Papillomavirus pseudovirions packaged with the L2 gene induce cross-neutralizing antibodies

<p>Abstract</p> <p>Background</p> <p>Current vaccines against HPVs are constituted of L1 protein self-assembled into virus-like particles (VLPs) and they have been shown to protect against natural HPV16 and HPV18 infections and associated lesions. In addition, limited cross-protection has been observed against closely related types. Immunization with L2 protein in animal models has been shown to provide cross-protection against distant papillomavirus types, suggesting that the L2 protein contains cross-neutralizing epitopes. However, vaccination with L2 protein or L2 peptides does not induce high titers of anti-L2 antibodies. In order to develop a vaccine with the potential to protect against other high-risk HPV types, we have produced HPV58 pseudovirions encoding the HPV31 L2 protein and compared their capacity to induce cross-neutralizing antibodies with that of HPV L1 and HPV L1/L2 VLPs.</p> <p>Methods</p> <p>The titers of neutralizing antibodies against HPV16, HPV18, HPV31 and HPV58 induced in Balb/c mice were compared after immunization with L2-containing vaccines.</p> <p>Results</p> <p>Low titers of cross-neutralizing antibodies were detected in mice when immunized with L1/L2 VLPs, and the highest levels of cross-neutralizing antibodies were observed in mice immunized with HPV 58 L1/L2 pseudovirions encoding the HPV 31 L2 protein.</p> <p>Conclusions</p> <p>The results obtained indicate that high levels of cross-neutralizing antibodies are only observed after immunization with pseudovirions encoding the L2 protein. HPV pseudovirions thus represent a possible new strategy for the generation of a broad-spectrum vaccine to protect against high-risk HPVs and associated neoplasia.</p

Merkel Cell Polyomavirus Strains in Patients with Merkel Cell Carcinoma

We investigated whether Merkel cell carcinoma (MCC) patients in France carry Merkel cell polyomavirus (MCPyV) and then identified strain variations. All frozen MCC specimens and 45% of formalin-fixed and paraffin-embedded specimens, but none of the non-MCC neuroendocrine carcinomas specimens, had MCPyV. Strains from France and the United States were similar

Prevalence of IgG antibodies against Malawi polyomavirus in patients with autoimmune diseases and lymphoproliferative disorders subjected to bone marrow transplantation

IntroductionHuman polyomaviruses (HPyVs) cause persistent/latent infections in a large fraction of the population. HPyV infections may cause severe diseases in immunocompromised patients. Malawi polyomavirus (MWPyV) is the 10th discovered human polyomavirus (HPyV 10). MWPyV was found in stool samples of healthy children. So far, the few investigations carried out on HPyV 10 did not find an association with human disease.MethodsIn this study, to verify the putative association between MWPyV and human diseases, MWPyV seroprevalence was investigated in patients affected by i) lymphoproliferative disorders (LPDs) and ii) immune system disorders, i.e., autoimmune diseases (ADs), and in iii) healthy subjects. An indirect ELISA, employing virus-like particles (VLPs) to detect serum IgG antibodies against MWPyV/HPyV 10, was carried out. The study also revealed the prevalence of another polyomavirus, Merkel cell polyomavirus (MCPyV).ResultsSera from patients with distinct autoimmune diseases (n = 44; mean age 20 years) had a prevalence of MWPyV antibodies of 68%, while in patients with lymphoproliferative disorders (n = 15; mean age 14 years), subjected to bone marrow transplantation, the prevalence was 47%. In healthy subjects (n = 66; mean age 13 years), the prevalence of MWPyV antibodies was 67%. Our immunological investigation indicates that MWPyV/HPyV 10 seroconversion occurs early in life and MWPyV/HPyV 10 appears to be another polyomavirus ubiquitous in the human population. A significantly lower MWPyV antibody reactivity together with a lower immunological profile was detected in the sera of LPD patients compared with HS2 (*p &lt; 0.05) (Fisher’s exact test). LPD and AD patients have a similar MCPyV seroprevalence compared with healthy subjects.DiscussionMWPyV seroprevalence indicates that this HPyV is not associated with lymphoproliferative and autoimmune diseases. However, the ability to produce high levels of antibodies against MWPyV appears to be impaired in patients with lymphoproliferative disorders. Immunological investigations indicate that MWPyV seroconversion occurs early in life. MCPyV appears to be a ubiquitous polyomavirus, like other HPyVs, in the human population

Profils virologiques après vaccination anti-HPV

National audienc

Serología para el virus del papiloma humano

Las limitaciones para la utilización de la serología para el estudio del virus del papiloma humano con fines clínicos están asociadas con la gran variedad de subtipos humanos, con las reacciones cruzadas que existen entre diversos genotipos, la diversidad de lesiones precursoras de cáncer y con los sitios blancos de infección. Asimismo, la expresión del virus del papiloma humano en las capas superficiales del epitelio dan origen a una débil presentación de células inmunocompetentes de antígenos virales, lo cual origina una elevación de la respuesta serológica. Distintos esfuerzos se han realizado en décadas previas para desarrollar ensayos serológicos más específicos y sensibles. En muchas investigaciones se ha utilizado una fusión de proteínas y péptidos sintéticos que tienen como principal limitación su escasa sensibilidad y especificidad. Sólo en los últimos años, y principalmente debido al arribo de partículas parecidas a este virus, tenemos disponibles ensayos más sensibles y específicos, ampliamente descritos en este artículo. Este artículo también está disponible en: http://www.insp.mx/ salud/index.htm

Merkel cell polyomavirus

International audienc

Serology for human papillomavirus Serología para el virus del papiloma humano

Difficulties with serology for papillomavirus are associated with the large number of human papillomavirus, cross-reactions between papillomavirus, and to the diversity of lesions and target sites for infection. In addition, the expression of the papillomavirus in the superficial layers of the epithelium gives rise to the weak presentation to immunocompetent cells of viral antigens, which in turn gives rise to a weak serological response. Distinct efforts have been made in previous decades to develop more specific and sensitive serological assays. These former studies use fusion proteins and synthetic peptides, although they remain on the whole uninteresting, due to their lack of sensitivity and specificity. Only in the last few years, and principally due to the advent of various virus-like particles (VLP), have more sensitive and specific assays become available.Las limitaciones para la utilización de la serología para el estudio del virus del papiloma humano con fines clínicos están asociadas con la gran variedad de subtipos humanos, con las reacciones cruzadas que existen entre diversos genotipos, la diversidad de lesiones precursoras de cáncer y con los sitios blancos de infección. Asimismo, la expresión del virus del papiloma humano en las capas superficiales del epitelio dan origen a una débil presentación de células inmunocompetentes de antígenos virales, lo cual origina una elevación de la respuesta serológica. Distintos esfuerzos se han realizado en décadas previas para desarrollar ensayos serológicos más específicos y sensibles. En muchas investigaciones se ha utilizado una fusión de proteínas y péptidos sintéticos que tienen como principal limitación su escasa sensibilidad y especificidad. Sólo en los últimos años, y principalmente debido al arribo de partículas parecidas a este virus, tenemos disponibles ensayos más sensibles y específicos, ampliamente descritos en este artículo

Simian virus 40

International audienc

Epidemiology of MCPyV, HPyV6, HPyV7, HPyV9 and TSPyV polyomaviruses in humans and identification of cross-reactivity

International audienc

Viruses associated with skin and mucosal cancers

International audienc