• The 3D structure of Kaposi sarcoma herpesvirus LANA C-terminal domain bound to DNA.

      Hellert, Jan; Weidner-Glunde, Magdalena; Krausze, Joern; Lünsdorf, Heinrich; Ritter, Christiane; Schulz, Thomas F; Lührs, Thorsten (2015-05-26)
      Kaposi sarcoma herpesvirus (KSHV) persists as a latent nuclear episome in dividing host cells. This episome is tethered to host chromatin to ensure proper segregation during mitosis. For duplication of the latent genome, the cellular replication machinery is recruited. Both of these functions rely on the constitutively expressed latency-associated nuclear antigen (LANA) of the virus. Here, we report the crystal structure of the KSHV LANA DNA-binding domain (DBD) in complex with its high-affinity viral target DNA, LANA binding site 1 (LBS1), at 2.9 Å resolution. In contrast to homologous proteins such as Epstein-Barr virus nuclear antigen 1 (EBNA-1) of the related γ-herpesvirus Epstein-Barr virus, specific DNA recognition by LANA is highly asymmetric. In addition to solving the crystal structure, we found that apart from the two known LANA binding sites, LBS1 and LBS2, LANA also binds to a novel site, denoted LBS3. All three sites are located in a region of the KSHV terminal repeat subunit previously recognized as a minimal replicator. Moreover, we show that the LANA DBD can coat DNA of arbitrary sequence by virtue of a characteristic lysine patch, which is absent in EBNA-1 of the Epstein-Barr virus. Likely, these higher-order assemblies involve the self-association of LANA into supermolecular spirals. One such spiral assembly was solved as a crystal structure of 3.7 Å resolution in the absence of DNA. On the basis of our data, we propose a model for the controlled nucleation of higher-order LANA oligomers that might contribute to the characteristic subnuclear KSHV microdomains ("LANA speckles"), a hallmark of KSHV latency.
    • Detection of anti-HPV11-L1 antibodies in immune sera from patients suffering from recurrent respiratory papillomatosis using ELISA.

      Durzyńska, Julia; Błazejewska, Paulina; Szydłowski, Jarosław; Goździcka-Józefiak, Anna; Department of Molecular Virology, Faculty of Biology, University of A. Mickiewicz, Poznan, Poznan. juliadur@amu.edu.pl (2010-08)
      Infection with human papillomaviruses (mostly HPV6 and HPV11) may lead to recurrent respiratory papillomatosis (RRP), a chronic disease affecting 2-4/100,000 people. Papillomas have to be removed surgically so patients can breathe normally. Papillomas often grow back and some patients are subjected to a number of operations. In general, asymptomatic HPV-positive people have low levels of antiviral antibodies in their sera, as the human humoral response is weak due to HPV's biology. In patients suffering from RRP who have undergone multiple surgeries, a blood-epithelium barrier breach stimulates the production of anti-HPV antibodies. Our study's aim was to produce HisTag-HPV11-L1 major capsid protein in E. coli cells, and to purify it. We also sought to detect anti-HPV11-L1 antibodies in antisera obtained from RRP patients using ELISA. Clinical samples were collected from 47 patients with RRP (antisera and papillomas), and from 32 controls (sera and oral swabs), from the Wielkopolska region of Poland. Antisera and control sera were used to coat microplates, HisTag-HPV11-L1 antigen was applied, and antibody-antigen complexes were detected by anti-HisTag monoclonal antibody in an ELISA assay. Simultaneously, total cellular DNA was extracted from papillomas and oral squamous cells obtained from controls. All DNA samples were screened for HPV DNA using MY-PCR. All patients were HPV-positive (30% for HPV6 and 70% for HPV11). Statistically significant correlations were found between the amount of anti-HPV11-L1 antibodies in the sera of RRP patients and the number of surgical procedures they underwent. Although HPV virus-like particles are most often used for anti-HPV antibody detection, the ELISA method presented herein is another viable option for use in RRP patients.