HPV对生殖系统影响的研究进展

人乳头瘤病毒（HPV）感染可引发生殖系统的疣变以及恶性肿瘤.其中高危型HPV的感染导致了约70%的女性宫颈癌.HPV病毒蛋白可通过调节细胞基因组的稳定性、转录活性、泛素化途径和细胞代谢等机制诱发癌症.同时HPV的持续慢性感染和免疫应答的紊乱也与宫颈癌的发生相关.本文对HPV感染对生殖系统健康的影响、HPV病毒分子结构、HPV病毒蛋白的致癌的机制以及宿主对于HPV感染的免疫应答的近期研究进展进行了综述,并总结展望了HPV相关生殖系统疾病的预防和治疗的前景.     

Molecular events in uterine cervical cancer

OBJECTIVE: To review the literature regarding the molecular events which occur in the development of uterine cervical cancer, with particular reference to human papillomavirus (HPV) infection. METHODOLOGY: Bibliographic searches of Medline and the ISI citation databases using appropriate keywords, including the following: papillomavirus, cervix, pathology, cyclin, chromosome, heterozygosity, telomerase, smoking, hormones, HLA, immune response, HIV, HSV, EBV. CONCLUSIONS: It has become clear that most cervical neoplasia, whether intraepithelial or invasive, is attributable in part to HPV infection. However, HPV infection alone is not sufficient, and, in a small proportion of cases, may not be necessary for malignant transformation. There is increasing evidence that HPV gene products interfere with cell cycle control leading to secondary accumulation of small and large scale genetic abnormalities. This may explain the association of viral persistence with lesion progression but, in many patients, secondary factors, such as smoking and immune response, are clearly important. However, the mechanisms involved in the interaction between HPV and host factors are poorly understood.


     

Tissue effects of and host response to human papillomavirus infection.

Human papillomaviruses are a heterogeneous group of DNA tumor viruses associated with hyperplastic (warts, condylomata), dysplastic (CIN and VIN), and malignant lesions (carcinomas) of squamous epithelium. Each HPV type is preferentially associated with specific clinical lesions and has an anatomic site preference for either cutaneous or mucosal squamous epithelium. Infection appears to begin in the basal cells. Early gene expression is associated with acanthosis, and late gene expression is associated with appearance of structural antigens and virions in nuclei of cells of the granular layer, usually koilocytotic cells. Malignant transformation of warts and papillomas appears to be related to a variety of factors: (1) infection by certain HPV types (HPV-5, HPV-8, HPV-16, HPV-18, HPV-31); (2) decreased cellular immunity to HPV-associated antigens; and (3) interaction with cofactors such as other microorganisms or sunlight. Spontaneous regression or successful treatment of the benign lesions appears to depend on either naturally acquired or iatrogenically related stimulation of HPV type-specific immunity. The humoral antibody response to HPV particles may be important in preventing infection. In contrast, the local events surrounding regression of warts and condylomata are primarily associated with specific cell-mediated immunity. Local cell-mediated immune responses, particularly cell-associated soluble mediators and stationary macrophage-like cells, may be especially important in the host's immune response to mucosal infections.     

The role of dendritic cells during infection

The skin and the mucosa of the respiratory and gastrointestinal tracts are continuously exposed to microorganisms, but only a limited number of these enter the body and cause disease. To resist microbial infection, the host has developed a multitude of defense mechanisms involving the innate and adaptive immune systems. Dendritic cells (DCs) provide the link between these arms of the immune system. The initiation of an immune response is critically dependent on the activation of DCs, which can discriminate between different classes of microorganisms and elicit tailored antimicrobial immune responses. They have an extraordinary capacity to stimulate naive T cells and initiate primary immune responses. In turn, some pathogens interfere with DC function to block or delay their elimination by the host. Progress in understanding the role of DCs in the host response to microbes is reviewed.     

Cell-mediated immunity during syphilis. A review

Evidence is presented which reinforces the complexity of the host-parasite interaction during the course of syphilis. Infection with Treponema pallidum evokes a complicated antibody response and an assortment of cell-mediated immune reactions in the host. It appears that humoral immunity plays a minor role towards the complete elimination of syphilitic infection while the cellular limb of the immune response may be an important host defence mechanism. Information now available indicates that a state of anergy, or immunosuppression, exists in the early stages of human and experimental rabbit syphilis based upon negative skin reactions to T. pallidum antigen(s), the abnormal histological appearance of lymphoid organs, and impaired in vitro lymphocyte reactivity. It is also evident that in the later stages of the disease cellular immunity becomes activated as delayed type skin reactions can normally be elicited in tertiary syphilitics and lymphocyte behaviour in cell culture appears normal. Several mechanisms have been invoked to explain the delay in an effective immune response against syphilitic infection and the duration of the disease: (1) a capsule-like substance on the outer surface of virulant T. pallidum may act as a barrier against treponemicidal antibody; (2) this material and other biological properties of virulent treponemes could enable spirochaetes to escape being engulfed by macrophages and other phagocytic cells; (3) antigenic competition among different treponemal antigens causing partial tolerance; (4) T. pallidum infection may bring about the elaboration of immunosuppressive substances of host or treponemal origin which inhibit the proper function of lymphocytes, macrophages, and other cell types.     

The oncogenic potential of human papillomaviruses: a review on the role of host genetics and environmental cofactors

Human papillomaviruses (HPVs), with over 100 genotypes, are a very complex group of human pathogenic viruses. In most cases, HPV infection results in benign epithelial proliferations (verrucae). However, oncogenic types of HPV may induce malignant transformation in the presence of cofactors. For example, over 99% of all cervical cancers and a majority of vulval, vaginal, anal and penile cancers are the result of oncogenic HPV types. Such HPV types have been increasingly linked to other epithelial cancers involving the skin, larynx and oesophagus. Although viral infection is necessary for neoplastic transformation, evidence suggests that host and environmental cofactors are also required. Research investigating HPV oncogenesis is complex and quite extensive. The inability to produce mature HPV virions in animal models has been a major limitation in fully elucidating the oncogenic potential and role of associated cofactors in promoting malignant transformation in HPV-infected cells. We have reviewed the literature and provide a brief account of the current understanding of HPV oncogenesis, emphasizing the role of genetic susceptibility, immune response, and environmental and infectious cofactors.     

Human papillomavirus molecular biology and pathogenesis

Human papillomavirus (HPV) infection is the most common sexually transmitted disease in the world and accounts for an estimated 11% of the global cancer incidence in women. HPV-16 is the most prevalent type detected in cervical cancer and along with types 18, 31, 33 and 45 has been classified as a class I carcinogen. In addition to cervical cancer, HPVs are also associated with the malignant transformation of other mucosal and skin cancers. Thus, the combination of the malignant potential of HPV and its high prevalence of infection confers to it an importance of generalized clinical and virological significance. The natural history of HPV infection with or without treatment varies from spontaneous regression to persistence. The most important mechanism for wart regression appears to be cell-mediated immunity. Cytokines released by keratinocytes or cells of the immune system may play a part in the induction of an effective immune response against HPV infection and the subsequent regression of lesions. This review discusses the molecular biology, pathogenesis and immunology of HPV infections.     

Toll-like receptors: applications to dermatologic disease

Toll-like receptors are a recently identified group of receptors that are an important component of the immune system. Thus far, ten different receptors have been identified and have unique tissue distribution, ligand binding properties, cellular signaling pathways, and cytokine production profiles. Importantly, ligand binding has been shown to regulate both the adaptive and host immune response; thus, defects in this pathway have the potential to lead to increased susceptibility to infection and inflammatory dysregulation. In this article, the burgeoning literature pertinent to the discovery and signaling mechanisms are reviewed in addition to the discussion of the important role Toll-like receptors may play in the pathogenesis of numerous skin diseases. LEARNING OBJECTIVE: At the completion of this learning activity, participants should be familiar with the role of Toll-like receptors in host defenses and their relevance to dermatologic diseases.     

A placebo controlled observer blind immunocytochemical and histologic study of epithelium adjacent to anogenital warts in patients treated with systemic interferon alpha in combination with cryotherapy or cryotherapy alone.

OBJECTIVE--To examine biopsy specimens of tissue immediately adjacent to anogenital (AG) warts which had been treated with either cryotherapy plus subcutaneous interferon (IFN) alpha 2a or cryotherapy alone, for histological features of (a) human papilloma virus (HPV) infection (b) localised cellular immune responses, to further characterise any cellular immune infiltrates with tissue immunocytochemistry, and to relate any histological, immunocytochemical findings to the treatment response of nearby AG warts. DESIGN--A randomised placebo controlled observer blind study. SETTING--Genitourinary Medicine clinic, Department of Immunopathology, Royal Victoria Hospital, Belfast, N. Ireland. SUBJECTS--Thirty patients with AG warts; 16 treated with IFN alpha 2a plus cryotherapy, and 14 treated with cryotherapy alone. OUTCOME MEASURES--(1) Light microscopic features associated with HPV infection and local cellular immune responses. (2) Indirect immunofluorescence detection of the following cell surface markers: HLA DR, alpha one antitrypsin, CD1, CD3, CD4, CD8, CD22. (3) Clinical response of AG warts to treatment. RESULTS--In pre-treatment biopsies only non specific indicators of HPV infection (acanthosis, 29/30 biopsies, and hyperkeratosis, 7/30 biopsies) were seen on light microscopy. Mononuclear cells were seen both throughout the upper dermis and centred around dermal blood vessels in 19/30 (63.3%) biopsies, and infiltrating into the epidermis in 12/30 (40%) biopsies. On indirect immunofluorescence CD3, CD8, CD4 antigen was detected on the surface of cells throughout the upper dermis in 24/29 (82.7%), 15/29 (51.7%), and 3/29 (10.3%), of biopsy specimens respectively. CD3 antigen, CD8 antigen and CD4 antigen was detected on the surface of cells infiltrating into the epidermis in 18/29 (62%), 7/29 (24.1%), and 6/29 (20.7%) of biopsy specimens respectively. CD1 antigen was seen on the surface of dendritic cells throughout the epidermis in all specimens; CD1 positive cells infiltrated into the upper dermis in 5/29 (17.2%). HLA DR was detected on the surface of dendritic cells throughout the epidermis in 22/29 (75.9%) of specimens, and on the surface of cells scattered both diffusely throughout the upper dermis and centred around dermal blood vessels in all specimens. Alpha one antitrypsin (A1AT) antigen was seen on the surface of cells in the upper dermis in 6/29 (20.7%) of biopsy specimens; no cells expressing CD22 surface antigen were seen. The nature of this local cellular immune response was not altered by treatment of nearby warts with either cryotherapy alone or cryotherapy plus systemic IFN alpha 2a, or related to the therapeutic outcome of these warts. CONCLUSIONS--(1) No convincing histological evidence of HPV infection was seen in epithelium surrounding AG warts. (2) A predominantly T cell-mediated immune response (the target of which is uncertain) was seen in this perilesional epithelium. (3) In the dosage regimens used in this study, treatment of AG warts with either systemic IFN alpha 2a plus cryotherapy or cryotherapy alone did not appear to augment localised cellular immune responses (against any presumed subclinical HPV infection) in epithelium surrounding AG warts.     

梅毒免疫和梅毒螺旋体的研究进展

梅毒螺旋体有着独特的基因和蛋白结构,对其基因分型有利于梅毒分子流行病学的研究.梅毒螺旋体缺乏脂多糖与外膜蛋白,但可表达多种脂蛋白,这些脂蛋白同梅毒螺旋体的组织黏附及播散有关,同时可诱导机体发生免疫应答.机体对于梅毒螺旋体的免疫应答过程十分复杂,固有免疫、体液免疫及细胞免疫均在梅毒螺旋体的感染过程中参与了应答过程.Th1型细胞免疫在梅毒的发生发展过程中起重要作用,梅毒患者在局部及系统免疫方面都存在细胞免疫的异常.     

New knowledge regarding herpes zoster

Zoster is the clinical manifestation of the endogenous reactivation of the varicella-zoster virus. Current observations of viral reactivation emphasize the role of cellular immunity and show an inverse correlation between the specific cellular immune response of the host and the incidence of zoster. Thus, immunocompromised persons like patients with immune deficiency syndrome, lymphoproliferative cancer, or immunosuppressive therapy are at a high risk for the development of disseminated zoster, which may either involve the skin only, or affect more than one organ. During the last few years zoster has been proved a prognostic marker for HIV-positive persons. The incidence of zoster and post-zoster neuralgia increases with advancing age. In young children, immunosuppressive therapy and varicella in utero or during the first year of life are the only risk factors for zoster infection. Prevention of dissemination has been one of the major goals in antiviral chemotherapy of zoster in immunocompromised patients. Among the antiviral drugs available at present, aciclovir has proved especially useful, acting as an inhibitor of viral DNA polymerase. It is well-tolerated and can be applied together with corticoids, analgetics, and retrovir. It is most effective in reducing complications of zoster.     

Control of cutaneous antimicrobial peptides by vitamin D3

Constant exposure to a wide variety of microbial pathogens represents a major challenge for our skin. Antimicrobial peptides (AMPs) are mediators of cutaneous innate immunity and protect primarily against microbial infections. Cathelicidins were among the first AMPs identified in human skin and recent evidence suggests that they exert a dual role in innate immune defense: At first, due to their antimicrobial activity they kill pathogens directly. In addition, these peptides initiate a potent host response to infection resulting in cytokine release, inflammation and a cellular response. Disturbed cathelicidin expression and function was observed in several common inflammatory skin diseases, such as psoriasis where cathelicidin peptide converts inert self-DNA and self-RNA into an autoimmune stimulus. In atopic dermatitis decreased levels of cathelicidin facilitating microbial superinfections have been discussed. Furthermore, abnormally processed cathelicidin peptides induce inflammation and a vascular response in rosacea. Until recently, the molecular mechanisms underlying cathelicidin regulation were unknown. Recently, the vitamin D3 pathway was identified as the major regulator of cathelicidin expression. Consequently, vitamin D3 entered the spotlight as an immune modulator with impact on both innate and adaptive immunity. Therapies targeting vitamin D3 signaling may provide new approaches for infectious and inflammatory skin diseases by affecting both innate and adaptive immune functions.     

Human papillomavirus-related genital disease in the immunocompromised host: Part I

Human papillomavirus (HPV) is responsible for common condyloma acuminata and a number of premalignant and malignant anogenital lesions. These conditions are of particular concern in immunocompromised individuals who have higher risk of malignant transformation and are more difficult to treat. This is part I of a two-part review that will highlight the cutaneous features of condyloma acuminata and vaginal, vulvar, penile, and anal intraepithelial neoplasias, with an emphasis on presentation of these HPV-mediated diseases in the immunocompromised host. Counseling patients about these conditions requires a thorough understanding of the epidemiology, natural history of HPV, transmission and infectivity, risk of malignancy, and the role of the host immune response in clearing HPV lesions. Part II will provide an updated review of available treatments, with a focus on recent advances and the challenges faced in successfully treating HPV lesions in immunocompromised patients.     

梅毒免疫学机制研究进展

在梅毒螺旋体感染的不同病期,细胞免疫和体液免疫均有部分涉及,目前认为主要与T细胞介导的免疫反应有关,血清抗体仅有部分保护作用,同时还存在不同程度的免疫抑制现象。梅毒早期出现的体液免疫和细胞免疫对梅毒螺旋体的清除起重要作用,而在晚期出现的细胞免疫反应则主要引起组织损害。本文就近年来关于梅毒螺旋体的免疫原性、感染梅毒后机体的免疫反应以及梅毒螺旋体免疫逃逸等方面的研究进展作一综述。     

白介素-12家族在分枝杆菌感染中作用的研究进展

白介素-12已被认为是诱导Th1免疫反应产生和维持的重要细胞因子,其中以其亚基白介素-12／23p40的研究尤为多见。研究显示,该亚基在抵抗细菌尤其是分枝杆菌感染中可能发挥作用,可形成单体或同源二聚体,通过与细胞表面的白介素-12受体B1竞争性结合发挥作用。致病力强的分枝杆菌可通过降低白介素-12p70的生成来抵抗宿主的免疫反应从而达到自我防御的目的。在白介素-12正常存在的情况下,白介素-23在控制分枝杆菌感染过程中的作用有限,但其可通过诱导Th17细胞及记忆性T淋巴细胞在慢性结核杆菌感染中发挥保护作用。白介素-27作为第3个白介素-12家族成员,在分枝杆菌感染后的机体免疫反应中的作用存在争议,对于不同的细胞群体如巨噬细胞、淋巴细胞等作用可能不同甚至相反。     

Possibilities of immunotherapy in malignant melanoma]

The immune response of malignant melanoma bases on evident humoral and cellular defence mechanisms of the host against his tumor. Of special interest is a defective immune response, developing in the course of the disease. Hence, any immunotherapy aims at an immunostimulation and immunoregulation. Local and systemic nonspecific immunotherapy try to raise an immune response against the tumor by stimulating unspecifically the whole immune system. On the contrary, specific immunotherapy tries to stimulate directly the defence mechanisms against the tumor by transfusion of antisera (passive immunotherapy) and sensitized cells (adoptive immunotherapy) and by immunizing the patient with tumor tissue (active immunotherapy). One of the best ways in therapy of melanoma seems to be the combination of immunotherapy with chemotherapy, as yet employed in BCG and DTIC treatment.     

HPV16 activates the AIM2 inflammasome in keratinocytes

Human papillomaviruses (HPV) are double-stranded DNA viruses, which selectively infect keratinocytes in stratified epithelia. After an initial infection, many patients clear HPV. In some patients, however, HPV persist, and dysfunctional innate immune responses to HPV infection could be involved in the ineffective clearing of these viruses. In this study, the mechanisms of HPV-induced immune responses in keratinocytes were investigated. Binding of viral DNA leads to AIM2 inflammasome activation and IL-1β release, while IFI16 activation results in IFN-β release. Using immunohistochemistry, AIM2 and IFI16—two recently identified sensors for cytosolic DNA—were also detected in HPV positive skin lesions. CISH stainings further confirmed the presence of cytosolic HPV16 DNA in biopsy samples. Moreover, active IL-1β and cleaved caspase-1 were detected in HPV infected skin, suggesting inflammasome activation by viral DNA. In subsequent functional studies, HPV16 DNA triggered IL-1β and IL-18 release via the AIM2 inflammasome in normal human keratinocytes. Although HPV DNA did not induce IFN-β in keratinocytes, IFN-β secretion was observed when AIM2 was blocked. Meanwhile, blocking of IFI16 increased HPV16 DNA-induced IL-1β, but not IL-18, secretion. These findings suggest crosstalk between IFI16 and AIM2 in the immune response to HPV DNA. In sum, novel aspects concerning HPV-induced innate immune responses were identified. Eventually, understanding the mechanisms of HPV-induced inflammasome activation could lead to the development of novel strategies for the prevention and treatment of HPV infections.     

The role of human papillomavirus in common skin conditions: current viewpoints and therapeutic options

A direct causal relationship between human papillomavirus (HPV) infection and cervical neoplasia is well-accepted, but the specific role of HPV in the pathogenesis of other cutaneous disorders is less clear. This article explores the role of HPV in 2 common disorders associated with considerable morbidity: external genital and perianal warts (EGWs) and actinic keratosis (AK). Because the potential role of HPV in the pathogenesis of EGW and AK may have implications that influence management, the available topical pharmacotherapy for each disorder also is reviewed. External genital and perianal warts represent a possible phenotypic expression of HPV infection and results from hyperkeratosis and hyperplasia of keratinocytes. The cell cycle disruption caused by low-risk anogenital HPV subtypes (eg, HPV-6, HPV-11) is similar to high-risk HPV subtypes, except low-risk HPV E6 and E7 proteins likely bind regulatory proteins with less affinity. Although UV light clearly has a primary causal role in the development of AK, new data suggest that HPV infection, particularly with 3-HPV subtypes, may serve as a cocarcinogen. By impairing normal DNA repair and apoptotic mechanisms, HPV may set the stage for later UV-induced transformation. It also has been suggested that HPV may increase the severity of AK lesions and contribute to their recurrence following therapy.     

Cross-sectional associations between cutaneous viral infections and regulatory T lymphocytes in circulation

Approximately three million non-melanoma skin cancers (NMSCs) are diagnosed worldwide each year, although this number is likely an underestimate given that these cancers are not always recorded in cancer registries. Studies have suggested that skin (cutaneous) infections with human papillomaviruses (HPV) and polyomaviruses (HPyV) may play a role in the development of some NMSC types. Suppression of the immune system is also a risk factor for NMSC. This study, from the U.S.A, aimed to understand the relationship between T-regulatory (Treg) cells, cells which suppress immune response, and cutaneous viral infections. Blood, skin swabs and eyebrow hairs were collected from 352 patients who underwent skin cancer screening and did not have cancer detected. The researchers examined whether the skin swabs (SSW) and eyebrow hairs (EBH) contained genetic material (DNA) corresponding to 98 cutaneous HPV types (including beta HPV and gamma HPV) and 5 HPyV types. The blood samples were analyzed to determine proportions of different types of Treg cell populations in circulation (in the blood). The researchers found no association between total percent of circulating Treg cells and beta HPV or HPyV infection. However, two types of Treg cells were found at lower levels in those that had gamma HPV infection in their EBH and/or SSW. Those two types were CLA⁺ Treg cells (known to travel to the skin) and effector CD27^-CD45RA^-FOXP3⁺CD4⁺ Treg cells (known to become active when exposed to a foreign viral infection). The study results suggest that gamma HPV infection may stimulate Treg cells to move from circulation into the skin tissues.