The metabolic checkpoint kinase mTOR is essential for IL-15 signaling during the development and activation of NK cells.

Interleukin 15 (IL-15) controls both the homeostasis and the peripheral activation of natural killer (NK) cells. The molecular basis for this duality of action remains unknown. Here we found that the metabolic checkpoint kinase mTOR was activated and boosted bioenergetic metabolism after exposure of NK cells to high concentrations of IL-15, whereas low doses of IL-15 triggered only phosphorylation of the transcription factor STAT5. mTOR stimulated the growth and nutrient uptake of NK cells and positively fed back on the receptor for IL-15. This process was essential for sustaining NK cell proliferation during development and the acquisition of cytolytic potential during inflammation or viral infection. The mTORC1 inhibitor rapamycin inhibited NK cell cytotoxicity both in mice and humans; this probably contributes to the immunosuppressive activity of this drug in different clinical settings.

USE OF A THRESHOLD OF INTERLEUKIN-10 AND IL-10/IL-6 RATIO IN OCULAR SAMPLES FOR THE SCREENING OF VITREORETINAL LYMPHOMA.

PURPOSE: To determine a threshold for interleukin (IL)-10 and IL-10/IL-6 ratio in the aqueous humor (AH) and the vitreous for the screening of vitreoretinal lymphoma (VRL). METHODS: One hundred nineteen patients for whom IL-10 and IL-6 in the AH and/or vitreous had been measured were included: 16 patients with a final diagnosis of VRL and 103 patients with final diagnosis of uveitis. Groups were compared according to IL-10 and IL-6 levels and demographic data. RESULTS: In patients with VRL (Group 1), mean IL-10 values were 5,636 pg/mL, and in patients with uveitis (Group 2), 6.7 pg/mL in the vitreous and 190 pg/mL in Group 1 and 8.6 pg/mL in the AH. In Group 1, the mean IL-10/IL-6 ratio was 29.02 in the vitreous and 10.9 in the AH; in Group 2, ratio was 0.1 in both humors. These values were significantly different between patients with VRL and with uveitis (P < 0.001). A cutoff of 65 pg/mL and 30 pg/mL IL-10 in the vitreous and AH, respectively, was associated with sensitivity of 93% and 78%, respectively, and specificity of 100% and 97%, respectively. A ratio higher than 1 in the vitreous had sensitivity of 93% and specificity of 100%. CONCLUSION: Vitreoretinal lymphoma diagnosis is difficult, and tools like interleukin measurements in AH and vitreous can make it easier. The use of a cutoff for IL-10 and IL-10/IL-6 ratio could allow for an earlier diagnosis that may improve prognosis.

Alteration of Natural Killer cell phenotype and function in obese individuals.

Obesity is associated with increased cancer rates and higher susceptibility to infections. The adipose tissue of obese individuals is inflammatory and may negatively impact on innate and adaptive immunity in a systemic way. Here, we explored the phenotype and function of peripheral Natural Killer (NK) cells of patients in correlation with their body mass index (BMI). We found that high BMI was associated with an increased activation status of peripheral NK cells, as measured by surface levels of CD69 and levels of granzyme-B. However, these activated NK cells had an impaired capacity to degranulate or to produce cytokines/chemokines when exposed to tumor cell lines deficient in MHC-I expression or coated with antibodies. This suggests that chronic stimulation of NK cells during obesity may lead to their incapacity to respond normally and eliminate target cells, which could contribute to the greater susceptibility of obese individuals to develop cancers or infectious diseases.

PRKDC mutations associated with immunodeficiency, granuloma, and autoimmune regulator-dependent autoimmunity.

BACKGROUND: PRKDC encodes for DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a kinase that forms part of a complex (DNA-dependent protein kinase [DNA-PK]) crucial for DNA double-strand break repair and V(D)J recombination. In mice DNA-PK also interacts with the transcription factor autoimmune regulator (AIRE) to promote central T-cell tolerance. OBJECTIVE: We sought to understand the causes of an inflammatory disease with granuloma and autoimmunity associated with decreasing T- and B-cell counts over time that had been diagnosed in 2 unrelated patients. METHODS: Genetic, molecular, and functional analyses were performed to characterize an inflammatory disease evocative of a combined immunodeficiency. RESULTS: We identified PRKDC mutations in both patients. These patients exhibited a defect in DNA double-strand break repair and V(D)J recombination. Whole-blood mRNA analysis revealed a strong interferon signature. On activation, memory T cells displayed a skewed cytokine response typical of TH2 and TH1 but not TH17. Moreover, mutated DNA-PKcs did not promote AIRE-dependent transcription of peripheral tissue antigens in vitro. The latter defect correlated in vivo with production of anti-calcium-sensing receptor autoantibodies, which are typically found in AIRE-deficient patients. In addition, 9 months after bone marrow transplantation, patient 1 had Hashimoto thyroiditis, suggesting that organ-specific autoimmunity might be linked to nonhematopoietic cells, such as AIRE-expressing thymic epithelial cells. CONCLUSION: Deficiency of DNA-PKcs, a key AIRE partner, can present as an inflammatory disease with organ-specific autoimmunity, suggesting a role for DNA-PKcs in regulating autoimmune responses and maintaining AIRE-dependent tolerance in human subjects.

Improving the cytological diagnosis of intraocular lymphoma from vitreous fluid.

AIMS: To improve the cytological diagnosis of retinal lymphoma on vitreous fluid using improved cell collection and systematic analyses. METHODS AND RESULTS: Since October 2010, we have developed and optimized in our department a method with which to perform the diagnosis of retinal lymphoma. The vitreous sample was collected in a tube containing RPMI-1640 medium, decomplemented fetal bovine serum, and gentamicin. The transport and technical steps were performed at 4°C. Systematically, cytological examination with May-Grünwald-Giemsa staining and immunocytochemistry (mainly anti-CD3, anti-CD20 and anti-CD68 antibodies) were performed on cytospins. Whenever possible, determination of B-cell clonality, flow cytometry and determination of the interleukin (IL)-10/IL-6 ratio were performed. From October 2010 to June 2013, with this optimized protocol, 38 vitreous cytological samples from 32 patients were analysed, and a final diagnosis was possible, avoiding a biopsy, in all cases except one. CONCLUSION: The preservation of vitreous fluid cells on culture medium led to the diagnosis of retinal lymphoma in 10 of 12 cases, and exclusion of this diagnosis in 26 cases. This protocol may be applied even when the delay in shipping from the surgery to the pathology departments exceeds 1 h.

The basophil activation test: a sensitive test in the diagnosis of allergic immediate hypersensitivity to pristinamycin.

Immediate hypersensitivity (IHS) reactions to macrolides and to macrolide-derived antibiotics like pristinamycin are uncommon. In this context, there is little data available to appreciate the true value of biological tools regarding the diagnosis of immediate allergy to pristinamycin. Here we assess the clinical usefulness of the basophil activation test (BAT) to differentiate allergic from nonallergic IHS to pristinamycin. Thirty-six patients were tested with skin tests as the gold standard and BAT. The BAT achieved a sensitivity of 76% and a specificity of 100%, implying an absence of false positive results. Multicenter studies remain to be performed to better define the sensitivity, specificity and interlaboratory variation of BAT in the diagnosis of allergy to pristinamycin and macrolides.

Early diagnosis of celiac disease in IgA deficient children: contribution of a point-of-care test.

BACKGROUND: The serological diagnosis of celiac disease (CD) often relies on the presence of anti-tissue transglutaminase (tTG) IgA autoantibodies. Patients suffering from selective IgA deficiency (IgAD) are often not aware of their IgA deficiency and are tested as CD negative, delaying considerably the diagnosis. The detection of IgG against deamidated gliadin peptides (DGP) has high specificity and better sensitivity than IgG anti-tTG. A multi-analytic lateral-flow immunochromatographic assay (CD-LFIA) based on the detection of IgA and IgG anti-DGP and total IgA was shown to have a good diagnostic accuracy for CD. The aim of this study was to evaluate the clinical accuracy of its use in children suffering from IgAD. METHODS: 45 IgAD children ranging from 1.1 to 17.4 years and suspected of CD or having high CD risk factors were referred from outpatient clinics located in the area of Rhone-Alpes (France) to the Hospices Civils de Lyon, Paediatric Hospital-Gastroenterology-Hepatology- Nutrition Department for further CD investigations. The CD investigations, including the sample collection, were performed within the Paediatric Hospital-Gastroenterology-Hepatology- Nutrition Department, and the serological testing was performed at the Lyon-Sud Hospital-Immunology Laboratory. The diagnosis of CD was based on IgG anti-tTG serology, biopsy results and patient follow-up. The serum samples were retrospectively tested on the CD-LFIA test. RESULTS: A total of eight (8) patients were diagnosed as new CD. All were correctly identified by the CD-LFIA. The test yielded four (4) false positive results. Two patients with positive IgG anti-tTG were negative on CD-LFIA, but were classified as CD negative based on biopsy results and patient follow-up. The remaining 33 patients were found negative by both methods. The specificity and sensitivity of CD-LFIA was of 89.2% [74.6-97.0] and of 100% [63.1-100] respectively. The negative predictive value (NPV) was of 100% [89.4-100], and the Likelihood Ratio for Negative Test (LR-) was of 0 [0.0-0.91]. CONCLUSIONS: CD-LFIA is a useful, non-invasive and rapid tool to rule out CD in primary care paediatric patients having CD-related symptoms and IgAD. Patients having a positive CD-LFIA result could be then readily directed to secondary care setting for further evaluation by standard serology and biopsy.

Natural killer cells and T cells induce different types of skin reactions during recall responses to haptens.

The role of T cells in contact hypersensitivity (CHS) to haptens has been well described. However, recent reports demonstrated that CHS-like reactions to experimental haptens could be induced in mice deficient in T cells and B cells, as a result of adaptive-like features of NK cells. Here, we compared hapten-specific inflammatory reactions induced by memory T cells or NK cells. Classical CHS protocols were applied to WT or T- and B-cell deficient mice. Adoptive transfers of hapten-specific T cells and NK cells were also performed. Liver NK cells from hapten-primed mice induced specific recall responses to haptens upon transfer in CD3ε-deficient mice, thus confirming the existence of "memory" NK cells in the liver. We investigated the nature of the inflammation generated in these transfer conditions and found that hapten-induced skin inflammation mediated by CD8(+) T cells or "memory" NK cells are different. Indeed, ear swelling induced by memory NK cells was transient and not associated with cellular infiltrate and inflammation markers, characteristic for T-cell-mediated responses. Thus, NK cells and T cells mediate distinct forms of skin inflammation. NK cell-mediated pathogenesis does not rely on cellular infiltrate and could be involved in atypical forms of adverse drug reactions.

Intraperitoneal cytokine level in patients with peritoneal surface malignancies. A study of the RENAPE (French Network for Rare Peritoneal Malignancies).

BACKGROUND: Prognosis of peritoneal surface malignancies is influenced by the adequacy of surgical and chemotherapeutic treatment and by tumor spread at the time of diagnosis. By promoting morphological changes in the mesothelium, inflammatory cytokines reflect tumor biology and could be evaluated as biomarkers. Our objective was to evaluate intraperitoneal levels of IL-6, IL-8, IL-10, TNF-alpha, and sICAM in patients with pseudomyxoma peritonei and peritoneal mesothelioma. METHODS: Serum and peritoneal fluid samples were prospectively collected in patients managed for peritoneal surface malignancies including pseudomyxoma peritonei (PMP), mesotheliomas, and other rare primitive peritoneal cancers (cancer group) and patients who underwent intraperitoneal laparoscopic surgical procedures for benign diseases (noncancer group). Samples were analyzed for IL-6, IL-8, IL-10, TNF-alpha, and sICAM concentrations. Correlations were assessed with tumor spread related clinical scores. RESULTS: In both patient groups, intraperitoneal cytokine levels were higher than serum levels. Cancer patients had significantly higher intraperitoneal cytokine levels than noncancer patients. Peritoneal levels tended to increase in cancer patients with free tumor cells in peritoneal fluid. They were significantly higher in patients with tumor implants ≥2 cm and/or patients with peritoneal carcinomatosis index (PCI) >19. Furthermore, patients with malignant pseudomyxoma peritonei (grades II and III) had higher levels than patients with nonmalignant disease (grade I). CONCLUSIONS: Assessment of intraperitoneal IL-6, IL-8, IL-10, TNF-alpha, and sICAM levels can be performed in patients with peritoneal surface malignancies. They can be considered as both diagnostic and prognostic biomarkers that could be used as useful adjuncts for therapeutic decision making.

Negativity of the basophil activation test in quinolone hypersensitivity: a breakthrough for provocation test decision-making.

BACKGROUND: Quinolone hypersensitivity reactions are being more frequently reported. Skin tests in investigations of patients are known to not be fully reliable. The provocation test thus remains the gold standard in the definitive diagnosis of allergy, despite the risks involved. The aim of this study was to evaluate basophil activation tests (BATs) in the diagnosis of immediate-type reactions to quinolones. METHODS: Thirty-four patients who presented an immediate-type hypersensivity reaction less than an hour after quinolone administration were studied. The allergologic workup of these patients consisted of a careful clinical history, a skin test and a BAT with the culprit quinolone. If not contraindicated, and in the case of high probability of a nonallergic reaction, provocation tests were performed to assess the nonimmunologic nature of the hypersensitivity. RESULTS: Among the 34 patients studied, 17 (50%) presented a negative BAT to the suspected quinolone, while the other 17 (50%) patients presented a positive BAT for quinolone at the time of their reaction. Among the 17 patients with negative BATs, 15 (2 of whom had had positive skin tests) had quinolone successfully reintroduced. CONCLUSIONS: Our report suggests that the BAT, if negative for the culprit quinolone, is a valuable tool in the decision whether or not to perform provocation tests in patients with a history of immediate-type reaction to quinolones, in order to exclude an allergic reaction.

[Homeostasis of natural killer cells]. / Homéostasie des cellules natural killer.

Natural killer (NK) cells are important players of innate immunity, dedicated to the host defense against viruses and also involved in the immune surveillance of tumors. NK cells are widely distributed in the body and their number may increase locally during infection. They develop mainly in the bone marrow and perhaps in other lymphoid organs. They are constantly renewed, with a half-life of about 17 days at the periphery. In this article, we review the factors that regulate the homeostasis of NK cells including their development, differentiation, export to the periphery, their turnover, their homeostatic or antigen-induced proliferation and their survival before or after activation. In addition, we discuss the homeostasis of recently described so-called "memory" NK cells.

Hypersensitivity transfusion reactions to fresh frozen plasma: a retrospective analysis of the French hemovigilance network.

Few data are currently available on hypersensitivity transfusion reactions (HTRs) after exposure to fresh frozen plasma (FFP). Between 2000 and 2018, three different FFP production strategies have been used in France, leading to the concomitant use of different types of FFP. The objective of this study was to describe the rate of FFP-related HTRs and to assess the relative risk of each type of FFP. HTR following FFP transfusion between 2000 and 2018 were retrospectively extracted from the national hemovigilance database of the French National Agency for Medicines and Health Products Safety (ANSM). Temporal evolution of the incidence of reactions was modeled using logistic regression. During the study period, the overall rate of FFP-related HTRs was 52.0 (95% CI 50.2-53.9) reactions per 100,000 units of FFP issued. The rate of FFP-related HTRs progressively increased over the study period, from 28.7 (95% CI 22.8-36.0) in 2000 to 88.9 (78.8-100.3) reactions per 100,000 units of FFP issued in 2018 (OR 1.08 [1.07 - 1.09], P < .001), whereas the rate of other types of adverse transfusion reactions (ATRs) decreased. Between 2000 and 2014, its period of use, Solvent-Detergent-treated Apheresis FFP (SD-APH) was associated with the lowest risk of HTR. Our results indicate that although the rate of HTRs to FFP is low in France, the risk of having such a reaction has steadily increased between 2000 and 2018. A declarative bias is unlikely as the rate of other type of FFP-related ATRs decreased over the same period. The risk of HTRs to FFP is suggested to differ according to the processing of the FFP with a lower risk for SD-APH.

Relationships of circulating CD4+ T cell subsets and cytokines with the risk of relapse in patients with Crohn's disease.

Background and aims: We aimed to analyze circulating CD4+ T cell subsets and cytokines during the course of Crohn's disease (CD). Methods and results: CD4+ T cell subsets, ultrasensitive C-reactive protein (usCRP), and various serum cytokines (IL-6, IL-8, IL-10, IL-13, IL-17A, IL-23, TNFα, IFNγ, and TGFß) were prospectively monitored every 3 months for 1 year, using multicolor flow cytometry and an ultrasensitive Erenna method in CD patients in remission at inclusion. Relapse occurred in 35 out of the 113 consecutive patients (31%). For patients in remission within 4 months prior to relapse and at the time of relapse, there was no significant difference in Th1, Th17, Treg, and double-positive CD4+ T cell subsets co-expressing either IFNγ and FOXP3, IL-17A and FOXP3, or IFNγ and IL-17A. On the contrary, in patients who remained in remission, the mean frequency and number of double-positive IL-17A+FOXP3+ CD4+ T cells and the level of usCRP were significantly higher (p ≤ 0.01) 1 to 4 months prior to relapse. At the time of relapse, only the IL-6 and usCRP levels were significantly higher (p ≤ 0.001) compared with those patients in remission. On multivariate analysis, a high number of double-positive IL-17A+FOXP3+ CD4+ T cells (≥1.4 cells/mm3) and elevated serum usCRP (≥3.44 mg/L) were two independent factors associated with risk of relapse. Conclusions: Detection of circulating double-positive FOXP3+IL-17A+ CD4+ T cell subsets supports that T cell plasticity may reflect the inflammatory context of Crohn's disease. Whether this subset contributes to the pathogenesis of CD relapse needs further studies.

A multicentre, randomised, double-blind, placebo-controlled trial with the interleukin-1 receptor antagonist anakinra in patients with systemic-onset juvenile idiopathic arthritis (ANAJIS trial).

OBJECTIVES: To assess the efficacy of the interleukin 1 receptor antagonist anakinra in systemic-onset juvenile idiopathic arthritis (SJIA). METHODS: A multicentre, randomised, double-blind, placebo-controlled trial was conducted. The primary objective was to compare the efficacy of a 1-month treatment with anakinra (2 mg/kg subcutaneous daily, maximum 100 mg) with a placebo between two groups each with 12 patients with SJIA. Response was defined by a 30% improvement of the paediatric American College of Rheumatology criteria for JIA, resolution of systemic symptoms and a decrease of at least 50% of both C-reactive protein and erythrocyte sedimentation rate compared with baseline. After month 1 (M1), patients taking placebo were switched to anakinra. Secondary objectives included tolerance and efficacy assessment for 12 months, and analyses of treatment effect on blood gene expression profiling. RESULTS: At M1, 8/12 responders were receiving anakinra and 1 responder receiving placebo (p=0.003). Ten patients from the placebo group switched to anakinra; nine were responders at M2. Between M1 and M12, six patients stopped treatment owing to an adverse event (n=2), lack of efficacy (n=2) or a disease flare (n=2). Blood gene expression profiling at enrollment and at 6 months' follow-up showed one set of dysregulated genes that reverted to normal values in the clinical responders and a different set, including interferon (IFN)-inducible genes, that was induced by anakinra. CONCLUSIONS: Anakinra treatment is effective in SJIA, at least in the short term. It is associated with normalisation of blood gene expression profiles in clinical responders and induces a de novo IFN signature. TRIAL REGISTRATION NUMBER: NCT00339157.

Insights into the Allergenic Potential of the Edible Yellow Mealworm (Tenebrio molitor).

The edible yellow mealworm (Tenebrio molitor), contains an extremely diverse panel of soluble proteins, including proteins with structural functions such as muscle proteins, as well as proteins involved in metabolic functions such as enzymes. Most of these proteins display a more or less pronounced allergenic character toward previously sensitized people, especially people allergic to shrimps and other shellfish. A mass spectrometry approach following the separation of a mealworm protein, extracted by sodiumdodecyl sulfate-polyacrylamide gel electrophoresis, allowed us to identify up to 106 distinct protein fractions including molecules with structural and functional functions, susceptible to developing an allergenic potential due to the possibility of immunoglobulin E-binding cross-reactions with their counterparts occurring in shellfish. In this respect, most of the sera from people allergic to shrimps reacted with the mealworm protein extract in Western blot experiments. Moreover, the potential mealworm allergens triggered the in vitro degranulation of rat leukemic basophils transfected with the human high-affinity IgE receptor (FcεRI), upon sensitization by the IgE-containing sera from people allergic to shrimps and other shellfish foods. Owing to the large repertoire of IgE-binding cross-reacting allergens the yellow mealworm shares with other phylogenetically-related groups of arthropods, it would seem prudent to inform the consumers, especially those allergic to shellfish, by appropriate labeling on edible mealworm packages about the potential risk of developing an allergic reaction.

Induction of high expression of CCR7 and high production of IL-12 in human monocyte-derived dendritic cells by a new bacterial component: LCOS 1013.

Dendritic cells (DCs) are the most potent antigen presenting cells of the immune system as they can act as initiators, stimulators and regulators of the immune response. Human DCs are most commonly generated for clinical use by in vitro differentiation of monocytes with exogenous cytokines. Here, we investigate the effect of LCOS 1013 on the production of mature Mo-DCs. LCOS 1013 is a new bacterial component from walls of gram(+)Klebsellia pneumoniae bacteria that contain some OmpA glycoproteins. Purified peripheral blood monocytes were cultured for 6 days with IL-4 and GM-CSF in order to obtain immature dendritic cells (Im-MoDCs). On day six, Im-MoDCs were matured with either LCOS 1013, TNF alpha, LPS or CD40-Ligand. LCOS 1013 matured Mo-DCs (LCO-DCs) showed a higher expression of DC-LAMP, CD80, CD83, CD54 and CD40 than TNF alpha, LPS and CD40L matured Mo-DCs. Interestingly, LCO-DCs exhibited high expression of full competent CCR7 and high secretion of IL-12 during their maturation. Functionally, LCO-DCs have equivalent potency to trigger mixed leukocyte reaction and antigen-specific reaction and polarize immune response towards Th1 way. Moreover, we found that LCOS 1013 activates DCs through TLR2. LCOS 1013 represents an attractive therapeutic maturation agent of DCs allowing the production of Mo-DCs with high capacity to migrate and to induced Th1 immune responses.

Carbonic anhydrase III: a new target for autoantibodies in autoimmune diseases.

The objective of this study was to identify new autoantibodies that could be useful for the diagnosis of rheumatoid arthritis (RA) using immunoblotting on synovial membrane proteins which represent the best source of candidate RA autoantigens. A new target protein with a molecular weight of 26 kDa was found to be recognized by autoantibodies in RA sera and was identified using MALDI-TOF mass spectrometry and second-dimension electrophoresis as carbonic anhydrase III (CAIII). Three similar protein spots at 26 kDa were recognized by both human sera and monoclonal antibody (mAb) directed against CAIII on immunoblotting using the human recombinant CAIII. Interestingly, CAIII expression within the synovial membrane was not observed in non-RA patients and was differentially expressed among RA patients. The sensitivity of these new autoantibodies for RA, using an immunoenzymatic technique, was 17%. Specificity was high when comparing non-autoimmune diseases (100%), while it was found to be weak (67%) when comparing some other autoimmune diseases, and particularly systemic lupus erythematosus (SLE). In conclusion, this study demonstrates that these new autoantibodies against CAIII are not restricted to RA. However the expression of CAIII in the synovial membrane of RA warrants further investigation of the pathophysiological relevance of this finding.

A new target for autoantibodies in patients with rheumatoid arthritis.

Early treatment of rheumatoid arthritis (RA) with disease-modifying antirheumatic drugs can achieve a better disease outcome and reduce the severity of joint damage. The presence of autoantibodies in patient sera can precede onset of the disease and thus be predictive of the development of RA. To date, known autoantibodies in RA are positive in only 50-60% of RA patients at onset of disease and even less before the onset of any RA symptom. The aim of this study was to identify new antibodies that could be useful for the diagnosis of RA using synovial membrane proteins, which represent the best source of candidate RA autoantigens. The humoral reactivity of sera from RA patients was explored using immunoblotting on extracted proteins obtained from synovial membranes from RA after synovectomy or arthroplasty. A new target protein with a molecular weight of 26 kDa was found to be recognized by autoantibodies in RA sera. This protein was identified using MALDI-TOF mass spectrometry and two-dimensional electrophoresis as carbonic anhydrase III with a high level of confidence. In conclusion, this study demonstrates new autoantibodies in RA patients that are directed against carbonic anhydrase III. The sensitivity and specificity of these new autoantibodies for RA have to be further evaluated.