The effect of serum from patients with acute myocardial infarction on in vitro lymphocyte reactivity. I. Inhibition of mitogen stimulation.

Sera from 20 patients obtained within 24 hours and one week after acute myocardial infarction (AMI) were tested for their immunomodulating effect on concanavalin-A (con-A) stimulated lymphocyte cultures from 11 healthy unrelated donors. Individual control sera from 21 healthy donors and 5 pools of control sera were used for comparison. Cortisol levels were tested in patients' and controls' sera. A significantly higher suppressive effect was seen in the presence of patients' sera taken at 24 hours than corresponding sera taken one week later. However, the suppressive effect after one week was increased as compared to control sera. A significant correlation between the degree of suppression and the cortisol level in corresponding sera was observed. An increased immunosuppression was observed with increased cortisol levels.     

p24 antibody production in p24 antibody-negative HIV-infected subjects.

To determine if HIV-infected patients with no detectable serum antibodies to p24 are producing antibodies to p24 (anti-p24), blood was obtained from 49 HIV-infected patients at various stages of infection. Serum p24 antigen levels were measured and peripheral blood mononuclear cells were cultured for 1 week without mitogenic stimulation. The presence of anti-p24 in culture supernatants and sera was determined by radioimmunoprecipitation assays. Cells from 89% of the patients who had anti-p24 in their sera spontaneously synthesized anti-p24 in vitro. Similarly, cells from 83% of the HIV-infected patients who had no detectable anti-p24 in their sera spontaneously produced anti-p24 in vitro. Thus the absence of anti-p24 in serum did not reflect suppression in the ability of patients' cells to synthesize and secrete antibodies to p24. However, cells from patients whose sera contained anti-p24 spontaneously synthesized more anti-p24 than did cells from patients whose sera lacked anti-p24, suggesting that these two groups of patients may represent individuals with inherently high or low responses to p24 epitopes, respectively.     

急性心肌梗死后辅助性T细胞功能失衡的意义

目的：探讨急性心肌梗死(AMI)后辅助性T淋巴(Th)细胞功能失衡的意义。方法： 采用流式细胞分析法对33例AMI病人，22例不稳定心绞痛(UA)病人和35例AMI大鼠进行Th细胞胞内干扰素γ(IFN-γ)和白介素4(IL-4)的动态监测，同时应用RT-PCR方法检测AMI大鼠心肌组织IFN-γ和IL-4以及T细胞表面趋化因子受体CCR3、CCR5和CXCR3 mRNA的表达。结果：AMI和UA病人发病24 h内Th1型胞内IFN-γ的水平明显高于对照组。UA患者IFN-γ高表达持续时间较短，发病1周后恢复；AMI患者IFN-γ高表达持续时间较长，发病后1周甚至1月仍增高。Th2型胞内IL-4未见明显变化。AMI大鼠心梗后Th细胞胞内IFN-γ和IL-4均无明显变化，T细胞表面趋化因子受体CCR3、CCR5和CXCR3 mRNA表达亦无显著差异，但AMI 1周、2和1月末心肌组织局部IFN-γ mRAN的表达明显增加。结论： AMI后机体出现T细胞功能失衡，主要表现为Th1细胞功能亢进，可能参与AMI的发病；AMI后T细胞功能失衡可能作为自身免疫病的发病机制之一，参与了AMI后自身免疫性心肌炎的发病和自身免疫因素引起的心肌损伤和心室重塑过程。     

Interleukin 2 synthesis in the presence of steroids: a model of steroid resistance.

In this study interleukin 2 (IL-2) synthesis by human lymphocytes in the presence and absence of prednisolone in a group of normal subjects has been assessed. An association between suppression in vitro of induced phytohaemagglutinin-blastogenesis by prednisolone and synthesis of IL-2 was found. Those subjects whose lymphocytes are identified as steroid-resistant have significantly higher IL-2 activity in the supernatants of both steroid and non-steroid treated lymphocyte cultures than steroid sensitive subjects. The addition of exogenous IL-2 was found to ablate the suppressive effects of steroids on lymphocyte blastogenesis. These results suggest that significantly greater activity of IL-2 in the culture supernatants of steroid resistant subjects may represent a mechanism for glucocorticoid resistance in vitro and help explain the relationship between increased loss of grafts and steroid resistance in renal allograft recipients.     

Stimulation of heart contractility by supernatants from lectin-activated lymphocytes. Role of IL-2

The positive inotropic effect of cell-free supernatants from lectin-activated lymphocytes is lost by dialysis and can be partially restored by addition of arachidonic acid (AA). Interleukin-2 (IL-2) in the presence of AA could stimulate the response of the heart while the interferons (alpha-IFN or gamma-IFN) were ineffective. The activity of PHA-L-SN and that of IL-2 + AA was neutralized by anti-IL-2 MAb. These results suggest a key role for IL-2 in the stimulation of heart contractility by supernatants from activated lymphocytes.     

Serum immunomodulatory factors in gastrointestinal diseases. A 30-50-kD serum fraction in Crohn''s disease capable of modulating lymphocyte activation.

We tested the hypothesis that serum factors present in Crohn's disease interfere with the process of lymphocyte activation. The mitogen-induced proliferation and the expression of early activation antigens by normal lymphocytes cultured in the presence of either Crohn's disease sera or sera from different controls were evaluated. The mitogen-induced proliferation was significantly impaired in the presence of Crohn's disease sera. These sera markedly inhibited the mitogen-induced interleukin-2 receptor (IL-2R) expression (48% inhibition), while the effect of sera on the expression of the transferrin receptor and the 4F2 antigen was much less pronounced. Diafiltration experiments showed that the inhibitory effect was confined to a 30-50-kD serum fraction. Such a serum property was not related to the patients' disease activity and disappeared after surgical removal of the affected bowel. The capability of inhibiting the mitogen-induced IL-2R expression was not restricted to Crohn's disease and was observed with sera from other inflammatory and neoplastic gastrointestinal disorders. This study indicates that a marked inhibition of the IL-2R is a mechanism underlying the immunosuppressive property of the serum in Crohn's disease and in other gastrointestinal conditions.     

Inhibitory Activity of Soluble IL-2R in Sera, Ascites and Culture Supernatants from Murine Leukaemic Cells

The effect of sera from mice bearing a T cell lymphoid leukaemia (LB) and the supernatants from short term cultures of the tumour cells were studied on cell proliferation using syngeneic and allogeneic normal and tumour cells. An inhibitory activity was demonstrated in 24–48 h supernatants of LB cells in culture and disappeared after 4 days of culture. Inhibitory activity was cytostatic but not cytotoxic and was non-specific since it inhibited the growth of both syngeneic and allogeneic normal and tumour cells. Such activity was found in the 10⁵–1.3 × 10⁵ Mr serum fraction after a Sephacryl S200 chromatography. Though sensitive to protease, trypsine or neuraminidase treatment, which indicated its glycoprotein nature, it remained stable after heating or freezing-thawing cycles as well as after alkaline, acid or hyaluronidase treatment. Addition of exogenous IL-2 abrogated inhibitory activity. ELISA showed the presence of soluble IL-2R both in LB conditioned medium and in above serum fraction.
It is demonstrated that the inhibitory factor, soluble IL-2R, is produced by LB leukaemia cells, then secreted into blood and ascitic fluid or released into culture supernatants. Soluble IL-2R exerts inhibitory activity blocking cell proliferation and modulating immune response by binding to free IL-2.     

A soluble form of the human transferrin receptor is released by activated lymphocytes in vitro.

Soluble transferrin receptors (sTfR) were detected in culture supernatants of activated human peripheral blood mononuclear cells (PBMC) using a sandwich ELISA technique with two non-cross-reacting TfR MoAbs. Mitogenic stimulation of lymphoid cells induced both up-regulation of TfR surface density and release of sTfR to the medium. Peak levels of sTfR in culture supernatants occurred at day 4 after activation, 1 day later than maximum expression of TfR in the plasma membrane. Production of sTfR was independent of proliferation, as demonstrated by measuring sTfR release by PBMC, which had been irradiated with a dose of 20 Gy before activation. In addition to these in vitro experiments, we tested the sera of 85 patients with systemic lupus erythematosus (SLE), an autoimmune disease accompanied by in vivo activation of lymphocytes, for their sTfR levels. No correlation of these data was detectable to serum concentrations of the soluble alpha-chain of the IL-2 receptor, an unequivocal marker of lymphocyte activation. However, they correlated negatively to the haemoglobin content of the patients' erythrocytes, indicating that erythroid progenitors are the predominant source of sTfR in SLE patients' sera.     

Defective autologous mixed leukocyte reaction in newly diagnosed type 1 diabetes mellitus.

We studied autologous mixed leukocyte reaction (AMLR) in type 1 (insulin-dependent) diabetes mellitus (IDDM) patients, their healthy siblings and healthy schoolchildren, Blood samples from the patients were drawn within 1 week after hospitalization and 2 months later. AMLR was significantly depressed in the patients when compared to healthy siblings or other healthy controls. In addition, the mean AMLR responsiveness of the healthy control group exceeded that of healthy siblings. The production of IL-2 in AMLR was impaired in the patient group and the defective AMLR could be restored by addition of exogenous IL-2 in 7-10 patient cultures. However, in 3-10 patients addition of IL-2 induced no enhancement of proliferation. While the patients in general had raised levels of activated T lymphocytes these three patients had higher numbers of activated T cells than other patients. Defective AMLR and presence of activated T cells may be related and may play a role in the pathogenesis of IDDM.     

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.     

Modulation of IL-1 alpha, IL-1 beta, and 25K Mr non-IL-1 activity released by human mononuclear cells

To determine if the release of IL-1 alpha and IL-1 beta by cultured PBMC could be independently modulated by different exogenous stimuli, we examined the effect of LPS, IFN gamma, latex beads, and indomethacin on the release of IL-1 alpha and IL-1 beta. PBMC culture supernatants were fractionated by Sephacryl-S-200 column chromatography or HPLC (TSK G3000SW), and each fraction was tested for thymocyte mitogenic activity in the presence or absence of preincubation with anti-IL-1 alpha or anti IL-1 beta monoclonal antibody (mAb) and for the presence of IL-1 alpha or IL-1 beta protein by ELISA. In all experiments, thymocyte mitogenic activity not neutralizable by anti-IL-1 alpha or anti-IL-1 beta mAb was detected in the 25K Mr range, which ranged from 12 to 50% of the total thymocyte mitogenic activity released, depending on the stimuli. Cultured PBMC from 95% of individuals release thymocyte mitogenic activity in the absence of exogenous stimuli, which was increased 1.3-to 7-fold by lopopolysaccharide (LPS) (25-50 micrograms/ml). All of this increased activity was due to increased release of IL-1 beta and non-IL-1 thymocyte mitogenic activity, with no change in the total amount of IL-1 alpha released. Indomethacin (0.1 microgram/ml) induced release of increased thymocyte mitogenic activity of 1.3- to 1.4-fold over unstimulated cultures. All of this increased activity was due to increased release of IL-1 alpha and non-IL-1 activity with a concomitant decrease in IL-1 beta release. Interferon gamma (40-100 U/ml) increased the amount of IL-1 alpha and decreased IL-1 beta and non-IL-1 activity released, resulting in no overall change in the total amount of thymocyte mitogenic activity. Molecular weight fractionation of the PBMC culture supernatants revealed that thymocyte mitogenic activity eluting in the 25K Mr range was not due to IL-1 alpha or IL-1 beta. With certain culture conditions, thymocyte mitogenic activity was detected in the 30-40K Mr range. PBMC cultured with LPS and latex beads in the absence of serum released 30-40K Mr IL-1 alpha, as well as 17K Mr IL-1 alpha and 17K Mr IL-1 beta. PBMC cultured in 2% fetal calf serum (FCS) alone from some donors released only 30-40K Mr thymocyte mitogenic activity. Both IL-1 alpha and IL-1 beta protein was detected by ELISA in this Mr range but only the IL-1 alpha was bioactive.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interleukin-2 Induced Mitogenesis of Human Peripheral Blood T-Lymphocytes: Role of Accessory Cells

We and others have shown that Interleukin-2 (IL-2) is mitogenic to a subset of unstimulated T lymphocytes in human peripheral blood (1-7). We extend our work here in showing that prolonged continuous exposure of human peripheral blood lymphocytes to exogenous IL-2 throughout the 7-8 day culture is not necessary since mitogenesis occurs reproducibly after short term (2-3 hr) pulse exposure. The mitogenic effect of pulse exposure to IL-2 is not significantly reduced by inclusion of anti-Tac monoclonal antibody in the pulsing medium. However, anti-Tac monoclonal antibody markedly inhibits the response if present continuously throughout the 7 day culture.

The mitogenic effect of IL-2 is dependent on the presence of accessory cells (monocytes) but the accessory cell requirement can be replaced by the phorbol ester TPA (10^-8 to 10^-11 M). Purified monocytes subjected to short term pulse exposure to IL-2 can cause proliferative response in unprimed autologous lymphocytes in cocultures. The mitogenic effect of IL-2 pulsed monocytes can not be suppressed by inclusion of anti-Tac antibody in the pulsing medium although the same concentration of the antibody suppresses the effect if present throughout culture. The response of lymphocytes to IL-2 pulsed monocytes is not inhabitable by the continuous presence of a monoclonal antibody to human HLA-DR antigens (OK-Ial) in culture.     

Allergen-specific induction of interleukin-2 (IL-2) responsiveness in lymphocytes from children with asthma. II. Regulation of IL-2 responsiveness by supernatants of normal lymphocytes

Induction of interleukin-2 (IL-2) responsiveness by Dermatophagoides farinae (Df)-stimulated lymphocytes from children with asthma was markedly suppressed after the addition of culture supernatants from Df-stimulated normal T cells. Ovalbumin (OVA)-induced IL-2 responsiveness of lymphocytes from patients with hen-egg allergy was not suppressed by the supernatant from Df-stimulated T cells, indicating the antigenic specificity of the effect. Patients' lymphocytes whose IL-2 responsiveness was decreased still expressed Tac antigen (low-affinity IL-2 receptors) but, in contrast to the patients' original lymphocytes, did not absorb or respond to IL-2, suggesting the loss of high-affinity IL-2 receptors (p55/p75) from these cells. The supernatant from Df-stimulated normal T cells from one individual did not necessarily suppress the response of all patients tested, indicating the existence of some allogeneic barrier between the factor(s) and patients' lymphocytes.     

Interleukin-2 Induced Mitogenesis of Human Peripheral Blood T-Lymphocytes: Role of Accessory Cells

We and others have shown that Interleukin-2 (IL-2) is mitogenic to a subset of unstimulated T lymphocytes in human peripheral blood (1–7). We extend our work here in showing that prolonged continuous exposure of human peripheral blood lymphocytes to exogenous IL-2 throughout the 7–8 day culture is not necessary since mitogenesis occurs reproducibly after short term (2–3 hr) pulse exposure. The mitogenic effect of pulse exposure to IL-2 is not significantly reduced by inclusion of anti-Tac monoclonal antibody in the pulsing medium. However, anti-Tac monoclonal antibody markedly inhibits the response if present continuously throughout the 7 day culture.

The mitogenic effect of IL-2 is dependent on the presence of accessory cells (monocytes) but the accessory cell requirement can be replaced by the phorbol ester TPA (10^?8 to 10^?11 M). Purified monocytes subjected to short term pulse exposure to IL-2 can cause proliferative response in unprimed autologous lymphocytes in cocultures. The mitogenic effect of IL-2 pulsed monocytes can not be suppressed by inclusion of anti-Tac antibody in the pulsing medium although the same concentration of the antibody suppresses the effect if present throughout culture. The response of lymphocytes to IL-2 pulsed monocytes is not inhabitable by the continuous presence of a monoclonal antibody to human HLA-DR antigens (OK-Ial) in culture.     

Effect of Pseudomonas aeruginosa exotoxin a on PHA-induced lymphocyte proliferation

P. aeruginosa Exotoxin A induced a dose dependent suppression of PHA-stimulated human lymphocyte proliferation. The suppressor effect was not reversed by interleukin 2 (IL-2) added to the culture medium. Expression of IL-2 receptors (IL-2R) on PHA-blasts a well as their ability for IL-2 binding were decreased by Exotoxin A. Kinetic studies of IL-2 production showed that IL-2 activity was still present in cultures of lymphocytes activated for 72 hours with PHA and Exotoxin A. In contrast, supernatants of lymphocyte cultures activated with PHA and Exotoxin A for 18 hours had low activity of IL-2. Hence, Exotoxin A probably could decrease the utilization of IL-2 due to either inhibition of IL-2R expression or suppression of their ability for IL-2 binding.     

Dissociation between interleukin-1 and interleukin-2 production in proliferative response to microbial antigens: restorative effect of exogenous interleukin-2.

The relationship between the production of interleukin-1 (IL-1) and interleukin-2 (IL-2) after stimulation of human mononuclear cells within an antigenic extract from Candida albicans was analyzed in both responder and nonresponder donors. Culture supernatants from responders contained both IL-1 and IL-2 activity, whereas the supernatants from nonresponders contained only IL-1 and no appreciable IL-2. However, the addition of exogenous IL-2 to nonresponder cultures restored the normal proliferative response. Similar observations were made when cells from mice infected intravenously with high doses of Mycobacterium bovis BCG were cultured; these cells showed a marked impairment of the proliferative response to purified protein derivative. Spleen cells from BCG-induced unresponsive mice failed to produce IL-2 despite the fact that normal IL-1 activity was present in the culture. Again, the addition of exogenous IL-2 fully reversed the proliferative unresponsiveness. Thus, the presence of IL-1 does not necessarily induce production of IL-2, and the proliferative unresponsiveness is therefore due to a primary lack of IL-2.     

In vitro cell response of Treponema pallidum-infected rabbits. III. Impairment in production of lymphocyte mitogenic factor.

Production of mitogenic factor was examined in rabbits infected intratesticularly with T. pallidum and in control animals injected with saline or saline extract of normal rabbits' testes. Lymph nodes and spleen from animals killed 2, 6 and 12 weeks after injection were used as the source of lymphocytes, cultured in serum-free medium in the presence of Reiter antigen. The active supernatants of lymph node cells (LNAS) and spleen cells (SPAS) were examined for the presence of mitogenic factor using normal rabbit peripheral lymphocytes. The LNAS of control animals showed a mitogenic index (MI) between 4 and 6 and the infected animals less than 2. The SPAS of infected and control rabbits showed an MI of less than 2. The lower mitogenicity in LNAS of infected and that of SPAS of infected and control animals seems to be due to the presence of inhibitors of DNA synthesis.     

口服免疫耐受大鼠脾淋巴细胞对肾小球系膜细胞中NF-κB p65活性的影响

目的 :探讨口服免疫耐受大鼠脾淋巴细胞对肾小球系膜细胞中NF κBp6 5活性的影响。方法 :将 10只 6～ 8wk龄雌性Wistar大鼠随机分为两组 ,每组 5只。一组用Fx1A抗原灌胃诱导其产生免疫耐受 ,另一组用PBS灌胃作为对照组。 2wk后 ,杀鼠取脾、分离淋巴细胞进行抗原特异性淋巴细胞增殖实验。制备免疫耐受大鼠脾淋巴细胞培养上清 ,用夹心ELISA法测定其中IL 10的水平。将体外培养的系膜细胞用高水平的胰岛素 ,同时加入大鼠的脾淋巴细胞培养上清作用 2 4h。用免疫组化染色及夹心ELISA法检测系膜细胞中NF κBp6 5的活性。结果 :与对照组大鼠相比较 ,口服免疫耐受组大鼠抗原特异性脾淋巴细胞的增殖明显受到抑制 ,其脾淋巴细胞培养上清中IL 10的水平明显升高 (P <0 .0 1)。在体外实验中发现 ,口服免疫耐受大鼠脾淋巴细胞培养上清 ,可抑制胰岛素刺激的系膜细胞内NF κBp6 5的活性 (P <0 .0 5 )。结论 :口服免疫耐受大鼠的脾淋巴细胞 ,可能通过其分泌的IL 10抑制系膜细胞内NF κBp6 5的活性     

Effect of Cyclosporin and Interleukin-2 on the Restoration of in Vitro Immune Responses to Cytomegalovirus

Previous studies have shown that cyclosporin (CSA) inhibits lymphoproliferation to cytomegalovirus (CMV)-infected, glutaraldehyde-fixed, and irradiated fibroblasts (CMVFFx) in vitro. Generation of cytotoxic cell activity is impaired in cultures with CSA, but the induction of suppressor cells is not. In the present studies we tested the ability of interleukin-2 (IL-2) and supernatants of lymphocytes stimulated by CMVFFx with or without CSA (1 microgram/ml) to restore functional activities of lymphocytes from primary cultures treated or not treated with CSA. IL-2 significantly enhanced lymphoproliferation, cell-mediated cytotoxicity to CMV-infected fibroblasts (CMVF), natural killer cell activity, and the activity of cells capable of suppressing the response of fresh autologous cells to CMVFFx of cells derived from control and CSA-treated primary cultures. IL-2 was found in day-2 supernatants of control cultures but not CSA-treated cultures. Day-2 control supernatants were capable of significantly enhancing proliferation and suppressor cell activity but were less efficient at restoring cytotoxic cell function. Day-2 supernatants from CSA-treated cultures were not able to enhance lymphoproliferation or cytotoxic cell function but did induce significant levels of suppressor cell activity. The results indicate the presence of different functional mediators in the culture supernatants. The ability of IL-2 to restore lymphocyte effector functions against a clinically important virus may have important therapeutic implications in the treatment of this viral infection in immunodeficiency diseases and in the restoration of immune competence after transplantation.