Addition of interleukin-2in vitro augments detection of lymphokine-activated killer activity generatedin vivo

Summary Thein vivo administration of repetitive weekly cycles of interleukin-2 (IL-2) to patients with cancer enhances the ability of freshly obtained peripheral blood lymphocytes (PBL) to lyse both the natural-killer(NK)-susceptible K562 and the NK-resistant Daudi targets. Lysis of both targets is significantly augmented by inclusion of IL-2 in the medium during the cytotoxicity assay. This boost is much greater for cells obtained following thein vivo IL-2 therapy than for cells obtained prior to the initiation of therapy or for cells from healthy control donors. In addition to direct lytic activity, the PBL obtained followingin vivo IL-2 show a rapid increase in lymphokine-activated killer (LAK) activity with more prolongedin vitro IL-2 exposure, indicating that LAK effectors primedin vivo respond with secondary-like kinetics to subsequent IL-2in vitro. Lymphocytes from healthy control individuals, cultured in IL-2 under conditions attempting to simulate thein vivo IL-2 exposure, function similarly to PBL obtained from patients following IL-2, in that low-level LAK activity was significantly boosted by inclusion of IL-2 during the cytotoxic assay and the cells also responded with secondary-like kinetics to subsequent IL-2in vitro. The augmentation of the LAK effect was also dependent on the dose of IL-2 added during the 4-h⁵¹Cr-release cytotoxicity assay, with higher doses of IL-2 having a more pronounced effect. While continuous infusion of IL-2 induces a greater cytotoxic potential per milliliter of blood obtained from patients, the peak serum IL-2 levels attained are greater with bolus IL-2 infusions. These pharmacokinetic results, together with the IL-2 dose dependence of LAK activity generatedin vivo shown in this report, suggest that a combination of treatment with bolus IL-2 infusions superimposed on continuous IL-2 infusion may transiently expose IL-2 dependent LAK cells, activatedin vivo, to higher concentrations of IL-2, facilitating theirin vivo cytotoxic potential.This work was supported by NIH contract NO1 CM-47669-02, NIH grants CA-32685, RR-031086, NO1 CM-47669-03, and American Cancer Society grant CH-237     

Natalizumab Exerts Direct Signaling Capacity and Supports a Pro-Inflammatory Phenotype in Some Patients with Multiple Sclerosis

Natalizumab is a recombinant monoclonal antibody raised against integrin alpha-4 (CD49d). It is approved for the treatment of patients with multiple sclerosis (MS), a chronic inflammatory autoimmune disease of the CNS. While having shown high therapeutic efficacy, treatment by natalizumab has been linked to progressive multifocal leukoencephalopathy (PML) as a serious adverse effect. Furthermore, drug cessation sometimes induces rebound disease activity of unknown etiology. Here we investigated whether binding of this adhesion-blocking antibody to T lymphocytes could modulate their phenotype by direct induction of intracellular signaling events. Primary CD4⁺ T lymphocytes either from healthy donors and treated with natalizumab in vitro or from MS patients receiving their very first dose of natalizumab were analyzed. Natalizumab induced a mild upregulation of IL-2, IFN-γ and IL-17 expression in activated primary human CD4⁺ T cells propagated ex vivo from healthy donors, consistent with a pro-inflammatory costimulatory effect on lymphokine expression. Along with this, natalizumab binding triggered rapid MAPK/ERK phosphorylation. Furthermore, it decreased CD49d surface expression on effector cells within a few hours. Sustained CD49d downregulation could be attributed to integrin internalization and degradation. Importantly, also CD4⁺ T cells from some MS patients receiving their very first dose of natalizumab produced more IL-2, IFN-γ and IL-17 already 24 h after infusion. Together these data indicate that in addition to its adhesion-blocking mode of action natalizumab possesses mild direct signaling capacities, which can support a pro-inflammatory phenotype of peripheral blood T lymphocytes. This might explain why a rebound of disease activity or IRIS is observed in some MS patients after natalizumab cessation.     

Imaging pattern of previously in vitro sensitized and interleukin-2 expanded autologous lymphocytes in human cancer

In vivo patterns of lymphocytes sensitized against autologous tumor (in vitro) were studied in seven patients with metastatic cancer as a potential candidate for an alternative method of radioimmunodetection and adoptive immunocytotherapy. Peripheral blood lymphocytes (PBL) were either activated in Interleukin-2 (IL-2) [lymphokine activated killer (LAK) cells]or sensitized against autologous tumor cells by in vitro co-culture (IVC) and expanded in IL-2 (educated cells); both were then labelled with ¹¹¹In. Labelled autologous cells (1 × 10⁷−5 × 10⁸) were administered to patients and biodistribution studied by imaging under a gamma camera at various time intervals. In 4/7 cases, imaging with the educated cells showed concentrations of radioactivity at sites that correlated positively with clinically detectable metastatic tumor. By contrast, only one instance of positive uptake was seen with the LAK cells. Other than slight fever in three cases, infusions of labelled PBL were well tolerated. Educated lymphocytes were cytotoxic against autologous tumor cells and the cytotoxic reactivities of the educated cells were maintained in continuous culture in IL-2 for 4–6 weeks. Evidence of accumulation of radiolabelled educated autologous cells at a significantly higher frequency than that of the LAK cells suggests that in vitro expanded educated PBL might be better candidates for radioimmunodetection of human cancer, and continuous cultures of such educated autologous PBL might be sources for repeated administration of these effector cells.     

Influence of schedule on the therapeutic efficacy of chemoimmunotherapy with doxorubicin and interleukin-2

Combinations of chemotherapeutic agents with recombinant interleukin-2 are currently under investigation in Phase I/II clinical trials as a possible means of improving response rates for metastatic melanoma, breast cancer, non small cell lung and head/neck carcinomas. As chemotherapy often induces marked immune suppressionin vivo, the way in which these agents are combined may be of critical consideration to the therapeutic outcome. Using a rat tumour model, this study aimed to define an optimal schedule for the combined administration of doxorubicin (DOX) with interleukin-2 (IL-2). DOX (4.5 mg/kg bolus i.v.) was administered 24 hours before, during, or 24 hours after, IL-2 immunotherapy (1 x 10⁵ Cetus U/rat/day for 5 days continuous i.v. infusion) to WAG rats bearing hind limb solid colonic adenocarcinoma implants. Tumour measurements taken over the 4 week study period revealed that there was no significant difference in tumour growth inhibition between the three schedules. Furthermore, DOX invariably caused a marked suppression in the rebound lymphoproliferation after cessation of IL-2 therapy (P < 0.001). These results demonstrate that the therapeutic efficacy of the DOX/IL-2 combination is not influenced by the schedule for the administration of these agents within the times of administration investigated in this study.     

Correlation of neutrophil and monocyte derived interleukin-1 receptor antagonist and interleukin-8 with colitis severity in the rabbit

Activated neutrophils and monocytes produce interleukin (IL)-8, a pro-inflammatory chemokine, but also IL-1 receptor antagonist (IL-1ra), which is an anti-inflammatory cytokine. We were interested to see the profiles of IL-8 and IL-1ra in the colonic tissue and in the peripheral blood leukocytes (PBL) during the development of immune complex induced colitis in rabbits. IL-1ra and IL-8 in PBL were measured in 26 rabbits at time 0 h, 24 h, and 48 h after induction of colitis. The colons were removed at 48 h for measuring myeloperoxidase (MPO), ulcer area, IL-1ra and IL-8. Epithelial damage, crypt abscess formation and leukocyte infiltration of the colonic tissue were major features of this colitis model. During the development of colitis, there was an increase in circulating neutrophils and monocytes (P < 0.0001), but not lymphocytes. Likewise, elevated amounts of IL-1ra (P = 0.0001) and IL-8 (P = 0.0219) production by PBL were observed following induction of colitis. Flow cytometry revealed major source of IL-1ra was monocytes, while the main sources of IL-8 were neutrophils and monocytes. There was correlation between MPO and ulcer area (R_s = 0.6327, P < 0.0001). At 24 h, PBL from MPO^High group (n = 11) showed increased IL-1ra (P = 0.027) and IL-8 (P = 0.0128) levels vs MPO^Low group (n = 15). IL-8 production by PBL showed correlation with tissue MPO (R_s = 0.4273, P = 0.0295). The colitis in this model was associated with an increase in circulating monocytes and neutrophils, which released increased amounts of IL-8 and IL-1ra. Further, IL-8 and IL-1ra showed correlation with the severity of colitis. These observations should significantly further understandings on the role of neutrophils and monocytes in the immunopathogenesis of ulcerative colitis.     

MicroRNA-26a-mediated regulation of interleukin-2 expression in transformed avian lymphocyte lines

Background  

Micro(mi)RNAs are a class of small non-coding RNAs that play critical roles in the induction of various cancers, including lymphomas induced by oncogenic viruses. While some of the miRNAs are oncogenic, miRNAs such as miR-26a are consistently downregulated in a number of cancers, demonstrating their potential tumor suppressor functions. Global miRNA expression profiles of a number of virus-transformed avian lymphoma cell lines have shown downregulation of gga-miR-26a expression, irrespective of molecular mechanisms of transformation or the viral aetiology. The neoplastic transformation of lymphocytes by many viruses accompanies high levels of proliferative responses, mostly mediated through cytokines such as IL-2. Chicken IL-2 can modulate T-cell proliferation and cytotoxicity in vitro and in vivo and dysregulation of IL-2 expression is observed in diseases such as leukaemia.     

Development of a B-cell maturation antigen-specific T-cell antigen coupler receptor for multiple myeloma

Background aimsT cells engineered with synthetic receptors have delivered powerful therapeutic results for patients with relapsed/refractory hematologic malignancies. The authors have recently described the T-cell antigen coupler (TAC) receptor, which co-opts the endogenous T-cell receptor (TCR) and activates engineered T cells in an HLA-independent manner. Here the authors describe the evolution of a next-generation TAC receptor with a focus on developing a TAC-engineered T cell for multiple myeloma.MethodsTo optimize the TAC scaffold, the authors employed a bona fide antigen-binding domain derived from the B-cell maturation antigen-specific monoclonal antibody C11D5.3, which has been used successfully in the clinic. The authors first tested humanized versions of the UCHT1 domain, which is used by the TAC to co-opt the TCR. The authors further discovered that the signal peptide affected surface expression of the TAC receptor. Higher density of the TAC receptor enhanced target binding in vitro, which translated into higher levels of Lck at the immunological synapse and stronger proliferation when only receptor–ligand interactions were present.ResultsThe authors observed that the humanized UCHT1 improved surface expression and in vivo efficacy. Using TAC T cells derived from both healthy donors and multiple myeloma patients, the authors determined that despite the influence of receptor density on early activation events and effector function, receptor density did not impact late effector functions in vitro, nor did the receptor density affect in vivo efficacy.ConclusionsThe modifications to the TAC scaffold described herein represent an important step in the evolution of this technology, which tolerates a range of expression levels without impacting therapeutic efficacy.     

The polybacterial lysate olimunostim modulates lymphocyte functionin Vitro and restores depressed cellular immunityin Vivo

Immunobiological activity of the polybacterial lysate Olimunostim (P. acnes, K. pneumoniae, S. aureus) was examined by investigating its effects on murine lymphocytes. When added toin vitro lymphocyte cultures, Olimunostim induced interleukin-2 (IL-2) biological activity (in a 2-d culture) and subsequently potentiated lymphocyte proliferation (on day 3); the latter effect was dependent on the presence of adherent cells.In vivo, significant enhancement of lymphocyte reactivity to T-mitogens and increase of CD4+ helper-inducer T lymphocytes were observed 3 d after a subcutaneous application of Olimunostim to mice with cellular immune deficiency. These results confirm the modulatory properties of Olimunostim towards lymphocytes bothin vitro andin vivo, which may form a basis for its clinical application.     

Different individual immune responses elicited by in vitro immunization

We have previously demonstrated that the addition of muramyl dipeptide (MDP), interleukin-2 (IL-2) and IL-4 effectively raises antibody production from L-Leucyl-L-leucine methyl ester (LLME)-treated human peripheral blood lymphocytes (PBLs) against specific soluble antigen when immunized in vitro. However, PBLs from individual donors were separate optimal conditions regarding concentrations for IL-2 and IL-4, which in turn required us to optimize each individual PBLs to effectively produce antigen specific human antibody by in vitro immunization. These individual differences in the requirement for IL-2 and IL-4 reflects the differences in individual immune responses against a specific soluble antigen, which can be elicited by in vitro immunization. In the present study, we investigated these individual differences in the requirement for IL-2 and IL-4 to induce antibody productionin vitro in the PBLs of 12 volunteers (9 healthy donors and 3 allergenic patients). IL-2 requirements for antibody production varied dependent upon each donor, while higher amounts of IL-4 inhibited IgM and IgG production in all of the healthy donors. However, some of the characteristic features for PBLs donated from allergenic included lowered IgM production compared to PBLs derived from healthy donors, and very high IgE production in the absence of cytokines and allergen. These results demonstrate that the sensitivity of PBLs against antigen sensitization differs between healthy donors and atopic patients, which suggests that the frequency of antigen sensitization might be reflected in differing activation states and/or differing subpopulations of lymphocytes in vivo. This revised version was published online in August 2006 with corrections to the Cover Date.     

Variable Chlorophyll a Fluorescence and CO(2) Uptake in Water-Stressed White Spruce Seedlings

Regulation of photosynthetic activity can contribute to the prevention of photodamage in stress resistant plants during exposure to drought or low temperatures. Responses to increasing levels of water stress were examined in seedlings of the stress resistant forest conifer, white spruce (Picea glauca [Moench.] Voss). Some seedlings were grown under aseptic in vitro conditions and others in pots. In relatively resistant in vivo seedlings, photosynthetic activities changed slowly in response to increasing water stress. Highly sensitive in vitro seedlings responded to water deficits similarly to in vivo seedlings but over a much shorter time scale. Fluorescence, CO₂ exchange, and stomatal conductance data reported here suggest possible mechanisms for the regulation of photochemical activity in these plants.     

Clinical and immunological effects of human recombinant interleukin-2 given by repetitive weekly infusion to normal dogs

Four normal adult dogs received two consecutive weekly cycles of human recombinant interleukin-2 (IL-2) by continuous infusion for 4 days/week. The dose of IL-2 given to each dog was 3×10⁶ units m^–2 day^–1. Toxicities consisted of mild vomiting, diarrhea, and lethargy to varying degrees in all the dogs. These side-effects were reversed when the treatment was discontinued. Fever, tachypnea, and weight gain were not seen. A marked lymphocytosis and eosinophilia developed in all dogs after completion of each course of IL-2 (resulting in a more than sevenfold increase in each cell type) and persisted for more than 1 month in some. Fresh peripheral blood lymphocytes (PBL) obtained during this lymphocytosis mediated enhanced in vitro lysis of a natural-killer-cell-sensitive canine tumor cell line (CTAC). The in vitro proliferative responses of these same PBL to IL-2 could be detected earlier, progressed faster, and involved more cells than PBL tested prior to IL-2 infusion. Thus, a relatively well-tolerated regime of IL-2 in dogs can induce dramatic increases in lymphocyte numbers and activation, which is associated with augmentation of their in vitro antitumor reactivity. The clinical effectiveness of this immunotherapeutic approach remains to be tested in tumor-bearing dogs where it could serve as a relevant large-animal model for immunotherapy of cancer with IL-2.This work was supported by grants from the University of Wisconsin Graduate School. University of Wisconsin School of Veterinary Medicine Companion Animal Fund, NIH CA-32685, CM-87290, and American Cancer Society CH-237     

In vivo anti-inflammatory effects of the M20 IL-1 Inhibitor: II. Effects on serum reactants

We have previously described an IL-1 Inhibitor derived from the M20 myelomoncytic cell line. This line also secretes several molecules of IL-1. We have shown that this factor is specific to IL-1in vitro, as well asin vivo. In vitro IL-1 induced proliferative responses of mouse thymocytes, human T cells and fibroblasts and IL-1 stimulated PGE₂ secretion from fibroblasts, were all inhibited by the M20 IL-1 Inhibitor.In vivo, the IL-1 Inhibitor reduced parameters of acute inflammation such as fever, leukocytosis and local inflammation. This study describes additional effects of the M20 IL-1 Inhibitor on inflammatory serum reactants. Levels of corticosterone and fibrinogen were increased by injection of IL-1, and decreased by the IL-1 Inhibitor. IL-1 reduced zinc and iron plasma levels and elevated copper plasma levels. The M20 IL-1 Inhibitor reversed these changes in a dose dependent manner. Similar effects produced by IL-6 and TNF were unaffected by the M20 IL-1 Inhibitor. Our results indicate that the M20 IL-1 Inhibitor acts specifically on IL-1 induced responsesin vivo. Therefore we conclude that this IL-1 Inhibitor has a great potential as an anti-inflammatory agent.Abbreviations IL-1 Interleukin 1 - IL-6 Interleukin 6 - IL-1ra Interleukin 1 receptor antagonist - TNF tumor necrosis factor     

The Arabidopsis CERK1‐associated kinase PBL27 connects chitin perception to MAPK activation

Perception of microbe‐associated molecular patterns by host cell surface pattern recognition receptors (PRRs) triggers the intracellular activation of mitogen‐activated protein kinase (MAPK) cascades. However, it is not known how PRRs transmit immune signals to MAPK cascades in plants. Here, we identify a complete phospho‐signaling transduction pathway from PRR‐mediated pathogen recognition to MAPK activation in plants. We found that the receptor‐like cytoplasmic kinase PBL27 connects the chitin receptor complex CERK1‐LYK5 and a MAPK cascade. PBL27 interacts with both CERK1 and the MAPK kinase kinase MAPKKK5 at the plasma membrane. Knockout mutants of MAPKKK5 compromise chitin‐induced MAPK activation and disease resistance to Alternaria brassicicola. PBL27 phosphorylates MAPKKK5 in vitro, which is enhanced by phosphorylation of PBL27 by CERK1. The chitin perception induces disassociation between PBL27 and MAPKKK5 in vivo. Furthermore, genetic evidence suggests that phosphorylation of MAPKKK5 by PBL27 is essential for chitin‐induced MAPK activation in plants. These data indicate that PBL27 is the MAPKKK kinase that provides the missing link between the cell surface chitin receptor and the intracellular MAPK cascade in plants.     

Lymphocytes infiltrating colorectal cancer have low proliferative capacity but can secrete normal levels of interferon γ

Significant numbers of infiltrating mononuclear cells are commonly observed in solid tumours, although their role in restricting tumour growth is not clear. Tumour-infiltrating lymphocytes (TIL) from 38 patients with colorectal cancer, in parallel with peripheral blood lymphocytes (PBL), were assayed to determine their ability to proliferate in response to concanavalin A (ConA), interleukin-2 (IL-2), ConA+IL-2, phorbol 12-myristate 13-acetate (PMA)+ionomycin (IOM), and staphylococcal enterotoxin B (SEB). These reagents were selected to give a range of weak to strong proliferative responses either via or independent of the T cell receptor. Proliferation of TIL was significantly lower than that of PBL in all cultures: ConA (P<0.001), IL-2 (P=0.002), ConA+IL-2 (P<0.001), PMA+IOM (P<0.001), SEB (P=0.002). In addition to the low proliferative capacity of TIL, production of cytokines by TIL may also play a role in control of tumour growth. We have assayed IFN production in the supernatants from 16 paired TIL and PBL cultures, and tumour necrosis factor (TNF) in 6 paired cultures. TNF concentrations were significantly lower in TIL cultures than in PBL cultures stimulated with ConA (P<0.05), but no different in control or IL-2 stimulated cultures. IFN levels did not significantly differ between PBL and TIL cultures, indicating that despite the restricted proliferative capacity of TIL, these cells remain capable of secreting significant amounts of IFN.     

Impairment in proliferation,lymphokine production and frequency distribution of mitogen-responsive and interleukin-2-producing cells in Hodgkin's disease

Summary In this paper, we have correlated the ability of peripheral blood lymphocytes (PBL) from Hodgkin's Disease patients to proliferate in response to a mitogen, phytohaemagglutinin (PHA), with production of lymphokines interleukin-2 (IL-2) and interferon (IFN), accumulating in the activated lymphocyte culture supernatants. We have also studied the frequency distribution of PHA-responsive and IL-2-producing T cells from PBL using limiting-dilution analysis. We observed that the levels of IL-2 and IFN in the supernatants of activated lymphocytes from patients with Hodgkin's disease were significantly reduced compared to those of healthy donors. Substage-B patients showed marked reduction in the ability to produce IFN. Levels of IL-2 and IFN in the culture supernatants of PBL from Hodgkin's disease patients correlated positively with proliferative responses, when analysed by linear regressison (r = 0.79 andr = 0.60 respectively). However, production of the two lymphokines by activated lymphocytes from the same patients did not correlate (r = +0.04). Further, the frequencies of PHA-responsive cells and IL-2-producing cells in the PBL of patients with Hodgkin's disease (ranges 1/111–1/554 and 1/3009–1/6709 respectively) were also less than those of the healthy donors (ranges 1/80–1/181 and 1/761–1/1828 respectively). Proliferation, IL-2 production in bulk cultures and frequencies of PHA-responsive and IL-2-producing cells correlated well in individual healthy donors. Whereas, one patient (BC 11 214) with a frequency of PHA-responsive cells within normal limits had a very low frequency of IL-2-producing cells. Taken together, the results indicate abnormalities in cytokine production and frequency distribution of cells required for amplification of immune response in patients with Hodgkin's disease.     

Cell-mediated cytotoxicity can be regulated by p53 tumor suppressor gene activity in vitro

Summary— The wild-type human p53 tumor suppressor gene was tested for its ability to modulate cytotoxic activity of in vitro activated peripheral blood lymphocytes. Peripheral blood mononuclear cells (PBMCs) were stimulated by phytohemagglutinin (PHA), interferon α2b (IFNα2b), interleukin 2 (IL-2) or their combinations to induce cytotoxicity. This stimulation significantly increased the percentage of cells expressing p53, which was at its maximum when induced by IL-2 combined with IFNα2b. The role of p53 in the modulation of different aspects of cytotoxic activity of these cells was analyzed by studying the effects of p53 abrogation by antisense oligonucleotide (p53 AS) treatment in comparison with p53 sense or scrambled (missense) oligonucleotide (p53 S or p53 MS) treatment. We show that p53 plays a key role through induction of apoptosis in target cells (tumor necrosis factor pathway) rather than through osmolytic degeneration (perforin pathway) which is only slightly increased by p53 abrogation. Meanwhile, in vitro abrogation of p53 expression in PBL was found to be accompanied by an increase of CD8+ lymphocytes and an important increase of the CD56 ‘bright’ NK cell sub-population.     

c-myc gene expression and interleukin-2 receptor levels in cloned human CD2+,CD3+ and CD2+,CD3- lymphocytes

The levels of c-myc mRNA and interleukin-2 receptors (IL-2 Rec) were studied in human peripheral blood lymphocytes (PBL); mature CD2+,CD3+ T cell clones and CD2+,CD3- natural killer (NK) cell clones, and CD2+,CD3+ and CD2-,CD3- T lymphoma cell lines. A transient induction of the expression of c-myc and IL-2 Rec was observed in PBL after activation with phytohemagglutinin (PHA). Expression of c-myc and IL-2 Rec was also found in the CD2+,CD3+ and CD2+,CD3- clones. The CD2+,CD3+ showed higher levels of c-myc mRNA and IL-2 Rec than the CD2+,CD3- clones. In three T lymphoma cell lines constitutively high levels of c-myc mRNA but no IL-2 Rec were found. Only in JURKAT (CD2+,CD3+), c-myc mRNA levels could be further enhanced by PHA. These results suggest that in the presence of PHA, expression of c-myc and IL-2 Rec is induced via the CD3 receptor, and in the absence of PHA and/or the CD3 receptor alternative routes of induction are involved.     

The role of T cell interleukin-17 in conducting destructive arthritis: lessons from animal models

Interleukin-17 (IL-17) is a T cell cytokine spontaneously produced by cultures of rheumatoid arthritis (RA) synovial membranes. High levels have been detected in the synovial fluid of patients with RA. The trigger for IL-17 is not fully identified; however, IL-23 promotes the production of IL-17 and a strong correlation between IL-15 and IL-17 levels in synovial fluid has been observed. IL-17 is a potent inducer of various cytokines such as tumor necrosis factor (TNF)-α, IL-1, and receptor activator of NF-κB ligand (RANKL). Additive or even synergistic effects with IL-1 and TNF-α in inducing cytokine expression and joint damage have been shown in vitro and in vivo. This review describes the role of IL-17 in the pathogenesis of destructive arthritis with a major focus on studies in vivo in arthritis models. From these studies in vivo it can be concluded that IL-17 becomes significant when T cells are a major element of the arthritis process. Moreover, IL-17 has the capacity to induce joint destruction in an IL-1-independent manner and can bypass TNF-dependent arthritis. Anti-IL-17 cytokine therapy is of interest as an additional new anti-rheumatic strategy for RA, in particular in situations in which elevated IL-17 might attenuate the response to anti-TNF/anti-IL-1 therapy.     

A change of IL-2 and IL-4 production in patients with Helicobactor pylori infection

Hellcobacter pylori is the most common cause of gastroduodenal inflammation. However, the exact immune pathogenesis is not fully understood. To look for evidence of the immunological mechanism in H. pylori associated disease, we measured cytokine interleukin-2 (IL-2) and IL-4 levels produced by peripheral blood lymphocytes (PBL) and gastric biopsies in 20 subjects with or without H. pylori infection. H. pylori can stimulate IL-2 and IL-4 production from PBL in H. pylori negative as well as H. pylori positive individuals. The spontaneous IL-2 production by PBL and gastric biopsies was greater (p < 0.0025, <0.001)in H. pylori negative individuals than that in H. pylori infected patients. Increased IL-4 levels from PBL in H. pylori infected patients were found in the presence of H. pylori (p < 0.0025). An increased spontaneous production of IL-4 from gastric biopsies was also observed in H. pylori infected patients (p < 0.025). In conclusion, an enhanced type 2 cytokine production was observed in H. pylori infected patients, which may be responsible for H. pylori chronic infection.     

Haptoglobin and the Th1/Th2 balance: hints from in vitro and in vivo studies

Abstract

A variety of immunomodulatory effects have previously been attributed to haptoglobin (Hp). These are supposed to be partly mediated through binding of Hp to CD11b. In the present study, we assessed its effects on T-helper (Th) cytokine production following both in vitro and in vivo stimulation of T-cells. Hp exhibits a dose-dependent inhibitory effect on human T lymphocyte release of the Th2 cytokines (IL-4, IL-5, IL-10 and IL-13) in vitro, whereas it has no clear effect on Th1 cytokine (IL-2 and IFN-γ) release. When administered an anti-CD3 monoclonal antibody, Hp knockout mice produced more IL-4 and less IFN-γ than did their wild-type litter-mates. Our findings imply that Hp may be regarded as a regulator of the Th1/Th2 balance in both human and murine immune systems.