FcγRIIa and Fcγ RIIIa genes polymorphism in Egyptian children with primary immune thrombocytopenia

Abstract Introduction Phagocytosis of autoantibody-sensitized coated platelets through Fc gamma receptors on phagocytic cells is an important mechanism of thrombocytopenia in primary immune thrombocytopenia (ITP). Objective We aimed to investigate the contribution of the FcγRIIa and FcγRIIIa genes polymorphism to the risk of ITP and their association with disease characteristics in Egyptian children. Methods A case control study was conducted on eighty children with primary ITP and eighty age and sex healthy matched subjects as a control group. The FcγRIIa and FcγRIIIa genes polymorphism was detected using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results We found that the FcγRIIa‐131H and ‐131R allele frequencies were 51.3 % and 48.7%, respectively, in children with ITP, versus 75% and 25%, respectively, in controls (p= 0.002). The compound heterozygous HR genotype was significantly higher in ITP patients (p < 0.05). The FcγRIIIa-158F and ‐158V allele frequencies were 46.3% and 53.7%, respectively, in children with ITP, versus 70% and 30%, respectively, in controls (p= 0.002). The compound heterozygous VF genotype was significantly higher in ITP patients (p < 0.05). The combined HR/FV genotype was 47.5% in ITP patients, versus 10% in controls (p < 0.001). No significant difference was found between children with newly diagnosed ITP and those who developed chronic ITP, regarding the frequency distribution of the FcγRIIa and FcγRIIIa alleles and genotypes (p > 0.05). Conclusion There is a possible association of the FcγRIIa and FcγRIIIa genes polymorphism with the risk for, and genetic susceptibility to ITP in Egyptian children, but large-scale studies are still needed to support our findings.

Distribution of monocyte subsets and their surface CD31 intensity are associated with disease course and severity of hemorrhagic fever with renal syndrome / 细胞与分子免疫学杂志

Objective To investigate the relationship between disease courses and severity and monocyte subsets distribution and surface CD31 intensity in patients of hemorrhagic fever with renal syndrome (HFRS). Methods Peripheral blood samples from 29 HFRS patients and 13 normal controls were collected. The dynamic changes of classical monocyte subsets (CD14++CD16-), intermediated monocyte subsets (CD14++CD16+) and non-classical monocyte subsets (CD14+CD16++) and the mean fluorescent intensity (MFI) of CD31 on monocyte subsets were detected by multiple-immunofluorescent staining and flow cytometry. Results In acute phase of HFRS, the ratio of classical monocyte subsets to total monocytes was dramatically decreased compared to convalescent phase and normal control. It was still much lower in convalescent phase compared to normal controls. The ratio of classical monocyte subsets to total monocytes were decreased in HFRS patients compared to that in normal control, whereas there was no difference between severe/critical groups and mild/moderate groups. On the contrary, the ratio of intermediate monocyte subsets to total monocytes in acute phase of HFRS was significantly increased compared to convalescent phase and normal control. The ratio of intermediate monocyte subsets to total monocytes were increased in HFRS patients compared to that in normal control, whereas no difference was found between severe/critical groups and mild/moderate groups. Phases or severity groups had no difference in ratio of non-classical monocyte subsets to total monocytes. Additionally, the ratio of classical monocyte subsets had a tendency to decline and that of intermediate monocyte subsets showed an increase both to total monocytes between the acute and convalescent phases in 11 HFRS patients with paired-samples. Moreover, in acute phase of HFRS, the mean fluorescent intensity (MFI) of CD31 on three monocyte subsets all decreased, specifically classical monocyte subsets showed the highest MFI of CD31 while the normal control reported the highest MFI of CD31 in non-classical monocyte subsets. In convalescent phase, the MFI of CD31 on classical and intermediated monocyte subsets were both lower than that of normal control, while MFI of CD31 was still significantly lower than normal control on non-classical monocyte subsets. Finally, MFI of CD31 on classical and intermediated monocyte subsets in severe/critical group were both lower than those in mild/moderate group, showing no statistical difference in MFI of CD31 on non-classical monocyte subset across groups of different disease severity. Conclusion The ratio of classical and intermediated monocyte subsets to total monocytes are correlated with the course of HFRS, and so are the surface intensity of CD31 on these monocyte subsets with the disease course and severity. The surface intensity of CD31 on non-classical monocyte subsets, however, is correlated only with the course of the disease. Together, the underlying mechanisms for the observed changes in monocyte subsets in HFRS patients should be further investigated.

Fcγ receptors on aging neutrophils

Abstract Objective Neutrophils are key effector cells of the innate immune system. They recognize antigens through membrane receptors, which are expressed during their maturation and activation. Neutrophils express FcγRII (CD32), FcγRIII (CD16), and FcγRI (CD64) after being activated by different factors such as cytokines and bacterial products. These receptors are involved with phagocytosis of IgG-opsonized microbes and enhance defense mechanisms. Based on that, our study seeks to compare the expression of FcγRII, FcγRIII, FcγRI, and CD11b on neutrophils from elderly and young subjects and their expression after in vitro activation with cytokines and LPS. Methodology Neutrophils were isolated from human peripheral blood and from mice bone marrow by density gradient. After isolation, FCγRs expression was immediately analyzed by flow cytometry or after in vitro stimulation. Results In freshly isolated cells, the percentage of FcγRIIIb+ and CD11b+ neutrophils were higher in samples from young individuals; FcγRIIIa expression was more prominent on aged neutrophils; FcγRIA expression was similar in all samples analyzed. Exposure to CXCL8 and LPS resulted in a higher percentage of FcγRIa+ neutrophils on elderly individuals' samples but lower when compared with neutrophils from young donors. We observed that LPS caused an increase in FcγRIIa expression on aging human neutrophils. In contrast, FcγRIIIb expression in response to CXCL8 and LPS stimulation was not altered in the four groups. CD11b expression was lower in neutrophils from elderly individuals even in response to LPS and CXCL8. In mice, we observed differences only regarding CD11b expression, which was increased on aged neutrophils. LPS exposure caused an increase in all FcγRs. Conclusions Our results suggest that, in humans, the overall pattern of FcγR expression and integrin CD11b are altered during aging and immunosenescence might contribute to age-related infection.

Reconstitución de células natural killer después del trasplante de células progenitoras hematopoyéticas en niños / Natural killer cell reconstitution after hematopoietic stem-cell transplantation in children

Resumen Introducción: Después de un trasplante de células progenitoras hematopoyéticas (TCPH), la reconstitución de las células natural killer (NK) es la principal barrera contra las infecciones virales. Objetivo: Determinar que el conocimiento sobre la cinética de la reconstitución de las células NK posterior al TCPH contribuye a un eficiente monitoreo del trasplante, lo que incrementa la posibilidad de éxito de este. Método: Se incluyeron 21 pacientes sometidos a TCPH, así como un grupo control de individuos clínicamente sanos. En diferentes momentos después del trasplante (intervalo de 21 a 670 días), mediante citometría de flujo se cuantificaron las células NK CD3− CD16+ CD56+ en muestras de sangre periférica. Resultados: La recuperación de las células NK ocurre entre los tres y seis meses y entre los 10 y 12 meses postrasplante; su número fue significativamente menor (en comparación con el grupo control) en el tiempo restante del monitoreo. Conclusiones: El primer periodo de recuperación de las células NK ocurre entre los tres y seis meses posteriores al trasplante. La reconstitución es transitoria y el número de células NK varía en los primeros años.

Abstract Introduction: After hematopoietic stem cell transplantation (HSCT), natural killer (NK) cells reconstitution is the main barrier against viral infections. Objective: To determine that the knowledge on the kinetics of NK cell reconstitution after HSCT contributes to transplant efficient monitoring, which increases the possibility of its success. Method: Twenty-one patients undergoing HSCT were included, as well as a control group of clinically healthy individuals. At different time points after transplantation (range of 21 to 670 days), CD3- CD16+ CD56+ NK cells were quantified by flow cytometry in peripheral blood samples. Results: NK cell recovery occurs at three to six months and 10 to 12 months post-transplantation; their number was significantly lower (in comparison with the control group) in the rest of the monitoring time. Conclusions: The first period of NK cell recovery occurs between three and six months after transplantation. Reconstitution is transient and the number of NK cells varies in the first years.

Bioinformatics analysis of programmed cell death ligand 1 co-expression genes and their regulatory network in head and neck squamous cell carcinoma / 华西口腔医学杂志

OBJECTIVE@#This study aimed to construct a network of programmed celldeath ligand 1 (PD-L1) co-expression genes and screen potential biomarkers for PD-L1 expression in head and neck squamous cell carcinoma (HNSCC) by bioinformatics analysis. Moreover, the genes and pathways participating in PD-L1 and regulating the tumor immune status were determined.@*METHODS@#The HNSCC transcriptomic dataset in TCGA was selected to retrieve gene sets on the cBioPortal platform, where PD-L1 co-expressional genes were acquired. With these genes, GO-BP, KEGG, and string analyses were performed in R clusterProfiler. Cytoscape was used for network analysis and hub gene screening.@*RESULTS@#A total of 117 co-expression genes were obtained, most of which were enriched in immune regulation and response to viral processes. Node degree analysis indicated that STAT1, IFNG, CXCL10, CCR5, FCGR3A, CXCL9, GBP5, CD86, GZMB, IRF1 were the highest connected genes and functioned as hub genes. Survival analysis of these hub genes resulted in CCR5, CXCL9, and GZMB as the prognostic biomarkers for patients with HNSCC, all of which were involved in immune regulation and their expression levels were related to PD-L1 (Pearson correlation coefficient was 0.30, 0.35, 0.39; P<0.01). High expression levels of these three hub genes were protective factors in patients with HNSCC.@*CONCLUSIONS@#PD-L1 co-expression hub genes are related to immunity, among which CCR5, CXCL9, and GZMB are prognostic markers with the possibility to be involved in programmed cell death protein 1 (PD-1)/PD-L1-induced tumor immune escape. These genes provide new clues to study the mechanism and precision target medicine of PD-1/PD-L1 in HNSCC.

Improvement of Method for Detecting Peripheral Blood Neutrophil CD64 Index in Patients with Hematologic Malignancies / 中国实验血液学杂志

OBJECTIVE@#To improve the method for detecting the neutrophil CD64 (nCD64) index and to enhance the detection rate and accuracy of nCD64 index in patients with hematologic malignancies.@*METHODS@#The nCD64 index in peripheral blood of patients with hematologic malignancies combined with suspicious bacterial infection (255 cases-time) was detected by using array method. When the detection of nCD64 index in samples was interfered with abnormal cells in detection process of enrolled patients, the antibodies CD45, CD15 and CD10 were added into samples on the basis of routine detection by using the primary detection kit, in order to more accurately distinguish the neutrphils and obtain the nCD64 index. The nCD64 index as well as the efficiency of nCD64 index, PCT and CRP for diagnosis of sepsis before and after the improvement of deteation method were compared.@*RESULTS@#The samples of 60 cases were interfered with abnormal cells in detection process, out of which the samples of 18 cases failed in detection, but these samples of 18 cases all got the effective results of detection after the detection method was improved. The detection showed that the nCD64 index before and after the improvement as well as the PCT and CRP levels in sepsis group were higher than those in non-sepsis group(P＜0.05). After improvement of method, the efficiency of nCD64 index for diagnosis of sepsis was suprior to the PCT and CRP, the nCD64 index obtained after the improvement of method possessed the diagnosis efficiency same as the efficiency obtained before improvement of method, moreover the detection results were more reliable.@*CONCLUSION@#For the samples of patients with hematologic malignancies interfered with abnormal cells in the process of detecting the nCD64 index, the corresponding antibodies are added into detected samples according to the kinds of hemotologic diseases of patients, in order to more accurately gate the neutrophils in paripheral blood of patients, there by the detection rate and accuracy for detecting the nCD64 index are enhanced by accurately distinguishing the neutrophils.

La expresión de CD64 en neutrófilos, procalcitonina y presepsina sérica son útiles para diferenciar infección de actividad en pacientes con lupus eritematoso sistémico y respuesta inflamatoria patients with systemic lupus erythematosus and inflammatory response / CD64 expression in neutrophils, Procalcitonin and serum presepsina are useful for differentiating infection activity in patients with systemic lupus erythematosus and inflammatory response

Introducción: La diferenciación entre actividad lúpica de infecciones en pacientes con lupus eritematoso sistémico (LES) es difícil debido a una presentación clínica similar. El objetivo es evaluar la utilidad de una serie de biomarcadores para diferenciar infecciones de actividad en pacientes con LES admitidos con respuesta inflamatoria sistémica (SIRS). Métodos: Pacientes con LES y SIRS que consultaron al servicio de urgencias fueron seleccionados. Se realizaron mediciones de diferentes marcadores como procalcitonina, expresión de CD64 de neutrófilos y presepsina al ingreso y fueron comparados con la presencia o no de infección, la cual se consideró presente con cultivos positivos y/o evidencia microbiológica por PCR. Se calculó la sensibilidad y especificidad de cada biomarcador y puntos de corte usando curvas ROC.

Transmembrane domain dependent inhibitory function of FcγRIIB

FcγRIIB, the only inhibitory IgG Fc receptor, functions to suppress the hyper-activation of immune cells. Numerous studies have illustrated its inhibitory function through the ITIM motif in the cytoplasmic tail of FcγRIIB. However, later studies revealed that in addition to the ITIM, the transmembrane (TM) domain of FcγRIIB is also indispensable for its inhibitory function. Indeed, recent epidemiological studies revealed that a non-synonymous single nucleotide polymorphism (rs1050501) within the TM domain of FcγRIIB, responsible for the I232T substitution, is associated with the susceptibility to systemic lupus erythematosus (SLE). In this review, we will summarize these epidemiological and functional studies of FcγRIIB-I232T in the past few years, and will further discuss the mechanisms accounting for the functional loss of FcγRIIB-I232T. Our review will help the reader gain a deeper understanding of the importance of the TM domain in mediating the inhibitory function of FcγRIIB and may provide insights to a new therapeutic target for the associated diseases.

Value of combined determination of neutrophil CD64 and procalcitonin in early diagnosis of neonatal bacterial infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the value of combined determination of neutrophil CD64 and procalcitonin (PCT) in the early diagnosis of neonatal bacterial infection.</p><p><b>METHODS</b>According to discharge diagnosis, 37 neonates with bacterial infection were divided into sepsis (n=15) and ordinary infection (non-sepsis) groups (n=22). Twenty-one neonates without infection who were hospitalized during the same period of time were enrolled as the control group. Venous blood samples were collected immediately after admission. Flow cytometry was used to measure the serum level of neutrophil CD64. Chemiluminescence and immune transmission turbidimetry were used to measure the serum levels of PCT and CRP respectively.</p><p><b>RESULTS</b>The sepsis group had higher serum levels of neutrophil CD64, PCT, and CRP than the control group (P<0.01), the ordinary infection group had a higher serum level of neutrophil CD64 than the control group (P<0.01), and the sepsis group had higher serum levels of PCT and CRP than the ordinary infection group (P<0.01). The areas under the ROC curve (AUC) of neutrophil CD64, PCT, and CRP in diagnosing bacterial infection were 0.818, 0.818, and 0.704 respectively, and the AUC of combined neutrophil CD64 and PCT was 0.926. A combination of neutrophil CD64 and PCT had a sensitivity of 97.29% and an accuracy of 89.65% in the early diagnosis of neonatal bacterial infection.The sensitivity and accuracy were higher than those of a combination of CRP and neutrophil CD64 or PCT as well as neutrophil CD64, PCT, or CRP alone for the early diagnosis of neonatal bacterial infection.</p><p><b>CONCLUSIONS</b>The combined determination of neutrophil CD64 and PCT can improve the sensitivity and accuracy in the diagnosis of neonatal bacterial infection, which helps with early identification of bacterial infection.</p>

Fc gamma receptor IIIa polymorphism is not associated with susceptibility to systemic lupus erythematosus in Brazilian patients / Polimorfismo do receptor Fc gama IIIa não está associado à susceptibilidade ao lúpus eritematoso sistêmico em pacientes brasileiros

ABSTRACT We evaluated the possible association between FCGR3A V/F (158) polymorphism and SLE susceptibility and clinical phenotype in 305 sequentially retrieved SLE patients and 300 healthy controls from the southeastern part of Brazil by allele-specific polymerase chain reaction. Our results showed no association between FCGR3A 158V/F alleles and susceptibility to SLE in this series of patients albeit the heterozygous genotype was strongly associated with the disease.

RESUMO Avaliou-se a possível associação entre o polimorfismo FCGR3A V/F (158) e a suscetibilidade e o fenótipo clínico do lúpus eritematoso sistêmico (LES) em 305 pacientes com LES admitidos sequencialmente e 300 controles saudáveis da Região Sudeste do Brasil por reação em cadeia da polimerase alelo-específica. Os resultados do presente estudo mostraram não haver associação entre os alelos FCGR3A 158 V/F e a suscetibilidade ao LES nessa série de pacientes, ainda que o genótipo heterozigoto tenha sido fortemente associado à doença.

Single Nucleotide Polymorphism rs10919543 in FCGR2A/FCGR3A Region Confers Susceptibility to Takayasu Arteritis in Chinese Population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Takayasu arteritis (TA) is a rare inflammatory arteriopathy of unknown etiology. The aim of this study was to investigate the genetic susceptibility to TA in a Chinese population.</p><p><b>METHODS</b>Four single nucleotide polymorphisms (SNPs) those locate in the IL12B region (rs56167332), the MLX region (rs665268), the FCGR2A/FCGR3A locus (rs10919543), and the HLA-B/MICA locus (rs12524487), associated with TA in different population, were genotyped in 123 Chinese TA patients and 147 healthy controls from January 2013 to August 2014. A Chi-square test was used to test for genotype/allele frequencies variants.</p><p><b>RESULTS</b>Among the four SNPs, rs10919543 was found to be significantly associated with TA in the studied population. The GG genotype of rs10919543 at the FCGR2A/FCGR3A locus is a high risk factor (odds ratio [OR] = 6.532, 95% confidence interval [CI] = 2.402 - 17.763, P < 0.001) for TA. Among TA patients, the level of eosinophil granulocytes (Eos) in the peripheral blood was observed to be higher in the GG group of rs10919543 (n = 23, Eos = 0.11 [0.08, 0.17] ×109/L) than the GA + AA group (n = 100, Eos = 0.08 [0.05, 0.13] ×109/L, P = 0.028). No correlation between the genotypes of the other three SNPs and TA patients was observed.</p><p><b>CONCLUSIONS</b>Our findings revealed unique genetic pattern in Chinese TA patients that may be partly responsible for the higher risk of TA in this population. FCGR2A/FCGR3A-related immune disorder might contribute to the etiology of TA.</p>

Neutrophil CD64 Expression as A Biomarker in the Early Diagnosis of Sepsis in Malignant Hematologic Disease--Review / 中国实验血液学杂志

Malignant hematologic disease with sepsis has been characterized by high mortality and difficulty in diagnosis at early stage. A good biomarker may help to improve the accuracy of diagnosis and to reduce the mortality rate. In the early diagnosis of sepsis, neutrophil CD64 expression is a better candidate for biomarker rather than C-reactive proteins. Moreover, neutrophil CD64 expression is also helpful for assessing the severity of infection and prognosis of disease. Unfortunately, there are few studies of neutrophil CD64 expression on the early diagnosis of malignant hematologic diseases. This review focuses on the advantages, limitations, feasibilities and progresses of neutrophil CD64 expression in the early diagnosis of infection in malignant hematologic diseases in this paper.

Analysis of single nucleotide polymorphisms and haplotypes of FCGR2A gene among patients with ulcerative colitis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association of several single nucleotide polymorphisms and haplotypes of the FCGR2A gene with ulcerative colitis (UC) among Chinese patients.</p><p><b>METHODS</b>For 198 UC patients and 356 healthy controls, the alleles and genotypes of the FCGR2A gene (rs1801274, rs10800309 and rs6696854) were detected with a multiplex SNaPshot technique. All subjects were also subjected to linkage disequilibrium and haplotype analyses.</p><p><b>RESULTS</b>The mutant homozygote (CC) of the FCGR2A gene rs1801274 polymorphism was less frequent among UC patients compared with the controls (5.56% vs. 11.80%, P=0.017, OR=0.440, 95%CI: 0.221-0.875). However, the allelic and genotypic distributions of other two SNPs did not differ significantly between the two groups (all P>0.05). Furthermore, no association of the three SNPs (rs1801274, rs10800309 and rs6696854) of the FCGR2A gene with the severity and location of the UC was found (all P>0.05). The three SNPs were shown to be in a strong linkage [rs1801274-rs10800309 (D'=0.863, r=0.634); rs1801274-rs6696854 (D'=0.753, r=0.546); rs10800309-rs6696854(D'=0.990, r=0.802)]. Moreover, the frequency of T-A-T haplotype was higher among the UC patients compared with the controls (67.40% vs. 60.93%, P=0.032, OR=1.326, 95%CI: 1.024-1.717).</p><p><b>CONCLUSION</b>Our findings suggested that the mutant homozygote (CC) of the FCGR2A gene (rs1801274) may have a protective role among Chinese patients with UC. Moreover, the T-A-T haplotype formed by rs1801274, rs10800309 and rs6696854 may confer a higher risk for UC.</p>

Diagnostic values of plasma CD64 and sTREM-1 for pediatric pneumonia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To determine the diagnostic values of plasma CD64 and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in children with pneumonia.</p><p><b>METHODS</b>Sixty children with pneumonia between August 2014 and October 2015 were classified into bacterial pneumonia group (25 cases), viral pneumonia group (17 cases), and Mycoplasma pneumonia group (18 cases) according to their clinical manifestations, pathogen cultures, and X-ray findings. Another 30 healthy children who underwent physical examination during the same period were selected as the control group. The concentrations of CD64 and sTREM-1 in blood samples were determined using ELISA. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic sensitivity and specificity of plasma CD64 and/or sTREM-1 for bacterial pneumonia.</p><p><b>RESULTS</b>The expression of CD64 and sTREM-1 in the bacterial pneumonia group was significantly higher than that in the viral pneumonia, Mycoplasma pneumonia, and control groups (P<0.05). The areas under the ROC curves of CD64, sTREM-1, and a combination of the two markers for diagnosing bacterial pneumonia were 0.878, 0.805, and 0.956, respectively. The sensitivity and specificity of CD64 for diagnosing bacterial pneumonia were 81.30% and 92.32%, respectively, when the cut-off value was 641 pg/mL. The sensitivity and specificity of sTREM-1 for diagnosing bacterial pneumonia were 78.65% and 84.67%, respectively, when the cut-off value was 1 479 pg/mL. The sensitivity and specificity of a combination of the two markers for diagnosing bacterial pneumonia were 93.15% and 91.54%, respectively.</p><p><b>CONCLUSIONS</b>Plasma CD64 and sTREM-1 can be used as markers for diagnosing pediatric bacterial pneumonia, and a combination of the two markers results in better diagnosis.</p>

Could CD64 expression be used as a predictor of positive culture results in children with febrile neutropenia?

Background: Early recognition of infectious processes in neutropenic patients is hampered by the fact that these processes may have dissimilar and non-specific clinical presentations. CD64 is a neutrophil surface marker that is not expressed in non-sensitized neutrophils. When the neutrophil is exposed to tumor necrosis factor-alpha it is activated and is measured via the CD64 index. Methods: This paper evaluated the relationship between the index value of CD64 on the first day of febrile neutropenia and a positive blood culture. The correlations with white blood count, C-reactive protein and erythrocyte sedimentation rate were also evaluated. This case-control, prospective, diagnostic study included 64 episodes of neutropenia. Case group (n = 14) comprised positive blood cultures, and the control group (n = 50), negative blood cultures. Results: The median rates of CD64 were 2.1 (a ± 3.9) in the case group and 1.76 (a ± 5.02) in the control group. There was no correlation between the value of the CD64 index and blood cultures. The CD64 index was also not correlated with C-reactive protein positivity. Further- more, the CD64 index was not able to predict blood culture positivity. The sensitivity was 64.3%, the specificity was 42%, the positive predictive value was 23.7% and the negative predictive value was 80%. For C-reactive protein, the sensitivity, specificity, positive predictive value, and negative predictive value were 71.4%, 32%, 22.7%, and 80%, respectively. Conclusion: The CD64 index is not suitable for predicting the positivity of blood cultures in this specific population of patients with febrile neutropenia.

Identificação de peptídeos de Escherichia coli capazes de inibir a própria fagocitose em sepse / Identification of Escherichia coli peptides that can inhibit its own phagocytosis in sepsis

Introdução: Sepse é uma síndrome complexa definida por resposta inflamatória sistêmica, de origem infecciosa e caracterizada por manifestações múltiplas que podem determinar disfunção ou falência de um ou mais órgãos ou sistemas. É a principal causa de morte em unidades de terapia intensiva em pacientes críticos e tem representado uma fonte constante de preocupação para os sistemas de saúde em todo o mundo, devido, principalmente, às taxas elevadas de morbimortalidade. O tratamento da sepse é um desafio e continua a ser uma tarefa difícil devido a inúmeros fatores interferentes. Um estudo do nosso grupo demonstrou que a Escherichia coli (E. coli) é capaz de se ligar CD16 de um modo independente de opsonina, levando a um aumento na resposta inflamatória e a inibição da sua própria fagocitose, por conseguinte, procurou-se identificar os peptídeos no proteoma da E. coli envolvidos neste cenário. Metodologia: Utilizando a metodologia de Phage Display, que consiste numa técnica de clonagem, que permite a expressão de diversas sequências de peptídeos na superfície de bacteriófagos, nós identificamos 2 peptídeos que obtiveram interação com CD16. Após a seleção dos peptídeos identificamos uma proteína de membrana de E.coli que possui alta similaridade com um de nossos peptídeos selecionados. Nós acreditamos que esta proteína de membrana possa estar envolvida no processo de evasão imune desenvolvida pela E.coli e parece ser um forte candidato como uma nova opção terapêutica para controlar infecções por E. coli. Conclusão: A identificação de proteínas capazes de induzir inibição de fagocitose, através do receptor CD16, pode ser usada como uma nova forma de tratamento da sepse, assim como explorada no tratamento de doenças autoimunes.

Introduction: Sepsis is a complex syndrome defined by a systemic inflammatory response of infectious origin and characterized by multiple manifestations that can determine dysfunction/failure of one or more organs and systems. It is the leading cause of death in intensive care units and represents a major health problem around the world, mainly due to its high mortality and morbidity rates. The treatment of sepsis is challenging and remains a difficult task due to numerous interfering factors. A study from our group demonstrated that Escherichia coli (E. coli) is able to bind CD16 in an opsoninindependent manner, leading to an increase in the inflammatory response and inhibition of its own phagocytosis, therefore we sought to identify the peptides in the E. coli proteome involved in this scenario. Methods and Results: Using the Phage Display technique, which is a cloning technique that allows the expression of various peptide sequences on the surface of bacteriophages (phages) and selecting these on the basis of affinity for a target molecule, we identified two peptides that interact with CD16. Next, using bioinformatic tools, we found an E. coli membrane protein that has high similarity with one of our selected peptides. We believe this membrane protein is involved in the process of immune evasion developed by E. coli and it is a strong candidate as a new therapeutic option to control E. coli infections. Conclusion: The identification of proteins capable of inducing inhibition of phagocytosis through the CD16 receptor, can be used as a new treatment of sepsis, as well as exploited in the treatment of autoimmune diseases.

Progress of molecular genetics research on rheumatoid arthritis / 中华医学遗传学杂志

Rheumatoid arthritis (RA) is a chronic, inflammatory, autoimmune disorder that principally attacks flexible joints and synovia. The precise pathogenesis of RA remains unclear, and genetic factors probably play an important role in its etiology. In addition to genes from human leukocyte antigen (HLA) region, such as HLA-DRB, genes from non-HLA region, such as TIM-3, PTPN22, TRAF1/C5, STAT4, CCR5, PADI4 and FCGR2A may also contribute to its susceptibility. The advance in molecular genetics research on RA is reviewed here.

Effect of FCGR3A Polymorphisms on Antibody-dependent Cetuximab-mediated Cytotoxicity in A549 Cells / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of FCGR3A polymorphisms on the antibody-dependent cell-mediated cytotoxicity (ADCC) activity induced by cetuximab against A549 cells.</p><p><b>METHODS</b>A549 cell line was used as target cells and NKTm cells as effector cells. FCGR3A polymorphisms were detected by direct sequencing. The ADCC activity mediated by cetuximab was assessed by CCK-8 assay.</p><p><b>RESULTS</b>Three genotypes of FCGR3A were detected:V/V,V/F,and F/F. The ADCC activity of NKTm cells with these three different genotypes mediated by cetuximab were significantly different (P=0.0015). NKTm cells with FCGR3A-158V/V genotypes had significantly higher ADCC activity than FCGR3A-V/F or F/F genotypes (P<0.01),whereas the ADCC activity between V/F and F/F genotype showed no statistical significance(P>0.05).</p><p><b>CONCLUSION</b>FCGR3A polymorphisms have an impact on ADCC activity mediated by cetuximab in NKTm cells.</p>

Diagnostic Value of Neutrophil CD64 for Bacterial Infection in Patients with Hematologic Malignancies after Chemotherapy / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the value of CD64 mean fluorescence intensity of the peripheral blood neutrophils as a diagnostic marker of bacterial infection in patients with hematologic malignancies after chemotherapy.</p><p><b>METHODS</b>The neutrophil CD64 mean fluorescence intensity of all patients was detected by flow cytometry, and compared with procalcitonin (PCT) and C reactive protein (CRP) detected in part of patients; the relationship between nCD64 and bacterial infection were analyzed through continuous dynamic monitoring nCD64 mean fluorescence intensity in part of patients.</p><p><b>RESULTS</b>The expression of nCD64 was not affected by neutrophils counts (P>0.01); the nCD64 mean fluorescence intensity, PCT and CRP levels in infection group and dynamic monitoring group were significantly higher than those in non-infected group (P<0.01); the sensitivity and specificity of nCD64 mean fluorescence intensity were much higher, as compared with PCT and CRP in diagnosis of bacterial infection.</p><p><b>CONCLUSION</b>nCD64 mean fluorescence intensity can be used as an effective diagnostic marker for bacterial infection in patients with hematologic malignancies after chemotherapy, and may be used to forecast bacterial infection to a certain extent.</p>