scholarly journals Inborn errors of immunity—recent advances in research on the pathogenesis

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Motoi Yamashita ◽  
Kento Inoue ◽  
Tsubasa Okano ◽  
Tomohiro Morio
Keyword(s):  
Immune System ◽  
Hematopoietic Cell Transplantation ◽  
Epigenetic Modification ◽  
Genetic Disorder ◽  
Loss Of Function ◽  
Inborn Errors ◽  
Whole Genome Analysis ◽  
Curative Therapy ◽  
Inborn Errors Of Immunity ◽  
Recent Advances

AbstractPrimary immunodeficiency (PID) is a genetic disorder with a defect of one of the important components of our immune system. Classical PID has been recognized as a disorder with loss of function of the immune system. Recent studies have unveiled disorders with immune dysfunction with autoimmunity, autoinflammation, allergy, or predisposition to malignancy. Some of them were caused by an augmented immune function or a defect in immune regulation. With this background, the term inborn errors of immunity (IEI) is now used to refer to PID in the International Union of Immunological Societies (IUIS) classification. More than 400 responsible genes have been identified in patients with IEI so far, and importantly, many of them identified lately were caused by a heterologous mutation. Moreover, the onset is not necessarily in childhood, and we started seeing more and more IEI patients diagnosed in adulthood in the clinical settings. Recent advances in genetic analysis, including whole-exome analysis, whole-genome analysis, and RNA-seq have contributed to the identification of the disease-causing gene mutation. We also started to find heterogeneity of phenotype even in the patients with the same mutation in the same family, leading us to wonder if modifier gene or epigenetic modification is involved in the pathogenesis. In contrast, we accumulated many cases suggesting genetic heterogeneity is associated with phenotypic homogeneity. It has thus become difficult to deduce a responsible gene only from the phenotype in a certain type of IEI. Current curative therapy for IEI includes hematopoietic cell transplantation and gene therapy. Other curative therapeutic modalities have been long waited and are to be introduced in the future. These include a small molecule that inhibits the gain-of-function of the molecule- and genome-editing technology. Research on IEI will surely lead to a better understanding of other immune-related disorders including rheumatic diseases and atopic disorders.

Role of Flow Cytometry in the Diagnosis of Inborn Errors of Immunity

2022 ◽  
Author(s):  
Thulasi Raman Ramalingam
Keyword(s):  
Flow Cytometry ◽  
Immune System ◽  
B Lymphocyte ◽  
Molecular Genetic ◽  
Clinical History ◽  
Final Diagnosis ◽  
Inborn Errors ◽  
Reliable Technique ◽  
Humoral Immunodeficiency ◽  
Inborn Errors Of Immunity

AbstractInborn errors of immunity (IEI) are a group of inherited heterogeneous disorders affecting the immune system characterized by increased susceptibility to infections, immune dysregulation, and lymphoproliferation. Flow cytometry (FCM) is a rapid and reliable technique for evaluation and enumeration of immune cells. It also helps in understanding the functional and signaling pathways of the immune system. Lymphocyte subset analysis is a simple and effective screening tool in suspected combined and humoral immunodeficiency patients. Qualitative phagocytic defects such as chronic granulomatous disease and leucocyte adhesion defect are easily diagnosed by FCM. Study of intracellular proteins (e.g., BTK, WASP, DOCK8), cytokine production, and signaling molecules (e.g., STAT3) by FCM is very useful but also quite challenging to establish. T and B lymphocyte interaction for normal class switching of B cells can be assessed and can help in diagnosis of combined variable immunodeficiency and hyperimmunoglobulin M syndrome. FCM is also used in posttransplant monitoring of IEI patients and also in prenatal diagnosis in suspected cases. It is also useful in validation of variants of uncertain significance obtained in exome sequencing. FCM results should always be interpreted with clinical history and, if needed, should be confirmed with molecular genetic studies before establishing the final diagnosis. Ensuring good sample quality and running parallel controls with patient samples will avoid the preanalytical and analytical errors. This review describes the applications of FCM in the diagnosis of various IEI.

scholarly journals Inborn errors of immunity to infection

2005 ◽  
Vol 202 (2) ◽  
pp. 197-201 ◽  
Author(s):  
Jean-Laurent Casanova ◽  
Laurent Abel
Keyword(s):  
Immune System ◽  
Natural Selection ◽  
Life Expectancy ◽  
Infectious Diseases ◽  
Life Span ◽  
Human Life ◽  
Human History ◽  
Inborn Errors ◽  
Inborn Errors Of Immunity ◽  
Human Life Span

The immune system's function is to protect against microorganisms, but infection is nonetheless the most frequent cause of death in human history. Until the last century, life expectancy was only ∼25 years. Recent increases in human life span primarily reflect the development of hygiene, vaccines, and anti-infectious drugs, rather than the adjustment of our immune system to coevolving microbes by natural selection. We argue here that most individuals retain a natural vulnerability to infectious diseases, reflecting a great diversity of inborn errors of immunity.

scholarly journals Thymic origins of autoimmunity—lessons from inborn errors of immunity

2021 ◽  
Author(s):  
Rosa Bacchetta ◽  
Kenneth Weinberg
Keyword(s):  
T Cell ◽  
Epigenetic Modification ◽  
Constitutive Expression ◽  
Abnormal Development ◽  
Thymic Epithelial Cells ◽  
Clonal Deletion ◽  
Inborn Errors ◽  
Inborn Errors Of Immunity ◽  
Molecular Events ◽  
And Function

AbstractDuring their intrathymic development, nascent T cells are empowered to protect against pathogens and to be operative for a life-long acceptance of self. While autoreactive effector T (Teff) cell progenitors are eliminated by clonal deletion, the intrathymic mechanisms by which thymic regulatory T cell (tTreg) progenitors maintain specificity for self-antigens but escape deletion to exert their regulatory functions are less well understood. Both tTreg and Teff development and selection result from finely coordinated interactions between their clonotypic T cell receptors (TCR) and peptide/MHC complexes expressed by antigen-presenting cells, such as thymic epithelial cells and thymic dendritic cells. tTreg function is dependent on expression of the FOXP3 transcription factor, and induction of FOXP3 gene expression by tTreg occurs during their thymic development, particularly within the thymic medulla. While initial expression of FOXP3 is downstream of TCR activation, constitutive expression is fixed by interactions with various transcription factors that are regulated by other extracellular signals like TCR and cytokines, leading to epigenetic modification of the FOXP3 gene. Most of the understanding of the molecular events underlying tTreg generation is based on studies of murine models, whereas gaining similar insight in the human system has been very challenging. In this review, we will elucidate how inborn errors of immunity illuminate the critical non-redundant roles of certain molecules during tTreg development, shedding light on how their abnormal development and function cause well-defined diseases that manifest with autoimmunity alone or are associated with states of immune deficiency and autoinflammation.

scholarly journals Human inborn errors of immunity to infection affecting cells other than leukocytes: from the immune system to the whole organism

2019 ◽  
Vol 59 ◽  
pp. 88-100 ◽  
Author(s):  
Shen-Ying Zhang ◽  
Emmanuelle Jouanguy ◽  
Qian Zhang ◽  
Laurent Abel ◽  
Anne Puel ◽  
...  
Keyword(s):  
Immune System ◽  
Inborn Errors ◽  
Inborn Errors Of Immunity

scholarly journals Hematopoietic Cell Transplantation for Inborn Errors of Immunity Other Than Severe Combined Immunodeficiency in Japan: Retrospective Analysis for 1985–2016

2021 ◽  
Author(s):  
Satoshi Miyamoto ◽  
Katsutsugu Umeda ◽  
Mio Kurata ◽  
Masakatsu Yanagimachi ◽  
Akihiro Iguchi ◽  
...  
Keyword(s):  
Cell Transplantation ◽  
Statistical Power ◽  
Hematopoietic Cell Transplantation ◽  
Severe Combined Immunodeficiency ◽  
Management Program ◽  
National Database ◽  
Combined Immunodeficiency ◽  
Inborn Errors ◽  
Respiratory Impairment ◽  
Inborn Errors Of Immunity

Abstract PurposeHematopoietic cell transplantation (HCT) is a curative therapy for most patients with inborn errors of immunity (IEI). We conducted a nationwide study on HCT for patients with IEI other than severe combined immunodeficiency (non-SCID) in Japan.MethodsData from the Japanese national database (Transplant Registry Unified Management Program, TRUMP) for 567 patients with non-SCID IEI, who underwent their first HCT between 1985­ and 2016, were retrospectively analyzed.ResultsThe 10-year overall survival (OS) and event-free survival (EFS) was 74% and 64%, respectively. The 10-year OS for HCT from unrelated bone marrow (URBM), accounting for 39% of HCTs, was comparable to that for HCT from matched-sibling donor (MSD), being 79% and 81%, respectively. HCT from unrelated cord blood (URCB), accounting for 27% of HCTs, was also common, with a 10-year OS of 69% but less robust engraftment. The intensity of conditioning was not associated with OS, hematologic recovery, or retransplantation incidence. Multivariate analyses of data on those receiving HCT during the 2006–2016 period revealed that respiratory impairment at HCT was associated with poor OS (hazard ratio [HR], 2.3; P = 0.01) and that URCB (HR, 2.7; P = 0.003) and related donor other than MSD (HR, 2.7; P = 0.02) were associated with poor EFS.ConclusionsWe present the 1985–2016 status of HCT for non-SCID IEI in Japan with sufficient statistical power, highlighting the potential of URBM as an alternative donor and the substantial applicability of URCB. Detailed evaluation is needed for optimizing the HCT strategy for each IEI.

Impairment of IL-17 Immunity to Candida and IFN-g Immunity to Mycobacterium in Humans with Bi-Allelic Rorc mutations

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 205-205
Author(s):  
Satoshi Okada ◽  
Janet Markle ◽  
Masao Kobayashi ◽  
Jacinta Bustamante ◽  
Jean-Laurent Casanova
Keyword(s):  
T Cells ◽  
Conflicts Of Interest ◽  
Genetic Disorder ◽  
Allelic Loss ◽  
Chronic Mucocutaneous Candidiasis ◽  
Loss Of Function ◽  
Inborn Errors ◽  
Cervical Lymph Nodes ◽  
Γδt Cells ◽  
Ifn Γ

Abstract Inborn errors of human IL-17 immunity underlie chronic mucocutaneous candidiasis (CMC), which is characterized by infections of the skin, nails, oral and genital mucosae with Candida albicans. Inborn errors of human IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD), a rare congenital disorder characterized by susceptibility to infections by poorly virulent intracellular pathogens such as Mycobacterium bovis Bacille Calmette-Guérin vaccines (BCG) and non-tuberculosis Mycobacterium. Rarely, patients may be affected by both candidiasis and mycobacteriosis, including some patients with IL-12p40 and IL-12Rβ1 deficiencies that impair IFN-γ immunity and IL-17 immunity. We studied seven patients from three unrelated consanguineous kindreds with this unusual combination of infectious diseases without known genetic disorder. We combined whole exome sequencing and genome wide linkage analysis, and discovered bi-allelic loss-of-function mutations in RORC, which encodes the transcription factors RORγ and RORγT. All of the seven patients suffered from severe mycobacterial infections, and six also exhibited mild CMC. RORγT is the key transcription factor of Th17 cells, which produce IL-17 and IL-22. Therefore, as predicted by the mouse model, RORγT deficiency prevented the development of IL-17-producing T cells, which accounts for the patients' CMC. Consistent with the phenotype of Rorc-/- mice, these patients presented with mild T cell lymphopenia, small thymus, lack of palpable axillary and cervical lymph nodes, and absence of MAIT and iNKT cells. The patients' severe infections with mycobacteria were not predicted by previous studies of Rorc-/- mice. To explain this unexpected phenotype, we focused on IFN-γ immunity. Leukocytes from RORC-/- patients showed impaired IFN-γ production in response to a mycobacterial challenge, and this defect is probably attributable to the functional impairment of CD4+ CCR6+ CXCR3+ αβ T cells, γδT cells, or both. These findings also suggested that IFN-γ treatment may be beneficial for RORC-/- patients. Moreover, this phenotype does not seem to be human-specific, as we also found that Rorc-/- mice deficient were susceptible to mycobacterial infection. We thus discovered that human RORC is essential not only for the development of IL-17-producing lymphocytes protecting the mucocutaneous barriers against Candida, but also for the activation of IFN-g-producing T cells, and for systemic protection against Mycobacterium. Disclosures No relevant conflicts of interest to declare.

scholarly journals Suppression of m6A mRNA modification by DNA hypermethylated ALKBH5 aggravates the oncological behavior of KRAS mutation/LKB1 loss lung cancer

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Donghong Zhang ◽  
Jinfeng Ning ◽  
Imoh Okon ◽  
Xiaoxu Zheng ◽  
Ganesh Satyanarayana ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Epigenetic Modification ◽  
Suppressor Gene ◽  
Ctcf Binding ◽  
Binding Motif ◽  
Loss Of Function ◽  
Dna Hypermethylation ◽  
Lung Cancer Patients ◽  
Lkb1 Tumor Suppressor ◽  
And Migration

AbstractOncogenic KRAS mutations combined with the loss of the LKB1 tumor-suppressor gene (KL) are strongly associated with aggressive forms of lung cancer. N6-methyladenosine (m6A) in mRNA is a crucial epigenetic modification that controls cancer self-renewal and progression. However, the regulation and role of m6A modification in this cancer are unclear. We found that decreased m6A levels correlated with the disease progression and poor survival for KL patients. The correlation was mediated by a special increase in ALKBH5 (AlkB family member 5) levels, an m6A demethylase. ALKBH5 gain- or loss-of function could effectively reverse LKB1 regulated cell proliferation, colony formation, and migration of KRAS-mutated lung cancer cells. Mechanistically, LKB1 loss upregulated ALKBH5 expression by DNA hypermethylation of the CTCF-binding motif on the ALKBH5 promoter, which inhibited CTCF binding but enhanced histone modifications, including H3K4me3, H3K9ac, and H3K27ac. This effect could successfully be rescued by LKB1 expression. ALKBH5 demethylation of m6A stabilized oncogenic drivers, such as SOX2, SMAD7, and MYC, through a pathway dependent on YTHDF2, an m6A reader protein. The above findings were confirmed in clinical KRAS-mutated lung cancer patients. We conclude that loss of LKB1 promotes ALKBH5 transcription by a DNA methylation mechanism, reduces m6A modification, and increases the stability of m6A target oncogenes, thus contributing to aggressive phenotypes of KRAS-mutated lung cancer.

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