• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Recognition of a multiple antigen peptide containing sequence from mimotope of the dengue type 3 virus NS4B protein by human antibodies

    2016-11-29 12:06:03NevisAminMaritzaPupoAliciaAguilarSusanazquezYamiraCaballeroRolandoOchoaMarGuzmArmandoAcosta

    Nevis Amin, Maritza Pupo, Alicia Aguilar, Susana Vázquez, Yamira Caballero, Rolando Ochoa, María G Guzmán, Armando Acosta

    1Implementation and Design of Clinical trials, Clinical Research and Impact Evaluation Direction, Finlay Institute, 11600 Havana, Cuba

    2‘Pedro Kourí’ Tropical Medicine Institute (IPK), PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, 17100 Havana, Cuba

    Recognition of a multiple antigen peptide containing sequence from mimotope of the dengue type 3 virus NS4B protein by human antibodies

    Nevis Amin1*, Maritza Pupo2, Alicia Aguilar1, Susana Vázquez2, Yamira Caballero2, Rolando Ochoa1, María G Guzmán2, Armando Acosta1

    1Implementation and Design of Clinical trials, Clinical Research and Impact Evaluation Direction, Finlay Institute, 11600 Havana, Cuba

    2‘Pedro Kourí’ Tropical Medicine Institute (IPK), PAHO/WHO Collaborating Center for the Study of Dengue and its Vector, 17100 Havana, Cuba

    ARTICLE INFO

    Article history:

    Received 15 November 2015

    Received in revised form 20 December 2015

    Accepted 15 January 2016

    Available online 20 February 2016

    MAP

    Antibodies

    NS4B

    Dengue virus

    Objective: To evaluate the recognition of NS4B mimotope, as multiple antigen peptide (MAP), by dengue antibodies presents in serum samples from patients with different serotype infections. Methods: A MAP containing mimotope sequence was synthesized and used to evaluate the recognition of NS4B mimotope as MAP by a panel of 66 human sera from dengue cases by an indirect ELISA assay. Results: The MAP differentiated between sera from dengue viruses infected patients and sera from healthy individuals and the best reactivity was shown by serum from dengue type 3 virus patients. The recognition was more intense with serum from patients with secondary infection. Conclusions: The findings suggest the potential use of NS4B mimotope on the development of a multi-epitope diagnostic tool. These results are important for further immunogenicity studies.

    1. Introduction

    Dengue viruses (DENV) belong to the family Flaviviridae, and the genome encodes 3 structural proteins: the capsid (C), precursor membrane (prM), envelope (E) and 7 non-structural proteins (NS1-NS5). Robust antibody responses are generated to 3 proteins: E, which contains 3 distinct domains, Ⅰ, Ⅱ, and Ⅲ (potent neutralizing activity); prM, which augments infectivity of poorly infectious immature virions; and NS1, which directs complementmediated lysis of infected cells[1]. Serological studies in humans have suggested, that after a DENV infection, people develop serum antibodies against some of the non-structural proteins (NS1, NS3, NS5)[2]. However, few studies have been carried out to characterize the immune response to others non-structural proteins[3].

    The advent of the phage-displayed peptide technology, in which large, complex libraries of filamentous bacteriophage bearing random peptide sequences on their coat proteins can be generated and screened with antibodies, has provided a new approach to identify previously unknown antigens and/or new epitopes on already known antigens[4]. In this approach, phage-displayed peptide libraries are screened with sera from patients who have suffered a particular disease or pathological condition to discover peptide epitopes that are specifically recognized by patient’s sera[5-7].

    The present study extends previous results obtained with the mimotope of the non-structural NS4B DENV protein. The NS4 protein is composed of two distinct domains: NS4A and NS4B which may play a role in viral replication[8], however, the role in humoral immunity of NS4B has been poorly studied. Nevertheless, detection of antibody specific to purified recombinant GST-NS4B antigen was reported in serum samples from dengue patients[9]. Here we evaluate the recognition of NS4B mimotope as MAP by dengue antibodies in serum samples from patients with different dengue serotype infections.

    2. Materials and methods

    2.1. Serum samples

    All the serum specimens used in the study came from a human sera collection stored at -20 ℃. To obtain these sera, all procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008 [Cuadernos de Bioética (Bs As) 2010;15/16:289-348].

    Sera collected from 66 dengue confirmed adult patients and stored at the Dengue Sera Bank of the Virology Department at the ‘Pedro Kouri’ Tropical Medicine Institute of Havana in Cuba were analyzed in this study. Dengue diagnostics was confirmed by virus isolation and identification, RT-PCR and IgM-IgG determination. Cases were classified in primary or secondary infection according to anti-dengue IgG level[10,11]. Serum samples were collected five to seven days or two months after the onset of fever. Sera from healthy donors were obtained from the Cuban National Blood Bank and used as a negative control.

    2.2. Synthetic peptides

    Peptides consisting of the mimotope from NS4B DENV protein, mimotope from E DENV protein (as positive control of antigen)[12] and mimotopes from Hepatitis A virus (HAV) (as negative control of antigen)[13] were synthesized at the Synthetic Peptide Laboratory at the Center for Genetic Engineering and Biotechnology (Havana City) (Table 1). The peptides were named NS4B MAP, E peptide and MAP 46-56, respectively.

    Table 1Sequence of mimotopes contained in synthetic antigens.

    2.3. Indirect ELISA-NS4 MAP and controls

    Multi-well plates (Nunc Maxisorp F8, Life Technologies Limited, Paisley, UK) were coated with 100 μL/well of NS4B MAP: 5 μg/ mL, E peptide: 20 μg/mL or MAP 46-56: 5 μg/mL diluted in 0.05 M sodium carbonate buffer pH 9.6 (coating buffer), and incubated overnight at 4 ℃. Plates were washed 3 times with phosphate buffered saline in 0.05% Tween 20 (PBS/T) and blocked with skimmed milk (3% w/v) in PBS/T (blocking solution) for 1 h at 37 ℃. Human serum samples diluted in blocking solution (1:20, 100 μL/well) were added to the plates and incubated 1 h at 37 ℃. After repeating the washes, bound antibodies were detected with HRP-conjugated anti-human IgG antibodies (Sigma-Aldrich, UK), H2O2and o-phenylenediamine dihydrochloride (Sigma). The reaction was stopped with 0.1 M H2SO4. The absorbance at 492 nm was measured by an automated ELISA reader. All samples were run in duplicate and results were expressed as mean values of optical density (OD) ratios.

    Control ELISAs were run in parallel, in which the E peptide and HAV MAP were used. Each ELISA was performed twice.

    Positivity criteria: The formula ratio=P/N where P is the OD obtained in the sample and N is the OD mean values obtained with sera of healthy donors for the screening of the serum sample with NS4B peptide was employed. A sample with a ratio≥2 was considered positive.

    2.4. Statistical analysis

    The GraphPad Prism statistical software (San Diego, CA, USA) was used. The Mann Whitney test was used to compare the results of OD ratios obtained in each serotype and values of P<0.05 were considered significant.

    3. Results

    To analyse the potential of NS4B mimotope as MAP to behave as antigen, their ability to detect anti-DENV antibodies was assessed. ELISA screening was performed with human sera collected from dengue patients with NS4B MAP. The reactivity of 30 serum samples from secondary cases to DENV-1 (n=10), DENV-3 (n=10) and DENV-4 (n=10) is shown in Figure 1. Serum samples of DENV-2 infection were not available for the study. The OD ratio values for DENV-3 were statistically significant when compared with DENV-1 (P=0.03) and DENV-4 (P=0.04).

    Dengue antibodies from the studied samples were not detected with MAP 46-56 used as control, demonstrating a specific recognition of NS4B MAP by antibodies produced in response to the natural dengue infection. Figure 1 shows the results obtained with dengue 3 sera against MAP 46-56.

    Figure 1. ELISA reactivity of human sera to NS4B mimotope as MAP.

    The unpaired sera of 48 patients from DENV-3 positive cases (20 serum samples collected between five to seven days, and 28 collected after two months of fever onset) were used to compare the response to NS4B antibodies by ELISA-NS4B MAP (Figure 2). These patients were classified in primary or secondary type of infection. NS4B MAP was recognized strongly by samples collected at five to seven days in secondary infection (70%) and only 2 were positive in primary cases. Sera collected≥two months showed the highest percentage of recognition in both primary (93%) and secondary cases (100%); however, the OD ratios were lowest in relation with secondary cases (samples five to seven days). A greater reactivity to E peptide, used as positive control, was observed in sera collected at the convalescent phase of illness (data not shown).

    Figure 2. Recognition of NS4B MAP of serum samples from patients with primary (P 5-7=10 and P≥2 m=13) or secondary (S 5-7=10 and S≥2 m=15) dengue 3 infections by an Indirect ELISA.

    4. Discussion

    One of the advantages of the phage display technology is to reduce complex protein antigens to small structured peptides that retain immune recognition. Mimotopes can potentially serve as lead compounds to develop low molecular weight substitutes of the template protein for the development of diagnostic assays[6,14]. This approach has been widely used in epitope mapping of flavivirus[15-18]. Recently, a mimotope of NS4B protein of DENV-3 was obtained by screening a solid-phase 9mer random peptide library using human immune sera. The selected sequences mimic the binding properties of natural antigen epitopes[19].

    In this study, we detected antibodies against DENV from serum samples of dengue patients using the NS4B mimotope by indirect ELISA. The mimotope was synthesized in the MAP form, because the binding efficiency of an MAP is greater than that of a singlechain peptide. Short synthetic peptides are usually ineffective antigens for solid phase immunoassays owing to their poor ability to attach to solid surfaces. The multimeric nature of MAP constructs have been found to overcome these deficiencies and provide consistently reproducible results in increased surface-binding properties and sensitivity of detection[20]. The high reactivity with DENV-3 can be explained by the fact that the NS4B mimotope was selected with an anti-dengue 3 sera[19]. These data correlate well with the results reported by several authors who identified serotype specific epitopes using the phage-displayed peptide library screening method[15-18,21].

    The serum antibody responses are different following primary and secondary DENV infections. In secondary infections, the stimulation of B-cell memory leads to a rapid rise in DENV-specific IgG that is measurable even on the first day of symptoms. Moreover DENV specific serum IgG titers are much higher in secondary compared to primary infections[1]. Valdes et al[22] have demonstrated that the antibody response to NS5 and NS3 proteins in acute-phase samples from secondary cases is greater than in primary cases, including the intensity of the reaction, due to the high levels of IgG antibodies in secondary cases. The present study confirms these results, with the presence of anti-NS4B antibodies in acute-phase samples from secondary cases, using NS4B mimotope as MAP. Previously, NS4B MAP was shown to induce robust humoral response in mice and these antibodies were able to recognize NS4B protein, which is produced in the first step of viral replication[12]. On the other hand,‘in silico’ analysis predicted potential B-cell epitopes on the NS4B protein including the epitope mimic of NS4B[23]. These preliminary data support the usefulness of NS4B MAP to detect antibodies to DENV in human sera suggesting that the NS4B protein of dengue virus could be implicated in the humoral response. Our findings suggest the potential use of NS4B mimotope for the development of a multi-epitope diagnostic tool. These results are important for further immunogenicity studies towards the evaluation of the mimotope as experimental vaccine.

    Conflict of interest statement

    We declare that we have no conflict of interest.

    Acknowledgments

    The authors would like to thank Dr. Marta Romano for the critical reading of the manuscript.

    [1] Wahala WM, Silva AM. The human antibody response to dengue virusinfection. Viruses 2011; 3(12): 2374-2395.

    [2] Mathew A, West K, Kalayanarooj S, Gibbons RV, Srikiatkhachorn A, Green S, et al. B-cell responses during primary and secondary dengue virus infections in humans. J Infect Dis 2011; 204(10): 1514-1522.

    [3] Anandarao R, Swaminathan S, Khanna N. The identification of immunodominant linear epitopes of dengue type 2 virus capsid and NS4a proteins using pin-bound peptides. Virus Res 2005; 112(1-2): 60-68.

    [4] Paramasivam SK. Diagnostic and immunoprophylactic applications of synthetic peptides in veterinary microbiology. Microbiol Res 2010; 1(1). Doi: 10.4081/mr.2010.e1.

    [5] Gazarian KG, Palacios-Rodriguez Y, Gazarian TG, Huerta L. HIV-1 V3 loop crown epitope-focused mimotope selection by patient serum from random phage display libraries: implications for the epitope structural features. Mol Immunol 2013; 54(2): 148-156.

    [6] Casey JL, Coley AM, Parisi K, Foley M. Peptide mimics selected from immune sera using phage display technology can replace native antigens in the diagnosis of Epstein-Barr virus infection. Protein Eng Des Sel 2009; 22(2): 85-91.

    [7] Houimel M, Dellagi K. Peptide mimotopes of rabies virus glycoprotein with immunogenic activity. Vaccine 2009; 27(34): 4648-4655.

    [8] Miller S, Bartenschlager R. Subcellular localization and membrane topology of the dengue virus type 2 non-structural protein 4B. J Biol Chem 2006; 281: 8854-8863.

    [9] Lázaro L, Mellado G, García J, Escobar A, Santos L, Gutiérrez B, et al. Analysis of antibody responses in human dengue patients from the Mexican coast using recombinant antigens. Vector Borne Zoonotic Dis 2008; 8(1): 69-79.

    [10] Vazquez S, Cabezas S, Perez AB, Pupo M, Ruiz D, Calzada N, et al. Kinetics of antibodies in sera, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infections. Int J Infect Dis 2007; 11(3): 256-262.

    [11] Vazquez S, Acosta N, Ruiz D, Calzada N, Alvarez M, Guzman MG. Immunoglobulin G antibody response in children and adults with acute dengue 3 infection. J Virol Methods 2009; 159(1): 6-9.

    [12] Amin N, Pupo M, Aguilar A, Camacho F, Alvarez M, Caballero Y, et al. Immunogenicity of NS4b dengue 3 virus mimotope presented to the immune system as multiple antigen peptide system. ISRN Virol 2013; 2013(1). Doi: 10.5402/2013/924057.

    [13] Aguilar A, Camacho F, Martínez R, Huerta V, Garay H, Amin N, et al. Study of peptide mimetics of hepatitis a virus conjugated to keyhole limpet hemocyanin and as multiple antigen peptide system. Int J Pept Res Ther 2014; 20(1): 33-42.

    [14] Casey JL, Coley AM, Street G, Parisi K, Devine PL, Foley M. Peptide mimotopes selected from a random peptide library for diagnosis of Epstein-Barr virus infection. J Clin Microbiol 2006; 44(3): 764-771.

    [15] Jiang L, Zhou JM, Yin Y, Fang DY, Tang YX, Jiang LF. Selection and identification of B-cell epitope on NS1 protein of dengue virus type 2. Virus Res 2010; 150(1-2): 49-55.

    [16] Chen YC, Huang HN, Lin CT, Chen YF, King CC, Wu HC. Generation and characterization of monoclonal antibodies against dengue virus type 1 for epitope mapping and serological detection by epitope-based peptide antigens. Clin Vaccine Immunol 2007; 14(4): 404-411.

    [17] Wu HC, Huang YL, Chao TT, Jan JT, Huang JL, Chiang HY, et al. Identification of B-cell epitope of dengue virus type 1 and its application in diagnosis of patients. J Clin Microbiol 2001; 39(3): 977-982.

    [18] Yao ZJ, Kao MC, Loh KC, Chung MC. A serotype-specific epitope of dengue virus 1 identified by phage displayed random peptide library. FEMS Microbiol Lett 1995; 127(1-2): 93-98.

    [19] Amin N, Aguilar A, Chamacho F, Vazquez Y, Pupo M, Ramirez JC, et al. Identification of dengue-specific B-cell epitopes by phage-display random peptide library. Malays J Med Sci 2009; 16(4): 4-14.

    [20] Tam JP, Zavala F. Multiple antigen peptide. A novel approach to increase detection sensitivity of synthetic peptides in solid-phase immunoassays. J Immunol Methods 1989; 124(1): 53-61.

    [21] Tian Y, Chen W, Yang Y, Xu X, Zhang J, Wang J, et al. Identification of B cell epitopes of dengue virus 2 NS3 protein by monoclonal antibody. Appl Microbiol Biotechnol 2013; 97(4): 1553-1560.

    [22] Valdes K, Alvarez M, Pupo M, Vazquez S, Rodriguez R, Guzman MG. Human dengue antibodies against structural and nonstructural proteins. Clin Diagn Lab Immunol 2000; 7(5): 856-857.

    [23] Amin N, Reyes F, Calero R, Camacho F, Acosta A. T and B epitope prediction of NS4B protein of dengue virus type 3. Vaccimonitor 2013; 22(3): 14-21.

    ent heading

    10.1016/j.apjtm.2016.01.019

    *Corresponding author: Nevis Amin, Implementation and Design of Clinical trials, Clinical Research and Impact Evaluation Direction, Finlay Institute. Ave 27, No 19805, La Lisa, AP 16017, 11600 Havana, Cuba.

    Tel: 53 7 2080984

    Fax: 53 7 2086075

    E-mail: namin@finlay.edu.cu

    人妻少妇偷人精品九色| 亚洲综合色惰| 97超碰精品成人国产| 中文字幕人妻熟人妻熟丝袜美| 久久精品久久精品一区二区三区| 大话2 男鬼变身卡| 在线观看一区二区三区激情| 日本黄色片子视频| 大片免费播放器 马上看| 日韩不卡一区二区三区视频在线| 欧美性猛交╳xxx乱大交人| 久久韩国三级中文字幕| 超碰97精品在线观看| 亚洲人成网站高清观看| 日韩国内少妇激情av| 亚洲性久久影院| 国产又色又爽无遮挡免| 又爽又黄无遮挡网站| 久久久久久伊人网av| 天天一区二区日本电影三级| av在线老鸭窝| 九九爱精品视频在线观看| 国产又色又爽无遮挡免| 欧美日韩一区二区视频在线观看视频在线 | 一区二区三区乱码不卡18| 日本wwww免费看| 寂寞人妻少妇视频99o| 特级一级黄色大片| 久久精品国产a三级三级三级| 亚洲久久久久久中文字幕| av在线老鸭窝| 久久久欧美国产精品| 香蕉精品网在线| 国产精品不卡视频一区二区| 性色avwww在线观看| 国产免费视频播放在线视频| 国产精品人妻久久久久久| 老师上课跳d突然被开到最大视频| 综合色av麻豆| 亚洲成色77777| 欧美97在线视频| 久久精品国产鲁丝片午夜精品| 国产一级毛片在线| 日韩一区二区三区影片| 国产成人精品一,二区| 欧美最新免费一区二区三区| 久久精品久久久久久噜噜老黄| 免费大片18禁| 18禁动态无遮挡网站| 中国美白少妇内射xxxbb| 亚洲国产高清在线一区二区三| 国产高潮美女av| 久久久亚洲精品成人影院| 午夜免费观看性视频| 性色av一级| 久久国内精品自在自线图片| 国产视频首页在线观看| 一级二级三级毛片免费看| 一级黄片播放器| 秋霞伦理黄片| 三级经典国产精品| 我的老师免费观看完整版| 亚洲精品自拍成人| 国产伦理片在线播放av一区| 精品亚洲乱码少妇综合久久| 亚洲av成人精品一区久久| 成人亚洲欧美一区二区av| 2021天堂中文幕一二区在线观| 视频区图区小说| 黄片wwwwww| 日本熟妇午夜| 国产成人精品一,二区| 又爽又黄无遮挡网站| 免费观看的影片在线观看| 国产精品熟女久久久久浪| 国产在线一区二区三区精| 色综合色国产| 亚洲综合色惰| 嫩草影院新地址| 久久久久精品性色| 丝袜美腿在线中文| 寂寞人妻少妇视频99o| 国产成人午夜福利电影在线观看| 内地一区二区视频在线| 国产乱来视频区| 嘟嘟电影网在线观看| 国产欧美日韩精品一区二区| 日韩av在线免费看完整版不卡| 麻豆国产97在线/欧美| 亚洲国产精品成人久久小说| 免费看不卡的av| 欧美精品人与动牲交sv欧美| 又大又黄又爽视频免费| 日本wwww免费看| 高清日韩中文字幕在线| 3wmmmm亚洲av在线观看| 亚洲一区二区三区欧美精品 | 日韩国内少妇激情av| 日韩国内少妇激情av| 国产精品99久久久久久久久| 一级毛片黄色毛片免费观看视频| 亚洲成人精品中文字幕电影| 国产精品秋霞免费鲁丝片| 一区二区三区精品91| 国产成人freesex在线| 日本黄色片子视频| 亚洲美女搞黄在线观看| 成人鲁丝片一二三区免费| 日韩一区二区三区影片| 一级爰片在线观看| 久久精品国产亚洲av涩爱| 国产精品不卡视频一区二区| 午夜精品一区二区三区免费看| 亚洲国产色片| 久久综合国产亚洲精品| 成人漫画全彩无遮挡| 国精品久久久久久国模美| 亚洲精品国产成人久久av| 女人十人毛片免费观看3o分钟| 亚洲av不卡在线观看| 亚洲最大成人中文| 一区二区av电影网| 国产精品一区www在线观看| 美女被艹到高潮喷水动态| 日韩人妻高清精品专区| 亚洲av一区综合| 麻豆成人午夜福利视频| 亚洲精品中文字幕在线视频 | 六月丁香七月| 日本爱情动作片www.在线观看| 嫩草影院新地址| 2021少妇久久久久久久久久久| 丝袜喷水一区| 两个人的视频大全免费| 观看美女的网站| 午夜爱爱视频在线播放| 欧美日韩国产mv在线观看视频 | 亚洲欧洲国产日韩| 天天躁夜夜躁狠狠久久av| 久久女婷五月综合色啪小说 | 日本熟妇午夜| 久久久午夜欧美精品| 久久人人爽av亚洲精品天堂 | 国产成人freesex在线| 国产一区二区在线观看日韩| 99久久精品国产国产毛片| 国产日韩欧美在线精品| 日韩人妻高清精品专区| 亚洲av免费在线观看| 国国产精品蜜臀av免费| 亚洲国产精品专区欧美| 亚洲精品日韩av片在线观看| 午夜福利在线观看免费完整高清在| 色网站视频免费| 在线a可以看的网站| 免费播放大片免费观看视频在线观看| 亚洲四区av| 成人欧美大片| 国内揄拍国产精品人妻在线| 一二三四中文在线观看免费高清| 麻豆精品久久久久久蜜桃| 蜜桃久久精品国产亚洲av| 中文字幕制服av| 啦啦啦啦在线视频资源| 99热6这里只有精品| 国产 精品1| 超碰97精品在线观看| 十八禁网站网址无遮挡 | 成人毛片a级毛片在线播放| 综合色av麻豆| 乱系列少妇在线播放| 观看免费一级毛片| 免费少妇av软件| 免费人成在线观看视频色| 欧美潮喷喷水| 亚洲国产精品国产精品| 日本三级黄在线观看| av黄色大香蕉| 久久久久久九九精品二区国产| a级毛片免费高清观看在线播放| 美女视频免费永久观看网站| 夜夜看夜夜爽夜夜摸| 欧美另类一区| 美女高潮的动态| 人妻 亚洲 视频| 插逼视频在线观看| 日韩av在线免费看完整版不卡| 国产一区二区三区av在线| 少妇被粗大猛烈的视频| 日本猛色少妇xxxxx猛交久久| 一边亲一边摸免费视频| 国产高清国产精品国产三级 | 国产精品国产av在线观看| 成年女人看的毛片在线观看| 亚洲av.av天堂| 久久人人爽人人爽人人片va| 午夜免费鲁丝| 婷婷色综合www| 男人爽女人下面视频在线观看| 久久99热6这里只有精品| 国产精品伦人一区二区| 乱码一卡2卡4卡精品| 日日摸夜夜添夜夜添av毛片| 高清视频免费观看一区二区| 精品熟女少妇av免费看| 嫩草影院精品99| 99久久人妻综合| 永久网站在线| 日韩成人av中文字幕在线观看| 97在线人人人人妻| 在线观看av片永久免费下载| 亚洲精品久久午夜乱码| videos熟女内射| 国产高清不卡午夜福利| 2021天堂中文幕一二区在线观| 看非洲黑人一级黄片| 亚洲国产av新网站| 啦啦啦在线观看免费高清www| 免费大片18禁| 精品久久久久久久末码| 97精品久久久久久久久久精品| 欧美97在线视频| 国产黄频视频在线观看| 男插女下体视频免费在线播放| 看黄色毛片网站| 亚洲av国产av综合av卡| 精品久久久久久久久av| 丰满少妇做爰视频| 亚洲四区av| 一级黄片播放器| 欧美 日韩 精品 国产| 亚洲三级黄色毛片| 91精品一卡2卡3卡4卡| 亚洲欧美日韩东京热| 丰满人妻一区二区三区视频av| 精品久久久精品久久久| 国产色爽女视频免费观看| 在线天堂最新版资源| 亚洲欧美精品专区久久| 在线观看一区二区三区| 亚洲综合色惰| 麻豆国产97在线/欧美| 啦啦啦中文免费视频观看日本| 一个人观看的视频www高清免费观看| 亚洲va在线va天堂va国产| 直男gayav资源| 男人舔奶头视频| 天天躁日日操中文字幕| 中国美白少妇内射xxxbb| 欧美3d第一页| 亚洲精品aⅴ在线观看| 欧美成人a在线观看| 18+在线观看网站| 成人国产av品久久久| 亚洲天堂国产精品一区在线| 日韩一区二区视频免费看| 国产毛片在线视频| 亚洲一区二区三区欧美精品 | 国产中年淑女户外野战色| 在线精品无人区一区二区三 | 春色校园在线视频观看| 亚洲天堂国产精品一区在线| 亚洲欧美一区二区三区黑人 | 在线观看av片永久免费下载| 婷婷色综合大香蕉| xxx大片免费视频| 好男人视频免费观看在线| 成人欧美大片| 搡女人真爽免费视频火全软件| 能在线免费看毛片的网站| 最近最新中文字幕大全电影3| 在线a可以看的网站| 国产一区二区三区av在线| 国产亚洲91精品色在线| 深爱激情五月婷婷| 国产 精品1| 亚洲欧美成人精品一区二区| 91午夜精品亚洲一区二区三区| 久久99热这里只有精品18| 老司机影院成人| .国产精品久久| 久久人人爽av亚洲精品天堂 | 美女脱内裤让男人舔精品视频| 69人妻影院| 人妻 亚洲 视频| 亚洲av免费在线观看| 欧美高清性xxxxhd video| 日日啪夜夜撸| 欧美xxxx黑人xx丫x性爽| 日本一本二区三区精品| 人体艺术视频欧美日本| 国产真实伦视频高清在线观看| 高清日韩中文字幕在线| 精品少妇久久久久久888优播| av女优亚洲男人天堂| 黄色欧美视频在线观看| 欧美区成人在线视频| 2022亚洲国产成人精品| 91久久精品国产一区二区三区| 久久久久久久大尺度免费视频| 亚洲精品久久久久久婷婷小说| 亚洲精品日本国产第一区| 亚洲成色77777| 嫩草影院新地址| 97超碰精品成人国产| 高清av免费在线| 老师上课跳d突然被开到最大视频| 精品国产乱码久久久久久小说| 麻豆乱淫一区二区| 亚洲精品自拍成人| av女优亚洲男人天堂| 免费观看av网站的网址| 久久国内精品自在自线图片| 成年女人看的毛片在线观看| 亚洲四区av| 人体艺术视频欧美日本| 精品久久久精品久久久| 国产成人精品福利久久| 国产av不卡久久| 简卡轻食公司| 精品人妻一区二区三区麻豆| 色网站视频免费| 久久99热这里只有精品18| 一本久久精品| 成人美女网站在线观看视频| 少妇人妻久久综合中文| 又爽又黄a免费视频| 免费观看a级毛片全部| 老司机影院成人| 国产成人freesex在线| 色哟哟·www| 日本爱情动作片www.在线观看| 波多野结衣巨乳人妻| 国产男人的电影天堂91| 亚洲久久久久久中文字幕| 美女主播在线视频| 啦啦啦啦在线视频资源| av在线蜜桃| 高清欧美精品videossex| 国产伦在线观看视频一区| 一级毛片电影观看| 久久久久网色| 成人亚洲欧美一区二区av| 一二三四中文在线观看免费高清| 中文资源天堂在线| 偷拍熟女少妇极品色| 又爽又黄a免费视频| 亚洲欧美成人综合另类久久久| 国产精品嫩草影院av在线观看| 在线精品无人区一区二区三 | 欧美少妇被猛烈插入视频| 精品99又大又爽又粗少妇毛片| 中文欧美无线码| 亚洲综合精品二区| 成人免费观看视频高清| 日日摸夜夜添夜夜爱| 成人欧美大片| 国产av不卡久久| 国产久久久一区二区三区| 久久国产乱子免费精品| 国产精品99久久99久久久不卡 | 国产老妇女一区| 天天躁日日操中文字幕| 91狼人影院| 免费电影在线观看免费观看| 欧美高清性xxxxhd video| 2022亚洲国产成人精品| av女优亚洲男人天堂| 久久久久久久久久久免费av| 免费大片18禁| 欧美日本视频| 日韩大片免费观看网站| 国产成人a区在线观看| 日日撸夜夜添| 内地一区二区视频在线| www.色视频.com| 成人无遮挡网站| 成年版毛片免费区| 18禁在线播放成人免费| 特级一级黄色大片| 午夜亚洲福利在线播放| 中文资源天堂在线| 校园人妻丝袜中文字幕| 国产91av在线免费观看| 国内揄拍国产精品人妻在线| 欧美丝袜亚洲另类| 久久久久国产精品人妻一区二区| 天天躁夜夜躁狠狠久久av| 国产人妻一区二区三区在| 免费av不卡在线播放| 国产av不卡久久| 97精品久久久久久久久久精品| 最近中文字幕2019免费版| 少妇裸体淫交视频免费看高清| 亚洲自拍偷在线| 国产高清国产精品国产三级 | 内地一区二区视频在线| 久久99蜜桃精品久久| 97精品久久久久久久久久精品| 免费观看av网站的网址| 水蜜桃什么品种好| 成人亚洲欧美一区二区av| 男插女下体视频免费在线播放| 国产有黄有色有爽视频| 亚洲婷婷狠狠爱综合网| 亚洲电影在线观看av| 69av精品久久久久久| 久久久久久久久久久免费av| 欧美性感艳星| 亚洲国产精品999| 听说在线观看完整版免费高清| 一级毛片aaaaaa免费看小| 久久久国产一区二区| 日韩 亚洲 欧美在线| 久久久久久九九精品二区国产| 国产美女午夜福利| 中文字幕av成人在线电影| 熟女人妻精品中文字幕| 交换朋友夫妻互换小说| 麻豆精品久久久久久蜜桃| 国产午夜福利久久久久久| 男男h啪啪无遮挡| 国产精品一区二区在线观看99| 少妇裸体淫交视频免费看高清| 国产一区二区三区综合在线观看 | 国产 一区精品| 中文乱码字字幕精品一区二区三区| 日本黄大片高清| 日日摸夜夜添夜夜爱| 欧美+日韩+精品| 色播亚洲综合网| av在线老鸭窝| 一区二区av电影网| 亚洲精品影视一区二区三区av| 国产 精品1| 岛国毛片在线播放| 亚洲欧洲国产日韩| 下体分泌物呈黄色| 美女被艹到高潮喷水动态| 亚洲精品,欧美精品| 亚洲av电影在线观看一区二区三区 | 天堂俺去俺来也www色官网| 亚洲无线观看免费| 超碰av人人做人人爽久久| 人人妻人人看人人澡| 国产精品爽爽va在线观看网站| 免费少妇av软件| 亚洲国产欧美人成| 国产精品麻豆人妻色哟哟久久| 亚洲精品亚洲一区二区| 男插女下体视频免费在线播放| 日韩电影二区| 国产精品无大码| 视频中文字幕在线观看| 亚洲成人一二三区av| 波野结衣二区三区在线| 久久国产乱子免费精品| 亚洲精品乱久久久久久| 中文字幕免费在线视频6| 亚洲精品乱码久久久v下载方式| 免费少妇av软件| 91aial.com中文字幕在线观看| 女人十人毛片免费观看3o分钟| av专区在线播放| 一区二区av电影网| 特大巨黑吊av在线直播| 大陆偷拍与自拍| 有码 亚洲区| 国产视频内射| 国产一区二区三区综合在线观看 | 亚洲国产欧美人成| 麻豆成人午夜福利视频| 国产日韩欧美亚洲二区| 亚洲精品日韩av片在线观看| 国产精品熟女久久久久浪| 天天一区二区日本电影三级| 99久久中文字幕三级久久日本| 亚洲av不卡在线观看| 亚洲av日韩在线播放| 日韩强制内射视频| 成年av动漫网址| 国产一区二区在线观看日韩| 如何舔出高潮| 伊人久久精品亚洲午夜| 麻豆国产97在线/欧美| 亚洲av在线观看美女高潮| 日本-黄色视频高清免费观看| 亚洲av电影在线观看一区二区三区 | 国产在视频线精品| 久久久a久久爽久久v久久| 午夜福利网站1000一区二区三区| av国产精品久久久久影院| 国产 一区 欧美 日韩| 纵有疾风起免费观看全集完整版| 亚洲,一卡二卡三卡| 在线观看人妻少妇| 99热网站在线观看| 午夜激情福利司机影院| 欧美最新免费一区二区三区| 一二三四中文在线观看免费高清| 久久精品国产亚洲av天美| av播播在线观看一区| 国产精品久久久久久精品电影小说 | 亚洲,欧美,日韩| 欧美日韩一区二区视频在线观看视频在线 | 三级经典国产精品| 夫妻午夜视频| 国产乱人偷精品视频| 免费电影在线观看免费观看| 国产成人福利小说| 欧美成人午夜免费资源| 免费观看a级毛片全部| 在线免费观看不下载黄p国产| 三级经典国产精品| 最近中文字幕高清免费大全6| 日韩电影二区| 欧美另类一区| 人妻 亚洲 视频| 噜噜噜噜噜久久久久久91| 国产乱人偷精品视频| 久久久久久久久大av| 国产人妻一区二区三区在| 欧美精品一区二区大全| 国产免费视频播放在线视频| 国产大屁股一区二区在线视频| 五月玫瑰六月丁香| 极品教师在线视频| 少妇丰满av| 一级av片app| 国产一区二区三区av在线| 好男人在线观看高清免费视频| 亚洲第一区二区三区不卡| 免费观看无遮挡的男女| 在线精品无人区一区二区三 | av.在线天堂| 亚洲av日韩在线播放| 亚洲精品国产成人久久av| 午夜精品一区二区三区免费看| eeuss影院久久| 少妇人妻精品综合一区二区| 国产午夜福利久久久久久| 国产高清有码在线观看视频| 成人一区二区视频在线观看| 久久久成人免费电影| 男男h啪啪无遮挡| 国产色爽女视频免费观看| 日韩中字成人| 乱系列少妇在线播放| 九九在线视频观看精品| 国产一区二区在线观看日韩| 色视频在线一区二区三区| av在线app专区| 日韩av在线免费看完整版不卡| 欧美激情在线99| 看黄色毛片网站| 啦啦啦在线观看免费高清www| 成年av动漫网址| 日本色播在线视频| 亚洲精品中文字幕在线视频 | 十八禁网站网址无遮挡 | 内地一区二区视频在线| 免费播放大片免费观看视频在线观看| 97精品久久久久久久久久精品| 欧美日韩一区二区视频在线观看视频在线 | 午夜福利在线观看免费完整高清在| 一级a做视频免费观看| 99热这里只有精品一区| 午夜日本视频在线| 亚洲四区av| 欧美区成人在线视频| 欧美少妇被猛烈插入视频| 国产成人a区在线观看| 国产一区二区在线观看日韩| 久久久久性生活片| 国产极品天堂在线| 免费观看的影片在线观看| 国产黄片美女视频| 校园人妻丝袜中文字幕| 老师上课跳d突然被开到最大视频| 99久久中文字幕三级久久日本| 男女无遮挡免费网站观看| 九色成人免费人妻av| 国产精品国产av在线观看| 欧美性感艳星| 国内精品美女久久久久久| 国产乱来视频区| 亚洲精品色激情综合| 国产探花在线观看一区二区| 精品久久久久久久末码| 夜夜看夜夜爽夜夜摸| 成人二区视频| 日产精品乱码卡一卡2卡三| 亚洲人与动物交配视频| 日韩欧美精品v在线| 亚洲va在线va天堂va国产| 国产一区二区三区综合在线观看 | 日韩一本色道免费dvd| 一区二区三区四区激情视频| 国产成人午夜福利电影在线观看| 欧美另类一区| 久久久a久久爽久久v久久| 又大又黄又爽视频免费| 99热这里只有是精品在线观看| 亚洲精品日韩av片在线观看| 51国产日韩欧美| 亚洲欧美精品自产自拍| 中国国产av一级| 国产精品99久久久久久久久| 国国产精品蜜臀av免费| 联通29元200g的流量卡| 亚洲最大成人av| 人妻 亚洲 视频| 国产男女内射视频| 乱码一卡2卡4卡精品| 99热网站在线观看|