Compound heterozygous CORO1A mutations in siblings with a mucocutaneous-immunodeficiency syndrome of epidermodysplasia verruciformis-HPV, molluscum contagiosum and granulomatous tuberculoid leprosy.
ABSTRACT: Coronin-1A deficiency is a recently recognized autosomal recessive primary immunodeficiency caused by mutations in CORO1A (OMIM 605000) that results in T-cell lymphopenia and is classified as T(-)B(+)NK(+)severe combined immunodeficiency (SCID). Only two other CORO1A-kindred are known to date, thus the defining characteristics are not well delineated. We identified a unique CORO1A-kindred.We captured a 10-year analysis of the immune-clinical phenotypes in two affected siblings from disease debut of age 7 years. Target-specific genetic studies were pursued but unrevealing. Telomere lengths were also assessed. Whole exome sequencing (WES) uncovered the molecular diagnosis and Western blot validated findings.We found the compound heterozygous CORO1A variants: c.248_249delCT (p.P83RfsX10) and a novel mutation c.1077delC (p.Q360RfsX44) (NM_007074.3) in two affected non-consanguineous siblings that manifested as absent CD4CD45RA(+) (naïve) T and memory B cells, low NK cells and abnormally increased double-negative (DN) ?? T-cells. Distinguishing characteristics were late clinical debut with an unusual mucocutaneous syndrome of epidermodysplasia verruciformis-human papilloma virus (EV-HPV), molluscum contagiosum and oral-cutaneous herpetic ulcers; the older female sibling also had a disfiguring granulomatous tuberculoid leprosy. Both had bilateral bronchiectasis and the female died of EBV+ lymphomas at age 16 years. The younger surviving male, without malignancy, had reproducibly very short telomere lengths, not before appreciated in CORO1A mutations.We reveal the third CORO1A-mutated kindred, with the immune phenotype of abnormal naïve CD4 and DN T-cells and newfound characteristics of a late/hypomorphic-like SCID of an EV-HPV mucocutaneous syndrome with also B and NK defects and shortened telomeres. Our findings contribute to the elucidation of the CORO1A-SCID-CID spectrum.
Project description:Coronin-1A (CORO1A) is a regulator of actin dynamics important for T-cell homeostasis. CORO1A deficiency causes T(-)B(+) natural killer-positive severe combined immunodeficiency or T-cell lymphopenia with severe viral infections. However, because all known human mutations in CORO1A abrogate protein expression, the role of the protein's functional domains in host immunity is unknown.We sought to identify the cause of the primary immunodeficiency in 2 young adult siblings with a history of disseminated varicella, cutaneous warts, and CD4(+) T-cell lymphopenia.We performed immunologic, genetic, and biochemical studies in the patients, family members, and healthy control subjects.Both patients had CD4(+) T-cell lymphopenia and decreased lymphocyte proliferation to mitogens. IgG, IgM, IgA, and specific antibody responses were normal. Whole-genome sequencing identified a homozygous frameshift mutation in CORO1A disrupting the last 2 C-terminal domains by replacing 61 amino acids with a novel 91-amino-acid sequence. The CORO1A(S401fs) mutant was expressed in the patients' lymphocytes at a level comparable with that of wild-type CORO1A in normal lymphocytes but did not oligomerize and had impaired cytoskeletal association. CORO1A(S401fs) was associated with increased filamentous actin accumulation in T cells, severely defective thymic output, and impaired T-cell survival but normal calcium flux and cytotoxicity, demonstrating the importance of CORO1A oligomerization and subcellular localization in T-cell homeostasis.We describe a truncating mutation in CORO1A that permits protein expression and survival into young adulthood. Our studies demonstrate the importance of intact CORO1A C-terminal domains in thymic egress and T-cell survival, as well as in defense against viral pathogens.
Project description:Short telomeres are frequently identified in patients with idiopathic pulmonary fibrosis (IPF) and its inherited form, familial interstitial pneumonia (FIP). We identified a kindred with FIP with short telomeres who did not carry a mutation in known FIP genes TERT or hTR . We performed targeted sequencing of other telomere-related genes to identify the genetic basis of FIP in this kindred. The proband was a 69 year-old man with dyspnea, restrictive pulmonary function test results, and reticular changes on high-resolution CT scan. An older male sibling had died from IPF. The proband had markedly shortened telomeres in peripheral blood and undetectably short telomeres in alveolar epithelial cells. Polymerase chain reaction-based sequencing of NOP10 , TINF2 , NHP2 , and DKC1 revealed that both affected siblings shared a novel A to G 1213 transition in DKC1 near the hTR binding domain that is predicted to encode a Thr405Ala amino acid substitution. hTR levels were decreased out of proportion to DKC1 expression in the T405A DKC1 proband, suggesting this mutation destabilizes hTR and impairs telomerase function. This DKC1 variant represents the third telomere-related gene identified as a genetic cause of FIP. Further investigation into the mechanism by which dyskerin contributes to the development of lung fibrosis is warranted.
Project description:We report outcomes after hematopoietic stem cell transplant for three patients with X-MAID, including 1 patient from the originally described cohort and two brothers with positive TREC newborn screening for SCID who were found to have a T-B-NK+ SCID phenotype attributable to X-linked moesin associated immunodeficiency (X-MAID). A c.511C>T variant in moesin was identified via exome sequencing in the older of these siblings in the setting of low lymphocyte counts and poor proliferative responses consistent with SCID. He received reduced intensity conditioning due to CMV, and was transplanted with a T-depleted haploidentical (maternal) donor. His post-transplant course was complicated by hemolytic anemia, neutropenia, and sepsis. He had poor engraftment, requiring a 2nd transplant. His younger brother presented with the same clinical phenotype and was treated with umbilical cord blood transplant following myeloablative conditioning, has engrafted and is doing well. The third case also presented with severe lymphopenia in infancy, received a matched related bone marrow transplant following myeloablative conditioning, has engrafted and is doing well. These cases represent a novel manifestation of non-radiosensitive X-linked form of T-B-NK+ SCID that is able to be detected by TREC based newborn screening and effectively treated with HCT.
Project description:Human noroviruses (HuNoVs) are a leading cause of acute gastroenteritis worldwide. It is unclear which arm of the immune system regulates resistance to HuNoV infection. Thus, we studied the pathogenesis of human norovirus (HuNoV) in T-B-NK+ Severe Combined Immunodeficiency (SCID) gnotobiotic pigs to investigate the role of innate (especially, natural killer (NK) cells) immunity in HuNoV infection. Forty SCID and non-SCID pigs were randomly grouped: 1) SCID+HuNoV (n?=?12); 2) non-SCID+HuNoV (n?=?14); 3) SCID mock-inoculated (n?=?6); and 4) non-SCID mock-inoculated (n?=?8). Pigs (8-14-day-old) were inoculated orally with GII.4 HuNoV strain HS292 (mean 9.1 log10 genomic equivalents/pig) or mock. Daily fecal consistency and fecal viral RNA shedding, and histopathology (at euthanasia) were evaluated. Frequencies of blood and ileal T, B, and NK cells were analyzed by flow cytometry, and a NK cell cytotoxicity assay was performed at post-inoculation day (PID) 8. Unlike the increased infectivity of HuNoV observed previously in T-B-NK- SCID pigs (Lei et al., 2016. Sci. Rep. 6, 25,222), there was no significant difference in frequency of pigs with diarrhea and diarrhea days between T-B-NK+ SCID+HuNoV and non-SCID+HuNoV groups. Cumulative fecal HuNoV RNA shedding at PIDs 1-8, PIDs 9-27, and PIDs 1-27 also did not differ statistically. These observations coincided with the presence of NK cells and NK cell cytotoxicity in the ileum and blood of the SCID pigs. Based on our observations, innate immunity, including NK cell activity, may be critical to mediate or reduce HuNoV infection in T-B-NK+ SCID pigs, and potentially in immunocompetent patients.
Project description:Severe combined immunodeficiency (SCID) can be cured by using allogeneic hematopoietic stem cell transplantation, and the absence of host immunity often obviates the need for preconditioning. Depending on the underlying genetic defect and when blocks in differentiation occur during lymphocyte ontogeny, infants with SCID have absent or greatly reduced numbers of functional T cells. Natural killer (NK) cell populations are usually absent in the SCID-X1 and Janus kinase 3 forms of SCID and greatly reduced in adenosine deaminase deficiency SCID but often present in other forms of the disorder.To determine if SCID phenotypes indicate host permissiveness to donor cell engraftment.A retrospective data analysis considered whether host NK cells influenced donor T-cell engraftment, immune reconstitution, and long-term outcomes in children who had undergone nonconditioned allogeneic stem cell transplantation between 1990 and 2011 in the United Kingdom. Detailed analysis of T- and B-cell immune reconstitution and donor chimerism was compared between the NK(+) (n = 24) and NK(-) (n = 53) forms of SCID.Overall, 77 children underwent transplantation, with survival of 90% in matched sibling donor/matched family donor transplants compared with 60% when alternative donors were used. Infants with NK(-)SCID were more likely to survive than NK(+) recipients (87% vs 62%, P < .01) and had high-level donor T-cell chimerism with superior long-term recovery of CD4 T-cell immunity. Notably, 33% of children with NK(+)SCID required additional transplantation procedures compared with only 8% of children with NK(-)SCID (P < .005).NK(-)SCID disorders are highly permissive for donor T-cell engraftment without preconditioning, whereas the presence of NK cells is a strong indicator that preparative conditioning is required for engraftment of T-cell precursors capable of supporting robust T-cell reconstitution.
Project description:Dyskeratosis congenita (DC) is a telomere-mediated syndrome defined by mucocutaneous features. The X-linked mode of inheritance accounts for half the cases, and is thought to predominantly manifest in childhood as bone marrow failure. We identified two male probands who presented in the fifth decade with idiopathic pulmonary fibrosis and cancer. Their pedigrees displayed consecutively affected generations. Five of six females (83%) manifested mucocutaneous features of DC, and two had wound-healing complications. No mutations in autosomal dominant telomere genes were present, but exome sequencing revealed novel variants in the X-chromosome DKC1 gene that predicted missense mutations in conserved residues, p.Thr49Ser and p.Pro409Arg. Variants segregated with the telomere phenotype, and affected females were heterozygotes, showing skewed X-inactivation. Telomerase RNA levels were compromised in cells from DKC1 mutation carriers, consistent with their pathogenic role. These findings indicate that females with heterozygous DKC1 mutations may be at increased risk for developing penetrant telomere phenotypes that, at times, may be associated with clinical morbidity.
Project description:Natural killer (NK) cells contribute to control of HIV/SIV infection. We defined macaque NK-cell subsets based on expression of CD56 and CD16 and found their distribution to be highly disparate. CD16(+) NK cells predominated in peripheral blood, whereas most mucosal NK cells were CD56(+), and lymph nodes contained both CD56(+) and CD16(-)CD56(-) (double-negative [DN]) subsets. Functional profiles were also distinct among subsets--CD16(+) NK cells expressed high levels of cytolytic molecules, and CD56(+) NK cells were predominantly cytokine-secreting cells, whereas DN NK possessed both functions. In macaques chronically infected with SIV, circulating CD16(+) and DN NK cells were expanded in number and, although markers of cytoxicity increased, cytokine secretion decreased. Notably, CD56(+) NK cells in SIV-infected animals up-regulated perforin, granzyme B, and CD107a. In contrast, the lymph node-homing molecules CD62 ligand (CD62L) and C-C chemokine receptor type 7 (CCR7), which are expressed primarily on CD56(+) and DN NK cells, were significantly down-regulated on NK cells from infected animals. These data demonstrate that SIV infection drives a shift in NK-cell function characterized by decreased cytokine production, expanded cytotoxicity, and trafficking away from secondary lymphoid organs, suggesting that the NK-cell repertoire is not only heterogeneous but also plastic.
Project description:DOCK2 is a guanine-nucleotide-exchange factor for Rac proteins. Activated Rac serves various cellular functions including the reorganization of the actin cytoskeleton in lymphocytes and neutrophils and production of reactive oxygen species in neutrophils. Since 2015, six unrelated patients with combined immunodeficiency and early-onset severe viral infections caused by bi-allelic loss-of-function mutations in DOCK2 have been described. Until now, the function of phagocytes, specifically neutrophils, has not been assessed in human DOCK2 deficiency. Here, we describe a new kindred with four affected siblings harboring a homozygous splice-site mutation (c.2704-2 A?>?C) in DOCK2. The mutation results in alternative splicing and a complete loss of DOCK2 protein expression. The patients presented with leaky severe combined immunodeficiency or Omenn syndrome. The novel mutation affects EBV-B cell migration and results in NK cell dysfunction similar to previous observations. Moreover, both cytoskeletal rearrangement and reactive oxygen species production are partially impaired in DOCK2-deficient neutrophils.
Project description:NK cells are a major component of the antitumour immune response that limits tumour progression. However, it has been reported that tumour-infiltrating NK (TINK) cells from patients with non-small-cell lung carcinoma (NSCLC) exhibit profound defects in degranulation and IFN-? production. In support of this notion, we report a novel mechanism associated with tumour escape from NK cell-mediated antitumour immunity in lung carcinoma. In this study, we investigated the phenotypic profile of TINK cells based on the expression of the NK-cell maturation markers CD11b and CD27. Interestingly, we found a substantial CD11b(-)CD27(-) (DN) NK-cell population harboured within the tumour tissues. The presence of this CD11b(-)CD27(-) NK subset indicated that the TINK cells were of an immature and inactive phenotype. Remarkably, we determined that the presence of DN NK cells had an impact on the clinical outcomes of patients with NSCLC, as the frequency of tumour-infiltrating DN NK cells was positively correlated with the tumour stage and tumour size. We further used a murine Lewis lung cancer (LLC) model to confirm the correlation between the frequency of tumour-infiltrating DN NK cells and the progression of lung carcinoma. Together, our findings demonstrate that the tumour microenvironment may render TINK cells less tumouricidal and thereby contribute to cancer progression.
Project description:The contribution of Epstein-Barr virus (EBV) to the development of specific types of benign lymphoproliferations and malignant lymphomas has been extensively studied since the discovery of the virus over the last 50 years. The importance and better understanding of the EBV-associated lymphoproliferative disorders (LPD) of B, T or natural killer (NK) cell type has resulted in the recognition of new entities like EBV+ mucocutaneous ulcer or the addition of chronic active EBV (CAEBV) infection in the revised 2016 World Health Organization (WHO) lymphoma classification. In this article, we review the definitions, morphology, pathogenesis, and evolving concepts of the various EBV-associated disorders including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), EBV+ mucocutaneous ulcer, DLBCL associated with chronic inflammation, fibrin-associated DLBCL, lymphomatoid granulomatosis, the EBV+ T and NK-cell LPD of childhood, aggressive NK leukaemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity of primary EBV+ nodal T- or NK-cell lymphoma. The current knowledge regarding the pathogenesis of B-cell lymphomas that can be EBV-associated including Burkitt lymphoma, plasmablastic lymphoma and classic Hodgkin lymphoma will be also explored.