Production of Polyclonal Antibody to the HPV58 E7 Protein and Its Detection in Cervical Cancer

An Overview of the Mechanisms Against "Candidatus Liberibacter asiaticus": Virulence Targets, Citrus Defenses, and Microbiome

Citrus Huanglongbing (HLB) or citrus greening, is the most destructive disease for citrus worldwide. It is caused by the psyllid-transmitted, phloem-limited bacteria "Candidatus Liberibacter asiaticus" (CLas). To date, there are still no effective practical strategies for curing citrus HLB. Understanding the mechanisms against CLas can contribute to the development of effective approaches for combatting HLB. However, the unculturable nature of CLas has hindered elucidating mechanisms against CLas. In this review, we summarize the main aspects that contribute to the understanding about the mechanisms against CLas, including (1) CLas virulence targets, focusing on inhibition of virulence genes; (2) activation of citrus host defense genes and metabolites of HLB-tolerant citrus triggered by CLas, and by agents; and (3) we also review the role of citrus microbiome in combatting CLas. Finally, we discuss novel strategies to continue studying mechanisms against CLas and the relationship of above aspects.

Immunohistochemical Detection of Human Papillomavirus 16 E7 Oncoprotein in Cervical Lesions

Almost all cervical cancer is associated with persistent infection of high-risk (hr) human papillomavirus (HPV) like HPV16. The E7 oncoprotein encoded by hrHPV plays a crucial role in carcinogenesis. The present study aimed to establish a reliable protocol of immunohistochemistry stains to detect HPV16 E7 protein in formalin-fixed and paraffin-embedded tissue specimens of various cervical lesions. Firstly, the HPV16 E7 gene was inserted into a prokaryotic expression vector pGEX-4T2. Then the recombinant plasmid pGEX-4T2-(HPV16-E7) was transformed into Escherichia coli JM109. The fusion protein containing a GST tag was purified, and New Zealand white rabbits were immunized to produce the HPV16 E7 polyclonal antibody. The anti-HPV16 E7 antibody was verified by western blotting and immunofluorescence stains, and applied in 182 HPV16 DNA-positive cervical tissue specimens and matched 36 HPV DNA-negative specimens by immunohistochemistry. Furthermore, A positive correlation between HPV16 E7 protein expression and malignancy grade was observed. But there is no relationship between HPV16 E7 protein expression and tumor sizes, tumor differentiation, lymph node metastasis, International Federation of Gynecology and Obstetrics (FIGO) stage, or lymphovascular space invasion in cervical cancer. These findings provide a basis for further research focusing on the role of HPV E7 protein in various HPV-related diseases.

HPV58 E7 Protein Expression Profile in Cervical Cancer and CIN with Immunohistochemistry

Background: The persistent infection of high-risk human papillomavirus (HR-HPV) is one of the most common causes of cervical cancer worldwide, and HPV type 58 (HPV58) is the third most common HPV type in eastern Asia. The E7 oncoprotein is constitutively expressed in HPV58-associated cervical cancer cells and plays a key role during tumorigenesis. This study aimed to assess the HPV58 E7 protein expression in the tissues of cervical cancer and cervical intraepithelial neoplasia (CIN).

Methods: A total of 67 HPV58-positive cervical samples were collected, including 25 cervical cancer samples and 42 CIN samples. All the tissues were examined by HPV58 E7, p16^INK4a and Ki67 immunohistochemistry (IHC). At last, we analyzed their association with clinical and pathological variables.

Results: HPV58 E7 expression was detected in 96% of the HPV58 DNA-positive cervical cancer tissues and 85.7% of HPV58-positive CIN tissues. 65 samples of cervical cancer and CIN tissues had p16-positive staining, while 59 samples were Ki-67 positive.

Conclusions: HPV58 E7 protein is highly expressed in both cervical cancer and CIN tissues. HPV58 E7 IHC could be sensitive and specific for evaluating HPV-driven cervical cancer and pre-cancerous lesions, in combination with p16 and Ki-67 IHC.

Immunodiagnosis and Immunotherapeutics Based on Human Papillomavirus for HPV-Induced Cancers

Infection with human papillomavirus (HPV) is one of the main causes of malignant neoplasms, especially cervical, anogenital, and oropharyngeal cancers. Although we have developed preventive vaccines that can protect from HPV infection, there are still many new cases of HPV-related cancers worldwide. Early diagnosis and therapy are therefore important for the treatment of these diseases. As HPVs are the major contributors to these cancers, it is reasonable to develop reagents, kits, or devices to detect and eliminate HPVs for early diagnosis and therapeutics. Immunological methods are precise strategies that are promising for the accurate detection and blockade of HPVs. During the last decades, the mechanism of how HPVs induce neoplasms has been extensively elucidated, and several oncogenic HPV early proteins, including E5, E6, and E7, have been shown to be positively related to the oncogenesis and malignancy of HPV-induced cancers. These oncoproteins are promising biomarkers for diagnosis and as targets for the therapeutics of HPV-related cancers. Importantly, many specific monoclonal antibodies (mAbs), or newly designed antibody mimics, as well as new immunological kits, devices, and reagents have been developed for both the immunodiagnosis and immunotherapeutics of HPV-induced cancers. In the current review, we summarize the research progress in the immunodiagnosis and immunotherapeutics based on HPV for HPV-induced cancers. In particular, we depict the most promising serological methods for the detection of HPV infection and several therapeutical immunotherapeutics based on HPV, using immunological tools, including native mAbs, radio-labelled mAbs, affitoxins (affibody-linked toxins), intracellular single-chain antibodies (scFvs), nanobodies, therapeutical vaccines, and T-cell-based therapies. Our review aims to provide new clues for researchers to develop novel strategies and methods for the diagnosis and treatment of HPV-induced tumors.

Digital RNA Sequencing of Human Epidermal Keratinocytes Carrying Human Papillomavirus Type 16 E7

High-risk human papillomavirus (HPV) infections are the predominant cause of cervical cancer and its early gene E7 plays an important role in cellular proliferation and cell-cycle progression. While tremendous progress has been made in exploring the molecular mechanisms in late tumorigenesis, many pathways showing how HPV deregulates host gene expression in early inapparent infections and early tumorigenesis still remain undefined. Digital RNA sequencing was performed and a total of 195 differentially expressed genes were identified between the HPV16 E7-transfected NHEKs and control cells (p < 0.05, fold-change > 2). GO enrichment showed that HPV16 E7 primarily affected processes involved in anti-viral and immune responses, while KEGG pathway analysis showed enrichment of gene clusters of associated with HPV infection and MAPK signaling. Of the differentially expressed genes, IFI6, SLC39A9 and ZNF185 showed a strong correlation with tumor progression and patient survival in the OncoLnc database while roles for AKAP12 and DUSP5 in carcinogenesis and poor prognosis have previously been established for other cancer types. Our study identified several novel HPV16 E7-regulated candidate genes with putative functions in tumorigenesis, thus providing new insights into HPV persistence in keratinocytes and early onset of tumorigenesis.

Production of antibody against elephant endotheliotropic herpesvirus (EEHV) unveils tissue tropisms and routes of viral transmission in EEHV-infected Asian elephants

Elephant endotheliotropic herpesvirus (EEHV) is one of the most devastating viral infectious diseases in elephants worldwide. To date, it remains unclear how elephants get infected by the virus, where the virus persists, and what mechanisms drive the pathogenesis of the disease. The present study was aimed to develop an antibody against glycoprotein B (gB) of EEHV, investigate the EEHV tissue tropisms, and provide the possible routes of EEHV transmission in Asian elephants. Samples from elephant organs that had died from EEHV1A and EEHV4 infections, peripheral blood mononuclear cells (PBMC) from EEHV4- and non-EEHV-infected calves were used in this study. The results of western immunoblotting indicated that the antibody can be used for detection of gB antigens in both EEHV1A- and EEHV4-infected samples. Immunohistochemical detection indicated that the EEHV gB antigens were distributed mainly in the epithelial cells of the salivary glands, stomach and intestines. Immunofluorescence test of PBMC for EEHV gB in the EEHV4-infected calf indicated that the virus was observed predominantly in the mononuclear phagocytic cells. The findings in the present study unveil tissue tropisms in the EEHV1A- and EEHV4-infected calves and point out that saliva and intestinal content are likely sources for virus transmission in EEHV-infected Asian elephants.