Progress in L2-Based Prophylactic Vaccine Development for Protection against Diverse Human Papillomavirus Genotypes and Associated Diseases

The human papillomaviruses (HPVs) are a family of small DNA tumor viruses including over 200 genotypes classified by phylogeny into several genera. Different genera of HPVs cause ano-genital and oropharyngeal cancers, skin cancers, as well as benign diseases including skin and genital warts. Licensed vaccines composed of L1 virus-like particles (VLPs) confer protection generally restricted to the ≤9 HPV types targeted. Here, we examine approaches aimed at broadening the protection against diverse HPV types by targeting conserved epitopes of the minor capsid protein, L2. Compared to L1 VLP, L2 is less immunogenic. However, with appropriate presentation to the immune system, L2 can elicit durable, broadly cross-neutralizing antibody responses and protection against skin and genital challenge with diverse HPV types. Such approaches to enhance the strength and breadth of the humoral response include the display of L2 peptides on VLPs or viral capsids, bacteria, thioredoxin and other platforms for multimerization. Neither L2 nor L1 vaccinations elicit a therapeutic response. However, fusion of L2 with early viral antigens has the potential to elicit both prophylactic and therapeutic immunity. This review of cross-protective HPV vaccines based on L2 is timely as several candidates have recently entered early-phase clinical trials.

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A longitudinal study of SARS-CoV-2-infected patients reveals a high correlation between neutralizing antibodies and COVID-19 severity

Cellular and Molecular Immunology ◽

10.1038/s41423-020-00588-2 ◽

2021 ◽

Author(s):

Vincent Legros ◽

Solène Denolly ◽

Manon Vogrig ◽

Bertrand Boson ◽

Eglantine Siret ◽

...

Keyword(s):

Intensive Care ◽

Neutralizing Antibodies ◽

Vaccine Development ◽

Surface Protein ◽

Humoral Response ◽

Neutralizing Antibody ◽

Rapid Decline ◽

Serum Samples ◽

Immune Correlates ◽

Human Coronaviruses

AbstractUnderstanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection against reinfection and, thus, for public health policy and vaccine development for COVID-19. In this study, using either live SARS-CoV-2 particles or retroviruses pseudotyped with the SARS-CoV-2 S viral surface protein (Spike), we studied the neutralizing antibody (nAb) response in serum samples from a cohort of 140 SARS-CoV-2 qPCR-confirmed infections, including patients with mild symptoms and also more severe forms, including those that required intensive care. We show that nAb titers correlated strongly with disease severity and with anti-spike IgG levels. Indeed, patients from intensive care units exhibited high nAb titers; conversely, patients with milder disease symptoms had heterogeneous nAb titers, and asymptomatic or exclusive outpatient-care patients had no or low nAbs. We found that nAb activity in SARS-CoV-2-infected patients displayed a relatively rapid decline after recovery compared to individuals infected with other coronaviruses. Moreover, we found an absence of cross-neutralization between endemic coronaviruses and SARS-CoV-2, indicating that previous infection by human coronaviruses may not generate protective nAbs against SARS-CoV-2. Finally, we found that the D614G mutation in the spike protein, which has recently been identified as the current major variant in Europe, does not allow neutralization escape. Altogether, our results contribute to our understanding of the immune correlates of SARS-CoV-2-induced disease, and rapid evaluation of the role of the humoral response in the pathogenesis of SARS-CoV-2 is warranted.

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In silico and in vitro analysis of a multiepitope L1-E7 fusion construct for vaccine development against human papillomaviruses

Letters in Drug Design & Discovery ◽

10.2174/1570180818666210602160150 ◽

2021 ◽

Vol 18 ◽

Author(s):

Elnaz Abbasifarid ◽

Azam Bolhassani ◽

Shiva Irani ◽

Fattah Sotoodehnejadnematalahi

Keyword(s):

Western Blotting ◽

Vaccine Development ◽

Fluorescent Microscopy ◽

Therapeutic Vaccine ◽

Human Papillomaviruses ◽

Mhc I ◽

Fusion Construct ◽

Mhc Ii ◽

Hpv Types

Background: Human papillomavirus (HPV) infection is the major risk factor for cervical cancer. Current prophylactic HPV vaccines provide immunity against most genital and carcinogenic HPV types. However, these vaccines failed to produce immune responses against already established HPV infections. Methods: For the design of a therapeutic vaccine candidate, we utilized immunoinformatics tools to design a potential multiepitope fusion construct based on L1 and E7 genes from different high- and low-risk HPV types. After determination of CD4+ and CD8+ T cell epitopes, the allergenicity, toxicity, immunogenicity, conservancy, and population coverage were analyzed for epitope selection. Then, the hemolytic probability of the selected epitopes, and molecular docking between major histocompatibility complex (MHC) and the chosen epitopes were performed by different web servers. Next, a multiepitope peptide construct consisting of 12 epitopes linked by the AAY proteasomal sequence was designed. After that, physicochemical properties, solubility, secondary and tertiary structures of this construct were evaluated by bioinformatics tools. Finally, after amino acid reverse translation of the multiepitope peptide construct, expression of the L1-E7 DNA construct (pEGFP-L1-E7) was investigated in HEK-293T cells using fluorescent microscopy, flow cytometry, and western blotting. Results: Considering various parameters, the immunodominant peptides such as L1(MHC-I)-DLDQFPLGRKFLLQ, L1(MHC-II)-NQLFVTVVDTTRSTN, E7-HPV16(MHC-I)-AEPDRAHYNIVTF, E7-HPV18(MHC-I)-HGPKATVQDIVLHL, E7-HPV31(MHC-I)-KPDTSNYNIVTF, E7-HPV33(MHC-I)-RPDGQAQPATADYYI, E7-HPV45(MHC-I)- RTLQQLFLSFV, E7-HPV16(MHC-II)-TLHEYMLDLQPETTD, E7-HPV18(MHC-II)-LRAFQQLFLNTLSFV, E7-HPV31(MHC-II)-PTLQDYVLDLQPEAT, E7-HPV33(MHC-II)-LKEYVLDLYPEPTDL and E7-HPV45(MHC-II)-LQQLFLSTLSFVCPW were determined to design the vaccine construct. The results indicated efficient expression of the L1-E7 DNA construct (74 ± 2.19%) in vitro. Moreover, the polyepitope peptide generated in the cells was detected as a clear band of ~ 50 kDa in western blotting. Conclusion: Regarding the favorable transfection efficiency of the designed L1-E7 multiepitope construct, in vivo validation study on its therapeutic potential is underway.

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Broad Neutralization Responses Against Oncogenic Human Papillomaviruses Induced by a Minor Capsid L2 Polytope Genetically Incorporated Into Bacterial Ferritin Nanoparticles

Frontiers in Immunology ◽

10.3389/fimmu.2020.606569 ◽

2020 ◽

Vol 11 ◽

Author(s):

Fan Yang ◽

Filipe C. Mariz ◽

Xueer Zhao ◽

Gloria Spagnoli ◽

Simone Ottonello ◽

...

Keyword(s):

Cervical Cancer ◽

Capsid Protein ◽

Pyrococcus Furiosus ◽

Neutralizing Antibody ◽

Hpv Infection ◽

Cross Reactivity ◽

Human Papillomaviruses ◽

Promising Alternative ◽

Peptide Epitope ◽

Hpv Types

Cervical cancer remains a global health burden despite the introduction of highly effective vaccines for the prophylaxis of causative human papillomavirus infection (HPV). Current efforts to eradicate cervical cancer focus on the development of broadly protective, cost-effective approaches. HPV minor capsid protein L2 is being recognized as a promising alternative to the major capsid protein L1 because of its ability to induce responses against a wider range of different HPV types. However, a major limitation of L2 as a source of cross-neutralizing epitopes is its lower immunogenicity compared to L1 when assembled into VLPs. Various approaches have been proposed to overcome this limitation, we developed and tested ferritin-based bio-nanoparticles displaying tandemly repeated L2 epitopes from eight different HPV types grafted onto the surface of Pyrococcus furiosus thioredoxin (Pf Trx). Genetic fusion of the Pf Trx-L2(8x) module to P. furiosus ferritin (Pf Fe) did not interfere with ferritin self-assembly into an octahedral structure composed by 24 protomers. In guinea pigs and mice, the ferritin super-scaffolded, L2 antigen induced a broadly neutralizing antibody response covering 14 oncogenic and two non-oncogenic HPV types. Immune-responsiveness lasted for at least one year and the resulting antibodies also conferred protection in a cervico-vaginal mouse model of HPV infection. Given the broad organism distribution of thioredoxin and ferritin, we also verified the lack of cross-reactivity of the antibodies elicited against the scaffolds with human thioredoxin or ferritin. Altogether, the results of this study point to P. furiosus ferritin nanoparticles as a robust platform for the construction of peptide-epitope-based HPV vaccines.

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Minor capsid protein L2 polytope induces broad protection against oncogenic and mucosal human papillomaviruses

Journal of Virology ◽

10.1128/jvi.01930-17 ◽

2017 ◽

pp. JVI.01930-17 ◽

Cited By ~ 4

Author(s):

Somayeh Pouyanfard ◽

Gloria Spagnoli ◽

Lorenzo Bulli ◽

Kathrin Balz ◽

Fan Yang ◽

...

Keyword(s):

Capsid Protein ◽

Vaccine Design ◽

Neutralizing Antibody ◽

Human Papillomaviruses ◽

Minor Capsid Protein ◽

Wide Range ◽

Hpv Types ◽

Prophylactic Vaccines ◽

Oncogenic Hpv ◽

Single Peptide

The amino terminus of the human papillomavirus minor capsid protein L2 contains a major cross-neutralization epitope which provides the basis for the development of a broadly protecting HPV vaccine. Wide range of protection against different HPV types would eliminate one of the major drawbacks of the commercial, L1 based prophylactic vaccines. Previously, we have reported that insertion of the L2 epitope into a scaffold composed of bacterial thioredoxin protein generates a potent antigen inducing comprehensive protection against different animal and human papillomaviruses. We also reported, however, that although protection is broad, some oncogenic HPV types escape the neutralizing antibody response, if L2 epitopes from single HPV types are used as immunogen. We were able to compensate for this by applying a mix of thioredoxin proteins carrying L2 epitopes from HPV types 16, 31, and 51. As the development of a cost-efficient HPV prophylactic vaccines is one of our objectives, this approach is not feasible as it requires the development of multiple good manufacturing production processes in combination with a complex vaccine formulation. Here we report the development of a thermostable thioredoxin based single peptide vaccine carrying an L2 polytope of up to 11 different HPV types. The L2 polytope antigens have excellent abilities in respect to broadness of protection and robustness of induced immune responses. To further increase immunogenicity, we fused the thioredoxin L2 polytope antigen with a heptamerization domain. In the final vaccine design, we achieve protective responses against all 14 oncogenic HPV types we have analyzed plus the low risk HPV types 6 and 11 and a number of cutaneous HPVs.ImportanceInfections by a large number of human papillomaviruses lead to malignant and non-malignant disease. Current commercial vaccines based on virus-like particles effectively protect against some HPV types but fail to do so for most others. Further, only about a third of all countries have access to the VLP vaccines. The minor capsid protein L2 has been shown to contain so called neutralization epitopes within its N-terminus. We designed polytopes comprising the L2 epitope amino acids 20-38 of up to 11 different mucosal HPV types and inserted them into the scaffold of thioredoxin derived from a thermophile achaebacterium. The antigen induced neutralizing antibody responses in mice and guinea pigs against 26 mucosal and cutaneous HPV types. Further, addition of a heptamerization domain significantly increased the immunogenicity. The final vaccine design comprising an heptamerized L2 8mer thioredoxin single peptide antigen with excellent thermal stability might overcome some of the limitations of the current VLP vaccines.

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A longitudinal study of SARS-CoV-2 infected patients shows high correlation between neutralizing antibodies and COVID-19 severity

10.1101/2020.08.27.20182493 ◽

2020 ◽

Author(s):

Vincent Legros ◽

Solène Denolly ◽

Manon Vogrig ◽

Bertrand Boson ◽

Josselin Rigaill ◽

...

Keyword(s):

Intensive Care ◽

Neutralizing Antibodies ◽

Vaccine Development ◽

Surface Protein ◽

Humoral Response ◽

Neutralizing Antibody ◽

Severe Form ◽

Rapid Decline ◽

Previous Infection ◽

Human Coronaviruses

Understanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection from re-infection and, thus, for public health policy and for vaccine development against the COVID-19. Here, using either live SARS-CoV-2 particles or retroviruses pseudotyped with the SARS-CoV-2 S viral surface protein (Spike), we studied the neutralizing antibody (nAb) response in serum specimens from a cohort of 140 SARS-CoV-2 qPCR-confirmed patients, including patient with mild symptoms but also more severe form including those that require intensive care. We show that nAb titers were strongly correlated with disease severity and with anti-Spike IgG levels. Indeed, patients from intensive care units exhibited high nAb titers, whereas patients with milder disease symptoms displayed heterogenous nAb titers and asymptomatic or exclusive outpatient care patients had no or poor nAb levels. We found that the nAb activity in SARS-CoV-2-infected patients displayed a relatively rapid decline after recovery, as compared to individuals infected with alternative coronaviruses. We show the absence of cross-neutralization between endemic coronaviruses and SARS-CoV-2, indicating that previous infection by human coronaviruses may not generate protective nAb against SARS-CoV-2 infection. Finally, we found that the D614G mutation in the Spike protein, which has recently been identified as the major variant now found in Europe, does not allow neutralization escape. Altogether, our results contribute to the understanding of the immune correlate of SARS-CoV-2 induced disease and claim for a rapid evaluation of the role of the humoral response in the pathogenesis of SARS-CoV-2.

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Robust Neutralizing Antibodies to SARS-CoV-2 Develop and Persist in Subjects with Diabetes and COVID-19 Pneumonia

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgab055 ◽

2021 ◽

Cited By ~ 1

Author(s):

Stefania Dispinseri ◽

Vito Lampasona ◽

Massimiliano Secchi ◽

Andrea Cara ◽

Elena Bazzigaluppi ◽

...

Keyword(s):

Antibody Response ◽

Neutralizing Antibodies ◽

Vaccine Development ◽

Lentiviral Vector ◽

Vaccination Campaign ◽

Humoral Response ◽

Neutralizing Antibody ◽

Glucose Levels ◽

Increased Risk ◽

Patients With Diabetes

Abstract Context Demonstrating the ability to mount a neutralizing antibody response to SARS-CoV-2 in the presence of diabetes is crucial to understand COVID-19 pathogenesis, reinfection potential, and vaccine development. Objective The aim of this study was to characterize the kinetics and durability of neutralizing antibody (Nab) response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the presence of hyperglycemia. Methods Using a lentiviral vector–based SARS-CoV-2 neutralization assay to measure Nabs, we characterized 150 patients randomly selected from a cohort of 509 patients with confirmed COVID-19 pneumonia. We analyzed Nab response according to the presence of diabetes or hyperglycemia, at the time of hospitalization and during the postdischarge follow-up: 1-, 3-, and 6-month outpatient visits. Results Among 150 randomly selected patients 40 (26.6%) had diabetes. Diabetes (hazard ratio [HR] 8.9, P < .001), glucose levels (HR 1.25 × 1.1 mmol/L, P < .001), and glucose variability (HR 1.17 × 0.6 mmol/L, P < .001) were independently associated with an increased risk of mortality. The neutralizing activity of SARS-CoV-2 antibodies in patients with diabetes was superimposable, as for kinetics and extent, to that of patients without diabetes. It was similar across glucose levels and correlated with the humoral response against the SARS-CoV-2 spike protein. Positivity for Nabs at the time of hospital admission conferred protection on mortality, both in the presence (HR 0.28, P = .046) or absence of diabetes (HR 0.26, P = .030). The longevity of the Nab response was not affected by diabetes. Conclusion Diabetes and hyperglycemia do not affect the kinetics and durability of the neutralizing antibody response to SARS-CoV-2. These findings provide the rational to include patients with diabetes in the early phase of the vaccination campaign against SARS-CoV-2.

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Poor neutralizing antibody responses in 106 patients with WM after vaccination against SARS-CoV-2; a prospective study

Blood Advances ◽

10.1182/bloodadvances.2021005444 ◽

2021 ◽

Author(s):

Maria Gavriatopoulou ◽

Evangelos Terpos ◽

Ioannis Ntanasis-Stathopoulos ◽

Alexandros Briasoulis ◽

Sentiljana Gumeni ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Hematological Malignancies ◽

Kinase Inhibitors ◽

Vaccine Development ◽

Humoral Response ◽

Neutralizing Antibody ◽

Control Measures ◽

Infection Control Measures ◽

A Prospective Study ◽

Lower Production

The urgency of the COVID-19 pandemic has led to accelerated vaccine development within less than a year. Immunocompromised patients with hematological malignancies are more susceptible to COVID-19 and at higher risk of severe complications and worse outcomes compared with general population. In this context, we evaluated the humoral response by determining the titers of neutralizing antibodies (NAbs) against SARS-CoV-2 in patients with Waldenstrom Macroglobulinemia (WM) after vaccination with the BNT162b2 or AZD1222 vaccine. An FDA-approved, ELISA-based methodology was implemented to evaluate NAbs on the day of the first vaccine shot, as well as on day 22 and 50 afterwards. 106 patients with WM (43% males, median age 73 years) and 212 healthy controls (46% males, median age 66 years) who were vaccinated during the same period, at the same center were enrolled in the study (which is registered at www.clinicaltrials.gov as NCT04743388). Our data indicate that vaccination with either 2 doses of the BNT162b2 or 1 dose of the AZD1222 vaccine leads to lower production of NAbs against SARS-CoV-2 in patients with WM compared with controls both on day 22 and on day 50 (P<0.001 for all comparisons). Disease-related immune dysregulation and therapy-related immunosuppression are involved in the low humoral response. Importantly, active treatment with either Rituximab or Bruton's Tyrosine Kinase inhibitors was proven as an independent prognostic factor for suboptimal antibody response following vaccination. In conclusion, patients with WM have low humoral response following COVID-19 vaccination, which underlines the need for timely vaccination ideally during a treatment-free period and for continuous vigilance on infection control measures.

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Towards Quantitative and Standardized Serological and Neutralization Assays for COVID-19

International Journal of Molecular Sciences ◽

10.3390/ijms22052723 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2723

Author(s):

Linhua Tian ◽

Elzafir B. Elsheikh ◽

Paul N. Patrone ◽

Anthony J. Kearsley ◽

Adolfas K. Gaigalas ◽

...

Keyword(s):

Flow Cytometry ◽

Vaccine Development ◽

Neutralizing Antibody ◽

Epidemiologic Studies ◽

Cross Reactivity ◽

Receptor Binding Domain ◽

Proof Of Concept ◽

Reference Standard ◽

Improve Measurement ◽

Antibody Titers

Quantitative and robust serology assays are critical measurements underpinning global COVID-19 response to diagnostic, surveillance, and vaccine development. Here, we report a proof-of-concept approach for the development of quantitative, multiplexed flow cytometry-based serological and neutralization assays. The serology assays test the IgG and IgM against both the full-length spike antigens and the receptor binding domain (RBD) of the spike antigen. Benchmarking against an RBD-specific SARS-CoV IgG reference standard, the anti-SARS-CoV-2 RBD antibody titer was quantified in the range of 37.6 µg/mL to 31.0 ng/mL. The quantitative assays are highly specific with no correlative cross-reactivity with the spike proteins of MERS, SARS1, OC43 and HKU1 viruses. We further demonstrated good correlation between anti-RBD antibody titers and neutralizing antibody titers. The suite of serology and neutralization assays help to improve measurement confidence and are complementary and foundational for clinical and epidemiologic studies.

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Genetic diversity of cutaneous human papillomaviruses

Journal of General Virology ◽

10.1099/vir.0.82911-0 ◽

2007 ◽

Vol 88 (10) ◽

pp. 2662-2669 ◽

Cited By ~ 50

Author(s):

Ola Forslund

Keyword(s):

Genetic Diversity ◽

Phylogenetic Analysis ◽

Human Skin ◽

Human Papillomaviruses ◽

Sequence Identity ◽

Hpv Types

Human papillomaviruses (HPVs) of the genera Betapapillomavirus and Gammapapillomavirus are common on human skin. Sequencing of subgenomic amplicons of cutaneous HPVs has revealed a large number of novel putative HPV types within these genera. Phylogenetic analysis based on these amplicons revealed 133 putative HPV types with <90 % sequence identity to any known HPV type or to each other. As there are already 34 characterized HPV types described within the genera Betapapillomavirus and Gammapapillomavirus, they appear to be the most genetically diverse of the HPVs, apparently comprising at least 167 different HPV types.

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