The V delta gene usage by freshly isolated T lymphocytes from synovial fluids in rheumatoid synovitis: a preliminary report

Integral Roles for Integrins in γδ T Cell Function

Integrins are adhesion receptors on the cell surface that enable cells to respond to their environment. Most integrins are heterodimers, comprising α and β type I transmembrane glycoprotein chains with large extracellular domains and short cytoplasmic tails. Integrins deliver signals through multiprotein complexes at the cell surface, which interact with cytoskeletal and signaling proteins to influence gene expression, cell proliferation, morphology, and migration. Integrin expression on γδ T cells (γδTc) has not been systematically investigated; however, reports in the literature dating back to the early 1990s reveal an understated role for integrins in γδTc function. Over the years, integrins have been investigated on resting and/or activated peripheral blood-derived polyclonal γδTc, γδTc clones, as well as γδ T intraepithelial lymphocytes. Differences in integrin expression have been found between αβ T cells (αβTc) and γδTc, as well as between Vδ1 and Vδ2 γδTc. While most studies have focused on human γδTc, research has also been carried out in mouse and bovine models. Roles attributed to γδTc integrins include adhesion, signaling, activation, migration, tissue localization, tissue retention, cell spreading, cytokine secretion, tumor infiltration, and involvement in tumor cell killing. This review attempts to encompass all reports of integrins expressed on γδTc published prior to December 2017, highlights areas warranting further investigation, and discusses the relevance of integrin expression for γδTc function.

gammadelta T cells contribute to the systemic immunoglobulin E response and local B-cell reactivity in allergic eosinophilic airway inflammation

Allergic airway inflammation induced in mice is T-cell dependent and recruitment of eosinophils to airspaces requires both alphabeta and gammadelta T cells. From previous studies it is evident that alphabeta T cells are essential for the allergic T helper type 2 (Th2)-like response, while the mechanistic contribution of gammadelta T cells is still unclear. In this study, we have investigated the role of gammadelta T cells in allergic airway eosinophilia induced by ovalbumin hypersensitivity. By comparing the responsiveness to sensitizing allergen of wild-type mice with that of T-cell receptor gammadelta knockout mice (TCRgammadelta KO) we demonstrated that mice lacking gammadelta T cells are defective in the systemic ovalbumin-specific immunoglobulin E (IgE) response. Furthermore, after aerosol challenge with allergen, gammadelta T-cell deficient mice exhibited a significantly decreased migration of B cells and natural killer cells to airways and reduced levels of allergen-specific IgG and IgA in bronchoalveolar lavage fluid. The role for B cells in the airway inflammation was indicated by the impaired ability of mice lacking functional B cells to evoke an eosinophilic response. The diminished eosinophilia in TCRgammadelta KO mice could not be explained by a defective Th2 activation since these mice displayed a normal IgG response in serum and an unaffected IG2b/IgG1 ratio in airways. Analysis of immunoregulatory cytokines in isolated lung tissue, thoracic lymph nodes and spleen further supported the notion that these mice are able to evoke a sufficient activation of T helper cells and that gammadelta T cells are not required for maintaining the Th2 profile. These results indicate that gammadelta T cells contribute to allergic airway inflammation by pathways separate from classical Th2 immune activation.

Role of heat shock proteins in protection from and pathogenesis of infectious diseases

Increased synthesis of heat shock proteins (hsp) occurs in prokaryotic and eukaryotic cells when they are exposed to stress. By increasing their hsp content, cells protect themselves from lethal assaults, primarily because hsp interfere with the uncontrolled protein unfolding that occurs under stress. However, hsp are not produced only by stressed cells; some hsp are synthesized constitutively and perform important housekeeping functions. Accordingly, hsp are involved in the assembly of molecules which play important roles in the immune system. It is not surprising that due to their wide distribution and their homology among different species, hsp represent target antigens of the immune response. Frequent confrontation of the immune system with conserved regions of hsp which are shared by various microbial pathogens can potentiate antimicrobial immunity. However, long-term confrontation of the immune system with hsp antigens which are similar in the host and invaders may convert the immune response against these host antigens and promote autoimmune disease. This review provides an overview of the role of hsp in immunity with a focus on infectious and autoimmune diseases.

A minimised hammerhead ribozyme with activity against interleukin-2 in human cells

A "minizyme" is a smaller version of the hammerhead ribozyme, in which stem-loop II has been replaced by a short linker. Here, we have synthesised a DNA-containing minizyme and a ribozyme, which are designed to cut within a 15-nucleotide sequence in human interleukin-2 mRNA, and have tested for their activity in vitro and in cells. In vitro at 37 degrees C, a minizyme with linker of sequence d(GTTTT) cleaves a 15-ribonucleotide synthetic substrate 5-fold slower than does the full-sized ribozyme. In human cells, the minizyme inhibits the production of interleukin-2 protein to a similar extent as does the ribozyme. Also, the minizyme and the ribozyme are more effective in cells than any of three controls: an inactive minizyme, a 15-nucleotide antisense DNA, or DNA of random sequence. The positive effect observed in cells indicates that minizymes may be useful as pharmaceuticals.

Increased serum and synovial fluid antibodies to immunoselected peptides in patients with rheumatoid arthritis

OBJECTIVES

To investigate the role of potential immunoselected phages displaying random peptides in addition to possible antigen leads in rheumatoid arthritis (RA) by assaying the levels of synovial fluid (SF) and serum antibodies to synthetic peptides.

METHODS

Serum and SF antibodies from patients and controls were measured using an enzyme linked immunosorbent assay (ELISA).

RESULTS

Sera and SF from RA patients reacted significantly more strongly to a 12 amino acid peptide, EFHELGDIAIAA, that shares a significant homology with collagen type IX, than did SF and sera from control groups (p < 0.0209 and p < 0.0115, respectively). In addition, the humoral responses to a 15 amino acid peptide, GGYGDGGAHGGGYGG, derived from the glycine-rich cell wall protein (GRP) 1.8, and to a 16 amino acid synthetic peptide, LGSISESRRALQDSQR, derived from the Proteus haemolysin protein were significantly stronger in RA patients compared with healthy individuals (p < 0.0001 and p < 0.0011, respectively).

CONCLUSION

Our data indicate that peptide phage libraries can be used as tools for the identification of the (auto)antigen leads that may be responsible for the initiation, perpetuation, or both, of the immune response in patients with RA.

Limited heterogeneity of rearranged T cell receptor V alpha and V beta transcripts in synovial fluid T cells in early stages of rheumatoid arthritis

OBJECTIVE

The identification of activated T cells in synovial fluid and synovium, and the association of rheumatoid arthritis (RA) with specific HLA-DR restriction elements, strongly suggest that these T cells play a critical role in the etiology and pathogenesis of RA. Analysis of the T cell receptor (TCR) repertoire in the early stages of RA might be an approach to identify those T cells involved in the initiation and/or perpetuation of the disease.

METHODS

TCR V alpha and V beta transcripts of synovial T cells, sampled at the early stages of RA, were amplified by reverse transcriptase-polymerase chain reaction. HLA-DR subtyping was determined by serologic analysis and dot-blot hybridization of polymerase chain reaction amplification products using digoxigenin-labeled, sequence-specific oligonucleotide probes.

RESULTS

Our findings showed a limited heterogeneity of V alpha and V beta TCRs in synovial fluid T cells, and a preferential usage of TCR V alpha 17 in early RA. In contrast, in the later stages of RA, a more polyclonal TCR V alpha and V beta gene usage was observed.

CONCLUSION

Our results support the view that induction of RA is driven by an oligoclonal immune response to an unknown antigen. These findings also suggest a pathogenetic role for V alpha 17 T cells in the early stages of RA.

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.

Analysis of gamma delta V region usage in normal and diseased human intestinal biopsies and peripheral blood by polymerase chain reaction (PCR) and flow cytometry

The intestinal population of gamma delta T cell receptor (TCR)-bearing cells was characterized with regard to V delta and V gamma subtype expression. For this purpose, we utilized V gene-specific PCR of mRNA prepared from intestinal biopsies. Predominant expression of the V delta 1 subtype was demonstrated in the small intestine of patients with coeliac disease and in the inflamed colon of patients with inflammatory bowel diseases (IBD: ulcerative colitis and Crohn's disease) as well as in colon biopsies taken from macroscopically normal areas of colon. Although intestinal gamma delta T cells preferentially expressed V delta 1, other V delta transcripts could be detected, of which V delta 2 and V delta 5 were commonly expressed. Analysis of biopsies from mesenteric lymph nodes demonstrated a V delta repertoire similar to the mucosa. In peripheral blood on the other hand, high expression of both V delta 2 and V delta 1 was found. The predominant expression of V delta 1 transcripts in the intestinal mucosa of IBD patients correlated well with protein cell surface expression as analysed by flow cytometry using V delta 1- and V delta 2-specific antibodies. Selective expansion of gamma delta T cells could not be demonstrated within the inflamed mucosa as shown by mRNA analysis and flow cytometry. Instead, IBD patients demonstrated a decreased proportion of TCR gamma delta-carrying T cells in the inflamed mucosa compared with macroscopically normal area of colon. On the other hand, a significantly increased percentage of T cells bearing the gamma delta TCR was found in peripheral blood of patients with Crohn's disease compared with healthy individuals, indicating that local mucosal inflammation may influence the circulating gamma delta T cell population.

V delta 1+ gamma/delta T lymphocytes infiltrating human lung cancer express the CD8 alpha/alpha homodimer

Murine gamma/delta T lymphocytes localize to different epithelial tissues and are phenotypically distinct from peripheral gamma/delta T cell-populations in that they show limited TCR diversity, express the CD8 alpha/alpha homodimer and lack the CD8 beta chain. In humans, a compartmentalization of gamma/delta cells sharing similar phenotypic features has been documented to date only in the case of intestinal epithelium. In the present study we show that about half of V delta 1+ (as well as V delta 1-V delta 2-) gamma/delta lymphocytes, which can be selectively expanded from human lung cancers, coexpress the CD8 alpha/alpha homodimer. The accumulation of intraepithelial CD8+ gamma/delta+ lymphocytes might then be a more general phenomenon, possibly as a result of common mechanisms operating at those sites.

The cytotoxic analysis of T cell receptor V delta 1+ T cell lines derived from the synovial fluid of rheumatoid arthritis patients

We established six human T cell lines derived from rheumatoid arthritis synovial fluid (RASF). Phenotypically, T cell receptor (TCR) gamma delta T cells occupied the majority of these lines and most of them expressed the TCR V delta 1 molecule. In contrast, V delta 2+ T cells, the majority population of peripheral blood gamma delta T cells, were rarely detected in these lines. To study the immunobiological roles of RASF V delta 1+ T cells in RA development, their cytotoxic profile was studied. The results showed that these T cells selectively lysed Daudi, but not K562 cells. The cytotoxic response was MHC-unrestricted, and was inhibited by anti-CD3 MoAb. Moreover, the cold target inhibition assay showed that the cytotoxicity was competitively inhibited by autologous and allogeneic primarily cultured RA synovial cells as well as synovial sarcoma and chondrosarcoma lines. However, PBL did not inhibit this cytotoxicity. These data suggest that V delta 1+ T cells in RASF may recognize the antigen which is commonly expressed on the surface of Daudi and the cells derived from RA synovium. We can assume that the cytotoxic V delta 1+ T cells are selectively expanded in RASF, playing a significant role for the pathogenesis of certain RA cases.

The biased V gamma gene usage in the synovial fluid of patients with rheumatoid arthritis

Taking advantage of the reverse transcriptase-polymerase chain reaction (RT-PCR), we have analyzed T cell receptor gamma-chain mRNA of synovial fluid gamma/delta T cells from patients with rheumatoid arthritis (RA) in comparison with those of peripheral blood mononuclear cells (PBMC) from RA patients and healthy individuals. The quantitative RT-PCR method in conjunction with nucleotide sequencing revealed the frequent usage of the V gamma 3 gene segment in RA synovial fluid mononuclear cells (SFMC) (p < 0.01) which in PBMC of healthy individuals occurred rarely. PBMC of most healthy individuals expressed the V gamma 9 gene predominantly (p < 0.01) as expected. However, only half of RA patients showed elevated levels of the V gamma 9 gene expression in their PBMC. The gamma-chain mRNA containing the V gamma 3 gene in RA SFMC showed no conserved junctional sequence (complementarity-determining region 3). To investigate the nature of ligands recognized by the V gamma 3-bearing T cells, we analyzed V gamma gene usage of RA SFMC, RA PBMC, and normal PBMC stimulated with Mycobacterium tuberculosis (MT) or MT plus interleukin-2 since there is mounting evidence of high reactivity of RA SFMC to MT and mycobacterial heat-shock protein 65. However, the V gamma usage appeared to be mostly V gamma 9 in RA SFMC, RA PBMC and normal PBMC. Taken together these results suggest that an as yet unknown antigen(s) (other than MT) might select gamma/delta T cells expressing the V gamma 3 gene in RA SFMC.

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.

A subset of V delta 1+ T cells proliferates in response to Epstein-Barr virus-transformed B cell lines in vitro

It has previously been shown that murine tissue derived T-cells expressing the gamma delta T-cell receptor can respond to autologous (stressed) cells implying the recognition of an autoantigen. Here we report that a large proportion of human synovial tissue and peripheral blood derived V delta 1+ gamma delta T-cell clones proliferate in response to stimulation with autologous and allogeneic EBV-transformed B-lymphoblastoid cell lines (LCL). In contrast, V delta 1- gamma/delta and alpha/beta TCR+ T-cell clones isolated from the same tissue samples did not display proliferation towards the LCL. The proliferative response of these V delta 1+ clones was dependent on contact between responder and stimulator cells and could be blocked by a MoAb to LFA-1 and by antibodies to the gamma delta TCR/CD3 complex. Because the responses of these clones to LCL cells appear to be independent of the gamma-chain co-expressed with the V delta 1-chain these resemble a superantigen response. The capacity of this subset of V delta 1+ T-cell clones to proliferate after stimulation with LCL may imply the recognition of an endogenous epitope. Moreover, since so far we have been able to isolate only LCL reactive gamma delta T-cell clones from synovial tissue and peripheral blood of reactive arthritis patients and not from peripheral blood of healthy individuals, the frequency of such 'autoreactive' gamma delta cells may be higher in these patients.

A high proportion of the V delta 1+ synovial fluid gamma delta T cells in juvenile rheumatoid arthritis patients express the very early activation marker CD69, but carry the high molecular weight isoform of the leucocyte common antigen (CD45RA)

We have previously shown that gamma delta T cells in the synovial compartment of patients with juvenile rheumatoid arthritis (JRA) express activation antigens (CD69 and HLA-DR) and that they are predominantly of the V delta 1 subset. In this study we have analysed the expression of activation antigens (CD69 and HLA-DR) and different isoforms of the leucocyte common antigen (CD45RO and CD45RA) on the V delta 1 and the V delta 2 subsets of gamma delta T cells in paired samples of synovial fluid and peripheral blood of nine patients with JRA, and in the peripheral blood of five children with idiopathic scoliosis. In the synovial fluid of children with JRA, there were significantly more V delta 1+CD69+ and V delta 2+CD69+ cells compared with the peripheral blood of the same patients. In contrast, however, in the synovial fluid the V delta 1 and the V delta 2 subsets differed with respect to the expression of the two isoforms of the leucocyte common antigen. The majority of the V delta 1+ cells expressed the high molecular weight isoform (CD45RA+) while most of the V delta 2+ cells carried the low molecular weight variant (CD45RO+) of this molecule.

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.

TCR gamma/delta+ cell subsets in the synovial membranes of patients with rheumatoid arthritis and juvenile rheumatoid arthritis

Using a peroxidase/anti-peroxidase immunohistochemical staining method, we examined sections of inflammatory synovial membranes from 13 patients with juvenile rheumatoid arthritis (JRA) and 11 with rheumatoid arthritis (RA). The relative numbers of TCR gamma/delta+ cells and the proportions of V delta 1+ and V delta 2+ subsets were recorded in the areas of the membranes most heavily infiltrated by CD3+ cells. In the JRA group, the majority (8/13) of the membranes had TCR gamma/delta+ cells which contributed between 5 and less than 10% of the total number of CD3+ cells. In the RA synovial membranes examined, 5/11 samples had between 5 and 10% TCR gamma/delta+ cells, but in another 5 TCR gamma/delta+ cells contributed to between 10 and 20% of CD3+ cells. No significant difference was noted between the two patient groups. However, the range of values found in the RA membranes appeared to be slightly higher in comparison to previously reported values for RA synovial fluid, peripheral blood and eluted synovial membrane T cells. Analysis of the relative proportions of the V delta 1+ and V delta 2+ subsets revealed a significant dominance of V delta 1+ cells in RA membranes and approximately equal numbers of the two populations in the JRA patients. As the majority of peripheral blood TCR gamma/delta+ cells use the V delta 2 segment this suggests a preferential homing or expansion of the V delta 1+ cells in both RA and JRA synovium. The overall distribution pattern of the TCR gamma/delta+ and V delta 1+ and V delta 2+ cells was also recorded. These cells mostly accumulated in the lymphoid-like tissues and in the perivascular area in the tissues of both RA and JRA patients. Occasionally, augmented numbers of these cells were found in the subsynovial layer or in the loose connective tissue. In the majority of cases, only a few TCR gamma/delta+ cells were located in the synovial layer. The function and the possible pathogenetic importance of these TCR gamma/delta+ cells have not so far been determined.

Limited heterogeneity of T cell receptor variable region gene usage in juvenile rheumatoid arthritis synovial T cells

The aim of this study was to determine whether synovial fluid (SF) T cells in patients with juvenile rheumatoid arthritis (JRA) are restricted in their T cell receptor (TcR) gene repertoire. The quantitative polymerase chain reaction (QPCR) was used to compare the transcription of V beta and V alpha gene families in freshly isolated SF T cells, in interleukin-2 receptor-positive (IL-2R+) T cells and in peripheral blood (PB) T cells from 18 patients. Significantly less V beta families are detected in SF when compared with PB (p greater than 0.0003). The TcR V beta gene usage by IL-2R+ T cells was even less heterogeneous when compared with freshly isolated SF T cells (p greater than 0.0002). Freshly isolated SF T cells from the left and the right knees of four patients transcribed the same V beta families. Furthermore, we demonstrate that in SF the distribution of certain TcR V beta gene segments in CD4+ and CD8+ T cells differed from that in PB of the same patient. The TcR V alpha usage was studied in IL-2R+ T cells from six patients who had shown restriction in their SF TcR V beta gene usage. Only two to five TcR alpha transcripts were detected in three of these patients while a broad TcR V alpha usage was seen in the other three patients. Sequence analysis of the SF V beta 20 cDNA clones generated from the IL-2R+ T cells of two patients demonstrated an oligoclonal expansion. Taken together, our data could indicate an antigen- and/or superantigen-driven expansion of selected T cells in the synovial compartment.

T cell receptor diversity and activation markers in the V delta 1 subset of rheumatoid synovial fluid and peripheral blood T lymphocytes

In the present study we have characterized the gamma/delta T cell receptor (TcR) population in synovial fluid (SF) and peripheral blood (PB) of patients with chronic inflammatory arthritis. By double staining we have shown that (a) synovial V delta 1+ cells have a high expression of activation markers CD45R0 ("memory cells") and HLA-DR as compared to PB, indicating a preactivated population of V delta 1-carrying T cells in vivo and (b) interleukin 2-induced expansion of synovial cells yields a high proportion of gamma/delta in most samples expressing predominantly the V delta 1 TcR. Junctional sequence analysis of the TcR delta chain from interleukin 2-expanded PB cell lines demonstrated a polyclonal V delta 1 population in three out of three samples. In SF cell lines three out of four samples were polyclonally expanded. In SF from one patient, however, a limited repertoire of expressed V delta 1 genes was found. Altogether, our data demonstrate the presence of preactivated V delta 1-expressing cells in the synovial compartment. This V delta 1 population is predominantly polyclonal, except in one patient where oligoclonally expanded V delta 1 cells were detected.

Pathogenic autoantibody-inducing gamma/delta T helper cells from patients with lupus nephritis express unusual T cell receptors

In previous work, we found that only 59 (15%) of 396 "autoreactive" T cell clones derived from five patients with lupus nephritis had the ability to selectively augment the production of pathogenic anti-DNA autoantibodies and the majority (49/59) of those autoimmune T helper (Th) clones were CD4+. Surprisingly, 7 of those Th clones were CD4-/CD8- and gamma/delta TCR+, capable of augmenting the production of pathogenic anti-DNA autoantibodies up to 125-fold. The gamma/delta Th clones responded in a MHC-nonrestricted manner to some endogenous autoantigen associated with heat shock proteins (HSP60) on the lupus B cells. The gamma/delta TCR genes expressed by 4 of these Th clones were amplified and sequenced here. Three of the 4 Th clones, each from a different lupus patient, expressed a gene from the V gamma 1 subgroup. Moreover, 2 of the Th clones expressed V delta 5, and the others V delta 1 or V delta 3. These TCRs are rarely expressed by peripheral blood gamma/delta T cells of normal adult humans. The predominant gamma/delta T cells in human peripheral blood express V gamma 2 (V gamma 9) and V delta 2 TCR genes, including HSP-responsive T cells. None of the lupus Th clones expressed this combination of TCR genes. In addition, some of these pathogenic autoantibody-inducing Th clones from the lupus patients had limited diversity and few N-nucleotide additions in their gamma/delta TCR junctional regions (CDR3), thus resembling fetal gamma/delta thymocytes early in ontogeny.

Preformed ribozyme destroys tumour necrosis factor mRNA in human cells

Maintaining RNA stability is a major problem in the delivery of preformed inhibitory RNA to target cells. In this study, we delivered a hammerhead ribozyme directed against tumour necrosis factor alpha into human promyelocytic leukaemia cells by cationic liposome-mediated transfection. Delivering a ribozyme in this manner reduced by 90% and 85% tumour necrosis factor alpha mRNA and protein, respectively. A modified ribozyme with a bacteriophage T7 transcription terminator at its 3' end was more stable than one lacking this sequence. This indicates that ribozyme stability can be improved by the addition of terminal sequences expected to protect against cellular nucleases.

Immunohistologic study of T-cell receptor delta-chain expression in rheumatoid synovial membranes

Lymphocytes expressing gamma delta T-cell receptors (TCRs) have been shown to be reactive to mycobacterial antigens as well as the so-called stress proteins. The detection of increased numbers of gamma delta cells in the synovial fluid and peripheral blood of some patients with rheumatoid arthritis has suggested a potential role for these lymphocytes in the pathogenesis of this disorder. Twenty-three rheumatoid synovial membranes were studied using immunohistology and monoclonal antibodies in an attempt to define the patterns of distribution of gamma delta T cells in rheumatoid synovitis. Consecutive sections were stained for T1(CD5), T4(CD4), T8(CD8), TAC(CD25), the delta-chain markers delta TCR1 and delta TCS1, and the beta-chain marker beta F1. Our results show some regional differences in the distribution of CD4 and CD8 cells, the former being prominent in the lymphocytic aggregates and the latter most prominent in diffuse infiltrates immediately adjacent to the synovial lining layer. All tissues showed extensive staining for beta F1; an estimated average of more than 90% of T cells expressed alpha beta TCR. The majority of samples showed limited staining for both delta-chain antibodies, with 20 of the 23 tissues appearing to have less than 1% of T lymphocytes expressing these markers. Three tissues stained extensively for both delta TCR1 and delta TCS1 in particular areas of the section. In these areas, small perivascular lymphocytic aggregates appeared to be composed mainly of gamma delta cells. TAC staining was virtually absent in all areas and tissues. It was concluded that the majority of T lymphocytes infiltrating rheumatoid synovial membranes express alpha beta TCR.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Immune responses to 18.6 and 30-kDa mycobacterial antigens in rheumatoid patients, and V beta usage by specific synovial T-cell lines and fresh T cells

We have investigated both the humoral and the cellular immune responses of patients with juvenile rheumatoid arthritis (JRA) and rheumatoid arthritis (RA) to mycobacterial antigens. The JRA group was not Bacillus Calmette Guerin (BCG) vaccinated whilst the majority of the RA group was. As determined by immunoblotting, 79% of sera from patients with JRA reacted mainly with a 18.6-kDa protein (P18.6), whilst 70% of sera from patients with RA reacted mainly with a 30-kDa protein (P30) of BCG, M. tuberculosis and M. kansasii. In contrast, only a moderate proportion of the control sera (25% of adult and 20% of children) showed reactivity to P30, and none of the samples had significant reactivity with the P18.6 antigen. Furthermore, T-cell proliferation to the P18.6 and P30 antigens was detected in the majority of JRA and RA patients, and was nearly always higher in synovial fluid (SF) than in the peripheral blood (PB). We also investigated the usage of V beta family genes in P18.6 and P30 antigen-specific T-cell lines established from the SF of one patient with active RA. We showed that V beta 2, -4, -5, -6, -7, -14, -17, -18 and V beta 19 were over-represented compared with other known V beta families. We also noted that the proportion of V beta 14 was higher in freshly isolated SF mononuclear cells compared with the blood in this patient and in 2 out of 4 other RA patients examined. Other V beta families such as V beta 6, V beta 8, V beta 16, V beta 18 and V beta 19 were also over-represented in the SF compared with the blood in some patients. Taken together our results provide more information concerning the role of mycobacterial antigens in RA and suggest that there may be an in vivo clonal expansion of T lymphocytes in the synovium.

Reduction in T gamma delta cell numbers and alteration in subset distribution in systemic lupus erythematosus

We have studied the distribution of T gamma delta cells in the peripheral blood of 35 patients with systemic lupus erythematosus (SLE) and 36 age-matched controls. The monoclonal antibodies A13, BB3 and Ti gamma A, which are specific for the V delta 1, V delta 2 and V delta 9 gene products respectively, were used to define T gamma delta cell subsets. A significantly lower frequency of T gamma delta cells was found in peripheral blood lymphocytes of SLE patients compared with normal subjects (3.2% versus 5.9%). There was a marked reduction in the V delta 2+ subset of T gamma delta cells, which resulted in a reversal of the ratio of V delta 2+/V delta 1+ cells from 4.34 to 0.56. No correlation was found with either clinical or laboratory measures of disease activity. These results suggest that the observed changed in T gamma delta subset distribution are related to the SLE itself, and not secondary to changes in disease activity.

Gamma/delta T cell receptor positive T cells in the inflammatory joint: lack of association with response to soluble antigens

In patients with inflammatory synovitis, the proliferative response by lymphocytes from synovial fluid to soluble mycobacterial antigens is enhanced relative to those from peripheral blood. Earlier studies suggested that gamma/delta T cell receptor positive (TCR+) T lymphocytes may significantly contribute to the mycobacterial-specific synovial fluid response. We therefore examined the relationship of the T cell proliferative response to Mycobacterium tuberculosis antigens and the presence of gamma/delta TCR+ T cells employing several monoclonal antibodies. No consistent increase of gamma/delta TCR+ T cells was noted in inflammatory synovial fluids or tissues. Nonetheless, lymphocytes from the majority of the synovial fluids proliferated vigorously in response to water-soluble M. tuberculosis antigens. There was no relationship between the percentage of gamma/delta TCR+ T lymphocytes and the intensity of the proliferative response. In contrast, stimulation with whole mycobacterial organisms was capable of enriching the gamma/delta TCR+ cell population obtained from the peripheral blood of tuberculosis skin test positive normal controls and from some inflammatory synovial fluids. These observations do not support a role for mycobacteria reactive gamma/delta TCR+ synovial T lymphocytes in response to soluble mycobacterial antigens or in the local pathogenesis of inflammatory synovitis.

CD5+ B cells and CD4-8-T cells in neuroimmunological diseases

Using 2- and 3-colour FACS analysis we found increased levels of fetal-type CD5+ B cells and CD4-8- T cells in cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) and aseptic meningitis (AM) compared to control probands with muscular tension headache (TH). Similar differences were found for CD5+ B cells in peripheral blood, but at lower levels. CD4-8- T cells in blood exceeded those in CSF in all patient groups, with the exception of relapsing remitting MS, revealing the highest values in AM. There was a positive correlation between CD4-8- T cells and T cell receptor (TCR) gamma delta bearing T cells in blood and CSF. The double-negative T cells exceeded the TCR gamma delta T cells by about 1%. A positive correlation between CD5+ B cells and CD4-8- T cell level in CSF was found in MS and AM, but not in TH, nor in blood of any patient group. HLA-DR expression was lower in CD5+ B cells than in CD5- B cells. We conclude that fetal-type lymphocytes are enriched in CSF compartment of patients with inflammatory diseases of the central nervous system, irrespective of autoimmune mechanisms involved, but the function of CD5+ B cells is mainly to produce the autoantibodies.

T cell receptor delta diversity of freshly isolated T lymphocytes in rheumatoid synovitis

In some patients with rheumatoid synovitis the distribution of V delta gene families used by freshly isolated T lymphocytes from the synovial fluid and peripheral blood is different: peripheral blood T lymphocytes preferentially use the V delta 2 gene segment, whereas the majority of synovial fluid T lymphocytes use the V delta 1. The antigenic diversity of T cell receptor gamma/delta is mainly dependent upon base sequences in the V-J junction. In the present study we investigated whether the synovial fluid T lymphocytes expressing the V delta 1 gene segment were derived from a polyclonal or monoclonal expansion. The sequences encoding the V-J junctions of 11 cDNA clones derived from the synovium of two patients with chronic arthritis were determined. Our data demonstrate that the V delta 1 cDNA clones have different V-J junction sequences. This indicates that the V delta 1-expressing T cells found in the synovial compartment are polyclonally expanded.

T gamma delta cells and their subsets in blood and synovial tissue from rheumatoid arthritis patients

We have examined the frequencies of T gamma delta cells in blood, synovial fluids, and synovial membranes of patients with rheumatoid arthritis (RA) and in blood from age-matched controls. Immunocytochemical and immunohistochemical techniques were used with monoclonal antibodies BB3 and A13 to define a major and minor blood subset of T gamma delta cells respectively. Together, these antibodies identify the majority (if not all) of the peripheral blood T gamma delta cells. Significantly lower levels of T gamma delta cells were found in the blood of RA patients compared with controls, whilst higher but not significant numbers were found in the synovial fluids of paired samples. Scattered T gamma delta cells were found only in some synovial membranes with a distribution similar to the T alpha beta cells. Analysis of the two different T gamma delta-cell subsets indicated a ratio of BB3 to A13 of about 5:1 in control and RA blood. However, this ratio was less than 1:1 in the RA synovial fluids and membranes. The migratory nature of the A13+ cells could account for their predominance in these sites. The possible pathological significance of these cells in the rheumatoid synovial fluid and synovial membranes is discussed.

T gamma delta cells in juvenile rheumatoid arthritis and rheumatoid arthritis. In the juvenile rheumatoid arthritis synovium the T gamma delta cells express activation antigens and are predominantly V delta 1+, and a significant proportion of these patients have elevated percentages of T gamma delta cells

Using the anti-TcR gamma/delta-1 monoclonal antibody and flow cytometry, we examined the number of T gamma delta cells in paired samples of peripheral blood and synovial fluid or tissue from 24 children with juvenile rheumatoid arthritis (JRA), five adult patients with JRA, and 14 patients with rheumatoid arthritis (RA). No significant difference was found in the synovial compartment T gamma delta values compared with the blood in JRA, adult JRA, or RA patients. Nor was any significant difference found in the peripheral blood or synovial compartment T gamma delta values in any of the three patient groups compared with the peripheral blood of normal controls. However, seven of the children with JRA had very high T gamma delta values in the synovial compartment while none of the normal children had high T gamma delta values in the blood (P = 0.02, Fisher's exact test). This may indicate a possible separate JRA patient group with high T gamma delta levels in the synovial compartment. In six JRA patients further analysed for T gamma delta subpopulations, a significant predominance of V delta 1+ cells was found in the synovial compartment compared with the corresponding peripheral blood samples (P less than 0.05, Wilcoxon's signed test) and with peripheral blood of child controls (P less than 0.05, Mann-Whitney U test). In these six patients, the T gamma delta-cell expression of the very early activation antigen CD69 were significantly higher (P less than 0.05, Wilcoxon's signed test) in the synovial compartment compared with the peripheral blood. Synovial T gamma delta cells expressing HLA-DR and interleukin 2 receptors could also be detected, in contrast to the peripheral blood in which no T gamma delta cells expressing these antigens could be found. These data suggest that the synovial T gamma delta cells had been activated in vivo.

Synovial cells responding to a 65-kDa mycobacterial heat shock protein have a high proportion of a TcR gamma delta subtype uncommon in peripheral blood

We have analysed the ability of T cells from synovial fluid mononuclear cells (SFMC) and from peripheral blood mononuclear cells (PBMC) of inflammatory arthritic diseases to proliferate in response to mycobacterial antigens (65-kDa heat shock protein [hsp] of BCG, whole BCG) and to rat collagen type II. The SFMC demonstrated a significantly greater ability to respond to 65-kDa hsp of BCG, and to whole BCG, compared with PBMC from the same patients. With collagen type II, only a small proportion of the patients showed a proliferative response, although with this antigen also SFMC responded better than PBMC. There was no difference between SFMC and PBMC in the response to control antigen (tetanus toxoid), phytohaemagglutinin (PHA), or interleukin 2 (IL-2). A high proportion of cells in SFMC-derived short-term T-cell lines were of TcR gamma delta type, often exceeding the number of TcR gamma beta type. There was a significantly higher proportion of TcR gamma delta cells in the SFMC lines compared with the PBMC lines, and a large part of the TcR gamma delta cells in the SFMC cultures was CD8+. The SFMC lines had a high proportion of delta-TCS-1+ cells (V delta 1) among their TcR gamma delta cells, always exceeding the percentages of Ti gamma A+(V gamma 9) and BB3+ (V delta 2). In the PBMC lines, the distribution of TcR gamma delta subtypes was markedly different, with a Ti gamma A+/BB3+ population in the majority. These data argue for a different subpopulation distribution of TcR gamma delta cells in synovial fluid compared with peripheral blood of patients with inflammatory arthritic diseases.