Leptospiral lipopolysaccharide dampens inflammation through upregulation of autophagy adaptor p62 and NRF2 signaling in macrophages

Leptospira interrogans are pathogenic bacteria responsible for leptospirosis, a worldwide zoonosis. All vertebrates can be infected, and some species like humans are susceptible to the disease whereas rodents such as mice are resistant and become asymptomatic renal carriers. Leptospires are stealth bacteria that are known to escape several immune recognition pathways and resist killing mechanisms. We recently published that leptospires may survive intracellularly in and exit macrophages, avoiding xenophagy, a pathogen-targeting form of autophagy. Interestingly, the latter is one of the antimicrobial mechanisms often highjacked by bacteria to evade the host immune response. In this study we explored whether leptospires subvert the key molecular players of autophagy to facilitate infection. We showed in macrophages that leptospires triggered a specific accumulation of autophagy-adaptor p62 in puncta-like structures, without altering autophagic flux. We demonstrated that Leptospira-induced p62 accumulation is a passive mechanism depending on the leptospiral virulence factor LPS signaling via TLR4/TLR2. p62 is a central pleiotropic protein, also mediating cell stress and death, via the translocation of transcription factors. We demonstrated that Leptospira-driven accumulation of p62 induced the translocation of transcription factor NRF2, a key player in the anti-oxidant response. However, NRF2 translocation upon Leptospira infection did not result as expected in antioxydant response, but dampened the production of inflammatory mediators such as iNOS/NO, TNF and IL6. Overall, these findings highlight a novel passive bacterial mechanism linked to LPS and p62/NRF2 signaling that decreases inflammation and contributes to the stealthiness of leptospires.

The dangerous liaisons in innate immunity involving recombinant proteins and endotoxins: Examples from the literature and the Leptospira field

Endotoxins, also known as lipopolysaccharides (LPS), are essential components of cell walls of diderm bacteria such as Escherichia coli. LPS are microbe-associated molecular patterns that can activate pattern recognition receptors. While trying to investigate the interactions between proteins and host innate immunity, some studies using recombinant proteins expressed in E. coli reported interaction and activation of immune cells. Here, we set out to provide information on endotoxins that are highly toxic to humans and bind to numerous molecules, including recombinant proteins. We begin by outlining the history of the discovery of endotoxins, their receptors and the associated signaling pathways that confer extreme sensitivity to immune cells, acting alone or in synergy with other microbe-associated molecular patterns. We list the various places where endotoxins have been found. Additionally, we warn against the risk of data misinterpretation due to endotoxin contamination in recombinant proteins, which is difficult to estimate with the Limulus amebocyte lysate assay, and cannot be completely neutralized (e.g., treatment with polymyxin B or heating). We further illustrate our point with examples of recombinant heat-shock proteins and viral proteins from severe acute respiratory syndrome coronavirus 2, dengue and HIV, for which endotoxin contamination has eventually been shown to be responsible for the inflammatory roles previously ascribed. We also critically appraised studies on recombinant Leptospira proteins regarding their putative inflammatory roles. Finally, to avoid these issues, we propose alternatives to express recombinant proteins in nonmicrobial systems. Microbiologists wishing to undertake innate immunity studies with their favorite pathogens should be aware of these difficulties.

Leptospira interrogans Prevents Macrophage Cell Death and Pyroptotic IL-1β Release through Its Atypical Lipopolysaccharide

Leptospira interrogans are bacteria that can infect all vertebrates and are responsible for leptospirosis, a neglected zoonosis. Some hosts, such as humans, are susceptible to the disease, whereas mice are resistant and get chronically colonized. Although leptospires escape recognition by some immune receptors, they activate the NOD-like receptor pyrin 3-inflammasome and trigger IL-1β secretion. Classically, IL-1β secretion is associated with lytic inflammatory cell death called pyroptosis, resulting from cytosolic LPS binding to inflammatory caspases, such as caspase 11. Interestingly, we showed that L. interrogans and Leptospira biflexa do not trigger cell death in either murine, human, hamster, or bovine macrophages, escaping both pyroptosis and apoptosis. We showed, in murine cells, that the mild IL-1β secretion induced by leptospires occurred through nonlytic caspase 8-dependent gasdermin D pore formation and not through activation of caspase 11/noncanonical inflammasome. Strikingly, we demonstrated a potent antagonistic effect of pathogenic L. interrogans and their atypical LPS on spontaneous and Escherichia coli LPS-induced cell death. Indeed, LPS of L. interrogans efficiently prevents caspase 11 dimerization and subsequent massive gasdermin D cleavage. Finally, we showed that pyroptosis escape by leptospires prevents massive IL-1β release, and we consistently found no major role of IL-1R in controlling experimental leptospirosis in vivo. Overall, to our knowledge, our findings described a novel mechanism by which leptospires dampen inflammation, thus potentially contributing to their stealthiness.

Host and Species-Specificities of Pattern Recognition Receptors Upon Infection With Leptospira interrogans

Leptospirosis is a zoonotic infectious disease affecting all vertebrates. It is caused by species of the genus Leptospira, among which are the highly pathogenic L. interrogans. Different mammals can be either resistant or susceptible to the disease which can present a large variety of symptoms. Humans are mostly asymptomatic after infection but can have in some cases symptoms varying from a flu-like syndrome to more severe forms such as Weil’s disease, potentially leading to multiorgan failure and death. Similarly, cattle, pigs, and horses can suffer from acute forms of the disease, including morbidity, abortion, and uveitis. On the other hand, mice and rats are resistant to leptospirosis despite chronical colonization of the kidneys, excreting leptospires in urine and contributing to the transmission of the bacteria. To this date, the immune mechanisms that determine the severity of the infection and that confer susceptibility to leptospirosis remain enigmatic. To our interest, differential immune sensing of leptospires through the activation of or escape from pattern recognition receptors (PRRs) by microbe-associated molecular patterns (MAMPs) has recently been described. In this review, we will summarize these findings that suggest that in various hosts, leptospires differentially escape recognition by some Toll-like and NOD-like receptors, including TLR4, TLR5, and NOD1, although TLR2 and NLRP3 responses are conserved independently of the host. Overall, we hypothesize that these innate immune mechanisms could play a role in determining host susceptibility to leptospirosis and suggest a central, yet complex, role for TLR4.

Alive Pathogenic and Saprophytic Leptospires Enter and Exit Human and Mouse Macrophages With No Intracellular Replication

Leptospira interrogans are pathogenic bacteria responsible for leptospirosis, a zoonosis impacting 1 million people per year worldwide. Leptospires can infect all vertebrates, but not all hosts develop similar symptoms. Human and cattle may suffer from mild to acute illnesses and are therefore considered as sensitive to leptospirosis. In contrast, mice and rats remain asymptomatic upon infection, although they get chronically colonized in their kidneys. Upon infection, leptospires are stealth pathogens that partially escape the recognition by the host innate immune system. Although leptospires are mainly extracellular bacteria, it was suggested that they could also replicate within macrophages. However, contradictory data in the current literature led us to reevaluate these findings. Using a gentamicin–protection assay coupled to high-content (HC) microscopy, we observed that leptospires were internalized in vivo upon peritoneal infection of C57BL/6J mice. Additionally, three different serotypes of pathogenic L. interrogans and the saprophytic L. biflexa actively infected both human (PMA differentiated) THP1 and mouse RAW264.7 macrophage cell lines. Next, we assessed the intracellular fate of leptospires using bioluminescent strains, and we observed a drastic reduction in the leptospiral intracellular load between 3 h and 6 h post-infection, suggesting that leptospires do not replicate within these cells. Surprisingly, the classical macrophage microbicidal mechanisms (phagocytosis, autophagy, TLR–mediated ROS, and RNS production) were not responsible for the observed decrease. Finally, we demonstrated that the reduction in the intracellular load was associated with an increase of the bacteria in the supernatant, suggesting that leptospires exit both human and murine macrophages. Overall, our study reevaluated the intracellular fate of leptospires and favors an active entrance followed by a rapid exit, suggesting that leptospires do not have an intracellular lifestyle in macrophages.

Leptospiral LPS escapes mouse TLR4 internalization and TRIF‑associated antimicrobial responses through O antigen and associated lipoproteins

Leptospirosis is a worldwide re-emerging zoonosis caused by pathogenic Leptospira spp. All vertebrate species can be infected; humans are sensitive hosts whereas other species, such as rodents, may become long-term renal carrier reservoirs. Upon infection, innate immune responses are initiated by recognition of Microbial Associated Molecular Patterns (MAMPs) by Pattern Recognition Receptors (PRRs). Among MAMPs, the lipopolysaccharide (LPS) is recognized by the Toll-Like-Receptor 4 (TLR4) and activates both the MyD88-dependent pathway at the plasma membrane and the TRIF-dependent pathway after TLR4 internalization. We previously showed that leptospiral LPS is not recognized by the human-TLR4, whereas it signals through mouse-TLR4 (mTLR4), which mediates mouse resistance to acute leptospirosis. However, although resistant, mice are known to be chronically infected by leptospires. Interestingly, the leptospiral LPS has low endotoxicity in mouse cells and is an agonist of TLR2, the sensor for bacterial lipoproteins. Here, we investigated the signaling properties of the leptospiral LPS in mouse macrophages. Using confocal microscopy and flow cytometry, we showed that the LPS of L. interrogans did not induce internalization of mTLR4, unlike the LPS of Escherichia coli. Consequently, the LPS failed to induce the production of the TRIF-dependent nitric oxide and RANTES, both important antimicrobial responses. Using shorter LPS and LPS devoid of TLR2 activity, we further found this mTLR4-TRIF escape to be dependent on both the co-purifying lipoproteins and the full-length O antigen. Furthermore, our data suggest that the O antigen could alter the binding of the leptospiral LPS to the co-receptor CD14 that is essential for TLR4-TRIF activation. Overall, we describe here a novel leptospiral immune escape mechanism from mouse macrophages and hypothesize that the LPS altered signaling could contribute to the stealthiness and chronicity of the leptospires in mice.

Leptospira interrogans is a bacterial pathogen, responsible for leptospirosis, a worldwide neglected reemerging disease. L. interrogans may cause an acute severe disease in humans, whereas rodents and other animals asymptomatically carry the leptospires in their kidneys. They can therefore excrete live bacteria in urine and contaminate the environment. Leptospires are stealth pathogens known to escape the innate immune defenses of their hosts. They are covered in lipopolysaccharide (LPS), a bacterial motif recognized in mammals through the Toll-like receptor 4 (TLR4), which triggers two different signaling pathways. We showed previously that pathogenic leptospires fully escape TLR4 recognition in humans. Here we focused on the LPS signaling in mice that are, although resistant to acute leptospirosis, chronically infected. We showed in mouse cells that the leptospiral LPS triggers only one arm of the TLR4 pathway and escapes the other, hence avoiding production of antimicrobial compounds. Removing the lipoproteins that always co-purify with the leptospiral LPS, or using shorter LPS, restores the stimulation of both pathways. This suggests a novel escape mechanism linked to the LPS and involving lipoproteins that could be instrumental for leptospires to escape the mouse defense and to allow for their chronic renal colonization.

Escape of TLR5 Recognition by Leptospira spp.: A Rationale for Atypical Endoflagella

Leptospira (L.) interrogans are invasive bacteria responsible for leptospirosis, a worldwide zoonosis. They possess two periplasmic endoflagellae that allow their motility. L. interrogans are stealth pathogens that escape the innate immune recognition of the NOD-like receptors NOD1/2, and the human Toll-like receptor (TLR)4, which senses peptidoglycan and lipopolysaccharide (LPS), respectively. TLR5 is another receptor of bacterial cell wall components, recognizing flagellin subunits. To study the contribution of TLR5 in the host defense against leptospires, we infected WT and TLR5 deficient mice with pathogenic L. interrogans and tracked the infection by in vivo live imaging of bioluminescent bacteria or by qPCR. We did not identify any protective or inflammatory role of murine TLR5 for controlling pathogenic Leptospira. Likewise, subsequent in vitro experiments showed that infections with different live strains of L. interrogans and L. biflexa did not trigger TLR5 signaling. However, unexpectedly, heat-killed bacteria stimulated human and bovine TLR5, but did not, or barely induced stimulation via murine TLR5. Abolition of TLR5 recognition required extensive boiling time of the bacteria or proteinase K treatment, showing an unusual high stability of the leptospiral flagellins. Interestingly, after using antimicrobial peptides to destabilize live leptospires, we detected TLR5 activity, suggesting that TLR5 could participate in the fight against leptospires in humans or cattle. Using different Leptospira strains with mutations in the flagellin proteins, we further showed that neither FlaA nor Fcp participated in the recognition by TLR5, suggesting a role for the FlaB. FlaB have structural homology to Salmonella FliC, and possess conserved residues important for TLR5 activation, as shown by in silico analyses. Accordingly, we found that leptospires regulate the expression of FlaB mRNA according to the growth phase in vitro, and that infection with L. interrogans in hamsters and in mice downregulated the expression of the FlaB, but not the FlaA subunits. Altogether, in contrast to different bacteria that modify their flagellin sequences to escape TLR5 recognition, our study suggests that the peculiar central localization and stability of the FlaB monomers in the periplasmic endoflagellae, associated with the downregulation of FlaB subunits in hosts, constitute an efficient strategy of leptospires to escape the TLR5 recognition and the induced immune response.

Cytokinin promotes flowering of Arabidopsis via transcriptional activation of the FT paralogue TSF

Cytokinins are involved in many aspects of plant growth and development, and physiological evidence also indicates that they have a role in floral transition. In order to integrate these phytohormones into the current knowledge of genetically defined molecular pathways to flowering, we performed exogenous treatments of adult wild type and mutant Arabidopsis plants, and analysed the expression of candidate genes. We used a hydroponic system that enables synchronous growth and flowering of Arabidopsis, and allows the precise application of chemicals to the roots for defined periods of time. We show that the application of N⁶-benzylaminopurine (BAP) promotes flowering of plants grown in non-inductive short days. The response to cytokinin treatment does not require FLOWERING LOCUS T (FT), but activates its paralogue TWIN SISTER OF FT (TSF), as well as FD, which encodes a partner protein of TSF, and the downstream gene SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1). Treatment of selected mutants confirmed that TSF and SOC1 are necessary for the flowering response to BAP, whereas the activation cascade might partially act independently of FD. These experiments provide a mechanistic basis for the role of cytokinins in flowering, and demonstrate that the redundant genes FT and TSF are differently regulated by distinct floral-inducing signals.

Shortening the immunodeficient period after hematopoietic stem cell transplantation

The delayed reconstitution of the T-lymphoid compartment represents a major clinical challenge after HLA-mismatched hematopoietic stem cell transplantation. The generation of new T lymphocytes deriving from transplanted hematopoietic stem cells requires several months, a period associated with an increased risk of opportunistic infections and relapses. Recently, the early steps of human lymphopoiesis and the nature of the thymus-seeding progenitors were described. Moreover several scientific groups succeeded to generate T-cell precursors from murine and human hematopoietic stem cells in vitro by transitory exposition to Notch-ligands. Here we summarize and discuss these results and their possible usage in the development of new cell therapies to shorten the immunodeficient period following hematopoietic stem cell transplantation.

Gene activation cascade triggered by a single photoperiodic cycle inducing flowering in Sinapis alba

Molecular genetic analyses in Arabidopsis disclosed a genetic pathway whereby flowering is induced by the photoperiod. This cascade is examined here within the time course of floral transition in the long-day (LD) plant Sinapis alba induced by a single photoperiodic cycle. In addition to previously available sequences, the cloning of CONSTANS (SaCO) and FLOWERING LOCUS T (SaFT) homologues allowed expression analyses to be performed to follow the flowering process step by step. A diurnal rhythm in SaCO expression in the leaves was observed and transcripts of SaFT were detected when light was given in phase with SaCO kinetics only. This occurred when day length was extended or when a short day was shifted towards a 'photophile phase'. The steady-state level of SaFT transcripts in the various physiological situations examined was found to correlate like a rheostat with floral induction strength. Kinetics of SaFT activation were also consistent with previous estimations of translocation of florigen out of leaves, which could actually occur after the inductive cycle. In response to one 22-h LD, initiation of floral meristems by the shoot apical meristem (SAM) started about 2 days after activation of SaFT and was marked by expression of APETALA1 (SaAP1). Meanwhile, LEAFY (SaLFY) was first up-regulated in leaf primordia and in the SAM. FRUITFULL (SaFUL) was later activated in the whole SAM but excluded from floral meristems. These patterns are integrated with previous observations concerning upregulation of SUPPRESSOR OF OVEREXPRESSION OF CO1 (SaSOC1) to provide a temporal and spatial map of floral transition in Sinapis.

A human postnatal lymphoid progenitor capable of circulating and seeding the thymus

Identification of a thymus-seeding progenitor originating from human bone marrow (BM) constitutes a key milestone in understanding the mechanisms of T cell development and provides new potential for correcting T cell deficiencies. We report the characterization of a novel lymphoid-restricted subset, which is part of the lineage-negative CD34(+)CD10(+) progenitor population and which is distinct from B cell-committed precursors (in view of the absence of CD24 expression). We demonstrate that these Lin(-)CD34(+)CD10(+)CD24(-) progenitors have a very low myeloid potential but can generate B, T, and natural killer lymphocytes and coexpress recombination activating gene 1, terminal deoxynucleotide transferase, PAX5, interleukin 7 receptor alpha, and CD3epsilon. These progenitors are present in the cord blood and in the BM but can also be found in the blood throughout life. Moreover, they belong to the most immature thymocyte population. Collectively, these findings unravel the existence of a postnatal lymphoid-polarized population that is capable of migrating from the BM to the thymus.

Restoration of human B-cell differentiation into NOD-SCID mice engrafted with gene-corrected CD34+ cells isolated from Artemis or RAG1-deficient patients

Severe combined immunodeficiency (SCID) caused by mutation of the recombination-activating gene 1 (RAG1) or Artemis gene lead to the absence of B- and T-cell differentiation. The only curative treatment is allogeneic bone marrow (BM) transplantation, which displays a high survival rate when an HLA compatible donor is available but has a poorer prognosis when the donor is partially compatible. Consequently, gene therapy may be a promising alternative strategy for these diseases. Here, we report that lentiviral gene-corrected BM CD34(+) cells (isolated from Artemis- or RAG1-deficient patients) sustain human B-cell differentiation following injection into non-obese diabetic/SCID (NOD-SCID) mice previously infused with anti-interleukin-2 receptor beta chain monoclonal antibody. In most of the mice BM, engrafted with Artemis-transduced cells, human B-cell differentiation occurred until the mature stage. The B cells were functional as human immunoglobulin M (IgM) was present in the serum. Following injection with RAG1-transduced cells, human engraftment occurred in vivo but B-cell differentiation until the mature stage was less frequent. However, when it occurred, it was always associated with human IgM production. This overall approach represents a useful tool for evaluating gene transfer efficiency in human SCID forms affecting B-cell development (such as Artemis deficiency) and for testing new vectors for improving in vivo RAG1 complementation.

IL-7 effect on immunological reconstitution after HSCT depends on MHC incompatibility

Considerable progress has been recently accomplished in the management of patients who have undergone haplo-incompatible haematopoietic stem cell transplantation (HSCT) in terms of intake and prevention of graft-versus-host disease. Nevertheless haplo-incompatible HSCT is a procedure limited to a small number of patients because of the long-lasting immunodeficiency that is responsible for more than 50% of deaths within the first 3 months. Interleukin (IL)-7, which plays a unique and key role in T-cell development both in the mouse and in the human, is particularly attractive for attempting to speed up T-cell reconstitution. However, controversial results have been obtained after bone marrow graft in murine and primate models. To elucidate the impact of IL-7 treatment, we have performed HSCT in irradiated murine recombination activating gene (RAG) immunodeficient recipients, using donors that exhibited increased major histocompatibilty complex (MHC) incompatibility. Although irradiation performed prior to HSCT lead to a profound defect in the thymic stromal cells responsible for IL-7 production, IL-7 treatment had no significant effect on immune reconstitution in the MHC compatible and partially compatible settings. Interestingly, in the MHC fully incompatible setting in which only one-third of the recipients demonstrated active thymopoiesis, probably because of the rejection of donor cells by host natural killer cells, IL-7 treatment had a beneficial effect on T-cell development.

Characterization of antigen-specific repertoire diversity following in vitro restimulation by a recombinant adenovirus expressing human cytomegalovirus pp65

Human cytomegalovirus (HCMV) and adenovirus cause significant morbidity and mortality in immunocompromised hosts undergoing allogeneic stem cell transplantation. We have previously established a procedure for the generation of polyclonal CTL with specificity against adenovirus and HCMV using a recombinant adenovirus encoding the HCMV pp65 protein (RAdpp65). However, specific CTL expanded after in vitro culture steps were subjected to several in vitro restimulations and, depending on the protocol adopted, this could lead to a selection bias, compromising the clinical benefit. To determine which part of the memory repertoire is selected after in vitro restimulation, we have followed the specificity and clonal composition of pp65-peptide-specific CD8(+) T cells in HLA-A*201 individuals before and after repeated in vitro restimulation of cells with RAdpp65, combining HLA tetrameric complexes and immunoscope analysis. Tetramer staining showed that, after in vitro restimulation, up to 60% of CD8(+) T cells were virus-specific. Immunoscope analysis showed that the predominant TCRBV diversity of pp65-specific clones was conserved, demonstrating that the memory repertoire was preserved all along the procedure. Altogether, these results suggest that the use of RAdpp65 to induce CMV- and adenovirus-specific CTL maybe appropriate for immunotherapy.

Impaired antibody affinity maturation process characterizes a subset of patients with common variable immunodeficiency

Common variable immunodeficiency (CVID) is an heterogeneous syndrome characterized by decreased levels of serum Ig and recurrent bacterial infection. Here, we were interested to study whether a qualitative defect of the affinity Ab maturation process could be combined to the low level of serum Ig in a cohort of 38 CVID patients. For this, we designed a novel and rapid screening test for the detection of hypomutated V gene expressed by memory B cells. This test delineated a subset of 9/38 (23%) CVID patients with an abnormal pattern of Ig V gene mutation. The mean frequency of V gene mutation of this subset was significantly lower (1.74%) compared with other CVID patients (5.46%) and normal donors (6.5%) (p<0.0001). The mean age of this subgroup was significantly higher than other hypogammaglobulinemic patients with normal levels of V gene mutation (p<0.02), whereas no difference in the duration of symptoms was noted between the two groups. This suggests that hypomutation characterizes patients who began CVID late in life. Recently, it was shown that non-Ig sequences, such as the intronic BCL-6 gene, could be the target of the somatic hypermutation process in normal memory B cells. Our finding of a normal mutation frequency of the BCL-6 gene in two hypomutated CVID point to a defect of the Ig targeting of hypermutation machinery in these cases.

Amisulpride has a superior benefit/risk profile to haloperidol in schizophrenia: results of a multicentre, double-blind study (the Amisulpride Study Group)

In a multicentre, double-blind, flexible-dose study, 199 patients with paranoid schizophrenia or schizophreniform disorders received haloperidol (10-30 mg/d) or amisulpride (400-1200 mg/d) for four months. More patients in the haloperidol group withdrew prematurely (44% vs 26%; P = 0.0077) due to a higher incidence of adverse events. Amisulpride was at least as effective as haloperidol in reducing the Brief Psychiatric Rating Scale (BPRS) total score (-27.3 vs -21.9) (non-inferiority test; P < 0.001). The PANSS positive score improved to a similar extent in both groups whilst improvement in the PANSS negative score was significantly greater with amisulpride (-10.5 vs -7.2; P = 0.01). The percentage of responders on the Clinical Global Impression scale was also significantly greater with amisulpride (71% vs 47%; P < 0.001). Both the Quality of Life Scale (QLS) and the Functional Status Questionnaire (FSQ) improved to a significantly greater extent under amisulpride. Haloperidol was associated with a greater incidence in extrapyramidal symptoms and with a greater increase in the Simpson-Angus score than was seen with amisulpride (0.32 vs 0.02; P < 0.001). In conclusion, amisulpride is globally superior to haloperidol in the treatment of acute exacerbations of schizophrenia and significantly improves patients' quality of life and social adjustment.

Double blind study of tiapride versus haloperidol and placebo in agitation and aggressiveness in elderly patients with cognitive impairment

OBJECTIVE

The aim of the present study was to compare the efficacy and safety of tiapride versus haloperidol and placebo in the treatment of agitation and aggressiveness in elderly patients with mild or moderate mental impairment.

METHOD

This international, multicentre, randomized, double blind, three parallel groups study compared efficacy and safety of a 21 -day regimen of tiapride 100-300 mg/day versus haloperidol 2-6 mg/day and placebo in 306 elderly patients with mild or moderate dementia according to DSM III R and behavioural troubles with the Multidimensional Observation Scale for the Elderly Subjects (MOSES) irritability/aggressiveness subscore ranging from 16 to 30.

RESULTS

The percentage of responders (defined as patients with at least a 25% MOSES irritability/aggressiveness subscore decrease between the inclusion and the end of the treatment) was significantly greater in the tiapride (63%, P=0.04) and haloperidol (69%, P=0.004) groups than in the placebo group (49%), with no significant difference between the active drugs. Similar results were observed for the mean MOSES irritability/aggressiveness subscores on D7, D21 and at D(end) which were significantly smaller in the tiapride and haloperidol groups than in the placebo group. The decrease between D0 and D(end) was significantly greater in the tiapride (6.57, P=0.009) and haloperidol groups (6.75, P=0.005) than in the placebo group (4.71). The global improvement CGI was significantly better in the tiapride and haloperidol groups than in the placebo group (P=0.03 and P=0.02). No significant difference was observed between the two active drugs or among the three treatment groups for the Folstein's Mini Mental Status scale (MMS) total score, and there was no notable change during treatment. The number of patients with adverse events, assessed on the Udvalg Kliniske Undersogelser scale (UKU), and the number of UKU symptoms were smaller in the tiapride group (62 patients, 61%, 212 events) than in the haloperidol group (77 patients, 76%, 305 events) and identical to that observed in the placebo group (69 patients, 67%, 234 events). Of interest, the number of patients with at least one extrapyramidal symptom was significantly lower (P=0.003) in the tiapride group (16 patients, 16%) than in the haloperidol group (34 patients, 34%) and similar to that of the placebo group (18 patients, 17%); the difference observed between the haloperidol and placebo groups was significant (P=0.008).

CONCLUSION

Tiapride is not different from haloperidol in the treatment of agitation and aggressiveness in elderly patients and better tolerated, in particular with significantly fewer extrapyramidal symptoms.

Effects of tiapride on electroencephalograms and cognitive functions in the elderly

Tiapride is a substituted benzamide with selective dopamine D2 and D3-antagonist properties which appears to have preferential affinity for extra-striatal dopamine receptors. Tiapride is used in the treatment of agitation, aggressiveness and anxiety in the elderly. To define the effects of a single dose of tiapride 100 mg on psychomotor performance and cognitive functions and electroencephalogram (EEG), a randomized, double-blind, three-way crossover, placebo-controlled study using lorazepam 1 mg as a positive control was carried out in 12 elderly individuals (six women and six men, mean age +/- SD: 69 +/- 3 years). A 1-week wash-out interval was allowed between each administration. Psychomotor and cognitive functions were assessed using both objective [EEG, critical flicker fusion, simple reaction time, tapping, body sway, continuous performance task (CPT), digit symbol substitution test, Sternberg memory scanning and a learning memory test using word lists] and subjective (visual analogue scales) measures before and up to 6 h after dosing. Tiapride was devoid of any detrimental or sedative effects on EEG and all of the performance tasks used and did not impair memory compared with-placebo. In contrast, a single dose of lorazepam produced significant deleterious effects on psychomotor performance (decrease in tapping and in sustained attention (CPT) and an increase in reaction time and body sway), and sedative effects on EEG (significant increase in delta and decrease in alpha waves) as well as significant impairment in working memory (Sternberg) and anterograde amnesia (decrease in immediate and delayed free recall) up to 6 h after dosing compared with placebo and tiapride. In conclusion, the present study showed that in contrast to lorazepam 1 mg there is no evidence to suggest that a single dose of tiapride 100 mg has any sedative and amnestic effects in the elderly which may interfere with everyday life activities.

Antileukemic HLA-restricted T-cell clones generated with naturally processed peptides eluted from acute myeloblastic leukemia blasts

Recent studies have shown that transfusions of HLA-compatible donor lymphocytes may induce complete remission in marrow-grafted patients with relapses of acute myeloblastic leukemia (AML). We investigated the in vitro generation of antileukemia T-cell clones obtained from the peripheral blood mononuclear cells of a partially HLA-compatible donor (HLA-A2 and B7 molecules in common with the leukemic blasts) after stimulation with a pool of naturally processed peptides extracted from leukemic blast cells collected at diagnosis from a patient with hyperleucocytosis AML. We recovered a significant quantity of peptides that bound to the HLA-A2 or HLA-B7 molecules that were able to induce cytolytic T-lymphocyte (CTL) lines and clones specific for the eluted AML peptides and restricted to the HLA-A2 or B7 molecules. Such CTL line did not recognize the patient's nonleukemic cells, and one clone was able to interact with the leukemic blasts from which the naturally processed peptides had been eluted. Such T-cell clones might provide a rationale for the development of adoptive immunotherapy and could be used to improve the efficiency of HLA-compatible T-lymphocyte transfusions and the graft-versus-leukemia response in patients with AML.