Browsing by Author "Carse, Sinead"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Open Access
    Advances in Targeting HPV Infection as Potential Alternative Prophylactic Means
    (2021-02-23) Carse, Sinead; Bergant, Martina; Schäfer, Georgia
    Infection by oncogenic human papillomavirus (HPV) is the primary cause of cervical cancer and other anogenital cancers. The majority of cervical cancer cases occur in low- and middle- income countries (LMIC). Concurrent infection with Human Immunodeficiency Virus (HIV) further increases the risk of HPV infection and exacerbates disease onset and progression. Highly effective prophylactic vaccines do exist to combat HPV infection with the most common oncogenic types, but the accessibility to these in LMIC is severely limited due to cost, difficulties in accessing the target population, cultural issues, and maintenance of a cold chain. Alternative preventive measures against HPV infection that are more accessible and affordable are therefore also needed to control cervical cancer risk. There are several efforts in identifying such alternative prophylactics which target key molecules involved in early HPV infection events. This review summarizes the current knowledge of the initial steps in HPV infection, from host cell-surface engagement to cellular trafficking of the viral genome before arrival in the nucleus. The key molecules that can be potentially targeted are highlighted, and a discussion on their applicability as alternative preventive means against HPV infection, with a focus on LMIC, is presented.
  • Thumbnail Image
    Item
    Open Access
    Characterisation of human surfactant protein A and recombinant human vimentin in their modulation of HPV16 pseudovirus infection
    (2019) Carse, Sinead; Schafer, Georgia; Katz, Arieh
    Infection by oncogenic human papillomavirus (HPV) is the primary cause of cervical cancer, where low-and middle-income countries (LMIC) have the highest incidence. Prophylactic HPV vaccines exist but LMIC have limited access. Therefore, alternative preventative measures against HPV infection and cervical cancer progression are needed. Two human proteins have been identified in our laboratory that modulate HPV16 pseudovirus (HPV16-PsVs) infection in vitro, namely surfactant protein A (SP-A) and recombinant human vimentin (rhVim). Previous work suggested SP-A mediated immune recognition of HPV since SP-A-coated HPV16- PsVs enhanced viral uptake by RAW264.7 murine macrophages. These initial observations were confirmed using a murine C57BL/6 cervicovaginal challenge model: pre-incubation of HPV16- PsVs with purified human SP-A significantly reduced the level of HPV16-PsV infection in vivo. Moreover, when isolated cells from female reproductive tracts of naïve C57BL/6 mice were incubated with HPV16-PsVs and stained for selected innate immune cell populations by flow cytometry, significant increases in viral uptake by eosinophils, neutrophils, monocytes and macrophages were observed over time using SP-A-pre-coated virions compared to control particles. Compared to SP-A mediated modulation of HPV infection through activation of innate immune responses, rhVim was suggested to directly interfere with HPV entry into host cells. Indeed, supplementation with non-filamentous rhVim resulted in decreased viral uptake by NIKS cells which was confirmed in vivo using the murine C57BL/6 cervicovaginal HPV16-PsVs challenge model. Co-localisation analysis employing confocal imaging, revealed that rhVim-coated HPV16- PsVs co-localised, to a lesser degree, with surface-expressed heparan sulphate proteoglycans (HSPGs) than control particles. Removal of surface HSPGs on NIKS cells decreased HPV16-PsVs cell surface binding and internalisation, while pre-incubation of HPV16-PsVs with rhVim decreased viral particle binding and internalisation to a greater extent. This indicates that rhVim may modulate HPV16 infection by interfering with its attachment to HSPGs as well as viral engagement with the yet unknown entry receptor(s). In summary, both SP-A and vimentin modulate HPV16-PsVs infection by different mechanisms. These in vivo studies strongly confirm previous in vitro observations, rendering both proteins potentially suitable for further development into possible candidates for use in topical microbicides, which may provide protection against new HPV infections.
  • No Thumbnail Available
    Item
    Open Access
    Characterisation of surfactant protein a as a novel prophylactic means against oncogenic HPV infections
    (2024) Carse, Sinead; Schäfer, Georgia
    Infection with Human Papillomavirus (HPV) presents a continuous global health challenge due to its incurable nature, particularly impacting low- and middle-income countries (LMIC). Although highly effective prophylactic vaccines targeting the most prevalent HPV types exist, they do not cover all oncogenic HPV types found in malignant lesions and the extent of cross protection against other oncogenic HPV types is limited. Moreover, these vaccines are ineffective for women already infected with high-risk HPV types. These limitations are more prominent in LMIC, where limited healthcare access, awareness, and proper transport and storage hinder vaccine accessibility. Cervical cancer's persistent status as the fourth most common cancer in women globally underscores the urgent need for alternative interventions that broadly target HPV infections. In an effort to identify alternative broad-spectrum protective means against HPV infection, our previous research identified surfactant protein A (SP-A), an innate immune opsonin, as a novel molecule capable of recognising HPV16 pseudovirions (HPV16-PsVs) with functional consequences for reduced infection in a murine cervicovaginal HPV challenge model. Building on these findings, our aim was to assess SP-A's suitability as a novel broad-spectrum HPV targeting molecule to prevent initial viral infection of the human keratinocyte cell line, HaCaT. Additionally, we aimed to study SP-A's ability to agglutinate HPV-PsVs and to assess potential consequences of this SP-A coating on immune cell recognition and elicited immune responses in human-derived immune cells. Our study demonstrated SP-A's ability to agglutinate and opsonise multiple oncogenic HPV PsVs types, which was accompanied by their enhanced uptake and clearance by RAW264.7 murine macrophages, THP-1 monocytes, and THP-1-derived immature dendritic cells (DC0). Importantly, SP-A-opsonised HPV-PsVs resulted in decreased viral uptake and infection of HaCaT keratinocytes. These results were supported by increased lysosomal accumulation of SP-A-opsonised HPV16-PsVs as observed for both RAW264.7 and HaCaT cells. Co-culturing selected immune cells with HaCaT keratinocytes further reduced HPV-PsV infection in the presence of SP-A which might be explained by SP-A's behaviour in driving a proinflammatory immune response in THP-1 and DC0, in the presence of HPV16-PsVs, as identified by cytokine profiling. These results unveiled SP-A's versatility and substantial influence on various HPV interactions with immune cells and keratinocytes and laid the foundation for future research into the development of alternative prophylactic interventions. Increasing innate immune recognition by exogenous supplementation with SP-A (or SP-A derivatives) holds promise for broader protection against diverse HPV types and potentially other sexually transmitted infections.
  • Thumbnail Image
    Item
    Open Access
    Exogenous Vimentin Supplementation Transiently Affects Early Steps during HPV16 Pseudovirus Infection
    (2021-12-10) Carse, Sinead; Lang, Dirk; Katz, Arieh A; Schäfer, Georgia
    Understanding and modulating the early steps in oncogenic Human Papillomavirus (HPV) infection has great cancer-preventative potential, as this virus is the etiological agent of virtually all cervical cancer cases and is associated with many other anogenital and oropharyngeal cancers. Previous work from our laboratory has identified cell-surface-expressed vimentin as a novel HPV16 pseudovirus (HPV16-PsVs)-binding molecule modulating its infectious potential. To further explore its mode of inhibiting HPV16-PsVs internalisation, we supplemented it with exogenous recombinant human vimentin and show that only the globular form of the molecule (as opposed to the filamentous form) inhibited HPV16-PsVs internalisation in vitro. Further, this inhibitory effect was only transient and not sustained over prolonged incubation times, as demonstrated in vitro and in vivo, possibly due to full-entry molecule engagement by the virions once saturation levels have been reached. The vimentin-mediated delay of HPV16-PsVs internalisation could be narrowed down to affecting multiple steps during the virus’ interaction with the host cell and was found to affect both heparan sulphate proteoglycan (HSPG) binding as well as the subsequent entry receptor complex engagement. Interestingly, decreased pseudovirus internalisation (but not infection) in the presence of vimentin was also demonstrated for oncogenic HPV types 18, 31 and 45. Together, these data demonstrate the potential of vimentin as a modulator of HPV infection which can be used as a tool to study early mechanisms in infectious internalisation. However, further refinement is needed with regard to vimentin’s stabilisation and formulation before its development as an alternative prophylactic means.