The Use of Recombinant Pseudotype Virus-Like Particles Harbouring Inserted Target Antigen to Generate Antibodies against Cellular Marker p16INK4A

Protein engineering provides an opportunity to generate new immunogens with desired features. Previously, we have demonstrated that hamster polyomavirus major capsid protein VP1-derived virus-like particles (VLPs) are highly immunogenic and can be employed for the insertion of foreign epitopes at certain surface-exposed positions. In the current study, we have designed pseudotype VLPs consisting of an intact VP1 protein and VP2 protein fused with the target antigen—cellular marker p16INK4A—at its N terminus. Both proteins coexpressed in yeast were self-assembled to pseudotype VLPs harbouring the inserted antigen on the surface. The pseudotype VLPs were used for generation of antibodies against p16INK4A that represents a potential biomarker for cells transformed by high-risk human papillomavirus (HPV). The pseudotype VLPs induced in immunized mice a strong immune response against the target antigen. The antisera raised against pseudotype VLPs showed specific immunostaining of p16INK4A protein in malignant cervical tissue. Spleen cells of the immunized mice were used to generate monoclonal antibodies against p16INK4A protein. The specificity of antibodies was proven by the immunostaining of HPV-transformed cells. In conclusion, the current study demonstrates the potential of pseudotype VLPs with inserted target antigen as a new type of immunogens to generate antibodies of high diagnostic value

Technical Aspects and Clinical Limitations of Sperm DNA Fragmentation Testing in Male Infertility: A Global Survey, Current Guidelines, and Expert Recommendations

PURPOSE: Sperm DNA fragmentation (SDF) is a functional sperm abnormality that can impact reproductive potential, for which four assays have been described in the recently published sixth edition of the WHO laboratory manual for the examination and processing of human semen. The purpose of this study was to examine the global practices related to the use of SDF assays and investigate the barriers and limitations that clinicians face in incorporating these tests into their practice. MATERIALS AND METHODS: Clinicians managing male infertility were invited to complete an online survey on practices related to SDF diagnostic and treatment approaches. Their responses related to the technical aspects of SDF testing, current professional society guidelines, and the literature were used to generate expert recommendations via the Delphi method. Finally, challenges related to SDF that the clinicians encounter in their daily practice were captured. RESULTS: The survey was completed by 436 reproductive clinicians. Overall, terminal deoxynucleotidyl transferase deoxyuridine triphosphate Nick-End Labeling (TUNEL) is the most commonly used assay chosen by 28.6%, followed by the sperm chromatin structure assay (24.1%), and the sperm chromatin dispersion (19.1%). The choice of the assay was largely influenced by availability (70% of respondents). A threshold of 30% was the most selected cut-off value for elevated SDF by 33.7% of clinicians. Of respondents, 53.6% recommend SDF testing after 3 to 5 days of abstinence. Although 75.3% believe SDF testing can provide an explanation for many unknown causes of infertility, the main limiting factors selected by respondents are a lack of professional society guideline recommendations (62.7%) and an absence of globally accepted references for SDF interpretation (50.3%). CONCLUSIONS: This study represents the largest global survey on the technical aspects of SDF testing as well as the barriers encountered by clinicians. Unified global recommendations regarding clinician implementation and standard laboratory interpretation of SDF testing are crucial

Technical aspects and clinical limitations of sperm DNA fragmentation testing in male infertility: A global survey, current guidelines, and expert recommendations

Purpose Sperm DNA fragmentation (SDF) is a functional sperm abnormality that can impact reproductive potential, for which four assays have been described in the recently published sixth edition of the WHO laboratory manual for the examination and processing of human semen. The purpose of this study was to examine the global practices related to the use of SDF assays and investigate the barriers and limitations that clinicians face in incorporating these tests into their practice. Materials and Methods Clinicians managing male infertility were invited to complete an online survey on practices related to SDF diagnostic and treatment approaches. Their responses related to the technical aspects of SDF testing, current professional society guidelines, and the literature were used to generate expert recommendations via the Delphi method. Finally, challenges related to SDF that the clinicians encounter in their daily practice were captured. Results The survey was completed by 436 reproductive clinicians. Overall, terminal deoxynucleotidyl transferase deoxyuridine triphosphate Nick-End Labeling (TUNEL) is the most commonly used assay chosen by 28.6%, followed by the sperm chromatin structure assay (24.1%), and the sperm chromatin dispersion (19.1%). The choice of the assay was largely influenced by availability (70% of respondents). A threshold of 30% was the most selected cut-off value for elevated SDF by 33.7% of clinicians. Of respondents, 53.6% recommend SDF testing after 3 to 5 days of abstinence. Although 75.3% believe SDF testing can provide an explanation for many unknown causes of infertility, the main limiting factors selected by respondents are a lack of professional society guideline recommendations (62.7%) and an absence of globally accepted references for SDF interpretation (50.3%). Conclusions This study represents the largest global survey on the technical aspects of SDF testing as well as the barriers encountered by clinicians. Unified global recommendations regarding clinician implementation and standard laboratory interpretation of SDF testing are crucial

Integration of human papillomavirus type 16 in cervical cancer cells

Cervical cancer remains an important cause of women morbidity and mortality. The progression of cervical pathology correlates with the HPV integration into the host genome. However, the data on the viral integration status in cervical dysplasias are controversial. The aim of the current study was to evaluate the status of HPV integration in two types of cervical pathology – invasive and non invasive cervical cancer (e.g. carcinoma in situ). 156 women were included in the study: 66 women were diagnosed with invasive cervical cancer (CC) and 90 with non invasive cervical cancer (carcinoma in situ, CIS). 74.2% [95% PI: 63.64÷84.76] of specimens collected from women with diagnosed CC and 85.6% [95% PI: 85.53÷92.85] of CIS specimens were positive for HPV. The most prevalent HPV genotype in both groups was HPV16. To evaluate HPV integration, three selected HPV16 E2 gene fragments were analyzed by PCR. In the majority of CC and CIS specimens the amplification of all three HPV16 E2 gene fragments was observed. The episomal HPV16 form was detected in the majority of CC and CIS specimens. The deletion of all three HPV16 E2 gene fragments was detected in 9.4% of CC specimens and 2.2% of CIS specimens. Finally, integration status could not be used as diagnostical additional test to distinguish between invasive and non invasive cervical cancer