Interleukin 4 (IL) 4 up-regulates gene and surface IL 1 receptor type I in murine T helper type 2 cells

Enhanced immune responses to vaccine antigens in the corneal stroma

To examine the widely accepted dogma that the eye is an immune-privileged organ that can suppress antigen immunogenicity, we explored systemic immune responses to a model vaccine antigen (tetanus toxoid) delivered to six compartments of the rodent eye (ocular surface, corneal stroma, anterior chamber, subconjunctival space, suprachoroidal space, vitreous body). We discovered that antigens delivered to corneal stroma induced enhanced, rather than suppressed, antigen-specific immune responses, which were 18- to 30-fold greater than conventional intramuscular injection and comparable to intramuscular vaccination with alum adjuvant. Systemic immune responses to antigen delivered to the other ocular compartments were much weaker. The enhanced systemic immune responses after intrastromal injection were related to a sequence of events involving the formation of an antigen "depot" in the avascular stroma, infiltration of antigen-presenting cells, up-regulation of MHC class II and costimulatory molecules CD80/CD86, and induction of lymphangiogenesis in the corneal stroma facilitating sustained presentation of antigen to the lymphatic system. These enhanced immune responses in corneal stroma suggest new approaches to medical interventions for ocular immune diseases and vaccination methods.

Combination Vaccination With Tetanus Toxoid and Enhanced Tumor-Cell Based Vaccine Against Cervical Cancer in a Mouse Model

Cervical cancer is the fourth most common cancer in women with an estimated 570,000 new cases in 2018 which constitute about 6. 6% of all cancers in women according to WHO report 2018. Approximately 90% of the 270,000 deaths from cervical cancer in 2015 occurred in low- and middle-income countries. In cervical cancers, which is caused by human papillomavirus (HPV) infection, the expression of HPV 16 E6 and E7 proteins are essential for tumor cell transformation and maintenance of malignancy. Prophylactic vaccines against cervical cancer caused by human papillomavirus have not proven successful. Although virus-like particle-based (VLPs) vaccines have been developed with prophylactic activities to prevent most HPV infections, the therapeutic effect of VLP vaccines has yet to be demonstrated for those who were already infected. A recent study showed that pre-conditioning mice with a potent antigen such as tetanus toxoid significantly improves lymph node homing and efficacy of dendritic cells. Tetanus toxoid has also been used in combination with DNA vaccines designed from tumor based antigens. In the present study, we pre-conditioned mice with tetanus toxoid followed by vaccination with a Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) overexpressing tumor-cell based vaccine (GVAX). We observed that pre-conditioning with tetanus toxoid followed by vaccination with GVAX regressed tumor growth and enhanced the overall survival of the mice. Pre-conditioning with tetanus toxoid enhanced the immune response which was observed by enlarged spleen size, higher proliferation rate of lymphocytes, a higher level of IFN-γ, TNF-α, and IL-4 antigen-specific secretions by the splenocytes. Pre-conditioning with tetanus toxoid increased memory T cell migration into the tumor site and spleen. The antigen-specific cytotoxic T cell lysis percentage was also found to be higher in the group of mice vaccinated with the combination of tetanus toxoid and GVAX. Hence, pre-conditioning with tetanus toxoid prior to vaccination with a tumor-cell based vaccine overexpressing GM-CSF might be an effective strategy for targeting E7-specific HPV-associated cervical malignancy.

Cytokine Research in Depression: Principles, Challenges, and Open Questions

Cytokines have been implicated in the pathology of depression. Currently, the evidence is based on cross-sectional studies and meta-analytic research comparing blood concentrations of T helper type 1 (TH1), T helper type 2 (TH2), pro-inflammatory or anti-inflammatory cytokines of patients with a depressive disorder to those of healthy controls. Additionally, multiple longitudinal studies have investigated cytokine levels during antidepressant treatment. According to the current literature, it seems that peripheral levels of interleukin (IL)-6, IL-10, IL-12, IL-13, and tumor necrosis factor (TNF)-α are elevated and that interferon (IFN)-γ levels are lower in patients with depression compared to healthy controls. However, the overlap of cytokine values between acutely depressed patients, remitted and recovered patients and healthy controls is considerable. Thus, the discriminative power of cytokine concentrations between depressed and non-depressed people is likely weak. Treatment with certain antidepressants appears to decrease peripheral levels of IL-6, IL-10, and TNF-α. However, weight gain-inducing psychopharmacological substances, such as the antidepressant mirtazapine, have been reported to potentially increase the production of pro-inflammatory cytokines. Even though cytokines are often discussed as biomarkers for depression, they have also been shown to be altered in other psychiatric disorders. Moreover, many environmental, social, psychological, biological, and medical factors are also associated with cytokine changes. Thus, cytokine alterations seem extremely unspecific. The interpretation of the results of these studies remains a challenge because it is unknown which type of cells are most responsible for cytokine changes measured in the blood nor have the main target cells or target tissues been identified. The same cytokine can be produced by multiple cell types, and the same cell can produce various cytokines. Additionally, redundancy, synergy, antagonism, and signaling cascades of cytokine signaling must be considered. Cytokines might not be associated with the diagnosis of depression according to the currently used diagnostic manuals, but rather with specific subtypes of depression, or with depressive symptoms across different psychiatric diagnoses. Therefore, the currently available diagnostic systems may not be the ideal starting point for psychiatric cytokine research.

Tumour necrosis factor-α mediates neutrophil migration to the knee synovial cavity during immune inflammation

Tumour necrosis factor (TNF)-alpha, interleukin-1beta, interleukin-8 and leukotriene B4 have an important role on neutrophil recruitment during immune-inflammation. Here we evaluated the participation of several inflammatory mediators on ovalbumin-induced neutrophil recruitment in the knee articular space of immunized rats. Ovalbumin administration in immunized, but not in control, rats induced a dose- and time-dependent neutrophil accumulation, which was inhibited by dexamethasone, pentoxifylline or thalidomide, but not by selective inhibitors of nitric oxide (nitro-L-arginine), platelet-activating factor (BN50730 or UK74505), prostaglandins (indomethacin), histamine (meclisine) or leukotriene B4 (MK 886 and CP105,696). Anti-TNF-alpha antiserum, but not anti-interleukin-1beta or anti-CINC-1 (cytokine-induced neutrophil chemoattractant 1) antisera, impaired ovalbumin-induced neutrophil accumulation. High amounts of TNF-alpha were detected in the exudates, which was inhibited by dexamethasone, pentoxifylline and thalidomide. These results suggest a specific role for TNF-alpha in this model, and the ability of pentoxifylline and thalidomide to inhibit both neutrophil influx and TNF-alpha release may have therapeutic implications in arthritis.

IL-10 and IL-4 regulate type-I and type-II IL-1 receptors expression on IL-1 beta-activated mouse primary astrocytes

When activated by its ligand, the interleukin receptor type I (IL-1RI) transduces signals in cooperation with the IL-1 receptor accessory protein (IL-1RacP). In contrast, IL-1RII functions as a decoy receptor without participating in IL-1 signalling. Brain astrocytes are cellular targets of IL-1 and play a pivotal role in brain responses to inflammation. The regulation of IL-1 receptors on astrocytes by anti-inflammatory cytokines such as IL-4 and IL-10 has not been studied, despite its importance for understanding the way these cells respond to IL-1. Using RT-PCR, we first showed that the expression of IL-1RI and IL-1RII, but not IL-1RacP, mRNAs are up-regulated by IL-1 beta in a time-dependent manner. Using a radioligand binding technique, we then showed that astrocytes display an equivalent number of IL-1RI and IL-1RII. IL-1 beta decreases the number of IL-1RI binding sites, whereas it increases those of IL-1RII. IL-4 and IL-10 both up-regulate IL-1RII IL-1 beta-induced, but only IL-4 does so for IL-1RI. At the protein level, IL-4 and IL-10 dramatically reverse the ability of IL-1 beta to inhibit expression of IL-1RI but neither affects the ability of IL-1 beta to enhance the number of IL-1RII. Collectively, these results establish the existence of receptor cross-talk between pro- and anti-inflammatory cytokines on a critical type of cell that regulates inflammatory events in the brain.

Surface membrane antigen alteration on blood basophils in patients with Hymenoptera venom allergy under immunotherapy

BACKGROUND

Venom immunotherapy (VIT) provides widespread protection against systemic anaphylactic reactions after a sting of the respective insect. This effect is attributed to a shift from T(H)2 to T(H)1. However, because basophils also produce and release cytokines, such as IL-4 and IL-13, they may be part of the cytokine network. The cytokines may regulate basophilic granulocytes, as suggested by the presence of cytokine receptors IL-2Ralpha, GM-CSFRalpha, IL-1RII, IL-3R, IL-4R, IL-5R, and IL-6R on basophils from nonallergic donors.

OBJECTIVE

The purpose of this study was to demonstrate that human basophils from subjects allergic to wasp venom undergoing VIT are regulated by cytokines, as shown by the alteration of the expression of cytokine receptors (and other markers).

METHODS

The expression of the surface interleukin receptors and activation antigens on basophils from 19 nonallergic subjects and 48 patients with wasp venom allergy was investigated before, immediately after, and 1 week after VIT (20 patients only).

RESULTS

Basophilic granulocytes in allergic subjects, compared with those in healthy persons, showed elevated expression of CD32 (FcgammaRII), CD122 (IL-2Rbeta), CD124 (IL-4Ralpha), CD130 (IL-6 and 11Rbeta), CD154 (CD40L), and HLA-DR. Activation of basophils clearly increased during VIT indicated by increased expression of CD32, CD33, CD35 (CR1), CD63, CD116 (GM-CSFRalpha), CD122, CD124, CD130, and CD154. HLA-DR expression also tended to increase. The expression of IL-5R (CD125) decreased. A significant decrease of the basophilic surface antigens CD11c, CD32, CD35, CD63, CD116, CD122, CD124, CD130, and CD132 (interleukin receptor gamma) was detected 1 week after the end of rush VIT.

CONCLUSION

The rise in CD63 during VIT indicates a partial basophil degranulation with release of stored protein mediators, including IL-4. IL-4 may cause a transient upregulation of different surface antigens in an autocrine manner. Thereafter, cytokines released by T cells, which as a result of VIT have changed from a T(H)2 type to a more T(H)1 type, downregulate the activation of the basophilic granulocytes.

Down-regulation of the hepatic cytochrome P450 by an acute inflammatory reaction: implication of mediators in human and animal serum and in the liver

1. Infection and inflammation trigger a cascade of mediators that eventually will down-regulate the hepatic cytochrome P450 (P450). The present study aimed to characterize the mediators contained in the serum of rabbits with an acute inflammatory reaction (AIR) induced by the s.c. injection of turpentine (5 ml), and in the serum of humans with an acute upper respiratory tract viral infection. 2. Hepatocytes from control (H(CONT)) rabbits and rabbits with an AIR (H(INFLA)) were isolated and cultured. Compared with H(CONT) in H(INFLA) the production of theophylline metabolites, 3-methylxanthine (3MX), 1-methyluric acid (1MU), and 1,3-dimethyluric acid (1,3DMU) was reduced as was the amount of total P450, while lipid peroxidation was increased. Incubation of H(INFLA) with serum of rabbits with an AIR (RS(INFLA)) for 4 h further reduced the formation of the metabolites of theophylline as well as the amount of P450, and enhanced the lipid peroxidation. RS(INFLA) obtained 6, 12 and 24 h after the injection of turpentine showed the same ability to down-regulate hepatic P450 as the serum obtained at 48 h. 3. The efficacy (Emax) of RS(INFLA) to inhibit the formation of theophylline metabolites differed, i.e. 1,3DMU > 1MU > 3MX, and the potency of serum mediators (IC50) was similar for 3MX and 1MU, but lower for 1,3DMU. 4. Incubation of serum of human volunteers (HS(INFLA)) with a viral infection with H(CONT) or H(INFLA) reduced the production of theophylline metabolites, as well as the amount of P450, and increased the lipid peroxidation. HS(INFLA) depressed 1,3DMU more efficiently than 3MX and 1MU. HS(INFLA) reduced 3MX with greater efficacy than did RS(INFLA). Potency was very variable but not different from rabbits. 5. It is concluded that the serum of rabbits with an AIR or of humans with a viral infection contain several mediators that inhibit noncompetitively various isoenzymes of the hepatic P450. The decrease in P450 induced by HS(INFLA) or RS(INFLA) is closely associated with the increase in lipid peroxidation (r2= 0.8870) suggesting that lipid peroxidation could directly or indirectly be involved in the P450 down-regulation.

Type I and type II interferons upregulate functional type I interleukin-1 receptor in a human fibroblast cell line TIG-1

The regulation of type I interleukin-1 receptor (IL-1R) expression by type I, interferon (IFN)-alpha A/D, and type II IFN, IFN-gamma, in a human fibroblast cell line TIG-1 was investigated. After 2 h stimulation with human IFN-alpha A/D or IFN-gamma, the levels of type I IL-1R mRNA increased. We previously reported that IL-1 upregulates transcription and cell surface molecules of type I IL-1R in TIG-1 cells through induction of prostaglandin (PG) E2 and cAMP accumulation. However, indomethacin was unable to inhibit the effect of IFNs, indicating that IFNs augment IL-1R expression through a pathway distinct from that of IL-1. The augmentation was also observed in other fibroblast cell lines. Nuclear run-on assays and studies of the stability of mRNA suggested that the increase in IL-1R mRNA was a result of the enhanced transcription of IL-1R gene. Binding studies using 125I-IL-1 alpha revealed that the number of cell surface IL-1R increased with no change in binding affinity by treatment with these IFNs. Pretreatment of the cells with IFNs enhanced IL-1-induced IL-6 production, indicating that IFNs upregulate functional IL-1R. IL-1 and IFNs are produced by the same cell types, as well as by the adjacent different cell types, and are concomitantly present in lesions of immune and inflammatory reactions. These results therefore suggest that IFNs exhibit synergistic effects with IL-1 through upregulation of IL-1R. Augmented production of IL-6 may also contribute to the reactions.

Interleukin-12/T cell stimulating factor, a cytokine with multiple effects on T helper type 1 (Th1) but not on Th2 cells

At least two subsets of CD4+ T helper cell lymphocytes termed Th1 and Th2 exist in the mouse and probably in humans. They are characterized by the secretion of different lymphokines and by their functional behavior. Dysregulated expansion of one or the other subset may be one reason for the development of certain diseases. Thus, it is of importance to define the signals involved in the differentiation and activation of the two Th cell subsets. It is known and has been confirmed in this report that the cytokine interleukin (IL)-1 acts on Th2 cells but not on Th1 cells. We now report that a previously identified cytokine which was provisionally termed T cell stimulating factor is identical with IL-12 and exhibits a reciprocal behaviour to IL-1. IL-12 has several effects on Th1 cells. It can induce the proliferation of certain Th1 cells in combination with IL-2. Synthesis of interferon (IFN)-gamma by Th1 cells can be triggered by IL-2 plus IL-12. In contrast to the IFN-gamma production observed after T cell receptor (TcR) CD3 stimulation of Th1 cells with lectin Concanavalin A the IFN-gamma production induced by IL-12 + IL-2 is insensitive to the immunosuppressive drug cyclosporin A. Furthermore, IL-12 enhances the TcR/CD3-induced synthesis of IFN-gamma of several Th1 clones. Finally, IL-12 (+IL-2) induces homotypic cell aggregation of Th1 clones. This type of cell aggregation depends on the participation of LFA-1 and ICAM-1 molecules. In all activation systems with Th1 cells no effect of IL-1 was demonstrable. In contrast, only IL-1 but not IL-12 served as a co-stimulatory signal for several Th2 cell lines activated via the TcR/CD3 complex.

Interleukin-1 type II receptor: a decoy target for IL-1 that is regulated by IL-4

Interleukin-1 (IL-1) interacts with cells through two types of binding molecules, IL-1 type I receptor (IL-1R I) and IL-1R II. The function of IL-1R II is unknown. In studies using monoclonal antibodies, IL-1 prolonged the in vitro survival of polymorphonuclear cells (PMN) through IL-1R I, and IL-4 antagonized the action of IL-1 by inducing expression and release of IL-1R II. Dexamethasone also induced expression and release of the IL-1R II in PMN. These results, together with the effect of antibodies to IL-1R on IL-1-induced production of cytokines in monocytes, indicate that IL-1 acts on myelomonocytic cells through IL-1R I and that IL-1R II inhibits IL-1 activity by acting as a decoy target for IL-1. The existence of multiple pathways of regulation emphasizes the need for tight control of IL-1 action.

Modulation of macrophage function by transforming growth factor beta, interleukin-4, and interleukin-10

The findings reviewed above leave no doubt as to the complexity of actions of TGF-beta, IL-4, and IL-10 on monocytes/macrophages. Along with MDF, whose actions were recently reviewed elsewhere, TGF-beta, IL-4, and IL-10 are the only presently known, purified cytokines that have been shown to have strong macrophage-deactivating effects. However, none of them can be categorized as purely macrophage deactivating since they also exert macrophage-activating effects. In vitro, their effects, both in terms of extent and direction (activating vs. deactivating), are strongly influenced by the stimulation conditions (e.g., triggering signal, cytokine concentration, timing of cytokine addition), the species (mouse vs. human), the source (blood vs. peritoneal, alveolar, colostral) and the state of differentiation/activation of the macrophage (e.g., resting vs. inflammatory). In addition, TGF-beta, as well as IL-4 and IL-10, up- and/or downregulates the function of several cell types other than macrophages, which further hampers our ability to predict, on the basis of in vitro experiments with macrophages, possible effects during an immune response in vivo. Despite this complexity, the highly reductive approach of in vitro studies has revealed important differences in the ability of TGF-beta, IL-4, and IL-10 to modulate the phenotype of monocytes/macrophages. The disparities have been most striking with regard to the secretory function of monocytes/macrophages (see Table 2). First, TGF-beta, IL-4, and IL-10 have a different spectrum of activity. Thus, TGF-beta, but not IL-4 or IL-10, can induce resting human monocytes to produce TNF, IL-1, and IL-6. Second, they affect monokine and RNI and ROI production to a different extent. For example, IL-10 is an approximately 25-fold more potent suppressor of LPS-induced TNF production by mouse macrophages than is TGF-beta. Third, they differ in their ability to overcome additional activating stimuli, so that in the presence of LPS, IL-4, but not TGF-beta or IL-10 suppresses IFN gamma-induced RNI release. Fourth, their macrophage-deactivating effects require different stimulation conditions. Thus, IL-4, but not TGF-beta, interferes with RNI release strongly only after preincubation of the macrophages. Finally, these agents deactivate macrophages by distinct mechanisms. For example, IL-10 causes massive downregulation of TNF mRNA, whereas TGF-beta suppresses TNF release on a translational level. It will be a challenge to define clinical applications for these potent macrophage modulators on the basis of their different spectrum of activities. For TGF-beta and IL-4 such studies have already been initiated.

Selective differentiation of CD4+ T helper cell subsets

During the past year significant advances have been made in our understanding of the factors contributing to the differentiation of CD4 T helper cell subsets. These have been driven, in part, by the realization that signals (cytokines) from the innate immune response are critical in T cell subset differentiation. In addition, several studies have also elucidated how the antigen-presenting cell, the antigenic epitope and the antigen concentration may contribute to the selective development of a particular T helper cell subset.

Differential regulation of tumour necrosis factor receptors (TNF-R) by IL-4; upregulation of P55 and P75 TNF-R on synovial joint mononuclear cells

Interleukin 4 (IL-4) has previously been shown to downregulate the production of proinflammatory cytokines such as TNF-alpha, and hence has been considered to be a potential anti-inflammatory agent. In this study we have investigated the effects of IL-4 on the expression of both p55 and p75 TNF receptors (TNF-R) by flow cytometry and radioligand binding analyses and demonstrate that IL-4 downregulates both p55 and p75 TNF-R on HeLa and Jijoye cell lines in a dose dependent manner. IL-4 reduced the number of p55 TNF-R on HeLa cells from 6400 (Kd 5.1 nM) to 3900 (Kd 3.7 nM), and p75 TNF-R on Jijoye cells from 4800 (Kd 1.6 nM) to 3250 (Kd 1.5 nM). However, different effects were observed on peripheral blood mononuclear cells (PBMC). IL-4 inhibited the increase in p55 and p75 TNF-R on PBMC following adherence, whereas IL-4 upregulated p75 TNF-R expressed on PHA induced T cell blasts. To assess further the possible anti-inflammatory properties of IL-4, we studied its effects on synovial joint mononuclear cell cultures from 15 patients with inflammatory synovitis. In contrast to the differential effects of IL-4 on monocytes and T cells, IL-4 upregulated both p55 (P < 0.05) and p75 TNF-R (P < 0.005) on synovial joint cells in culture. IL-4 treatment caused a small decrease in levels of bioactive TNF-alpha in RA synovial culture supernatants, together with an increase in soluble p75 TNF-R levels although differences were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of the promoter region of human interleukin 1 type I receptor gene: multiple initiation sites, high G+C content, and constitutive expression

To better understand the role of interleukin 1 (IL-1) and its receptor in disease, we have isolated a genomic clone of the human IL-1 type I receptor and have identified the promoter region. There are multiple transcriptional initiation sites as demonstrated by primer extension. DNA sequence analysis shows that the promoter region contains neither a TATA nor a CAAT box; however, the 5' upstream regulatory elements contain two AP-1-like binding sites. The internal regulatory sequences found immediately downstream to the 5' transcriptional start site contain four Sp1 binding domains and have a high G+C content of 75%. This portion of the 5' untranslated region of the mRNA can form stable secondary structure as predicted by computer modeling. Base pairs -4 to + 10 share striking resemblance to an initiator sequence that directs basal expression of certain TATA-less genes-e.g., terminal deoxynucleotidyltransferase in lymphocytes. The IL-1 receptor promoter directs basal expression of chloramphenicol acetyltransferase in transiently transfected cells. Overall, the promoter of the IL-1 type I receptor gene resembles that of constitutively expressed genes that have housekeeping- and/or growth-related functions. The constitutive nature of the promoter may account for this gene being expressed at low levels in diverse cell types. Our finding sheds more understanding into the mechanisms governing the regulation of the IL-1 receptor in health and disease.