The systemic influence of recombinant interleukin 2 on the manifestations of lepromatous leprosy

14 patients with lepromatous leprosy received twice daily injections of 10 micrograms recombinant interleukin 2 (rIL-2), by the intradermal route, in the skin of the back for 8 d (total dose, 160 micrograms). Lymphokine administration was accomplished without drug toxicity, or the development of acute nerve damage. The majority of patients developed nontender axillary lymphadenopathy during the course of treatment. Local injection sites showed progressively larger zones of induration, peaking at 24 h and persisting for many days. Early 12-h reactions were of a macular, erythematous nature and exhibited an increasingly striking diurnal variation. The morning injection sites were three- to fourfold larger in diameter than those placed in the evening (9 am to 9 pm). Systemic manifestations of intradermal rIL-2 administration were noted. Peripheral blood T cells, including CD4+ and CD8+ phenotypes, increased 2-2.5-fold and NK cells increased sixfold. Elevations in [3H]TdR incorporation into peripheral blood mononuclear cells occurred to a variety of mycobacterial antigens, but not to those of Mycobacterium leprae. Within 2 wk, biopsies at sites far removed from the back showed increased infiltration of mononuclear cells in 12 of 14 patients. Immunocytochemistry revealed the presence of newly emigrated CD4+ T cells, monocytes, and dermal CD1+ Langerhans cells. Endothelial cells of small dermal vessels expressed major histocompatibility complex class II determinants on their surface. Transmission electron microscopy of these specimens revealed markedly enlarged endothelial cells with many surface projections extending into the lumen as well as extravasating lymphoid cells. The numbers of acid-fast M. leprae in the peripheral sites were examined by slit smear and in biopsies of matched leprosy lesions taken before and after IL-2 administration. Within 2 mo, slit smears showed a 0.5 log or greater reduction in 12 of 14 patients, with a mean for all patients tested of 0.5 log units. Biopsy specimens showed a 1 log unit or greater reduction in the bacterial index (B.I.) in 6 of 14 patients. Historical controls in this Nepalese population showed a 0.5 log unit reduction after multidrug therapy over a period of 12 mo. Thus, after 8 d of IL-2 injections, a fivefold reduction in B.I. was observed during the first 2 mo of the study. Antibody levels against M. leprae phenolic glycolipid 1 (PGL-1) and lipoarabinomanan B were markedly elevated after IL-2 injections, while PGL-1 antigen levels were reduced. We conclude that the administration of rIL-2 has had a significant effect in decreasing the total body burden of M. leprae.(ABSTRACT TRUNCATED AT 400 WORDS)     

Prolonged treatment with recombinant interferon gamma induces erythema nodosum leprosum in lepromatous leprosy patients

10 patients with borderline and lepromatous leprosy were selected for a prolonged trial with recombinant interferon gamma (rIFN-gamma). Patients received 30 micrograms intradermally for six injections over a 9-d period, and then either 100 micrograms intradermally every 1 mo for 10 mo or every 2 wk for 5 mo (total, 1.2 mg). Erythema nodosum leprosum (ENL) was induced in 60% of the patients within 6-7 mo, as compared with an incidence of 15% per year with multiple drug therapy alone. The mean whole-body reduction in bacterial index over the first 6 mo was 0.9 log units. Cutaneous induration at the intradermal injection sites of greater than or equal to 15 mm predicted the development of a subsequent reactional state. Monocytes obtained from patients receiving the lymphokine demonstrated an increased respiratory burst and a 2.5-5.1-fold increase in tumor necrosis factor alpha (TNF-alpha) secretion in response to agonists. Patients in ENL had an even higher release of TNF-alpha from monocytes as well as high levels of TNF-alpha in the plasma (mean, 2,000 pg/ml). Thalidomide therapy was required to treat the systemic manifestations of ENL. Control of toxic symptoms with thalidomide was associated with a 50-80% reduction in agonist-stimulated monocyte TNF-alpha secretion. IFN-gamma enhanced the monocyte release of TNF-alpha by 3-7.5-fold (agonist dependent) when added to patient's cells in vitro, and this could be suppressed by the in vitro addition of 10 micrograms/ml of thalidomide.     

Widespread intradermal accumulation of mononuclear leukocytes in lepromatous leprosy patients treated systemically with recombinant interferon gamma

Intradermal administration of recombinant interferon gamma (rIFN-gamma) to lepromatous leprosy patients has converted the local histology toward a tuberculoid pattern. However, such changes have been confined to the site of injection. In contrast, in the present study, marked, intradermal accumulation of CD3+, CD4+, CD8+, and CD1a+ T cells and Leu-M5+ mononuclear phagocytes was induced at a distance from the sites of administration, in a dose-dependent manner, by 10 daily intramuscular injections of 10-30 micrograms rIFN-gamma/m2. Mononuclear cell infiltration began within 3 d of onset of rIFN-gamma therapy and persisted at least 8 wk. Intramuscular administration of rIFN-gamma to lepromatous patients receiving concurrent chemotherapy can safely induce widespread histologic features of an upgrading reaction.     

Defective production of monocyte-activating cytokines in lepromatous leprosy

We have examined the capacity of monocytes from patients with leprosy to undergo activation and the capacity of mononuclear cells from these patients to incorporate [3H]thymidine and produce monocyte-activating cytokines. Monocytes from patients with either lepromatous or tuberculoid leprosy were activated by concanavalin A (Con A)-induced mononuclear cell supernatants generated from the leukocytes of a normal person. Monocytes activated by these supernatants strongly inhibited L. pneumophila multiplication, and the degree of inhibition was comparable in both groups of patients. Mononuclear cells from patients with either form of leprosy responded comparably to Con A with vigorous [3H]thymidine incorporation. Mononuclear cells from patients with tuberculoid leprosy also vigorously incorporated [3H]thymidine in response to M. leprae antigens. In contrast, mononuclear cells from patients with lepromatous leprosy did not exhibit significant [3H]thymidine incorporation in response to M. leprae antigens. The capacity of mononuclear cells to generate monocyte-activating cytokines generally paralleled their capacity to incorporate [3H]thymidine in response to Con A and M. leprae. Mononuclear cells from patients with either form of leprosy responded to Con A with the production of cytokines (supernatants) able to activate normal monocytes, expressed by inhibition of L. pneumophila multiplication. However Con A-induced supernatants from patients with lepromatous leprosy were less potent than Con A-induced supernatants from patients with tuberculoid leprosy. Mononuclear cells from patients with tuberculoid leprosy responded to M. leprae antigens with the production of potent monocyte-activating supernatants. In contrast, mononuclear cells from patients with lepromatous leprosy did not produce monocyte-activating cytokines in response to M. leprae antigens. These studies support the hypothesis that the immunological defect in lepromatous leprosy results from a failure to activate mononuclear phagocytes rather than from an intrinsic inability of these cells to be activated. We suggest that the failure to activate mononuclear phagocytes stems from defective production of monocyte-activating cytokines in response to M. leprae antigens.     

Ultrasonographic findings in the livers of patients with lepromatous leprosy

Abdominal ultrasonography, including assessment of the liver, spleen, pancreas, great abdominal vessels, and kidneys, was carried out in seven patients with lepromatous leprosy, six patients with tuberculoid leprosy, and 32 healthy Congolese controls. Abnormal ultrasound findings were predominantly detected in the livers of patients with lepromatous leprosy and included an inhomogeneous echo texture of the hepatic parenchyma in all cases. Furthermore, six patients revealed echo-dense, partly irregular areas up to 1.5 cm X 3 cm in size distributed throughout the liver. These were associated with shadowing and were considered to contain calcium. No abnormal findings were encountered in controls or in patients with tuberculoid leprosy except for one patient with tuberculoid leprosy who had a rounded caudal liver edge. The sizes and volumes of liver, spleen, and kidneys were not different in the three groups.     

In vitro studies on the effect of levamisole in lepromatous leprosy

Our previous studies have demonstrated a defective macrophage response to M. leprae in lepromatous leprosy patients. In the present study we report the restoration of Fc receptor and HLA-DR antigen expression as well as antigen specific macrophage-lymphocyte interaction on treatment with levamisole in vitro. These results indicate that levamisole activates the macrophages which in turn results in an improved cell mediated immune response in lepromatous leprosy. This may also be applicable in other disease situations.     

Suppression of cell-mediated immunity by street rabies virus

Mice lethally infected with street rabies virus failed to develop cytotoxic T cells specific for rabies virus-infected target cells, whereas high levels of cell-mediated cytotoxicity (CMC) were generated after nonfatal infection with the attenuated high egg passage (HEP) or ERA rabies virus strains. Furthermore concurrent infection with street, but not with HEP, rabies virus suppresses development of a primary (but not a secondary) CMC response specific for influenza virus. No cross-reactivity is found between effector T-cell populations from mice immunized with HEP or with influenza virus. It thus appears that street rabies virus, which is not known to replicate in the cells of immune system, induces some general defect in the primary CMC lymphocyte response, though restimulation of memory T-cell populations is unimpaired and there is no defect in antibody formation. Development of fatal rabies may reflect the operation of this selective immunosuppressive mechanism.     

An analysis of in vitro T cell responsiveness in lepromatous leprosy

In lepromatous leprosy, there is extensive replication of Mycobacterium leprae (M. leprae) within dermal macrophages. This lack of microbial resistance has been attributed to a defective cell-mediated immune response to M. leprae antigens. We have examined the in vitro response of T cells to M. leprae to determine if hyporesponsiveness could be reversed. The study included 40 unselected patients from New York and from Colombia, most with the severe lepromatous form of the disease. We first noted that lepromatous leprosy patients were of two types: those unable to respond, as assessed by T cell proliferation and immune (gamma) interferon (IFN-gamma) release, and a second group, exhibiting low but detectable responses relative to tuberculoid controls. When the effect of exogenous recombinant interleukin-2 (IL-2) on the response to M. leprae antigens was compared in the two groups, many of the low responders, but not the nonresponders, showed enhanced proliferation and IFN-gamma release. To evaluate a possible suppressive effect of monocytes, these cells were eliminated with a cell-specific monoclonal antibody and complement. Depletion of monocytes often expanded preexisting weak responses but did not reverse the anergy of the M. leprae nonresponders. The enhancement was not M. leprae-specific, since it was also observed when bacillus Calmette-Guerin was the antigenic stimulus for proliferation and IFN-gamma production. Removal of the suppressor T cell subset, with OKT8 antibody and complement, also did not restore responses in nonresponder patients. We conclude that a sizable number of lepromatous leprosy patients exhibit a low degree of responsiveness to M. leprae and that the responses can be enhanced in vitro with IL-2 or with monocyte depletion. Nonresponsiveness, however, cannot be reversed. Since currently available assays measure the function of previously sensitized T cells, suppressor mechanisms may yet contribute to defective cell-mediated immunity by impairing the initial sensitization to M. leprae antigens.     

Sensitivity to sunburn is associated with susceptibility to ultraviolet radiation-induced suppression of cutaneous cell-mediated immunity

Skin cancer incidence is highest in white-skinned people. Within this group, skin types I/II (sun sensitive/tan poorly) are at greater risk than skin types III/IV (sun tolerant/tan well). Studies in mice demonstrate that ultraviolet radiation (UVR)-induced suppression of cell-mediated immune function plays an important role in the development of skin cancer and induces a susceptibility to infectious disease. A similar role is suspected in humans, but we lack quantitative human data to make risk assessments of ambient solar exposure on human health. This study demonstrates that ambient levels of solar UVR, typically experienced within 1 h of exposure to noonday summer sunlight, can suppress contact hypersensitivity (CHS) responses in healthy white-skinned humans in vivo (n = 93). There was a linear relationship between increase in erythema and suppression of CHS (P < 0.001), and a moderate sunburn (two minimal erythema doses [2 MED]) was sufficient to suppress CHS in all volunteers by 93%. However, a single suberythemal exposure of either 0.25 or 0.5 MED suppressed CHS responses by 50 and 80%, respectively, in skin types I/II, whereas 1 MED only suppressed CHS by 40% in skin types III/IV. The two- to threefold greater sensitivity of skin types I/II for a given level of sunburn may play a role in their greater sensitivity to skin cancer.     

Effect of recombinant human interleukin 2 in experimental murine coccidioidomycosis

The therapeutic effect of recombinant human interleukin 2 (rH IL-2) was assessed in experimental murine coccidioidomycosis by daily IV injection for 30 days of doses ranging decimally from 2.5 × 10¹ to 2.5 × 10⁵ units. The treatment with rH IL-2 had neither adverse nor salutary effects.     

Defective gamma interferon production in leprosy. Reversal with antigen and interleukin 2

Antigen and mitogen-induced gamma interferon (gamma-IFN) production was studied in peripheral blood mononuclear cells from 34 leprosy patients. 17 of 18 lepromatous leprosy and borderline lepromatous patients (LL and BL) failed to release gamma-IFN in response to specific antigen (Mycobacterium leprae) and displayed reduced responses to mitogen (concanavalin A) stimulation. In contrast, cells from six tuberculoid and borderline tuberculoid patients (TT and BT) produced considerable levels of gamma-IFN under the same experimental conditions. Normal controls failed to respond to M. leprae and most displayed good responses to concanavalin A. Mid-borderline patients (BB) showed intermediate levels of gamma-IFN release. gamma-IFN release by lepromatous patients could be partially restored with purified interleukin 2 and M. leprae antigen but not with interleukin 2 alone.     

Analysis of B cell dysfunction in patients with common variable immunodeficiency by using recombinant interleukin 2

Recombinant interleukin 2 (RIL2) induces proliferation and differentiation of the Staphylococcus aureus Cowan I (SAC)-activated normal B cells to immunoglobulin (Ig) producting cells. We applied this finding to an analysis of heterogeneity in the differentiation states of B cells in patients with common variable immunodeficiency (CVI). B cells from 5 of 7 patients with CVI were tested for their ability to proliferate under the stimulation of SAC, or SAC and RIL2, and for their differentiation to Ig producing cells in the presence of SAC plus RIL2. The results suggest that the differentiation status of B cells in CVI could be divided into four states based on their responses to SAC and RIL2. In the first state, no B cell proliferation or differentiation was demonstrated in our assays. B cells in the second state showed normal proliferative responses to SAC, but not to SAC plus RIL2, and no differentiation to Ig-secreting cells. The third state showed normal proliferation in response to SAC and SAC plus RIL2, but no differentiation to Ig-secreting cells. The fourth state had a normal proliferation response to SAC and SAC plus RIL2, and normal secretions of IgG and IgM in response to SAC and RIL2. These results show that some B cells in CVI have defects in response to RIL2, and at least in terms of defect of B cells, CVI is heterogeneous.     

In vivo application of recombinant interleukin 2 in the immunotherapy of established cytomegalovirus infection

We have shown in a murine model system for cytomegalovirus (CMV) disease in the immunocompromised host that in vivo application of recombinant human IL-2 (rhIL-2) can enhance the antiviral effect of a limited number of CD8+T lymphocytes, not only in prophylaxis, but also in therapy, when virus has already colonized host tissues. The observed net effect of IL-2 was consistent with the assumption of daily effector population doublings. The prospects for IL-2-supported immunotherapy of established CMV infection depend upon the tissues involved in disease. It appears that the prospects for controlling established CMV adrenalitis are less promising than for a therapy of interstitial CMV pneumonia.     

Enhanced development of atherosclerosis in cholesterol-fed rabbits by suppression of cell-mediated immunity.

T lymphocytes are present in atherosclerotic lesions, but the role of this cell type in the disease process has not been determined. To determine whether cell-mediated immunity influences atherogenesis, New Zealand White rabbits fed a cholesterol-supplemented diet (0.5% wt/wt) were treated with cyclosporin A (n = 20) or vehicle alone (n = 16) for 12 wk. The dose of cyclosporin A was adjusted so that a blood concentration between 100 and 200 ng/ml was maintained to achieve a selective action T-lymphocytes. Effectiveness of immunosuppression in cyclosporin A-treated rabbits was confirmed by allogeneic skin graft survival. Cyclosporin A administration did not affect total plasma lipid concentrations, body weight, or renal function. Percentage of aortic intimal area covered with atherosclerotic lesions was increased significantly by immunosuppression in both the arch region (75 +/- 3% [mean +/- SEM] compared with 60 +/- 5% in controls; P < 0.01) and the thoracic region (47 +/- 7% vs 27 +/- 6%; P = 0.04). Enhanced atherogenesis was not associated with diminished numbers of T lymphocytes in lesions, changes in T lymphocyte subtype, or any discernible change in cellular composition. Humoral immune responses to oxidized LDL were similar in the two groups: serum titres of autoantibodies against malondialdehyde-modified LDL were equivalent. These data demonstrate that cyclosporin A-induced suppression of cell-mediated immunity increased the development of macrophage-rich atherosclerotic lesions in cholesterol-fed rabbits.     

Stimulation of thrombopoiesis in mice by human recombinant interleukin 6.

To date, testing of various cytokines for the stimulation of blood cell production has not demonstrated a consistent effect on peripheral platelet levels. In this report, we provide evidence that human recombinant IL-6 increased platelet production in mice, as measured by both peripheral platelet levels and [75Se]selenomethionine (75SeM) incorporation into newly forming platelets. Peripheral white blood cell counts also were increased, but only to a modest extent, and hematocrit values were unchanged. A dose-response relationship between the amount of IL-6 administered and platelet count, 75SeM incorporation, and white blood cell count was demonstrated. Detectable megakaryocyte and granulocyte-macrophage colony-forming cells in mice that had received IL-6 also were increased in both bone marrow and spleen. These results demonstrate the ability of a purified, recombinant protein to stimulate platelet production in vivo.     

Administration of recombinant interleukin 2 in vivo induces a polyclonal IgM response

We studied the potential immunoenhancing effects of high doses of rIL-2 on murine T and B cell functions in vivo. Injection of rIL-2 caused a threefold or more increase in the frequencies of antigen-specific proliferative T cells, suggesting that rIL-2 initiated a polyclonal T cell response. In primary and secondary humoral immune responses, administration of rIL-2 in vivo selectively enhanced the production of IgM antibodies, whereas the IgG response was unaffected. Coadministration of rIL-2 with antigen failed to induce an isotype switch from IgM to IgG in genetically low-responding mice. Interestingly, in mice treated with rIL-2 alone (in the absence of exogenous antigen), polyclonal IgM production was induced. Polyclonal IgM production of lesser magnitude was found when mice were immunized with specific antigen in the absence of exogenous rIL-2, suggesting that local IL-2 concentrations in a primary immune response might be sufficient to elicit a polyclonal IgM response.     

The effect of oxisuran on differential inhibition of cell-mediated immunity.

Oxisuran, 2-[(methylsulfinyl) acetyl] pyridine suppressed allogeneic skin graft rejection in rats. In PHA responses and one way mixed lymphocyte culture, suppression of cell-mediated immunity was indicated. However, little inhibition of PFCs was observed with Oxisuran, and unlike Azathioprine or Neocarzinostatin, Oxisuran did not concomitantly suppress antibody-producing system in rats. These data suggest that selective suppression of cell-mediated immunological responses by Oxisuran is possible in rats, and Oxisuran may be a better immunosuppressant for clinical organ transplantation.     

脓毒症中细胞免疫紊乱的机制

脓毒症是临床危重患者主要的死亡原因之一,在美国每年约有75万脓毒症患者,其中21.5万患者终因脓毒症而死亡。随着对脓毒症病理生理过程认识的加深和现代分子生物学技术的应用,人们对于脓毒症的发病机制有了更深的了解。大量研究表明,脓毒症的发生与免疫功能紊乱密切相关。因此,深入探讨脓毒症中免疫功能紊乱的病理生理基础,可进一步阐明脓毒症的发病机制,并为其预防和治疗开拓新的思路。     

The cutaneous infiltrates of leprosy. A transmission electron microscopy study

The dermal lesions of 18 patients with leprosy have been examined by transmission electron microscopy. The patients exhibited a spectrum of disease from polar lepromatous to polar tuberculoid with intermediate stages in various states of therapy and relapse. The nature and quantities of inflammatory cells and bacteria have been determined by electron microscopy to supplement previous light and fluorescence microscopy studies. Lepromatous leprosy was characterized by many parasitized foam cells containing large, multibacillary vacuoles with intact, osmiophilic Mycobacterium leprae: Bacteria were embedded in an electron-lucent matrix. No extracellular bacteria were evident. Only small numbers of scattered lymphocytes were found. As one approached the borderline state, smaller numbers of bacilli were present as singlets and doublets in small vacuoles of macrophages. The more reactive forms showed increasing bacillary fragmentation, larger numbers of lymphoid cells, and an occasional epithelioid cell. At the tuberculoid end of the spectrum, clear evidence of an exuberant lymphocyte response was evident. Large numbers of T cells with extremely long and complex filipodia were closely associated with epithelioid and multinucleated giant cells. Many of the mononuclear phagocytes appeared nonviable, and areas of necrosis were evident. Bacillary remnants were scarce and the cytoplasm of the epithelioid cells contained occasional dense bodies and many stacks of endoplasmic reticulum and mitochondria. These results suggest that Leu 3a/OKT4 helper cells may be capable of driving the effector function of mononuclear phagocytes. This would lead to a significant microbicidal effect on M. leprae, perhaps through the production of toxic oxygen intermediates.