NCF1 EKZON 2 HETEROZIGOT GT DELESYONU BULUNAN AILEDE FRAGMENT ANALIZININ TANISAL KULLANIMI

NCF1 EKZON 2 HETEROZIGOT GT DELESYONU BULUNAN AILEDE FRAGMENT ANALIZININ TANISAL KULLANIMI Zeynep Akidağı, Sevil Özsoy, Nezihe Köker, Mustafa Yavuz Köker Erciyes Üniversitesi Tıp Fakültesi, İmmünoloji Ana Bilim Dalı, ÖZET Kayseri Kronik granülomatöz hastalık (KGH), fagositlerde bulunan NADPH oksidaz enziminin fonksiyon görememesi ile karakterize olan X’e bağlı ya da otozomal resesif (OR) kalıtsal geçiş gösteren primer immün yetmezlik hastalığıdır. NADPH enzimi, gp91phox, p22phox, p67phox, p40phox ve p47phox protein alt birimlerinden oluşur ve bu protein alt birimlerinin herhangi birinin eksikliğinde KGH ortaya çıkar. Bu hastalığın otozomal resesif formuna sebep olan ve p47 phox protein defektine yol açan NCF1 genindeki homozigot GT delesyonu fragment analizi ile kolaylıkla saptanabilir. Ayrıca heterozigot GT delesyonu bulunan taşıyıcı bireyler ve bu mutasyonu taşımayan sağlıklı bireyler de fragment analizi ile saptanabildiği gibi 2:1 psödogen/ gen oranı ile belirtilen normal gen oranı ve 1:2 psödogen/ gen oranı ile ifade edilen füzyon genler de bu yöntem ile tespit edilebilir (Heywort, 2003). Amaç: KGH tanısı almış hastalarda GT delesyonu taşıyıcılığını fragment analizi ile tespit etmek. Yöntem: Çalışmamızda Erciyes Üniversitesi İmmün yetmezlik laboratuvarında KGH tanısı konmuş hasta ve aile bireyleri ile çalışıldı. Çalışmada KGH hastalarında GT delesyonu taşıyıcılığı fragment analizi yöntemiyle araştırıldı. Bulgular: Çalışmaya dahil edilen hasta ve aile bireyleri arasından bir X-KGH (KGH hastalığın X’ e bağlı formu) hastasının taşıyıcı annesinde NCF1 geni ve psödogeni arasında gerçekleşen gen füzyonu ve buna bağlı oluşan füzyon gen varlığı fragment analizi ile tespit edildi. Sonuç: Fragment analizi ile otozomal kronik granülomatöz hastalığın tanısını koymanın yanı sıra genler arasında gerçekleşen gen füzyonu sonucunda meydana gelen füzyon genleri de tespit etmenin mümkün olabileceği anlaşıldı. Anahtar Kelimeler: Kronik granülomatöz hastalık, Fragment analiz, Füzyon gen Kaynaklar 1. Heyworth, P. G., Cross, A. R., & Curnutte, J. T. (2003). Chronic granulomatous disease. Current Opinion in Immunology, 15(5), 578–584. Anahtar Kelimeler: Kronik granülomatöz hastalık, Fragment analiz, Füzyon ge

An Atypical Case with Chronic Granulomatous Disease and Kabuki Syndrome

Chronic granulomatous disease (CGD) is a rare inherited immunodeficiency that arises from defects in the NADPH oxidase complex, primarily affecting the respiratory burst in neutrophils. Kabuki syndrome (KS) is a rare genetic syndrome and often present with facial, skeletal, visceral and cardiac anomalies, immunological defects and varying degrees of mental retardation. A 20-year-old male was admitted with the complaints of the recurrent abscess. He had a history of recurrent abscesses and long-term antituberculosis treatment. Cytometric functional analysis, Sanger sequencing and whole-exome sequencing were used for the diagnosis of CGD. Both AR-CGD (p67phox defect) with homozygous c.229C>T nonsense mutation in NCF2 gene and heterozygous nucleotide change c.3983G>A in the KMT2D gene causing a novel missense mutation p. Arg1328Gln resulted in Kabuki syndrome. To our knowledge, this is the first report of both CGD and Kabuki syndrome combined in a single patient. CGD is always considered for the differential diagnosis during BCGitis history and recurrent skin abscess

Kindlin3-Dependent CD11b/CD18-Integrin Activation Is Required for Potentiation of Neutrophil Cytotoxicity by CD47-SIRPα Checkpoint Disruption.

The CD47–signal regulatory protein-alpha (SIRPα) immune checkpoint constitutes a therapeutic target in cancer, and initial clinical studies using inhibitors of CD47–SIRPα interactions in combination with tumor-targeting antibodies show promising results. Blockade of CD47–SIRPα interaction can promote neutrophil antibody-dependent cellular cytotoxicity (ADCC) toward antibody-opsonized targets. Neutrophils induce killing of antibody-opsonized tumor cells by a process identified as trogoptosis, a necrotic/lytic type of cancer cell death that involves trogocytosis, the antibody-mediated endocytic acquisition of cancer membrane fragments by neutrophils. Both trogocytosis and killing strictly depend on CD11b/CD18-(Mac-1)–mediated neutrophil–cancer cell conjugate formation, but the mechanism by which CD47–SIRPα checkpoint disruption promotes cytotoxicity has remained elusive. Here, by using neutrophils from patients with leukocyte adhesion deficiency type III carrying&nbsp;FERMT3&nbsp;gene mutations, hence lacking the integrin-associated protein kindlin3, we demonstrated that CD47–SIRPα signaling controlled the inside-out activation of the neutrophil CD11b/CD18-integrin and cytotoxic synapse formation in a kindlin3-dependent fashion. Our findings also revealed a role for kindlin3 in trogocytosis and an absolute requirement in the killing process, which involved direct interactions between kindlin3 and CD18 integrin. Collectively, these results identified a dual role for kindlin3 in neutrophil ADCC and provide mechanistic insights into the way neutrophil cytotoxicity is governed by CD47–SIRPα interactions</p

Hematologically important mutations: X-linked chronic granulomatous disease (fourth update)

International audienceChronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe bacterial and fungal infections. The disease is caused by a lack of superoxide production by the leukocyte enzyme NADPH oxidase. Superoxide and subsequently formed other reactive oxygen species (ROS) are instrumental in killing phagocytosed micro-organisms in neutrophils, eosinophils, monocytes and macrophages. The leukocyte NADPH oxidase is composed of five subunits, of which the enzymatic component is gp91phox, also called Nox2. This protein is encoded by the CYBB gene on the X chromosome. Mutations in this gene are found in about 70% of all CGD patients in Europe and in about 20% in countries with a high ratio of parental consanguinity. This article lists all mutations identified in CYBB and should therefore help in genetic counseling of X-CGD patients' families. Moreover, apparently benign polymorphisms in CYBB are also given, which should facilitate the recognition of disease-causing mutations. In addition, we also include some mutations in G6PD, the gene on the X chromosome that encodes glucose-6-phosphate dehydrogenase, because inactivity of this enzyme may lead to shortage of NADPH and thus to insufficient activity of NADPH oxidase. Severe G6PD deficiency can induce CGD-like symptoms

Hematologically important mutations: The autosomal forms of chronic granulomatous disease (third update)

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe, recurrent bacterial and fungal infections. The disease is caused by mutations in the genes encoding the components of the leukocyte NADPH oxidase. This enzyme produces superoxide, which is subsequently metabolized to hydrogen peroxide and other reactive oxygen species (ROS). These products are essential for intracellular killing of pathogens by phagocytic leukocytes (neutrophils, eosinophils, monocytes and macrophages). The leukocyte NADPH oxidase is composed of five subunits, four of which are encoded by autosomal genes. These are CYBA, encoding p22(phox), NCF1, encoding p47(phox), NCF2, encoding p67(phox) and NCF4, encoding p40(phox). This article lists all mutations identified in these genes in CGD patients. In addition, cytochrome b(558) chaperone-1 (CYBC1), recently recognized as an essential chaperone protein for the expression of the X-linked NADPH oxidase component gp91(phox) (also called Nox2), is encoded by the autosomal gene CYBC1. Mutations in this gene also lead to CGD. Finally, RAC2, a small GTPase of the Rho family, is needed for activation of the NADPH oxidase, and mutations in the RAC2 gene therefore also induce CGD-like symptoms. Mutations in these last two genes are also listed in this article