TY  - JOUR
AB  - BACKGROUND: Infection with the Epstein-Barr virus (EBV) elicits a complex T-cell response against a broad range of viral proteins. Hence, identifying potential differences in the cellular immune response of patients with different EBV-associated diseases or different courses of the same disorder requires interrogation of a maximum number of EBV antigens. Here, we tested three novel EBV-derived antigen formulations for their ability to reactivate virus-specific T cells ex vivo in patients with EBV-associated infectious mononucleosis (IM). METHODS: We comparatively analyzed EBV-specific CD4+ and CD8+ T-cell responses to three EBV-derived antigen formulations in 20 pediatric patients during the early phase of IM: T-activated EBV proteins (BZLF1, EBNA3A) and EBV-like particles (EB-VLP), both able to induce CD4+ and CD8+ T-cell responses ex vivo, as well as an EBV-derived peptide pool (PP) covering 94 well-characterized CD8+ T-cell epitopes. We assessed the specificity, magnitude, kinetics, and functional characteristics of EBV-specific immune responses at two sequential time points (v1 and v2) within the first six weeks after IM symptom onset (Tonset). RESULTS: All three tested EBV-derived antigen formulations enabled the detection of EBV-reactive T cells during the early phase of IM without prior T-cell expansion in vitro. EBV-reactive CD4+ and CD8+ T cells were mainly mono-functional (CD4+: mean 64.92%, range 56.15-71.71%; CD8+: mean 58.55%, range 11.79-85.22%) within the first two weeks after symptom onset (v1) with IFN-γ and TNF-secreting cells representing the majority of mono-functional EBV-reactive T cells. By contrast, PP-reactive CD8+ T cells were primarily bi-functional (>60% at v1 and v2), produced IFN-γ and TNF and had more tri-functional than mono-functional components. We observed a moderate correlation between viral load and EBNA3A, EB-VLP, and PP-reactive CD8+ T cells (rs = 0.345, 0.418, and 0.356, respectively) within the first two weeks after Tonset, but no correlation with the number of detectable EBV-reactive CD4+ T cells. CONCLUSIONS: All three EBV-derived antigen formulations represent innovative and generic recall antigens suitable for monitoring EBV-specific T-cell responses ex vivo. Their combined use facilitates a thorough analysis of EBV-specific T-cell immunity and allows the identification of functional T-cell signatures linked to disease development and severity.
AU  - Fischer, F.*
AU  - Mücke, J.*
AU  - Werny, L.
AU  - Gerrer, K.*
AU  - Mihatsch, L.*
AU  - Zehetmaier, S.
AU  - Riedel, I.*
AU  - Geisperger, J.*
AU  - Bodenhausen, M.*
AU  - Schulte-Hillen, L.*
AU  - Hoffmann, D.
AU  - Protzer, U.
AU  - Mautner, J.
AU  - Behrends, U.
AU  - Bauer, T.
AU  - Körber, N.
C1  - 70841
C2  - 55949
TI  - Evaluation of novel Epstein-Barr virus-derived antigen formulations for monitoring virus-specific T cells in pediatric patients with infectious mononucleosis.
JO  - Virol. J.
VL  - 21
IS  - 1
PY  - 2024
ER  - 

TY  - JOUR
AB  - BACKGROUND: Human adenoviruses (HAdVs) frequently cause common respiratory or gastrointestinal infections among children, adults, individuals with immune deficiencies, and other vulnerable populations with varying degree of symptoms, ranging from mild to server, and in some cases, even fatalities. Despite the significant clinical impact of HAdVs, there is currently no approved vaccine available. METHODS: This study explores the potential of the adenovirus type 5 fiber knob (Ad5-FK) to stimulate the production of Ad-specific neutralizing antibodies and T-cell responses in mice. Based on structure predictions, we first expressed Ad5-FK in E. coli and confirmed the assembly of FK into its trimeric form. After testing the binding capability of the trimeric FK to susceptible cells, the immunogenicity of the protein in combination with the c-di-AMP adjuvant was assessed in BALB/c mice. RESULTS: The purified Ad5-FK exhibited self-trimerization and maintained correct conformation akin to the authentic FK structure. This facilitated effective binding to susceptible HEK293 cells. Notably, the protein demonstrated significant inhibition of HEK293 cells infection by rAd5-GFP. Immunization of BALB/c mice with Ad5-FK, or Ad5-FK mixed with c-di-AMP yielded FK-specific antibodies with potent neutralization capacity. Significantly, Ad5-FK was found to elicit a vigorous CD4+ T-cell response in the immunized mice. CONCLUSION: Our findings underscore the efficacy of FK-based vaccine in eliciting anti-Ad humoral immune response and CD4 T-cell immune reactions essential for protection against viral infections.
AU  - Orabi, A.*
AU  - Shameli, K.*
AU  - Protzer, U.
AU  - Moeini, H.*
C1  - 71940
C2  - 56537
TI  - Adenoviral fiber-knob based vaccination elicits efficient neutralizing antibodies and T cell responses against adenovirus infection.
JO  - Virol. J.
VL  - 21
IS  - 1
PY  - 2024
ER  - 

TY  - JOUR
AB  - Background: Measuring specific anti-SARS-CoV-2 antibodies has become one of the main epidemiological tools to survey the ongoing SARS-CoV-2 pandemic, but also vaccination response. The WHO made available a set of well-characterized samples derived from recovered individuals to allow normalization between different quantitative anti-Spike assays to defined Binding Antibody Units (BAU). Methods: To assess sero-responses longitudinally, a cohort of ninety-nine SARS-CoV-2 RT-PCR positive subjects was followed up together with forty-five vaccinees without previous infection but with two vaccinations. Sero-responses were evaluated using a total of six different assays: four measuring anti-Spike proteins (converted to BAU), one measuring anti-Nucleocapsid proteins and one SARS-CoV-2 surrogate virus neutralization. Both cohorts were evaluated using the Euroimmun Anti-SARS-CoV-2-ELISA anti-S1 IgG and the Roche Elecsys Anti-SARS-CoV-2 anti-S1 assay. Results: In SARS-CoV-2-convalesce subjects, the BAU-sero-responses of Euroimmun Anti-SARS-CoV-2-ELISA anti-S1 IgG and Roche Elecsys Anti-SARS-CoV-2 anti-S1 peaked both at 47 (43–51) days, the first assay followed by a slow decay thereafter (> 208 days), while the second assay not presenting any decay within one year. Both assay values in BAUs are only equivalent a few months after infection, elsewhere correction factors up to 10 are necessary. In contrast, in infection-naive vaccinees the assays perform similarly. Conclusion: The results of our study suggest that the establishment of a protective correlate or vaccination booster recommendation based on different assays, although BAU-standardised, is still challenging. At the moment the characteristics of the available assays used are not related, and the BAU-standardisation is unable to correct for that.
AU  - Kroidl, I.*
AU  - Winter, S.*
AU  - Rubio-Acero, R.*
AU  - Bakuli, A.*
AU  - Geldmacher, C.*
AU  - Eser, T.M.*
AU  - Deák, F.*
AU  - Horn, S.*
AU  - Zielke, A.*
AU  - Ahmed, M.I.M.*
AU  - Diepers, P.*
AU  - Guggenbühl, J.*
AU  - Frese, J.*
AU  - Bruger, J.*
AU  - Puchinger, K.*
AU  - Reich, J.*
AU  - Falk, P.*
AU  - Markgraf, A.*
AU  - Fensterseifer, H.*
AU  - Paunovic, I.*
AU  - Thomschke, A.*
AU  - Pritsch, M.*
AU  - Riess, F.*
AU  - Saathoff, E.*
AU  - Hoelscher, M.*
AU  - Olbrich, L.*
AU  - Castelletti, N.
AU  - Wieser, A.*
C1  - 68329
C2  - 54753
CY  - Campus, 4 Crinan St, London N1 9xw, England
TI  - Studying temporal titre evolution of commercial SARS-CoV-2 assays reveals significant shortcomings of using BAU standardization for comparison.
JO  - Virol. J.
VL  - 20
IS  - 1
PB  - Bmc
PY  - 2023
ER  - 

TY  - JOUR
AB  - Background: Heterogenous nuclear ribonucleoproteins (hnRNPs) control many processes of the gene expression machinery including mRNA transcription, splicing, export, stability and translation. Recent data show interaction of the HIV-1 Rev regulatory protein with a subset of hnRNP proteins, that includes hnRNP Q, suggesting that hnRNPs can contribute to regulation of HIV-1 gene expression by Rev. Findings: In this work we address the effect of hnRNP Q on Rev-dependent gene expression. We show that hnRNP Q overexpression increased levels of proteins produced from a Rev-dependent reporter gene in the presence of Rev. Increased protein levels did not correlate with changes in either the levels or the nucleocytoplasmic distribution of Rev-dependent reporter mRNAs. Similar observations were made in persistently HIV-1 infected HeLa cells. In these cells, hnRNP Q overexpression increased levels of the HIV-1 Gag-p24 protein, while levels of viral Rev-dependent mRNAs were not affected. Conclusion: Our data indicate that hnRNP Q can stimulate the protein production of Rev-dependent mRNAs without changing mRNA levels and mRNA export, respectively. This suggests that hnRNP Q can boost HIV gene expression at the level of protein production.
AU  - Vincendeau, M.
AU  - Nagel, D.
AU  - Brenke, J.K.
AU  - Brack-Werner, R.
AU  - Hadian, K.
C1  - 25517
C2  - 31871
TI  - Heterogenous nuclear ribonucleoprotein Q increases protein expression from HIV-1 Rev-dependent transcripts.
JO  - Virol. J.
VL  - 10
PB  - Biomed Central
PY  - 2013
ER  - 

TY  - JOUR
AB  - Background: Murine gammaherpesvirus 68 (MHV-68) is used as a model to study the function of gammaherpesvirus glycoproteins. gp150 of MHV-68, encoded by open reading frame M7, is a positional homolog of gp350/220 of EBV and of gp35/37 of KSHV. Since it had been proposed that gp350/220 of EBV might be a suitable vaccine antigen to protect from EBV-associated diseases, gp150 has been applied as a model vaccine in the MHV-68 system. When analyzing the function of gp150, previous studies yielded conflicting results on the role of gp150 in latency amplification, and disparities between the mutant viruses which had been analyzed were blamed for the observed differences. Results: To further develop MHV-68 as model to study the function of gammaherpesvirus glycoproteins in vivo, it is important to know whether gp150 contributes to latency amplification or not. Thus, we re-evaluated this question by testing a number of gp150 mutants side by side. Our results suggest that gp150 is dispensable for latency amplification. Furthermore, we investigated the effect of vaccination with gp150 using gp150-containing exosomes. Vaccination with gp150 induced a strong humoral and cellular immune response, yet it did not affect a subsequent MHV-68 challenge infection. Conclusions: In this study, we found no evidence for a role of gp150 in latency amplification. The previously observed contradictory results on the role of gp150 in latency amplification were not related to differences between the mutant viruses which had been used.
AU  - Ruiss, R.
AU  - Ohno, S.
AU  - Steer, B.
AU  - Zeidler, R.*
AU  - Adler, H.
C1  - 10454
C2  - 30257
TI  - Murine gammaherpesvirus 68 glycoprotein 150 does not contribute to latency amplification in vivo.
JO  - Virol. J.
VL  - 9
PB  - Biomed Central Ltd.
PY  - 2012
ER  - 

TY  - JOUR
AB  - BACKGROUND: HIV-1 infected individuals are under chronic exposure to reactive oxygen species (ROS) considered to be instrumental in the progression of AIDS and the development of HIV-1 associated dementia (HAD). Astrocytes support neuronal function and protect them against cytotoxic substances including ROS. The protein HIV-1 Nef, a progression factor in AIDS pathology is abundantly expressed in astrocytes in patients with HAD, and thus may influence its functions. RESULTS: Endogenous expressed HIV-1 Nef leads to increased sensitivity of human astrocytes towards exogenous hydrogen peroxide but not towards TNF-alpha. Cell death of nef-expressing astrocytes exposed to 10 μM hydrogen peroxide for 30 min occurred within 4 h. CONCLUSION: HIV-1 Nef may contribute to neuronal dysfunction and the development of HAD by causing death of astrocytes through decreasing their tolerance for hydrogen peroxide.
AU  - Masanetz, S.
AU  - Lehmann, M.H.
C1  - 6555
C2  - 28874
TI  - HIV-1 Nef increases astrocyte sensitivity towards exogenous hydrogen peroxide.
JO  - Virol. J.
VL  - 8
PB  - Biomed Central Ltd.
PY  - 2011
ER  - 

TY  - JOUR
AB  - CONTEXT: Chronic HBV infection is a major cause of hepatocellular carcinoma (HCC) which meanwhile has become the 5th most reason for a fatal outcome of cancer. Worldwide, approximately 350 million people are chronically HBV infected and as such of risk to develop HCC, of those an estimated high rate of children. Treatment of chronic infection is sufficient to reduce the rate of HCC but the rate of sustained virological response remains to low, not at least due to emergence of resistant virus strains. Less is known on HBV infection in children despite the extremely high rate of chronicity. OBJECTIVE, DESIGN, SETTING, AND PATIENT: The case of a nine years old male with a 6 year history of chronic HBV infection, of those 5 years with antiviral treatment is described. INTERVENTIONS AND MAIN OUTCOME MEASURE(S): Before our lab was consulted, the patient was unsuccessfully treated with interferon, an obscure drug named Hepon, which should activate antiviral immune response, and Lamivudine, the latter most likely becoming ineffective due to the mergence of resistant subpopulations (rtL180 M, rtV207 M, two strains with stop codons at position rt188 and rt198, rtM204V (YVDD), rtM204K (YKDD)). Replacement of Lamivudine by adefovir displayed no advantage despite the lack of resistance mutations, thus no decrease in viremia was observed under adefovir treatment. RESULTS AND CONCLUSIONS: Novel mutations in the YMDD motif and its direct neighbourhood were observed, both being compatible with Lamivudine resistance. No mutations were found that are associated with ADF resistance. Both, the clinical course of treatment and the genotypic resistance profile emphasize the need for systematic analyses of the HBV resistance mechanisms and structured therapy concept also for children chronically infected with HBV.
AU  - Schildgen, V.
AU  - Ziegler, S.*
AU  - Tillmann, R.L.*
AU  - Schildgen, O.*
C1  - 5734
C2  - 27561
TI  - Novel mutation in YMDD motif and direct neighbourhood in a child with chronic HBV-infection and clinical lamivudine and adefovir resistance - a scholarly case.
JO  - Virol. J.
VL  - 7
PB  - BioMed Central Ltd.
PY  - 2010
ER  -