Increase of CD57+ T cells in knee joints and adjacent bone marrow of rheumatoid arthritis (RA) patients: implication for an anti-inflammatory role

Lactobacillus rhamnosus reduces CD8+T cell mediated inflammation in patients with rheumatoid arthritis

BACKGROUND

The T cells, components of adaptive immunity participate in immune pathology of the autoimmune inflammatory disorder called rheumatoid arthritis (RA). The presence of TLRs on the surface of the CD8⁺ T cells and their ability to recognize bacterial moieties adds to the inflammatory burden in case of RA. It has been reported that the gut microbiome is necessary for the crucial shift in the balance between proinflammatory and anti-inflammatory cytokines. The altered gut microbiome and the presence of TLRs emphasizes on the microbiome driven inflammatory responses in case of RA.

METHODS

Eighty-nine RA patients participated in this study. Clinical variations like disease duration, number of actively inflamed joints, number and type of bone deformities, CRP, RF, Anti-CCP, ESR, DAS 28 score were recorded for each patient. Co-culture of CD8⁺T cells and bacteria has been performed with proper culture condition. TLRs and inflammatory mediators' expression level were checked by both qPCR and flow cytometry analysis.

RESULTS

We observed in the suppression of pro-inflammatory molecules like Granzyme B and IFNƳ and expression of TLR2 in CD8 + T cells upon treatment with Lactobacillus rhamnosus (L. rhamnosus). Moreover, L. rhamnosus activated CD8⁺T cells such that they could induce FOXP3 expression in CD4⁺T cells thereby skewing T cell population towards a regulatory phenotype. On the contrary, TLR4 engagement on CD8⁺T cell by Escherichia coli (E.coli) increased in inflammatory responses following ERK activation.

CONCLUSIONS

Thus, we conclude that L. rhamnosus can effectively suppress CD8⁺T cell mediated inflammation by a simultaneous decrease of Th1 cells that may potentiate better treatment modalities for RA.

Immune-mediated pore-forming pathways induce cellular hypercitrullination and generate citrullinated autoantigens in rheumatoid arthritis

Autoantibodies to citrullinated protein antigens are specific markers of rheumatoid arthritis (RA). Although protein citrullination can be activated by numerous stimuli in cells, it remains unclear which of these produce the prominent citrullinated autoantigens targeted in RA. In these studies, we show that RA synovial fluid cells have an unusual pattern of citrullination with marked citrullination of proteins across the broad range of molecular weights, which we term cellular hypercitrullination. Although histone citrullination is a common event during neutrophil activation and death induced by different pathways including apoptosis, NETosis, and necroptosis/autophagy, hypercitrullination is not induced by these stimuli. However, marked hypercitrullination is induced by two immune-mediated membranolytic pathways, mediated by perforin and the membrane attack complex (MAC), which are active in the RA joint and of importance in RA pathogenesis. We further demonstrate that perforin and MAC activity on neutrophils generate the profile of citrullinated autoantigens characteristic of RA. These data suggest that activation of peptidylarginine deiminases during complement and perforin activity may be at the core of citrullinated autoantigen production in RA. These pathways may be amenable to monitoring and therapeutic modulation.

Reactivity of autoantibodies against not only erythrocytes but also hepatocytes in sera of mice with malaria

In order to further examine the reactivity of autoantibodies, mice were infected with a non-lethal strain of Plasmodium yoelii. Parasitemia appeared between days 10 and 21. During this period, hyperglycemia and hypothermia were serially obeserved and this phenomenon resembled stress-associated responses. In parallel with parasitemia, autoantibodies appeared against nucleus and double-stranded DNA in the sera. To examine further the reactivity of autoantibodies against tissues, immunohistochemical staining using sera from mice with or without malaria was conducted. Autoantibodies contained reactivity to erythrocytes in the spleen, bone marrow and peripheral blood, especially against tissues obtained from mice with malaria. In the liver and intestine, autoantibodies reacted with hepatocytes and intestinal epithelial cells, respectively. These results suggested that the reactivity of autoantibodies against erythrocytes and hepatocytes might be associated with the modulation of the disease course in malaria.

CD57 expression and cytokine production by T cells in lesional and unaffected skin from patients with psoriasis

BACKGROUND

The immunopathogenic mechanisms leading to psoriasis remain unresolved. CD57 is a marker of replicative inability and immunosenescence on CD8+ T cells and the proportion of CD57 expressing CD8+ T cells is increased in a number of inflammatory conditions.

METHODOLOGY

We examined the expression of CD57 on T cells in the skin of patients affected with psoriasis, comparing lesional and unaffected skin. We also assessed functionality of the T cells by evaluating the secretion of several inflammatory cytokines (IL-17A, IFN-gamma, IL-2, IL-33, TNF-alpha, IL-21, IL-22, and IL-27), from cell-sorted purified CD4+ and CD8+ T cells isolated from lesional and unaffected skin biopsies of psoriasis patients.

PRINCIPAL FINDINGS

We observed that the frequency of CD57+CD4+ and CD57+CD8+ T cells was significantly higher in unaffected skin of psoriasis patients compared to lesional skin. Sorted CD4+ T cells from psoriatic lesional skin produced higher levels of IL-17A, IL-22, and IFN-gamma compared to unaffected skin, while sorted CD8+ T cells from lesional skin produced higher levels of IL-17, IL-22, IFN-gamma, TNF-alpha, and IL-2 compared to unaffected skin.

CONCLUSIONS/SIGNIFICANCE

These findings suggest that T cells in unaffected skin from psoriasis patients exhibit a phenotype compatible with replicative inability. As they have a lower replicative capacity, CD57+ T cells are less frequent in lesional tissue due to the high cellular turnover.

Fine phenotypic and functional characterization of effector cluster of differentiation 8 positive T cells in human patients with primary biliary cirrhosis

In primary biliary cirrhosis (PBC), patients develop a multilineage response to a highly restricted peptide of the E2 component of pyruvate dehydrogenase (PDC-E2) involving autoantibody and autoreactive cluster of differentiation (CD)4(+) and CD8(+) T-cell responses. Recent data from murine models have suggested that liver-infiltrating CD8(+) cells play a critical role in biliary destruction in PBC. We hypothesized that chronic antigen stimulation of CD8(+) T cells alters effector memory T cell (T(EM) ) frequency and function similar to that seen with chronic viral infections, including failure to terminally differentiate and relative resistance to apoptosis. We have rigorously phenotyped CD8(+) T-cell subpopulations from 132 subjects, including 76 patients with PBC and 56 controls, and report a higher frequency of T(EM) cells characterized as CD45RO(high) CD57(+) CD8(high), but expressing the gut homing integrin, α4β7, in peripheral blood mononuclear cells of PBC. These CD8(high) T(EM) cells have reduced expression of Annexin V after TCR stimulation. Consistent with a T(EM) phenotype, CD45RO(high) CD57(+) CD8(high) T cells express higher levels of granzyme A, granzyme B, perforin, CCR5 and α4β7, and lower levels of CCR7 and CD28 than other CD8(high) T cells. Furthermore, interleukin (IL)-5 produced by CD8(+) CD57(+) T lymphocytes upon in vitro T-cell receptor stimulation are increased in PBC. Histologically, CD8(+) CD57(+) T cells accumulate around the portal area in PBC. Moreover, CD8(+) CD57(+) T cells respond specifically to the major histocompatibility class I epitope of PDC-E2.

CONCLUSION

In conclusion, our data demonstrate that CD45RO(high) CD57(+) CD8(high) T cells are a subset of terminally differentiated cytotoxic T(EM) cells, which could play a critical role in the progressive destruction of biliary epithelial cells.

PSK may suppress CD57(+) T cells to improve survival of advanced gastric cancer patients

BACKGROUND

A recent report showed that oral adjuvant immunochemotherapy with protein-bound polysaccharide K (PSK) and tegafur/uracil (UFT) for stage II and III colorectal cancer improves overall survival compared with UFT alone. PSK has been supposed to improve survival through immunological mechanisms such as induction of cytokines, regulation of Th1/Th2 balance, and inhibition of immunosuppressive molecules.

METHODS

We investigated the mechanisms by which PSK influences immunological parameters such as Th1 cells (IFN-gamma-positive CD4(+) T cells), Th2 cells (IL-4-positive CD4(+) T cells), Th1/Th2 ratio, NKT cells (CD56(+) T cells and CD57(+) T cells), NK cells, and CD25(+)CD4(+) T cells in stage III gastric cancer patients. Patients were randomly assigned to receive either 3 g PSK plus 300 mg UFT (PSK group) or 300 mg UFT alone (control) orally each day for at least 1 year following their operation.

RESULTS

Twenty-one registered patients with stage III gastric cancer were analyzed. The 3-year overall survival was 62.2% in the PSK group (n = 10) and 12.5% in the control group (n = 11) (P = 0.038). Before operation, there were no significant differences in the proportions of Th1 cells, Th2 cells, Th1/Th2 ratio, CD56(+) T cells, CD57(+) T cells, NK cells, and CD4(+)CD25(+) T cells between PSK and control groups. However, after operation, CD57(+) T cells decreased significantly in the PSK group compared to the control (P = 0.0486). When all patients were analyzed, patients with increased proportion (>18%) of CD57(+) T cells showed worse survival than those with lower (< or = 18%) CD57(+) T cells (3-year survival, 25.0 and 45.7%, respectively; P = 0.046), consistent with our previous report that high CD57(+) is an indicator of poor prognosis in patients with advanced gastric cancer. However, in the group treated with PSK + UFT, 3-year survival of CD57-high patients was as great as that of CD57-low patients (66.7 and 51.4%, respectively; P = 0.67).

CONCLUSION

The present findings suggest that PSK improves overall survival of stage III gastric cancer patients partly by inhibiting CD57(+) T cells, a proven poor prognostic factor in advanced gastric cancer.

Effects of simvastatin on circulating autoantibodies to oxidized LDL antigens: relation with immune stimulation markers

Statins exert a number of anti-inflammatory and immunomodulatory effects in vitro. However, the immunomodulatory effects in vivo are less clarified. In the present study, we investigated whether simvastatin treatment changed the levels of autoantibodies against specific oxidized LDL (oxLDL) antigens as well as their association with leukocyte activation markers. Eighty volunteers with mild-to-moderate hypercholesterolemia were randomized to either simvastatin 40 mg or placebo for 6 weeks. Autoantibodies against apo B peptide antigens, C-reactive protein (CRP) and interleukin (IL)-6 in plasma were determined by ELISA. Subsets of circulating B and T cells were studied by flow cytometry. Simvastatin significantly reduced CRP by 26%, whereas IL-6 remained unchanged. Levels of IgG against the apo B peptide P-240 (amino acids 3586-3605) increased by 16% (p = 0.03) in the simvastatin group whereas autoantibody levels to other apo B peptides did not change. At baseline and after 6 weeks, the P-240 IgG levels were significantly correlated with the number of CD57+CD28 - CD8+T cells but not to other lymphocyte subsets or inflammatory markers. The P-240 IgG levels after 6 weeks simvastatin therapy was strongly correlated to the relative increase in CD57+CD28 - CD8+T cells (p = 0.003). Simvastatin treatment induced an increase in autoantibodies against an oxLDL antigen. The effect was related to an expansion of a CD8+T cell subset and may involve an immunostimulation by simvastatin.

Prognostic value of CD57(+) T lymphocytes in the peripheral blood of patients with advanced gastric cancer

BACKGROUND

Natural killer (NK)-like T cells comprising CD56(+) T cells and CD57(+) T cells belong to a subset of CD1d-independent NKT cells playing an important role in regulating immune responses. Although NK-like T cells are reported to increase in patients with advanced gastric carcinomas, it remains unknown how NK-like T cells are involved in disease progression in gastric cancer patients.

METHODS

The proportions of Th1 cells (interferon [IFN]-gamma-producing CD4(+) T cells), Th2 cells (IL-4-producing CD4(+) T cells), and NK-like T cells (CD56(+) T cells and CD57(+) T cells) in the peripheral blood of 48 gastric cancer patients and 20 healthy controls were measured by two-color flow cytometry analysis and by intracellular cytokine analysis to investigate an association of these immune cells with the survival rate of gastric cancer patients.

RESULTS

Univariate analysis showed that Th1 cells and CD57(+) T cells, as well as some clinicopathological factors, significantly influenced the survival rate. CD57-high (> or ==18%) patients survived for a significantly shorter period after surgery compared to CD57-low patients (P = 0.046; Kaplan-Meier, log-rank test) in the stage III-IV patients, but not in the stage I-II patients. Further, multivariate analysis showed that lymphatic invasion was a statistically significant independent risk factor in all the gastric cancer patients, but the proportion of CD57(+) T cells as well as depth of tumor were statistically significant independent risk factors in patients with advanced carcinomas (stage III-IV).

CONCLUSION

An increased proportion (> or ==18%) of CD57(+) T cells in the peripheral blood of patients with advanced gastric carcinomas could indicate a poor prognosis.

Impact of cytomegalovirus and grafts versus host disease on the dynamics of CD57+CD28-CD8+ T cells after bone marrow transplant

OBJECTIVES

The present study aimed to evaluate the dynamics of CD28 and CD57 expression in CD8+ T lymphocytes during cytomegalovirus viremia in bone marrow transplant recipients.

METHODS

In a prospective study, blood samples were obtained once weekly once from 33 healthy volunteers and weekly from 33 patients. To evaluate the expression of CD57 and CD28 on CD8+ T lymphocytes, flow cytometry analysis was performed on blood samples for four months after bone marrow transplant, together with cytomegalovirus antigenemia assays.

RESULTS

Compared to cytomegalovirus-seronegative healthy subjects, seropositive healthy subjects demonstrated a higher percentage of CD57+ and a lower percentage of CD28+ cells (p<0.05). A linear regression model demonstrated a continuous decrease in CD28+ expression and a continuous increase in CD57+ expression after bone marrow transplant. The occurrence of cytomegalovirus antigenemia was associated with a steep drop in the percentage of CD28+ cells (5.94%, p<0.01) and an increase in CD57+ lymphocytes (5.60%, p<0.01). This cytomegalovirus-dependent effect was for the most part concentrated in the allogeneic bone marrow transplant patients. The development of acute graft versus host disease, which occurred at an earlier time than antigenemia (day 26 vs. day 56 post- bone marrow transplant), also had an impact on the CD57+ subset, triggering an increase of 4.9% in CD57+ lymphocytes (p<0.05).

CONCLUSION

We found continuous relative changes in the CD28+ and CD57+ subsets during the first 120 days post- bone marrow transplant, as part of immune system reconstitution and maturation. A clear correlation was observed between the expansion of the CD57+CD28-CD8+ T lymphocyte subpopulation and the occurrence of graft versus host disease and cytomegalovirus viremia.

Immunologic states of autoimmune diseases

The etiology and immunologic states of autoimmune diseases have mainly been discussed without consideration of extrathymic T cells, which exist in the liver, intestine, and excretion glands. Because extrathymic T cells are autoreactive and are often simultaneously activated along with autoantibody-producing B-1 cells, these extrathymic T cells and B-1 cells should be introduced when considering the immunologic states of autoimmune diseases. The immunologic states of autoimmune diseases resemble those of aging, chronic GVH disease, and malarial infection. Namely, under all these conditions, conventional T and B cells are rather suppressed concomitant with thymic atrophy or involution. In contrast, extrathymic T cells and B-1 cells are inversely activated at this time. These facts suggest that the immunologic states of autoimmune diseases should be reevaluated by introducing the concept of extrathymic T cells and autoantibody-producing B-1 cells, which might be primordial lymphocytes in phylogeny.

Interleukin-15 selectively expands CD57+CD28−CD4+ T cells, which are increased in active rheumatoid arthritis

Proinflammatory cytokines as well as CD4(+) T cells play critical roles in the pathogenesis of rheumatoid arthritis (RA). Recently, an increase of CD57(+) or CD28(-)CD4(+) T cells was demonstrated in RA, although the mechanism of the increase of these T cells is unclear. In this study, we first examined the relationship between CD57(+)CD4(+) T cells and CD28(-)CD4(+) T cells and found CD57(+)CD28(-)CD4(+) T cells, but neither CD57(+)CD28(+) nor CD57(-)CD28(+) cells, expanded in the peripheral blood of active RA. In vitro experiments revealed that CD57(+)CD28(-)CD4(+) T cells selectively expanded in response to IL-15. Furthermore IL-15-stimulated CD57(+)CD28(-)CD4(+) T cells induced TNF-alpha production from monocytes. These results suggest that CD57(+)CD28(-)CD4(+) T cells are involved in the pathogenesis of RA by responding to IL-15.

The role of the T cell in autoimmune inflammation

T cells, in particular CD4⁺ T cells, have been implicated in mediating many aspects of autoimmune inflammation. However, current evidence suggests that the role played by CD4⁺ T cells in the development of rheumatoid inflammation exceeds that of activated proinflammatory T-helper (Th)1 effector cells that drive the chronic autoimmune response. Subsets of CD4⁺ T cells with regulatory capacity, such as CD25⁺ regulatory T (Treg) cells and Th2 cells, have been identified, and recent observations suggest that in rheumatoid arthritis the function of these regulatory T cells is severely impaired. Thus, in rheumatoid arthritis, defective regulatory mechanisms might allow the breakdown of peripheral tolerance, after which the detrimental Th1-driven immune response evolves and proceeds to chronic inflammation. Here, we review the functional abnormalities and the contribution of different T cell subsets to rheumatoid inflammation.

Analysis of the susceptibility of CD57 T cells to CD3-mediated apoptosis

After stimulation with anti-CD3 antibody in vitro, CD57(+) T cells showed a greater susceptibility to apoptosis than CD57(-)alphabetaT cell receptor (TCR)(+) T cells (regular alphabeta T cells). The apoptotic fraction of CD57(+) T cells showed an increased production of active caspase-3. An increase in both Fas expression and Fas-ligand (FasL) production was also observed in CD57(+) T cells, whereas the expression of survivin was suppressed in CD57(+) T cells compared to that of regular alphabeta T cells. CD57(+) T cells display a biased expansion of a few Vbeta T cell fractions in individuals, but such Vbeta T cells were not specifically susceptible to CD3-mediated apoptosis. The TCR expression level of CD57(+) T cells was much lower than that of regular T cells and anti-TCR antibody stimulation induced a smaller apoptotic proportion of CD57(+) T cells than did anti-CD3 antibody. Although the CD3epsilon expression levels were similar in both T cell subsets, the CD3zeta level of CD57(+) T cells was significantly higher than that of regular T cells. These results suggest that several apoptotic and anti-apoptotic molecules are involved in the CD3-induced apoptosis of CD57(+) T cells and raise the possibility that the imbalance in expression of the CD3epsilon and CD3zeta chains may also contribute to the susceptibility of CD57(+) T cells to undergo apoptosis.

No mixing of granulocytes and other lymphocytes in the inflamed joints of parabiosis mice with collagen-induced arthritis: possible in situ generation

Collagen-induced arthritis was evoked by an injection of lipopolysaccharide and anti-type II collagen antibody in mice. In parallel with the onset of arthritis, granulocytes with large light scatter and a Mac-1(+) Gr-1(+) phenotype expanded in the joints of these mice. Lymphocytes with a CD3(-) B220(+) phenotype (i.e. B220(+) B cells) were the major population among lymphocyte subsets in the joints, irrespective of disease. To determine the origin of these leucocyte populations in the joints and other organs, parabiotic experiments using CBF(1)Ly5.1 and CBF(1)Ly5.2 mice were conducted in mice with and without collagen-induced arthritis. As expected, leucocyte populations in the liver and spleen became a half-and-half mixture of their own cells and partner cells (e.g. approximately 45% of Ly5.1(+) cells in Ly5.2(+) partner mice). However, such a mixture was extremely delayed in the joints and bone marrow, even in mice with arthritis. These results suggest that, because circulatory blood is not exchanged in the joints, granulocytes and other lymphocytes are generated in situ in the inflamed joints of mice with collagen-induced arthritis or are possibly supplied by the bone marrow. It is of interest that granulocytes in the joints expanded, even without a supply from another site, namely, the synovium.

Chemokine receptors in the rheumatoid synovium: upregulation of CXCR5

In patients with rheumatoid arthritis (RA), chemokine and chemokine receptor interactions play a central role in the recruitment of leukocytes into inflamed joints. This study was undertaken to characterize the expression of chemokine receptors in the synovial tissue of RA and non-RA patients. RA synovia (n = 8) were obtained from knee joint replacement operations and control non-RA synovia (n = 9) were obtained from arthroscopic knee biopsies sampled from patients with recent meniscal or articular cartilage damage or degeneration. The mRNA expression of chemokine receptors and their ligands was determined using gene microarrays and PCR. The protein expression of these genes was demonstrated by single-label and double-label immunohistochemistry. Microarray analysis showed the mRNA for CXCR5 to be more abundant in RA than non-RA synovial tissue, and of the chemokine receptors studied CXCR5 showed the greatest upregulation. PCR experiments confirmed the differential expression of CXCR5. By immunohistochemistry we were able to detect CXCR5 in all RA and non-RA samples. In the RA samples the presence of CXCR5 was observed on B cells and T cells in the infiltrates but also on macrophages and endothelial cells. In the non-RA samples the presence of CXCR5 was limited to macrophages and endothelial cells. CXCR5 expression in synovial fluid macrophages and peripheral blood monocytes from RA patients was confirmed by PCR. The present study shows that CXCR5 is upregulated in RA synovial tissue and is expressed in a variety of cell types. This receptor may be involved in the recruitment and positioning of B cells, T cells and monocytes/macrophages in the RA synovium. More importantly, the increased level of CXCR5, a homeostatic chemokine receptor, in the RA synovium suggests that non-inflammatory receptor–ligand pairs might play an important role in the pathogenesis of RA.

Functional and Vbeta repertoire characterization of human CD8+ T-cell subsets with natural killer cell markers, CD56+ CD57- T cells, CD56+ CD57+ T cells and CD56- CD57+ T cells

We investigated the individual CD8+ populations with natural killer (NK) cell markers (NK-type T cell); CD56 single positive (CD56)-T cells, CD56/CD57 double positive (DP)-T cells and CD57 single positive (CD57)-T cells in the peripheral blood. All NK-type T-cell populations expressed CD122 and intermediate levels of T-cell receptor (TCR; regular CD8+ T cells are CD122- and express high levels of TCR). The number of both DP-T cells and CD57-T cells, but not CD56-T cells, gradually increased with age. All NK-type T-cell populations produced larger amounts of interferon-gamma than did regular CD8+ T cells after stimulation with interleukin (IL)-2, IL-12 and IL-15. However, CD56-T cells and CD57-T cells but not DP-T cells showed a potent antitumour cytotoxity to NK-sensitive K562 cells, whereas only CD56-T cells showed a potent cytotoxity to NK-resistant Raji cells. Furthermore, although NK-type T cells produced large amounts of soluble Fas-ligands, their cytotoxic activities appeared to be mediated by the perforin/granzyme pathway. The oligoclonal or pauciclonal expansions of certain VbetaT cells were found in each NK-type T-cell population. The non-variant CDR3 region(s) for the TCRbeta chain(s) showed CD57-T cells and CD56-T cells to be derived from distinct origins, while the DP-T cell population consisted of a mixture of the clones seen in both CD56-T cells and CD57-T cells. Our results suggest that CD57-T cells and CD56-T cells are functionally and ontogenically different populations while DP-T cells appear to originate from both CD56-T cells and CD57-T cells.

Immunomodulation by the autonomic nervous system: therapeutic approach for cancer, collagen diseases, and inflammatory bowel diseases

The distribution of leukocytes is regulated by the autonomic nervous system in humans and animals. The number and function of granulocytes are stimulated by sympathetic nerves whereas those of lymphocytes are stimulated by parasympathetic nerves. This is because granulocytes bear adrenergic receptors, but lymphocytes bear cholinergic receptors on the surface. These regulations may be beneficial to protect the body of living beings. However, when the autonomic nervous system deviates too much to one direction, we fall victim to certain diseases. For example, severe physical or mental stress --> sympathetic nerve activation --> granulocytosis --> tissue damage, including collagen diseases, inflammatory bowel diseases, and cancer. If we introduce the concept of immunomodulation by the autonomic nervous system, a new approach for collagen diseases, inflammatory bowel diseases, and even cancer is raised. With this approach, we believe that these diseases are no longer incurable.

Involvement of CD4+,CD57+ T cells in the disease activity of rheumatoid arthritis

OBJECTIVE

To evaluate the relationship between the frequency of peripheral CD57+ T cells and the physical status of rheumatoid arthritis (RA) patients, and to perform cytokine analysis of these CD57+ T cells.

METHODS

Four-color fluorescence-activated cell sorter analysis was performed to detect both cell surface antigens and intracellular cytokines in peripheral blood leukocytes, using monoclonal antibodies against CD3, CD4, CD8, CD57, interferon-gamma (IFNgamma), and interleukin-4 (IL-4). RA patients were clinically evaluated with a modified Health Assessment Questionnaire (M-HAQ), joint score, face scale, and visual analog scale (VAS) assessing pain and disease activity.

RESULTS

There was a significant correlation between the frequency of CD4+,CD57+ T cells and erythrocyte sedimentation rate (ESR), whereas a correlation was not found between the frequency of CD8+,CD57+ T cells and ESR. The frequency of CD4+,CD57+ T cells also showed a significant correlation with the mHAQ score, VAS, and face scale. Again, there was no significant correlation between the above-mentioned clinical scores and the frequency of CD8+,CD57+ T cells. Flow cytometric analysis of intracellular cytokines revealed that 14.5% of the CD57+ T cells produced IFNgamma, whereas only 2.8% of the CD57+ T cells produced IL-4 in RA patients.

CONCLUSION

Evidence showing that the frequency of CD4+,CD57+ T cells among CD3+ cells of RA patients had a significant correlation not only with ESR but also with the physical status of the patients, and that a large proportion of the CD4+,CD57+ T cells had the capacity to produce IFNgamma, strongly suggests that these CD4+,CD57+ T cells are involved in the immunopathogenesis of RA.

CD8+CD28- T cells: certainties and uncertainties of a prevalent human T-cell subset

Human peripheral blood CD8+ T cells comprise cells that are in different states of differentiation and under the control of complex homeostatic processes. In a number of situations ranging from chronic inflammatory conditions and infectious diseases to ageing, immunodeficiency, iron overload and heavy alcohol intake, major phenotypic changes, usually associated with an increase in CD8+ T cells lacking CD28 expression, take place. CD8+CD28- T cells are characterized by a low proliferative capacity to conventional stimulation in vitro and by morphological and functional features of activated/memory T cells. Although the nature of the signals that give origin to this T-cell subset is uncertain, growing evidence argues for the existence of an interplay between epithelial cells, molecules with the MHC-class I fold and CD8+ T cells. The possibility that the generation of CD8+CD28- T cells is the combination of TCR/CD3zeta- and regulatory factor-mediated signals as a result of the sensing of modifications of the internal environment is discussed.

Systematic characterization of human CD8+ T cells with natural killer cell markers in comparison with natural killer cells and normal CD8+ T cells

We investigated the function of CD56+ CD8+ T cells (CD56+ T cells) and CD56- CD57+ CD8+ T cells (CD57+ T cells; natural killer (NK)-type T cells) and compared them with those of normal CD56- CD57- CD8+ T cells (CD8+ T cells) and CD56+ NK cells from healthy volunteers. After the stimulation with immobilized anti-CD3 antibodies, both NK-type T cells produced much larger amounts of interferon-gamma (IFN-gamma) than CD8+ T cells. Both NK-type T cells also acquired a more potent cytotoxicity against NK-sensitive K562 cells than CD8+ T cells while only CD56+ T cells showed a potent cytotoxicity against NK-resistant Raji cells. After the stimulation with a combination of interleukin (IL)-2, IL-12 and IL-15, the IFN-gamma amounts produced were NK cells > or = CD56+ T cells > or = CD57+ T cells > CD8+ T cells. The cytotoxicities against K562 cells were NK cells > CD56+ T cells > or = CD57+ T cells > CD8+ T cells while cytotoxicities against Raji cells were CD56+ T cells > CD57+ T cells > or = CD8+ T cells > or = NK cells. However, the CD3-stimulated proliferation of both NK-type T cells was smaller than that of CD8+ T cells partly because NK-type T cells were susceptible to apoptosis. In addition to NK cells, NK-type T cells but not CD8+ T cells stimulated with cytokines, expressed cytoplasmic perforin and granzyme B. Furthermore, CD3-stimulated IFN-gamma production from peripheral blood mononuclear cells (PBMC) correlated with the proportions of CD57+ T cells in PBMC from donors. Our findings suggest that NK-type T cells play an important role in the T helper 1 responses and the immunological changes associated with ageing.

Decreased CD57 lymphocyte subset in patients with chronic Lyme disease

BACKGROUND

Chronic Lyme disease (LD) is a debilitating illness caused by tickborne infection with the spirochete Borrelia burgdorferi. Although immunologic abnormalities appear to play a role in this disease, specific immunologic markers of chronic LD have not been identified.

METHODS

We evaluated 73 patients with chronic LD for lymphocyte subset abnormalities using flow cytometry. Of these, 53 patients had predominant musculoskeletal symptoms, while 20 patients had predominant neurologic symptoms. The estimated duration of infection ranged from 3 months to 15 years, and all patients had positive serologic tests for B. burgdorferi. Ten patients with acute LD (infection less than 1 month) and 22 patients with acquired immunodeficiency syndrome (AIDS) served as disease controls.

RESULTS

All 31 chronic LD patients who were tested prior to antibiotic treatment had significantly decreased CD57 lymphocyte counts (mean, 30+/-16 cells per microl; normal, 60-360 cells per microl, P<0.001). Nineteen of 37 patients (51%) who were tested after initiating antibiotic therapy had decreased CD57 levels (mean, 66+/-39 cells per microl), and all five patients tested after completing antibiotic treatment had normal CD57 counts (mean, 173+/-98 cells per microl). In contrast, all 10 patients with acute LD and 82% of AIDS patients had normal CD57 levels, and the difference between these groups and the pre-treatment patients with chronic LD was significant (P<0.001). Patients with chronic LD and predominant neurologic symptoms had significantly lower mean CD57 levels than patients with predominant musculoskeletal symptoms (30+/-21 vs. 58+/-37 cells per microl, P=0.002). CD57 levels increased in chronic LD patients whose symptoms improved, while patients with refractory disease had persistently low CD57 counts.

CONCLUSIONS

A decrease in the CD57 lymphocyte subset may be an important marker of chronic LD. Changes in the CD57 subset may be useful to monitor the response to therapy in this disease.

The differential effect of stress on natural killer T (NKT) and NK cell function

When C57Bl/6 mice were exposed to restraint stress for 12 h or 24 h, lymphocytopenia was induced in the liver, spleen, and thymus. We examined which types of lymphocytes were sensitive or resistant to such stress by a immunofluorescence test. T cells of thymic origin were sensitive while NKT and NK cells were resistant. In contrast to the increase in the proportion of NK cells, NK activity of liver lymphocytes against YAC-1 targets decreased at 24 h after stress. On the other hand, their NKT cytotoxicity against syngeneic thymocytes increased in parallel with an increase in their proportion. In perforin -/- B6 mice and B6-gld/gld (Fas ligand-) mice, NK cells were found to mediate cytotoxicity through perforin while NKT cells mediated self-reactive cytotoxicity through Fas ligand. These results suggest that stress increases the proportion of both NK and NKT cells, but that NK cytotoxicity is suppressed while self-reactive NKT cytotoxicity is not, due to a diversity of their functional mechanisms.

Establishment and usefulness of an anti-human CD57 IgG1 monoclonal antibody

In the present study we established a new monoclonal antibody, JNK-1, which recognizes all cells recognized by CD57/HNK-1 mAb. JNK-1 and CD57 mAbs inhibited the binding of each other, suggesting that the molecules they recognize are either identical or sufficiently close to cause steric hindrance in the binding assay. JNK-1 mAb detected the 110-kDa protein, which is identical to the protein recognized by CD57/HNK-1 mAb in Western immunoblot analysis combined with immunoprecipitation. Therefore, JNK-1 mAb appears to recognize homogeneous molecules identified by the currently available CD57 mAb. Notably, JNK-1 mAb is composed of mouse IgG1 heavy chains, and thus can be used easily in immunoprecipitation, which cannot easily be performed with the available CD57 mAb because it is an IgM isotype. Thus, JNK-1, which is an IgG isotype, may present a useful tool to elucidate the CD57 protein.

CD57+ cells in radicular cyst

AIM

As CD57 antigen is an important modulator of the immune system, the purpose of the present study was to compare the expression of this antigen on radicular cysts (RC) with hyperplastic or atrophic epithelium.

METHODOLOGY

Twenty cases of RC were retrieved and classified as atrophic or hyperplastic. A biotin-streptavidin amplified system was used for identification of the CD57 receptor.

RESULTS

The results demonstrated a greater percentage of CD57+ cells in RC with atrophic epithelium compared to hyperplastic epithelium.

CONCLUSION

As the expression of CD57 is indicative of immunosuppression, it may constitute a negative immunomodulator of RC's epithelium growth. Further studies are necessary to understand the importance of this cell to the biological activity or inactivity of RC's epithelium development.

Comparative immunophenotypic study of lichen sclerosus: epidermotropic CD57+ lymphocytes are numerous--implications for pathogenesis

To characterize the immunophenotype of inflammatory cells in lichen sclerosus (LS), we performed a comparative case control study using one- and two-color immunohistochemistry and the nitro blue tetrazolium (NBT) reaction. Study material consisted of 100 biopsies from patients with LS or from 12 control groups consisting of inflammatory, scarring, and depigmenting cutaneous disorders. In addition, fresh tissue was sampled from four vulvectomy specimens for NBT testing. The typical inflammatory infiltrate of LS contained numerous epidermotropic CD3+, CD8+, CD57+ cells, increased intraepidermal HLA-DR+ cells, and a dermal infiltrate rich in CD8+, CD57+, HLA-DR+, and CD68+ inflammatory cells. Comparing LS to the 12 control groups, epidermotropic CD57+ lymphocytes independently predicted LS (P = 0.006, logistic regression, multivariate analysis). Among the 12 control groups, only specimens of the inflammatory stage of morphea exhibited numerous dermal CD57+ lymphocytes. Two-color immunohistochemistry confirmed the CD3+/CD8+CD57+ and CD3+/ CD8+/CD57+HLA-DR+ epidermotropic and dermal lymphocytic phenotypes and the dermal macrophage CD68+HLA-DR+ phenotype. In LS, the NBT reaction revealed evidence of superoxide production associated with CD68+HLA-DR+ cells. Expansion of CD8+CD57+lymphocytes is associated with viral infections, autoimmune disease, malignancies, and transplantation and is suspected to be the result of chronic excessive antigen challenge. In these pathologic states, CD8+CD57+ lymphocytes (as terminally differentiated, antigen-specific T cells) participate in the suppression of cytolytic activity to limit tissue damage. In LS, activated macrophages and lymphocytes indicate persistent antigen-driven inflammation. LS's numerous CD8+CD57+ lymphocytes may be either the mediators or the consequence of its hallmark sclerosis.

CD56+ T cells in the peripheral blood of uveitis patients

AIMS

Natural killer T (NKT) cells, T lymphocytes expressing both T cell and NK cell markers, are suggested to be involved in autoimmune diseases. To examine the relation between the pathogenesis of uveitis and CD56+ T cells, which are thought to be a type of human NKT cells, we investigated peripheral CD56+ T cells in uveitis patients.

METHODS

41 uveitis patients (Behçet's disease (BD), 14; sarcoidosis (SAR), eight; Vogt-Koyanagi-Harada disease (VKH), five; idiopathic uveitis (IU), nine; and others, five) and 19 healthy controls participated in this study. Cell surface antigens of lymphocytes were analysed by use of monoclonal antibodies and flow cytometry.

RESULTS

The proportion of CD56+ T cells in patients with BD was higher than in controls and in patients with SAR, VKH, IU, and others.

CONCLUSION

Increased peripheral CD56+ T cells might be relevant to the pathogenesis of uveitis in BD, and increase of peripheral CD56+ T cells may be one of the laboratory findings to suggest that uveitis originates from BD.

Expansion of Extrathymic T Cells as Well as Granulocytes in the Liver and Other Organs of Granulocyte-Colony Stimulating Factor Transgenic Mice: Why They Lost the Ability of Hybrid Resistance

When we attempted to characterize the immunological state in G-CSF transgenic mice, a large number of not only granulocytes but also lymphoid cells expanded in various immune organs. Such lymphoid cells were present at unusual sites of these organs, e.g., the parenchymal space in the liver. We then determined the phenotype of these lymphoid cells by immunofluorescence tests. It was demonstrated that CD3intIL-2Rβ+ cells (i.e., extrathymic T cells), including the NK1.1+ subset of CD3int cells (i.e., NKT cells), increased in the liver and all other tested organs. These T cells as well as NK cells mediated NK and NK-like cytotoxicity, especially at youth. However, they were not able to mediate such cytotoxicity in the presence of granulocytes. This result might be associated with deficiency in the hybrid resistance previously ascribed to these mice. In other words, G-CSF transgenic mice had a large number of extrathymic T cells (including NKT cells) and NK cells that mediate hybrid resistance, but their function was suppressed by activated granulocytes. Indeed, these granulocytes showed an elevated level of Ca2+ influx upon stimulation. The present results suggest that, in parallel with overactivation of granulocytes, extrathymic T cells and NK cells are concomitantly activated in number but that their function is suppressed in G-CSF transgenic mice.

NK phenotypic markers and IL2 response in NK cells from elderly people

Immunosenescence is a process that primarily affects the T cell compartment of the immune system, although age-associated immunological alterations have also been demonstrated in the NK cell phenotype and function. A significant expansion in the number of NK cells is found in aging. The NK cytotoxic capacity of total peripheral blood lymphocytes is also well preserved, not only in healthy elderly people but also in centenarians. However, NK cell killing of K562 is impaired when considered in a per-cell basis, and this defect is associated with defective signal transduction after activation more than a diminished conjugate formation or killing capacity. We have studied the phenotype of NK cells in elderly donors fulfilling the Senieur criteria. We have also studied the capacity of these cells to be activated by IL2 when different NK cell functions, other than cytotoxicity, are considered. Our results confirm the increased percentage of NK cells in the elderly due to the expansion of the CD56dim subset that also show an altered pattern of activation markers, whereas no differences were found in the CD56bright subset. The response of NK cells to IL2 was found to be impaired when proliferation, expression of CD69, and Ca2+ mobilization were considered, whereas TNF-alpha production was not significantly affected. These results suggest that human NK cells do not escape the aging process, although senescence have a differential effect on distinct NK cell biological functions, ranging from severe to negligible impairment, depending on the parameters considered.