The risk of osteoporosis in oral steroid treatment for nasal polyposis: a systematic review.

BACKGROUND: Systemic glucocorticoids are often used in the treatment of chronic rhinosinusitis with nasal polyps (CRSwNP), and osteoporosis is a well-known complication to steroid treatment, associated with significant morbidity. Nevertheless, the burden of steroid induced osteoporosis is unknown in patients with CRSwNP. We aimed to assess the risk of acquiring osteoporosis caused by oral steroids in patients with CRSwNP, and provide recommendations on future research and guidelines. METHODOLOGY: Cochrane Review Database, EMBASE, Ovid Medline, and PubMed were searched for studies including adult patients with CRSwNP treated with oral steroids. Outcomes were Bone Mineral Density (BMD) and prevalence of fractures in relation to dose and duration of oral steroids. In addition, we reviewed general guidelines for treatment with oral steroids. RESULTS: We identified two studies (n=243) that met the inclusion criteria. Doses and durations of oral steroids were over 5 mg/day for more than 3 months and 1 mg/kg body weight/day for 6 to 10 days for 4 or more courses/year. The prevalence of low bone mass was 39% and 61%, respectively. It was not possible to quantify the overall risk of osteoporosis induced by oral steroids from the studies. No studies evaluated prevalence of fracture. CONCLUSIONS: Registry studies and randomized controlled trials would be needed to assess the risk of osteoporosis in CRSwNP patients and future guidelines should include recommendations regarding preventive treatment and recommendations on doses and durations of oral steroids.

CLinical experience acquired with the efalizumab (Raptiva) (CLEAR) trial in patients with moderate-to-severe plaque psoriasis: results from a phase III international randomized, placebo-controlled trial.

BACKGROUND: Efalizumab (anti-CD11a), a humanized monoclonal antibody, blocks multiple T-cell-dependent functions implicated in the pathogenesis of psoriasis, including T-cell activation, migration to the skin, reactivation in psoriatic skin and interactions with keratinocytes. OBJECTIVES: This multinational, randomized, double-blind, placebo-controlled, parallel-group trial was designed to evaluate the safety and efficacy of subcutaneous efalizumab 1.0 mg kg-1 once weekly for 12 weeks compared with placebo in a population that included high-need patients, defined as those for whom at least two systemic therapies were unsuitable because of lack of efficacy, intolerance or contraindication. PATIENTS/METHODS: Patients with moderate-to-severe plaque psoriasis [involvement of >or=10% of total body surface area and Psoriasis Area and Severity Index (PASI)>or=12.0 at screening] were randomized in a 2:1 ratio to receive efalizumab or placebo. The primary efficacy endpoint was the proportion of patients achieving >or=75% PASI improvement (PASI-75 response) at week 12 in the intention-to-treat population; secondary endpoints included changes in PASI, static Physician's Global Assessment, Physician's Global Assessment of change from baseline and percentage of body surface area affected. Results We enrolled 793 patients (529 received efalizumab and 264 placebo), including 526 high-need patients (342 received efalizumab and 184 placebo). Week 12 PASI-75 rates were 29.5% for efalizumab compared with 2.7% for placebo among high-need patients (P<0.0001) and 31.4% for efalizumab compared with 4.2% for placebo in the full study population (P<0.0001). RESULTS: for all secondary efficacy endpoints showed superiority of efalizumab over placebo in both the high-need and the full populations. Efalizumab demonstrated a favourable safety profile, without evidence of systemic toxicity, in both the high-need group and the overall study population. CONCLUSIONS: The efficacy and safety of efalizumab therapy were comparable between high-need patients and the more general moderate-to-severe psoriasis patient population. In view of its demonstrated efficacy and safety profile, efalizumab represents a valuable option for the treatment of adult patients with moderate-to-severe plaque psoriasis, including high-need patients.

IL-10 augments the IFN-gamma and TNF-alpha induced TARC production in HaCaT cells: a possible mechanism in the inflammatory reaction of atopic dermatitis.

The CC-chemokine TARC is known to be a ligand for the CCR4 receptor which in turn is known to be expressed selectively on the Th(2)-subset of lymphocytes. Atopic dermatitis is generally believed to be a Th(2)-type disease, and TARC has been shown to be expressed in the skin lesions of a murine model of AD. IL-10 is an interleukine generally known for its ability to inhibit cytokine production, however it has been found to be highly expressed in the skin from AD patients. We show in this report that IL-10 is able to augment the TARC inducing effects of TNFalpha and IFNgamma in HaCaT cells, a property that may be important in the determination of the composition of the cells of the inflammation in the skin of AD patients. In addition, we show that the IL10 agonist IT 9302, a nona-peptide from the carboxylic end of IL-10, has the same effect on TARC production from HaCaT cells.

Treatment with a monocolonal antibody to IL-8 attenuates the pleocytosis in experimental pneumococcal meningitis in rabbits when given intravenously, but not intracisternally.

The role of interleukin (IL)-8 as mediator in the recruitment of leucocytes into the CSF was investigated during experimental pneumococcal meningitis. Rabbits were inoculated intracisternally with approximately 10(6) CFU Streptococcus pneumoniae, and treated (i) intravenously with 5 mg of a monoclonal antibody to IL-8 (n = 7) or 5 mg of an isotype control antibody (n = 6); (ii) intracisternally with anti-IL-8, 100 microg (n = 5), 10 microg (n = 4), 1 microg (n = 4), 0.1 microg (n = 2). Ten rabbits served as untreated control group. Intravenous treatment with anti-IL-8 attenuated the pleocytosis significantly compared to untreated rabbits (P < 0.04) or rabbits treated with an isotype control antibody (P < 0.02). In contrast, intracisternal treatment with anti-IL-8 failed to attenuate the pleocytosis (P > 0.05). These results show, that IL-8 plays an important role in the recruitment of leucocytes during experimental pneumococcal meningitis, and that the functional activity of IL-8 in this process appears to be on the bloodstream side of the microvascular endothelium of the brain.

A Th2 chemokine, TARC, produced by keratinocytes may recruit CLA+CCR4+ lymphocytes into lesional atopic dermatitis skin.

Atopic dermatitis is an inflammatory skin disease in which the inflammation is characterized by the influx of lymphocytes into the dermis. It is generally believed that atopic dermatitis is a Th2-type disease, i.e., the T lymphocytes produce interleukin-4, interleukin-5, interleukin-10, and interleukin-13, although it has become evident in recent years that the cytokine profile in the skin changes during the course of the disease towards a Th1-Th2 mixed cytokine profile (interferon-gamma, tumor necrosis factor alpha, and interleukin-2). The lymphocytes that home into the skin express cutaneous lymphocyte-associated antigen, and it has recently been shown that most of the lymphocytes in this population express the chemokine receptor CCR4. CCR4 is the receptor for the CC chemokine TARC (thymus and activation regulated chemokine), and this chemokine is expressed predominantly by keratinocytes in the basal layer of the epidermis of lesional atopic dermatitis skin in mice. In humans, however, it was shown to be expressed in the endothelial cells of the dermis. We have examined the peripheral blood mononuclear cells of atopic dermatitis patients for the expression of cutaneous lymphocyte-associated antigen and CCR4 and compared them with peripheral blood mononuclear cells from normal controls. We found that the proportion of CLA+CCR4+ lymphocytes is upregulated in atopic dermatitis patients. In addition we have examined skin biopsies of lesional and non-lesional skin from atopic dermatitis patients and found that the keratinocytes, but not the endothelial cells, produce TARC in the lesional but not in the nonlesional skin. To gain insight in the stimulatory mechanisms for TARC production in keratinocytes, as previously observed in mice, we cultured HaCaT cells and found that interferon-gamma and tumor necrosis factor alpha work synergistically to induce TARC production. These observations suggest that the induction of TARC production in keratinocytes plays an important role in the late phase skin invasion by CCR4+CLA+ Th2-type lymphocytes in atopic dermatitis.

Beneficial effects of hydrocortisone in a model of experimental acute pancreatitis.

BACKGROUND: Proinflammatory cytokines like TNF-alpha and IL-8 have been thought to play a pivotal role in the propagation of severe acute pancreatitis (AP) and the development of its systemic complications, particularly acute lung injury. OBJECTIVE: To investigate the effects of pretreatment with hydrocortisone on the production of cytokines and the occurrence of acute lung injury in rabbits with AP. METHODS: AP was induced in 17 rabbits by infusion of 5% chenodeoxycholic acid into the pancreatic duct, followed by ductal ligation. The rabbits were allocated to pretreatment with subcutaneous and intravenous hydrocortisone (25 mg/kg, respectively; n = 7) or 0.9% saline (n = 10) 30 min before induction of AP. Rabbits were observed for 12 h. Serum amylase, lipase, TNF-alpha, IL-8, glucose, calcium and leukocyte count were measured every 3 h. At the end of the experimental period, ascitic fluid was collected and tissue specimens from the pancreas, lungs and kidney were obtained. RESULTS: Hydrocortisone pretreatment improved survival from 40 to 100%. Serum TNF-alpha and IL-8 were lower in the hydrocortisone group than in the control group at 6 h (p = 0.006 and p < 0.001, respectively). Hydrocortisone abolished leukopenia (p < 0. 001), hyperamylasemia (p = 0.05), the occurrence of acute lung injury and reduced the volume of ascites. CONCLUSIONS: Our findings suggest a role for TNF-alpha and IL-8 in mediating the progress of AP from a local disease into a systemic illness. Hydrocortisone should be tested experimentally after the induction of AP and clinically as a prophylactic measure to avoid severe AP induced by endoscopic retrograde cholangiopancreaticography.

Eotaxin activates T cells to chemotaxis and adhesion only if induced to express CCR3 by IL-2 together with IL-4.

The transmigration and adherence of T lymphocytes through microvascular endothelium are essential events for their recruitment into inflammatory sites. In the present study, we investigated the expression of CC chemokine receptor CCR3 on T lymphocytes and the capacities of the CC chemokine eotaxin to induce chemotaxis and adhesion in T lymphocytes. We have observed a novel phenomenon that IL-2 and IL-4 induce the expression of CCR3 on T lymphocytes. We also report that CC chemokine eotaxin is a potent chemoattractant for IL-2- and IL-4-stimulated T lymphocytes, but not for freshly isolated T lymphocytes. Eotaxin attracts T lymphocytes via CCR3, documented by the fact that anti-CCR3 mAb blocks eotaxin-mediated T lymphocyte chemotaxis. In combination with IL-2 and IL-4, eotaxin enhances the expression of adhesion molecules such as ICAM-1 and several integrins (CD29, CD49a, and CD49b) on T lymphocytes and thus promotes adhesion and aggregation of T lymphocytes. The eotaxin-induced T lymphocyte adhesion could be selectively blocked by a specific cAMP-dependent protein kinase inhibitor, H-89, indicating that eotaxin activates T lymphocytes via a special cAMP-signaling pathway. Our new findings all point toward the fact that eotaxin, in association with the Th1-derived cytokine IL-2 and the Th2-derived cytokine IL-4, is an important T lymphocyte activator, stimulating the directional migration, adhesion, accumulation, and recruitment of T lymphocytes, and paralleled the accumulation of eosinophils and basophils during the process of certain types of inflammation such as allergy.

Graded experimental acute pancreatitis: monitoring of a renewed rabbit model focusing on the production of interleukin-8 (IL-8) and CD11b/CD18.

OBJECTIVE: To establish and monitor a rabbit model of graded severity of acute pancreatitis to test the hypothesis that interleukin-8 (IL-8) and the adhesion molecule complex CD11b/CD18 are involved in the development of systemic complications in severe acute pancreatitis. METHODS: Acute pancreatitis induction in rabbits by duct ligation with or without infusion of 5.0% or 0.5% chenodeoxycholic acid or 0.9% saline. Control animals underwent laparotomy. The animals were monitored biochemically, histologically and immunohistochemically. RESULT: Increased serum levels of IL-8, tumour necrosis factor alpha (TNF-alpha), amylase and lipase were found in the chenodeoxycholic acid groups when compared with the saline, duct-ligated or control groups. Leukopenia, hypocalcaemia, and hyperglycaemia were marked in the 5.0% chenodeoxycholic acid group as compared to the saline, duct-ligated and control groups. Histologically, the 5.0% chenodeoxycholic acid group manifested a significant degree of pancreatic necrosis and neutrophil infiltration. The lungs of these animals showed acute lung injury and a significant up-regulation of CD11b/CD18. IL-8 was produced in pancreatic acinar and ductal cells. A significantly large output of ascitic fluid was seen in the 5.0% chenodeoxycholic acid group. CONCLUSION: The rabbit models of acute pancreatitis are reliable in that enzymatic and histological evidence of acute pancreatitis with or without systemic complications developed. IL-8 is produced locally in pancreatic acinar and ductal cells and significantly increased in peripheral blood during severe but not mild pancreatitis. The expression of the adhesion molecule complex CD11b/CB18 is significantly increased in lung tissue during severe acute pancreatitis with acute lung injury. IL-8 and CD11b/CB18 are involved in the pathogenesis of severe acute pancreatitis but not of mild oedematous pancreatitis.

Systemic and cell-mediated immune response after laparoscopic and open cholecystectomy in patients with chronic liver disease. A randomized, prospective study.

BACKGROUND: As impaired immune function observed in cirrhotic patients is known to increase the risk of postoperative complications, the immunological response to surgery was investigated. METHODS: Twenty-eight patients with postnecrotic liver cirrhosis or chronic hepatitis C and symptomatic gallstone disease were randomly allocated to laparoscopic (LC) or open cholecystectomy (OC). Changes in concentrations of cytokines (TNF-alpha, IL-1beta, IL-6, IL-8 and IL-10) were followed and the effect of surgical trauma on the distribution of lymphocyte subpopulations (CD3, CD4, CD8, CD16 and CD19) and NK cell cytotoxicity were measured. RESULTS: After OC a decrease in circulating CD3 (p < 0.05) and CD4 (p < 0.05) and an increase in CD19 (p < 0.05) cells were detected in contrast to LC after which only CD16 cells decreased (p = 0.05). The number of CD3 cells was higher after LC than after OC (p < 0.01), whereas the number of CD19 cells was higher after OC than after LC (p < 0.01). NK cell cytotoxicity was reduced after LC (p < 0.05). In cirrhotic patients circulating cytokines were unaffected by OC, whereas TNF-alpha (p < 0.05) and IL-1beta (p < 0.05) were reduced after LC. In chronic hepatitis IL-1beta decreased after OC (p = 0.05) and IL-10 was significantly higher after LC than following OC (p < 0.05). CONCLUSION: The immune response is less pronounced after a laparoscopic procedure compared to a conventional approach in patients with chronic liver disease.

Sodium fusidate and the cytokine response in an experimental model of acute pancreatitis.

BACKGROUND: New therapies designed to downregulate the aberrant immune response associated with severe acute necrotizing pancreatitis (ANP) are being increasingly investigated in different experimental models of ANP. The aim of this study was to test the potential effects of sodium fusidate on the course of severe ANP in rabbits. METHODS: ANP was induced in 20 rabbits by retrograde injection of 5 per cent chenodeoxycholic acid into the pancreatic duct followed by duct ligation. The rabbits were allocated to pretreatment with intravenous physiological saline or sodium fusidate 80 mg/kg 30 min before the induction of ANP. Levels of serum amylase, lipase, tumour necrosis factor (TNF) alpha, interleukin (IL) 8, glucose and calcium, and leucocyte count were measured every 3 h for a total of 12 h. At the end of the experiment, ascitic fluid was collected and the pancreatic, lung and kidney tissues were obtained for histological examination. RESULTS: Pretreatment with sodium fusidate reduced the mortality rate from six of ten to three of ten (P < 005) and reduced the output of ascitic fluid from 5 2 to 2.0 ml/h (P < 0001). Serum levels of TNF-alpha and IL-8 were reduced significantly in the treated group from 5 min up to 9 h after induction of ANP. The leucopenia observed after 3 h in the untreated group was not significantly improved in the group treated with sodium fusidate (P = 0.055). By contrast, both treated and untreated rabbits had similar biochemical changes including levels of amylase, lipase, glucose and calcium as well as similar histological changes in the pancreas and lungs. CONCLUSION: Pretreatment with sodium fusidate resulted in a considerable reduction in mortality rate and ascitic fluid output in rabbits with bile-induced ANP, probably by lowering the TNF-alpha and IL-8 blood levels. However, pretreatment with sodium fusidate did not alter the local or systemic manifestations of ANP. Thus, cytokines other than TNF-alpha and IL-8 are likely to mediate the local and systemic symptoms of ANP.

Tirilazad inhibits surgically induced edema and interleukin-1 production. An experimental study in rats.

The aim of this study was to evaluate the anti-inflammatory effect of tirilazad mesylate on edema and interleukin-1 (IL-1) levels in serum following standardized surgical procedures. Four groups, each containing eight rats, were randomized for treatment as follows: A) no medication, B) low-dose tirilazad, C) high-dose tirilazad, and D) corticosteroids. The animals were examined by nuclear magnetic resonance imaging (NMRI) 24 and 72 hours after surgery and the NMRI data were used in the determination of soft tissue edema. In addition, serum was obtained for analysis of IL-1 levels. Four other groups of animals were subjected to the same treatment regimen as groups A-D), respectively, and 24 hours after surgery the animals were killed, whereafter serum was obtained for analysis of IL-1 levels. The present study demonstrated that low-dose tirilazad significantly reduces soft tissue edema compared with all other treatment regimens 24 hours postoperatively. At 72 hours postoperatively significant reduction of soft tissue edema was achieved at low-dose tirilazad when compared to high-dose tirilazad and steroids. In addition, a significant suppression of the expression of IL-1 was observed at 24 and 72 hours when comparing low-dose tirilazad and the control group.

IT 9302, a synthetic interleukin-10 agonist, diminishes acute lung injury in rabbits with acute necrotizing pancreatitis.

BACKGROUND: Proinflammatory cytokines (eg, tumor necrosis factor [TNF]-alpha, interleukin [IL]-1 and Il- 8) are believed to play an important role in the pathogenesis of acute necrotizing pancreatitis (ANP) and its systemic complications. Recently, IL-10 has emerged as a major anti-inflammatory cytokine, inhibiting the secretion and activities of inflammatory cytokines. Further, a protective effect of IL-10 has recently been shown in experimental acute pancreatitis. The purpose of this study was to test the potential role of a newly developed IL-10 agonist, IT 9302, in a model of ANP in rabbits. METHODS: ANP was induced in 18 rabbits by retrograde injection of 5% chenodeoxycholic acid in the pancreatic duct, followed by duct ligation. The rabbits were allocated to pretreatment with intravenous physiologic saline solution or IT 9302 (200 micrograms/kg) 30 minutes before the induction of ANP. RESULTS: Injection of IT 9302 resulted in a significant reduction in the blood levels of TNF-alpha and IL-8 from 3 to 6 hours. IT 9302 also reduced the amount of ascitic fluid and significantly inhibited neutrophil infiltration and margination, as well as the number of CD11b- and CD18-positive cells in the lung tissues. By contrast, the local pancreatic necrosis, as well as the biochemical changes such as serum amylase, lipase, and calcium, was sever and similar in both groups. Survival was improved significantly after treatment with IT 9302. CONCLUSIONS: As expected, IT 9302 cannot change the degree of ANP induced by 5% bile acid but does reduce mortality rates and the development of acute lung injury, probably through the inhibition of circulating levels of TNF-alpha, IL-8, and the expression of the adhesion molecule complex CD11b/CD18.

A monoclonal anti-interleukin 8 antibody (WS-4) inhibits cytokine response and acute lung injury in experimental severe acute necrotising pancreatitis in rabbits.

BACKGROUND: Interleukin 8 (IL-8) has recently been proposed to have an important role in mediating the development of the systemic sequelae associated with severe acute pancreatitis. AIMS: To define the role of IL-8 in acute pancreatitis by neutralising its effects with a monoclonal anti-IL-8 antibody (WS-4), in a rabbit model of severe acute pancreatitis. METHODS: Acute pancreatitis was induced by retrograde injection of 5% chenodeoxycholic acid into the pancreatic duct and duct ligation. Twenty rabbits were divided equally into two groups: acute pancreatitis controls received physiological saline and the treated group received WS-4, 30 minutes before induction of acute pancreatitis. RESULTS: Pretreatment of animals with WS-4 resulted in significant down regulation of serum IL-8 and tumour necrosis factor alpha (TNF-alpha) from three to six hours after induction of acute pancreatitis (p = 0.011 and 0.047 for IL-8 and 0.033 and 0.022 for TNF-alpha, respectively). In addition, a significant reduction in the CD11b and CD18 positive cells and the amount of interstitial neutrophil infiltration in the lungs from WS-4 treated animals was seen. In contrast, WS-4 did not alter the amount of pancreatic necrosis and the serum concentrations of amylase, lipase, calcium, and glucose. CONCLUSION: WS-4 cannot change the amount of pancreatic necrosis induced by injection of 5% bile acid, but does reduce the acute lung injury, presumably through inhibition of circulating IL-8 and TNF-alpha, and CD11b/CD18 in lung tissue. Therefore, a role of IL-8 in the progression of acute pancreatitis and the development of its systemic complications is suggested.

Monocyte chemotactic and activating factor (MCAF/MCP-1) has an autoinductive effect in monocytes, a process regulated by IL-10.

MCAF (MCP-1) a member of the chemokine-beta-family known to be chemotactic for monocytes is believed to play a significant role in several inflammatory processes, both immuno-pathological disorders, such as atherosclerosis, psoriasis, chronic inflammatory diseases of the liver and lungs, and during the normal immune response against microorganisms. This chemokine is produced spontaneously by monocytes, and in the present article we also demonstrate that MCAF induces its own production in monocytes. The methods used are two dimensional SDS-PAGE gel electrophoresis. Western-blotting and ELISA quantification of supernatant from monocyte cultures stimulated with MCAF (1, 10, 100 ng ml). Also, we found that this process is regulated by IL-10 (100 ng ml). Our results suggest that monocytes migrating to a site of inflammation due to the local production of the chemokine MCAF/MCP-1 further enhance the focal accumulation of monocytes by producing and releasing bioactive MCAF MCP-1.

Neutrophil chemotactic activity in bronchoalveolar lavage fluid of patients with AIDS-associated Pneumocystis carinii pneumonia.

Pneumocystis carinii pneumonia (PCP) is accompanied by an acute inflammatory infiltration of the lung parenchyma. The cellular infiltrate is characterized by inflammatory cells including neutrophils, lymphocytes and macrophages. Furthermore, neutrophilia in bronchoalveolar lavage (BAL) fluid has been shown to confer a poor prognosis in PCP. We therefore investigated the potential of BAL fluid from 17 patients with PCP to induce neutrophil chemotaxis. BAL fluid from patients induced considerable neutrophil chemotactic activity compared to normal controls. Elevated levels of IL-8 were detected in patient samples as compared to controls. A specific anti-IL-8 antibody significantly reduced chemotactic activity of patient samples by more than 50%. In conclusion, IL-8 appears to be a significant participant of neutrophil chemotaxis in AIDS-associated PCP, and may participate in the recruitment of neutrophils to the lung during PCP.

Chemotaxis and IL-8 receptor expression in B cells from normal and HIV-infected subjects.

To date, the activities of the alpha chemokines for human peripheral B cells from normal subjects (N-B cells) or from HIV-infected subjects (HIV-B cells) are not well established. No report on the IL-8R expression on N-B cells and HIV-B cells has been seen. We report in this work that the alpha chemokines IL-8 and growth-regulatory oncogene-alpha (GRO-alpha) induce a chemotactic migration of N-B cells and HIV-B cells via stimulating the IL-8RB on these cells. The chemotaxis of N-B cells can be inhibited by IFN-gamma and IL-2, and augmented by IL-4 and IL-13, whereas TNF-alpha and IL-10 have no influence. The chemotaxis of HIV-B cells can be inhibited by IFN-gamma and IL-2, and augmented by TNF-alpha, IL-4, and IL-10, whereas IL-13 has no influence. IL-8R are expressed more abundantly on freshly isolated HIV-B cells than N-B cells (51% and 15%, respectively). The IL-8R on N-B cells can be down-regulated by IFN-gamma, IL-2, and TNF-alpha (selectively on IL-8RA), and up-regulated by IL-4 and IL-13, whereas IL-10 has no influence. The IL-8R on HIV-B cells can be down-regulated by IFN-gamma and IL-2, and up-regulated by TNF-alpha, IL-4, and IL-10, whereas IL-13 has no influence. Importantly, N-B cell and HIV-B cell chemotaxis toward IL-8 and GRO-alpha can be blocked by anti-IL-8RB polyclonal Ab, but not by anti-IL-8RA polyclonal Ab. Our results demonstrate that IL-8 and GRO-alpha are important inflammatory mediators that stimulate the directional migration and recruitment of B lymphocytes. The migratory behavior and the expression of IL-8R on HIV-B cells and some of the reactions to Th1- and Th2-like cytokines are modified significantly during HIV infection.

Identification of functional domains on human interleukin 10.

Interleukin 10 (IL-10) is a recently described natural endogenous immunosuppressive cytokine that has been identified in human, murine, and other organisms. Human IL-10 (hIL-10) has high homology with murine IL-10 (mIL-10) as well as with an Epstein-Barr virus genome product BCRFI. This viral IL-10 (vIL-10) shares a number of activities with hIL-10. IL-10 significantly affects chemokine biology, because human IL-10 inhibits chemokine production and is a specific chemotactic factor for CD8+ T cells. It suppresses the ability of CD4+ T cells, but not CD8+ T cells, to migrate in response to IL-8. A nonapeptide (IT9302) with complete homology to a sequence of hIL-10 located in the C-terminal portion (residues 152-160) of the cytokine was found to possess activities that mimic some of those of hIL-10. These are: (i) inhibition of IL-1beta-induced IL-8 production by peripheral blood mononuclear cell, (ii) inhibition of spontaneous IL-8 production by cultured human monocytes, (iii) induction of IL-1 receptor antagonistic protein production by human monocytes, (iv) induction of chemotactic migration of CD8+ human T lymphocytes in vitro, (v) desensitization of human CD8+ T cells resulting in an unresponsiveness toward rhIL-10-induced chemotaxis, (vi) suppression of the chemotactic response of CD4+ T human lymphocytes toward IL-8, (vii) induction of IL-4 production by cultured normal human CD4+ T cells, (viii) down-regulation of tumor necrosis factor-alpha production by CD8+ T cells, and (ix) inhibition of class II major histocompatibility complex antigen expression on IFN-gamma-stimulated human monocytes. Another nonapeptide (IT9403) close to the NH2-terminal part of hIL-10 did not reveal cytokine synthesis inhibitory properties, but proved to be a regulator of mast cell proliferation. In conclusion, we have identified two functional domains of IL-10 exerting different IL-10 like activities, an observation that suggests that relatively small segments of these signal proteins are responsible for particular biological functions.