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TP53 aberrations are found in approximately 10% of patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) and are considered early driver events affecting leukemia stem cells. In this study, we compared features of a total of 84 patients with these disorders seen at a tertiary cancer center. Clinical and cytogenetic characteristics as well as immunophenotypes of immature blast cells were similar between AML and MDS patients. Median overall survival (OS) was 226 days (95% confidence interval [CI], 131-300) for the entire cohort with an estimated 3-year OS rate of 11% (95% CI, 6-22). OS showed a significant difference between MDS (median, 345 days; 95% CI, 235-590) and AML patients (median, 91 days; 95% CI, 64-226) which is likely due to a different co-mutational pattern as revealed by next-generation sequencing. Transformation of TP53 aberrant MDS occurred in 60.5% of cases and substantially reduced their survival probability. Cox regression analysis revealed treatment class and TP53 variant allele frequency as prognostically relevant parameters but not the TP53-specific prognostic scores EAp53 and RFS. These data emphasize similarities between TP53 aberrant AML and MDS and support previous notions that they should be classified and treated as a distinct disorder.
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Leucemia Mieloide Aguda , Síndromes Mielodisplásicos , Citogenética , Humanos , Inmunofenotipificación , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Mutación , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/tratamiento farmacológico , Síndromes Mielodisplásicos/genética , Proteína p53 Supresora de Tumor/genéticaRESUMEN
OBJECTIVES: Vitamin D has potent immunoregulatory features and modulates innate and adaptive immune responses. There is a significant association between intrauterine infection-associated inflammatory responses and pregnancy complications such as abortion and preterm labor. Here, we investigated how 1,25 (OH)2 D3 could modulate inflammatory responses of endometrial cells. DESIGN: This is an in vitro experimental study. Endometrial stromal cells (ESCs) and whole endometrial cells (WECs) were collected from 15 apparently normal women, and the immunomodulatory effects of 1,25 (OH)2 D3 on lipopolysaccharide (LPS)- or lipoteichoic acid (LTA)-treated ESCs and WECs were investigated. Participants/Materials, Setting, and Methods: Women with no history of abortion, infertility, endometriosis, or sign of vaginal infection were enrolled in this study. Endometrial samples were collected by gynecologists using a Pipelle pipette in the proliferative phase of the menstrual cycle. WECs and ESCs were collected and treated with either LPS or LTA. The levels of IL-6, IL-8, and TNF-α in culture supernatants were quantified using the ELISA technique. TLR2, TLR4, and MyD88 expressions were assessed by RT-qPCR. TLR4 expression at the protein level was studied by the Western blot technique. RESULTS: 1,25 Dihydroxycholecalciferol (1,25 (OH)2 D3) significantly reduced TNF-α production in LPS-activated ESCs and TNF-α and IL-6 production by LTA-stimulated WECs. In contrast, 1,25 (OH)2 D3 pretreatment increased the production of IL-8 by LPS- and LTA-stimulated endometrial cells. 1,25 (OH)2 D3 pretreatment markedly reduced LPS-induced TLR4 protein expression by ESCs. LPS treatment of ESCs significantly induced MyD88 gene expression. This effect was reversed when these cells were pretreated with 1,25 (OH)2 D3 before stimulation with LPS. LIMITATIONS: Because of the small size of samples, doing experiments all together on some samples was not feasible. Confirmation of the results obtained here needs well-designed in vivo studies. CONCLUSIONS: 1,25 (OH)2 D3 is an immunomodulatory molecule essential for maintaining endometrial immune homeostasis by controlling potentially harmful inflammatory responses associated with female reproductive tract infections.
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Calcitriol/farmacología , Endometrio/inmunología , Inflamación/prevención & control , Receptor Toll-Like 2/efectos de los fármacos , Receptor Toll-Like 4/efectos de los fármacos , Adulto , Citocinas/biosíntesis , Citocinas/efectos de los fármacos , Femenino , Expresión Génica/efectos de los fármacos , Humanos , Factores Inmunológicos/farmacología , Lipopolisacáridos/farmacología , Factor 88 de Diferenciación Mieloide/efectos de los fármacos , Factor 88 de Diferenciación Mieloide/genética , Embarazo , Células del Estroma/efectos de los fármacos , Células del Estroma/fisiología , Ácidos Teicoicos/farmacología , Receptor Toll-Like 2/fisiología , Receptor Toll-Like 4/fisiologíaRESUMEN
Excessive expression of subunit 1 of GIRK1 in ER+ breast tumors is associated with reduced survival times and increased lymph node metastasis in patients. To investigate possible tumor-initiating properties, benign MCF10A and malign MCF7 mammary epithelial cells were engineered to overexpress GIRK1 neoplasia associated vital parameters and resting potentials were measured and compared to controls. The presence of GIRK1 resulted in resting potentials negative to the controls. Upon GIRK1 overexpression, several cellular pathways were regulated towards pro-tumorigenic action as revealed by comparison of transcriptomes of MCF10AGIRK1 with the control (MCF10AeGFP). According to transcriptome analysis, cellular migration was promoted while wound healing and extracellular matrix interactions were impaired. Vital parameters in MCF7 cells were affected akin the benign MCF10A lines, but to a lesser extent. Thus, GIRK1 regulated cellular pathways in mammary epithelial cells are likely to contribute to the development and progression of breast cancer.
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Neoplasias de la Mama/genética , Carcinogénesis/genética , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/genética , Neoplasias/genética , Neoplasias de la Mama/patología , Movimiento Celular/genética , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Metástasis Linfática , Células MCF-7 , Glándulas Mamarias Humanas/metabolismo , Glándulas Mamarias Humanas/patología , Neoplasias/patología , Transcriptoma/genéticaRESUMEN
Numerous studies showed abnormal expression of ion channels in different cancer types. Amongst these, the potassium channel gene KCNJ3 (encoding for GIRK1 proteins) has been reported to be upregulated in tumors of patients with breast cancer and to correlate with positive lymph node status. We aimed to study KCNJ3 levels in different breast cancer subtypes using gene expression data from the TCGA, to validate our findings using RNA in situ hybridization in a validation cohort (GEO ID GSE17705), and to study the prognostic value of KCNJ3using survival analysis. In a total of > 1000 breast cancer patients of two independent data sets we showed a) that KCNJ3 expression is upregulated in tumor tissue compared to corresponding normal tissue (p < 0.001), b) that KCNJ3 expression is associated with estrogen receptor (ER) positive tumors (p < 0.001), but that KCNJ3 expression is variable within this group, and c) that ER positive patients with high KCNJ3 levels have worse overall (p < 0.05) and disease free survival probabilities (p < 0.01), whereby KCNJ3 is an independent prognostic factor (p <0.05). In conclusion, our data suggest that patients with ER positive breast cancer might be stratified into high risk and low risk groups based on the KCNJ3 levels in the tumor.
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Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/diagnóstico , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/metabolismo , Factores de Edad , Neoplasias de la Mama/mortalidad , Estudios de Cohortes , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Metástasis Linfática , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Receptor ErbB-2/metabolismo , Análisis de Supervivencia , Regulación hacia ArribaRESUMEN
Increased expression levels of KCNJ3 have been correlated with lymph node metastases and poor prognosis in patients with breast cancer, suggesting a prognostic role of KCNJ3 We aimed to establish protocols for the detection of KCNJ3 in formalin-fixed, paraffin-embedded (FFPE) breast cancer tissue. Several antibodies were tested for sensitivity and specificity by western blot, followed by optimisation of the immunohistochemistry (IHC) procedure and establishment of KCNJ3 mRNA in situ hybridisation (ISH). Methods were validated by processing 15 FFPE breast cancer samples for which microarray data were available. Spearman's rank correlation analysis resulted in borderline significant correlation for IHC versus ISH (rS: 0.625; p<0.05) and IHC versus microarray (rS: 0.668; p<0.01), but in significant correlation for ISH versus microarray (rS: 0.861; p<0.001). The ISH method was superior to IHC, regarding robustness, sensitivity and specificity and will aid to further study expression levels of KCNJ3 in both malignant and physiological conditions.
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Biomarcadores de Tumor/genética , Neoplasias de la Mama/diagnóstico , Carcinoma/diagnóstico , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/genética , Adulto , Anciano , Biomarcadores de Tumor/metabolismo , Western Blotting , Mama/patología , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Femenino , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/metabolismo , Células HEK293 , Humanos , Inmunohistoquímica , Hibridación in Situ , Células MCF-7 , Persona de Mediana Edad , Adhesión en Parafina , Pronóstico , ARN Mensajero/análisis , Sensibilidad y EspecificidadRESUMEN
Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2-30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production.
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Apoptosis , Neoplasias de la Mama/patología , Movimiento Celular , Kisspeptinas/metabolismo , Placenta/metabolismo , Receptores de Estrógenos/metabolismo , Adulto , Western Blotting , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Proliferación Celular , Femenino , Humanos , Técnicas para Inmunoenzimas , Inmunoprecipitación , Kisspeptinas/genética , Embarazo , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Estrógenos/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , Cicatrización de Heridas , Adulto JovenRESUMEN
BACKGROUND: Toll-like receptor (TLR)-mediated inflammatory processes are supposed to be involved in pathophysiology of spontaneous abortion and preterm labor. Here, we investigated functional responses of human endometrial stromal cells (ESCs) and whole endometrial cells (WECs) to lipopolysaccharide (LPS) and lipoteichoic acid (LTA). METHODS: Endometrial tissues were obtained from 15 cycling women who underwent laparoscopic tubal ligation. Modulation of TLR2, TLR4 and MyD88 expression and production of pro-inflammatory cytokines by WECs and ESCs in response to LPS and LTA were assessed. RESULTS: WECs and ESCs expressed significant levels of TLR4 and MyD88 transcripts but, unlike WECs, ESCs failed to express TLR2 gene. Regardless of positive results of Western blotting, ESCs did not express TLR4 at their surface as judged by flow cytometry. Immunofluorescent staining revealed intracellular localization of TLR4 with predominant perinuclear pattern. LPS stimulation marginally increased TLR4 gene expression in both cell types, whereas such treatment significantly upregulated MyD88 gene expression after 8 hr (p < 0.05). At the protein level, however, LPS activation significantly increased TLR4 expression by ESCs (p < 0.05). LTA stimulation of WECs was accompanied with non-significant increase of TLR2 and MyD88 transcripts. LPS and LTA stimulation of WECs caused significant production of IL-6 and IL-8 in a dose-dependent manner (p < 0.05). Similarly, ESCs produced significant amounts of IL-6, IL-8 and also TNF-α in response to LPS activation (p < 0.05). CONCLUSION: Our results provided further evidence of initiation of inflammatory processes following endometrial TLR activation by bacterial components which could potentially be harmful to developing fetus.
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Mechanical interaction between cells - specifically distortion of tensional homeostasis-emerged as an important aspect of breast cancer genesis and progression. We investigated the biophysical characteristics of mechanosensitive ion channels (MSCs) in the malignant MCF-7 breast cancer cell line. MSCs turned out to be the most abundant ion channel species and could be activated by negative pressure at the outer side of the cell membrane in a saturable manner. Assessing single channel conductance (GΛ) for different monovalent cations revealed an increase in the succession: Li(+) < Na(+) < K(+) ≈Rb(+) ≈ Cs(+). Divalent cations permeated also with the order: Ca(2+) < Ba(2+). Comparison of biophysical properties enabled us to identify MSCs in MCF-7 as ion channels formed by the Piezo1 protein. Using patch clamp technique no functional MSCs were observed in the benign MCF-10A mammary epithelial cell line. Blocking of MSCs by GsMTx-4 resulted in decreased motility of MCF-7, but not of MCF-10A cells, underscoring a possible role of Piezo1 in invasion and metastatic propagation. The role of Piezo1 in biology and progression of breast cancer is further substantiated by markedly reduced overall survival in patients with increased Piezo1 mRNA levels in the primary tumor.
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Neoplasias de la Mama/metabolismo , Movimiento Celular , Canales Iónicos/metabolismo , Mecanotransducción Celular , Proteínas de Neoplasias/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Femenino , Humanos , Canales Iónicos/genética , Transporte Iónico/genética , Células MCF-7 , Invasividad Neoplásica , Proteínas de Neoplasias/genéticaRESUMEN
Identification of bacterial proteins that contribute to the replication and survival of the engulfed bacteria within phagolysosome is critical in the pathogenesis of intracellular bacteria. Heat shock proteins (HSPs) are molecular chaperones that prevent unwanted protein aggregation and protect the bacteria against cell stress. In order to study the potential of HspA for development of a Brucella subunit vaccine, immunogenicity and protective efficacy of recombinant HspA (rHspA) from Brucella melitensis was evaluated in BALB/c mice. The hspA gene was cloned in pDEST42 and the resulting recombinant protein was used as subunit vaccine. rHspA elicited mixed TH1/TH2 immune responses with higher titers of specific IgG1 than IgG2a. In lymphocyte transformation assay, splenocytes of immunized mice exhibited a strong recall proliferative response with high amounts of IFN-γ, IL-12, IL-10 and IL-6 and very low levels of IL-5 and IL-4 production. The protective effect of rHspA was evaluated by administering rHspA to mice that resulted in a significant reduction in bacterial load and high degree of protection against B. melitensis challenge compared to control mice (p<0.001). These results suggest that rHspA may be a useful candidate for the development of subunit vaccine against brucellosis.
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Proteínas Bacterianas/inmunología , Vacuna contra la Brucelosis/uso terapéutico , Brucella melitensis/inmunología , Brucelosis/prevención & control , Proteínas de Choque Térmico/inmunología , Animales , Proteínas Bacterianas/aislamiento & purificación , Vacuna contra la Brucelosis/inmunología , Proliferación Celular , Femenino , Proteínas de Choque Térmico/aislamiento & purificación , Inmunización/métodos , Linfocitos/fisiología , Ratones , Ratones Endogámicos BALB C , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificaciónRESUMEN
BACKGROUND: Many types of tumors are organized in a hierarchy of heterogeneous cell populations with different molecular signature. Such heterogeneity may be associated with different responsiveness to microenvironment stimuli. In the present study, the effects of lipopolysaccharide (LPS) and lipoteichoic acid (LTA), as well-known mediators of inflammation, on cancerous behavior of three prostate tumor cells, LNCaP, PC3 and DU145, were investigated. METHODS: Expression of TLR1-10, CD14 and MyD88 transcripts was investigated by RT-PCR. Protein expression of TLR2 and 4 was scrutinized by flow cytometry, immunofluorescent staining and Western blotting. Experiments were set up to assess the effects of LPS and LTA at different concentrations and times on cell proliferation, extracellular matrix invasion, adhesion and cytokine production. RESULTS: We showed that prostate cancer cell lines differentially express TLR1-10, MyD88 and CD14 transcripts. DU145 failed to express TLR4 gene. Positively-identified TLR2 protein in all prostate cancer cells and TLR4 protein in PC3 and LNCaP by Western blotting was not accompanied by cell surface expression, as judged by flow cytometry. Immunofluorescent staining clearly demonstrated predominantly perinuclear localization of TLR2 and TLR4. LTA activation of all prostate cancer cells significantly increased cell proliferation. Regardless of lacking TLR4, DU145 cells proliferated in response to LPS treatment. While LPS caused increased invasiveness of LNCaP, invasive capacity of PC3 was significantly reduced after LPS or LTA stimulation. Stimulation of all prostate tumor cells with LTA was associated with increased cell adhesion and IL-8 production. IL-6 production, however, was differentially regulated by LPS stimulation in prostate tumor cells. CONCLUSION: The data shows that cancer cells originated from the same histologically origin exhibit heterogeneous response to the same TLR ligand. Therefore, a thorough and comprehensive judgment on how and to what extent a particular cancer is affected by TLR agonist could not be inferred by studying an individual cell line.
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BACKGROUND: Despite the extensive information available in the literature, cell surface marker signature of human Amniotic Epithelial Cells (hAECs) remains controversial. The aim of the present study was to characterize immunophenotypic features, proliferative capacity and immunogenicity of hAECs. We also tested whether expression of some cell surface markers is influenced by the type of trypsin used for tissue digestion. METHODS: Single cell suspensions of amniotic membranes from four human placentas were isolated by enzymatic digestion and expression of CD9, CD10, CD29, CD34, CD38, CD44, CD45, CD73, CD105, CD133, HLA-I, HLA-DR, HLA-G, SSEA-4, STRO-1 and OCT-4 was then evaluated by flow cytometry. The differential impact of four trypsin types on the yield and expression of CD105 and HLA-I was also determined. The proliferative capacity of cultured hAECs was assessed and compared in the presence and absence of Epidermal Growth Factor (EGF). To test their immunogenicity, hAECs were injected into Balb/c mice and the reactivity of hyperimmunized sera was examined by immunofluorescence staining. RESULTS: Nearly all purified cells expressed mesenchymal markers, CD9, CD10, CD29, and CD73 and the embryonic marker, SSEA-4. A large proportion of the cells also expressed STRO-1 and OCT-4. The purified cells also expressed HLA-G and HLA-I. A very small proportion of hAECs expressed CD34, CD38, CD44, CD133 and HLA-DR. The type of trypsin used for enzymatic digestion affected both the percentage and expression of HLA-I and CD105. hAECs revealed substantial proliferative capacity only when cultured in the medium supplemented with EGF. These cells were shown to be capable of inducing high amounts of anti-donor antibodies. CONCLUSION: Here we provided evidence that hAECs are immunogenic cells with high level of HLA-I expression. Furthermore, this work highlighted the impact of isolation procedure on the immunophenotype of hAEC.
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Approximately, 15-20% of all cancers worldwide are caused by infectious agents. Understanding the role of infectious agents on cancer development might be useful for developing new approaches to its prevention. Mycoplasma genitalium is a clinically important sexually transmitted pathogen that has been associated with several human diseases. There have been a few studies suggestive of probable roles of Mycoplasma genitalium in cancer development, including prostate and ovarian cancers and lymphomas, but the role of this microorganism like other Mycoplasma species in neoplasia is still conjectural. Considering the prevalence of Mycoplasma genitalium infections and also the emergence of resistant strains, Mycoplasma genitalium needs more attention in the infectious agent cancer-causing research area.
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Infecciones por Mycoplasma/complicaciones , Mycoplasma genitalium/patogenicidad , Neoplasias/etiología , HumanosRESUMEN
Lipopolysaccharide (LPS) is an important structural component of the outer cell membrane complex of gram negative microorganisms. Its causative role in gram negative bacteria-induced diseases and broad applications in different kinds of cell stimulation experiments provided a conceptual basis for studies directed at the isolation, purification, and detailed chemical characterization of LPS. The main problem with LPS purification protocols is the contamination of the end product with nucleic acids and proteins in variable proportions which could potentially interfere with downstream applications. In this study, a simple procedure for purification of LPS from Escherichia coli (E.coli) and Salmonella typhi (S.typhi) with high purity and very low contaminating nucleic acids and proteins based on the hot phenol-water extraction protocol has been introduced. The purity of extracted LPS was evaluated by silver and coomassie blue staining of SDS-PAGE gels and HPLC analysis. Limulus Amebocyte Lysate (LAL) coagulation activity and rabbit pyrogen assay were exploited to monitor the functionality of purified LPS. The results showed that DNase and RNase treatment of the sample is essential after the sonication step to eliminate nucleic acid contamination in the LPS fraction. Silver staining demonstrated ladder pattern which is characteristic of LPS. No contaminating protein was found as assessed by coomassie blue staining. HPLC fractionation revealed high degree of purity comparable with commercial LPS. Parenteral administration of purified LPS resulted in substantial increase of rabbits' body temperature (mean: 1.45°C). LAL coagulation assay confirmed the functional activity of the purified LPS. In conclusion, the protocol presented here could be employed for isolation of LPS with high purity and functional activity.
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OBJECTIVE: To investigate the expression and localization of vitamin D(3) receptor (VDR) in reproductive organs of cycling mice. DESIGN: Experimental animal study. SETTING: Academic research center. ANIMAL(S): Mature (8 to 12 weeks old) cycling female Balb/c mice. INTERVENTION(S): Reproductive tissue, including endometrium, ovary, and fallopian tubes, were collected at each phase of estrous cycle to examine VDR expression. MAIN OUTCOME MEASURE(S): Expression of VDR messenger (mRNA) was determined by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). The presence and localization of VDR was assessed by immunohistochemistry, and the intensity of VDR expression was quantified with U.S. National Institutes of Health image-analysis software. RESULT(S): The VDR mRNA was expressed in the endometrium throughout the estrous cycle. The relative expression of VDR mRNA at the estrus phase was more prominent compared with the other phases. Immunohistochemical analysis revealed that dendritic cells, macrophages, and luminal and glandular epithelial cells of the endometrium, granulosa, and cumulus oophorus cells of the ovary and fallopian epithelial cells strongly express VDR, particularly during the estrus phase. CONCLUSION(S): Our findings have demonstrated, for the first time, that VDR is present and differentially expressed in murine reproductive organs throughout the estrous cycle. Further studies are required to evaluate the functional immunologic role of VDR.
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Endometrio/metabolismo , Ciclo Estral , Trompas Uterinas/metabolismo , Receptores de Calcitriol/biosíntesis , Animales , Femenino , Ratones , Ratones Endogámicos BALB C , Ovario/metabolismo , ARN Mensajero/metabolismo , Receptores de Calcitriol/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
To develop an efficient dendritic cell (DC)-based immunotherapy protocol, we examined whether simultaneous pulsing of DCs with a given antigen and a third-party antigen could enhance their antigen presentation capacity. Purified splenic DCs of Balb/c mice were pulsed separately with immunoglobulin G, ovalbumin, conalbumin, P15 peptide of Mycobacterium tuberculosis, and prostate-specific antigen or double combinations of the aforementioned antigens. In some settings, DCs pulsed with 1 antigen were mixed equally with those pulsed with another antigen. Antigen-pulsed DCs were injected into the footpad of syngeneic mice and proliferation of whole, CD4 and CD8 depleted lymph node cells was measured after restimulation with cognate antigen. Antigen-specific production of interferon-gamma (IFNgamma) was tested in culture supernatants. Frequency of responding lymph node cells was determined by IFNgamma enzyme-linked immunosorbent spot assay. Our results showed that copulsing of DCs with 2 unrelated antigens increased the capacity of DCs to induce antigen-specific T-cell proliferation against both antigens up to 16-fold. Injection of 2 populations of DCs each pulsed with a different antigen, increased proliferation of primed T cells significantly as well. Both CD4 and CD8 depleted populations showed vigorous proliferative response in copulsing system. In addition, copulsing of DCs with 2 antigens resulted in higher frequency of antigen-specific responding cells and significantly more IFNgamma production. Our results clearly showed that unrelated peptides and proteins could be used to enhance efficacy of DC-based vaccines and in this system, each antigen served to help the other one, a condition that we termed as "mutual helper effect."