ABSTRACT
Abstract | Introduction: It is essential to determine the interactions between viruses and mosquitoes to diminish dengue viral transmission. These interactions constitute a very complex system of highly regulated pathways known as the innate immune system of the mosquito, which produces antimicrobial peptides that act as effector molecules against bacterial and fungal infections. There is less information about such effects on virus infections. Objective: To determine the expression of two antimicrobial peptide genes, defensin A and cecropin A, in Aedes aegypti mosquitoes infected with DENV-1. Materials and methods: We used the F1 generation of mosquitoes orally infected with DENV-1 and real-time PCR analysis to determine whether the defensin A and cecropin A genes played a role in controlling DENV-1 replication in Ae. aegypti. As a reference, we conducted similar experiments with the bacteria Escherichia coli. Results: Basal levels of defensin A and cecropin A mRNA were expressed in uninfected mosquitoes at different times post-blood feeding. The infected mosquitoes experienced reduced expression of these mRNA by at least eightfold when compared to uninfected control mosquitoes at all times post-infection. In contrast with the behavior of DENV-1, results showed that bacterial infection produced up-regulation of defensin and cecropin genes; however, the induction of transcripts occurred at later times (15 days). Conclusion: DENV-1 virus inhibited the expression of defensin A and cecropin A genes in a wild Ae. aegypti population from Venezuela.
Resumen | Introducción. Es esencial determinar las interacciones entre los virus y los mosquitos para disminuir la transmisión viral. Estas interacciones constituyen un sistema muy complejo y muy regulado conocido como sistema inmunitario innato del mosquito, el cual produce péptidos antimicrobianos, moléculas efectoras que funcionan contra las infecciones bacterianas y fúngicas; se tiene poca información de su acción sobre los virus. Objetivo. Determinar la expresión de dos genes AMP (defensina A y cecropina A) en mosquitos Aedes aegypti infectados con el virus DENV-1. Materiales y métodos. Se infectaron oralmente mosquitos de generación F1 con DENV-1 y mediante el análisis con PCR en tiempo real se determinó el potencial papel de los genes defensina A y cecropina A en el control de la replicación del DENV-1 en Ae. aegypti. Como referencia, se infectaron mosquitos con Escherichia coli. Resultados: Los mosquitos no infectados expresaron niveles basales de los ARNm de los genes defensina A y cecropina A en diversos momentos después de la alimentación. Los mosquitos infectados experimentaron una reducción, por lo menos, de ocho veces en la expresión de estos ARNm con respecto a los mosquitos de control en todo el periodo posterior a la alimentación. En contraste con el comportamiento del virus DENV-1, los resultados mostraron que la infección bacteriana produjo una regulación positiva de los genes defensina y cecropina; sin embargo, la inducción de los transcritos ocurrió tardíamente (15 días). Conclusión. El virus DENV-1 inhibió la expresión de los genes defensina A y cecropina A en una población silvestre de Ae. aegypti en Venezuela.
Subject(s)
Aedes , Dengue Virus , alpha-Defensins , Escherichia coli , CecropinsABSTRACT
Objective To evaluate the feasibility of developing hospital acquired pneumonia (HAP) risk warning model in critically ill patients based on genomic copy number polymorphisms (CNPs) of the genes encoding human neutrophil peptides 1-3 (DEFA1/DEFA3).Methods Seventy-seven HAP patients (group HAP) and 109 non-HAP patients of matched age and sex in intensive care unit (ICU) (group NHAP) were enrolled in the study.The genomic CNPs of DEFA1/DEFA3 was determined by realtime quantitative polymerase chain reaction after extracting DNA from peripheral blood samples.The source of patients,condition of endotracheal intubation within 24 h after admission to ICU,Acute Physiology Score,Acute Physiology and Chronic Health Evaluation Ⅱ score,Sequential Organ Failure Assessment score,mechanical ventilation time,length of hospital and ICU stay and outcomes were obtained.The predictive model was developed using logistic regression through combining DEFA1/DEFA3 copy numbers and clinical characteristics (Acute Physiology Score and source of emergency) within 24 h after admission to ICU.The receiver operating characteristic curve was used to evaluate the predictive efficacy of the model.Results The copy numbers of DEFA1/DEFA3 were significantly lower in HAP group than in NHAP group (P ＜0.05).The area under the receiver operating characteristic curve of the predictive model developed through combining the DEFA1/DEFA3 copy numbers with clinical characteristics was 0.789 (95％ CI 0.724-0.854) when the model was used for predicting HAP.Conclusion CNPs of DEFA1/DEFA3 can be used to develop the HAP risk warning model in critically ill patients.
ABSTRACT
Objective To investigate the profile of local immunity of vagina and the immune defense mechanisms against lower genital tract infections. Methods Vaginal lavage was collected from healthy women and patients of vulvovaginal candidiasis, bacterial vaginosis, Trichomonol vaginitis, human papilloma virus infection(VVC), and chlamydia trachomatis infection. Each group included 60 cases. The level of interleukin (IL) 2,4,5, 13,8 and human defensin 5 (HD5) were detected by enzyme linked immunosorbent assay(ELISA). Results (1) Cytokine of helper T cell 1(Th1): the level of IL-2 between healthy women and VVC/ bacterial vaginosis (BV)/ trichomonol vaginitis (TV)/ chlamydia trachomatis (CT) patients had no significant difference. The IL-2 level(96±33 )×10-3 pg/L of human papilloma virus (HPV) infection patients was significantly higher than that of healthy women( P<0.05). (2)Cytokine of helper T cell 2 (Th2) : the level of IL-4 between healthy women and VVC/CT patients had no significant difference. The level of IL-5 between healthy women and BV patients had no significant difference. The IL-13 level(42±15)×10-3 pg/L of TV patients was significantly higher than that of healthy women (30±29)×10-3 pg/L (P<0.05). The IL-4 level (103±28)×10-3 pg/L of HPV infection patients was significantly higher than that of healthy women (36±22)×10-3 pg/L (P<0. 05 ). (3) IL-8 : the IL-8 level (5.8± 2.7) pg/L of TV infection patients was significantly higher than that of healthy women (2. 6±2.4) pg/L (P<0.05). The level of IL-8 between healthy women and BV patients had no significant difference. (4)HD5:the HD5 level of TV , BV, VVC, HPV and CT infection patients were significantly higher than that of healthy women (P<0.05). Conclusions (1) HD5 plays an important role in the defence of vaginal epithelial cell. (2) Th2 may be more important than Thl in lower genital tract infections.(3) IL-8 plays an important role in extrinsic source infections.