Children with Down syndrome (DS) suffer from recurrent respiratory infections, which represent the leading cause of mortality during childhood. This susceptibility to infections is usually considered ...multifactorial and related to both impaired immune function and non-immunological factors. Infections are also one of the top causes of death in DS at adulthood. DS is considered an immunodeficiency with syndromic features by some researchers because of this high rate of infection and the immunological characteristics observed in children with DS. Little is known about the immune status of adult patients. Herein, we report the clinical and immune phenotype of 44 adults with DS, correlated with their infectious history. We observed that these adults had an aberrant lymphocyte phenotype with decreased naïve/memory T cell ratios and reduced numbers of switched memory B cells. The lower incidence of infectious events at adulthood distinguish DS from other inborn errors of immunity. Primary immunodeficiency-related features in DS could explain the increased risk of developing autoimmunity, malignancies, and infections. During adulthood, this immune dysfunction may be compensated for in mid-life, and infection-related mortality observed in older patients might be favored by multiple factors such as neurological impairment or nosocomial antigen exposure.
www.ClinicalTrials.gov, identifier NCT01663675 (August 13, 2012).
An overall response assay OVA, based on a 23-valent pneumococcal polysaccharide vaccine (PPV23) is widely used to screen for anti-pneumococcal antibodies. Given the heterogeneity of response from one ...polysaccharide (PS) to another, a World Health Organization-standardized serotype-specific enzyme-linked immunosorbent assay (SSA) is considered to be the only reliable method for testing anti-PS antibody responses in individuals with suspected primary immunodeficiencies (PIDs).
To evaluate the OVA relative to the reference SSA.
Serum samples of adult patients referred for a suspected PID were collected before and then 4-8 weeks after immunization with PPV23. The anti-pneumococcal response was systematically assessed with an SSA (7-16 serotypes) and interpreted according to the American Academy of Asthma, Allergy and Immunology's current guidelines. We used receiver operating characteristic curves and agreement indices to assess the OVA's diagnostic value in a first cohort. In order to validate these findings, a second (validation) cohort was then prospectively included.
Sixty-two adult patients were included, and 42 (67.7%) were defined as poor responders according to the SSA. Only the post-immunization titer in the OVA was able to correctly identify poor responders; a titer below 110 mg/L gave a positive predictive value of 100% identifying 24 (57.1%) of the 42 poor responders, and similar levels of diagnostic performance were observed in the validation cohort. The pre-vaccination antibody titer, the post/pre-vaccination antibody titer ratio and a post-vaccination titer above 110 mg/L in the OVA were not predictive of the response in the SSA.
A post-vaccination antibody titer below 110 mg/L in the OVA was constantly associated with a poor PPV23 response using the SSA. In all other cases, SSA is the only reliable method for assessing diagnostic vaccination with PPV23.
Graft-versus Host Disease (GvHD) is a major complication of hematopoietic stem cell transplant. GvHD is characterized by the chronic activation of immune cells leading to the development of systemic ...inflammation, autoimmunity, fibrosis and eventually death. Arsenic trioxide (ATO) is a therapeutic agent under clinical trial for the treatment of patients with systemic lupus erythematosus (SLE) and chronic GvHD (cGvHD). This therapy is admittedly rather safe although adverse effects can occur and may necessitate short interruptions of the treatment. The aim of this study was to combine ATO with a divalent cation, to generate a Fenton or Fenton-like reaction in order to potentiate the deletion of activated immune cells through the reactive oxygen species (ROS)-mediated effects of ATO in a mouse model, and thereby enabling the use of lower and safer ATO concentrations to treat patients with cGvHD.
In vitro
, among the various combinations of divalent cations tested, we observed that the combination of ATO and CuCl
2
(copper chloride) induced a high level of oxidative stress in HL-60 and A20 cells. In addition, this co-treatment also decreased the proliferation of CD4
+
T lymphocytes during a mixed lymphocyte reaction (MLR).
In vivo
, in a cGvHD mouse model, daily injections of ATO 2.5 µg/g + CuCl
2
0.5 µg/g induce a decrease in lymphocyte activation and fibrosis that was equivalent to that induced by ATO 5 µg/g. Our results show that the addition of CuCl
2
improved the effects of ATO and significantly limited the development of the disease. This co-treatment could be a real benefit in human patients to substantially decrease the known ATO side effects and optimize ATO treatment in pathologies characterized by activated cells sensitive to an increase in oxidative stress.
Endometriosis is a condition characterized by increased oxidative stress and chronic inflammation, which can be treated with progestins and other progesterone receptor ligands. However, some patients ...are refractory to this treatment and the reason is uncertain. Here we investigated the effects of the selective progesterone receptor modulator ulipristal acetate (UPA) on proliferation, reactive oxygen species (ROS), and proinflammatory cytokine production by endometriotic cells and endometrial cells from women with histologically proven endometriosis (n = 22) and endometriosis-free controls (n = 6). Epithelial and stromal cells were isolated and treated in triplicate for 24 h with 1 μM, 10 μM, or 100 μM UPA. Cells were tested for proliferation and ROS production, while cell supernatants were assayed for interleukin (IL)-6, C-C motif chemokine ligand 2 (CCL2), and tumor necrosis factor (TNF)-α concentrations. Proliferation, ROS production, and IL-6 and CCL2 secretion were increased in non-stimulated epithelial and stromal cells from endometriotic lesions compared to endometrial cells from endometriosis patients and controls. UPA induced a dose-dependent increase of cell proliferation only in endometriosis, while enhancing ROS production by all cell types evaluated. UPA reduced CCL2 production in controls but failed to do that in endometriosis, whereas TNF-α was undetectable. We conclude that treatment of endometriotic cells with UPA stimulated in vitro proliferation and ROS production and failed to revert the proinflammatory cytokine excess that characterized these cells, unravelling possible mechanisms of drug resistance in the treatment of endometriosis.
B-cell activating factor may be involved in the failure of B-cell depleting therapy with rituximab in immune thrombocytopenia (ITP) by promoting the emergence of splenic long-lived plasma cells. From ...results obtained in mouse models, we hypothesized that combining rituximab with sequential injections of belimumab could increase the rate of response at 1 year in patients with persistent or chronic ITP by preventing the emergence of these long-lived plasma cells. The study was a single-center, single-arm, prospective phase IIb trial investigating the safety and efficacy of rituximab given at a fixed dose of 1,000 mg, 2 weeks apart, combined with five infusions of belimumab, 10 mg/kg at week 0 (W0)+2 days, W2+2 days, W4, W8 and W12 for adults with primary persistent or chronic ITP. The primary endpoint was the total number of patients achieving an overall response (complete response + response) at W52 according to a standard definition. In total, 15 non-splenectomized adults, nine (60%) with persistent IPT and six (40%) with chronic ITP, were included. No severe adverse event, infection, or severe hypogammaglobulinemia was observed. Thirteen patients achieved an initial overall response. At W52, 12 (80%) patients achieved an overall response, including ten (66.7%) with complete response. When compared with a cohort of patients receiving rituximab alone, the kinetics of B-cell repopulation appeared similar, but the number of circulating T-follicular helper cells was significantly decreased with belimumab combination therapy. Combining rituximab and belimumab seems a promising strategy in ITP, with high efficacy and acceptable safety (clinicaltrials gov. Identifier: NCT03154385).
Innate lymphoid cells-2 (ILC2) were shown to be involved in the development of lung or hepatic fibrosis. We sought to explore the functional and phenotypic heterogeneity of ILC2 in skin fibrosis ...within systemic sclerosis (SSc).
Blood samples and skin biopsies from healthy donor or patients with SSc were analysed by immunostaining techniques. The fibrotic role of sorted ILC2 was studied in vitro on dermal fibroblast and further explored by transcriptomic approach. Finally, the efficacy of a new treatment against fibrosis was assessed with a mouse model of SSc.
We found that ILC2 numbers were increased in the skin of patients with SSc and correlated with the extent of skin fibrosis. In SSc skin, KLRG1
ILC2 (natural ILC2) were dominating over KLRG1
ILC2 (inflammatory ILC2). The cytokine transforming growth factor-β (TGFβ), whose activity is increased in SSc, favoured the expansion of KLRG1
ILC2 simultaneously decreasing their production of interleukin 10 (IL10), which regulates negatively collagen production by dermal fibroblasts. TGFβ-stimulated ILC2 also increased myofibroblast differentiation. Thus, human KLRG1
ILC2 had an enhanced profibrotic activity. In a mouse model of SSc, therapeutic intervention-combining pirfenidone with the administration of IL10 was required to reduce the numbers of skin infiltrating ILC2, enhancing their expression of KLRG1 and strongly alleviating skin fibrosis.
Our results demonstrate a novel role for natural ILC2 and highlight their inter-relationships with TGFβ and IL10 in the development of skin fibrosis, thereby opening up new therapeutic approaches in SSc.
Trained immunity is a new concept illustrating that innate immune cells are able to undergo a long‐term metabolic and epigenetic reprogramming after infection or vaccination, thus displaying either a ...pro‐ or an anti‐inflammatory phenotype during a sequential unrelated challenge. Innate immune cells such as natural killer (NK) cells and macrophages constitute a large part of the decidual leukocyte population at the maternal–fetal interface, playing an important role in placental development and as such in fetal growth and development. In this study, we hypothesized that training the innate immune cells before pregnancy could have an impact on pregnancy. To test this hypothesis, we used CBA/J x DBA/2 mouse model to investigate pregnancy outcomes and leukocyte population at the maternal–fetal interface. Although we were not able to show a beneficial effect of LPS‐tolerogenic training on fetal resorption, Bacillus Calmette–Guérin (BCG) training, known to prime innate immune cells to be proinflammatory, led to fetal growth restriction, without aggravating the fetal resorption rate. We also found that BCG training led to less NK cells and macrophages at the maternal–fetal interface at the early stage of placentation (E9.5), associated with a down‐regulation of Ccr3 and Lif mRNA expression. This induced altered leucocyte population profile can be an explanation for the subsequent fetal growth restriction. These data suggest that preconceptional infections‐induced trained immunity could influence pregnancy outcomes.
Graphical
BCG immune training before pregnancy led to IUGR in mice by modifying immune cell frequency in the developing placenta, whereas LPS training had no effect
Autosomal dominant hyper-IgE syndrome (AD-HIES) is typically caused by dominant-negative (DN) STAT3 mutations. Patients suffer from cold staphylococcal lesions and mucocutaneous candidiasis, severe ...allergy, and skeletal abnormalities. We report 12 patients from 8 unrelated kindreds with AD-HIES due to DN IL6ST mutations. We identified seven different truncating mutations, one of which was recurrent. The mutant alleles encode GP130 receptors bearing the transmembrane domain but lacking both the recycling motif and all four STAT3-recruiting tyrosine residues. Upon overexpression, the mutant proteins accumulate at the cell surface and are loss of function and DN for cellular responses to IL-6, IL-11, LIF, and OSM. Moreover, the patients' heterozygous leukocytes and fibroblasts respond poorly to IL-6 and IL-11. Consistently, patients with STAT3 and IL6ST mutations display infectious and allergic manifestations of IL-6R deficiency, and some of the skeletal abnormalities of IL-11R deficiency. DN STAT3 and IL6ST mutations thus appear to underlie clinical phenocopies through impairment of the IL-6 and IL-11 response pathways.
Inborn errors of human interferon gamma (IFN-γ) immunity underlie mycobacterial disease. We report a patient with mycobacterial disease due to inherited deficiency of the transcription factor T-bet. ...The patient has extremely low counts of circulating Mycobacterium-reactive natural killer (NK), invariant NKT (iNKT), mucosal-associated invariant T (MAIT), and Vδ2+ γδ T lymphocytes, and of Mycobacterium-non reactive classic TH1 lymphocytes, with the residual populations of these cells also producing abnormally small amounts of IFN-γ. Other lymphocyte subsets develop normally but produce low levels of IFN-γ, with the exception of CD8+ αβ T and non-classic CD4+ αβ TH1∗ lymphocytes, which produce IFN-γ normally in response to mycobacterial antigens. Human T-bet deficiency thus underlies mycobacterial disease by preventing the development of innate (NK) and innate-like adaptive lymphocytes (iNKT, MAIT, and Vδ2+ γδ T cells) and IFN-γ production by them, with mycobacterium-specific, IFN-γ-producing, purely adaptive CD8+ αβ T, and CD4+ αβ TH1∗ cells unable to compensate for this deficit.
Display omitted
•Human inherited T-bet deficiency underlies severe mycobacterial disease•The development of a variety of IFN-γ-producing lymphocyte subsets is impaired•The production of IFN-γ by innate and innate-like lymphocytes is impaired•Mycobacterium-specific αβ CD4 TH1∗ and CD8 cells produce IFN-γ normally
Human T-bet is involved in the regulation of distinct leukocyte subsets, when compared with its mouse counterpart, with its deficiency underlying severe mycobacterial disease
PDF
