Background Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by defective production of reactive oxygen species in phagocytic cells that results in life-threatening infections ...and severe inflammatory manifestations. The treatment of inflammatory manifestations remains challenging because it can be associated with an increased risk of infections. Previous studies have shown that phagocytes from patients with CGD display a defect in autophagy and a reactive oxygen species–independent activation of the inflammasome. Objective Because the intersections between autophagy and the inflammasome have been observed in patients with various diseases and microbial infections, we investigated the possible benefit of restoring the autophagy defect through rapamycin, a potent autophagy inducer, in the setting of CGD. Methods We studied 15 patients given a diagnosis of CGD and followed in our institution. All patients were free of any active infection at the time of the study. Results We show that patients with CGD present a consistent inflammatory phenotype defined by (1) increased nonclassical and intermediate monocytes, (2) a proinflammatory state of mononuclear phagocytes with increased IL-1β and TNF-α content, (3) a TH 17 bias of CD4+ T cells, (4) and an increase in IL-17A–secreting neutrophil numbers. We document the reversion of CGD inflammatory status by the mammalian target of rapamycin inhibitor rapamycin on the different immune cell subsets. We also provide evidence for the enhancement of rapamycin's inhibitory effect on IL-1β secretion by the IL-1 receptor antagonist anakinra in phagocytes of patients with CGD. Conclusion Altogether, these data open new therapeutic approaches for CGD-related inflammatory manifestations.
Background Inflammatory bowel disease (IBD) is one of the most common chronic gastrointestinal diseases, but the underlying molecular mechanisms remain largely unknown. Studies of monogenic diseases ...can provide insight into the pathogenesis of IBD. Objective We thought to determine the underlying molecular causes of IBD occurring in 2 unrelated families in association with an immune deficiency. Methods We performed genetic linkage analysis and candidate gene sequencing on 13 patients from a large consanguineous family affected by early-onset IBD, progressive immune deficiency, and, in some cases, autoimmunity and alopecia, a condition we named enteropathy-lymphocytopenia-alopecia. The candidate gene was also sequenced in an unrelated patient with a similar phenotype. We performed histologic analysis of patients' intestinal biopsy specimens and carried out functional assays on PBMCs. Gut organoids derived from a patient's biopsy specimen were analyzed. Results We identified biallelic missense mutations in tetratricopeptide repeat domain 7A (TTC7A) in all patients from both families. The resulting TTC7A depletion modified the proliferation, adhesion, and migratory capacities of lymphocytes through inappropriate activation of the RhoA signaling pathway. Normal function was restored by wild-type TTC7A expression or addition of a RhoA kinase inhibitor. The growth and polarity of gut epithelial organoids were also found to be dependent on the RhoA signaling pathway. Conclusions We show that TTC7A regulates the actin cytoskeleton dynamics in lymphocytes through the RhoA signaling pathway and is required in both lymphocytes and epithelial cells for maintaining equilibrium between cell proliferation, migration, polarization, and cell death. Our study highlights variability in the phenotypic expression resulting from TTC7A deficiency and outlines that impairment of both epithelial cells and lymphocytes cooperatively causes IBD.
Background Follicular helper T (TFH ) cells underpin T cell–dependent humoral immunity and the success of most vaccines. TFH cells also contribute to human immune disorders, such as autoimmunity, ...immunodeficiency, and malignancy. Understanding the molecular requirements for the generation and function of TFH cells will provide strategies for targeting these cells to modulate their behavior in the setting of these immunologic abnormalities. Objective We sought to determine the signaling pathways and cellular interactions required for the development and function of TFH cells in human subjects. Methods Human primary immunodeficiencies (PIDs) resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Circulating follicular helper T (cTFH ) cell subsets, memory B cells, and serum immunoglobulin levels were quantified and functionally assessed in healthy control subjects, as well as in patients with PIDs resulting from mutations in STAT3 , STAT1 , TYK2 , IL21 , IL21R , IL10R , IFNGR1/2 , IL12RB1 , CD40LG , NEMO , ICOS , or BTK. Results Loss-of-function (LOF) mutations in STAT3 , IL10R , CD40LG , NEMO , ICOS , or BTK reduced cTFH cell frequencies. STAT3 and IL21/R LOF and STAT1 gain-of-function mutations skewed cTFH cell differentiation toward a phenotype characterized by overexpression of IFN-γ and programmed death 1. IFN-γ inhibited cTFH cell function in vitro and in vivo , as corroborated by hypergammaglobulinemia in patients with IFNGR1/2 , STAT1 , and IL12RB1 LOF mutations. Conclusion Specific mutations affect the quantity and quality of cTFH cells, highlighting the need to assess TFH cells in patients by using multiple criteria, including phenotype and function. Furthermore, IFN-γ functions in vivo to restrain TFH cell–induced B-cell differentiation. These findings shed new light on TFH cell biology and the integrated signaling pathways required for their generation, maintenance, and effector function and explain the compromised humoral immunity seen in patients with some PIDs.
Background Most children with primary immunodeficiencies (PIDs) now reach adulthood. However, few studies have evaluated their health status and health-related quality of life (HRQoL). Objective To ...investigate long-term morbidity, the French Reference Center for PIDs initiated a prospective multicenter cohort: the French Childhood Immune Deficiency Long-term Cohort. The data collected were used to assess the physical health condition of patients who reached adulthood and the effect on their quality of life. Methods Patients were asked to complete health status questionnaires. A severity score (grade 1 mild to grade 4 life-threatening) was assigned to each health condition. The HRQoL of patients was compared with age- and sex-matched French normal values by using the 36-item Short-Form Survey (SF-36) HRQoL questionnaire. Results Among 329 participants, the mean age at evaluation was 27.6 years, with a 21-year mean follow-up after diagnosis; 43% reported at least 1 grade 4 health condition, and 86% reported at least 1 grade 3 (severe) or 4 health condition. Twenty-five (7.6%) patients had been treated for cancer. Compared with the French normal values, adults with PIDs scored significantly lower for all HRQoL domains. HRQoL was strongly associated with the burden of health conditions. The association with grade 4 or grade 3-4 health conditions was highly significant for all physical and mental domains. Conclusion Adults with PIDs diagnosed during childhood experienced a heavy burden of health conditions, which affected their HRQoL. Our results emphasize the need to closely monitor this vulnerable population.
Background Signals emanating from the antigen T-cell receptor (TCR) are required for T-cell development and function. The T lymphocyte–specific protein tyrosine kinase (Lck) is a key component of the ...TCR signaling machinery. On the basis of its function, we considered LCK a candidate gene in patients with combined immunodeficiency. Objective We identify and describe a child with a T-cell immunodeficiency caused by a homozygous missense mutation of the LCK gene (c.1022T>C) resulting from uniparental disomy. Methods Genetic, molecular, and functional analyses were performed to characterize the Lck deficiency, and the associated clinical and immunologic phenotypes are reported. Results The mutant LCK protein (p.L341P) was weakly expressed with no kinase activity and failed to reconstitute TCR signaling in LCK-deficient T cells. The patient presented with recurrent respiratory tract infections together with predominant early-onset inflammatory and autoimmune manifestations. The patient displayed CD4+ T-cell lymphopenia and low levels of CD4 and CD8 expression on the T-cell surface. The residual T lymphocytes had an oligoclonal T-cell repertoire and exhibited a profound TCR signaling defect, with only weak tyrosine phosphorylation signals and no Ca2+ mobilization in response to TCR stimulation. Conclusion We report a new form of T-cell immunodeficiency caused by a LCK gene defect, highlighting the essential role of Lck in human T-cell development and responses. Our results also point out that defects in the TCR signaling cascade often result in abnormal T-cell differentiation and functions, leading to an important risk factor for inflammation and autoimmunity.
Background Combined immunodeficiencies (CIDs) form a heterogeneous group of inherited conditions that affect the development, function, or both of T cells. The treatment of CIDs with allogeneic ...hematopoietic stem cell transplantation (HSCT) is complicated by a high incidence of life-threatening infections and an increased risk of graft-versus-host disease (GVHD). Objective In view of the growing evidence that alloreactivity is mainly derived from human naive T cells, the selective depletion of naive T cells from allografts might constitute a way of reducing alloreactivity while maintaining memory T-cell responsiveness to pathogens. Methods Five consecutive patients with CIDs and chronic viral infections underwent an allogeneic, HLA-mismatched HSCT. Given the patients' infection status and the potential risk of severe GVHD in the mismatched setting, the CD34− fraction of the allograft was depleted of naive T cells by using magnetic CD45RA beads. Results Engraftment occurred in 4 of the 5 patients. No severe GVHD occurred. In the 4 engrafted patients viral infections were cleared within 2 months of the HSCT, and both cellular and humoral immunity were re-established within a year of the HSCT. An early T-cell response against viral pathogens was documented in 2 patients. Conclusion The present pilot study shows that clinical-grade depletion of naive T cells from an allograft through the use of magnetic CD45RA beads seems to be a feasible and efficacious option for the treatment of patients with CIDs at high risk of GVHD, infection, or both in an HLA-mismatched setting.
Background We investigated 7 male patients (from 5 different families) presenting with profound lymphopenia, hypogammaglobulinemia, fluctuating monocytopenia and neutropenia, a poor immune response ...to vaccine antigens, and increased susceptibility to bacterial and varicella zoster virus infections. Objective We sought to characterize the genetic defect involved in a new form of X-linked immunodeficiency. Methods We performed genetic analyses and an exhaustive phenotypic and functional characterization of the lymphocyte compartment. Results We observed hemizygous mutations in the moesin (MSN) gene (located on the X chromosome and coding for MSN) in all 7 patients. Six of the latter had the same missense mutation, which led to an amino acid substitution (R171W) in the MSN four-point-one, ezrin, radixin, moesin domain. The seventh patient had a nonsense mutation leading to a premature stop codon mutation (R533X). The naive T-cell counts were particularly low for age, and most CD8+ T cells expressed the senescence marker CD57. This phenotype was associated with impaired T-cell proliferation, which was rescued by expression of wild-type MSN. MSN-deficient T cells also displayed poor chemokine receptor expression, increased adhesion molecule expression, and altered migration and adhesion capacities. Conclusion Our observations establish a causal link between an ezrin-radixin-moesin protein mutation and a primary immunodeficiency that could be referred to as X-linked moesin-associated immunodeficiency.
...this risk is lower in patients with T-cell-repleted graft versus patients receiving T-cell-depleted transplant.2 During the posttransplant period, several prophylactic or preemptive antiviral ...treatments may be partially effective by inhibiting viral replication and thus stabilizing the viral load.3,4 However, antiviral drugs can also induce drug resistance and be responsible for organ toxicity.5 Because the transfer of donor memory T lymphocytes directed specifically against immunodominant viral antigens has been shown to control ongoing viral infections, we designed a French multicenter pilot trial (Clinicaltrials.gov: NCT01325636) with the aim of treating pediatric or adult recipients of allogeneic HSCT (regardless of the underlying disease).6-8 Inclusion criteria were as follow: (1) donor chimerism 10% or more at inclusion; (2) biological signs of infection with CMV with resistance or intolerance to conventional antiviral treatments, or CMV or ADV disease with documented organ damage; (3) graft versus host activity (<=II) controlled by corticoids (<1 mg/kg) at the time of inclusion; and (4) donor with positive CMV and/or ADV serology. Patient SAE Delay between SAE and specific T-cell infusion P1 Multivisceral failure due to disseminated CMV infectionDeath Day+7Day+31 P2 None NA P3 None NA P4 Sepsis Day+1 P5 Worsening respiratory symptoms 5 mo P6 Alveolar hemorrhage and death Day+3 P7 Gram-negative sepsis Day+12 P8 Pulmonary hypertension and intraalveolar hemorrhageDeath Day+36Day+96 P9 Multivisceral failureDeath Day+10Day+14 P10 Stage III GvHDDeath from ADV pneumonitis Day+5Day+97 P11 Intraalveolar hemorrhage, hematemesisDeath Day+14Day+25 P12 None NA P13 SepsisPneumopathy Day+23Day+48 P14 Respiratory distressDeath from PTLD Day+20Day+33 P15 Acute respiratory distress syndrome due to CMV and ADV and death Day+3 Table E3 Serious adverse event observed in treated patients GvHD, Graft versus host disease; NA, not applicable; P, patient; PTLD, posttransplant lymphoproliferative disease.
SMB cell subset Low (n = 30) Normal (n = 13) P value MZB cell subset Low (n = 17) Normal (n = 13) P value Normal (n = 13) Upper respiratory tract infections 13 11 NS 11 NS Lower respiratory tract ...infections 11 12 NS 9 NS Pneumonia 10 8 NS 2 .017 Bronchiectasis 6 3 NS 0 .041 Autoimmune diseases 2 3 NS 0 NS Splenomegaly 3 2 NS 0 NS Gastroenteritis 3 1 NS 6 .02 Invasive acute infection 4 1 NS 2 NS IgRT 17 6 .0008 11 NS No response to vaccines 9/14 3/11 NS 1/9 NS Normal CD40+IL4-induced proliferation 11/16 10/12 NS 9/9 NS Normal CD40 class-switch recombination 11/16 6/10 NS 9/9 NS Normal BAFF-induced proliferation 6/13 7/12 NS 2/6 NS Normal CpG-induced proliferation 6/13 8/12 NS 3/6 NS Normal anti-A/B allohemagglutinins 2/10 3/9 NS 5/7 NS Table II Characteristics of patients as a function of their SMB and MZB cell counts BAFF, B-cell activating factor; NS, not significant.Low SMB and MZB cell counts were defined as being at least 2 SDs below the age-adjusted normal value (NS, P > .05). Characteristic No. (%) or median (min; max) Sex: male 20 (45.4) Age at onset (y) 1.77 (0.06; 5.9) Age at diagnosis (y) 5.15 (0.33; 17.3) Age at last follow-up (y) 14.46 (4.17; 35.87) Time between symptom onset and diagnosis years 3.00 (0.0; 13.23) Follow-up period (y) 6.29 (0.23; 27.09) Patients with another case in their family 13 (29.5) IgG deficiency 6 (13.6) IgG and IgA deficiency 9 (20.4) IgG and IgM deficiency 3 (6.8) IgA and IgM deficiency 1 (2.2) IgG, IgA, and IgM deficiency 25 (56.8) Patients with upper respiratory tract infections 35 (79.5) Patients with lower respiratory tract infections 33 (75) * Repeated acute bronchitis 17 (38.6) * Pneumonia 20 (45.5) * Bronchiectasis 9 (20.4) Patients with gastroenteritis 10 (22.7) Patients with autoimmune diseases 5 (11.4) Patients with splenomegaly 5 (11.4) Patients with lymphoma 1 (2.2) Table E1 Demographic, clinical, and biological characteristics of patients
Background Ataxia-telangiectasia (A-T) is a rare genetic disease caused by germline biallelic mutations in the ataxia-telangiectasia mutated gene (ATM) that result in partial or complete loss of ATM ...expression or activity. The course of the disease is characterized by neurologic manifestations, infections, and cancers. Objective We studied A-T progression and investigated whether manifestations were associated with the ATM genotype. Methods We performed a retrospective cohort study in France of 240 patients with A-T born from 1954 to 2005 and analyzed ATM mutations in 184 patients, along with neurologic manifestations, infections, and cancers. Results Among patients with A-T, the Kaplan-Meier 20-year survival rate was 53.4%; the prognosis for these patients has not changed since 1954. Life expectancy was lower among patients with mutations in ATM that caused total loss of expression or function of the gene product (null mutations) compared with that seen in patients with hypomorphic mutations because of earlier onset of cancer (mainly hematologic malignancies). Cancer (hazard ratio, 2.7; 95% CI, 1.6-4.5) and respiratory tract infections (hazard ratio, 2.3; 95% CI, 1.4-3.8) were independently associated with mortality. Cancer (hazard ratio, 5.8; 95% CI, 2.9-11.6) was a major risk factor for mortality among patients with null mutations, whereas respiratory tract infections (hazard ratio, 4.1; 95% CI, 1.8-9.1) were the leading cause of death among patients with hypomorphic mutations. Conclusion Morbidity and mortality among patients with A-T are associated with ATM genotype. This information could improve our prognostic ability and lead to adapted therapeutic strategies.
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