Gene editing for the treatment of primary immunodeficiency disease / 中国当代儿科杂志

Gene editing is an advanced technique based on artificial nucleases and can precisely modify genome sequences. It has shown great application prospects in the field of medicine and has provided a new precision therapy for diseases. Primary immunodeficiency disease is a group of diseases caused by single gene mutation and characterized by recurrent and refractory infections, with an extremely high mortality rate. The application of gene editing has brought hope for curing these diseases. This article reviews the development of gene editing technology and briefly introduces the research and application of gene editing technology in primary immunodeficiency disease.

MonoMAC syndrome / 中国当代儿科杂志

MonoMAC syndrome is a newly discovered immune deficiency syndrome caused by GATA-2 mutation, which is an autosomal dominant genetic disease. MonoMAC syndrome has typical immune cell abnormalities, with severe infection and is prone to develop into a hematological disease. Therapeutics for this disease mainly relies on symptomatic treatment and hematopoietic stem cell transplantation. In this paper, the research advances in clinical manifestations, laboratory tests, pathogenesis, diagnosis and treatment of MonoMAC syndrome are reviewed.

Expression and significance of interleukin-6, interferon-inducible protein-10 and interleukin-17 in serum and synovial fluid of patients with juvenile idiopathic arthritis / 中华儿科杂志

<p><b>OBJECTIVE</b>To detect the disparity of three cytokines interleukin-6 (IL-6), interferon-inducible protein 10 (IP-10) and interleukin-17 (IL-17) in peripheral blood (PB) and synovial fluid (SF) of patients with juvenile idiopathic arthritis (JIA).</p><p><b>METHOD</b>Serum concentrations of the three cytokines were measured in 27 patients with 13 systemic-onset JIA (sJIA), 14 polyarticular JIA (pJIA) and 28 healthy controls using enzyme-linked immunosorbent assay (ELISA). Nineteen patients with no marked arthritis symptom or only temporary arthralgia were enrolled in probable sJIA group. SF from 18 patients with 7 sJIA, 11 pJIA were examined for cytokine levels.</p><p><b>RESULT</b>(1) The statistically significant difference in serum IL-6 was detected between sJIA and healthy control group [28.0(4.2-59.2) ng/L vs. 12.3 (2.1-13.8) ng/L, P < 0.05], but no significant difference between probable sJIA and healthy control group [11.8(7.7-39.2) ng/L vs. 12.3 (2.1-13.8) ng/L, P > 0.05] was found. There were statistically significant differences between sJIA group and healthy control group in serum concentrations of IL-17 [14.0(9.8-34.3) ng/L vs. 9.8 (7.9-16.2) ng/L, P < 0.05], yet compared to healthy control group, no significant difference in concentration level of IL-17 was found in pJIA Group [14.2(9.9-16.9) ng/L vs. 9.8(7.9-16.2) ng/L, P > 0.05].(2) In sJIA and pJIA SF, the median IP-10 level was significantly higher compared to respective PB levels [619.7 (160.9, 873.1) ng/L vs. 64.8 (27.4-111.9) ng/L;660.9 (401.9, 1349.8) ng/L vs. 97.4 (41.9-222.1) ng/L, P < 0.01, respectively], but there was only significant difference in IL-17 between pJIA SF and PB [22.9 (17.1, 45.8) ng/L vs. 14.2 (9.9-16.9) ng/L, P < 0.01].</p><p><b>CONCLUSION</b>IL-6 may play more important role in the pathogenesis of sJIA. Moreover, IL-6 may be the biomarker associated with arthritis in early JIA stage. Both autoinflammation and autoimmune response may be involved in the pathogenesis of sJIA. IL-17 enrichment may only occur in local joint, the levels of IL-17 in PB may not be significantly increased. The prominent expression gradient between SF and PB of IP-10 maybe the basis of performing chemotaxis and further causing joint damage.</p>

Screening for cytotoxic defects with flow cytometric detection of CD107α on natural killer cells and cytotoxic lymphocyte cells / 中华儿科杂志

<p><b>OBJECTIVE</b>To establish a novel flow cytometry-based assay for measuring the expression of lysosomal-associated membrane protein 1 (LAMP-1, CD107α) on the cell surface of natural killer (NK) cells and cytotoxic T lymphocyte (CTL) and evaluate the screening value of this assay for cytotoxic defects-related diseases such as familial hemophagocytic lymphopro-liferative (FHL) syndrome.</p><p><b>METHOD</b>Three suspected Chediak-Higashi Syndrome (CHS) patients, three suspected FHL patients and 10 healthy children were enrolled in the study from October 2010 to June 2011. Their PBMCs were separated and activated overnight with IL-2. After the granule release of NK cells activated by phytohemagglutinin (PHA) and CD8+T cells by anti-CD3, the CD107α expression were analyzed by flow cytometry. The peripheral blood DNA and RNA of the patients were extracted to analyze the pathogenic genes via DNA-PCR/RT-PCR and direct sequencing.</p><p><b>RESULT</b>The CD107α expression on CTL in the ten healthy children significantly increased after activation by anti-CD3 [(0.18 ± 0.07)% vs. (4.47 ± 2.36)%, P < 0.05] and NK cells after activation by PHA [(0.27 ± 0.07)% vs. (5.80 ± 2.83)%, P < 0.05]. The frequency of CD107α-expression NK cells in three suspected CHS after activation was significantly elevated when compared with the healthy control [0.5%, 0.6% vs. (5.80 ± 2.83)%] except patient 2. After the anti-CD3 activation, the frequency of CD107α expression on CTL cells also showed no significant difference [0.3%, 0.9%, 0.2% vs. (4.47 ± 2.36)%] in three patients. All of their mean fluorescence intensity (MFI) showed the same trend. Patient 1 and 3 were identified to have LYST mutations (Patient 1: c.5411-5414 del TTTC, L1741fsX1758 and c.7975 C > T, R2596X; Patient 3: c.4863G > A, R1563H and c.5392-5393delAA, E1739fsX1756). There was no mutation identified in the LYST gene for patient 2. CD107α expression of NK cells and CTL in the suspected FHL patients and in mirror of these findings, no underlying gene variation of PRF, MUNC13-4 and STX11 were identified.</p><p><b>CONCLUSION</b>We developed a method to quantitatively assess cytotoxicity of the NK cells and CTL by measuring the expression of CD107α on the cell membrane, which appeared to be an effective and rapid screening test for cytotoxic defects-related diseases such as FHL and other HLH secondary to primary immunodeficiency.</p>

Genetic and proteinic analysis of a Chinese boy with X-linked lymphoproliferative disease and his maternal relatives / 中华儿科杂志

<p><b>OBJECTIVE</b>X-linked lymphoproliferative disease (XLP), a genetic disorder characterized by immunodeficiency to Epstein-Barr virus (EBV) infection, has been linked to mutations in the SH2D1A gene. XLP patient displays EBV associated fulminant infectious mononucleosis or hemophagocytic lymphohistocytosis, hypogammaglobulinemia or malignant lymphoma. Here we report the clinical features, gene mutation and SAP expression on PBMCs of a Chinese patient with XLP and potential carriers.</p><p><b>METHOD</b>A 6 years old male patient and his maternal relatives were enrolled in this study. The patient was found to have with a renal Burkitt lymphoma on the right waist at 5 years of age by accident. His elder brother and a maternally related cousin both died of multiple systemic organ dysfunction syndrome (MODS) due to fulminant infectious mononucleosis (FIM) at the age of one year. The patient and his maternal relatives were subjected to detection of SAP expression on the PBMCs by flow cytometry and gene mutation analysis of SH2D1A by using PCR based on genomic DNA.</p><p><b>RESULT</b>The patient exhibited 536.9 copy/ml level of circulating EBV-DNA during remission. Sequence analysis showed that the patient harbored a nonsense mutation in exon 2 (C462T), resulting in a premature stop codon (Arg55X). His mother and some of the maternal relatives were proved to be carriers of this mutation. SAP expression from the patient was significantly reduced as compared to normal individual and the carriers.</p><p><b>CONCLUSION</b>We identified a Chinese XLP case genetically. Assessment of SAP expression on PBMCs by flow cytometry seemed to be an effective rapid diagnostic method for this disease. Absence of EBV infection does not diminish the possibility of XLP.</p>

A compound heterozygosity mutation in the interleukin-7 receptor-alpha gene resulted in severe combined immunodeficiency in a Chinese patient / 中华儿科杂志

<p><b>OBJECTIVE</b>Mutation in the interleukin-7 receptor-alpha (IL-7R alpha) chain causes a rare type of severe combined immunodeficiency (SCID) with presence of NK cells in the peripheral blood. Here we report the molecular and clinical characterization of a compound heterozygosity mutation in the interleukin-7 receptor-alpha gene that resulted in SCID in a patient firstly from China.</p><p><b>METHOD</b>A 5 month-old male patient and his parents were enrolled in this study. Since 15 days of age, the patient had had recurrent fever, persistent cough and diarrhea. He was in poor general condition with pyorrhea and ulceration of the BCG scar. His brother died of severe infection at 4 months of age. He was initially diagnosed as SCID according to clinical manifestation and immunological analysis. A panel of SCID candidate genes including IL-2RG, RAG1/RAG2 and IL-7R alpha of patient and his parents were amplified by polymerase chain reaction (PCR) from genomic DNA. Reverse transcription polymerase chain reaction (RT-PCR) was used to amplify the IL-7R alpha transcripts. Sequencing was performed directly on the PCR products forward and reversely.</p><p><b>RESULT</b>The serum immunoglobulin (Ig) profile was IgG 6867 mg/L (normal range, 3050 - 8870 mg/L); IgM 206 mg/L and IgA 249 mg/L, IgE 2.3 IU/ml (normal range < 150 IU/ml). The patient was treated with IVIG previously. There were no T-cells but increased percentage of B-cells (58%) and NK cells (42%) in the peripheral blood was found. Needle biopsies from enlarged axillary lymph node was identified positive for Mycobacterium bovis under microscope and by culture. The patient had a compound heterozygosity mutation in the IL-7R alpha gene:on one allele, there was a splice-junction mutation in intron 4 (intron 4(+1)G > A), for which his father was a carrier; whereas on the other allele, a nonsense mutation at position 638 in exon 5 with a premature stop codon (638 C > T, R206X) was identified, for which his mother was a carrier. The splice-junction mutation in intron 4 of IL-7R alpha was firstly reported. The IL-7R alpha mRNA expression of the patient was remarkably reduced whereas the parents had relatively normal IL-7R alpha mRNA expression. IL-7R alpha cDNA of the patient was amplified by nested PCR. The PCR products were purified, cloned with a TA Cloning Kit and sequenced directly. A 64 bp deletion was found in exon 4 of IL-7R alpha. No mutation was found in IL-2RG and RAG1/RAG2 of the patient and his parents.</p><p><b>CONCLUSION</b>This is the first case with a compound heterozygosity mutation in the IL-7R receptor alpha gene and T-B+NK+ phenotype from China. Intron 4(+1)G > A was a novel mutation.</p>

A novel missense mutation of FOXP3 causes immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome in a Chinese child / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate variation of FOXP3 and it's expression in male children presented with severe and early-onset enteropathy, rash with or without insulin-dependent diabetes mellitus (IDDM).</p><p><b>METHODS</b>Four male children presented with severe and early-onset enteropathy, rash, with or without IDDM were subjected to detection of FOXP3 expression on the PBMC by flow cytometry and FOXP3 gene analysis. The maternal gene analysis was subsequently performed once the variant FOXP3 gene was found. All 11 exons and splice sites within FOXP3 gene were amplified by polymerase chain reaction (PCR) from genomic DNA. Reverse transcription polymerase chain reaction was used to amplify the FOXP3 transcripts. Sequence analysis was performed directly on the bulk PCR products forwardly and reversely. The candidate mutation site was compared with that of 100 healthy controls to exclude polymorphism. Flow cytometry was used to determine FOXP3 expression on CD4+CD25+ T cells and the frequency of Tregs in CD4+ T cells.</p><p><b>RESULTS</b>One of the 4 patients showed a G13128A genetic variation in exon 11, which resulted in a Met370Ile substitution. No sequence variations were found at the same site in any of 100 healthy controls, indicating that the Met370Ile substitution is not a polymorphism but a novel missense mutation. The patient's mother was identified as a carrier for this mutation. There was no reduced frequency of Tregs in the peripheral blood of the patient and FOXP3 protein expression is normal as compared with controls.</p><p><b>CONCLUSION</b>A novel missense mutation of FOXP3 which causes IPEX phenotype was identified in a Chinese child according to immunologic screening and gene sequencing. Infants with early-onset IDDM and persistent diarrhea should be suspected as IPEX, FOXP3 gene analysis will be a reliable diagnostic approach to IPEX.</p>