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Supplementary Figures S1-S3 from Localization of Fas/CD95 into the Lipid Rafts on Down-Modulation of the Phosphatidylinositol 3-Kinase Signaling Pathway

Activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway is known to protect tumor cells from apoptosis and more specifically from the Fas-mediated apoptotic signal. The antitumoral agent edelfosine sensitizes leukemic cells to death by inducing the redistribution of the apoptotic receptor Fas into plasma membrane subdomains called lipid rafts. Herein, we show that inhibition of the PI3K signal by edelfosine triggers a Fas-mediated apoptotic signal independently of the Fas/FasL interaction. Furthermore, similarly to edelfosine, blockade of the PI3K activity, using specific inhibitors LY294002 and wortmannin, leads to the clustering of Fas whose supramolecular complex is colocalized within the lipid rafts. These findings indicate that the antitumoral agent edelfosine down-modulates the PI3K signal to sensitize tumor cells to death through the redistribution of Fas into large platform of membrane rafts. (Mol Cancer Res 2008;6(4):604–13)

Fas triggering by agonistic antibodies or by its cognate ligand, FasL, induces apoptotic cell death, whereas mutation in the Fas death domain is associated with lymphoma progression. On prolonged culture in the presence of an agonistic anti-Fas antibody, we raised a Jurkat cell line resistant to agonistic antibodies but still sensitive to soluble FasL, which carried at the heterozygous state, a point mutation into the Fas death domain. Down-modulation of c-FLIP expression reversed the blockade of the Fas pathway. We show that the activation threshold for the Fas receptor is more easily overcome by multimeric FasL than by agonistic antibodies and that the increase of this threshold due to mutation in the Fas death domain can be overcome by acting on a downstream effector of the Fas signal, c-FLIP. These findings put forward a new approach to eradicate Fas-resistant tumor cells. [Cancer Res 2007;67(1):108–15]

Supplementary Figures 1-2 from Dominant-Negative Fas Mutation Is Reversed by Down-expression of c-FLIP

Cytomegalovirus (CMV) is a major infectious cause of death and disease after transplantation. We have previously demonstrated that the tissue-associated adaptive Vδ2neg γδ T cells are key effectors responding to CMV and associated with recovery, contrasting with their innatelike circulating counterparts, the Vγ9posVδ2pos T cells that respond to phosphoantigens but not to CMV. A third Vγ9negVδ2pos subgroup with adaptive functions has been described in adults. In the current study, we demonstrate that these Vγ9negVδ2pos T cells are also components of the CMV immune response while presenting with distinct characteristics from Vδ2neg γδ T cells. In a cohort of kidney transplant recipients, CMV seropositivity was the unique clinical parameter associated with Vγ9negVδ2pos T-cell expansion and differentiation. Extensive phenotyping demonstrated their substantial cytotoxic potential and activation during acute CMV primary infection or reinfection. In vitro, Vγ9negVδ2pos T cells responded specifically to CMV-infected cells in a T-cell receptor–dependent manner and through strong interferon γ production. Finally, Vγ9negVδ2pos T cells were the only γδ T-cell subset in which expansion was tightly correlated with the severity of CMV disease. To conclude, our results identify a new player in the immune response against CMV and open interesting clinical perspectives for using Vγ9negVδ2pos T cells as an immune marker for CMV disease severity in immunocompromised patients.

International audience; Human γδ T cells contribute to tissue homeostasis and participate in epithelial stress surveillance through mechanisms that are not well understood. Here, we identified ephrin type-A receptor 2 (EphA2) as a stress antigen recognized by a human Vγ9Vδ1 TCR. EphA2 is recognized coordinately by ephrin A to enable γδ TCR activation. We identified a putative TCR binding site on the ligand-binding domain of EphA2 that was distinct from the ephrin A binding site. Expression of EphA2 was up-regulated upon AMP-activated protein kinase (AMPK)-dependent metabolic reprogramming of cancer cells, and coexpression of EphA2 and active AMPK in tumors was associated with higher CD3 T cell infiltration in human colorectal cancer tissue. These results highlight the potential of the human γδ TCR to cooperate with a co-receptor to recognize non-MHC-encoded proteins as signals of cellular dysregulation, potentially allowing γδ T cells to sense metabolic energy changes associated with either viral infection or cancer.

The editors are publishing this note to alert readers to concerns about [this article][1] ([1][2]). The same Western blot analysis image was used for Jurkat-R cells in Fig. 4A and for Jurkat parental cells in Fig. 1B of another article previously published by the authors ([2][3]). In addition, lane

During Plasmodium falciparum infections, erythrocyte-stage parasites inhibit dendritic cell maturation and function; compromising development of effective anti-malarial adaptive immunity. Human Vγ9Vδ2 T-cells can act in vitro as APCs and induce αβ T-cell activation. However, the relevance of this activity in pathophysiological contexts in vivo has remained elusive. Since Vγ9Vδ2 T-cells are activated during the early immune response against P.falciparum infection, we investigated whether they could contribute to the instruction of adaptive immune responses toward malaria parasites. In P.falciparum-infected patients,Vγ9Vδ2 T-cells presented an increased surface expression of APC-associated markers HLA-DR and CD86. In response to infected red blood cells in vitro, Vγ9Vδ2 T-cells readily up-regulated surface expression of HLA-DR, HLA-ABC, CD40, CD80, CD83 and CD86, induced naive αβ T-cell responses, and cross-presented soluble prototypical protein to antigen-specific CD8+ T-cells. Our findings indicate that P. falciparum parasites induce genuine APC properties in Vγ9Vδ2 T-cells and qualify this subset as an alternative professional APC in malaria patients, which could be harnessed for therapeutic interventions and vaccine design.

[This corrects the article DOI: 10.1371/journal.pbio.1001090.].

International audience; In this commentary of Koonin's target paper, we defend an extended view of CRISPR-Cas immunity by arguing that CRISPR-Cas includes, but cannot be reduced to, defence against nonself. CRISPR-Cas systems can target endogenous elements (for example in DNA repair) and tolerate exogenous elements (for example some phages). We conclude that the vocabulary of "defence" and "nonself" might be misleading when describing CRISPR-Cas systems. 2

Background Rabbit antithymocyte globulin (rATG) induction is associated with profound immunosuppression, leading to a higher risk of cytomegalovirus (CMV) infection compared with anti–interleukin 2 receptor antibody (anti–IL-2RA). However, this risk, depending on the baseline CMV serological recipient/donor status, is still controversial. Methods The CMV DNAemia-free survival between rATG- and anti–IL-2RA–treated patients was analyzed in donor-positive/recipient-negative (D+R−) and recipient-positive (R+) patients in 1 discovery cohort of 559 kidney transplant recipients (KTRs) and 2 independent cohorts (351 and 135 kidney KTRs). The CMV-specific cell-mediated immunity (CMI) at baseline and at different time points after transplantation was assessed using an interferon γ enzyme-linked immunosorbent spot assay. Results rATG increased the risk of CMV DNAemia in R+ but not in D+R− KTRs. In R+ CMI-positive (CMI+) patients, the CMV DNAemia rate was higher in rATG-treated than in anti–IL-2RA–treated patients; no difference was observed among R+ CMI-negative (CMI−) patients. Longitudinal follow-up demonstrated a deeper depletion of preformed CMV CMI in R+ rATG-treated patients. Conclusions D+R− KTRs have the highest risk of CMV DNAemia, but rATG adds no further risk. Among R+ KTRs, we described 3 groups, the least prone being R+CMI+ KTRs without rATG, then R+CMI+ KTRs with rATG, and finally R+CMI− KTRs. CMV serostatus, baseline CMV-specific CMI, and induction therapy may lead to personalized preventive therapy in further studies.

Universal prophylaxis for cytomegalovirus (CMV) prevention is viable but, compared with a preemptive strategy, leads to higher incidence of late-onset disease (LOD) associated with poor patient and graft survival. The purpose of this study was to compare LOD with early onset disease (EOD), with a focus on the highest risk kidney transplant recipients (KTRs): CMV seronegative recipients transplanted from seropositive donors (D+R-). Since CMV control depends on both antiviral treatment and specific immune response, we also compared Vδ2-negative (Vδ2(neg) ) γδ T cell expansion involved in CMV infection resolution. EOD was defined as occurring3 mo and LOD as occurring3 mo after transplantation. Depending on the period, universal prophylaxis or preemptive treatment was used. Overall, 168 D+R- KTRs were included between 2003 and 2011. LOD was associated with a lower peak DNAemia (p = 0.04), fewer recurrences (odds ratio 0.16; 95% confidence interval 0.05-0.55; p = 0.01) and shorter anti-CMV curative treatment (40 vs. 60 days, p0.0001). As a corollary, we found that Vδ2(neg) γδ T cell expansion was faster in LOD than in EOD (31 vs. 168 days after the beginning of CMV disease, p0.0001). In D+R- KTRs, universal prophylaxis is associated with more LOD, which had better infection management and a faster immune response. These results support the use of universal prophylaxis over a preemptive strategy and reappraise outcomes of LOD.

Anti-HLA donor-specific antibodies are deleterious for organ transplant survival. Class I HLA donor-specific antibodies are identified by using the Luminex single antigen beads (LSAB) assay, which also detects anti-denatured HLA antibodies (anti-dHLAs). Anti-dHLAs are thought to be unable to recognize native HLA (nHLA) on the cell surface and therefore to be clinically irrelevant. Acid denaturation of nHLA on LSAB allows anti-dHLAs to be discriminated from anti-nHLAs. We previously defined a threshold for the ratio between mean fluorescence intensity against acid-treated (D for denaturation) and nontreated (N) LSAB, D ≥ 1.2 N identifying the anti-dHLAs. However, some anti-dHLAs remained able to bind nHLA on lymphocytes in flow cytometry crossmatches, and some anti-nHLAs conserved significant reactivity toward acid-treated LSAB. After depleting serum anti-nHLA reactivity with HLA-typed cells, we analyzed the residual LSAB reactivity toward nontreated and acid-treated LSABs, and then evaluated the ability of antibodies to recognize nHLA alleles individually. We observed that sera can contain mixtures of anti-nHLAs and anti-dHLAs, or anti-nHLAs recognizing acid-resistant epitopes, all possibly targeting the same allele(s). Therefore, the anti-HLA antibody response can be highly complex and subtle, as is the accurate identification of pathogenic anti-HLA antibodies in human serum.

International audience; Human γδ T cells comprise a first line of defense through T-cell receptor (TCR) recognition of stressed cells. However, the molecular determinants and stress pathways involved in this recognition are largely unknown. Here we show that exposure of tumor cells to various stress situations led to tumor cell recognition by a Vγ8Vδ3 TCR. Using a strategy that we previously developed to identify antigenic ligands of γδ TCRs, annexin A2 was identified as the direct ligand of Vγ8Vδ3 TCR, and was found to be expressed on tumor cells upon the stress situations tested in a reactive oxygen species-dependent manner. Moreover, purified annexin A2 was able to stimulate the proliferation of a Vδ2 neg γδ T-cell subset within peripheral blood mononuclear cells and other annexin A2-specific Vδ2 neg γδ T-cell clones could be derived from peripheral blood mononuclear cells. We thus propose membrane exposure of annexin A2 as an oxidative stress signal for some Vδ2 neg γδ T cells that could be involved in an adaptive stress surveillance.

BACKGROUND Single antigen flow beads assays may overestimate sensitization because of the detection of supposedly irrelevant antibodies recognizing denatured class I human leukocyte antigens (HLAs). METHODS Sera of 323 HLA-sensitized kidney transplant candidates positive with a class I HLA single antigen flow beads assay were retested after acid treatment of the beads. Denatured HLA antibodies were identified according to ratio between the measured fluorescence intensity for treated and nontreated beads. T-lymphocyte flow cytometry crossmatches were performed to characterize the ability of these antibodies to recognize HLA on normal cells as a surrogate of their potential clinical relevance. Their impact on organ allocation was evaluated through a calculated panel reactive antibody. The utility of single antigen flow beads largely devoid of denatured HLA (iBeads) was also evaluated. RESULTS Denatured HLA antibodies were detected in 39% of the patients. They provided much less positive flow cytometry crossmatches than anti-native HLA antibodies (16% vs. 83%, P

Resume La defense face aux pathogenes et le controle de l’integrite de l’organisme sont les fonctions cardinales du systeme immunitaire. La volonte de comprendre les mecanismes qui sous-tendent ces deux fonctions a genere differentes theories depuis le debut du xx e siecle. Du concept soi/non-soi au modele « Danger », l’horizon immunologique s’est considerablement elargi. Nous proposons, dans cette mise au point, d’evaluer l’evolution des concepts de reponse anti-infectieuse et d’auto-immunite a travers l’evolution de ces differents modeles, en soulignant les limites et les avantages de chacun d’entre eux. Sur ces bases, nous proposons un modele « Danger augmente » integrant notamment le role des flores symbiotiques et du signal non-danger.

Screening studies using high-sensitivity and specificity markers indicate a prevalence of celiac disease of up to 1% in European and North-American populations. Celiac disease is a frequent condition that has become an important public health issue. Yet the majority of cases remain undiagnosed due to the polymorphism of its clinical manifestations. The new insight in the pathogenesis of celiac disease has lead to the development of new diagnostic tools. Early screening of symptomatic patients and pre-identified at-risk groups significantly improves the quality of life while reducing morbidity and mortality. However, prophylactic benefits of early diagnosis by assessing the general population have not been shown in any study. French and Northern American scientific societies have introduced serological testing in their newly revised strategies to diagnose celiac disease. Older markers judged insufficiently accurate like anti-gliadin and anti-reticulin antibodies have recently been withdrawn from the list of reimbursed medical expenses in France. Anti-endomysium and tissue transglutaminase IgA antibodies have proven to be at this day the most sensitive and specific markers for the diagnosis and follow-up of patients on gluten-free diet, at the exception of IgA-deficient patients. Assays testing for IgG antibodies are recommended upon IgA-deficiency. Although very accurate, a better standardisation of current assays may enable serological testing to replace in a near future histological confirmation brought by small bowel biopsies which remains today the gold standard test to diagnose celiac disease. Indeed, serological testing represents and attractive alternative as it is less invasive, less expansive, laboursaving and more objective in interpretation.

Celiac disease is an auto-immune enteropathy involving genetic factors. It is associated in almost all the patients, to specific susceptibility alleles encoding histocompatibility antigens (HLA for human leucocyte antigen), specifically certain variants of the HLA-DQ2, and the HLA-DQ8 HLA class II molecules. Its estimated prevalence is 1% in the european and north-american populations. However, although these alleles represent the main genetic factor for this disease, they do not explain it on their own, as they are expressed by up to 30% of the population. Recent immunological advances allowed identifying the immunodominant epitopes of gluten, to establish the role of tissue transglutaminase in the disease and to define at the atomic level the presentation of these antigens by the HLA-DQ molecule. It is noteworthy that the HLA susceptibility alleles only account for 40% of the whole genetic risk, and the challenge is now to explain the remaining 60%. Genome-wide association studies using the DNA arrays technology to screen single nucleotide polymorphisms to pinpoint candidate regions and genes, have started to provide answers, but contradictory results sometimes still persist. Most of the genes emerging as statistically significantly associated with celiac disease are involved in the immune response, and suggest that the situation is complex.

A higher chronic expansion of effector cytotoxic CD8(+)DR(+) T-lymphocytes has been reported in common variable immunodeficiency (CVID) patients with complications such as splenomegaly, autoimmune disease and/or granulomatous disease. In order to document the features associated with this T cell activation involving the CD8(+) T-compartment, we examined the diversity of the alpha/beta TCR repertoire of the patient's CD8(+) T-lymphocytes using the qualitative analysis of the CDR3 lengths (Immunoscope). Ten CIVD patients were enrolled in this study, four without complications (Group 1), six with complications (Group 2). All patients exhibited non-gaussian altered CDR3 length distributions, albeit to different extent within the different Vβ families. CVID patients with activated CD8(+) T-cells show a reduction of their TCR repertoire diversity which is more severe in patients with complications. Viral reactivations such as CMV are suspected to be part of the mechanisms underlying immunosenescence.

Low-grade, chronic inflammation has been associated with many diseases of aging, but the mechanisms responsible for producing this inflammation remain unclear. Inflammasomes can drive chronic inflammation in the context of an infectious disease or cellular stress, and they trigger the maturation of interleukin-1β (IL-1β). Here we find that the expression of specific inflammasome gene modules stratifies older individuals into two extremes: those with constitutive expression of IL-1β, nucleotide metabolism dysfunction, elevated oxidative stress, high rates of hypertension and arterial stiffness; and those without constitutive expression of IL-1β, who lack these characteristics. Adenine and N4-acetylcytidine, nucleotide-derived metabolites that are detectable in the blood of the former group, prime and activate the NLRC4 inflammasome, induce the production of IL-1β, activate platelets and neutrophils and elevate blood pressure in mice. In individuals over 85 years of age, the elevated expression of inflammasome gene modules was associated with all-cause mortality. Thus, targeting inflammasome components may ameliorate chronic inflammation and various other age-associated conditions.

International audience; Apoptosis has emerged as a fundamental process important in tissue homeostasis, immune response, and during development. CD95 (also known as Fas), a member of the tumor necrosis factor receptor (TNF-R) superfamily, has been initially cloned as a death receptor. Its cognate ligand, CD95L, is mainly found at the plasma membrane of activated T-lymphocytes and natural killer cells where it contributes to the elimination of transformed and infected cells. According to its implication in the immune homeostasis and immune surveillance, and since several malignant cells of various histological origins exhibit loss-of-function mutations, which cause resistance towards the CD95-mediated apoptotic signal, CD95 has been classified as a tumor suppressor gene. Nevertheless, this assumption has been recently challenged, as in certain pathophysiological contexts, CD95 engagement transmits non-apoptotic signals that promote inflammation, carcinogenesis or liver/peripheral nerve regeneration. The focus of this review is to discuss these apparent contradictions of the known function(s) of CD95.

International audience; The immune system eliminates infected or transformed cells through the activation of the death receptor CD95. CD95 engagement drives the recruitment of the adaptor protein Fas-associated death domain protein (FADD), which in turn aggregates and activates initiator caspases-8 and -10. The CD95-mediated apoptotic signal relies on the capacity to form the CD95/FADD/caspases complex termed the death-inducing signalling complex (DISC). Cells are classified according to the magnitude of DISC formation as either type I (efficient DISC formation) or type II (inefficient). CD95 localised to lipid rafts in type I cells, whereas the death receptor was excluded from these domains in type II cells. Here, we show that inhibition of both PI3K class IA and serine-threonine kinase Akt in type II cells promoted the redistribution of CD95 into lipid rafts, DISC formation and the initiation of the apoptotic signal. Strikingly, these molecular events took place independently of CD95L and the actin cytoskeleton. Overall, these findings highlight that the oncogenic PI3K/Akt signalling pathway participates in maintaining cells in a type II phenotype by excluding CD95 from lipid rafts.

Resume Le lupus erythemateux systemique (LES) se caracterise par une atteinte multiviscerale et, sur le plan biologique, par une reponse auto-immune dirigee contre des antigenes d’origine nucleaire. Les mecanismes physiopathologiques responsables du LES restent imparfaitement connus, mais de nombreux travaux recents ont souligne le role majeur joue par l’immunite innee. En effet, les Toll-like recepteurs (TLR), recepteurs situes au cœur de la resistance innee a la plupart des infections, sont aussi impliques dans des phenomenes inflammatoires aigus ou chroniques induits par des ligands endogenes. De nombreuses equipes ont ainsi demontre, in vitro, le role des TLR7 et TLR9 dans la reconnaissance de complexes immuns. La stimulation de ces recepteurs est alors responsable de l’activation de cellules de l’immunite et notamment des lymphocytes B et des cellules dendritiques et d’une production inappropriee de nombreuses cytokines connues pour avoir un role direct dans la pathogenie lupique. Ces resultats ont motive, dans differents modeles lupiques murins, des etudes d’inactivation ou de surexpression des genes codant pour les TLR ou pour des molecules impliquees dans les voies de signalisation de ces TLR. Ces travaux ont permis de confirmer l’importance du TLR7 et d’evoquer le role du TLR4 dans l’induction d’une reponse auto-immune agressive. En revanche, les donnees obtenues in vivo sur l’implication du TLR9 contredisent celles obtenues in vitro et suggerent un role protecteur. Enfin, chez l’homme, des etudes genetiques ont permis la mise en evidence de polymorphismes associes a un risque accru de developper un LES.

Resume Les facteurs de regulation de l’interferon (interferon regulatory factor [IRF]) ont initialement ete identifies dans le cadre de la recherche sur les interferons de type 1. Depuis, de nombreux travaux ont permis de demontrer leur role dans la regulation de la reponse immunitaire innee, du developpement des differentes cellules du systeme immunitaire et de l’oncogenese. Plusieurs etudes genetiques ont aussi permis d’identifier des variants genetiques, principalement d’IRF5, associes a un risque accru de developper des pathologies auto-immunes. Le role biologique des IRF dans ces pathologies a ete etudie in vitro mais aussi in vivo dans differents modeles murins. Nous resumons dans cette revue les roles des differents IRF et, notamment dans les voies de signalisation des Toll-like recepteurs. Nous rapportons aussi les differents travaux impliquant les IRF dans les pathologies dysimmunitaires.

SummaryBackgroundIt is documented that omalizumab treatment reduces the cell surface expression of immunoglobulin E high-affinity receptor (FcɛRI) on several cell types. This has not been investigated in patients with uncontrolled severe persistent allergic asthma.MethodsIn a double-blind, randomized, placebo-controlled study, patients with severe allergic asthma uncontrolled by high dose inhaled corticosteroids and long-acting β2-agonist received either omalizumab (n = 20) or placebo (n = 11) over 16 weeks at appropriate doses and frequencies. Baseline and end of study (week 16) FcɛRI expression on basophils and plasmacytoid dendritic cells was determined by flow cytometry for the primary endpoint. Secondary efficacy endpoints included asthma control and lung function as part of an initial investigation into the use of FcɛRI expression as a marker of response.ResultsIn the omalizumab group, and with respect to placebo, FcɛRI expression was significantly reduced at end of study on basophils (−82.6%, p

An increase in the number of blood gammadelta T cells follows cytomegalovirus (CMV) infection in kidney transplant recipients. These cells react against CMV-infected cells and tumor epithelial cells in vitro. We hypothesized that these CMV-induced gammadelta T cells play a protective role against cancer in kidney transplant recipients. We performed a longitudinal case-control study involving 18 recipients who developed cancer between 2 and 6 yr after transplantation and 45 recipients who did not. The median percentage of gammadelta T cells among total lymphocytes in patients with malignancies was significantly lower compared with that in control patients at 6, 12, and 18 mo before the diagnosis of cancer. Patients with a gammadelta T cell percentage of more than 4% were protected from cancer. An increase of the Vdelta2(neg) gammadelta T cell subset significantly associated with lower incidence of cancer only in recipients who experienced pre- or postgraft CMV infection. Finally, a retrospective follow-up of 131 recipients for 8 yr revealed that CMV-naive recipients had an approximately 5-fold higher risk of cancer compared with CMV-exposed patients. In summary, these results suggest a protective role of CMV exposure against cancer in kidney transplant recipients.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with multiorgan involvement characterized by an immune response against nuclear components. SLE patients experience a waxing and waning disease course and exhibit a wide array of clinical manifestations, reflecting the systemic nature of the disease. Environmental triggers such as viruses are likely to act in the context of susceptibility genes, including genes involved in antigen/immune complex clearance, lymphoid signalling, or apoptosis, among several others, explaining why the pathogenesis of this disease remains largely uncovered. The abnormal activation of the innate immunity is central to SLE physiopathology. Dendritic cells activation and unabated secretion of IFN-alpha are the key features of the disease through their involvement in the capture and the presentation of nuclear material to the autoreactive adaptive arm (T and B lymphocytes) leading to the subsequent production of anti-nuclear autoantibodies. In this line, numerous studies have demonstrated the prominent role of immune complexes deposition throughout the body which directly can induce inflammation and tissue damage. However, animal models and recent human studies support the concept that other effector pathways including cytotoxic T-lymphocytes could be involved in SLE pathogenesis through their ability to migrate and/or target specifically different tissues. The aim of this review is not to provide a comprehensive review of the SLE pathophysiology but rather to give an overview of the immunological abnormalities associated to SLE. The treatments that are currently used or that are in development to fight against abnormal immune response in SLE will be detailed. The genetics of SLE is not the scope of this review.

Background Kidney transplant recipients infected with cytomegalovirus (CMV) undergo a persistent gammadelta T cell expansion in their peripheral blood. The anti-CMV function of these cells was previously demonstrated by their ability to kill CMV-infected cells in vitro. Methods To gain insight into the role of gammadelta T cells within the antiviral immune network, we compared the expansion kinetics of these T cells with that of CMV pp65-specific CD8(+) alphabeta T cells in the peripheral blood of twenty-one kidney transplant recipients. Results Both the percentage and the absolute number of pp65-specific CD8(+) T cells and gammadelta T cells showed a concomitant increase and persistence in most of the kidney transplant recipients with CMV infection. Both cell subsets exhibited an effector/memory phenotype (CD28(-), CD27(-), and CD45RA(+)) that predominated for the entire follow-up period. Conclusions In conclusion, CMV-specific CD8(+) alphabeta T cells and gammadelta T cells share common expansion kinetics and a common effector phenotype, suggesting that these cell types act similarly in response to CMV infection.

gammadelta T cells recognize stress-induced autoantigens and contribute to immunity against infections and cancer. Our previous study revealed that Vdelta2-negative ((neg)) gammadelta T lymphocytes isolated from transplant recipients infected by cytomegalovirus (CMV) killed both CMV-infected cells and HT29 colon cancer cells in vitro. To investigate the antitumor effects of Vdelta2(neg) clones in vivo, we generated hypodermal HT29 tumors in immunodeficient mice. Concomitant injections of Vdelta2(neg)clones, in contrast to Vdelta2(+) cells, prevented the development of HT29 tumors. Vdelta2(neg) clones expressed chemokine C-C motif receptor 3 (CCR3) and migrated in vitro in response to chemokines secreted by HT29 cells, among which were the CCR3 ligands macrophage inflammatory protein-1delta and monocyte chemoattractant protein-4. More importantly, a systemic i.p. treatment with Vdelta2(neg) clones delayed the growth of HT29 s.c. tumors. The effect of in vivo gammadelta T-cell passive immunotherapy on tumor growth could be reverted by addition of a blocking anti-CCR3 antibody. gammadelta T-cell passive immunotherapy was dependent on the cytotoxic activity of the gammadelta effectors toward their targets because Vdelta2(neg) clones were not able to inhibit the growth of A431 hypodermal tumors. Our findings suggest that CMV-specific Vdelta2(neg) cells could target in vivo cancer cells, making them an attractive candidate for antitumor immunotherapy.

Background The short-term results of kidney transplantation are mainly attributed to the use of calcineurin inhibitors (CNI). However, opportunistic infections and cytomegalovirus (CMV) infections remain frequent and occur in the case of overimmunosuppression. Measurement of the biological effects of CNI could provide clues to identify overimmunosuppressed kidney transplant recipients (KTR) who would subsequently develop CMV infection. Methods Forty-one KTR given cyclosporine (n=18) or tacrolimus (n=23) were followed up every week during 1 month, then every month during 11 months, by measuring the patient's whole blood ability to inhibit interleukin-2 (IL-2) gene transcription and by measuring the patient's intracellular T-cell IL-2, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) production in response to polyclonal activation. Results Cytomegalovirus infection or disease occurred in 19 patients and was significantly associated with CMV serological status D+R- and D+R+ (HR=19.6 and 6.6, respectively, P=0.0001). Immunosuppressive treatment was associated with a long-lasting decrease of all cytokines produced by the patient's T-cells. However, none of these assays taken separately at any of the time points of the follow-up allowed to predict the occurrence of a subsequent CMV infection. We only observed a weak association between cumulative low levels of the percentage of TNF-alpha producing CD8+ T cells before CMV infection and its occurrence just afterwards (HR=1.39 for 1000 unit lower, P=0.04). However, this association did not remain significant after adjustment for CMV serological status. Conclusions This study suggests that immunological monitoring is not better than CNI whole blood levels for diagnosis of overimmunosuppression-induced CMV infection in KTR.

The ability of human γδ T cells to develop immunologic memory is still a matter of debate. We previously demonstrated the involvement of Vδ2− γδ T lymphocytes in the response of immunosuppressed organ recipients to cytomegalovirus (CMV). Here, we demonstrate their ability to mount an adaptive immune response to CMV in immunocompetent subjects. Vδ2− γδ T-cell peripheral blood numbers, repertoire restriction, and cytotoxicity against CMV-infected fibroblasts were markedly increased in CMV-seropositive, compared with CMV-seronegative, healthy persons. Whereas Vδ2− γδ T cells were found as naive cells in CMV− patients, they virtually all exhibited the cytotoxic effector/memory phenotype in CMV+ patients, which is also observed in transplanted patients challenged with CMV. This long-term complete remodeling of the Vδ2− γδ T-cell population by CMV predicts their ability to exhibit an adaptive anti-CMV immune response. Consistent with this, we observed that the secondary response to CMV was associated with a faster γδ T-cell expansion and a better resolution of infection than the primary response. In conclusion, the increased level of effector-memory Vδ2− γδ T cells in the peripheral blood is a specific signature of an adaptive immune response to CMV infection of both immunocompetent and immunosuppressed patients.

Background: Helicobacter pylori infection leads to different chronic diseases, suggesting that this bacterium can evade the host immune defense system. The ability to control lymphocyte proliferation may be a mechanism leading to the development of gastric pathologies. Our aim was to characterize the effects of mucosa-associated lymphoid tissue (MALT) associated H. pylori strains on lymphocyte proliferation. Materials and methods: We measured the in vitro proliferation of human lymphocytes originally from blood or tonsil samples in the presence or absence of viable bacteria or lysates. Results: We showed that MALT lymphoma-associated strains are not likely to be directly responsible for anarchical B-cell proliferation in vitro. On the other hand, proliferation of prestimulated T lymphocytes was abolished in vitro by the presence of all H. pylori strains, whether associated with MALT lymphoma or not. Conclusion: Inhibition of T-cell proliferation may be of major importance in the gastric colonization and in the persistence of the infection. Furthermore, this inhibition may favor anarchical B-cell proliferation in vivo and predispose the host to gastric MALT lymphoma, whereas MALT-associated H. pylori strains do not appear to possess a specific capability to directly stimulate B-lymphocyte proliferation.

La schizophrénie est associée à des troubles du fonctionnement mnésique et exécutif qui altèrent la capacité des patients à organiser leurs Activités de la Vie Quotidienne (AVQ). Afin d’améliorer leur autonomie et d’alléger la charge de leurs aidants, nous proposons de programmer des organiseurs en fonction des besoins spécifiques de chaque patient. Ces agendas électroniques permettent de rappeler au patient ses AVQ, et d’augmenter la communication avec l’aidant. Cette étude de convivialité vérifie que l’organiseur pressenti est fonctionnel. Malgré les problèmes techniques rencontrés, tous les participants ont été séduits par l’utilisation des organiseurs. Les aidants ont été convaincus que ces outils amélioreraient la qualité de vie des patients et constitueraient un complément de travail précieux. Les agendas seront améliorés d’après les commentaires des participants et testés dans une étude ultérieure., Mnesic and executive troubles elicited by schizophrenia decrease patient’s capacity to organise their Daily Living Activities (DLA). According to the needs of each patient, PDA (Personal Digital Assistant) were programmed in order to improve their autonomy and to reduce the load of their carers and relatives. These electronic diaries recall patient’s DLA and increase communication with carer. This conviviality study aims at verify that the material is operational. Despite some technical problems, all participants reported a great interest for the use of these diaries. Carers were convinced that these tools would represent an invaluable complement of work, and would improve the quality of life of their patients by bringing them more autonomy. According to the participants reports, PDA will be enhanced and tested in a subsequent study., La esquizofrenia está asociada a los trastornos del funcionamiento mnésico y de ejecución que alteran la capacidad de los pacientes para organizar sus Actividades de la Vida Cotidiana (AVQ). A fin de mejorar su autonomía y de aligerar la carga de sus ayudantes, proponemos programar los organizadores en función de las necesidades específicas de cada paciente. Estas agendas electrónicas permiten al paciente recordar sus AVQ y aumentar la comunicación con el ayudante. Este estudio de la facilidad de uso verifica que el organizador potencial sea funcional. A pesar de los problemas técnicos encontrados, todos los participantes fueron seducidos por el uso de los organizadores. Los ayudantes se convencieron de que estas herramientas mejoran la calidad de vida de los pacientes y constituirían un complemento de trabajo precioso. Las agendas serán mejoradas conforme a los comentarios de los participantes y se probarán en un estudio posterior., A esquizofrenia é associada a transtornos do funcionamento mnésico e executivo que alteram a capacidade dos pacientes em organizar suas Atividades da Vida Cotidiana (Activités de la Vie Quotidienne – AVQ). A fim de melhorar sua autonomia e tornar mais leve a carga de seus auxiliares, propomos programar agendas eletrônicas em função das necessidades específicas de cada paciente. Estes aparelhos permitem lembrar ao paciente suas AVQ, e aumentar a comunicação com o auxiliar. Este estudo de convivialidade verifica se a agenda pressentida é funcional. Apesar dos problemas técnicos que ocorreram, todos os participantes ficaram seduzidos pela utilização das agendas eletrônicas. Os auxiliares ficaram convencidos de que estas ferramentas melhoraram a qualidade de vida dos pacientes e constituiriam um complemento de trabalho precioso. As agendas serão modificadas, segundo os comentários dos participantes, e testadas em um estudo futuro.

Innate immunity is directly implicated in the pathophysiology of lupus through the dendritic cell system and the activation by immune complexes of some toll-like receptors (TLR). Interferon-alpha plays a key role in the pathophysiology of lupus and represents a promising target for immune therapy. Dendritic cells are activated and able to capture large quantities of nuclear antigen-containing bodies to stimulate specific adaptive immune response.

Objective Recent studies have revealed a potential implication of CD8+ T lymphocytes in the pathogenesis of systemic lupus erythematosus (SLE) through their ability to induce tissue damage. The aim of the present study was to analyze the localization of CD8+ cells in the kidneys of patients with class III and class IV lupus nephritis and to establish correlations with histologic, biologic, and clinical features of SLE. Methods Twenty-five consecutive SLE patients with class III or class IV lupus nephritis were enrolled. Phenotype analyses of blood lymphocytes and renal immunohistochemistry studies were performed. Results CD8+ T cells were the predominant kidney-infiltrating subset of cells. The mean ± SD numbers of CD8+ T cells and CD4+ T cells were 66.2 ± 65.2/mm2 and 19.3 ± 29.4/mm2, respectively. There was a significant correlation between the percentage of blood CD3+,CD8+,DR+ cells and the total number of renal CD8+ T cells (r = 0.42, P = 0.039). Renal CD8+ T cell infiltration correlated well with the renal activity index (r = 0.63, P = 0.0007) and with high serum creatinine levels (r = 0.75, P = 0.0001). This CD8+ T cell infiltrate, which was predominantly in the periglomerular area, was correlated with cellular crescents and Bowman's capsule rupture and was associated with a poor response after conventional induction therapy. Conclusion CD8+ T lymphocytes infiltrate the periglomerular area in patients with severe (class III and class IV) lupus nephritis and are linked to a poor outcome after induction therapy. These results reveal a new potential effector pathway operant in lupus nephritis.

Malaria induces potent activation and expansion of the Vγ9Vδ2 subpopulation of γδT cells, which inhibit the Plasmodium falciparum blood cycle through soluble cytotoxic mediators, abrogating merozoite invasion capacity. Intraerythrocytic stages efficiently trigger Vγ9Vδ2 T-cell activation and degranulation through poorly understood mechanisms. P. falciparum blood-stage extracts are known to contain phosphoantigens able to stimulate Vγ9Vδ2 T cells, but how these are presented by intact infected red blood cells (iRBCs) remains elusive. Here we show that, unlike activation by phosphoantigen-expressing cells, Vγ9Vδ2 T-cell activation by intact iRBCs is independent of butyrophilin expression by the iRBC, and contact with an intact iRBC is not required. Moreover, blood-stage culture supernatants proved to be as potent activators of Vγ9Vδ2 T cells as iRBCs. Bioactivity in the microenvironment is attributable to phosphoantigens, as it is dependent on the parasite DOXP pathway, on Vγ9Vδ2 TCR signaling, and on butyrophilin expression by Vγ9Vδ2 T cells. Kinetic studies showed that the phosphoantigens were released at the end of the intraerythrocytic cycle at the time of parasite egress. We document exquisite sensitivity of Vγ9Vδ2 T cells, which respond to a few thousand parasites. These data unravel a novel framework, whereby release of phosphoantigens into the extracellular milieu by sequestered parasites likely promotes activation of distant Vγ9Vδ2 T cells that in turn exert remote antiparasitic functions.

International audience; Objectives: Innate immune system alterations, including dendritic cell loss, have been reproducibly observed in patients with septic shock and correlated to adverse outcomes or nosocomial infections. The goal of this study is to better understand the mechanisms behind this observation in order to better assess septic shock pathogenesis.Design: Prospective, controlled experimental study. Setting: Research laboratory at an academic medical center. Subjects: The study enrolled 71 patients, 49 with septic shock and 22 with cardiogenic shock. Seventeen healthy controls served as reference. In vitro monocyte-derived dendritic cells were generated from healthy volunteers. Interventions: Sera were assessed for their ability to promote in vitro dendritic cell death through flow cytometry detection in each group of patients. The percentage of apoptotic or necrotic dendritic cells was evaluated by annexin-V and propidium iodide staining. Measurements and Main Results: We observed that only patients with septic shock and not patients with pure cardiogenic shock were characterized by a rapid and profound loss of circulating dendritic cells. In vitro analysis revealed that sera from patients with septic shock induced higher dendritic cell death compared to normal sera or cardiogenic shock (p < 0.005). Sera from surviving patients induced dendritic cell death through a caspase-dependent apoptotic pathway, whereas sera from nonsurviving patients induced dendritic cell-regulated necrosis. Dendritic cell necrosis was not due to necroptosis but was dependent of the presence of circulating histone. The toxicity of histones toward dendritic cell could be prevented by recombinant human activated protein C. Finally, we observed a direct correlation between the levels of circulating histones in patients and the ability of the sera to promote dendritic cell-regulated necrosis. Conclusions: The study demonstrates a differential mechanism of dendritic cell death in patients with septic shock that is dependent on the severity of the disease.

OBJECTIVES We studied the link between T-cell activation, differentiation and senescence phenotypes and non-AIDS-related comorbidities in HIV-suppressed patients. DESIGN Patients included in the ANRS CO3 Aquitaine Cohort were consecutively enrolled in this cross-sectional study between October 2011 and May 2013 called Chronic Immune Activation and Senescence (CIADIS) study. METHODS We summarized immune markers [CD4 and CD8 activation (DR), differentiation (naive and terminally differentiated memory T cells), and senescence (CD57CD28)] in a weighted immune score by principal component analysis called CIADIS. Previously described Veterans Aging Cohort Study (VACS) index and immune risk profile (IRP) scores were calculated. We used adjusted logistic regression to assess the association between the CIADIS score and the presence of at least three non-AIDS-defining comorbidities. RESULTS Of 876 patients with an undetectable viral load, 73.4% were men and median age was 50.5 years [interquartile range (IQR) 44.7-56.7 years]. Median CD4 T-cell count was 579/μl (IQR 429-759 cells/μl), and median duration of HIV viral suppression was 5.3 years (IQR 2.3-8.7). The weighted CIADIS score was associated with at least three comorbidities (odds ratio 1.3 for 1 SD more, 95% confidence interval 1.0, 1.6) independently of age, sex, AIDS stage, and the Veterans Aging Cohort Study score. The CIADIS and the immune risk profile scores were significantly associated with at least three comorbidities in adjusted models restricted to patients younger than 60 years. None of the tested scores were associated with at least three comorbidities in patients older than 60 years. CONCLUSIONS The weighted CIADIS score based on activation, senescence, and differentiation markers might help physicians identifying patients at a higher risk for non-AIDS-related comorbidities.