RESUMEN
BACKGROUND: Human papillomavirus (HPV) type 16 accounts for a larger share of cervical cancer and has been a major health problem worldwide for decades. The progression of initial infection to cervical cancer has been linked to viral sequence properties; however, the role of HPV16 variants in the risk of cervical carcinogenesis, especially with longitudinal follow-up, is not fully understood in China. METHODS: We aimed to investigate the genetic variability of HPV16 E6 and E7 oncogenes in isolates from cervical exfoliated cells. Between December 2012 and December 2014, a total of 310 single HPV16-positive samples were selected from women living in the Taizhou area, China. Sequences of all E6 and E7 oncogenes were analysed by PCR-sequencing assay. Detailed sequence comparison, genetic heterogeneity analyses and maximum-likelihood phylogenetic tree construction were performed with BioEdit Sequence Alignment Editor and MEGA X software. Data for cytology tests and histological diagnoses were obtained from our Taizhou Area Study with longitudinal follow-up for at least 5 years. The relationship between HPV16 variants and cervical carcinogenesis risk was analysed by the chi-square test or Fisher's exact test. RESULTS: In this study, we obtained 64 distinct variation patterns with the accession GenBank numbers MT681266-MT681329. Phylogenetic analysis revealed that 98.3% of HPV16 variants belong to lineage A, in which the A4 (Asian) sublineage was dominant (64.8%), followed by A2 (12.1%), A1 (11.4%), and A3 (10.0%). The A4 (Asian) sublineage had a higher risk of CIN2+ than the A1-3 (European) sublineages (OR = 2.69, 95% CI = 1.04-6.97, P < 0.05). Furthermore, nucleotide variation in HPV16 E6 T178G is associated with the development of cervical cancer. CONCLUSION: These data could provide novel insights into the role of HPV16 variants in cervical carcinogenesis risk in China.
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Variación Genética/genética , Papillomavirus Humano 16/genética , Proteínas Oncogénicas Virales/metabolismo , Proteínas Represoras/metabolismo , Neoplasias del Cuello Uterino/genética , Adulto , Anciano , China , Femenino , Humanos , Persona de Mediana Edad , Mutación , Neoplasias del Cuello Uterino/patología , Adulto JovenRESUMEN
OBJECTIVE: To investigate the associations between epidermal growth factor receptor (EGFR) gene mutations and serum tumor markers in advanced lung adenocarcinomas. METHODS: We investigated the association between EGFR gene mutations and clinical features, including serum tumor marker levels, in 97 advanced lung adenocarcinomas patients who did not undergo the treatment of EGFR tyrosine kinase inhibitors. EGFR gene mutation was detected by real-time PCR at exons 18, 19, 20, and 21. Serum tumor marker concentrations were analyzed by chemiluminescence assay kit at the same time. RESULTS: EGFR gene mutations were detected in 42 (43%) advanced lung adenocarcinoma patients. Gender (P=0.003), smoking status (P=0.001), and abnormal serum status of carcinoembryonic antigen (CEA, P=0.028) were significantly associated with EGFR gene mutation incidence. Multivariate analysis showed the abnormal CEA level in serum was independently associated with the incidence of EGFR gene mutation (P=0.046) with an odds ratio of 2.613 (95% CI: 1.018-6.710). However, receiver operating characteristic (ROC) curve analysis revealed CEA was not an ideal predictive marker for EGFR gene mutation status in advanced lung adenocarcinoma (the area under the ROC curve was 0.608, P=0.069). CONCLUSIONS: EGFR gene mutation status is significantly associated with serum CEA status in advanced lung adenocarcinmoas. However, serum CEA is not an ideal predictor for EGFR mutation.
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Adenocarcinoma/genética , Biomarcadores de Tumor/sangre , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Mutación , Adenocarcinoma/sangre , Femenino , Humanos , Neoplasias Pulmonares/sangre , Masculino , Persona de Mediana Edad , Curva ROC , Reacción en Cadena en Tiempo Real de la Polimerasa , Estudios RetrospectivosRESUMEN
BACKGROUND: Xq22.1-q22.3 deletion is a rare chromosome aberration. The purpose of this study was to identify the correlation between the phenotype and genotype of chromosome Xq22.1-q22.3 deletions. METHODS: Chromosome aberrations were identified by copy number variation sequencing (CNV-seq) technology and karyotype analysis. Furthermore, we reviewed patients with Xq22.1-q22.3 deletions or a deletion partially overlapping this region to highlight the rare condition and analyse the genotype-phenotype correlations. RESULTS: We described a female foetus who is the "proband" of a Chinese pedigree and carries a heterozygous 5.29 Mb deletion (GRCh37: chrX: 100,460,000-105,740,000) in chromosome Xq22.1-q22.3, which may affect 98 genes from DRP2 to NAP1L4P2. This deletion encompasses 7 known morbid genes: TIMM8A, BTK, GLA, HNRNPH2, GPRASP2, PLP1, and SERPINA7. In addition, the parents have a normal phenotype and are of normal intelligence. The paternal genotype is normal. The mother carries the same deletion in the X chromosome. These results indicate that the foetus inherited this CNV from her mother. Moreover, two more healthy female family members were identified to carry the same CNV deletion through pedigree analysis according to the next-generation sequencing (NGS) results. To our knowledge, this family is the first pedigree to have the largest reported deletion of Xq22.1-q22.3 but to have a normal phenotype with normal intelligence. CONCLUSIONS: Our findings further improve the understanding of the genotype-phenotype correlations of chromosome Xq22.1-q22.3 deletions.This report may provide novel information for prenatal diagnosis and genetic counselling for patients who carry similar chromosome abnormalities.
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Aberraciones Cromosómicas , Variaciones en el Número de Copia de ADN , Embarazo , Femenino , Humanos , Linaje , Fenotipo , Deleción Cromosómica , Cromosomas , Proteínas del Complejo de Importación de Proteínas Precursoras MitocondrialesRESUMEN
BACKGROUND: Non-invasive prenatal testing (NIPT) has been established as a routine prenatal screening to assess the risk of common foetal aneuploidy disorder (trisomy 21, 18, and 13). NIPT has high sensitivity and high specificity, but false positive and false negative results still exist. False negative NIPT results involving Down syndrome are rare, but have a high clinical impact on families and society. CASE PRESENTATION: We described a case of a foetus that tested "negative" for trisomy 21 (Z-score was 0.664) by NIPT based on the semiconductor sequencing platform (SSP). The foetal fraction of cell-free DNA was 16.9%; this percentage was much larger than the threshold of 4% for obtaining accurate NIPT results. However, postnatally, the newborn was diagnosed with Down syndrome with the 46,XY,der(21;21)(q10;q10),+ 21 karyotype. CONCLUSIONS: We presented a case of false negative NIPT results, which may occur through biological mechanisms rather than poor quality, technical errors or negligence. It is imperative for clinical geneticists and their patients to understand that NIPT is still a screening test.
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Ácidos Nucleicos Libres de Células/genética , Cromosomas Humanos Par 21/genética , Síndrome de Down/diagnóstico , Feto/metabolismo , Reordenamiento Génico , Diagnóstico Prenatal/métodos , Trisomía , Adulto , Ácidos Nucleicos Libres de Células/análisis , Síndrome de Down/genética , Reacciones Falso Negativas , Femenino , Humanos , Recién Nacido , Masculino , EmbarazoRESUMEN
It is well recognized that the association of human papillomavirus (HPV) and cervical carcinogenesis is based on the presence of HPV DNA sequence. The E6 and E7 oncoproteins encoded by high-risk HPV types play a key role in carcinogenesis. HPV58 type accounts for a larger share of cervical disease in China, whereas data on HPV58 genetic variability in China is limited. We aimed to evaluate the diversity of HPV58 genetic variants by sequencing the entire E6 and E7 genes. Phylogenetic trees were constructed by Maximum likelihood method by MEGA 5.05 software. In this study, the overall HPV infection rate was 22.6% (2891/12780) in Southeast China and the prevalence of HPV58 infection rate was 2.6% (335/12780). 26 nucleotides substitutions were observed in E6 and E7 genes with 10 novel substitutions and 17 non-synonymous substitutions. We obtained 25 distinct variation patterns which the accession GenBank numbers as MH348918-MH348942. All of HPV58 variants belong to lineage A, while no lineage B, C and D were detected in Taizhou area, Southeast China. The sublineage A1, A2, and A3 variants were found in 136 (68.3%), 39 (19.6%), and 24 (12.1%) of HPV58 isolates, respectively. The sublineage A3 variants with T20I/G63S substitutions at E7 oncoprotein carried a significantly higher risk for high-grade cervical intraepithelial neoplasia (CIN2 or worse, CIN2+) when compared with other HPV58 variants (odds ratioâ¯=â¯4.41, Pâ¯<â¯0.05). Nevertheless, there was no association between HPV58 (sub) lineages and cervical lesions. These data provide the critical characteristics of HPV58 variants to assist further investigation of carcinogenic association and the development of next generation vaccines and diagnostic assays in China.
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Alphapapillomavirus , Proteínas Oncogénicas Virales/genética , Infecciones por Papillomavirus/genética , Filogenia , Neoplasias del Cuello Uterino/genética , Adolescente , Adulto , Anciano , Alphapapillomavirus/clasificación , Alphapapillomavirus/genética , China/epidemiología , Femenino , Humanos , Persona de Mediana Edad , Prevalencia , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/virologíaRESUMEN
OBJECTIVES: High-risk human papillomaviruses (hrHPVs) are highly prevalent worldwide, and HPV genotypes differ between geographical regions; however, sexually transmitted HPV may lead to cervical carcinogenesis. The objective of this cross-sectional study was to estimate the prevalence characteristics of cervical HPV genotypes in Taizhou, Southeast China. SETTING AND PARTICIPANTS: A population-based sample of 37 967 eligible women (median age: 41.6; range: 15-90 years) visiting the Taizhou ENZE Medical Center in Taizhou (2012-2016) was analysed. HPV genotyping was performed on the collected specimens using a GP5+/bioGP6+-PCR/MPG assay by Luminex 200, which simultaneously identifies 27 different HPV genotypes and the ß-globin gene (internal control). RESULTS: The overall HPV infection rate was 22.8% in the Taizhou-based population, and the prevalence of high-risk HPV, low-risk HPV and mixed high-risk and low-risk HPV infection was 14.2%, 5.7% and 3.0%, respectively. The most prevalent genotypes were HPV52 (19.7%), 16 (11.9%), 58 (11.5%), 39 (7.2%), 18 (6.6%) and 56 (5.6%). The rate of multiple-type HPV infection was 5.7% in the whole population, and the HPV52+58, HPV16+52 and HPV16+18 mixed genotypes were most common in women with multiple infections. The age-specific HPV prevalence showed a bimodal curve, with a first peak below the age of 21 years (41.6%), followed by a second peak in the age group of 56-60 years (28.5%). Moreover, the HPV infection rate differed significantly between the outpatient and physical examination groups (24.0% vs 19.5%, p<0.0001). Further data comparisons showed that the distribution of HPV genotypes varied markedly between the two groups. CONCLUSIONS: Data from this study could be valuable for HPV-based cervical cancer screening efforts in certain areas, support the local vaccination programme in the Taizhou region and facilitate future diagnosis and treatment of HPV diseases.
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Coinfección/epidemiología , Papillomaviridae/genética , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Atención Ambulatoria/estadística & datos numéricos , China/epidemiología , Coinfección/virología , Estudios Transversales , Femenino , Genotipo , Humanos , Persona de Mediana Edad , Examen Físico/estadística & datos numéricos , Prevalencia , Adulto JovenRESUMEN
DC-10 is a distinct subset of human tolerogenic dendritic cells (DCs) which express high levels of human leukocyte antigen-G (HLA-G). DC-10 could induce adaptive type 1 regulatory T cells through the IL-10 dependent ILT4/HLA-G signaling pathway. However, the significance of DC-10 in malignancies remains unclear. In this study, the frequency and mean fluorescence intensity (MFI) of HLA-G+ DC-10 in the peripheral blood of 124 patients with gastric cancer (GC) and 130 normal controls was analyzed with flow cytometry. Plasma sHLA-G was analyzed with ELISA. Results showed both the percentages of peripheral HLA-G+ DC-10 (median: 0.13% vs 0.01%; p<0.01) and MFI of HLA-G on these cells (median: 310.0 vs 91.5; p<0.01) were dramatically increased in GC patients than in normal controls. The frequency of HLA-G+ DC-10 in GC patients was strongly relative to the tumor grade (p=0.021). sHLA-G levels in GC patients were significantly higher than in healthy controls (median: 85.80U/ml vs 61.20U/ml; p<0.01). There was no significant correlation between the percentage of DC-10 and plasma sHLA-G (p>0.05). However, the increased HLA-G+ DC-10, HLA-G MFI and plasma sHLA-G in patients with gastric cancer could be a diagnostic factor with the area under the ROC curve with 0.947 (p<0.01), 0.882 (p<0.01) and 0.700 (p<0.01) respectively. Given the immune tolerant function of DC-10 could play, the increased DC-10 might play an important role in immune suppression for patients with gastric cancer, while more studies are necessary to illustrate the clinical relevance of DC-10 in cancer patients.
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Proteínas Sanguíneas/metabolismo , Células Dendríticas/metabolismo , Antígenos HLA-G/metabolismo , Neoplasias Gástricas/inmunología , Linfocitos T Reguladores/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Recuento de Células , Separación Celular , Células Dendríticas/patología , Femenino , Citometría de Flujo , Humanos , Tolerancia Inmunológica , Interleucina-10/metabolismo , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Gástricas/patologíaRESUMEN
BACKGROUND: Previous observational studies regarding the existence of an association between folate intake and the risk of breast cancer have been inconsistent. This study aimed to summarize the evidence regarding this relationship using a dose-response meta-analytic approach. METHODOLOGY AND PRINCIPAL FINDINGS: We performed electronic searches of the PubMed, EmBase, and Cochrane Library databases to identify studies published through June 2013. Only prospective observational studies that reported breast cancer effect estimates with 95% confidence intervals (CIs) for more than 2 folate intake categories were included. We excluded traditional case-control studies because of possible bias from various confounding factors. Overall, we included 14 prospective studies that reported data on 677,858 individuals. Folate intake had little effect on the breast cancer risk (relative risk (RR) for highest versus lowest categoryâ=â0.97; 95% CI, 0.90-1.05; Pâ=â0.451). Dose-response meta-analysis also suggested that a 100 µg/day increase in folate intake had no significant effect on the risk of breast cancer (RRâ=â0.99; 95% CI, 0.98-1.01; Pâ=â0.361). Furthermore, we used restricted cubic splines to evaluate the nonlinear relationship between folate intake and the risk of breast cancer, and discovered a potential J-shaped correlation between folate intake and breast cancer risk (Pâ=â0.007) and revealed that a daily folate intake of 200-320 µg was associated with a lower breast cancer risk; however, the breast cancer risk increased significantly with a daily folate intake >400 µg. CONCLUSION/SIGNIFICANCE: Our study revealed that folate intake had little or no effect on the risk of breast cancer; moreover, a dose-response meta-analysis suggested a J-shaped association between folate intake and breast cancer.
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Neoplasias de la Mama/etiología , Ácido Fólico/administración & dosificación , Complejo Vitamínico B/administración & dosificación , Relación Dosis-Respuesta a Droga , Femenino , Ácido Fólico/efectos adversos , Humanos , Estudios Observacionales como Asunto , Estudios Prospectivos , Factores de Riesgo , Complejo Vitamínico B/efectos adversosRESUMEN
A novel H1N1 virus of swine origin (H1N1v) recently caused a pandemic; however, knowledge of immunologic aspects of the virus infection are limited. Human leukocyte antigen-G (HLA-G) was speculated to play critical roles in viral infection, although its clinical relevance in H1N1 infection remains unknown. In this study, HLA-G expression in peripheral T lymphocytes, monocytes, and CD4(+) CD25(+) FoxP3+ regulatory T (Treg) cells (in 50 H1N1v-infected and 41 seasonal H1N1-infected patients and 27 control subjects) were analyzed by flow cytometry. Plasma-soluble HLA-G (sHLA-G, in 28 H1N1v-infected, 29 seasonal H1N1-infected patients and 85 control subjects) were determined with enzyme-linked immunosorbent assay. The percentage of HLA-G-positive T lymphocytes and monocytes among patients with H1N1v and seasonal H1N1 infections was dramatically increased compared with controls (all p < 0.001). Treg was markedly increased among H1N1v- infected patients compared with normal controls (p = 0.041), but not for the seasonal H1N1-infected patients. Meanwhile, no significant difference was observed for sHLA-G levels between the groups. Together, cell surface HLA-G expression was markedly induced in H1N1v-infected and seasonal H1N1-infected patients, and increased Treg was observed only in H1N1v-infected patients. Given its immune-suppressive property, elevated cell surface HLA-G expression may help to explain the virus escaping from host immune responses.
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Antígenos HLA/genética , Antígenos HLA/inmunología , Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/inmunología , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/sangre , Gripe Humana/inmunología , Monocitos/inmunología , Linfocitos T Reguladores/inmunología , Adolescente , Estudios de Casos y Controles , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Expresión Génica , Antígenos HLA/sangre , Antígenos HLA-G , Antígenos de Histocompatibilidad Clase I/sangre , Humanos , Evasión Inmune , Subtipo H1N1 del Virus de la Influenza A/fisiología , Gripe Humana/virología , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Recuento de Linfocitos , Masculino , Monocitos/metabolismo , Pandemias , Linfocitos T Reguladores/metabolismo , Replicación Viral , Adulto JovenRESUMEN
OBJECTIVE: To investigate the effects of anti-CD44 mAb A3D8 on the cell proliferation of human acute monocytic leukemia cell line THP-1 and its mechanism. METHODS: Cell proliferation was assayed with MTT method, the expression of CD33, CD15, CD11b, CD14, Annexin-V, caspase-3 and cell cycle with flow cytometry, and the expression of p-Akt, p-ERK, bcl-2 and p27kip1 with Western blot. RESULTS: A3D8 could remarkably inhibit the proliferation capacity of the THP-1 cells in a dosage- and time-dependent manner. THP-1 differentiation was observed when treated with A3D8 (2.0 µg/ml) for one to six days. Expression of CD33 (68.9 ± 2.0 vs 39.3 ± 1.5), CD15 (61.7 ± 5.5 vs 12.9 ± 2.6), CD11b (67.3 ± 3.8 vs 14.0 ± 2.0) and CD14 (83.0 ± 5.7 vs 8.0 ± 1.0) was significantly increased at day 4 compared with the control group (all P < 0.01). Cell cycle of the THP-1 cells was arrested in G(0)/G(1). Expression of the Annexin-V \[(32.5 ± 2.5)% vs (2.4 ± 0.3)%\] and caspase-3 \[(33.3 ± 2.5)% vs (3.6 ± 0.3)%\] was much higher than that in normal controls (all P < 0.01), and apoptosis was observed in THP-1 cells at day 5. Expression of p-Akt (0.24 ± 0.06 vs 1.20 ± 0.15), p-ERK (0.32 ± 0.05 vs 1.24 ± 0.09), and bcl-2 (0.11 ± 0.05 vs 0.65 ± 0.07) was much lower than that of the controls (all P < 0.01), while p27kip1 (1.08 ± 0.09 vs 0.10 ± 0.02) was significantly increased at day 4 (P < 0.05). CONCLUSION: Anti-CD44 antibody can induce the differentiation and apoptosis of THP-1 cell through inhibiting PI3K/AKt and ERK1/2 signaling pathway.
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Anticuerpos Monoclonales/farmacología , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Anticuerpos Monoclonales/inmunología , Línea Celular Tumoral , Humanos , Receptores de Hialuranos/inmunología , Leucemia Monocítica Aguda/patología , Transducción de SeñalRESUMEN
The significance of upregulated soluble human leukocyte antigen-G (sHLA-G) expression under various pathologic conditions has been discussed. In this study, we evaluated the potential significance of plasma sHLA-G expression in patients with hepatitis B virus (HBV) infection. The study included 90 acute hepatitis B patients (AHB), 131 chronic hepatitis B patients (CHB), 152 resolved hepatitis B individuals (RHB), and 129 normal controls. sHLA-G were determined using enzyme-linked immunosorbent assay. A receiver operating characteristic (ROC) curve was used to evaluate the feasibility of plasma sHLA-G as a biomarker for distinguishing patients with HBV infection. sHLA-G levels in AHB (median, 193.1 U/mL; p < 0.001), CHB (median, 324.6 U/mL; p < 0.001), and RHB (median, 14.8 U/mL; p = 0.006) patients was much higher than that in normal controls (median, 9.0 U/mL). A significant difference for sHLA-G levels was also observed between patients with HBV infection (AHB vs CHB, AHB vs RHB, and CHB vs RHB; all p < 0.001). The area under the ROC curve for sHLA-G levels was 1.000 (p < 0.001) for AHB, 0.993 (p < 0.001) for CHB, and 0.604 (p = 0.003) for RHB patients versus normal controls, respectively. Data also indicated that the percentage of CD4(+)CD25(+)FoxP3(+) T regulatory cells and HLA-G(+)CD14(+) monocytes was significantly increased in AHB and CHB patients compared with normal controls (all p < 0.001). Our findings indicated that induction of HLA-G expression may play a role in HBV immune evasion and sHLA-G levels could be a useful biomarker in HBV infection.
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Biomarcadores/sangre , Antígenos HLA-G/sangre , Virus de la Hepatitis B/inmunología , Hepatitis B Crónica/diagnóstico , Hepatitis B Crónica/inmunología , Adulto , Antígenos CD/metabolismo , Recuento de Células , Femenino , Antígenos HLA-G/biosíntesis , Antígenos HLA-G/genética , Virus de la Hepatitis B/patogenicidad , Hepatitis B Crónica/patología , Hepatitis B Crónica/fisiopatología , Humanos , Evasión Inmune , Masculino , Persona de Mediana Edad , Monocitos/metabolismo , Monocitos/patología , Valor Predictivo de las Pruebas , Pronóstico , Curva ROC , Linfocitos T Reguladores/metabolismo , Linfocitos T Reguladores/patología , Regulación hacia Arriba/genética , Regulación hacia Arriba/inmunologíaRESUMEN
Amniotic fluid cells (AFCs) are routinely obtained and expanded in vitro for prenatal diagnosis; nevertheless current knowledge about their properties is limited. The detailed mechanisms underlying normal pregnancies are yet to be discovered. The goal of this study was to identify the immunological aspects of AFCs including cytokine production and human leukocyte antigen (HLA) expression, and to discuss its implication for pregnancy. Eighty-six samples of AFCs were determined for HLA expression before and after culture. Cytokine production was measured with flow cytometry in AFC culture supernatants. Treatment of interferon (IFN)-gamma on induction of HLA-DR expression in cultured AFCs was also investigated. Data indicated that both fresh and cultured AFCs express HLA-I, HLA-G, but not HLA-DR, and the cultured AFCs predominately produce the cytokine interleukin (IL)-6. Importantly, we observed that IFN-gamma could induce HLA-DR expression on cultured AFCs in a dose-dependent manner. Taken together, our results indicated that AFCs are functionally active cells and are significant in pregnancy.
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Líquido Amniótico/citología , Líquido Amniótico/inmunología , Adulto , Células Cultivadas , Citocinas/metabolismo , Femenino , Citometría de Flujo , Antígenos HLA/metabolismo , Antígenos HLA-DR/biosíntesis , Humanos , Interferón gamma/farmacología , EmbarazoRESUMEN
PROBLEM: To investigate possible roles of the natural killer (NK) cell receptor killer immunoglobulin-like receptor (KIR)2DL4 expressed on uterine NK (uNK) cells during pregnancy, we investigated KIR2DL4 expression on uNK cells isolated from patients with early recurrent spontaneous abortion (RSA) and normal early pregnancy women, and functions of KIR2DL4 was analyzed in vitro. METHODS OF THE STUDY: Semi-quantitative RT-PCR analysis was introduced to detect KIR2DL4 messenger RNA (mRNA) expression on uNK cells. Cytotoxicity and cytokine production as the result of interaction of KIR2DL4 and its ligand human leukocyte antigen (HLA)-G were analyzed in vitro with lactic dehydrogenase releasing method and enzyme-linked immunosorbent assay, respectively. RESULTS: No significant difference in KIR2DL4 mRNA expression was observed, while the KIR2DL4 protein level in isolated uNK cells is much higher in normal controls than that in RSA patients. Data showed that HLA-G transfection could not reverse the lysis of uNK against HLA-G transfected K562 cells but induced cytokine production. Furthermore, we demonstrated that, via KIR2DL4, membrane-bound HLA-G could induce high cytotoxicity and cytokine production in a high cytotoxic, IL-2 dependent human NK cell line NK-92 cells. CONCLUSION: Our data suggest that KIR2DL4 might play a crucial implication for human pregnancy.