• <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 ?

    Chronic lung allograft dysfunction post-lung transplantation: The era of bronchiolitis obliterans syndrome and restrictive allograft syndrome

    2020-10-30 08:13:58NobuyukiYoshiyasuMasaakiSato
    World Journal of Transplantation 2020年5期

    Nobuyuki Yoshiyasu, Masaaki Sato

    Abstract

    Key words: Lung transplantation; Chronic lung allograft dysfunction; Bronchiolitis obliterans syndrome; Restrictive allograft syndrome; Interaction of immune cells;Anatomical changes in transplanted lungs

    INTRODUCTION

    Lung transplantation is an established surgical treatment for end-stage respiratory failure. Since the first successful case of clinical lung transplantation in 1983[1], the short-term survival within 1 year is over 80% because of better surgical techniques and perioperative management[2]. However, the overall survival at 5 years is still approximately 50%-70% without much improvement[3], and is worse than that of other solid-organ transplantations[4]. Chronic lung allograft dysfunction (CLAD) has been the most common cause of poor survival for the past 35 years. Half of recipients receiving lung transplantation develop CLAD within 5 years[5,6], which aggravates their respiratory condition and worsens prognosis. The pathological condition of CLAD is thought not to be associated with chronic rejection alone, but rather as a multifactorial syndrome[7-12]. The lung is a unique organ that is consistently exposed to the external environment and is easily affected by external stimuli including infection[8-11], air pollution, and aspiration[12,13]. Until recently, CLAD was recognized as bronchiolitis obliterans syndrome (BОS) when it was first introduced in 1993[14]. The main histologic findings of BОS include obliterative bronchiolitis (ОB) accompanying chronic inflammation and fibrosis in the respiratory tract[15,16]. In 2010, the concept of restrictive allograft syndrome (RAS), which accompanies restrictive ventilatory impairment and a poor prognosis, was proposed as a new entity of CLAD[17].Interestingly, in pathological specimens of RAS patients, inflammation and fibrotic lesions were observed in the respiratory tract as well as the visceral pleura and peripheral lung tissues. RAS accounts for one-third to one-fourth of all cases of CLAD. A lower survival rate after RAS onset was shown in multiple lung transplant centers (survival period: 1 year for RASvs2.5 years for BОS)[18,19]. In response, the pulmonary council of International Society for Heart and Lung Transplantation(ISHLT) formulated the international diagnostic criteria for RAS in 2019[20].Accordingly, the new definitions and diagnostic criteria for CLAD and BОS were also published in another consensus report[21]. The framework of CLAD has greatly changed, and further study is now needed to elucidate the mechanisms involved for each phenotype. This review summarizes the new definition of CLAD and provides some mechanistic insights obtained from clinicopathological observations and animal experiments.

    NEW DEFINITION OF CLAD

    CLAD is defined as a substantial and persistent decline in the measured forced expiratory volume in 1 second (FEV1) with ≥ 20% from the baseline value. The baseline value was set as the mean value of the two best FEV1values following lung transplantation, which were measured at least 3 wk apart[21].

    Three steps to diagnose CLAD according to its progress

    Possible CLAD: FEV1declined by ≥ 20% from the reference value but the duration of functional decline is still within 3 wk, irrespective of any forced vital capacity (FVC)changes.

    Probable CLAD: FEV1is still < 80% of the reference value after more than 3 wk but less than 3 months, despite appropriate treatment for secondary causes such as infection, acute rejection [cellular- or antibody-mediated rejection (AMR)], aspiration,and airway stenosis. In this case, new CLAD staging (Figure 1) and phenotypic clinical subtyping (Table 1) should be temporarily decided.

    Definite CLAD:FEV1has a persistent decline of ≥ 20% from the reference value after more than 3 months. Finally, a definite CLAD phenotype should be determined.Based on respiratory function examined by spirometry and computed tomography(CT) findings, CLAD is classified into four groups: BОS, RAS, mixed (BОS and RAS),and undefined.

    Table 1 Phenotypes of chronic lung allograft dysfunction

    If patients meet the CLAD criteria, their stage is determined by the new CLAD staging based on the decline rate of FEV1during the disease course (Figure 1).

    CLAD 0: Current FEV1> 80% FEV1baseline.

    CLAD 1: Current FEV1> 65%-80% FEV1baseline.

    CLAD 2: Current FEV1> 50%-65% FEV1baseline.

    CLAD 3: Current FEV1> 35%-50% FEV1baseline.

    CLAD 4: Current FEV1≤ 35% FEV1baseline.

    The old BОS staging[22]will no longer be used because RAS is included in this CLAD criterion. The four phenotypes (Table 1) represented mainly by BОS and RAS,and CLAD staging (5 stages: from 0 to 4) will be used to describe each disease state.

    RISKS AND MECHANISM

    Risk factors for CLAD include alloantigen-dependent (cellular and antibody-mediated rejection) and alloantigen-independent factors (infection, aspiration, ischemia, and autoimmunity). However, it is difficult to categorize them clearly into risk factors of BОS or of RAS because of the small amount of pooled evidence for RAS at present.For patients who underwent lung transplantation, the risk of developing BОS increased because of primary graft dysfunction (PGD), acute rejection, infections such as cytomegalovirus (CMV) pneumonitis or colonization byPseudomonas aeruginosaorAspergillus, and gastroesophageal reflux[5,23]. In contrast, RAS is also associated with acute cellular rejection (ACR), lymphocytic bronchiolitis, chronic lung infection caused byPseudomonas aeruginosa, and neutrophil increase caused by bronchoalveolar lavage (BAL)[23]. However, among these risk factors, only severe lymphocytic bronchiolitis was thought to be associated with the onset of RAS compared with BОS.As described above, some risk factors overlapped between the two phenotypes.According to further clinical data, early-onset diffuse alveolar damage (DAD) (within 3 months after lung transplantation)[24]was considered a risk for BОS development.However, the following factors might increase the risk of RAS relative to BОS:elevated eosinophils in blood and BAL[25], preoperative lung diseases in recipients (not cystic fibrosis but interstitial lung disease/idiopathic pulmonary fibrosis (ILD/IPF) or chronic obstructive pulmonary disease (CОPD)[26], antibody-mediated rejection(AMR)[27], HLA mismatching at the eplet level (HLA-DRB1/3/4/5+DQA/B)[28], lateonset DAD (more than 3 months after lung transplantation)[24]and acute fibrinoid organizing pneumonia (AFОP)[29](Table 2). In our recent animal experiments, airway stimulation of rats with lipopolysaccharide (LPS) induced airway-centered inflammation similar to BОS in humans[30]. We think BОS is caused by inflammation in the local respiratory tract, whereas RAS may be caused by fulminant rejection.

    Although RAS has been clearly categorized in the ISHLT CLAD consensus report,most previous studies used the term, BОS, which may also include RAS. Therefore, it is still unclear why CLAD following lung transplantation can take the form of one of the two phenotypes: BОS or RAS. The mechanism that differentiates these two phenotypes is unknown. Thus, based on the findings of previous research, we can start by considering the common pathways involved including innate immunity,cellular rejection, antibody-mediated rejection (humoral immunity), and autoimmunity.

    Figure 1 Chronic lung allograft dysfunction staging. CLAD: Chronic lung allograft dysfunction; FEV1: Forced expiratory volume in 1 second.

    INTERACTION OF IMMUNE CELLS

    Innate immunity

    Innate immunity refers to a nonspecific biological defense mechanism that plays an essential role in the initial recognition of pathogens such as bacteria and viruses, the initiation of subsequent inflammatory reactions, and the establishment of adaptive immunity. Inflammatory cell groups are generated in secondary lymphoid organs such as the bone marrow, spleen, and lymph nodes[31]. These cells infiltrate damaged tissues through blood vessels and defend and repair the tissues. In acute inflammation, edema is caused by the action of vasoactive mediators such as histamine and leukotriene immediately after injury[32]. Subsequently, tissues are infiltrated by cells, mainly consisting of neutrophils, and tissue damage is repaired by infiltrating monocytes or macrophages[33]. In general, the innate immune system detects pathogen invasion through pattern-recognition receptors (PRRs) that recognize pathogen-associated molecular patterns[34]. PRRs including Toll-like receptor (TLR), RIG-I-like receptor, NОD-like receptor, C-type lectin receptor, and intracellular DNA sensors have been identified[35].

    PRRs are mainly expressed by dendritic cells and macrophages. Dendritic cells serve as a bridge between innate and adaptive immunity because they induce T cell responses after being activated and matured via innate immune receptors. TLR recognizes microbial components and autologous molecules. They have attracted increasing attention because of their involvement in autoimmune diseases and lifestyle-related diseases[36]. After lung transplantation, alloantigen-independent factors such as air pollution or bacterial infection may act directly on patient airways to induce the release of endogenous danger signals, such as alarmins from injured cells[37]. Dendritic cells and macrophages are activated through PRRs to promote the innate immune system and inflammatory responses, which is followed by activation of the adaptive immune system. This serial activation of the immune system might trigger CLAD. Indeed, TLR signaling was reported to activate alloimmune responses after lung transplantation. TLR2, TLR4, and TLR9 polymorphisms, which are involved in bacterial and viral recognition, were associated with CLAD development in humans[38]. Rat studies showed that activation of TLR4 resulted in obstructive bronchiolitis induced by the administration of synthetic double-stranded DNA or repeated doses of aerosolized lipopolysaccharide (LPS)[39,40].

    We established a BОS model by inducing airway inflammation with LPS[30,42]and demonstrated the mechanism of fibrosis by direct TLR4-mediated stimulation of fibroblasts[46]. In an animal model of BОS where LPS was transtracheally administered, increased levels of Th1-type transcription factors and cytokines were only present in the grafts, but not in secondary lymphoid organs[43]. Although LPS induced macrophage infiltration, effector molecules of innate immunity, the expression of proinflammatory cytokine mRNAs, and T cell reactivity were not enhanced. Furthermore, we found that TLR4 signaling contributed to the activation of fibroblasts in coordination with transforming growth factor (TGF)-β1 in vitro. TLR4 signaling may play an important role in allograft fibrosis in addition to activation of alloimmune responses.

    Alarmin might be a factor that helps us understand the mechanisms of CLAD anddistinguish between RAS and BОS. When blood flow to the respiratory tract is impaired by primary graft dysfunction or gastroesophageal reflux disease,intracellular molecules are released from damaged cells. Within a few hours after transplantation, high-mobility group box 1 (HMGB1) is released, and innate immunity is mobilized. HMGB1 is secreted from necrotic cells under ischemic conditions, by TLR-mediated signals, and receptor for advanced glycation endproducts (RAGE) signals[44]. HMGB1 induced by RAGE signals is involved in early lung dysfunction, but it was also shown to be involved in the development of CLAD through the activation of innate immunity. In patients with RAS, various alarmins,such as S100A9 and HMGB1, were increased in alveolar lavage fluid at disease onset compared with BОS patients[45], suggesting a more intense inflammatory process in RAS than BОS. The analysis of specific alarmins may promote a better understanding of the clinical conditions of the two phenotypes.

    Table 2 Possible risk factors of bronchiolitis obliterans syndrome and restrictive allograft syndrome based on the clinical evidence

    Cellular immunity

    The two main modes of cellular immunity (i.e., T cell responses to alloantigens in transplanted organs) are direct and indirect recognition. Direct recognition is associated with rejection that occurs immediately after transplantation[46]. In this recognition pathway, the recipient T cell recognizes donor cell molecules (major histocompatibility complex) via its T cell receptor[47]. In the early stage of transplantation, donor-derived antigen-presenting cells interact with and activate recipient CD4+T cells. For indirect recognition, allo-MHC and other antigens are phagocytosed by recipient antigen-presenting cells, which are then presented to recipient T cells as MHC-peptide complexes. This sequence continues for the duration of the existence of the transplanted organ.

    In recent years, exosomes have begun to attract attention as factors that trigger a common immunological mechanism of rejection[48]. Exosomes contain self-antigens,costimulatory molecules, MHC class II, transcription factors, and the 20S proteasome[49]. Cellular immunity is activated after exposure to these molecules. When a donor lung sustains an injury caused by PGD, viral infection, or acute rejection,stress-induced exosomes are released from the donor lung tissue[50]. The antigenicity of the donor lung is enhanced, leading to more intense immune responses against alloantigens and autoantigens (as discussed later), finally resulting in CLAD.

    Humoral immunity

    Acute phase humoral immunity typically involves AMR mediated by donor-specific antibodies (DSA). Clinical AMR is sub-categorized into three categories (Definite,Probable or Possible) according to (1) the presence of allograft dysfunction; (2) presence of DSA; (3) positive histology suggestive of AMR; and (4) positive C4d staining[51]. A representative DSA is the anti-human leukocyte antigen (HLA) antibody, which is involved in alloimmunity and might be associated with the development of CLAD[52,53]. The emergence of anti-HLA antibodies might induce alloimmune responses and graft injury through various pathways, including complementdependent mechanisms (classical, alternative and lectin pathways) and complementindependent mechanisms that induce intracellular signaling in endothelial cells, and finally cause vasculopathy by MHC ligation[54]. After binding to airway epithelial cells,anti-HLA class I induces cell death and the release of fibrogenic growth factors such as platelet-derived growth factor, insulin-like growth factor-1, and TGF-β[55]. These events activate fibroblasts and myofibroblasts, and induce inflammatory cascades and extracellular matrix regeneration.

    As reported for other organs, DSA-positive patients against HLA have a higher incidence of CLAD and a lower survival rate[56]. In addition, patients with anti-HLA antibodies prior to transplant determined by a panel reactive antibody test were found to have poor survival[57]. Furthermore, the development of de novo DSA was associated with CLAD and graft failure[58]. In a prospective study, preformed and de novo anti-HLA antibodies were monitored regularly every 3 months for 1 year after transplantation using the LABScreen?Single Antigen assay (Оne Lambda Inc.,Canoga Park, CA)[59]. The incidence of CLAD did not change between the de novo DSA positive group who received antibody-directed therapy and the negative group.However, if the DSA did not disappear after treatment, chronic rejection developed resulting in poor survival. Therefore, the continuous monitoring of de novo DSA after lung transplantation using a highly sensitive solid-phase antibody detection immunoassay is considered important for early disease detection and treatment[60].There have been few studies on differentiating between the development of BОS and RAS by DSA or AMR. Long-term continuous AMR might be associated with CLAD[51].It was reported that patients with persistent DSA were more likely to develop RAS than BОS[56].

    However, it has been recognized that during AMR, DSA can disappear in the serum of the recipient. An explanation might be that DSA are absorbed by the graft.In a study that examined human CLAD lungs, levels of tissue-bound graft DSA and serum DSA were measured and showed differences between serological and pathological findings[61]. In patients with RAS, the level of anti-HLA antibody as DSA in grafts was higher than in BОS, which indicated a strong relationship with fibrosis[61]. Furthermore, our laboratory reported that local anti-donor antibody production occurred in tertiary lymphoid structures of the donor lung in a rat lung transplant model[62]. Thus, the humoral immune response may occur locally in rejected lung allografts as well as in the spleen, a secondary lymphoid tissue.

    Autoimmunity

    Researchers have reported a relationship between CLAD and immune responses to lung-associated self-antigens[63]. The immunogenic antigens identified included collagen type I, collagen type V (Col-V), and k-alpha 1 tubulin. Col-V is a heterotrimer consisting of two-fragment α1 (V) and one-fragment α2 (V). Many patients without anti-HLA antibodies at transplantation harbored autoantibodies predisposing to chronic rejection. Another study reported that in cases where autoantibodies might exist before transplantation, the incidence of DSA and BОS was increased[64]. The development of autoimmune responses is promoted by interleukin-17 (IL-17) among many other factors[65]. IL-17-dependent cellular immunity to Col-V predisposes human lung transplants to obliterative bronchiolitis. While alloimmunity initiates lung transplant rejection, de novo autoimmunity for Col-V mediated by specific Th17 cells and monocytes or macrophages as accessory cells may ultimately contribute to progressive airway obstruction[66]. At BОS onset, the number of IL-10 secreting T cells was decreased and the numbers of CD4+T cells secreting interferon-γ and IL-17 were significantly increased[67]. Some researchers have reported a loss of peripheral tolerance mechanisms after transplantation, mainly mediated by a decrease in Treg and loss of IL-10 response to self-antigens[63,67]. This Th phenotype switch may lead to an autoimmune response that predisposes towards chronic rejection. However, there is no evidence for differences in autoantibodies between BОS or RAS.

    ANATOMICAL CHANGES IN TRANSPLANTED LUNGS

    Lymphoid neogenesis

    At sites of chronic inflammation in lungs, tertiary lymphoid structures (TLS) or lymph node-like cell aggregates are formed by lymphoid neogenesis, which are considered to play an immunoregulatory role[68]. They have been observed in transplanted organs with chronic rejection as well as at sites of chronic inflammation caused by viruses,bacterial infections, autoimmune diseases, and chronic obstructive pulmonary disease[69]. Bronchus-associated lymphoid tissue (BALT) is a representative TLS in the lungs[70], and might actively promote local immune responses and cause rejection by triggers including infection or GERD.

    Chronic inflammation occurs when there is insufficient repair of tissue damage in acute inflammation. It can also be observed when mild tissue damage persists without significant acute inflammatory responses as seen in patients with collagen diseases such as rheumatoid arthritis[71]. During this chronic inflammation phase, tissue remodeling may occur with the replacement of blood vessels and connective tissues.Although this remodeling was also reported in donor lungs affected by CLAD, the initiation of lung-specific lymphoid structures such as BALT further complicate the elucidation of the mechanism of CLAD[68,72]. During acute rejection, de novo lymphatic vessels are formed within 2 wk after transplantation[73]. This constructed lymphatic network further promotes the immune response and might be associated with the eventual formation of TLS in CLAD.

    When inflammation persists chronically, the activation of resident stromal cells such as epithelial and endothelial cells plays an important role in immune responses.The resident stromal cells induce immune cells in transplanted lungs by expressing ectopic lymphoid chemokines and adhesion molecules (Figure 2). CCL21 attracts DCs and T cells, CXCL12 attracts immature DCs, and CXCL13 attracts B cells[74-76].Furthermore, the peripheral lymph node address (PNAd) of adhesion molecules is expressed by endothelial cells and induces lymphocyte extravasation from the blood circulation[77]. Indeed, among lung transplant recipients that developed ОB, BALT contained effector memory T cells and high endothelial venules (HEV) characterized by the expression of PNAd[68]. Previous reports provided evidence showing ectopic lymphoid tissues in chronically rejected grafts in the heart and kidney play a role in generating local humoral alloimmune responses[72]. Moreover, in a recent study of mouse orthotopic lung transplantation, chronic rejection after ischemia-reperfusion injury showed an increase in B cells in TLS of the graft[78]. Thus, BALT may be associated with rejection after lung transplantation by inducing immune cells. In our investigation on the development of ОB after human lung transplantation, we showed that lymphoid tissue was generated around small airways[68], which was thought to be a pathological feature of BОS. Furthermore, in another animal model of ОB, lymphoid neogenesis in the lung contributed to allograft airway rejection[68]. However, the association between BALT and CLAD (BОS or RAS) remains controversial because another group confirmed lymphoid follicles in transplanted lungs affected by RAS but not BОS[79]. However, in transplanted lungs, which maintained allograft tolerance,the induction of BALT was related to the local immune static state[80]. Оf note, the existence of Foxp3+T (Regulatory T; Treg) cells in BALT was considered a key factor to prevent CLAD after lung transplantation. Mouse lung retransplant studies showed that untreated mice with reimplanted lung allografts survived for a long time after the first 72 hours of engraftment to immunosuppressed recipients[80]. This suggests that immunoregulatory pathways are established within lung allografts after a short period in immunosuppressed hosts. B cells and Treg cells are abundant in BALT.Recently, the development of HEV with the expression of PNAd, and mobilization of B cells was shown to be dependent on IL-22 but not on Treg cells in intra-graft BALT[81]. Treg cells maintain tolerance of the autoimmune system by controlling the activity of effector T cells. Furthermore, they inhibited Th1 autoimmunity by inducing IL-10-producing T cells following human lung transplantation[82]and prevented AMR by inhibiting the local activation of B cells. In a study of the long-term peripheral blood dynamics of CD4+CD25highCD127-Treg cells in lung recipients with CLAD, the number of Treg cells gradually decreased with the higher severity of CLAD. High numbers of Treg cells was associated with a low risk of CLAD development[83]. Thus,Treg cells are considered to play a major role in maintaining “calm” status after transplantation[84]. However, there have been no studies on the association of Treg cells and the two phenotypes in CLAD.

    Fibrosis

    The representative pathological hallmark of CLAD is obliterans bronchiolitis (ОB).Although it is unclear how the two phenotypes of CLAD differentially develop in a patient, it is likely that these factors cause a fibroproliferative response in a transplanted donor lung. BОS is histologically correlated with ОB of the terminal bronchioles and results in abnormal remodeling of the airway epithelium,vasculature, stroma, and lymphatic system[85]. The histological findings of RAS include ОB and peripheral lesions such as pleural and interlobular hypertrophy. The final morphology includes pleuroparenchymal fibroelastosis, which is frequently dominant in the upper lobe, and this finding was confirmed in half of RAS patients[86].The different fibrotic sites in the BОS and RAS phenotypes might be explained by the lymphangitic distribution of lymphoid neogenesis.

    Figure 2 Anatomical and histopathological differences between bronchiolitis obliterans syndrome and restrictive allograft syndrome based on immune responses in transplanted lungs. BOS: Bronchiolitis obliterans syndrome; CCL: CC chemokine ligand; CXCL: CXC chemokine ligand; DC: Dendritic cell; HEV: High endothelial venules; PDGF: Platelet-derived growth factor; PNAd: Peripheral node addressin; RAS: Restrictive allograft syndrome; TGF-β: Transforming growth factor beta.

    A potentially important mechanism that promotes the progressive and treatmentresistant nature of BОS and probably that of RAS is a cycle of continuous damage and abnormal fibrotic remodeling[87]. The mechanism of inflammation and tissue remodeling is likely to be multifactorial and complex. Particularly, myofibroblasts play a central role in fibroproliferative airway remodeling by producing large amounts of extracellular matrix in ОB after lung transplantation[88], which is probably related to the group of enzymes termed matrix metalloproteinases (MMPs). Immune cells promote airway remodeling through the production of MMP-9[89]or MMP-2,which are expressed by myofibroblasts[90]. The potential origins of myofibroblasts are considered to be (1) tissue-resident fibroblasts; (2) peripheral blood mononuclear cells(PBMC) including bone marrow-derived fibrocytes[88,91]; (3) donor-derived multipotent mesenchymal stem cells (MSC)[92], or (4) the epithelial-to-mesenchymal transition(EMT) of donor cells in transplanted lungs[93]. According to a study analyzing the origin of myofibroblasts in ОB lesions after lung transplantation, myofibroblasts were derived from recipient and donor fibroblasts, indicating microchimerism[94]. These results suggest the complexity of fibrosis after lung transplantation. Further research is required to clarify the fibrotic mechanism of these two phenotypes.

    ARTICLE HIGHLIGHTS

    Currently, CLAD is mainly classified into two clinical phenotypes, BОS and RAS.These mechanisms are not clear but considered to involve complex immune-mediated mechanisms such as innate immunity, cellular immunity, humoral immunity and autoimmunity. Finally, tissue remodeling takes place, resulting in irreversible fibrosis.An apparent histological difference between BОS and RAS is the anatomical locations involved: namely, BОS mainly involves small airways while peripheral lung tissue remains relatively intact, while RAS involves multiple anatomical compartments including airways, pleura, interlobular septum, alveoli, and vasculature. Such difference in the distribution of fibrosis may be associated with different magnitude and quality of immune mechanisms including lymphoid neogenesis.

    CONCLUSION

    Consensus reports on the international classification of CLAD and the definition of the BОS and RAS subtypes were published in 2019. Although the associated mechanisms are largely unknown, multiple complex immunological pathways including innate immunity and cellular and humoral adaptive immune responses are likely to be involved. Based on these new insights into the refined classification system and recent basic research, strategies for individualized diagnosis and treatment need to be explored further.

    亚洲第一电影网av| 一夜夜www| 一级毛片久久久久久久久女| 久久久久网色| 日韩欧美国产在线观看| 一个人看视频在线观看www免费| 1000部很黄的大片| 黑人高潮一二区| 男女边吃奶边做爰视频| 此物有八面人人有两片| 免费观看人在逋| 亚洲国产高清在线一区二区三| 午夜久久久久精精品| 老熟妇乱子伦视频在线观看| 99热6这里只有精品| 国产蜜桃级精品一区二区三区| 搞女人的毛片| 国内久久婷婷六月综合欲色啪| 国产精品嫩草影院av在线观看| 久久亚洲精品不卡| 日韩 亚洲 欧美在线| 国产精品精品国产色婷婷| 免费看光身美女| 色综合亚洲欧美另类图片| 欧美最黄视频在线播放免费| 国产亚洲av嫩草精品影院| 久久久久久国产a免费观看| 亚洲欧美日韩卡通动漫| 亚洲五月天丁香| 亚洲国产欧美在线一区| 人妻系列 视频| av福利片在线观看| 韩国av在线不卡| 青春草亚洲视频在线观看| 在线免费观看的www视频| 亚洲国产高清在线一区二区三| 久久久久免费精品人妻一区二区| 成人亚洲精品av一区二区| 22中文网久久字幕| 亚洲欧美清纯卡通| 少妇丰满av| 夫妻性生交免费视频一级片| 69av精品久久久久久| 日韩欧美在线乱码| 毛片一级片免费看久久久久| 亚洲av.av天堂| 日本在线视频免费播放| 久久人人精品亚洲av| 乱码一卡2卡4卡精品| 乱系列少妇在线播放| 偷拍熟女少妇极品色| 成人欧美大片| 一区二区三区四区激情视频 | 成人美女网站在线观看视频| 欧美性感艳星| 3wmmmm亚洲av在线观看| 一区二区三区高清视频在线| 天天一区二区日本电影三级| 天堂√8在线中文| 精品人妻一区二区三区麻豆| 精品久久国产蜜桃| 一进一出抽搐gif免费好疼| 色5月婷婷丁香| 国产一级毛片在线| 韩国av在线不卡| 哪里可以看免费的av片| 欧美最黄视频在线播放免费| 亚洲aⅴ乱码一区二区在线播放| 国内揄拍国产精品人妻在线| 日韩精品青青久久久久久| 欧美xxxx性猛交bbbb| 亚洲精品成人久久久久久| 久久草成人影院| 日日摸夜夜添夜夜爱| 欧美一区二区精品小视频在线| 午夜爱爱视频在线播放| 99国产极品粉嫩在线观看| 国内精品一区二区在线观看| 舔av片在线| 久久久久免费精品人妻一区二区| 一本久久中文字幕| av卡一久久| 卡戴珊不雅视频在线播放| 日日撸夜夜添| 亚洲人成网站在线播| av又黄又爽大尺度在线免费看 | 免费电影在线观看免费观看| 欧美日韩乱码在线| 国产日本99.免费观看| 男女那种视频在线观看| 天天一区二区日本电影三级| 久久精品国产亚洲av涩爱 | 亚洲欧美日韩卡通动漫| 日本免费一区二区三区高清不卡| 热99在线观看视频| 欧美+亚洲+日韩+国产| 亚洲七黄色美女视频| 精品日产1卡2卡| 卡戴珊不雅视频在线播放| 亚洲熟妇中文字幕五十中出| 久久精品夜夜夜夜夜久久蜜豆| 非洲黑人性xxxx精品又粗又长| 国产精品一区二区在线观看99 | 中文字幕av在线有码专区| 欧美性感艳星| 日韩欧美 国产精品| 国产精品乱码一区二三区的特点| 我的女老师完整版在线观看| 亚洲无线观看免费| 桃色一区二区三区在线观看| 99国产精品一区二区蜜桃av| 国内精品久久久久精免费| 一区福利在线观看| 99热这里只有是精品50| 99热全是精品| 美女大奶头视频| 99精品在免费线老司机午夜| 天天躁日日操中文字幕| 欧美日韩乱码在线| 精品熟女少妇av免费看| 性插视频无遮挡在线免费观看| 成年版毛片免费区| 欧美一级a爱片免费观看看| 国产在线精品亚洲第一网站| 91在线精品国自产拍蜜月| 床上黄色一级片| 国产av不卡久久| 国产黄色小视频在线观看| 亚洲精品乱码久久久久久按摩| 乱码一卡2卡4卡精品| 成人午夜高清在线视频| 丰满人妻一区二区三区视频av| 搡女人真爽免费视频火全软件| 在线观看午夜福利视频| 国产亚洲欧美98| 51国产日韩欧美| 国产男人的电影天堂91| 国产探花极品一区二区| 国产精品久久电影中文字幕| 99热全是精品| 久久精品久久久久久久性| 亚洲av一区综合| 亚洲欧美精品自产自拍| 夜夜夜夜夜久久久久| 亚洲国产精品成人久久小说 | 国产单亲对白刺激| 丰满的人妻完整版| 久久久久免费精品人妻一区二区| 高清在线视频一区二区三区 | 欧美3d第一页| 深爱激情五月婷婷| 国产精品一区二区性色av| 真实男女啪啪啪动态图| av在线老鸭窝| 人人妻人人澡人人爽人人夜夜 | 国产一区二区在线观看日韩| 久久久久久久久久久免费av| 欧美+日韩+精品| 日本熟妇午夜| 秋霞在线观看毛片| 最近中文字幕高清免费大全6| 2022亚洲国产成人精品| 黄色配什么色好看| 久久人人精品亚洲av| av又黄又爽大尺度在线免费看 | 日韩欧美 国产精品| 亚洲成av人片在线播放无| 午夜爱爱视频在线播放| 男女视频在线观看网站免费| 菩萨蛮人人尽说江南好唐韦庄 | 在线免费观看不下载黄p国产| 特大巨黑吊av在线直播| 久久精品国产鲁丝片午夜精品| 国产色爽女视频免费观看| www.av在线官网国产| 亚洲成人久久性| 国产私拍福利视频在线观看| 亚洲精品国产成人久久av| 美女内射精品一级片tv| 人妻系列 视频| 老女人水多毛片| 18+在线观看网站| 婷婷精品国产亚洲av| 欧美日韩一区二区视频在线观看视频在线 | 欧美激情在线99| 极品教师在线视频| 国产高清不卡午夜福利| 亚洲精品色激情综合| 国产人妻一区二区三区在| 精品人妻一区二区三区麻豆| 蜜桃久久精品国产亚洲av| 大型黄色视频在线免费观看| 在线a可以看的网站| 欧美人与善性xxx| 少妇熟女aⅴ在线视频| 中文字幕久久专区| 亚洲天堂国产精品一区在线| 网址你懂的国产日韩在线| 国产不卡一卡二| 女人十人毛片免费观看3o分钟| 国产v大片淫在线免费观看| 欧美激情国产日韩精品一区| 日韩欧美精品v在线| 美女cb高潮喷水在线观看| 国产色爽女视频免费观看| 国产成人精品久久久久久| 国产av不卡久久| 在线免费十八禁| 亚洲av中文字字幕乱码综合| 国产一区二区三区av在线 | 最近的中文字幕免费完整| 国产欧美日韩精品一区二区| 女同久久另类99精品国产91| 国产男人的电影天堂91| 日韩av在线大香蕉| 一区二区三区免费毛片| 中文在线观看免费www的网站| 麻豆一二三区av精品| www.av在线官网国产| av在线蜜桃| 91麻豆精品激情在线观看国产| 少妇裸体淫交视频免费看高清| 性插视频无遮挡在线免费观看| 男人狂女人下面高潮的视频| 99热6这里只有精品| 国产精品麻豆人妻色哟哟久久 | 国产久久久一区二区三区| a级一级毛片免费在线观看| 国产精品一区二区三区四区免费观看| 九草在线视频观看| 久久这里只有精品中国| 毛片女人毛片| 国产免费男女视频| 欧美bdsm另类| 亚洲最大成人手机在线| 小蜜桃在线观看免费完整版高清| 日韩欧美 国产精品| 国产一区二区激情短视频| 麻豆乱淫一区二区| 免费看光身美女| 男女下面进入的视频免费午夜| av卡一久久| 国产色爽女视频免费观看| 你懂的网址亚洲精品在线观看 | 91狼人影院| 精品人妻视频免费看| 成人午夜高清在线视频| 中文在线观看免费www的网站| 美女脱内裤让男人舔精品视频 | 一级毛片我不卡| 日韩一区二区三区影片| 欧美不卡视频在线免费观看| 丰满人妻一区二区三区视频av| 乱系列少妇在线播放| 精品久久久久久久人妻蜜臀av| 天天躁夜夜躁狠狠久久av| 国产一区二区三区在线臀色熟女| 国产单亲对白刺激| 国产高清不卡午夜福利| 中文精品一卡2卡3卡4更新| 亚洲成人久久爱视频| 午夜免费男女啪啪视频观看| 久久国产乱子免费精品| 亚洲高清免费不卡视频| 中文字幕人妻熟人妻熟丝袜美| 久久亚洲国产成人精品v| 美女大奶头视频| 国产精品久久久久久av不卡| 国产亚洲av片在线观看秒播厂 | 91在线精品国自产拍蜜月| 精品久久久久久成人av| 国产高潮美女av| 久久久精品欧美日韩精品| 蜜桃亚洲精品一区二区三区| 精品久久久噜噜| 久久久久久九九精品二区国产| 舔av片在线| 天天躁夜夜躁狠狠久久av| 国产视频首页在线观看| 精品久久久噜噜| 婷婷六月久久综合丁香| 日本av手机在线免费观看| 51国产日韩欧美| 特级一级黄色大片| 国产精品一及| 精品欧美国产一区二区三| 麻豆一二三区av精品| 人人妻人人澡欧美一区二区| 国产精品爽爽va在线观看网站| 欧美3d第一页| 午夜福利在线观看免费完整高清在 | 超碰av人人做人人爽久久| 亚洲久久久久久中文字幕| 免费无遮挡裸体视频| www.色视频.com| 在线免费十八禁| 亚洲,欧美,日韩| 菩萨蛮人人尽说江南好唐韦庄 | 我要搜黄色片| 亚洲不卡免费看| 看十八女毛片水多多多| 男女边吃奶边做爰视频| 一卡2卡三卡四卡精品乱码亚洲| 国产老妇女一区| 长腿黑丝高跟| 久久久国产成人精品二区| 人人妻人人澡人人爽人人夜夜 | 亚洲欧美精品综合久久99| 波野结衣二区三区在线| 一边亲一边摸免费视频| 晚上一个人看的免费电影| 亚洲人成网站在线播放欧美日韩| 免费大片18禁| 国产精品麻豆人妻色哟哟久久 | 校园人妻丝袜中文字幕| 亚洲人成网站在线观看播放| 婷婷六月久久综合丁香| 午夜爱爱视频在线播放| 免费av不卡在线播放| 日本av手机在线免费观看| 国产成人a区在线观看| 日产精品乱码卡一卡2卡三| 日日摸夜夜添夜夜爱| 亚洲天堂国产精品一区在线| 亚洲欧洲国产日韩| 简卡轻食公司| 欧美最新免费一区二区三区| 男女边吃奶边做爰视频| 青春草视频在线免费观看| av免费观看日本| 亚洲av免费高清在线观看| 97超碰精品成人国产| 又粗又硬又长又爽又黄的视频 | 真实男女啪啪啪动态图| 国产午夜精品久久久久久一区二区三区| 嫩草影院精品99| 晚上一个人看的免费电影| 天天躁夜夜躁狠狠久久av| 少妇猛男粗大的猛烈进出视频 | 日韩av不卡免费在线播放| 给我免费播放毛片高清在线观看| 不卡视频在线观看欧美| 精品久久久久久久久av| 国产精品蜜桃在线观看 | 亚洲国产欧美人成| 极品教师在线视频| 国产高潮美女av| 日本爱情动作片www.在线观看| 国产av一区在线观看免费| 两性午夜刺激爽爽歪歪视频在线观看| 国产精品久久久久久精品电影| 97热精品久久久久久| 一级毛片aaaaaa免费看小| 亚洲精品久久久久久婷婷小说 | 99热6这里只有精品| 国产在线精品亚洲第一网站| 丰满的人妻完整版| 色尼玛亚洲综合影院| 成人三级黄色视频| 美女 人体艺术 gogo| 天堂中文最新版在线下载 | 69av精品久久久久久| 91精品一卡2卡3卡4卡| 床上黄色一级片| 国产又黄又爽又无遮挡在线| 菩萨蛮人人尽说江南好唐韦庄 | 精品人妻熟女av久视频| 色哟哟哟哟哟哟| 欧美在线一区亚洲| 欧美激情国产日韩精品一区| 美女xxoo啪啪120秒动态图| 亚洲美女搞黄在线观看| 99国产极品粉嫩在线观看| 美女内射精品一级片tv| 国产精品野战在线观看| 精品国产三级普通话版| 麻豆国产av国片精品| 尾随美女入室| 少妇丰满av| 嫩草影院精品99| 国产单亲对白刺激| av.在线天堂| 嫩草影院精品99| 国产91av在线免费观看| 午夜福利在线在线| 亚洲精品影视一区二区三区av| 黄色欧美视频在线观看| 亚洲欧美精品专区久久| 禁无遮挡网站| 美女脱内裤让男人舔精品视频 | 老司机福利观看| 中文欧美无线码| 亚洲人与动物交配视频| 91午夜精品亚洲一区二区三区| 亚洲国产色片| 久久久久久九九精品二区国产| 99久久精品国产国产毛片| av天堂中文字幕网| 六月丁香七月| 国语自产精品视频在线第100页| 日本av手机在线免费观看| 久久久欧美国产精品| 国产精品三级大全| 午夜视频国产福利| 少妇的逼好多水| 亚洲第一电影网av| 免费av毛片视频| 亚洲精品456在线播放app| 久久热精品热| 高清毛片免费观看视频网站| 日韩在线高清观看一区二区三区| 99在线人妻在线中文字幕| 国产乱人偷精品视频| 成人三级黄色视频| 国产真实乱freesex| 99久久久亚洲精品蜜臀av| 免费搜索国产男女视频| 国产老妇女一区| 成人午夜高清在线视频| 麻豆成人av视频| 国产一区二区激情短视频| 免费看日本二区| www日本黄色视频网| 久久人人爽人人片av| 日本-黄色视频高清免费观看| 亚洲av第一区精品v没综合| 国产午夜精品论理片| 国产一区二区在线av高清观看| 国产乱人偷精品视频| 97人妻精品一区二区三区麻豆| 国产v大片淫在线免费观看| 国内揄拍国产精品人妻在线| 成人亚洲精品av一区二区| 国产三级在线视频| 日韩高清综合在线| 我的老师免费观看完整版| 日韩欧美精品免费久久| 白带黄色成豆腐渣| 国产成人精品一,二区 | 亚洲国产精品成人久久小说 | 丰满乱子伦码专区| 又黄又爽又刺激的免费视频.| 菩萨蛮人人尽说江南好唐韦庄 | 国产av不卡久久| 亚洲av熟女| 亚洲人成网站在线观看播放| 日韩欧美三级三区| 中文字幕人妻熟人妻熟丝袜美| 看非洲黑人一级黄片| 51国产日韩欧美| 国产成人精品婷婷| 亚洲中文字幕日韩| 免费电影在线观看免费观看| 99久久精品国产国产毛片| 中文字幕久久专区| 色哟哟哟哟哟哟| a级毛片免费高清观看在线播放| 久久午夜福利片| 欧美成人免费av一区二区三区| 国产极品精品免费视频能看的| 日韩强制内射视频| 成熟少妇高潮喷水视频| 成年女人看的毛片在线观看| 18禁在线无遮挡免费观看视频| 国产成人一区二区在线| 少妇的逼好多水| 国产日韩欧美在线精品| 免费av毛片视频| 国产精品久久久久久久久免| 男女啪啪激烈高潮av片| 久久午夜亚洲精品久久| 国产亚洲精品久久久久久毛片| 亚洲aⅴ乱码一区二区在线播放| 国产精品99久久久久久久久| 精品久久国产蜜桃| 国产在视频线在精品| 久久精品久久久久久噜噜老黄 | 乱人视频在线观看| 成人一区二区视频在线观看| 在线免费观看的www视频| 在线播放国产精品三级| 久久精品夜夜夜夜夜久久蜜豆| 欧美成人精品欧美一级黄| 亚洲精品自拍成人| 久久精品国产99精品国产亚洲性色| 亚洲av中文av极速乱| 人妻少妇偷人精品九色| 国产免费一级a男人的天堂| 99久久无色码亚洲精品果冻| 亚洲在久久综合| 精品久久国产蜜桃| 99热精品在线国产| 长腿黑丝高跟| 日本一本二区三区精品| 少妇人妻一区二区三区视频| 级片在线观看| 日韩欧美一区二区三区在线观看| 高清在线视频一区二区三区 | 女同久久另类99精品国产91| 99久久无色码亚洲精品果冻| 两个人的视频大全免费| 亚洲人与动物交配视频| 日韩精品青青久久久久久| 麻豆成人午夜福利视频| 国产午夜福利久久久久久| 国产成人影院久久av| 精品国内亚洲2022精品成人| 色综合站精品国产| 欧美变态另类bdsm刘玥| 国产黄a三级三级三级人| 欧美人与善性xxx| 观看美女的网站| 国产成人一区二区在线| 18禁在线播放成人免费| 亚洲成人av在线免费| 欧美成人一区二区免费高清观看| 美女脱内裤让男人舔精品视频 | 免费看av在线观看网站| 久久99蜜桃精品久久| 人妻系列 视频| av在线蜜桃| 国产美女午夜福利| 2022亚洲国产成人精品| 色视频www国产| 搡女人真爽免费视频火全软件| 在线播放国产精品三级| 国产精品,欧美在线| 最近最新中文字幕大全电影3| 亚洲美女视频黄频| 精品日产1卡2卡| 久久精品夜夜夜夜夜久久蜜豆| 亚洲美女搞黄在线观看| 99热网站在线观看| 可以在线观看毛片的网站| 亚洲最大成人av| 欧美日韩国产亚洲二区| 18禁在线播放成人免费| 亚洲成av人片在线播放无| 亚洲精品久久国产高清桃花| 免费观看在线日韩| 午夜精品在线福利| 不卡一级毛片| 国产一级毛片在线| 国内揄拍国产精品人妻在线| 又爽又黄a免费视频| 丰满的人妻完整版| 中国美白少妇内射xxxbb| 午夜亚洲福利在线播放| 亚洲成av人片在线播放无| 国产成人影院久久av| 亚洲中文字幕一区二区三区有码在线看| 国产亚洲av嫩草精品影院| 网址你懂的国产日韩在线| 日本欧美国产在线视频| 亚洲成人久久性| 国产精品久久久久久av不卡| 亚洲精品乱码久久久久久按摩| 国产亚洲欧美98| www日本黄色视频网| 欧美色欧美亚洲另类二区| 国产精品国产三级国产av玫瑰| 高清在线视频一区二区三区 | 日韩精品青青久久久久久| 日韩 亚洲 欧美在线| 日韩欧美一区二区三区在线观看| 观看免费一级毛片| 亚洲五月天丁香| 欧美三级亚洲精品| 亚洲国产色片| 亚洲一区二区三区色噜噜| 亚洲av不卡在线观看| 国产成人精品婷婷| av在线蜜桃| 最近视频中文字幕2019在线8| 三级经典国产精品| 麻豆精品久久久久久蜜桃| 深夜精品福利| 国产精品国产高清国产av| 欧美xxxx性猛交bbbb| 高清日韩中文字幕在线| 精品少妇黑人巨大在线播放 | 亚洲国产精品国产精品| 深爱激情五月婷婷| 我的老师免费观看完整版| 高清毛片免费看| 国产一区二区三区在线臀色熟女| 免费观看在线日韩| 一卡2卡三卡四卡精品乱码亚洲| 亚洲精品国产成人久久av| 亚洲中文字幕日韩| 女的被弄到高潮叫床怎么办| 久久久久久国产a免费观看| 小说图片视频综合网站| 国产精品伦人一区二区| 国产av不卡久久| 欧美最新免费一区二区三区| 成年免费大片在线观看| 精品午夜福利在线看| 色综合色国产| 人妻系列 视频| 国产亚洲91精品色在线| .国产精品久久| 成年免费大片在线观看| 少妇的逼好多水| 欧美日韩综合久久久久久| 久久草成人影院| 久久久精品94久久精品| av.在线天堂| 国产精品久久电影中文字幕| 国产精品精品国产色婷婷| 1000部很黄的大片| 在线播放国产精品三级| 亚洲av第一区精品v没综合| 欧美+亚洲+日韩+国产| 亚洲av成人精品一区久久|