In vitro mitogen stimulation of synovial fluid lymphocytes from rheumatoid arthritis and juvenile rheumatoid arthritis patients: dissociation between the response to antigens and polyclonal mitogens

How Rheumatoid Arthritis Can Result from Provocation of the Immune System by Microorganisms and Viruses

The pathogenesis of rheumatoid arthritis (RA), similar to development of a majority of inflammatory and autoimmune disorders, is largely due to an inappropriate or inadequate immune response to environmental challenges. Among these challenges, infectious agents are the undisputed leaders. Since the 1870s, an impressive list of microorganisms suspected of provoking RA has formed, and the list is still growing. Although a definite causative link between a specific infectious agent and the disease has not been established, several arguments support such a possibility. First, in the absence of a defined pathogen, the spectrum of triggering agents may include polymicrobial communities or the cumulative effect of several bacterial/viral factors. Second, the range of infectious episodes (i.e., clinical manifestations caused by pathogens) may vary in the process of RA development from preclinical to late-stage disease. Third, infectious agents might not trigger RA in all cases, but trigger it in a certain subset of the cases, or the disease onset may arise from an unfortunate combination of infections along with, for example, psychological stress and/or chronic joint tissue microtrauma. Fourth, genetic differences may have a role in the disease onset. In this review, two aspects of the problem of “microorganisms and RA” are debated. First, is there an acquired immune deficiency and, in turn, susceptibility to infections in RA patients due to the too frequent and too lengthy infections, which at last break the tolerance of self antigens? Or, second, is there a congenital deficiency in tolerance and inflammation control, which may occur even with ordinary infection frequency and duration?

BCG immunotherapy – from pathophysiology to clinical practice

Treatment with Bacillus Calmette-Guérin vaccine is mainly in use for superficial bladder cancer, for which it is given intravesically. Overall, this therapy is safe with only minor side effects. Arthritis secondary to such therapy has been rarely reported and usually responds well to NSAID treatment. The mechanisms leading to such a complication, as well as the clinical data, are discussed.

Bcg and autoimmunity: another two-edged sword

BCG immunotherapy for bladder carcinoma has been a long-standing treatment modality that has proved itself efficient and safe. Most of the side-effects of this treatment are minor and of short duration. There have been, nevertheless, several reports regarding more severe and long-term complications of BCG therapy-namely inflammatory arthritis, and occasionally systemic autoimmune manifestations. Here, we present four cases of patients who received intravesical instillation with BCG for bladder carcinoma and developed long-standing inflammatory arthritis. One of these patients developed Reiter's syndrome. We also refer to the possible immune mechanisms by which BCG can trigger arthritis, as well as to the link between mycobacterial infection, BCG immunotherapy and autoimmunity.

Decreased expression of signal-transducing CD3 zeta chains in T cells from the joints and peripheral blood of rheumatoid arthritis patients

Although T cells from patients with rheumatoid arthritis (RA) have previously been determined to have poor proliferative responses to a variety of stimuli, the underlying mechanism is not known. We have investigated the expression of the signal-transducing zeta molecule in subsets of T cells and natural killer (NK) cells derived from the peripheral blood mononuclear cells (PBMC) and synovial fluid mononuclear cells (SFMC) of RA patients using quantitative flow cytometry, Western blot analysis and immunohistochemistry. A decrease of zeta expression was apparent in all investigated lymphocyte subsets from the PBMC and SFMC of RA patients, as compared to the corresponding subsets from healthy age- and sex-matched controls. A less pronounced reduction of cell surface-located CD3 epsilon, CD4 and CD8 was also located in T cells from SFMC as compared to PBMC from RA patients. Biochemical demonstration of the low or absent CD3 zeta in PBMC from patients with RA was achieved by Western blot analysis. Immunohistochemical staining and image analysis also confirmed the low expression of zeta chains in synovial tissue of RA patients. The possibility that the decreased expression of zeta and of immune functions of T cells from RA patients may be related to the presence of free oxygen radicals, as we have previously reported in cancer patients, should be considered.

Juvenile rheumatoid arthritis-like polyarthritis in chromosome 22q11.2 deletion syndrome (DiGeorge anomalad/velocardiofacial syndrome/conotruncal anomaly face syndrome)

OBJECTIVE

To investigate the association of polyarthritis and chromosome 22q11.2 deletions.

METHODS

Eighty patients with chromosome 22q11.2 deletion syndrome followed up at The Children's Hospital of Philadelphia were examined for evidence of arthropathy or arthritis. Patients with chromosome 22q11.2 deletion syndrome and polyarthritis underwent laboratory evaluations of immunologic function to determine the relationship of their immunodeficiency to the polyarthritis.

RESULTS

The prevalence of polyarthritis in patients with chromosome 22q11.2 deletion syndrome was markedly increased over the prevalence of polyarticular juvenile rheumatoid arthritis (JRA) in the general population. All 3 patients with polyarthritis had evidence of impaired T cell function. Two of the patients with polyarthritis also had IgA deficiency.

CONCLUSION

The chromosome 22q11.2 deletion syndrome represents a primary T cell disorder which can be associated with a JRA-like polyarthritis. All 3 patients with polyarthritis had evidence of more extensive immunoregulatory derangements than those typically seen in patients with chromosome 22q11.2 deletion, and these derangements may have predisposed to the development of polyarthritis.

Rheumatoid inflammatory T-cell clones express mostly Th1 but also Th2 and mixed (Th0-like) cytokine patterns

This study was performed in order to characterize whether T cells from rheumatoid synovial inflammation belong to the Th1- or Th2-like functional subsets. Cytokine production was studied in 26 CD4+ alpha beta+ and 2 CD8+ alpha beta T-cell clones from the synovial fluid, the synovial membrane and peripheral blood of 5 patients. Fifteen of the CD4+ clones were raised against various mycobacterial antigens and 11 CD4+ clones and 2 CD8+ clones were raised unspecifically using PHA and/or IL-2. The specificities of these clones are not known. In the mycobacterial antigen-specific group, all CD4+ alpha beta T-cell clones produced IFN-gamma at high levels, while the production of IL-4 was generally absent or low (< 1 ng/ml), consistent with a Th1-like profile. Some of these clones, however, also produced various amounts of IL-10 which has been regarded as a Th2 product but can be produced also in lower amounts by Th1 cells. One HSP-65-specific clone produced levels of IL-4 and IL-10 in the same order as that of IFN-gamma, thus appearing to be Th0-like. Among the 11 unspecific CD4+ clones, 7 showed a Th1-like pattern but with lower levels of IFN-gamma than the antigen-specific clones. However, three clones did not produce any IFN-gamma activity but produced IL-4 and one of them also produced distinct amounts of IL-10, compatible with a Th2-like pattern. In addition, one of the clones also showed an almost equally strong IFN-gamma and IL-4 production, thus most likely representing a Th0-like clone.

Heterogeneity of the TCR repertoire in synovial fluid T lymphocytes responding to BCG in a patient with early rheumatoid arthritis

T lymphocytes have been implicated in the pathogenesis of rheumatoid arthritis. Interestingly, many of the activated T cells isolated from the synovial fluid of individuals with rheumatoid arthritis react with antigens from Mycobacterium tuberculosis or BCG. This response is seen to a much lesser extent in the peripheral blood of these patients. To investigate the nature of the T-cell response to BCG in RA, we isolated T cells from the synovial fluid of a patient with early-stage rheumatoid arthritis, stimulated them with BCG and cloned by limiting dilution. Staining with monoclonal antibodies specific for different V beta gene families revealed a statistically significant greater proportion of synovial-derived T-cell clones expressing the V beta 8 gene family product compared with peripheral blood clones. While the antigen specificity of some of the clones could not be determined, several of the clones displayed distinct antigen reactivities. Sequencing the TCR beta chain genes of these T cells suggested that although the V beta 8 gene products appeared to be over-represented in these BCG-specific clones, each clone utilized distinct J beta gene segments and used N segment addition to different extents. In addition, no common motifs were identified in the beta chain CDR3s of the clones sequenced. Analysis of bulk cultured BCG-specific SF T cells and unstimulated peripheral blood T cells for V beta 8 gene expression also revealed a large amount of diversity within the CDR3 region. Thus, the T-lymphocyte response to BCG in this patient with early rheumatoid arthritis appears to be quite heterogeneous.

Heat shock (stress) proteins and autoimmunity in rheumatic diseases

The rheumatic diseases (RDs) are characterized by acute and chronic inflammation, and autoimmunity plays a major role in their pathogenesis. RDs are for the most part of unknown etiology, but recent evidence indicates that heat shock or stress proteins (HSPs) may have an important role in the etiology/pathogenesis of RDs. HSPs are produced by prokaryotic and eukaryotic cells and are grouped according to molecular weight. Phylogenetically, HSPs are very old and are remarkably conserved molecules in evolution from bacteria to humans. HSPs are induced by a variety of cellular stresses in addition to heat; cognates are expressed constitutively and are essential in a number of normal functions. Some HSPs serve as molecular chaperones, the latter defined as proteins that mediate folding of other polypeptides and either promote their assembly into oligomeric structures or disassemble the final product. Conservation of structure and function of many HSPs may provide a link between immunity to infection and the autoimmune features of RDs. Evidence is reviewed from clinical and laboratory observations that diverse microbial agents, including viruses, bacteria, and parasites, may have putative roles in the development and pathogenesis of some RDs. HSPs also are discussed in relation to the major histocompatibility complex, HLA antigens, and disease associations and how they may alter the balance between tolerance and autoimmunity. Studies are reviewed that are supportive or nonsupportive of the concept of microbial infection associated with autoimmunity; individuals first react to microbial immunizations or infections with enhanced cellular/humoral responses to the agent's HSPs. With the enhanced immune response, cross-reactivity may occur with an HSP of the stressed host because of structural similarities to the microbial HSP. If all of these events occur, the host's homologous HSP or stressed cells now become true autoantigen(s). This sequence has implications for the etiology of immune-mediated RDs, the concept of epitope sharing, and the accompanying autoimmunity. A recurring theme emphasized in some reports to understand better the role of HSPs in autoimmunity is the need to select patients with early-onset disease. A minor subpopulation of T lymphocytes express a CD3-associated T-cell receptor (TCR) heterodimer composed of gamma and delta polypeptide chains. The gamma delta + T cells have several unique features. When analyzed by the polymerase chain reaction, lymphocytes with TCR-gamma delta appear to reflect the polyclonal expansion of preexisting gamma delta clones. They are found in peripheral lymphoid tissue in very low percentage (< 5%) but may represent the majority of T cells within epithelial tissue.(ABSTRACT TRUNCATED AT 400 WORDS)

Responses of synovial fluid and peripheral blood mononuclear cells to bacterial antigens and autologous antigen presenting cells

The specificity of T cells in the inflamed joints of patients with rheumatoid arthritis (RA) has been the subject of much study. Bacterial antigens are suspect in the aetiology of rheumatic diseases. The responsiveness of the mononuclear cell fraction of peripheral blood and synovial fluid of patients with RA and of patients with rheumatic diseases other than RA to bacterial antigens such as cell wall fragments of the anaerobic intestinal flora, cell wall fragments of Streptococcus pyogenes, intestinal flora derived peptidoglycan polysaccharide complexes, the 65 kilodalton protein of Mycobacterium tuberculosis, and muramyldipeptide was investigated. No significant difference in response was found to all these bacterial antigens in the synovial fluid of patients with RA compared with the responses in patients with other rheumatic diseases. The highest responsiveness in the synovial fluid of the patients with RA was to the streptococcal cell wall fragments and to the 65 kilodalton protein. Higher responses to several bacterial antigens in the synovial fluid of patients with RA were found compared with peripheral blood from the same patient group. The antigen presenting cell population of the synovial fluid in patients with RA and the patients with other rheumatic diseases was found to be stimulatory for autologous peripheral blood T cells even in the absence of antigen. This suggests an important role for the synovial antigen presenting cell in the aetiology of inflammatory joint diseases.

Demonstration of CD13/aminopeptidase N on synovial fluid T cells from patients with different forms of joint effusions

Cytofluorometric analysis was performed to characterize the immunophenotype of lymphocytes of the synovial fluid (SF) and the peripheral blood (PB) from patients suffering from juvenile chronic arthritis (JCA) or rheumatoid arthritis (RA). The most obvious difference could be found in expression of the surface protease aminopeptidase N (AP N/CD13). Whereas monoclonal antibodies specific to CD13 failed to reveal surface expression on lymphocytes of the PB; 63 +/- 15% of SF T cells gave positive staining for CD13 using Leu-M7. No correlation between CD13 expression and joint disease could be found in patients who had different types of inflammatory joint effusions. CD13 expression of T cells was also found in synovial tissue and inflammatory serous cavity effusions. Fixation of T cells revealed the presence of intracellular CD13 antigen already located in the PB T cells of healthy individuals. Induction of CD13 expression on PB T cells could be demonstrated after incubation with Con A/IL-2 or SF from patients with RA. Our findings suggest a role for AP N as a new activation-associated molecule of T lymphocytes.

Peptide recognition, T cell receptor usage and HLA restriction elements of human heat-shock protein (hsp) 60 and mycobacterial 65-kDa hsp-reactive T cell clones from rheumatoid synovial fluid

A commonly held postulate regarding the etiology of rheumatoid arthritis (RA) is that of antigenic mimicry. Recent interest has focused on the mycobacterial 65-kDa heat-shock protein (hsp) as a putative causal agent. The 65-kDa hsp has over 40% sequence homology with the human hsp 60, and elevated synovial T cell responses to both antigens have been demonstrated in RA and juvenile rheumatoid arthritis patients. Such T cells should, therefore, be specific for shared epitopes on the two antigens. To investigate this, we screened synovial fluid mononuclear cells from two early RA patients with peptides of the 65-kDa hsp which have the greatest homology with the human hsp 60. We also raised a panel of T cell clones from one of the patients with the 65-kDa hsp. The synovial T cell population from both patients and one of the T cell clones recognized a peptide representing the amino-acid sequence 241-255. This clone also responded to the peptide of the equivalent human sequence, and was restricted by HLA-DQ. A second T cell clone recognized an adjacent epitope (amino acid sequence 251-265) which is also highly homologous with the human sequence, but this clone was restricted by HLA-DR. The clones utilized different V beta gene segments but the same D beta and J beta gene elements, and both exhibited specific cytotoxicity against autologous antigen-pulsed macrophages. Our findings, therefore, do not disagree with the postulate that autoimmune disease could possibly be triggered by bacterial epitopes with homology to self protein. However, it is also noted that there are alternative interpretations of this data.

Mycobacteria and human heat shock protein-specific cytotoxic T lymphocytes in rheumatoid synovial inflammation

OBJECTIVE

To study the cytotoxic capacity of mycobacteria-specific T lymphocyte lines and clones from sites of inflammation in patients with rheumatoid arthritis (RA). We also studied antigen specificity, surface phenotype, expression of T cell receptors (TCR), and HLA restriction.

METHODS

Autologous macrophages (M phi) from the synovial membrane (SM), synovial fluid (SF), or peripheral blood (PB) were used as target cells in cytotoxicity assays.

RESULTS

All SM and SF cell lines tested thus far have shown specific lysis of the autologous M phi from SM or PB that had been pulsed with BCG (bacillus Calmette-Guerin), but no cytotoxicity when the targets were pulsed with irrelevant antigens such as tetanus toxoid and Chlamydia. Both CD4+ and CD8+ cells were shown to be involved in the specific cytolysis. The majority of the cytotoxic T lymphocyte (CTL) lines were TCR alpha/beta + cells. However, both TCR alpha/beta + and TCR gamma/delta + clones (TCR delta 1+) from one RA patient showed antigen-specific lysis. Antigen-specific recognition by a number of CTL lines and clones generated from SF and SM was restricted by HLA-DR molecules. Two Mycobacterium bovis 65-kd heat shock protein (HSP)-specific TCR alpha/beta + SF T cell clones also lysed M phi that had been pulsed with a recombinant human 65-kd HSP.

CONCLUSION

Joint inflammation and destruction might be partly attributable to a cross-reaction of mycobacteria-induced cytotoxic T cells with self HSP.

Activation of synovial fluid T lymphocytes by 60-kd heat-shock proteins in patients with inflammatory synovitis

OBJECTIVE

Synovial fluid lymphocytes from patients with rheumatoid arthritis and with other forms of inflammatory synovitis demonstrate enhanced proliferative responses to Mycobacterium tuberculosis antigens, in particular, the 65-kd heat-shock protein. There is a high degree of homology between the human and the mycobacterial 60-kd family of heat-shock proteins. These studies were performed to determine if the enhanced response to the mycobacterial 65-kd heat-shock protein was due to cross-reactivity of an immune response generated against the human homolog.

METHODS

These studies were performed by in vitro culture of isolated synovial fluid mononuclear cells with crude and purified antigens.

RESULTS

The synovial fluid lymphocytes of a majority of patients with rheumatoid arthritis recognized the mycobacterial 65-kd heat-shock protein, as evidenced by T cell proliferation. In contrast, only 18% of all samples tested responded to a highly purified recombinant human 60-kd heat-shock protein. With only one exception, proliferative responses to the mycobacterial antigen were stronger than those to the human homolog. The proliferative responses generated against mycobacterial 65-kd heat-shock proteins from different sources were highly correlated.

CONCLUSION

The findings suggest that the enhanced proliferative response to the mycobacterial 65-kd heat-shock protein noted in most patients with rheumatoid arthritis and other forms of inflammatory synovitis is not due to cross-reactivity of an immune response directed against the human heat-shock protein.

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.

Recognition of human 60 kD heat shock protein by mononuclear cells from patients with juvenile chronic arthritis

A postulated mechanism for autoimmune disorders is that the immunoreactivity develops against bacterial antigens which show a high degree of sequence homology with mammalian proteins. The mycobacterial 65 kD heat shock protein (hsp) has been implicated in several forms of arthritis. Substantial amounts of the human 60 kD homologue (hsp60) were produced by insertion of the gene into Escherichia coli. To investigate the hypothesis that T-cell reactivity is directed against the endogenous hsp, T-cell proliferation of synovial-fluid and peripheral-blood mononuclear cells in response to hsp60 was studied in samples from six patients with juvenile chronic arthritis (JCA) and nine adult patients with rheumatoid arthritis (RA). There was no T-lymphocyte proliferative response to purified fractions of hsp60 in mononuclear cells from RA patients or healthy children and young adults. However, both synovial-fluid and peripheral-blood mononuclear cells from JCA patients showed substantial proliferative responses. There was a significant correlation between the stimulation indices for human hsp60 and for mycobacterial hsp65 (r = 0.948, p less than 0.02). A similar correlation for hsp60 and mycobacterial hsp70 did not achieve significance. Immunohistochemistry showed that hsp65 and hsp70 homologues were expressed in the synovial membrane in these patients but not in controls. These findings suggest a sequence of events in which hsps become expressed during synovial inflammation and function as autoantigens. In JCA this may be manifested by specific T-cell reactivity which apparently is lost in the more bone-eroding and non-remitting adult disease.

Heat-shock proteins as immunogenic bacterial antigens with the potential to induce and regulate autoimmune arthritis

Heat-shock proteins are ubiquitous and surprisingly immunogenic bacterial proteins. Due to their extensive evolutionary conservation, development of immune reactivity directed at hsp is expected to jeopardize the maintenance of tolerance for "self". The experimental model of adjuvant arthritis in rats has been illustrative in this respect. In this model disease is induced by immunization to mycobacteria, and by T-cell cloning it appeared that T cells with specificity for the 180-188 sequence of the mycobacterial hsp65 were capable of both inducing the disease or inducing resistance to the disease. Although the exact molecular mimicry relationship of this 180-186 epitope with the proteoglycan moiety of cartilage remains to be elucidated, the crucial significance of hsp65 immunity has been substantiated further, not only in adjuvant arthritis, but also in other models of experimentally induced arthritis. Development of disease is seen to coincide with development of hsp65 reactivity, and in AA to the 180-186 epitope in particular. There is now experimental evidence that responses to hsp65 are subject to regulatory T-cell control, and that such regulatory control may explain the observations that preimmunization with hsp65 induces protection against subsequent development of arthritis. In human arthritis, responses to hsp65 have been seen to occur at the level of synovial fluid-derived T lymphocytes. Especially, in children with juvenile chronic arthritis such responsiveness was seen to be directed at the endogenous "self" hsp60, as it was also found to be expressed at a raised level in the synovial lining cells. Altogether, both from the experimental models and from the human disease, evidence is being collected for hsp65 as a critical antigen which has, in the experimental models, the potential of inducing protective regulatory T-cell control. AA has now offered us some initial possibilities for exploiting this feature of hsp65 in inducing remission of disease. We may hope that, ultimately, such specific immunological intervention in disease will also become a reality in the management of human autoimmune arthritis. The exploitation of the regulatory control mechanisms that normally contain the dangerously autoimmune reactive elements in the system seems to be most attractive for such a purpose. We should not try to modify the outside non-self; however, we should use our understanding of the mechanisms involved in order to stimulate the immune system of the unfortunate to resume control over the management of responses directed at the endogenous "self". It is possible that further analysis of the role of hsp65 in arthritis will lead to such necessary understanding.

T cell activation by mycobacterial antigens in inflammatory synovitis

To define which mycobacterial antigens were responsible for the activation of synovial fluid T lymphocytes, acetone-precipitated Mycobacterium tuberculosis (AP-MT) antigens were separated into five fractions following polyacrylamide gel electrophoresis and added to the mononuclear cell cultures of patients with inflammatory synovitis. Fractions 2 (50 to 70 kDa) and 5 (less than 28 kDa) resulted in significantly more proliferation than that of fractions 1, 3, and 4. The response to a purified mycobacterial 65-kDa heat shock protein (hsp), which migrated in fraction 2, was highly correlated (r = 0.89, P less than 0.001) with the response to the crude AP-MT. The proliferative response to a different hsp. the Escherichia coli DnaK, by synovial fluid lymphocytes was marginal. Analysis of the synovial fluid T cell response to mycobacterial culture filtrates by T cell Western blotting revealed dominant responses to antigen(s) in the range of 31 to 21 kDa in each responding patient, although no other consistent pattern of T cell activation was noted. Three lines of evidence suggested that the response to the low molecular weight fractions was directed against degradation fragments of the 65-kDa protein. These observations suggest that the activation of T lymphocytes obtained from inflammatory synovial fluids by crude mycobacterial antigens was due in large part to recognition of the 65-kDa mycobacterial hsp.

Mechanism of T-cell activation by mycobacterial antigens in inflammatory synovitis

Earlier studies demonstrated enhanced proliferative responses to an acetone precipitable Mycobacterium tuberculosis (AP-MT) antigenic complex by T lymphocytes from the synovial fluid, compared with the peripheral blood, of patients with inflammatory synovitis, including rheumatoid arthritis. In contrast, decreased proliferation and interleukin 2 (IL-2) production in response to mitogens by synovial fluid lymphocytes from patients with rheumatoid arthritis has been demonstrated. In order to determine if IL-2 was produced in response to AP-MT, the peripheral blood and synovial fluid of patients with inflammatory arthritis were analysed by measuring proliferation and IL-2 production in response to AP-MT and tetanus toxoid. A reduction of IL-2 production relative to proliferation was observed in some, but not all, synovial fluids of patients who responded to the AP-MT. Nevertheless, antibodies to IL-2 as well as interleukin 4 (IL-4), significantly inhibited proliferation of synovial fluid lymphocytes by AP-MT. There was no inhibition by antibodies to interleukin 6 (IL-6). We conclude that AP-MT induced proliferation by synovial fluid lymphocytes is mediated by both IL-2 and IL-4.

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.

Proliferative response of synovial fluid and peripheral blood mononuclear cells to arthritogenic and non-arthritogenic microbial antigens and to the 65-kDa mycobacterial heat-shock protein

Cellular immune responses to microbial antigens have been implicated in the pathogenesis of some forms of arthritis including reactive arthritis, Reiter's syndrome, ankylosing spondylitis and rheumatoid arthritis. We investigated the proliferative T cell responses of paired peripheral blood (PB) and synovial fluid (SF) mononuclear cells (MC) to so-called arthritogenic bacteria (Yersinia enterocolitica and Salmonella typhimurium), to control antigens, such as Candida albicans, mumps virus and purified protein derivative, to the recombinant mycobacterial 65-kDa heat-shock protein (hsp 65) and the mitogen phytohemagglutinin (PHA) in 16 patients with different inflammatory rheumatic diseases. The [3H]thymidine uptake of unstimulated cells (medium control) as well as the proliferative response to the different antigens tested was markedly increased in SFMC irrespective of the underlying rheumatic disease. In contrast, mitogenic stimulation was decreased in SFMC. The proliferative response to the hsp 65 correlated significantly with the responses to Yersinia, Salmonella and Candida. These results may reflect an enhanced function of SF antigen-presenting cells, different functional properties and subset distributions of PB and SF T cells with a preferential accumulation of helper-inducer/memory T cells or a maintenance of an ongoing immune response by T cells cross-recognizing self epitopes such as epitopes located on the hsp 65. Thus, care should be taken in the interpretation of SF T cell responses to microbial antigens as diagnostic tools in arthritis.

Depressed T-cell reactivity to recall antigens in rheumatoid arthritis

Reactivity toward soluble recall antigens (Candida albicans, cytomegalovirus, herpes simplex, streptokinase-streptodornase, and influenza) was determined in cultures of peripheral blood mononuclear cells from 41 rheumatoid arthritis patients (with clinically active as well as inactive disease) and from 28 controls. In the group with clinically active rheumatoid arthritis we found an increased incidence of "anergy," defined as nonreactivity to three or more antigens. In an attempt to explain this decreased antigen reactivity, the latter was correlated with peripheral blood lymphocyte subsets, as defined by two-color immunofluorescence with a panel of eight monoclonal antibodies. We found a significantly lower number of memory T4 cells (CD4+CD45RA-) and a significantly higher number of the CD3-CD57+ (nonspecific suppressor) cells and of CD3-CD56+/CD16+ (natural killer) cells in anergic RA patients. In the total group of rheumatoid arthritis patients, the antigen reactivity correlated positively with the percentage of memory T4 cells. Antigen reactivity was negatively correlated with the percentage of CD3-CD57+ cells and of the CD3- natural killer cells in peripheral blood. Our data suggest that a decrease in memory T4 cells and an increase in nonspecific suppressor cells may contribute to the impaired cellular immune function in peripheral blood of rheumatoid arthritis patients.

Antigenic specificity of rheumatoid synovial fluid lymphocytes

The majority of rheumatoid arthritis (RA) synovial fluid lymphocytes (SFL) demonstrate markers that are suggestive of prior activation. While the mechanism(s) responsible is unknown, prior studies have suggested that certain Mycobacterium tuberculosis (MT) antigens may preferentially activate SFL in vitro. We therefore examined the ability of RA SFL to respond to purified protein derivative and an acetone-precipitable MT antigenic complex (AP-MT) and compared this with the responses by peripheral blood lymphocytes (PBL). The responses were contrasted with those elicited with tetanus toxoid (TT) and mitogenic anti-CD3. In patients with RA, the SF proliferative responses to both TT and anti-CD3 were reduced compared with responses by PB. In contrast, the SF response to purified protein derivative was maintained, and that to AP-MT was significantly increased, compared with PB. SF responses to AP-MT antigens were significantly greater than those to TT. The AP-MT activation of T lymphocytes from RA SF was characterized by an earlier peak proliferative response than that noted with matched PB. AP-MT responsiveness was not restricted to HLA-DR4 positive patients. These observations suggest that an epitope(s) contained within the MT complex of antigens, and enriched in the AP-MT complex, may be important in maintaining the chronic inflammation in at least some patients with RA.

A functional study of purified CD4+ and CD8+ cells isolated from synovial fluid of patients with rheumatoid arthritis and other arthritides

The purpose of this investigation was to study purified synovial fluid (SF) CD4+ and CD8+ cells from patients with rheumatoid arthritis (RA) and other inflammatory joint diseases (non-RA) with respect to the proliferative response to mitogens and recombinant interleukin 2 (rIL-2). Highly purified cell subsets were isolated by an immunomagnetic technique, and spontaneous proliferation as well as proliferative reSponses to rIL-2 and a combination of phytohaemagglutinin (PHA) and phorbol myristate acetate (PMA) (to substitute for accessory cells) were measured. Some patients had SF CD4+ and/or CD8+ cells with moderately increased spontaneous proliferation, but only the CD4+ cells of the two patient groups differed significantly from the peripheral blood (PB) T-cell subsets of healthy individuals who served as controls. The response to rIL-2 was variable but generally low, although about 50% of the CD4+ and 20% of the SF CD8+ cells of both patient groups expressed the Tac antigen. The response to PHA/PMA was significantly lower for RA SF CD4+ cells than for non-RA SF CD4+ cells, which again was lower than for normal PB CD4+ cells. SF CD8+ response to PMA/PHA by both groups of patients was somewhat decreased, but not significantly lower than in the controls. Thus, the CD4+ cells seemed functionally more deviant than the CD8+ cells in both patient groups, but the abnormality was most pronounced in the RA group. The results demonstrate that the previously reported diminished response to mitogens by SF mononuclear cells is present even when SF CD4+ cells are cultured alone. This indicates that these T cells have a reduced response, probably because of prior activation.

Isolation of CD4- CD8- mycobacteria-reactive T lymphocyte clones from rheumatoid arthritis synovial fluid

The majority of peripheral T cells express a heterodimeric, alpha/beta T-cell receptor, which recognizes specific antigenic peptides bound to self major histocompatibility complex (MHC) molecules, and either the CD4 or CD8 surface markers. An additional subset of T cells, whose physiological function is unknown, express a distinct CD3-associated receptor composed of gamma and delta chains. This subset includes cells lacking both CD4 and CD8 surface markers, which may be involved in autoimmunity. The recognition specificity of the gamma/delta receptors is not well characterized and has been defined in only one case to date, a murine cell line which shows MHC-linked specificity. In this report, we describe the isolation of CD4- CD8-, gamma/delta TCR bearing T cell clones from the synovial fluid of a rheumatoid arthritis patient. These T cell clones respond specifically to mycobacterial antigens without MHC restriction.

B-cell growth-promoting activity in supernatants from CD4+ cells from synovial fluid and peripheral blood of patients with rheumatoid arthritis and other inflammatory arthritides

The purpose of this study was to compare CD4+ cells from peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis with regard to mitogen-induced production of B-cell growth-promoting activity. CD4+ cells were isolated by a direct immunomagnetic technique and supernatants from both unstimulated and mitogen-stimulated CD4+ cells were studied. B-cell growth-promoting activity was assayed using highly purified B cells obtained from peripheral blood of healthy individuals. The indicator B cells were isolated by an indirect immunomagnetic technique and solid-phase anti-mu was used for activation of the B cells. Supernatants of unstimulated CD4+ cells from SF and PB did not contain B-cell growth-promoting activity, while usually high levels of B-cell growth-promoting activity were detected in the supernatants from mitogen-stimulated cultures. There was no significant difference in the B-cell growth-promoting activity level between supernatants from SF CD4+ and patient PB CD4+ cells, nor was there any significant difference between SF CD4+ and control PB CD4+ supernatants. The results indicate that the CD4+ cells in the SF have a normal potential for producing B-cell growth-promoting activity.

Tuberculous rheumatism (Poncet's disease) in a child

A 2-year-old boy who had increasing difficulty walking and had large, warm, sterile knee and ankle effusions was found to have active vertebral tuberculosis and a large prevertebral abscess. Lymphocyte proliferation assays demonstrated increased purified protein derivative-induced reactivity of synovial fluid lymphocytes compared with peripheral blood lymphocytes. The arthritis responded rapidly to antituberculous and antiinflammatory drugs. This patient's disease represented an example of tuberculous rheumatism (Poncet's disease).

Increased helper inducer and decreased suppressor inducer phenotypes in the rheumatoid joint

Cells isolated from the joints of patients with rheumatoid arthritis (RA) exhibit functional immune abnormalities, such as diminished suppressor activity, depressed response to mitogens, and enhanced immunoglobulin production. We sought to characterize the T lymphocyte subsets in the synovial fluid (SF) and peripheral blood (PB) of RA patients in an attempt to clarify the mechanism(s) responsible for these functional immune abnormalities. We used dual-immunofluorescence staining techniques with several combinations of monoclonal antibodies, including anti-4B4 and anti-2H4, which define, respectively, the helper inducer and suppressor inducer subsets of CD4+ (Leu-3+ and T4+) cells. Mononuclear cells from normal PB (n = 9), RA PB (n = 6), and RA SF (n = 9) were analyzed, after staining, by flow cytometry. We observed a significant increase (P less than 0.0002) in the number of cells bearing the helper inducer phenotype (CD4+, 4B4+), and a significant decrease (P less than 0.0002) in the number of cells bearing the suppressor inducer phenotype (CD4+, 2H4+), in RA SF compared with the levels in PB from RA patients or normal control subjects. We also observed that the CD8+, 2H4+ subset was significantly decreased (P less than 0.0001) in SF compared with that in PB. There was no significant difference in the lymphocyte subset levels in PB from RA patients and from normal subjects. These observations may account, in part, for the reduced suppressor activity, the poor response to mitogens, and the autologous mixed lymphocyte reaction, as well as the enhanced production of Ig and rheumatoid factor, that are observed in the rheumatoid joint.

T-cell helper activity and B-cell function of synovial and blood lymphocytes from patients with rheumatoid arthritis or other forms of chronic arthritis

The helper effect of T cells on B-cell immunoglobulin (Ig) responses induced by pokeweed mitogen (PWM) or purified protein derivative of tuberculin (PPD) was studied in lymphocytes from synovial fluid (SF) and blood of nine patients with rheumatoid arthritis (RA) and eight patients with other forms of chronic arthritis. In PWM cultures the helper effect of SF T cells on Ig responses (IgG, IgM, IgA) of autologous and allogeneic blood B cells was lower than that of blood T cells (P less than 0.01). This decrease was more pronounced in patients with RA than in patients with non-RA. In PPD cultures no significant difference was found between the helper effect of SF T cells and blood T cells on the Ig responses of allogeneic blood B cells or on the IgG response of autologous blood B cells, whereas the helper effect of SF T cells on the IgM and IgA responses of autologous blood B cells was decreased. The Ig responses to PWM or PPD in cocultures of autologous blood B and T cells were not significantly different between patients and healthy controls. The PWM- and PPD-induced Ig responses of SF B cells were lower than those of blood B cells when cocultured with autologous blood T cells. SF B cells produced IgG but usually little IgM and IgA. Thus there was a dysfunction of SF B cells and of SF T cells in a PWM-driven system, but a fairly good helper function of SF T cells in a PPD-driven system.

T lymphocytes of rheumatoid arthritis patients show augmented reactivity to a fraction of mycobacteria cross-reactive with cartilage

An acetone-precipitable fraction of Mycobacterium tuberculosis cross-reacts with human cartilage. Immune responses to this antigen were assessed in 34 patients with rheumatoid arthritis, 16 patients with degenerative joint disease, and 15 healthy controls. The RA patients differed from the other two groups in having more pronounced T lymphocyte responses to the antigen; their serum antibody levels were not higher. The responses of RA patients varied with duration of disease. In the first year (7 patients) T lymphocyte reactivity was increased in the synovial exudates of affected joints but not in peripheral blood, whereas the 19 with disease of 1-10 years' duration showed high reactivity in peripheral blood; in the 8 with disease for more than 10 years, lymphocyte reactivity did not differ from that in the patients with degenerative joint disease or the healthy controls. The observation that the three groups did not differ in their responses to streptococci and a T-cell mitogen indicates that reactivity of the RA patients to the mycobacterial fraction was specific. These results raise the possibility that bacterial antigens cross-reactive with cartilage proteoglycans may be relevant to the pathogenesis of RA.

Cell-mediated immunity in rheumatic disease

Rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis are the three most common systemic rheumatic diseases in which disordered immune function is thought to play a pathogenetic role. Each disease has different and characteristic abnormalities of the cellular immune system. In rheumatoid arthritis the identified abnormalities of immunoregulation are largely limited to specific antigens: Epstein-Barr virus and collagen. Systemic lupus erythematosus is characterized by exuberant B-cell activity with exaggerated humoral response, a diversity of autoantibodies, non-antigen-specific loss of suppressor cell function, and general suppression of cell-mediated immunity. In systemic sclerosis systemic defects of cellular and humoral immune function are mild, but the release of lymphokines and monokines at sites of inflammatory lesions is thought to be important in the pathogenesis of the disease. Similar immune cell-connetive tissue cell interactions are probably important in the propagation of rheumatoid synovitis. Thus, despite the many shared clinical and serologic features of these diseases as well as the presence of many patients who have clinically overlapping features of more than one of these entities, the immune defects and the immunopathogenesis of these disorders appear to be distinct.

Demonstration of a helper factor(s) with T-cell-replacing activity in synovial fluid

Cell-free synovial fluid (SF) obtained from patients with rheumatoid arthritis contains a helper factor(s) capable of augmenting the generation of plaque-forming cells (PFC) in pokeweed mitogen (PWM)-stimulated normal peripheral blood mononuclear cells (PBMC). This helper factor behaves like a polyclonal B-cell activator, in that it triggers the formation of IgM, IgG, and IgA PFC. However, SF has little or no effect on the proliferation of PWM-activated PBMC. Furthermore, SF was capable of replacing T cells for PWM-induced differentiation but not proliferation of enriched human blood B lymphocytes. No helper factor or T-cell-replacing activity was found in SF from patients with traumatic synovitis. Fractionation of SF containing helper activity on staphylococcal protein A column indicated that the activity is induced by biologically active molecules distinct from materials that preferentially bind to protein A such as IgG immune complexes. We conclude that the present activity has striking similarities to the recently described B-cell differentiation factor that is produced by specifically activated T-cell lines in vitro.

Cytotoxic anti-T cell antibodies in children with juvenile rheumatoid arthritis

The object of this investigation was to determine the prevalence of anti-T cell antibodies in 66 children with various connective tissue diseases. Anti-T cell antibodies were found in 43/44 juvenile rheumatoid arthritis (JRA) patients (mean cytotoxicity 15.0%) and in 10/10 children with systemic lupus erythematosus (mean cytotoxicity 20.0%), but in only 1/15 normal controls and in none of 12 children with other arthritides. There was no significant difference in mean percent cytotoxicity among the JRA subclasses. In the JRA patients, the percent cytotoxicity was positively correlated with the erythrocyte sedimentation rate (P = 0.01), but not with the presence or absence of rheumatoid factor, antinuclear antibodies, or immune complexes. The sera of 3 JRA patients repeatedly inhibited the stimulation of normal lymphocytes by mitogens and antigens by 47-99% (measured by the incorporation of 3H-thymidine into DNA) when added to the culture system in the first 24 hours; normal sera did not. Sera from patients with JRA have increased reactivity with mitogen-activated lymphocytes and T cells compared with unstimulated cells as determined by flow cytometry. The expression of the "JRA antigen" requires protein synthesis but not DNA synthesis or cell division. We conclude that the majority of patients with active JRA have cytotoxic anti-T cell antibodies and that in selected patients, these antibodies may play a role in regulation of the immune response.

Spontaneous and induced immunoglobulin secretion by synovial fluid B lymphocytes in rheumatoid arthritis

The functional properties of B lymphocytes in synovial fluid (SF) from patients with rheumatoid arthritis (RA) were analysed by means of a reverse haemolytic plaque forming cell (PFC) assay. SF mononuclear cells spontaneously secreted IgG, but little IgM or IgA. The SF cells failed to respond to the polyclonal B cell activators pokeweed mitogen (PWM) and Epstein-Barr virus. However, SF B cells cocultured with autologous T lymphocytes from the blood and stimulated with PWM secreted IgG but little IgM or IgA. The PFC responses of blood B cells cocultured with autologous SF T cells in the presence of PWM were low; irradiation of the T cells increased the blood B lymphocyte responses, but the differences were not statistically significant. It is concluded that suppressor SF T cells may be partly responsible for the poor response of SF B cells to PWM.

Synovial fluid and blood monocytes/macrophages in rheumatoid arthritis. Influence on polyclonal activation of autologous B lymphocytes

The regulatory role of synovial fluid monocytes/macrophages from patients with rheumatoid arthritis in terms of B lymphocyte activation was evaluated by a reverse haemolytic plaque-forming cell (PFC) assay. Macrophage-depleted blood mononuclear cells (BMC) failed to respond to pokeweed mitogen (PWM). With autologous synovial fluid macrophages added, the PFC responses of macrophage-depleted BMC increased, and optimal concentration for full restoration of the PFC responses ranged from 8 to 35%. Synovial fluid mononuclear cells (SMC) as well as macrophage-depleted SMC were not able to respond to PWM. Addition of irradiated autologous blood macrophages to SMC did not increase the SMC PFC responses. It is concluded that the regulatory properties of synovial fluid macrophages do not explain the low PFC response of SMC to PWM.

Effect of stimulated neutrophils from the synovial fluid of patients with rheumatoid arthritis on lymphocytes--a possible role of increased oxygen radicals generated by the neutrophils

Neutrophils from the synovial fluid (SFN) of 10 patients with active rheumatoid arthritis (RA) were investigated to determine the generation of oxygen intermediates (OI) (O2-, H2O2, OH .), chemiluminescence, and lysosomal enzymes (lysozyme and beta-glucuronidase). Lymphocytes from healthy individuals were cocultured at 37 degrees C for 17 hr with SFN from the patients and the number of OKT4+, OKT8+, and OKT3+ cells and the response to mitogens were determined. A markedly increased OI and slightly elevated lysosomal enzyme levels were observed in SFN from patients. Coculture of lymphocytes with SFN resulted in a decreased number of OKT4+ and OKT8+ cells and a greatly reduced response to Con A and mildly diminished response to PHA, while OKT3+ cells were not affected. The simultaneous addition of superoxide dismutase and catalase restored the impairment of monoclonal antibody reaction and lymphocyte responsiveness almost to control levels. It is suggested that the disturbed immunoreactivity of synovial fluid lymphocytes from RA patients may be due to increased OI generated by stimulated neutrophils.

Synovial fluid and blood monocyte influence on lymphocyte proliferation in rheumatoid arthritis and traumatic synovitis

The influence of synovial fluid and blood monocytes on autologous lymphocyte proliferation in vitro was investigated in patients with rheumatoid arthritis (RA) and traumatic synovitis (TS). In cultures stimulated with PHA, PWM and ConA, thymidine incorporation by RA blood mononuclear cells (BMC) increased considerably in most cases after addition of 10% or 30% synovial fluid monocytes and a similar effect was seen after stimulation with Candida extract or PPD. A comparable helper activity was observed after addition of synovial fluid monocytes to monocyte-depleted blood cells in RA. The augmenting effect of synovial fluid monocytes was likewise demonstrated in TS patients. Synovial fluid mononuclear cells (SMC) from RA and TS patients displayed low proliferative responses to PHA and ConA in comparison with BMC, while the responses to microbial antigens were similar or greater. The proliferative activity of SMC or of monocyte-depleted synovial fluid cells after polyclonal and antigenic stimulation was not affected by addition of blood monocytes. This was observed in both RA and TS patients. It is concluded that the regulatory properties of synovial fluid monocytes in RA and TS do not explain the low proliferative responses of SMC to polyclonal activators.

Functional characteristics of synovial fluid and blood mononuclear cells in rheumatoid arthritis and traumatic synovitis

The activity of blood mononuclear cells (BMC) and synovial fluid mononuclear cells (SMC) from patients with rheumatoid arthritis (RA) and traumatic synovitis (TS) was assessed by means of [14C]thymidine incorporation and production of leukocyte migration inhibitory factor (LIF). When compared with normal controls, spontaneous LIF production by BMC was found in 5 of 9 TS patients, whereas spontaneous LIF production by rheumatoid arthritis BMC and by SMC from both patient groups was infrequently seen. ConA-induced LIF production by BMC and SMC from both patient groups did not differ significantly from that of normal controls. Thymidine incorporation by unstimulated SMC and BMC was low in both patient groups. After stimulation with polyclonal activators, SMC showed significantly reduced proliferation in comparison with BMC, but the responses to microbial antigens were equal to or higher than those of BMC. The proliferative responses of stimulated SMC from TS patients were higher than the responses displayed by stimulated SMC from RA patients.

Studies on isolated gut mucosal lymphocytes in inflammatory bowel disease. Detection of activated T cells and enhanced proliferation to Staphylococcus aureus and lipopolysaccharides

To determine whether a defective proliferation of gut mucosal lymphocytes is a contributory factor to the pathogenesis of inflammatory bowel disease, we assessed their reactivity toward mitogens and bacterial antigens. Spontaneous replication of intestinal lymphoid cells was higher than that of patient-matched peripheral blood lymphocytes. That gut mucosal lymphocytes appear to be activated in loco was confirmed by a striking, time-dependent increase in the number of stable E rosettes generated by culturing unstimulated Crohn's disease intestinal lymphoid cells. The responses of lymphocytes from inflamed and normal mucosa to polyclonal mitogens were not only comparable to each other, but to those of corresponding peripheral lymphocytes, as well. Peripheral blood lymphocytes from patients with Crohn's disease showed less proliferation to Bacteroides and lipopolysaccharide antigens than did those from control individuals, but replicated similarly in response to Staphylococcus aureus and the enterobacterial common antigen: In contrast, when cultured with Staphylococcus aureus or with lipopolysaccharides, but mucosal lymphocytes from Crohn's disease proliferated 3-5 times more than did those from normal mucosa, while lymphoid cells from both sources were equally stimulated by Kunin antigen. Overall, this study found no evidence for a defective proliferative capacity of immune competent cells at the gut mucosal level in inflammatory bowel disease.

In vitro response to Corynebacterium parvum of human effusion lymphocytes isolated from patients with malignant and benign disease

Non-adherent effusion cells (EC), mostly lymphocytes, were isolated from the pleural effusions of 8 patients with malignant and 7 patients with benign disease. Corynebacterium parvum (Cp) induced increased methyl-3H-thymidine (methyl-3H-TdR) incorporation in EC cultures, but the response was lower than that usually found with autologous or allogeneic normal human blood lymphocytes. Experiments with highly purified effusion lymphocytes indicated that the response to CP was influenced by the presence of adherent cells, probably macrophages. Normal human monocytes incubated in vitro with supernatants of unstimulated EC cultures expressed slightly increased ability to suppress methyl-3H-TdR-incorporation in a human tumour cell line. Supernatants of Cp-stimulated EC induced a further increase in monocyte-mediated cytostatic activity. Cell-free effusion fluid from 8 patients were largely inactive when tested for induction of monocyte-mediated cytostatic activity in the same system, and the effusion fluid reduced monocyte methyl-3H-TdR-incorporation in vitro. Thus, Cp seems to be able to induce DNA-synthesis and release of mononuclear phagocyte-activating lymphokines in human effusion lymphocytes.

Effect of chemical modification and fragmentation on antigenic determinants of internal protein p30 and surface glycoprotein gp70 of type C retroviruses

The effects of protein modification on the antigenic determinants of p30 and gp70 of type C retroviruses were investigated by using solid-phase competition radioimmunoassays. Proteins were modified by reduction with 2-mercaptoethanol and subsequent carboxymethylation of SH groups with iodoacetamide or by amidination of alpha and epsilon amino groups with methylacetimidate. The type-specific determinants of gp70 were found to be conformational in nature, as they were destroyed by these chemical modifications. Group- and interspecies-specific determinants of gp70 antigens, however, appear to be sequential and do not involve residues susceptible to these chemical reagents. Conformation-dependent type-specific determinants of p30 were affected only by methylacetimidate. Group- and interspecies-specific determinants of p30 are similar to those of gp70 in that they also appear to be sequential antigenic sites. Therefore, the broadly reactive group- and interspecies-specific determinants of gp70 and p30 can be followed into small peptides. Accordingly, a cyanogen bromide cleavage fragment derived from the carboxyl-terminal one-third of Rauscher leukemia virus p30 was found to carry group-specific determinants but no detectable interspecies-specific determinants. In contrast, a peptide obtained by limited trypsin cleavage of p30, which was derived from the NH(2)-terminal region of the protein, contained at least one of the interspecies determinants shared with feline leukemia virus p27.

Membrane and transformation characteristics of lymphocytes isolated from the synovial membrane and paired peripheral blood of patients with rheumatoid arthritis

Membrane and transformation characteristics of lymphocytes isolated from the synovial membrane and from paired peripheral blood samples, obtained from patients with classical rheumatoid arthritis, were studied. Synovial tissue lymphocytes were isolated by a new technique. Two suspensions of peripheral blood lymphocytes were studied: one isolated by Ficoll-Isopaque density gradient centrifugation, the other enriched in T cells by an additional step of 1 hour nylon wool column filtration. All suspensions were characterised by the percentages of mononuclear phagocytic cells, and T and B lymphocytes. The spontaneous (3)H-thymidine uptake of synovial tissue lymphocyte suspensions always exceeded that of the peripheral blood lymphocyte suspensions. The in-vitro responsiveness of synovial tissue lymphocytes to PHA, Con-A, and PWM, as measured by (3)H-thymidine uptake, was always consistently lower than that of paired peripheral blood lymphocytes whether or not enriched in T cells. The responsiveness to antigens, including PPD, varidase, and an antigen cocktail consisting of varidase, trychophyton, and Staphylococcus aureus antigen, showed the same effect. No dissociation was found between the response to PPD and the other antigens studied. These results suggest that the relative unresponsiveness to mitogens and antigens of synovial tissue lymphocytes in comparison with blood lymphocytes is not caused by mononuclear phagocyte contamination, but either by different subsets of T lymphocytes or by different functional states of T lymphocytes present in the synovial membrane and peripheral blood of patients with rheumatoid arthritis.