Soluble IL-2 receptor and CD25 cells in psoriasis: effects of cyclosporin A and PUVA therapy.

A study was conducted to quantify soluble IL-2 receptor (sIL-2R) levels in sera of 57 chronic plaque psoriasis patients and correlate these measurements with disease activity and the number of IL-2R-positive (CD25+) lymphocytes in lesional biopsies of 11 cyclosporin A (CsA) and 13 psoralen plus ultraviolet radiation (PUVA) treated patients. Levels of sIL-2R showed a strong correlation with the psoriasis area and severity index (PASI). CsA and PUVA significantly reduced the PASI and sIL-2R levels to a similar degree after 4 weeks of treatment. Although the majority of CsA-treated patients who were biopsied showed reductions in lesional CD25+ cells, these did not reach statistical significance; in five patients biopsied who had PUVA treatment, no consistent effect on the numbers of CD25+ cells was observed. A significant correlation was found between CD25+ cells in lesional biopsies and the PASI score.     

Haemolytic-uraemic syndrome in recipients of bone marrow transplants not treated with cyclosporin A

We report three cases of haemolytic-uraemic syndrome following bone marrow transplantation in young males. None of them was treated with cyclosporin A. All died in renal failure. Renal histology showed the typical appearances of haemolytic-uraemic syndrome. Immunoperoxidase examination of renal biopsies showed IgM and complement in blood vessels and glomeruli of all three cases. Cytomegalovirus infection was present in two cases and probable in the third. Two cases had been infected with herpes zoster. All had episodes of graft-versus-host disease. Possible pathogenetic mechanisms are discussed.     

Reconstitution of the intermediate-affinity interleukin-2 receptor by cell fusion.

Although IL-2 receptor beta chain (IL-2R beta) expressed in various lymphoid cell lines binds IL-2 with an intermediate affinity, IL-2R beta expressed in fibroblasts is unable to bind IL-2, suggesting that IL-2R beta is on its own not sufficient for generating the intermediate-affinity receptor and that lymphoid-specific regulatory control may be operated to allow IL-2R beta to bind IL-2. In the present study, we observed that human IL-2R beta expressed in a mouse myeloma X63-Ag8.653 (X63) by cDNA transfection did not bind IL-2, while the same IL-2R beta expressed in an IL-6-dependent mouse B cell hybridoma F12-28, which was obtained by cell fusion between X63 and lipopolysaccharide (LPS)-induced lymphoblasts, bound IL-2 with the intermediate affinity. Interestingly, when the human IL-2R beta cDNA-transfected X63 clone, which by itself manifests no IL-2 binding, was fused with LPS-induced lymphoblasts, the resultant hybridomas manifested intermediate-affinity IL-2 binding. The IL-2 binding was specifically inhibited by addition of antihuman IL-2R beta mAb (Mik-beta 1) but not by mAb against mouse IL-2R subunits, indicating that human IL-2R beta was responsible for the IL-2 binding, i.e. non-functional human IL-2R beta in X63 was converted to competent IL-2R beta by complementation with a mouse spleen cell-derived factor(s) through the cell fusion. Cross-linking experiments with [125I]IL-2 revealed the presence of a 61 kDa protein other than IL-2R beta in cells expressing the intermediate-affinity IL-2R.(ABSTRACT TRUNCATED AT 250 WORDS)     

IgA肾病患者IL—2的产生及IL—2受体的表达

本文对IgA肾病(IgAN)外周血淋巴细胞白细胞介素2(IL-2)的产生、受体的表达及免疫球蛋白的产生进行了研究。结果发现:外周血淋巴细胞产生IL-2的活性明显增高,IL-2受体表达亦明显增强并伴有免疫球蛋白产生增多,提示IgAN存在着细胞免疫功能的紊乱。     

IL-2 receptor gene expression and IL-2 production by human preterm newborns' cells.

IL-2 receptor (IL-2R) gene expression in human umbilical cord blood mononuclear cells (CBMC) of preterm and term newborns was examined following stimulation for 18 h with phytohaemagglutinin (PHA) and compared with that of adult peripheral blood mononuclear cells (PBMC; mothers and control group). mRNA for IL-2R could not be detected in CBMC of preterm infants, whereas the mRNA levels for IL-2R found in full term neonates were similar to those observed in PBMC of adults. IL-2 activity in conditioned medium (CM) of mononuclear cells stimulated with either optimal or suboptimal PHA concentrations for 24 h and 48 h was also determined. At 24 h of stimulation, IL-2 activity found in CM obtained from CBMC of preterm and term newborns was significantly higher than that found in CM of adults' PBMC. A further enhancement of IL-2 activity (six to eight times) was observed in CM of preterm and term cells stimulated for 48 h, whereas no significant difference was found in IL-2 activity in CM from adult cells tested at the two incubation periods. The present findings may provide an additional explanation for the impaired function of the immune system, and the high susceptibility to infections observed in preterm newborns.     

强直性脊柱炎及类风湿关节炎患者IL—2及IL—2受体测定

应用流式细胞仪检测强直性脊柱炎(AS)及类风湿关节炎(RA)患者外周血淋巴细胞(PBL)表面IL-2受体(IL-2R)及经PHA刺激、体外培养产生的IL-2。结果表明,AS患者PBL表达IL-2R无明显增加,而RA患者则明显高于正常人及AS患者(P<0.01);AS及RA患者PBL体外培养产生IL-2明显多于正常人(P<0.01),提示IL-2异常在AS及RA患者免疫功能失调中起重要作用。     

Regulation of IL-2 beta receptor expression and beta-chain mRNA by human thymocytes.

The high affinity form of the human IL-2 receptor (IL-2R) has two known components, the IL-2R alpha (p55) and the IL-2R beta chain (p75). We have previously shown that recombinant IL-2 (rIL-2) could induce the expression of the alpha-chain (p55) on T cells and thymocytes, and increase this expression following suboptimal activation with concanavalin A (Con A) in combination with IL-2. An increase in the accumulation of IL-2R alpha-specific mRNA induced by rIL-2 in T cells and thymocytes had also been documented. We report here that the expression of IL-2R beta on the cell surface can be demonstrated on human thymocytes by the binding of Mik beta1, a MoAb directed against an epitope of the beta-chain. The IL-2R beta chain is constitutively expressed on freshly isolated thymocytes; this expression can be increased in thymocytes activated with Con A in combination with IL-2 or tetradecanoylphorbol 13-acetate (TPA). Blocking the formation of high affinity receptors with a MoAb directed against the alpha-chain of the receptor results in an increase in the display of IL-2R beta as evidenced by binding of MoAb Mik beta1. The accumulation of IL-2R-beta-specific mRNA is observed in freshly isolated thymocytes and it is increased in thymocytes cultured with rIL-2 alone, with Con A, and further enhanced by the addition of rIL-2 in combination with Con A or with TPA. Cyclosporine (CsA), which inhibits the accumulation of lymphokine-specific mRNA of thymocytes, does not inhibit the induction of the accumulation of IL-2R beta-specific mRNA. This is analogous to its effect on the expression of the alpha-chain (p55), and the accumulation of alpha-chain-specific mRNA.     

High-grade T-cell lymphoma following treatment with cyclosporin A

A 47-year-old man with persistent severe oropharyngeal ulceration developed a high-grade T-cell lymphoma soon after commencing treatment with cyclosporin A. Using Southern blotting to identify T-cell beta-chain gene rearrangements, evidence of clonal restriction was found both in blood and lymph node DNA samples. Two BamH1 rearranged bands were demonstrated in both samples. In the blood a 16 Kb band predominated, with a weaker 28 kb band. In the lymph node sample this pattern was reversed. The findings suggest that a bi-clonal population of T-lymphocytes or clonal evolution of an existing T-cell monoclone had developed, and that cyclosporin contributed to the emergence of a high-grade T-cell lymphoma.     

Follow up of soluble IL-2 receptor level in metastatic malignant melanoma patients treated by chemoimmunotherapy.

Immunological parameters following chemoimmunotherapy combination were studied in 31 patients with metastatic malignant melanoma. They received Cisplatin (100 mg/m2) on day 1 and 28, recombinant IL-2 (rIL-2; Eurocetus) in continuous infusion from day 3 to 6, 17 to 21, 31 to 34 and 45 to 49. Interferon-alpha (IFN-alpha; Roche) was given subcutaneously three times weekly. No significant change in CD4/CD8 ratio at onset or during treatment was observed between responder (n = 19) and non-responder (n = 12) patients. Regarding the IL-2 receptor (IL-2R) study, the percentage of cells expressing Tac (p55) receptor did not change either for healthy volunteers (n = 20) and patients before any therapy, or between responder and non-responder patients. Concerning serum soluble IL-2R shedding before therapy, we observed a significant increase (P = 0.001) in patients (79 +/- 40 pM) compared with healthy donors (30 +/- 15 pM), but no significant variation was seen between responder and non-responder patients. In contrast, during the treatment, the soluble IL-2R level increased in both groups but, interestingly, a significant difference was found between responder and non-responder patients from day 7 (P < 0.05) to day 21 (P < or = 0.01), suggesting that the cells from non-responder may be slower in becoming stimulated. This finding is the most striking point of our study and suggests that sIL-2R might be an early predictive factor of the clinical response as obtained by logistic regression (P = 0.0063). Therefore patients with a serum soluble IL-2R level greater than 250 pM at day 21 have a 12-fold more chance of undergoing a clinical response.     

Interleukin-2 receptor concentrations in pregnant women with a history of recurrent miscarriage.

BACKGROUND: The mechanism by which the maternal immune system tolerates the fetus during pregnancy is unclear. METHODS: This study measured interleukin-2 receptor (IL-2R) concentrations in the serum of non-pregnant women (Group 1); healthy first trimester pregnant women (Group 2); pregnant women with a history of recurrent miscarriage whose pregnancies again failed later in the first trimester (Group 3); and first trimester pregnant women with a history of recurrent miscarriage but whose pregnancies on this occasion went successfully to term (Group 4). An initial sample was obtained from all women in Groups 1, 2, 3 and 4. A further sample was obtained 4 weeks later from women in Groups 1, 2 and 4. RESULTS: The initial sample showed no significant difference in IL-2R concentrations between Groups 1 and 2. Concentrations were significantly higher in Groups 3 (667 +/- 244 U/ml; P < 0.003) and 4 (730 +/- 360 U/ml; P < 0.05) compared with healthy pregnant women (425 +/- 94). When the second sample was obtained concentrations in Group 4 were found to have fallen so that they no longer differed from Group 2. CONCLUSIONS: Our results confirm earlier findings that a successful pregnancy is associated with significantly lower concentrations of IL-2R.     

Relationship between IL-2 receptor expression and proliferative responses in lymphocytes from HIV-1 seropositive homosexual men.

Previous studies have shown that exogenous IL-2 does not correct the reduction in phytohaemagglutinin (PHA)-induced proliferation of lymphocytes from HIV-1 infected (HIV+) individuals. We investigated the mechanism of this reduction to determine if reduced expression of the complete IL-2 receptor (IL-2R) was responsible. In a series of experiments, PHA-stimulated lymphocytes from a total of 89 HIV- and 93 HIV+ homosexual men from the Baltimore Multicentre AIDS Cohort Study (MACS) were studied to determine the expression of messages for the alpha and beta subunits of the IL-2R, the binding of 125I-IL-2 to high affinity IL-2R, and the effect of IL-2 on cell proliferation. Compared to HIV- donors, PHA-stimulated lymphocytes from most HIV+ donors demonstrated (i) a reduction in high affinity IL-2R expression that correlated with the reduction in the IL-2-induced proliferative response; and (ii) a reduction in expression of both IL-2R alpha- and beta-chain mRNA which may be responsible for decreased high affinity IL-2R expression. However, lymphocytes from some HIV+ individuals had borderline low IL-2-induced proliferation despite normal or elevated expression of high affinity IL-2R. These results suggest that decreased expression of IL-2R may account, at least in part, for the lower proliferative response of cells from HIV+ donors.     

Inhibition of the human allogeneic mixed lymphocyte response by cyclosporin A: relationship with the IL-12 pathway

Interleukin-12 (IL-12) is an important cytokine in the control of cell-mediated immunity. We have previously shown that endogenous IL-12 plays a role in the development of human allogeneic response. In the present study, we investigated the relationship between Cyclosporin A (CsA)-inhibitory effect and IL-12 pathway during human alloreaction in vitro. CsA addition at the sensitizing phase of primary mixed lymphocyte reaction (MLR) resulted in the inhibition of both p40 and p70 IL-12 production in a dose-dependent manner. In contrast, CsA had no effect on IL-12-receptor β1 chain (IL-12 Rβ) expression in T cells induced upon allogeneic activation. Addition of exogenous IL-12 significantly restored CsA-inhibited alloreactive cytotoxic T lymphocyte (CTL) generation and had a marginal effect on T cell proliferative response. The IL-12-induced restoration of CTL generation was IFNγ-mediated, as it was significantly altered when anti-IFNywas added. The restoration of CTL activity by exogenous IL-12 correlated with the capacity of this cytokine to partially restore granzyme B mRNA expression in alloreactive CTL. This study indicates that inhibition of IL-12 production is a novel additional mechanism for the inhibitory effect of CsA on the development of human allogeneic cytotoxic response.     

Interleukin-2 receptor expression in benign and malignant melanocytic skin lesions

The immunophenotype of the lymphocytic reaction of melanocytic skin lesions (12 cases of cutaneous malignant melanoma (CMM), three of Hutchinson's melanotic freckle (HMF), and eight naevocellular naevi) has been studied using monoclonal antibodies. CMM was associated with the most intense lymphocytic reaction, the lymphocytes being T cells of both CD-4 T helper/inducer and CD-8 suppressor/cytotoxic subsets which were present in varying proportions. Although less marked, the lymphocytic reaction to HMF and benign naevi showed similar features. An antibody to the interleukin-2 receptor (IL-2R; Tac, CD-25) was included in the panel and the earlier findings of positively stained cells in association with CMM were confirmed. In addition, the novel finding of these cells in association with HMF and naevocellular naevi is reported. The number of these CD-25 positive cells was extremely variable but they appeared most prominent in association with CMM. The findings presented here indicate that it is not possible to infer that CD-25 positive lymphocytes present in the host response to CMM necessarily indicates tumour specific activation of the cells of the host immune system.     

Study of IL-2 receptor expression after chemoimmunotherapy in patients treated for metastatic malignant melanoma.

Using flow cytometry, cellular IL-2 receptors were studied before and following chemoimmunotherapy combination in 20 patients with metastatic malignant melanoma (MMM). Patients received cisplatin (100 mg/m2) at days 1 and 28, recombinant IL-2 by continuous infusion from days 3 to 6, 17 to 21, 31 to 34, and 45 to 49. Interferon-alpha (IFN-alpha) was given subcutaneously three times weekly. In terms of clinical response, we observed 55% objective response (complete: 15%). When pretreatment blood samples were compared with those of healthy donors, we did not observe any change in low (alpha chain) and high affinity receptor (alpha + beta) expression. In contrast, intermediate affinity p75 (beta chain) expression was decreased significantly (P < or = 0.0001) in MMM patients. During treatment, we found a dramatic increase of beta chain as well as high affinity (alpha + beta) expression in responding patients, as soon as IL-2 therapy began. Furthermore, the increase of beta chain expression was limited to natural killer (NK) cells (CD56+). In non-responding patients, on the other hand, increase of both receptors was seen only at day 31. These data suggest the involvement of beta chain expression in the mechanism of cell activation after chemoimmunotherapy. Moreover, this early beta chain expression is correlated with the clinical response to chemoimmunotherapy.     

Defective de novo thymocyte maturation in cyclosporin A (CsA)-induced autoimmunity: expression of costimulatory and activation molecules

Lethally x-irradiated Lewis rats, reconstituted with syngeneic bone marrow and transiently treated with CsA for 4 weeks, will develop an autoimmune disease about 2–3 weeks after cessation of CsA therapy. CsA-induced autoimmunity is a thymus-dependent and T cell-mediated autoimmune disease. CsA is thought to generate autoreactive T cells by interference with negative selection in the thymus; x-irradiation is required to eliminate the peripheral autoregulatory T cell circuit. In this study we re-evaluate the effect of CsA on thymic atrophy and thymocyte maturation. Subsequently we examine the expression of costimulatory and activation molecules (CD2, CD5, CD11a, CD11b, CD25, CD28, CD43, CD54, OX-40, RT-1A, RT-1B and RT-1D) during distinct maturational stages in order to detect possible clues to the observed effects of CsA on thymocyte maturation and selection. The results revealed that CsA blocks maturation of double-positive TCR^int to double-positive TCR^high thymocytes and preferentially inhibits the development of mature CD4 single-positive thymocytes. Furthermore, CsA administration resulted in a reduced expression of the costimulatory CD2 molecule. Although it is a matter of debate whether this defective CD2 expression is involved in the aberrant maturation and selection of thymocytes, it is speculated that reduced costimulation via CD2 may influence differentiation into distinct T cell subsets.     

IL-2 regulation of soluble IL-2 receptor levels following thermal injury.

In the immunosuppressed burn patient serum levels of both IL-2 and a soluble form of IL-2 receptor alpha (sIL-2R alpha) are significantly elevated. Strikingly, the production of these markers by the in vitro activated patients' cells is decreased. This study examines the role of IL-2 in the decreased production of the sIL-2R alpha in vitro in patients with major burns (n = 18, 30 to greater than 70% total body surface area). Peripheral blood mononuclear cell (PBMC) cultures from patients with highly elevated serum sIL-2R alpha, and from healthy controls (n = 12) were activated with concanavalin A (Con A) at initiation. In patients' cultures mitogen-induced increments of sIL-2R alpha levels were significantly lower. There was a significant negative correlation (r = 0.64, P less than 0.001) between a high serum sIL-2R alpha level and a decreased lectin-induced sIL-2R alpha release in vitro. Low levels of sIL-2R alpha in patients' samples were not normalized by increasing the number of T lymphocytes. Also exogenous rIL-1 was without effect, whereas rIL-3 increased sIL-2R alpha release in some cultures. However, sIL-2R alpha levels were significantly increased in patients' cultures by (i) addition of exogenous IL-2; (ii) removal of adherent cells; (iii) addition of cyclooxygenase inhibitor, indomethacin; (iv) bypassing cell surface activation by the combination of the calcium ionophore A23187 and the phorbol ester 12-o-tetradecanoyl acetate. The cyclic AMP-elevating drug, forskolin, abrogated the ability of exogenous IL-2 to increase sIL-2R alpha production. Thus, in the burn patient, the reduced in vitro sIL-2R alpha release appears to relate to abnormalities in IL-2 production and action mediated through its functional surface receptor. Elevated levels of sIL-2R alpha in vivo may, therefore, reflect systemic activation of T lymphocytes in response to biologically active IL-2.     

The effect of FK506 and cyclosporin A on antigen-induced arthritis.

FK506 and cyclosporin A inhibited the development of antigen-induced arthritis in the rat and rabbit. FK506 was five times more potent than cyclosporin A in the rat and approximately 20 times more potent in the rabbit. FK506 was effective in both species if administered either from the day of intra-articular administration of antigen or when the arthritis was established. In the rabbit, arthritis returned when administration of FK506 was stopped. FK506 (10 mg/kg/day) caused renal damage which was not observed at a dose of 2.5 mg/kg/day. Both of these doses were equally effective at inhibiting the arthritis. The conclusion from these studies is that FK506 is a more effective anti-arthritic agent than cyclosporin A and that a pronounced therapeutic effect can be achieved at non-toxic doses of the drug.     

Tumour-infiltrating lymphocytes in primary melanoma: functional consequences of differential IL-2 receptor expression

Tumour-infiltrating lymphocytes (TIL) have been isolated from early primary melanoma (Clark level III) and expanded in vitro using culture conditions with low concentrations of IL-2 (50 U/ml). Immediately after isolation TIL consisted of mainly CD3⁺ T cells, and the portion of CD56⁺ natural killer (NK) cells was below 20%. Fresh TIL cultures could be distinguished by CD25 expression since some contained up to 33%, others less than 5% CD25⁺ cells. These showed differences in subsequent development during in vitro expansion. CD25-cxprcssing cultures remained stable in their phenotype, whereas the second TIL type showed major changes: CD3 (ca 70–30%) expression decrease. CD25 (ca 5–35%) and CD56(ca 15–55%) expression increase. The TIL type, which remained dominated by CD3⁺ T cells, killed autologous tumour cells efficiently (⁵¹Cr-rclcase greater than 30% at a E/T ratio of 20:1). which could be blocked by MoAbs against MHC class I molecules. In contrast, the other TIL type exhibited weak cytotoxicity (less than 17%⁵¹Cr-release at an E/T ratio of 20:1) against the autologous tumour. Therefore, the expression of CD25 on freshly isolated TIL is a good marker for tumour specificity of in vitro expanded TIL.     

Soluble IL-2 receptor levels in patients with Graves'' ophthalmopathy.

In various autoimmune diseases circulating levels of soluble IL-2 receptor (sIL-2R) seem to be related to disease activity. Because reliable parameters of disease activity in Graves' ophthalmopathy are lacking, we measured sIL-2R levels in 47 patients with this disorder. The patients had Graves' disease, but no other immune-mediated diseases, had not yet received specific treatment for their ophthalmopathy and were euthyroid during the entire study period. Twenty-one of the 47 patients (45%) had sIL-2R values above the upper normal limit of 650 U/ml, as established in 20 healthy controls. There were no differences between patients with normal (median 469, range 280-644 U/ml) and elevated (median 946, range 678-1588 U/ml) sIL-2R levels regarding duration or severity of the eye disease (as assessed clinically from the total eye score). However, patients with severely enlarged eye muscles had higher sIL-2R values than patients with less severely enlarged eye muscles on CT scan. Patients with elevated sIL-2R tended to have a higher response rate (71%) to a 3-month course of prednisone, than those with normal levels (46%; P = 0.081). Since a successful outcome of prednisone treatment might be representative for disease activity, the elevated sIL-2R levels seem to reflect active inflammation. Although the practical relevance of this finding in individual patients is limited, it underscores the importance of cell-mediated immune responses in this thyroid-related eye disease.