Treatment of systemic lupus erythematosus: new therapeutic options

Systemic lupus erythematosus (SLE) is a systemic autoimmune inflammatory disease of unknown cause, with heterogeneity in its clinical presentation, as well as variability in its clinical course and prognosis. The current goal of treatment is to achieve disease remission or a state of low activity, and thereby improve the patient's quality of life. Biological therapy in lupus, unlike other entities, although it has not been fully established, in recent years it has burst onto the scene with important therapeutic novelties. This review aims to update the therapeutic tools for the treatment of SLE focusing on the new molecules that have achieved the objectives of their clinical trials.

Ocular involvement in adult and paediatric patients with monogenic autoinflammatory diseases: a Spanish multicentre retrospective study

OBJECTIVES

Ophthalmologic involvement in monogenic autoinflammatory diseases has been explored mainly in paediatric patients. The aim of this study is to characterise ophthalmologic manifestations, therapeutic management and visual outcomes in a Spanish (UVESAI) cohort of adult/paediatric patients with monogenic autoinflammatory diseases.

METHODS

Multicentre and retrospective study of patients with monogenic autoinflammatory diseases and ocular involvement. Eye manifestations, structural complications, treatments used and visual outcomes were analysed, and compared with previous studies.

RESULTS

Forty-six patients (44/2 adults/children; 21/25 adult/paediatric-onset) with monogenic autoinflammatory diseases [cryopyrin associated periodic syndromes (n=13/28.3%), mainly Muckle-Wells syndrome (MWS) (n=11/24%); familial Mediterranean fever (FMF) (n=12/26%); TNF receptor-associated periodic syndrome (TRAPS); (n=9/20%); Blau syndrome (n=8/17%); hyperimmunoglobulin D syndrome (HIDS) (n=2/4.3%), deficiency of adenosine deaminase-2 and NLRC4-Autoinflammatory disease] (one each) were included. Conjunctivitis (n=26/56.5%) and uveitis (n=23/50%) were the most frequent ocular manifestations. Twelve (26.1%) patients developed structural complications, being cataracts (n=11/24%) and posterior synechiae (n=10/22%) the most frequent. Conjunctivitis predominated in TRAPS, FMF, MWS and HIDS (mainly in adults), and uveitis, in Blau syndrome. Seven (8%) eyes (all with uveitis) presented with impaired visual acuity. Local and systemic treatment led to good visual outcomes in most patients. Compared with previous studies mainly including paediatric patients, less severe ocular involvement was observed in our adult/paediatric cohort.

CONCLUSIONS

Conjunctivitis was the most common ocular manifestation in our TRAPS, FMF, MWS and HIDS patients, and uveitis predominated in Blau syndrome. Severe eye complications and poor visual prognosis were associated with uveitis. Adults with monogenic autoinflammatory diseases seem to exhibit a less severe ophthalmologic presentation than paediatric patients.

Coexistence of immune-mediated diseases in sarcoidosis. Frequency and clinical significance in 1737 patients

OBJECTIVE

To analyze whether immune-mediated diseases (IMDs) occurs in sarcoidosis more commonly than expected in the general population, and how concomitant IMDs influence the clinical presentation of the disease.

METHODS

We searched for coexisting IMDs in patients included in the SARCOGEAS-cohort, a multicenter nationwide database of consecutive patients diagnosed according to the ATS/ESC/WASOG criteria. Comparisons were made considering the presence or absence of IMD clustering, and odds ratios (OR) and their 95% confidence intervals (CI) were calculated as the ratio of observed cases of every IMD in the sarcoidosis cohort to the observed cases in the general population.

RESULTS

Among 1737 patients with sarcoidosis, 283 (16%) patients presented at least one associated IMD. These patients were more commonly female (OR: 1.98, 95% CI: 1.49-2.62) and were diagnosed with sarcoidosis at an older age (49.6 vs. 47.5years, P<0.05). The frequency of IMDs in patients with sarcoidosis was nearly 2-fold higher than the frequency observed in the general population (OR: 1.64, 95% CI: 1.44-1.86). Significant associations were identified in 17 individual IMDs. In comparison with the general population, the IMDs with the strongest strength of association with sarcoidosis (OR>5) were common variable immunodeficiency (CVID) (OR: 431.8), familial Mediterranean fever (OR 33.9), primary biliary cholangitis (OR: 16.57), haemolytic anemia (OR: 12.17), autoimmune hepatitis (OR: 9.01), antiphospholipid syndrome (OR: 8.70), immune thrombocytopenia (OR: 8.43), Sjögren syndrome (OR: 6.98), systemic sclerosis (OR: 5.71), ankylosing spondylitis (OR: 5.49), IgA deficiency (OR: 5.07) and psoriatic arthritis (OR: 5.06). Sex-adjusted ORs were considerably higher than crude ORs for eosinophilic digestive disease in women, and for immune thrombocytopenia, systemic sclerosis and autoimmune hepatitis in men.

CONCLUSION

We found coexisting IMDs in 1 out of 6 patients with sarcoidosis. The strongest associations were found for immunodeficiencies and some systemic, rheumatic, hepatic and hematological autoimmune diseases.

Transition-metal adatoms on 2D-GaAs: a route to chiral magnetic 2D materials by design

Using relativistic density-functional calculations, we examine the magneto-crystalline anisotropy and exchange properties of transition-metal atoms adsorbed on 2D-GaAs. We show that single Mn and Mo atom (Co and Os) strongly bind on 2D-GaAs, and induce local out-of-plane (in-plane) magnetic anisotropy. When a pair of TM atoms is adsorbed on 2D-GaAs in a close range from each other, magnetisation properties change (become tunable) with respect to concentrations and ordering of the adatoms. In all cases, we reveal presence of strong Dzyaloshinskii-Moriya interaction. These results indicate novel pathways towards two-dimensional chiral magnetic materials by design, tailored for desired applications in magneto-electronics.

Two-dimensional hydrogenated buckled gallium arsenide: an ab initio study

First-principles calculations have been carried out to investigate the stability, structural and electronic properties of two-dimensional (2D) hydrogenated GaAs with three possible geometries: chair, zigzag-line and boat configurations. The effect of van der Waals interactions on 2D H-GaAs systems has also been studied. These configurations were found to be energetic and dynamic stable, as well as having a semiconducting character. Although 2D GaAs adsorbed with H tends to form a zigzag-line configuration, the energy differences between chair, zigzag-line and boat are very small which implies the metastability of the system. Chair and boat configurations display a [Formula: see text]-[Formula: see text] direct bandgap nature, while pristine 2D-GaAs and zigzag-line are indirect semiconductors. The bandgap sizes of all configurations are also hydrogen dependent, and wider than that of pristine 2D-GaAs with both PBE and HSE functionals. Even though DFT-vdW interactions increase the adsorption energies and reduce the equilibrium distances of H-GaAs systems, it presents, qualitatively, the same physical results on the stability and electronic properties of our studied systems with PBE functional. According to our results, 2D buckled gallium arsenide is a good candidate to be synthesized by hydrogen surface passivation as its group III-V partners 2D buckled gallium nitride and boron nitride. The hydrogenation of 2D-GaAs tunes the bandgap of pristine 2D-GaAs, which makes it a potential candidate for optoelectronic applications in the blue and violet ranges of the visible electromagnetic spectrum.

Tunable 2D-gallium arsenide and graphene bandgaps in a graphene/GaAs heterostructure: an ab initio study

The bandgap behavior of 2D-GaAs and graphene have been investigated with van der Waals heterostructured into a yet unexplored graphene/GaAs bilayer, under both uniaxial stress along c axis and different planar strain distributions. The 2D-GaAs bandgap nature changes from [Formula: see text]-K indirect in isolated monolayer to [Formula: see text]-[Formula: see text] direct in graphene/GaAs bilayer. In the latter, graphene exhibits a bandgap of 5 meV. The uniaxial stress strongly affects the graphene electronic bandgap, while symmetric in-plane strain does not open the bandgap in graphene. Nevertheless, it induces remarkable changes on the GaAs bandgap-width around the Fermi level. However, when applying asymmetric in-plane strain to graphene/GaAs, the graphene sublattice symmetry is broken, and the graphene bandgap is open at the Fermi level to a maximum width of 814 meV. This value is much higher than that reported for just graphene under asymmetric strain. The [Formula: see text]-[Formula: see text] direct bandgap of GaAs remains unchanged in graphene/GaAs under different types of applied strain. The analyses of phonon dispersion and the elastic constants yield the dynamical and mechanical stability of the graphene/GaAs system, respectively. The calculated mechanical properties for bilayer heterostructure are better than those of their constituent monolayers. This finding, together with the tunable graphene bandgap not only by the strength but also by the direction of the strain, enhance the potential for strain engineering of ultrathin group-III-V electronic devices hybridized by graphene.

Vibrational properties of germanane and fluorinated germanene in the chair, boat, and zigzag-line configurations

The electronic and vibrational properties of germanane and fluorinated germanene are studied within density functional theory (DFT) and density functional perturbation theory frameworks. Different structural configurations of germanane and fluorinated germanene are investigated. The energy difference between the different configurations are consistently smaller than the energy of thermal fluctuations for all the analyzed DFT functionals LDA, GGA, and hybrid functionals, which implies that, in principle, it is possible to find these different configurations in different regions of the sample as minority phases or local defects. We calculate the Raman and infrared spectra for these configurations by using ab initio calculations and compare it with available experimental spectra for germanane. Our results show the presence of minority phases compatible with the configurations analyzed in this work. As these low energy configurations are metastable the present work shows that the synthesis of these energy competing phases is feasible by selectively changing the synthesis conditions, which is an opportunity to expand in this way the availability of new two-dimensional compounds.

Extra-pulmonary tuberculosis: differential aspects and role of 16S-rRNA in urine

BACKGROUND

Early diagnosis of extra-pulmonary tuberculosis (EPTB) is important for successful treatment.

METHODS

All cases of EPTB diagnosed at Ramon y Cajal Hospital, Madrid, Spain, from 1997 to 2008 were analysed and compared with pulmonary tuberculosis (PTB) patients to identify differential parameters that could serve to predict the presence of EPTB at initial presentation. Different microbiological techniques were analysed, including amplification of 16S-rRNA in urine.

RESULTS

During the study period, 814 cases of TB were diagnosed at our centre; 330 (40.5%) were EPTB. Concomitant PTB was detected in 45% of EPTB cases. The main clinical forms of EPTB were lymphadenitis (86, 26%), miliary TB (60, 18%), and multifocal TB (43, 13%). Variables independently associated with EPTB were human immunodeficiency virus (HIV) infection (OR 3.6, 95%CI 2.4-5.4), older age (>60 years) (OR 3.7, 95%CI 2.5-5.6) and mortality (OR 2.9, 95%CI 1.3-6.3). 16S-rRNA in urine was performed in 82 EPTB patients (25%), among whom a positive result was obtained in 70%; in the PTB group, a positive result was found in 5 of 28 patients (18%) (P <0.001).

CONCLUSIONS

HIV infection and older age appear to be the main risk factors associated with EPTB. In this study, mortality was significantly higher in patients with EPTB. A positive 16S-rRNA test result in urine is a useful marker of EPTB.

Extra-pulmonary tuberculosis: a biomarker analysis

INTRODUCTION

Studies on biomarkers in tuberculosis are focused on pulmonary forms of this disease (PTB), and only limited information is currently available on biomarkers of extra-pulmonary tuberculosis (EPTB).

METHODS

Serum samples from 24 patients with PTB, 29 patients with EPTB and 27 healthy controls were obtained, and the levels of interferon-gamma, chemokine ligand 9, mannose-binding lectin (MBL), tumor marker Ca-125 and adenosine deaminase were determined.

RESULTS

The circulating levels of all tested biomarkers in the serum were significantly higher in PTB and EPTB patients than in controls. However, there were no significant differences in the levels of the biomarkers between patients with PTB and EPTB, with the exception of serum levels of MBL which were significantly higher in patients with EPTB than in patients with PTB (p = 0.01). In patients with EPTB, no significant differences were observed in biomarker levels among patients with or without concomitant PTB involvement. Based on MBL serum levels, ROC curve analysis showed an AUC of 0.85 for EPTB versus non-EPTB. The optimal cut-off value of MBL serum levels for EPTB versus non-EPTB was 1,000 μg/ml, with a sensitivity and specificity of 79.3 and 78.0 %, respectively.

CONCLUSIONS

Biomarkers usually present as acute phase reactants and do not enable pulmonary forms to be differentiated from more serious or extra-pulmonary forms. MBL may be an exception.

[Perceived satisfaction and usefulness of suicide prevention information for patients and relatives]

OBJECTIVE

To assess the satisfaction of persons with suicidal behaviour and their relatives using patient information material included in the Clinical Practice Guidelines on Prevention and Treatment of Suicidal Behaviour.

METHOD

The sample was made up of 57 patients with suicidal ideation or behaviour, and 52 relatives. The participants were recruited through a suicide prevention programme (Programa de intervención intensiva en conducta suicida [PII] - Suicidal Behaviour Intensive Intervention Programme) and a family association (Federación de Asociaciones de Familiares y Personas con enfermedad mental de Galicia [FEAFES] - Galician Federation of Associations of Relatives and Persons with mental diseases). An ad-hoc questionnaire was designed to ascertain the degree of perceived satisfaction and usefulness of using the information included in the guidelines.

RESULTS

The descriptive data of the sample is presented, along with an exploratory factorial analysis of the questionnaire that yielded two dimensions, i.e., format and usefulness. Patients scored significantly lower than the relatives in two dimensions; nevertheless, no significant differences were found between the two groups in the level of general satisfaction. The socio-demographic variables did not influence the results. Similarly, no differences were observed between patients with and without history of suicidal behaviour. Participants stressed that Primary Care was the setting best suited for dissemination of this type of information.

CONCLUSIONS

In general, both patients and relatives displayed a high level of satisfaction with the patient information material assessed. Furnishing information of this type to patients with suicidal ideation and/or behaviour could act as a preventive-educational tool.

Triamcinolone acetonide mouth rinses for treatment of erosive oral lichen planus: efficacy and risk of fungal over-infection

OBJECTIVES

To assess the efficacy of triamcinolone acetonide mouthrinse for treatment of erosive oral lichen planus (OLP), and to evaluate the risk of fungal over-infection.

PATIENTS AND METHODS

Clinical records of all cases of erosive and erosive-ulcerative OLP treated in our Oral Medicine Service over the period 1993-2003 were reviewed. All patients had been treated with mouthrinses containing triamcinolone acetonide at 0.3% (T1) or 0.5% (T2). Clinical outcome for each patient was classified at 1, 3 and 6 months after start of treatment as total remission (TR), partial remission (PR) or no remission (NR). Fungal over-infection was also recorded.

RESULTS

A total of 35 cases were included in the study. Clinical outcomes considering both treatment groups together (T1 + T2) were as follows: at month 1, 28.6% TR, 62.9% PR, 8.6% NR; at month 3, 57.1% TR, 37.1% PR, 5.7% NR; and at month 6, 80.0% TR, 17.1% PR, 2.9% NR. In four patients (11.4%) fungal over-infection was noted during the study period.

CONCLUSION

Triamcinolone acetonide mouthrinse is an appropriate treatment for erosive OLP, in view of the high efficacy and low risk of fungal over-infection.

Outbreak of Streptococcus equi subsp. zooepidemicus infections on the island of Gran Canaria associated with the consumption of inadequately pasteurized cheese

Streptococcus equi subsp. zooepidemicus infections are infrequent in humans. A clinical and epidemiological study of a milk-borne outbreak caused by this organism is described. Fifteen patients (5 females, 10 males) with a median age of 70 years (range 47-86) were infected. Twelve (80%) had underlying diseases. Infection with S. equi subsp. zooepidemicus presented as primary bacteremia in six cases, as bacteremia associated with aortic aneurism in four cases, as septic arthritis in two cases, as pneumonia in two cases, and as meningitis in one case. Five (33.3%) patients died. A case-control study proved that consumption of inadequately pasteurized cheese of a specific brand was associated with S. equi subsp. zooepidemicus disease (OR=4.5; 95% CI 1.57-19.27; p<0.001). This outbreak serves as a reminder that S. equi subsp. zooepidemicus causes serious infections that are usually zoonoses. Identification of beta-hemolytic streptococci to the species level to detect contaminated foods of animal origin is important for preventing new food-borne outbreaks. For a precise characterization of the isolates, the application of molecular markers is recommended.

[Endovascular treatment of carotid disease. The state of the art, technical aspects and occupational training]

AIMS

The aim of this study was to carry out a review of the state of the art in the endovascular treatment of carotid disease, taking into account the findings currently available, its indications, the technical aspects linked to the intervention as well as those related to the occupational training of the specialists involved in performing the technique.

DEVELOPMENT

Surgical treatment of carotid artery disease can be of benefit to symptomatic patients with stenoses above 70% and to subgroups of patients with symptomatic stenoses between 50-69%. The benefit of carotid endarterectomy in asymptomatic patients is the object of a great deal of controversy that is concerned with the reduction in risk that is obtained and also the large number of patients to be treated in order to prevent the occurrence of ischaemic events. The endovascular treatment of carotid disease comes to the fore, then, as an alternative to surgical treatment. At the present time, a number of randomised multicentre studies are being conducted that will allow the two techniques to be compared in homogeneous groups of patients. Preliminary data nevertheless seem to suggest that this technique offers a number of benefits, especially in groups of subjects with a high surgical risk, and thus they could allow the indications for revascularisation to be extended. We analyse the technical and medical aspects linked to this procedure, the findings from studies carried out to date, its indications and the occupational training of the specialists involved in performing the technique.

CONCLUSIONS

The endovascular treatment of carotid disease constitutes an alternative to surgical treatment in specifically selected patients. The potential increase in its indications is conditioned by the results from the multicentre studies currently being carried out.

[Compression of the internal carotid artery due to elongated styloid process]

INTRODUCTION

Elongation of the styloid process has been reported as a source of pain in the head and neck region. However, transient ischemic attack (TIA) due to mechanical compression of the internal carotid artery (ICA) by an elongated styloid process has never been mentioned in the literature.

CASE REPORT

Male aged 36 years, with a ten-year history of dull intermittent pain in the left side of the neck that worsened on turning the head, suffered a TIA in the silvian territory, ten days after a minor neck trauma. The eco-Doppler exploration demonstrated a compression of the ICA after rotation of the head. The arteriography revealed an stenosis of the cervical ICA by an external compression. The length of the elongated process in the orthopantomogram and the computed tomography was 35 mm. Angiotomography showed a closed relationship between the tip of the left elongated process and the stenosis of the ICA. Surgical styloidectomy was performed via an extraoral approach under general anaesthesia. The excised specimen measured 30 mm long. All symptoms were relieved with no recurrence during a three-year follow up period.

CONCLUSION

TIA should be taken into account in the clinical feature associated to an elongated styloid process. Angiotomography is very reliable to define the anatomic relationship between the styloid process and the ICA. The treatment of choice is surgical shortening trough an external approach which provides an adequate control of the carotid artery.

The identification of phosphatidylinositol 3,5-bisphosphate in T-lymphocytes and its regulation by interleukin-2

In recent times 3-phosphoinositides have emerged as important regulators of cell metabolism, survival, and proliferation. During the last year, the phospholipid phosphatidylinositol 3, 5-bisphosphate (PtdIns3,5P2) was identified in yeast, fibroblasts, SV40-transformed kidney (COS-7) cells, and platelets. The discovery of this novel phospholipid has increased the complexity of the metabolism relating to the generation of biologically active inositol-containing lipids. We describe here the identification of PtdIns3,5P2 in the CTLL-2 mouse T-lymphocyte cell line using two in vivo radiolabeling protocols. Treatment of the cells with UV radiation led to an increase in the cellular content of PtdIns3,5P2. In contrast, preincubation of the cells with wortmannin or treatment with hypertonic medium (high concentration sorbitol) led to the opposite effect. Herein we demonstrate that interleukin-2 (IL-2), the growth factor required for CTLL-2 cell proliferation, was able to increase the level of PtdIns3,5P2 with similar kinetics to that of the formation of phosphatidylinositol 3,4-bisphosphate (PtdIns3, 4P2). An increase in this novel 3-phosphorylated lipid in response to IL-2 seems to be a general property of this cytokine because a similar result was obtained when the pre-B cell line BaF/3 expressing the high affinity IL-2 receptor was used. Using a constitutively active regulatory subunit of type I phosphatidylinositol 3-kinase and cells expressing a deletion of the serine-rich domain of the IL-2 receptor beta chain, which is required for IL-2-stimulated type I phosphatidylinositol 3-kinase activation, we demonstrate that IL-2-induced generation of PtdIns3, 5P2 is related to the activation of this enzyme. The results show for the first time the identification of PtdIns3,5P2 in both T- and B-lymphocytes and indicate its positive regulation by the mitogen IL-2.

Intermediate affinity interleukin-2 receptor mediates survival via a phosphatidylinositol 3-kinase-dependent pathway

Peripheral blood T lymphocytes require two signals to enter and progress along the cell cycle from their natural quiescent state. The first activation signal is provided by the stimulation through the T cell receptor, which induces the synthesis of cyclins and the expression of the high affinity interleukin-2 receptor. The second signal, required to enter the S phase, is generated upon binding of interleukin-2 to the high affinity alphabetagamma interleukin-2 receptor. However, resting T cells already express intermediate affinity betagamma interleukin-2 receptors. As shown here, T cell stimulation through intermediate affinity receptors is capable of inducing cell rescue from the apoptosis suffered in the absence of stimulation. Characterization of the signaling pathways utilized by betagamma interleukin-2 receptors in resting T cells, indicated that pp56(lck), but not Jak1 or Jak3, is activated upon receptor triggering. Compelling evidence is presented indicating that phosphatidylinositol 3-kinase associates with the intermediate affinity interleukin-2 receptor and is activated upon interleukin-2 addition. Bcl-xL gene was also found to be induced upon betagamma interleukin-2 receptor stimulation. Finally, pharmacological inhibition of phosphatidylinositol 3-kinase blocked both interleukin-2-mediated bcl-xL induction and cell survival. We conclude that betagamma interleukin-2 receptor mediates T-cell survival via a phosphatidylinositol 3-kinase-dependent pathway, possibly involving pp56(lck) and bcl-xL as upstream and downstream effectors, respectively.

Polyethylene glycol-modified IL-2 abrogates superantigen-induced anergy without affecting peripheral clonal deletion in vivo

As compared with the native molecule, recombinant human interleukin-2 that is modified by covalently attached polyethylene glycol residues (IL-2-PEG) exhibits a markedly enhanced half-life in vivo, thus facilitating its biological evaluation. We have characterized the effect of IL-2-PEG on the Staphylococcus aureus enterotoxin B (SEB)-induced tolerance of peripheral SEB-reactive (V beta 8+) T cells. Treatment with sublethal doses of IL-2-PEG does not modulate (inhibit or enhance) the SEB-triggered apoptosis and deletion of V beta 8+ T cells. In contrast, in vivo treatment with IL-2-PEG partially abolishes the SEB-triggered anergy of V beta 8+ T cells, i.e., the failure to proliferate in response to SEB in vitro. To abolish SEB-triggered anergy, IL-2-PEG must act for an extended period in vivo; short term treatment in vivo (2 days) or exposure of anergic T cells to IL-2 in vitro fails to reconstitute proliferative responses. Moreover, the effect of in vivo treatment with IL-2-PEG on lymphokine production by anergic T cells is partial. IL-2-PEG restores IL-4-dependent autocrine proliferation in response to SEB but does not reestablish defective IL-2 production. These data are compatible with the notion that IL-2 is a regulator of postdeletional rather than deletional T cell tolerance.

Differential involvement of Th1 and Th2 cytokines in autoimmune diseases

By virtue of their functional antagonism, Th1 cells or cells producing the same cytokines as Th1 cells may behave as "suppressor cells' with respect to Th2 cells and vice versa. An excessive Th1- or Th2-like response may favor the development of different autoimmune diseases. As can be expected from their physiological role, Th-1 cytokines participate in autoimmune diseases with a preferential delayed type hypersensitivity component, i.e. in those diseases in which cytotoxic T cells attack organ-specific target cells. Autoimmune diseases with a predominant Th1 component include experimental autoimmune encephalitis and insulin-dependent diabetes mellitus. In contrast, Th2-type responses participate in systemic autoimmune diseases with a strong humoral component. Such diseases probably include certain drug-induced states of autoaggression, namely mercury-induced autoimmune disease and chlorpromazine-induced autoimmunity. It is tempting to speculate that therapeutic interventions designed to recover a normal Th1/Th2 balance will provide a useful etiological strategy for the re-establishment of self-tolerance.

Chlorpromazine amplifies macrophage-dependent IL-10 production in vivo

Chlorpromazine (CPZ) has potent immunomodulatory effects in vivo; it induces humoral autoimmunity in up to 50% of patients, inhibits delayed-type hypersensitivity reactions, and suppresses lethal immune hyperactivation in animal models of septic shock. Here, we show that in an in vivo model of acute superantigen-driven immune activation, CPZ independently down-regulates the production of various T cell-derived lymphokines (IL-2, IFN-gamma, IL-4, TNF, and GM-CSF) and up-regulates the secretion of IL-10. Whereas only low, if any, serum IL-10 levels are detectable by ELISA after injection of CPZ, bacterial LPS, or staphylococcal enterotoxin B (SEB) alone, simultaneous administration of CPZ + LPS or CPZ + SEB causes a significant increase in IL-10 production in vivo. CPZ-mediated amplification of the SEB-driven CPZ secretion is accompanied by an enhanced IL-10 mRNA accumulation, as shown by PCR analysis and in situ hybridization. Determination of IL-10 production in mice lacking T cells, B cells, or phagocytes revealed that SEB + CPZ-induced IL-10 was produced by phagocytic cells, but not by lymphocytes, a finding that is in accord with the distribution of splenic cells transcribing the IL-10 gene in response to SEB + CPZ. Moreover, these data indicate that bacterial superantigen can directly stimulate tissue phagocytes, even in the virtual absence of T lymphocytes. The blockade of dopamine type 1 (D1) but not type 2 (D2) receptors abolishes the CPZ effect on IL-10 production. Inhibition of Th1 and Th2 lymphokine production by CPZ is not mediated by dopamine receptors and is independent of IL-10 up-regulation. These findings may explain the mechanism by which CPZ and related drugs enhance humoral autoimmune reactions, block cellular immune responses, and prevent lethal septic shock in vivo.

Chlorpromazine amplifies macrophage-dependent IL-10 production in vivo

Chlorpromazine (CPZ) has potent immunomodulatory effects in vivo; it induces humoral autoimmunity in up to 50% of patients, inhibits delayed-type hypersensitivity reactions, and suppresses lethal immune hyperactivation in animal models of septic shock. Here, we show that in an in vivo model of acute superantigen-driven immune activation, CPZ independently down-regulates the production of various T cell-derived lymphokines (IL-2, IFN-gamma, IL-4, TNF, and GM-CSF) and up-regulates the secretion of IL-10. Whereas only low, if any, serum IL-10 levels are detectable by ELISA after injection of CPZ, bacterial LPS, or staphylococcal enterotoxin B (SEB) alone, simultaneous administration of CPZ + LPS or CPZ + SEB causes a significant increase in IL-10 production in vivo. CPZ-mediated amplification of the SEB-driven CPZ secretion is accompanied by an enhanced IL-10 mRNA accumulation, as shown by PCR analysis and in situ hybridization. Determination of IL-10 production in mice lacking T cells, B cells, or phagocytes revealed that SEB + CPZ-induced IL-10 was produced by phagocytic cells, but not by lymphocytes, a finding that is in accord with the distribution of splenic cells transcribing the IL-10 gene in response to SEB + CPZ. Moreover, these data indicate that bacterial superantigen can directly stimulate tissue phagocytes, even in the virtual absence of T lymphocytes. The blockade of dopamine type 1 (D1) but not type 2 (D2) receptors abolishes the CPZ effect on IL-10 production. Inhibition of Th1 and Th2 lymphokine production by CPZ is not mediated by dopamine receptors and is independent of IL-10 up-regulation. These findings may explain the mechanism by which CPZ and related drugs enhance humoral autoimmune reactions, block cellular immune responses, and prevent lethal septic shock in vivo.

Pertussis toxin interferes with superantigen-induced deletion of peripheral T cells without affecting T cell activation in vivo. Inhibition of deletion and associated programmed cell death depends on ADP-ribosyltransferase activity

Intravenous injection of a bacterial superantigen such as Staphylococcus aureus enterotoxin B (SEB) causes transient activation and expansion of SEB-reactive V beta 8+ T cells, as well as specific down-regulation of the immune response, through partial deletion of superantigen-reactive T cells. Here we demonstrate that co-administration of pertussis toxin (PTX) and SEB reduces the SEB-induced deletion of V beta 8+ T cells, although it does not affect T cell activation and proliferation. PTX abrogates the SEB-driven deletion of V beta 8+CD4+ (not V beta 8+CD8+) splenocytes that is observed early (12-24 h) after SEB injection. Moreover, it antagonizes the late (&gt; or = 4 days) deletion of V beta 8+CD4+ and V beta 8+CD8+ peripheral T cells that follows transient expansion of such cells. This phenomenon is associated with significant reductions in apoptosis and endonucleolysis and is not caused by a compensatory increase in proliferation of SEB-reactive T cells, as we determined by using a combined fluorometric analysis of cell cycle and DNA alterations, which are associated with programmed cell death. These effects are also observed in thymectomized animals, thus excluding the possibility that PTX might act by enhancing the maturation and export of thymic T cells to the periphery. Moreover, the SEB-induced reduction of V beta 8+ splenocytes is antagonized by PTX in vitro. The capacity of PTX to reduce clonal deletion depends critically on its ADP-ribosyltransferase activity, inasmuch as a non-enzymatic PTX mutant fails to act in this biologic system. We conclude that PTX selectively antagonizes or impedes the delivery of negative signals to T cells, which are stimulated by superantigens, without interfering with the transmission of stimulatory signals.

Pertussis toxin interferes with superantigen-induced deletion of peripheral T cells without affecting T cell activation in vivo. Inhibition of deletion and associated programmed cell death depends on ADP-ribosyltransferase activity

Intravenous injection of a bacterial superantigen such as Staphylococcus aureus enterotoxin B (SEB) causes transient activation and expansion of SEB-reactive V beta 8+ T cells, as well as specific down-regulation of the immune response, through partial deletion of superantigen-reactive T cells. Here we demonstrate that co-administration of pertussis toxin (PTX) and SEB reduces the SEB-induced deletion of V beta 8+ T cells, although it does not affect T cell activation and proliferation. PTX abrogates the SEB-driven deletion of V beta 8+CD4+ (not V beta 8+CD8+) splenocytes that is observed early (12-24 h) after SEB injection. Moreover, it antagonizes the late (> or = 4 days) deletion of V beta 8+CD4+ and V beta 8+CD8+ peripheral T cells that follows transient expansion of such cells. This phenomenon is associated with significant reductions in apoptosis and endonucleolysis and is not caused by a compensatory increase in proliferation of SEB-reactive T cells, as we determined by using a combined fluorometric analysis of cell cycle and DNA alterations, which are associated with programmed cell death. These effects are also observed in thymectomized animals, thus excluding the possibility that PTX might act by enhancing the maturation and export of thymic T cells to the periphery. Moreover, the SEB-induced reduction of V beta 8+ splenocytes is antagonized by PTX in vitro. The capacity of PTX to reduce clonal deletion depends critically on its ADP-ribosyltransferase activity, inasmuch as a non-enzymatic PTX mutant fails to act in this biologic system. We conclude that PTX selectively antagonizes or impedes the delivery of negative signals to T cells, which are stimulated by superantigens, without interfering with the transmission of stimulatory signals.

Differential in vivo effects of a superantigen and an antibody targeted to the same T cell receptor. Activation-induced cell death vs passive macrophage-dependent deletion

Superantigens have multiple pleiotropic effects in vivo, causing the activation, proliferation, and deletion of specific T cells. In our study, we analyzed the effects of the bacterial superantigen Staphylococcus aureus enterotoxin B (SEB) on peripheral T cells in vivo. As an internal control we took advantage of a IgG2a mAb, F23.1 (anti-V beta 8), that recognizes products from the same V beta gene family as that recognized by SEB. Suprisingly, not only SEB, but also F23.1 primes peripheral T cells to undergo oligonucleosomal DNA fragmentation typical for programmed cell death (PCD). Nonetheless the deletion and induction of PCD imposed by both agents obey rather different principles. First, SEB, not F23.1-induced PCD, concerns T cells that have passed through the S phase of the cell cycle, as demonstrated by experiments in which the thymidine analogue 5-bromo-2'desoxyuridine was detected in mono- and oligonucleosomal fragments of T cells undergoing PCD. Second, deletion of V beta 8+ T cells induced by SEB, not F23.1, can be blocked in vivo by high doses of retinol and, during the early phase, by glucocorticoid receptor blockade with RU-38486. Inasmuch as retinol fails to antagonize the glucocorticoid-induced PCD, at least two pathways are involved in early SEB-driven deletion, one that depends on the presence of endogenous glucocorticoid, and another that can be inhibited by retinol. Third, depletion of phagocytes in vivo by means of liposome-encapsulated dichloromethylene diphosphonate does not impede the activation and deletion of V beta 8+ cells by SEB, although it partially prevents the elimination of T cells binding F23.1 in vivo. Thus, macrophages are not rate-limiting for the action of SEB. In a further series of experiments, we demonstrate that SEB causes the secretion of a variety of cytokines (IL-1, -2, -4, -10, granulocyte-macrophage-CSF, IFN-gamma, and TNF) that may cause lethal septic shock. In contrast, F23.1 that efficiently induces all these mediators in vitro, fails to do so in vivo. In synthesis, the elimination of T cells induced by two different agents specific for V beta 8 obeys different principles: activation-induced cell death in the case of SEB and passive macrophage-mediated elimination in the case of F23.1.

Differential in vivo effects of a superantigen and an antibody targeted to the same T cell receptor. Activation-induced cell death vs passive macrophage-dependent deletion

Superantigens have multiple pleiotropic effects in vivo, causing the activation, proliferation, and deletion of specific T cells. In our study, we analyzed the effects of the bacterial superantigen Staphylococcus aureus enterotoxin B (SEB) on peripheral T cells in vivo. As an internal control we took advantage of a IgG2a mAb, F23.1 (anti-V beta 8), that recognizes products from the same V beta gene family as that recognized by SEB. Suprisingly, not only SEB, but also F23.1 primes peripheral T cells to undergo oligonucleosomal DNA fragmentation typical for programmed cell death (PCD). Nonetheless the deletion and induction of PCD imposed by both agents obey rather different principles. First, SEB, not F23.1-induced PCD, concerns T cells that have passed through the S phase of the cell cycle, as demonstrated by experiments in which the thymidine analogue 5-bromo-2'desoxyuridine was detected in mono- and oligonucleosomal fragments of T cells undergoing PCD. Second, deletion of V beta 8+ T cells induced by SEB, not F23.1, can be blocked in vivo by high doses of retinol and, during the early phase, by glucocorticoid receptor blockade with RU-38486. Inasmuch as retinol fails to antagonize the glucocorticoid-induced PCD, at least two pathways are involved in early SEB-driven deletion, one that depends on the presence of endogenous glucocorticoid, and another that can be inhibited by retinol. Third, depletion of phagocytes in vivo by means of liposome-encapsulated dichloromethylene diphosphonate does not impede the activation and deletion of V beta 8+ cells by SEB, although it partially prevents the elimination of T cells binding F23.1 in vivo. Thus, macrophages are not rate-limiting for the action of SEB. In a further series of experiments, we demonstrate that SEB causes the secretion of a variety of cytokines (IL-1, -2, -4, -10, granulocyte-macrophage-CSF, IFN-gamma, and TNF) that may cause lethal septic shock. In contrast, F23.1 that efficiently induces all these mediators in vitro, fails to do so in vivo. In synthesis, the elimination of T cells induced by two different agents specific for V beta 8 obeys different principles: activation-induced cell death in the case of SEB and passive macrophage-mediated elimination in the case of F23.1.

Linomide inhibits programmed cell death of peripheral T cells in vivo

Programmed cell death (PCD) is involved in the physiological regulation of lymphocyte turnover, as well in the antigen-driven selection of T and B cells. Here it is shown that the immunomodulator linomide (quinoline-3-carboxamide) inhibits the apoptotic decay of peripheral T lymphocytes in response to three different stimuli. First, linomide reduces the superantigen-mediated apoptosis and deletion of specific T lymphocytes of both the CD4+ and the CD8+ subsets without affecting other superantigen-triggered phenomena such as T cell expansion and anergy. Second, linomide abolishes the T lymphopenia and inhibits PCD of splenic CD4+ and CD8+ T cells induced by exogenous glucocorticoids. This effect is restricted to peripheral T lymphocytes and does not concern thymocytes. Finally, linomide abolishes the development of lymphopenia that follows infection with vaccinia virus, while reducing PCD of CD4+ and CD8+ peripheral T cells. The anti-apoptotic effect of linomide could account for its immunostimulatory properties and might be relevant to the treatment of immunodeficiencies associated with an increased apoptotic decay of T lymphocytes.

Linomide, a novel immunomodulator that prevents death in four models of septic shock

Intravenous injections of 50 micrograms Staphylococcus aureus enterotoxin B (SEB) or bacterial lipopolysaccharide (LPS) are lethal, provided that mice are simultaneously sensitized with either N-galactosamine (GalN) or the anti-glucocorticoid RU-38486. Similar to the synthetic glucocorticoid (GC) receptor agonist dexamethasone, pharmacological doses of the immunomodulator linomide (quinoline-3-carboxamide) prevent death in all four models of lethal septic shock (LPS + GalN, LPS + RU-38486, SEB + GalN, and SEB + RU-38486) and inhibit the secretion of tumor necrosis factor, one of the major intermediate effector molecules of SEB and LPS toxicity. In this system, cyclosporine A (CsA), although effective in suppressing SEB toxicity, fails to counteract the lethal effect of LPS. This observation, together with the fact that linomide acts in the presence of excess amounts of GC receptor antagonist, indicates that linomide functions in a different way to that of known immunosuppressive agents like CsA and GC.

Glucocorticoid-mediated control of the activation and clonal deletion of peripheral T cells in vivo

Poly- and oligoclonal T cell stimuli like anti-CD3 epsilon monoclonal antibody or Staphylococcus aureus enterotoxin B (SEB), injected at doses that per se are not lethal, provoke acute death within less than 24 h, provided that endogenous glucocorticoids (GC) are depleted by adrenalectomy or by injection of saturating amounts of the GC receptor antagonist RU-38486 (mifepristone). Pharmacological doses of the GC agonist dexamethasone (DEX) alter the in vivo response of splenic V beta 8+ T cells to SEB, thus impeding the expansion of such cells and causing their rapid (3 d) clonal deletion. In contrast, coadministration of RU-38486 counteracts a SEB-induced early (12 h) reduction of V beta 8+CD4+ and V beta 8+CD8+ spleen cells. In vivo T cell stimulation by injection of bacterial superantigen induces a rapid (peak at 90-120 min) increase in corticosterone serum levels, suggesting that endogenous GC might control early T cell activation. Accordingly, kinetic studies revealed that RU-38486 has to be administered within 2 h after superantigen administration to exert its lethal effect. Similarly, exogenous GC must be injected during this critical phase (2 h) to rescue animals from acute death induced by coinjection of SEB and D-galactosamine (GalN). Adrenalectomy, injection of RU-38486 and priming with GalN per se provoke the programmed death of peripheral CD4+ and CD8+ T cells. Thus, three manipulations that sensitize mice for the lethal effect of T cell stimulation also exert a proapoptotic effect on peripheral T cells. In synthesis, endogenous and exogenous GC regulate T cell responses and determine the propensity of peripheral T cells to undergo apoptosis.