DC-SIGN receptor is expressed by cells from cutaneous leishmaniasis lesions and differentially binds to Leishmania (Viannia) braziliensis and L. (Leishmania) amazonensis promastigotes

BACKGROUND Dendritic cells (DCs) specific intercellular adhesion molecule (ICAM)-3-grabbing non integrin receptor (DC-SIGN) binds to subgenera Leishmania promastigotes mediating its interaction with DC and neutrophils, potentially influencing the infection outcome. OBJECTIVES In this work, we investigated whether DC-SIGN receptor is expressed in cells from cutaneous leishmaniasis (CL) lesions as well as the in vitro binding pattern of Leishmania (Viannia) braziliensis (Lb) and L. (L.) amazonensis (La) promastigotes. METHODS DC-SIGN receptor was labeled by immunohistochemistry in cryopreserved CL tissue fragments. In vitro binding assay with CFSE-labeled Lb or La promastigotes and RAJI-transfecting cells expressing DC-SIGN (DC-SIGNPOS) or mock-transfected (DC-SIGNNEG) were monitored by flow cytometry at 2 h, 24 h and 48 h in co-culture. RESULTS In CL lesion infiltrate, DC-SIGNPOS cells were present in the dermis and near the epidermis. Both Lb and La bind to DC-SIGNPOS cells, while binding to DC-SIGNNEG was low. La showed precocious and higher affinity to DC-SIGNhi population than to DC-SIGNlow, while Lb binding was similar in these populations. CONCLUSION Our results demonstrate that DC-SIGN receptor is present in L. braziliensis CL lesions and interact with Lb promastigotes. Moreover, the differences in the binding pattern to Lb and La suggest DC-SIGN can influence in a difference way the intake of the parasites at the first hours after Leishmania infection. These results raise the hypothesis that DC-SIGN receptor could participate in the immunopathogenesis of American tegumentary leishmaniasis accounting for the differences in the outcome of the Leishmania spp. infection.

Tinker, tailor, soldier, cell: the role of C-type lectins in the defense and promotion of disease

C-type lectins (CTLs) represent a large family of soluble and membrane-bound proteins which bind calcium dependently via carbohydrate recognition domains (CRDs) to glycan residues presented on the surface of a variety of pathogens. The deconvolution of a cell's glycan code by CTLs underpins several important physiological processes in mammals such as pathogen neutralization and opsonization, leukocyte trafficking, and the inflammatory response. However, as our knowledge of CTLs has developed it has become apparent that the role of this innate immune family of proteins can be double-edged, where some pathogens have developed approaches to subvert and exploit CTL interactions to promote infection and sustain the pathological state. Equally, CTL interactions with host glycoproteins can contribute to inflammatory diseases such as arthritis and cancer whereby, in certain contexts, they exacerbate inflammation and drive malignant progression. This review discusses the 'dual agent' roles of some of the major mammalian CTLs in both resolving and promoting infection, inflammation and inflammatory disease and highlights opportunities and emerging approaches for their therapeutic modulation.

Association of CD209 (DC-SIGN) rs735240 SNV with paucibacillary leprosy in the Brazilian population and its functional effects

BACKGROUND Leprosy, caused by Mycobacterium leprae, is a public health problem in Brazil that affects peripheral nerves, resulting in physical disabilities. During host-pathogen interactions, the immune response determines leprosy outcomes from a localised (paucibacillary) form to a disseminated (multibacillary) form. The recognition of M. leprae involves the DC-SIGN receptor, which is present on the dendritic cells (DCs) and participates in immune activation. OBJECTIVES To evaluate the association of polymorphisms in the promoter region of the gene encoding DC-SIGN (CD209) and the clinical form of leprosy, and to investigate its functional effects. METHODS The study population included 406 leprosy patients from an endemic area in Brazil [310 multibacillary (MB); 96 paucibacillary (PB)]. A functional evaluation based on the effects of the single nucleotide variant (SNV) associated with PB leprosy on the specific immune response was also performed. RESULTS The GA genotype and the presence of the A allele of rs735240 (-939G>A) were associated with PB leprosy [OR: 2.09 (1.18-3.69) and 1.84 (1.07-3.14), respectively]. Carriers of the A allele showed reduced expression of CD209 and TGF-β1 in leprosy lesions in comparison with individuals with GG genotype, in addition to a higher response to the Mitsuda test. CONCLUSION These data suggest that rs735240 influences the immune response against M. leprae and clinical presentation of leprosy.

DC-SIGN molecules promote EV71 infection in dendritic cells in vitro / 临床检验杂志

Objective@#To investigate the influence of dendritic cell specific intercellular adhesion molecule-3 grabbing non integrin (DC-SIGN) expression on the infection of enterovirus type 71 (EV71) for dendritic cells (DCs) and 293T cells. @*Methods@#Peripheral blood mononuclear cells (PBMCs) were isolated from human peripheral blood by gradient density centrifugation and induced to DCs. The DC-SIGN gene was amplified by polymerase chain reaction (PCR) for construction of transient expression vector pLB-DC-SIGN which was then transfected into 293T cells using Lipofectamine TM 2000. After 293T cell and 293T-pLB-DC-SIGN was infected with EV71, EV71 mRNA was identified by fluorescence quantitative PCR. EV71/VP1 was identified by western blot. After the expression of DC-SIGN on DCs was blocked by yeast mannan, EV71 mRNA was identified by fluorescence quantitative PCR and EV71/VP1 was identified by western blot. @*Results@#EV71 viral load and EV71/VP1 expression level in 293T cells overexpressed DC-SIGN was significantly higher than that of control 293T, while the viral load and EV71/VP1 expression level in DCs blocked with DC-SIGN inhibitor was lower than that of control DCs (P＜0.05). @*Conclusion@#DC-SIGN may be one of the receptors of EV71 who promote EV71 infection in DCs and 293T cells in vitro.

Mycoplasma pneumoniae capsular polysaccharides inhibit phagocytosis and membrane molecules expression of dendritic cells / 中国免疫学杂志

Objective:To study the influences of Mycoplasma penumoniae capsular polysaccharide (CPS) on the phagocytosis and membrane molecules expression of the human peripheral blood mononuclear cells derived dendritic cells by binding to dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN),so as to know the effect of CPS on the maturation of dendritic cells.Methods:M.pneumoniae strain was cultivated and CPS was extracted.Human peripheral blood mononuclear cells were separated and induced to dendritic cells,then identified the cells by flow cytometry and observation under the microscope.CPS was used to treat dendritic cells or cells pretreated with DC-SIGN monoclonal antibody,and then FITC-dextran phagocytosis and surface markers CD83,HLA-DR,CD80 and CD86 were detected by flow cytometry.Results:The dendritic cells tended to form colony groups.The positive rate of CD11c molecule in the cultured dendritic cells was about 86.27％.After stimulated by CPS,the FITC-dextran fluorescence mean intake by dendritic cells were increased (P＜0.05),while the cell surface membrane molecules CD83,HLA-DR,CD80 and CD86 were decreased significantly when compared with the PBS treated control cells(P＜0.05).When blocked DC-SIGN with the monoclonal antibody,the FITC-dextran fluorescence mean and membrane molecules expression had no statistical difference with the control cells(P＞0.05).Conclusion:M.pneumoniae CPS can promote the phagocytic function of DC and inhibit the expression of CD83,HLA-DR,CD80 and CD86.

In vitro binding ability of transglutaminase 3 to dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin / 中华皮肤科杂志

Objective To evaluate the recognition and uptake of transglutaminase 3 (TG3) by dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) receptors on the membrane surface of DC-SIGN-transfected human embryonic kidney (HEK) 293T cells and monocytederived dendritic cells (MDDCs).Methods The eukaryotic expression vector pGCMV-enhanced green fluorescent protein (EGFP) containing DC-SIGN gene fragments was transfected into HEK293T cells to prepare DC-SIGN-EGFP-HEK293T cells by using liposome transfection method.CD14+ monocytes were isolated from peripheral blood samples by magnetic bead-based negative selection,and then were induced by granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) to prepare MDDCs.Laser confocal microscopy and flow cytometry were performed to evaluate the recognition and uptake of TG3 protein by DC-SIGN receptors on the surface of HEK293T cells and MDDCs.MDDCs treated without Alexa Fluor 647 dye-tagged TG3 served as blank control group,and those treated with Alexa Fluor 647 dye alone served as negative control group.Results After co-culture with TG3 for 3 hours,laser confocal microscopy and flow cytometry both showed that TG3 could be recognized by and uptaken through DC-SIGN receptors into HEK293T cells and MDDCs.Flow cytometry also revealed that the binding of TG3 to MDDCs could be partially blocked by DC-SIGN blocking antibodies.Neither the negative control group nor the blank control group showed the recognition and binding of TG3 to HEK293T cells and MDDCs.Conclusion TG3 can serve as a kind of autoantigen to be recognized and bound by DC-SIGN receptors,followed by uptake by dendritic cells.

Role of DC-SIGN induced signaling pathway in the activation of HIV-1 virus / 中国生化药物杂志

Objective To explore the mechanism of latent human immunodeficiency ciency virus type 1 (HIV-1) infection is unclear, especially in dendritic cells (DC).We hypothesized that DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) binds with HIV-1 may activate HIV-1 provirus.Methods We generated a model by transfecting 293T cells with a DC-SIGN expression plasmid and a HIV-1 5'long terminal repeat (LTR) reporter plasmid, and then stimulated the 293T cells with HIV-1 gp120 protein, wild-type HIV-1 and VSV-G-pNL4.3 pseudotype virus ( without gp120 protein).CEM-Bru cells were transfected with the DC-SIGN expression plasmid and stimulated by HIV-1 gp120 protein.Then HIV-1 replication was detected.The involvement of the ERK, p38 and NF-κB pathways signaling in this response were determined by inhibiting the pathways specifically and detecting the phosphorylation of the signaling kinase.Results The HIV-1 5'LTR was reactivated by HIV-1 gp120 in DC-SIGN-expressing 293T cells.After HIV-1 gp120 protein stimulation of the mold of CEM-Bru cells, the increasing expression of HIV-1 Tat mRNA and HIV-1 p24,which implies early and late HIV-1 provirus replication was reactivated by the HIV-1 gp120/DC-SIGN stimulation.HIV-1 gp120/DC-SIGN stimulation reactivates latent HIV-1 provirus via the NF-κB signal pathway.Conclusion HIV-1 gp120/DC-SIGN stimulation reactivates latent HIV-1 provirus via the NF-κB signal pathway.

Immunohistochemical analysis of dendritic cells in oral leukoplakia tissues / 实用口腔医学杂志

Objective:To investigate the functional status of dendritic cells(DCs)in oral leukoplakia(OLK)tissues.Methods:The expression of DC-specific markers CD1 a,CD209,CD1 23 and CD83 in 20 cases of OLK with abnormal dysplasia,1 0 with simple dys-plasia and 1 0 of normal oral mucosa tissues was examined by immunohistochemistry.Results:CD1 a and CD209 positive DCs were found in all cases.More CD1 a positive Langehans cells(LCs)in lamina propria were found in OLK with abnormal dysplasia than in normal o-ral mucosa and OLK with simple dysplasia(P <0.01 ).A great mount of CD209 positive stromal DCs were recruited in OLK.There was no CD83 positive and CD1 23 positive cell in normal oral mucosa,however,CD83 positive mature DCs and CD1 23 positive plasmacytoid DCs(PDCs)were observed in OLK(P <0.01 ).Conclusion:OLK is characterized by the recruitment of different subsets of DCs,the different DC subsets may play an important role in the development of OLK.

DC-SIGN (CD209) CARBOHYDRATE RECOGNITION DOMAIN DOES NOT POLYMORPHIC IN DENGUE VIRUS INFECTED INDONESIAN

Dengue virus (DENV) infection is a significant burden in Indonesia and other tropical countries. DENV infection have wide spectrum of clinical manifestations i.e. asymptomatic, dengue fever, dengue hemorrhagic fever and dengue shock syndrome. The difference of clinical manifestation may due to the deversity of genetic constitution of the host. The C-type lectin DC-SIGN (CD209) has been identified to be the major dengue receptor on human dendritic cells. There are at least five polymorphisms in exon  5 and 6 of DC-SIGN encoded gene which have been identified and recorded in dbSNP. The aim of this work is to measure the frequency of these polymorphisms among asymptomatic and hospitalized DENV infected patients. We enrolled 23 hospitalized and 73 asymptomatic DENV infected patients. Among those subject we performed PCR amplification and DNA direct seqencing for 23 hospitalized DENV infected patients and 24 asymptomatic DENV infected patients. The result showed that there were no polymorphic nucleotides in CD209 encoded gene found among the patients.

DC-SIGN (CD209) Carbohydrate Recognition Domain Is Not Polymorphic in Dengue Virus-Infected Indonesian Patients

Dengue virus (DENV) infection is a significant burden in Indonesia and other tropical countries. DENV infection has a wide spectrum of clinical manifestations, i.e. asymptomatic, dengue fever, dengue hemorrhagic fever and dengue shock syndrome. The variety of clinical manifestations may be due to the diversity of genetic constitution of the host. The C-type lectin DC-SIGN (CD209) has been identified as the major dengue receptor on human dendritic cells. There are at least five polymorphisms in exon 5 and 6 of the DC-SIGN encoded gene which have been identified and recorded in dbSNP. The aim of this work is to measure the frequency of these polymorphisms among asymptomatic and hospitalized DENV-infected patients. We enrolled 23 hospitalized and 73 asymptomatic DENV-infected patients. Among the subjects, we performed PCR amplification and DNA direct seqencing for 23 hospitalized DENV-infected patients and 24 asymptomatic DENV-infected patients. The result showed that there were no polymorphic nucleotides in the CD209 encoded gene among the patients.

Glycodendritic structures: tools to interact with DC-SIGN

The key role of carbohydrates in many biological events has attracted the interest of the scientific community. This fact has demanded the access to new tools necessary to understand this role and the interaction of carbohydrates with their corresponding receptors, lectins. Glycodendrimers and glycodendritic structures in general, have demonstrated to be very efficient and interesting tools to intervene in those processes where carbohydrates participate. In this review, we discuss the different glycodendritic structures that have been used to interfere with DC-SIGN, a very attractive lectin involved in infection processes and in the regulation of the immune response.

O papel chave dos carboidratos em muitos eventos biológicos tem atraído interesse da comunidade científica. Este fato demonstrou o acesso de novas ferramentas para a compreensão da interação dos carboidratos com seus receptores correspondentes, lectinas. Glicodendrímeros e estruturas glicodendríticas, em geral, mostram-se como ferramentas muito eficientes e interessantes para intervir nos processos em que os carboidratos participam. Nesta revisão, discutimos diferentes estruturas glicodendríticas que têm sido úteis para interferir com DC-SIGN, uma lectina muito atraente envolvida em processos infecciosos e na regulação da resposta imune.

The effects of signaling pathways activating DC-SIGN promoter on the activity of HIV-1 5'LTR / 中华微生物学和免疫学杂志

Objective To explore the effects of signaling pathways inducing activation of DC-SIGN promoter on the activity of HIV-1 5'LTR.Methods The sequences of DC-SIGN promoter and HIV-1 5'LTR were amplified by PCR and then cloned into pGL-3/Basic plasmid to constructluciferase reporter plasmids for DC-SIGN promoter and HIV-1 5'LTR.Differentiated THP-1 cells stimulated by PMA (phorbol myristate acetate) were used as the in vitro model of DCs.The activaties of DC-SIGN promoter and HIV-1 5'LTR induced by IL-4 in differentiated THP-1 cells were studied using luciferase reporter plasmids.The signaling pathways were identified by using specific inhibitors.Results IL-4 induced signaling pathways could increase the activities of HIV-1 5'LTR and DC-SIGN promoter for more than two times in THP-1 cells transfected with luciferase reporter plasmids.However,the activity of HIV-1 5'LTR was weaker than that of DCSIGN promoter.ERK/JAK-STAT/NF-κB signal pathway blockers could inhibit the luciferase activity driven by DC-SIGN promoter,of which ERKI/2 blocker showed the strongest inhibitory effect that almost completely blocked IL-4 induction.NF-κB blocker had a significant inhibitory effect on HIV-1 5'LTR activity at a rate of 52.32％,followed by the ERK blocker at a rate of 43.31％.Conclusion This study suggested that IL-4-induced signaling pathways mediate the activation of DC-SIGN promoter and HIV-1 5'LTR through NFκB and ERK.

Molecular half-full mechanisms by phagocityc cells on invasive Aspergilosis / Mecanismos moleculares mediados por celulas fagociticas en la aspergilosis invasiva

Fungus from the Aspergillus genus mainly affects lung tissue, occurring when the integrity of the host immunesystem is compromised. The human body uses immunocompetence conditions from mechanical and enzymatic defenses and the action of the innate immune system cells and also uses adaptive responses to control infection. Neutrophils, macrophages, and dendritic cells are critical as antifungal effector cells possess surface receptors that recognize fungal structures and trigger specific responses. TLRs and Dectin-1 the most studied for this interaction. TLRs are responsible for the production and release of cytokines and Dectin-1 is essential in the phagocytosis of theparticle recognition and production of ROS. The best-studied cytokines and its crucial role in the response toAspergillus spp. are TNF-á, IFN-ã, and IL-12. In this work, we reviewed the main mechanisms related to molecularreceptors on phagocytic cells involved in the recognition of Aspergillus spp. Understanding the immune response insituations of immunocompetence and its comparison in immunodeficient organisms could provide alternatives tocontrol invasive aspergillosis.

IL-4 induced signal pathways regulating DC-SIGN expression in THP-1 cells / 中华微生物学和免疫学杂志

Objective To detect the signal pathways through which IL-4 regulates expression of DC-SIGN in THP-1 cells.Methods We used phorbol 12-myristate 13-acetate(PMA) differentiated THP-1 cells as the in vitro model of monocyte/macrophage cells to study the signal pathways involved in IL-4 regulated expression of DC-SIGN.DC-SIGN mRNA expression was detected by RT-PCR.Cytoplasmic DC-SIGN protein was tested by Western blot.Flow cytometry was used to detect cell surface expression of DC-SIGN.Cytoplasm and nuclear protein of PMA stimulated THP-1 cells induced by IL-4 for 0,10,20,30,60 and 120 min was extracted and detected by Western blot for signal pathway signaling protein and phosphoprotein.Results We found that a high expression of DC-SIGN could be induced by IL-4 at the levels of mRNA and cell surface protein.Up-regulated expression of DC-SIGN was almost completely blocked by the specific inhibitor of ERK pathway,and partly reduced by the specific inhibitors of JAK-STAT and NF-κB pathways.The activation of the three signaling pathways was directly confirmed by testing the phosphorylation of protein kinase within the cytoplasm and nucleus over time.Conclusion Multiple signaling pathways are involved in IL-4 induced high expression of DC-SIGN on THP-1 cells,in which ERK pathway is the main signal pathway.

Mutation analysis of DC-SIGN promoter in chronic hepatitis B patients / 中南大学学报(医学版)

To investigate whether there is mutation in DC-SIGN promoter region in patients with chronic hepatitis B (CHB) and healthy persons previously infected with hepatitis B virus (HBV) and to explore the relationship between the mutation in dendritic cell-specific intercellular adhension molecule-3-grabbing nonintegrin (DC-SIGN) promoter region and HBV.Methods The studied population was composed of two cohorts:47 CHB patients and 20 healthy persons previously infected with HBV.The mutation in DC-SIGN promoter region was detected with PCR,single-stranded conformational polymorphism and heteroduplex analysis,cloning,sequencing and aligning the published DC-SIGN promoter sequence.Results The characteristic mutation within DCSIGN promoter region in HBV infected individuals was observed.In the DC-SIGN promoter region,4 hot spot mutations located in positions - 139,- 142,- 222,and - 336 were observed in the CHB patients,but only 1 spot mutation located in position - 139 was observed in the healthy persons previously infected with HBV.The -336C which was absent in the healthy persons previously infected with HBV was shown in 11 CHB patients (23.40％).The - 139T was far more frequent in the healthy persons previously infected with HBV ( 100％ ) than in the CHB patients (34.04％).Conclusion In the DC-SIGN promoter region,-336C may be a genetic risk factor for developing CHB,but -139T may be associated with protection against HBV.

Role of DC-SIGN in renal tubulointerstitial lesions of immune-mediated experimental nephritis and intervention regulation by anti-P-selectin domain monoclonal antibody / 中华肾脏病杂志

Objective To explore the role of dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) in the tubulointerstitial lesions of immune-mediated nephrotoxic nephritis (NTN) and the intervention regulation by anti-P-selectin lectin-EGF domain monoclonal antibody (PsL-EGFmAb). Methods WKY rats were randomly divided into control,NTN and PsL-EGFmAb-treated groups. The mrs in NTN group were injected with 1 ml nephrotoxic rabbit serum per kilogram of rat body weight; the ones in PsL-EGFmAb-treated group were injected with 2 mg PsL-EGFmAb per kilogram of rat body weight simultaneously and 2 h later after nephrotoxic rabbit serum injection; and those in control group were injected with equal volume of 0.9% saline. Renal function and pathology were observed at day 4, 7 and 14 after the induction of NTN. Distribution of DC-SIGN + dendritic cells (DCs) in renal tissues was measured by immunofluorescence. Real-time PCR was performed to examine the expression of P-selectin,RANTES, TNF-α, IL-10, IFN-γ and IL-4. Expression of MHC Ⅱ , CD80 and DC-SIGN on dendritic cells was analyzed by flow cytometry. Transendothelial migration was used to detect the ability of DCs migration. DCs ability to activate T cells was determined by mixed lymphocyte reaction (MLR). ELISA was used to detect the concentration of IFN-γ and IL-4 in the supernatant of MLR. Results At day 4, immature DC-SIGN+ DCs infiltrated the rat renal tubulointerstium of NTN group, matured at day 14, and enhanced the ability to migrate and activate T cells. The distribution of DC-SIGN + DCs was significantly related to the form of crescent, tubulointerstial lesions and renal function. In addition, expression of chemokine RANTES and proinflammatory cytokine TNF-α continuously augmented since day 4, while anti-inflammatory eytokine IL-10 decreased after markedly increased at day 4. At day 14, IFN-γ/IL-4 mRNA increased, which was obviously related to DCs maturation. The intervention of PsL-EGFmAb supressed the expression of DC-SIGN and CD80 on DCs, depressed DCs maturation, migration and ability to activate T cells,down-regulated proinflammatory cytokines and up-regulated anti-inflammatory cytokines in kidney,and thus regulated Th1/Th2 bias. At the same time, kidneys showed the decrease of crescents,improvement of tnbulointerstium damage and renal function. Conclusions DC-SIGN may mediate DCs tubulointerstitial infiltration. It may be also a potent regulator of local immune reaction imbalance and pathology of tubulointerstium. PsL-EGFmAb may depress DCs migration and downregulate DCs maturation and function through DC-SIGN, and thus having a role in prevention and treatment.

Research on the association of DC-SIGN gene promoter polymorphisms with tuberculosis / 中华微生物学和免疫学杂志

Objective To study the relationship of two variants( -871A/G and -336A/G) polymorphisms of the DC-SIGN gene with the susceptibility to pulmonary tuberculosis in Chinese population.Methods Two hundred and thirty-seven tuberculosis cases and 244 controls were genotyped by pyrosequencing in this case-control study. The analysis of the relationship of the -871A/G and -336A/G polymorphisms with their susceptibility of pulmonary tuberculosis(PTB) and the relationship of the two variants with their clinical correlation of tuberculosis was performed by chi-square test. Results The genotypic frequencies of A/G + G/G and A/A of - 871, 37.6%, 62.4% respectively in cases, and 43.4%, 56. 6%respectively in controls, had no significant difference in statistics. And the genotypic frequencies of A/G + G/G and A/A of -336, 12. 2% ,87.8% respectively in cases, and 14.3% ,85.7% respectively in controls, had also no statistical difference between two groups. Interestingly, a significant association is disclosed between the promoter variant - 336G allele and fever in patients ( P = 0. 037, OR = 0. 191, 95 % CI:0. 040-0. 907 ). Conclusion The single nucleotide polymorphism of -871A/G and -336A/G in DCSIGN gene promoter might not be associated with the susceptibility to tuberculosis in Chinese. Tuberculosis patients with -336G allele are significantly protected fever.

Factores virales y celulares que afectan la transmisión vertical del HIV-1 / Viral and cellular factors affecting vertical transmission of HIV-1

Distintos factores virales y celulares pueden condicionar la susceptibilidad a la infección por el HIV-1. La inmunidad innata constituye la primera línea de defensa contra el virus jugando un papel fundamental en la etapa temprana de la transmisión del HIV-1 previo al desarrollo del sistema inmune adaptativo. Está constituida por elementos celulares como las células NK, granulocitos, macrófagos, células dendríticas, etc. y solubles como quimioquinas, defensinas y proteínas de unión a azúcares (lectinas) capaces de ejercer actividad antiviral. Se ha demostrado que variaciones genéticas de componentes de la respuesta inmune pueden modificar el riesgo de transmisión del HIV-1 y desarrollo de sida. Entre ellos se encuentran primordialmente los co-receptores del virus CCR5 y CXCR4, y las proteínas del complejo mayor de histocompatibilidad clase I y II. Además, características biológicas y evolutivas del HIV-1 pueden modificar el riesgo de la transmisión viral.

Viral and cellular factors may condition susceptibility to HIV-1 infection. Innate immunity represents the fist line of defense against the virus with mayor relevance at initial stages of HIV-1 transmission prior to the development of the adaptative immune system. Cellular components, such as, NK cells, granulocytes, macrophages, dendritic cells, etc and soluble factors like chemokines, defensins and sugar binding proteins (lectins) have antiviral activity. Genetic variations of immune response components can modify the risk of HIV-1 transmission and AIDS development. These mainly include viral co-receptors CCR5 and CXCR4 and HLA class I and II. Furthermore, biologic and evolutionary characteristics of HIV-1 can modify the risk of viral transmission.

Construction of Iuciferase reporter vectors harboring DC-SIGN promoters without AP-1 or ETS-1 transcription factor binding site and detection of their activity / 中华微生物学和免疫学杂志

Objective To detect the role of AP-1 or ETS-1 transcription factor binding sites (TFBS) in activity of DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) pro-moter. Methods Genomic DNA was extracted from peripheral blood. Complete DC-SIGN promoter and those without AP-1 or ETS-1 TFBS were amplified by PCR using designed primers. The PCR products were digested with MLu Ⅰ and Bgl Ⅱ and then ligated into MLu Ⅰ and Bgl Ⅱ digested pGL-3/Basic and pGL-3/En-hancer vectors. Transfection in Hacat and 293 cells was accomplished with Trans Fast liposome. Activity of luciferase was detected after 48 h. Results The DC-SIGN promoters without AP-1 or ETS-1 TFBS and the recombined pGL-3 vectors were correctly constructed. The activity of DC-SIGN promoters without AP-1 was reduced 20% (293) and 10% (Hacat), which was 40%-50% with enhancer. The activity of DC-SIGN pro-moters without ETS-1 was nearly vanished, no matter with or without enhancer. Conclusion ETS-1 TFBS, not AP-1 TFBS, plays an important role in activity of DC-SIGN promoter.

NF-κBp50 is Associated With DC-SIGN Expression Induced by IL-4 in THP-1 Cells / 生物化学与生物物理进展

DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) is specific receptor on Dendritic cells, and plays a pivotal role on antigens presentation. Uptodate, the clear regulation mechanisms for DC-SIGN expression are not available.IL-4 is one of the most important cytokines inducing DC-SIGN production, while, NF-κB is an important transcription factor controlling signaling transduction. Both IL-4 and NF-κB are closely related to DC-SIGN regulation. NF-κB and IL-4 actions on DC-SIGN promoter activity, DC-SIGN expression as well as interactions between IL-4 and NF-κB were investigated in THP-1 cell. It was found that the mutation of NF-κB binding site in DC-SIGN promoter results in DC-SIGN promoter activity decrease about 50%.NF-κBp50 stimulates DC-SIGN expression in THP-1 cells. IL-4 upregulates DC-SIGN expression on THP-1 cells as well as NF-κB production. These data reveal that NF-κB is associated with IL-4 induced DC-SIGN expression.