxic and proliferative in response to HLA-DR3 shared identical TCRAV27-J42-C and TCRBV13-D1-J1S2-C1 transcripts. The additional three clones showed various TCRAV and TCRBV transcripts, but evaluation of the CDR3 region of the TCR beta chain, corresponding to the peptide antigen binding sites, demonstrated shared amino acid motifs which resulted both from germline sequences and combinations of n-region and germline-derived codons. These results suggest that the repertoire for anti-HLA-DR3-reactive clones can include a diverse expression of TCR, but there may be selection for some clones, as well as conserved motifs in the CDR3 region of anti-DR3 specific clones.

Amino Acid Sequence↗
PubMed1996

The RAG cell line defines a new complementation group of MHC class II deficiency.

We previously described RAG, a mouse adenocarcinoma cell line, as deficient for the induction of major histocompatibility (MHC) class II antigens by IFN-gamma, but responding normally for MHC class I antigen stimulation and anti-viral protection. We had established that the fusion of RAG with various human cell lines restored the induction of MHC class II antigens, whenever the human chromosome 16 was present in somatic cell hybrids. Here we show that the RAG cell line does not exhibit any induction by IFN-gamma of DMA, DMB, and the invariant chain (Ii) mRNAs, and that the induction is restored in somatic cell hybrids containing human chromosome 16. In order to define the gene (designated F16) affected in the RAG cells, we performed a complementation analysis by fusing RAG with previously described human cell lines defective for MHC class II antigen expression (e.g., BLS cell lines), and which belong to five different complementation groups. Our data show that the resulting somatic cell hybrids present an inducible expression of mouse MHC class II antigens, Ii, DMA, and DMB. Therefore, the RAG cell line represents a yet undescribed cellular mutant affected in the expression of MHC class II antigens. In addition, we demonstrate that MHC class II antigens can be constitutively expressed in the RAG cell line when transfected with the cDNA encoding human CIITA driven by the RSV LTR promoter. Since the complementation analysis assessed that F16 and CIITA are distinct, our data suggest that F16 is required for the expression of CIITA.

Animals↗
PubMed1995

Clonal expansion of myelin basic protein-reactive T cells in patients with multiple sclerosis: restricted T cell receptor V gene rearrangements and CDR3 sequence.

Myelin basic protein (MBP)-reactive T cells are thought to play an important role in the pathogenesis of multiple sclerosis (MS). In some patients with MS, these autoreactive T cells display a limited heterogeneity in their epitope recognition and T cell receptor (TCR) variable (V) gene usage. These individual-dependent properties of MBP-reactive T cells have led to the speculation that they may represent clonal expansion in vivo in some MS patients. In the present study, 51 MBP-reactive T cell clones derived from patients with MS and healthy individuals were examined for their epitope recognition and the TCR V alpha and V beta gene rearrangements. The V gene junctional region sequences of identified alpha and beta genes were further analyzed to probe their clonal origins, as the sequences are unique for individual clones. Our data showed that 26 clones derived from nine patients with MS shared a predominant reactivity to the immunodominant regions of MBP, 84-102, 110-129 and 143-168, and used various TCR V alpha and V beta rearrangements. The V gene usage of the clones was restricted to certain V alpha V beta combination(s) in a given MS patient, but varied among different patients. The sequence analysis revealed that the clones generated from a given patient shared a limited or a single junctional region sequence pattern(s), indicating their oligoclonal or monoclonal origin(s). In contrast, 25 MBP-reactive T cell clones derived from normal individuals exhibited unfocused epitope recognition and V gene usage. Thus, the limited heterogeneity of MBP-reactive T cells in their structural and functional characteristics reflects their clonal expansion in vivo in some patients with MS.

Amino Acid Sequence↗
PubMed1995

Joint-derived T cells in rheumatoid arthritis proliferate to antigens present in autologous synovial fluid.

The histopathological features of rheumatoid joint-inflammation suggest that an antigen-driven activation of T cells plays a central role in the onset and/or perpetuation of the inflammatory process. However, the disease-associated antigens responsible for the activation of T cells in the joint are unknown. In this project we study the response of IL-2 expanded T-cell lines from the synovial fluid (SF) of rheumatoid arthritis (RA) patients against autologous SF in a proliferation assay. Sixteen out of 32 RA patients were found to have CD4+ T cells that proliferate in response to autologous SF. The presence of T cells able to respond to SF antigens in inflamed joints suggests that these T cells play an active role in the pathogenesis of RA. T cell clones reactive to autologous SF were isolated from SF-derived T-cell lines of two RA patients. All clones were of the CD4+, CD8-, alpha/beta+ phenotype. SF-reactivity of T-cell clones from the DR4/DR12-positive RA patient was restricted via the Dw4 subtype of DR4. SF reactivity of T cells of the DR12/DR15 patient was DP-restricted. Some of the T-cell clones responded specifically to autologous and not to allogeneic SF, whereas others revealed responsiveness against a limited number of allogeneic SF samples. The (restricted) specificity of T cells towards autologous SF antigens is indicative for heterogeneity of the epitopes recognized and argues against ubiquitous nonpolymorphic joint constituents as the relevant antigens recognized by the SF-autoreactive T cells.

Arthritis, Rheumatoid↗
PubMed1994

Functional and molecular characterization of B cell-responsive V delta 1+ gamma delta T cells.

Cells expressing the V delta 1+ gene segment are a minor gamma delta T cell population in human peripheral blood but predominate in epithelial and (inflamed) tissues. The characteristic dendritic-like morphology of these gamma delta T cells is consistent with their putative immune surveillance role in epithelia. Their function, however, remains unknown. We and others previously reported that a subset of V delta 1+ gamma delta T cells proliferates after stimulation with Epstein-Barr virus (EBV)-transformed B lymphoblastoid cell lines (LCL), but not with fresh peripheral blood-derived B cells. These responses were independent of the type of T cell receptor (TcR) gamma chain co-expressed with the V delta 1 chain. The in vivo relevance of this LCL-mediated activation as well as the nature of the stimulatory ligand on the LCL is not well established. In this study, we tested the proliferative response of V delta 1+ LCL-responsive T cells against non-EBV-transformed B cells, activated through CD40 by murine EL4 B5 cells, and to a panel of B cell lines differing in the expression of EBV nuclear antigen proteins and adhesion/co-stimulatory molecules. The role of the Epstein-Barr virus-derived antigen in the induction of this response could be excluded as the activated (non-EBV-transformed) peripheral blood B cells were also able to induce a proliferative response in the LCL-responsive V delta 1+ T cells. Therefore, the stimulatory ligand on B cells is of cellular rather than of viral origin, and its expression is up-regulated upon activation of B cells. The expression of B7 and CD39 molecules on the surface of activated B cells appeared to be crucial since antibodies to these structures could block the induction of proliferation of the V delta 1+ T cells. Finally, we investigated the diversity of the responding V delta 1+ gamma delta T cell clones by sequence analysis of the TcR delta junctional regions. No restricted V-D-J sequences were found among the LCL-responsive V delta 1+ T cell clones, arguing strongly against a mono- or oligoclonal V delta 1+ gamma delta T cell response to LCL. These findings may explain the presence of polyclonally activated V delta 1+ T cells in inflamed tissues where activated B cells are often present.

Adenosine Triphosphatases↗
PubMed1993

Lymphokine gene transcription in CD4+CD8- T cells of a type III bare lymphocyte syndrome patient.

In this study we analyzed the impact of a MHC class-II-deficient environment on the differentiation of CD4+CD8- T lymphocytes into functional defined subsets of lymphokine-producing T-helper cells. To this end a CD4+CD8- T-cell line and CD4+CD8- T-cell clones, isolated from PBMCs of a type III BLS patient, were stimulated in vitro with anti-CD3 and PMA and assessed for lymphokine transcription patterns. The results of these analyses show that CD4+CD8- T cells that have matured in a MHC class-II-deficient environment display lymphokine transcription patterns that resemble those of MHC class-II-expressing family control-derived CD4+CD8- T cells.

CD4 Antigens↗
PubMed1993

T-cell receptor V-gene usage in synovial fluid lymphocytes of patients with chronic arthritis.

In this study we analyzed the usage frequencies of the TCR V-gene segments by alpha beta+ T cells present in synovial fluid of 17 patients with chronic arthritis, including rheumatoid arthritis. The results of this study, obtained from semiquantitative PCR analyses, showed that in all patients most of the TCR V alpha- and V beta-gene segments could be detected both in fresh PBMCs and in fresh SFMCs. The relative frequencies of use of these V-region genes were variable between the different patients. Although there was some skewing of increased usage frequencies of particular TCR V alpha and V beta genes among SFMC-derived TCRs when compared with PBMCs, we could not correlate such increased TCR V-gene usage with the inflammation in the joints as a disease-specific marker.

Adult↗
PubMed1993

Analysis of T cell lines from rejecting renal allografts.

Acute rejection after renal allotransplantation is characterized by the presence of a mononuclear cell infiltrate in the interstitium with involvement of tubuli. In a previous study on renal histology we showed that tubular damage by graft infiltrating cells (GIC) is a sign of clinically significant rejection. We cultured proximal tubular epithelial cells (PTEC) and T cells bearing the interleukin 2 (IL-2) receptor from biopsies after transplantation. In vitro outgrowth of T cells from the biopsy was significantly (P = 0.0014) related to histological signs of graft rejection. Of the T cell lines generated from 25 biopsies, only five lines showed no or low cytotoxicity against donor PTEC. Three cell lines were cytotoxic towards donor PTEC, but not against PHA stimulated donor splenocytes, suggesting tissue specificity of GIC. Treatment of PTEC with interferon (IFN) gamma for 72 hours to upregulate MHC class I and to induce MHC class II expression did not necessarily result in an increased susceptibility to lysis. However, three PTEC lines displayed an increment of susceptibility to lysis after IFN gamma treatment. Analysis of one T cell line from the same graft revealed a high percentage of CD4 positive cells, compatible with a class II restricted cytotoxicity. This was confirmed by blocking experiments using anti-CD4, anti-CD8, anti-class I, and anti-class II antibodies. Blocking experiments were done with 12 of these 25 lines. Anti-CD3 and anti-CD18 antibodies inhibited cytotoxicity in every case, showing that cytotoxicity was T cell mediated.(ABSTRACT TRUNCATED AT 250 WORDS)

CD4 Antigens↗
PubMed1992

T-cell receptor beta-chain gene usage in the T-cell recognition of Mycobacterium leprae antigens in one tuberculoid leprosy patient.

The beta chain of the T-cell antigen receptor present on 20 T-cell clones isolated from a tuberculoid leprosy patient was studied by gene rearrangement and PCR analysis. These T-cell clones all responded to Mycobacterium leprae-encoded protein antigens, and 8 of them specifically recognized peptides of the mycobacterial 65-kDa heat shock polypeptide (65hsp). All T-cell clones studied were HLA-DR-restricted (DR2 or -3). In the DR3-restricted group, 7 of 10 used a beta-chain variable region V beta 5 gene family member, whereas in the DR2-restricted group, 2 of 10 T-cell clones used a V beta 5 gene segment and 5 used the V beta 18 gene segment. The deduced amino acid sequences of the beta chain from 8 T-cell clones have revealed that 3 of 4 DR3-restricted T-cell clones expressed the V beta 5.1 gene segment whereas the fourth DR3-restricted T-cell clone employed a V beta 5 family member not previously described. The V beta 5.1-positive T-cell clones all recognized the same 65hsp peptide from residues 2 to 12. The N-D-N segment (where D is diversity) of the junctional region of these T-cell clones was very similar, despite different beta-chain joining gene segments. Of the 4 DR2-restricted T-cell clones investigated, 3 used the V beta 18 gene segment and recognized the 65hsp peptide from residues 418 to 427. In conclusion, within this panel of M. leprae-reactive T-cell clones, the DR3-restricted T-cell clones mainly used a V beta 5 gene segment, whereas the DR2-restricted clones employed preferentially the V beta 18 gene segment.

Amino Acid Sequence↗
PubMed1990

Analysis of early fetal T-cell receptor delta chain in humans.

In the mouse it has been found that a number of T-cell receptor (Tcr) gd phenotypes are generated during fetal thymic development. To examine whether such "waves" of Tcrgd phenotypes can be found in man, we studied the V-region usage and junctional diversity of the T-cell receptor delta chain in human fetal and post-partum thymocytes and peripheral blood T cells. Using the polymerase chain reaction (PCR)-amplification technique it was found that in fetal thymocytes of 15-17 weeks of gestation the Tcrd-V3 gene segment was mainly employed, whereas in post-partum thymocytes the Tcrd-V1 gene segment was preferentially used. These Tcrd-V3 transcripts contained only a single D element (D delta 3) and a limited random nucleotide insertion. The D delta 3 element was also present in Tcrd-V3-containing transcripts derived from peripheral blood gamma delta Tcr+ clones. These data suggest that a wave of Tcr gamma delta might exist early in human fetal development that preferentially use the Tcrd-V3 gene segment.

Base Sequence↗
PubMed1989

A novel T-cell-defined HLA-DR polymorphism not predicted from the linear amino acid sequence.

Recent investigations have shown that alloreactive T cells are capable of responding to structures defined by specific linear amino acid sequences on class II molecules. In the present study we show that also a polymorphism can be recognized that is not defined by such linear amino acid sequences. Two human T-cell clones, sensitized to DRw13 haplotypes, are described. The description of clone c50 serves to exemplify the first model. This DRB1-specific clone responds to stimulator cells that carry DR molecules, different in their DRB1 first and second hypervariable regions (HV1 and HV2) but identical in their HV3 regions (i.e., DRw13,Dw18; DRw13,Dw19; DR4,Dw10; and DRw11,LDVII). The second clone, c1443, behaves nonconventionally. It responds to DRw13,Dw18; DRw13,Dw19; and DR4,Dw4 stimulator cells, although no specific amino acid sequence is shared between these specificities. The latter pattern of reactivity suggests the existence of a novel polymorphism recognized by alloreactive T cells. This particular polymorphism may also be biologically significant.

Amino Acid Sequence↗
PubMed1989

Rearrangement and expression of T-cell receptor delta genes in T-cell acute lymphoblastic leukemias.

We have analyzed T-cell receptor delta (TcR-delta) gene rearrangement and transcription in appropriately phenotyped mononuclear cells derived from 12 patients with T-cell acute lymphoblastic leukemia (T-ALL). The T-ALL cells were also analyzed for rearrangement and transcription of the T-cell receptor(TcR)-beta and gamma genes as well as for the presence of TcR-alpha gene transcripts. Four T-ALLs expressed TcR-gamma delta at the cell surface, while three expressed TcR-alpha beta. The other five T-ALLs did not express a TcR-CD3 complex on their cell membrane. The TcR-gamma delta + T-ALL had rearranged both TcR-delta gene alleles and contained mature 2.2 and 1.5 kb TcR-delta transcripts. In one case, immature 1.9 and 1.2 kb TcR-delta transcripts were also found. Furthermore they contained mature TcR-gamma mRNA, mature or immature TcR-beta mRNA, but no TcR-alpha mRNA. The three TcR-alpha beta + T-ALLs contained mature alpha and beta transcripts, but lacked TcR-delta transcripts as a result of deletion of both TcR-delta gene alleles. These data are in line with a mutually exclusive expression of TcR-alpha and -delta genes, which may be important to ensure the presence of only one type of TcR per T cell. One of the five CD3- T-ALLs had germline TcR-beta, gamma, and delta genes. The other four CD3- T-ALLs had rearranged their TcR-beta, gamma, and delta genes and contained immature 1.9 and 1.2 kb TcR-delta gene transcripts. Remarkably, one of these T-ALLs also contained TcR-alpha transcripts in addition to the immature TcR-delta transcripts, which was in line with the deletion of one TcR-delta gene allele and rearrangement of the other allele. This suggests that prevention of dual receptor expression may not only be regulated by the presence of germline TcR-alpha genes in TcR-gamma delta + cells or by deletion of both TcR-delta gene alleles in TcR-alpha beta + cells, but also via other regulation mechanisms. Finally, our data indicated that the combinatorial repertoire of the TcR-delta genes is limited, which has also been described for the TcR-gamma genes.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

A T cell-specific enhancer is located in a DNase I-hypersensitive area at the 3' end of the CD3-delta gene.

During intrathymic differentiation, the genes coding for the T cell receptor/CD3 (TCR/CD3) complex are expressed in stages resulting in surface expression of competent receptors on the most mature T cells. The CD3-delta, gamma and epsilon proteins, which are expressed intracellularly in the earliest detectable cells of T lineage, form the core of the TCR/CD3 complex. In the present investigation aimed at understanding the tissue specific expression of the murine CD3-delta gene, a T cell specific DNase I hypersensitive site was found 0.6 kb downstream of the polyadenylation site of the gene. A 0.4 kb genomic fragment encompassing this hypersensitive site exhibited properties of a strictly T cell-specific transcriptional enhancer which acts in a position- and orientation-independent manner. However, the activity of the promoter region was not found to be T cell restricted. Within this novel T cell-specific enhancer region, sequence motifs were found which are shared with the promoters of both the mouse and human CD3-delta genes; in this region we also found sequence homologies to the enhancer core element of the thymotropic viruses SL3 and RadLV. These findings suggest that regulatory elements 3' of the CD3-delta gene are at least in part responsible for its exclusive expression in thymus-derived lymphocytes.

Animals↗