@article{KasangKalluvyaMajingeetal.2016, author = {Kasang, Christa and Kalluvya, Samuel and Majinge, Charles and Kongola, Gilbert and Mlewa, Mathias and Massawe, Irene and Kabyemera, Rogatus and Magambo, Kinanga and Ulmer, Albrecht and Klinker, Hartwig and Gschmack, Eva and Horn, Anne and Koutsilieri, Eleni and Preiser, Wolfgang and Hofmann, Daniela and Hain, Johannes and M{\"u}ller, Andreas and D{\"o}lken, Lars and Weissbrich, Benedikt and Rethwilm, Axel and Stich, August and Scheller, Carsten}, title = {Effects of Prednisolone on Disease Progression in Antiretroviral-Untreated HIV Infection: A 2-Year Randomized, Double-Blind Placebo-Controlled Clinical Trial}, series = {PLoS One}, volume = {11}, journal = {PLoS One}, number = {1}, doi = {10.1371/journal.pone.0146678}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146479}, pages = {e0146678}, year = {2016}, abstract = {Background HIV-disease progression correlates with immune activation. Here we investigated whether corticosteroid treatment can attenuate HIV disease progression in antiretroviral-untreated patients. Methods Double-blind, placebo-controlled randomized clinical trial including 326 HIV-patients in a resource-limited setting in Tanzania (clinicaltrials.gov NCT01299948). Inclusion criteria were a CD4 count above 300 cells/μl, the absence of AIDS-defining symptoms and an ART-na{\"i}ve therapy status. Study participants received 5 mg prednisolone per day or placebo for 2 years. Primary endpoint was time to progression to an AIDS-defining condition or to a CD4-count below 200 cells/μl. Results No significant change in progression towards the primary endpoint was observed in the intent-to-treat (ITT) analysis (19 cases with prednisolone versus 28 cases with placebo, p = 0.1407). In a per-protocol (PP)-analysis, 13 versus 24 study participants progressed to the primary study endpoint (p = 0.0741). Secondary endpoints: Prednisolone-treatment decreased immune activation (sCD14, suPAR, CD38/HLA-DR/CD8+) and increased CD4-counts (+77.42 ± 5.70 cells/μl compared to -37.42 ± 10.77 cells/μl under placebo, p < 0.0001). Treatment with prednisolone was associated with a 3.2-fold increase in HIV viral load (p < 0.0001). In a post-hoc analysis stratifying for sex, females treated with prednisolone progressed significantly slower to the primary study endpoint than females treated with placebo (ITT-analysis: 11 versus 21 cases, p = 0.0567; PP-analysis: 5 versus 18 cases, p = 0.0051): No changes in disease progression were observed in men. Conclusions This study could not detect any significant effects of prednisolone on disease progression in antiretroviral-untreated HIV infection within the intent-to-treat population. However, significant effects were observed on CD4 counts, immune activation and HIV viral load. This study contributes to a better understanding of the role of immune activation in the pathogenesis of HIV infection.}, language = {en} } @article{KincaidChenCoxetal.2014, author = {Kincaid, Rodney P. and Chen, Yating and Cox, Jennifer E. and Rethwilm, Axel and Sullivan, Christopher S.}, title = {Noncanonical MicroRNA (miRNA) Biogenesis Gives Rise to Retroviral Mimics of Lymphoproliferative and Immunosuppressive Host miRNAs}, series = {mBio}, volume = {5}, journal = {mBio}, number = {2}, issn = {2150-7511}, doi = {10.1128/mBio.00074-14}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117216}, pages = {e00074-14}, year = {2014}, abstract = {MicroRNAs (miRNAs) play regulatory roles in diverse processes in both eukaryotic hosts and their viruses, yet fundamental questions remain about which viruses code for miRNAs and the functions that they serve. Simian foamy viruses (SFVs) of Old World monkeys and apes can zoonotically infect humans and, by ill-defined mechanisms, take up lifelong infections in their hosts. Here, we report that SFVs encode multiple miRNAs via a noncanonical mode of biogenesis. The primary SFV miRNA transcripts (pri-miRNAs) are transcribed by RNA polymerase III (RNAP III) and take multiple forms, including some that are cleaved by Drosha. However, these miRNAs are generated in a context-dependent fashion, as longer RNAP II transcripts spanning this region are resistant to Drosha cleavage. This suggests that the virus may avoid any fitness penalty that could be associated with viral genome/transcript cleavage. Two SFV miRNAs share sequence similarity and functionality with notable host miRNAs, the lymphoproliferative miRNA miR-155 and the innate immunity suppressor miR-132. These results have important implications regarding foamy virus biology, viral miRNAs, and the development of retroviral-based vectors. IMPORTANCE Fundamental questions remain about which viruses encode miRNAs and their associated functions. Currently, few natural viruses with RNA genomes have been reported to encode miRNAs. Simian foamy viruses are retroviruses that are prevalent in nonhuman host populations, and some can zoonotically infect humans who hunt primates or work as animal caretakers. We identify a cluster of miRNAs encoded by SFV. Characterization of these miRNAs reveals evolutionarily conserved, unconventional mechanisms to generate small RNAs. Several SFV miRNAs share sequence similarity and functionality with host miRNAs, including the oncogenic miRNA miR-155 and innate immunity suppressor miR-132. Strikingly, unrelated herpesviruses also tap into one or both of these same regulatory pathways, implying relevance to a broad range of viruses. These findings provide new insights with respect to foamy virus biology and vectorology.}, language = {en} } @article{ShityakovFoersterRethwilmetal.2014, author = {Shityakov, Sergey and F{\"o}rster, Carola and Rethwilm, Axel and Dandekar, Thomas}, title = {Evaluation and Prediction of the HIV-1 Central Polypurine Tract Influence on Foamy Viral Vectors to Transduce Dividing and Growth-Arrested Cells}, doi = {10.1155/2014/487969}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112763}, year = {2014}, abstract = {Retroviral vectors are potent tools for gene delivery and various biomedical applications. To accomplish a gene transfer task successfully, retroviral vectors must effectively transduce diverse cell cultures at different phases of a cell cycle. However, very promising retroviral vectors based on the foamy viral (FV) backbone lack the capacity to efficiently transduce quiescent cells. It is hypothesized that this phenomenon might be explained as the inability of foamy viruses to form a pre-integration complex (PIC) with nuclear import activity in growth-arrested cells, which is the characteristic for lentiviruses (HIV-1). In this process, the HIV-1 central polypurine tract (cPPT) serves as a primer for plus-strand synthesis to produce a "flap" element and is believed to be crucial for the subsequent double-stranded cDNA formation of all retroviral RNA genomes. In this study, the effects of the lentiviral cPPT element on the FV transduction potential in dividing and growth-arrested (G1/S phase) adenocarcinomic human alveolar basal epithelial (A549) cells are investigated by experimental and theoretical methods. The results indicated that the HIV-1 cPPT element in a foamy viral vector background will lead to a significant reduction of the FV transduction and viral titre in growth-arrested cells due to the absence of PICs with nuclear import activity.}, subject = {Evaluation}, language = {en} } @article{BodemRethwilm2013, author = {Bodem, Jochen and Rethwilm, Axel}, title = {Evolution of Foamy Viruses: The Most Ancient of All Retroviruses}, series = {Viruses}, journal = {Viruses}, doi = {10.3390/v5102349}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97312}, year = {2013}, abstract = {Recent evidence indicates that foamy viruses (FVs) are the oldest retroviruses (RVs) that we know and coevolved with their hosts for several hundred million years. This coevolution may have contributed to the non-pathogenicity of FVs, an important factor in development of foamy viral vectors in gene therapy. However, various questions on the molecular evolution of FVs remain still unanswered. The analysis of the spectrum of animal species infected by exogenous FVs or harboring endogenous FV elements in their genome is pivotal. Furthermore, animal studies might reveal important issues, such as the identification of the FV in vivo target cells, which than require a detailed characterization, to resolve the molecular basis of the accuracy with which FVs copy their genome. The issues of the extent of FV viremia and of the nature of the virion genome (RNA vs. DNA) also need to be experimentally addressed.}, language = {en} } @article{KasangUlmerDonhauseretal.2012, author = {Kasang, Christa and Ulmer, Albrecht and Donhauser, Norbert and Schmidt, Barabara and Stich, August and Klinker, Hartwig and Kalluvya, Samuel and Koutsilieri, Eleni and Rethwilm, Axel and Scheller, Carsten}, title = {HIV patients treated with low-dose prednisolone exhibit lower immune activation than untreated patients}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75100}, year = {2012}, abstract = {Background: HIV-associated general immune activation is a strong predictor for HIV disease progression, suggesting that chronic immune activation may drive HIV pathogenesis. Consequently, immunomodulating agents may decelerate HIV disease progression. Methods: In an observational study, we determined immune activation in HIV patients receiving low-dose (5 mg/day) prednisolone with or without highly-active antiretroviral therapy (HAART) compared to patients without prednisolone treatment. Lymphocyte activation was determined by flow cytometry detecting expression of CD38 on CD8(+) T cells. The monocyte activation markers sCD14 and LPS binding protein (LBP) as well as inflammation markers soluble urokinase plasminogen activated receptor (suPAR) and sCD40L were determined from plasma by ELISA. Results: CD38-expression on CD8+ T lymphocytes was significantly lower in prednisolone-treated patients compared to untreated patients (median 55.40\% [percentile range 48.76-67.70] versus 73.34\% [65.21-78.92], p = 0.0011, Mann-Whitney test). Similarly, we detected lower levels of sCD14 (3.6 μg/ml [2.78-5.12] vs. 6.11 μg/ml [4.58-7.70]; p = 0.0048), LBP (2.18 ng/ml [1.59-2.87] vs. 3.45 ng/ml [1.84-5.03]; p = 0.0386), suPAR antigen (2.17 μg/ml [1.65-2.81] vs. 2.56 μg/ml [2.24-4.26]; p = 0.0351) and a trend towards lower levels of sCD40L (2.70 pg/ml [1.90-4.00] vs. 3.60 pg/ml [2.95-5.30]; p = 0.0782). Viral load in both groups was similar (0.8 × 105 ng/ml [0.2-42.4 × 105] vs. 1.1 × 105 [0.5-12.2 × 105]; p = 0.3806). No effects attributable to prednisolone were observed when patients receiving HAART in combination with prednisolone were compared to patients who received HAART alone. Conclusions: Patients treated with low-dose prednisolone display significantly lower general immune activation than untreated patients. Further longitudinal studies are required to assess whether treatment with low-dose prednisolone translates into differences in HIV disease progression.}, subject = {HIV}, language = {en} } @article{JacobsBockSchuchetal.2012, author = {Jacobs, Graeme and Bock, Stefanie and Schuch, Anita and Moschall, Rebecca and Schrom, Eva-Maria and Zahn, Juliane and Reuter, Christian and Preiser, Wolfgang and Rethwilm, Axel and Engelbrecht, Susan and Krekau, Thomas and Bodem, Jochen}, title = {Construction of a high titer Infectious HIV-1 subtype C proviral clone from South Africa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76340}, year = {2012}, abstract = {The Human Immunodeficiency Virus type 1 (HIV-1) subtype C is currently the predominant subtype worldwide. Cell culture studies of Sub-Saharan African subtype C proviral plasmids are hampered by the low replication capacity of the resulting viruses, although viral loads in subtype C infected patients are as high as those from patients with subtype B. Here, we describe the sequencing and construction of a new HIV-1 subtype C proviral clone (pZAC), replicating more than one order of magnitude better than the previous subtype C plasmids. We identify the env-region for being the determinant for the higher viral titers and the pZAC Env to be M-tropic. This higher replication capacity does not lead to a higher cytotoxicity compared to previously described subtype C viruses. In addition, the pZAC Vpu is also shown to be able to down-regulate CD4, but fails to fully counteract CD317.}, subject = {HIV}, language = {en} } @article{SpannausHartlWoehrletal.2012, author = {Spannaus, Ralf and Hartl, Maximilian J. and W{\"o}hrl, Birgitta M. and Rethwilm, Axel and Bodem, Jochen}, title = {The prototype foamy virus protease is active independently of the integrase domain}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75370}, year = {2012}, abstract = {Background: Recently, contradictory results on foamy virus protease activity were published. While our own results indicated that protease activity is regulated by the viral RNA, others suggested that the integrase is involved in the regulation of the protease. Results: To solve this discrepancy we performed additional experiments showing that the protease-reverse transcriptase (PR-RT) exhibits protease activity in vitro and in vivo, which is independent of the integrase domain. In contrast, Pol incorporation, and therefore PR activity in the viral context, is dependent on the integrase domain. To further analyse the regulation of the protease, we incorporated Pol in viruses by expressing a GagPol fusion protein, which supported near wild-type like infectivity. A GagPR-RT fusion, lacking the integrase domain, also resulted in wild-type like Gag processing, indicating that the integrase is dispensable for viral Gag maturation. Furthermore, we demonstrate with a trans-complementation assays that the PR in the context of the PR-RT protein supports in trans both, viral maturation and infectivity. Conclusion: We provide evidence that the FV integrase is required for Pol encapsidation and that the FV PR activity is integrase independent. We show that an active PR can be encapsidated in trans as a GagPR-RT fusion protein.}, subject = {Medizin}, language = {en} } @article{HartlBodemJochheimetal.2011, author = {Hartl, Maximilian J. and Bodem, Jochen and Jochheim, Fabian and Rethwilm, Axel and R{\"o}sch, Paul and W{\"o}hrl, Birgitta M.}, title = {Regulation of foamy virus protease activity by viral RNA}, series = {Retrovirology}, volume = {8}, journal = {Retrovirology}, number = {Suppl. 1}, doi = {10.1186/1742-4690-8-S1-A228}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142248}, pages = {A228}, year = {2011}, abstract = {No abstract available.}, language = {en} } @article{KasangKalluvyaMajingeetal.2011, author = {Kasang, Christa and Kalluvya, Samuel and Majinge, Charles and Stich, August and Bodem, Jochen and Kongola, Gilbert and Jacobs, Graeme B. and Mllewa, Mathias and Mildner, Miriam and Hensel, Irina and Horn, Anne and Preiser, Wolfgang and van Zyl, Gert and Klinker, Hartwig and Koutsilieri, Eleni and Rethwilm, Axel and Scheller, Carsten and Weissbrich, Benedikt}, title = {HIV drug resistance (HIVDR) in antiretroviral therapy-naive patients in Tanzania not eligible for WHO threshold HIVDR survey is dramatically high}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69024}, year = {2011}, abstract = {Background: The World Health Organization (WHO) has recommended guidelines for a HIV drug resistance (HIVDR) survey for resource-limited countries. Eligibility criteria for patients include age below 25 years in order to focus on the prevalence of transmitted HIVDR (tHIVDR) in newly-infected individuals. Most of the participating sites across Africa have so far reported tHIVDR prevalences of below 5\%. In this study we investigated whether the rate of HIVDR in patients ,25 years is representative for HIVDR in the rest of the therapy-naive population. Methods and Findings: HIVDR was determined in 88 sequentially enrolled ART-naive patients from Mwanza, Tanzania (mean age 35.4 years). Twenty patients were aged, 25 years and 68 patients were aged 25-63 years. The frequency of HIVDR in the study population was 14.8\% (95\%; CI 0.072-0.223) and independent of NVP-resistance induced by prevention of mother-to-child transmission programs. Patients .25 years had a significantly higher HIVDR frequency than younger patients (19.1\%; 95\% CI 0.095-0.28) versus 0\%, P = 0.0344). In 2 out of the 16 patients with HIVDR we found traces of antiretrovirals (ARVs) in plasma. Conclusions: ART-naive patients aged over 25 years exhibited significantly higher HIVDR than younger patients. Detection of traces of ARVs in individuals with HIVDR suggests that besides transmission, undisclosed misuse of ARVs may constitute a significant factor in the generation of the observed high HIVDR rate. The current WHO tHIVDR survey that is solely focused on the transmission of HIVDR and that excludes patients over 25 years of age may therefore result in substantial underestimation of the prevalence of HIVDR in the therapy-naive population. Similar studies should be performed also in other areas to test whether the so far reported optimistic picture of low HIVDR prevalence in young individuals is really representative for the rest of the ART-naive HIV-infected population.}, subject = {Tansania}, language = {en} } @article{LindemannRethwilm2011, author = {Lindemann, Dirk and Rethwilm, Axel}, title = {Foamy Virus Biology and Its Application for Vector Development}, series = {Viruses}, volume = {3}, journal = {Viruses}, number = {5}, doi = {10.3390/v3050561}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-139811}, pages = {561-585}, year = {2011}, abstract = {Spuma- or foamy viruses (FV), endemic in most non-human primates, cats, cattle and horses, comprise a special type of retrovirus that has developed a replication strategy combining features of both retroviruses and hepadnaviruses. Unique features of FVs include an apparent apathogenicity in natural hosts as well as zoonotically infected humans, a reverse transcription of the packaged viral RNA genome late during viral replication resulting in an infectious DNA genome in released FV particles and a special particle release strategy depending capsid and glycoprotein coexpression and specific interaction between both components. In addition, particular features with respect to the integration profile into the host genomic DNA discriminate FV from orthoretroviruses. It appears that some inherent properties of FV vectors set them favorably apart from orthoretroviral vectors and ask for additional basic research on the viruses as well as on the application in Gene Therapy. This review will summarize the current knowledge of FV biology and the development as a gene transfer system.}, language = {en} } @article{KasangKalluvyaMajingeetal.2011, author = {Kasang, Christa and Kalluvya, Samuel and Majinge, Charles and Stich, August and Bodem, Jochen and Kongola, Gilbert and Jacobs, Graeme B. and Mlewa, Mathias and Mildner, Miriam and Hensel, Irina and Horn, Anne and Preiser, Wolfgang and van Zyl, Gert and Klinker, Hartwig and Koutsilieri, Eleni and Rethwilm, Axel and Scheller, Carsten and Weissbrich, Benedikt}, title = {HIV Drug Resistance (HIVDR) in Antiretroviral Therapy-Na{\"i}ve Patients in Tanzania Not Eligible for WHO Threshold HIVDR Survey Is Dramatically High}, series = {PLoS One}, volume = {6}, journal = {PLoS One}, number = {8}, doi = {10.1371/journal.pone.0023091}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137988}, pages = {e23091}, year = {2011}, abstract = {Background The World Health Organization (WHO) has recommended guidelines for a HIV drug resistance (HIVDR) survey for resource-limited countries. Eligibility criteria for patients include age below 25 years in order to focus on the prevalence of transmitted HIVDR (tHIVDR) in newly-infected individuals. Most of the participating sites across Africa have so far reported tHIVDR prevalences of below 5\%. In this study we investigated whether the rate of HIVDR in patients <25 years is representative for HIVDR in the rest of the therapy-na{\"i}ve population. Methods and Findings HIVDR was determined in 88 sequentially enrolled ART-na{\"i}ve patients from Mwanza, Tanzania (mean age 35.4 years). Twenty patients were aged <25 years and 68 patients were aged 25-63 years. The frequency of HIVDR in the study population was 14.8\% (95\%; CI 0.072-0.223) and independent of NVP-resistance induced by prevention of mother-to-child transmission programs. Patients >25 years had a significantly higher HIVDR frequency than younger patients (19.1\%; 95\% CI 0.095-0.28) versus 0\%, P = 0.0344). In 2 out of the 16 patients with HIVDR we found traces of antiretrovirals (ARVs) in plasma. Conclusions ART-na{\"i}ve patients aged over 25 years exhibited significantly higher HIVDR than younger patients. Detection of traces of ARVs in individuals with HIVDR suggests that besides transmission, undisclosed misuse of ARVs may constitute a significant factor in the generation of the observed high HIVDR rate. The current WHO tHIVDR survey that is solely focused on the transmission of HIVDR and that excludes patients over 25 years of age may therefore result in substantial underestimation of the prevalence of HIVDR in the therapy-na{\"i}ve population. Similar studies should be performed also in other areas to test whether the so far reported optimistic picture of low HIVDR prevalence in young individuals is really representative for the rest of the ART-na{\"i}ve HIV-infected population.}, language = {en} } @article{SiwkaSchwinnBaczkoetal.1994, author = {Siwka, Wieslaw and Schwinn, Andreas and Baczko, Knut and Pardowitz, Iancu and Mhalu, Fred and Shao, John and Rethwilm, Axel and ter Meulen, Volker}, title = {vpu and env sequence variability of HIV-1 isolates from Tanzania}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61355}, year = {1994}, abstract = {No abstract available}, subject = {Virologie}, language = {en} } @article{HahnBaunachBraeutigametal.1994, author = {Hahn, Heidi and Baunach, Gerald and Br{\"a}utigam, Sandra and Mergia, Ayalew and Neumann-Haefelin, Dieter and Daniel, Muthiah D. and McClure, Myra O. and Rethwilm, Axel}, title = {Reactivity of primate sera to foamy virus Gag and Bet proteins}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61366}, year = {1994}, abstract = {In order to establish criteria for the Serodiagnosis of foamy virus infections we investigated the extent to which sera from iofected individuals of human and primate origin react with structural and non-structural virus proteins in immunoblot assays. Using lysates from infected cells as the source of virus antigen, antibodies were preferentially detected against the Gag proteins and the non-structural Bet protein. Both the Gag precursor molecules of 70 and 74K apparent M\(_r\) and the cytoplasmic 60K M\(_r\) Bet protein were found to be phosphorylated, the latter being synthesized in large amounts in infected cells. Rahbit antiserum raised against recombinant human foamy virus (HFV) Gag major capsid protein cross-reacted with foamy viruses of chimpanzee, gorilla, orang-utan, rhesus monkey and Mrican green monkey origin. This was reßected by a broad cross-reactivity of the respective monkey sera to the Gag proteins of the various foamy virus isolates. Cross-reactivity of antisera against the Bet protein was restricted to viruses from man and the great apes. Recombinant Gag and Bet proteins expressed in prokaryotes or in insect cells were readily recognized by foamy virus-positive primate sera. Screening serum samples from chimpanzees with HFV Gag and Bet proteins expressed by recombinant baculoviruses revealed that 18 out of 35 (52\%) were positive for Gag antibodies. Of these, 13 (72 o/o) showed antiborlies against the Bet protein, indicating that Bet antigen is of value in sero1ogical screening for foamy virus infections.}, subject = {Virologie}, language = {en} } @article{SchliephakeRethwilm1994, author = {Schliephake, Andreas W. and Rethwilm, Axel}, title = {Nuclear Localization of Foamy Virus Gag Precursor Protein}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61371}, year = {1994}, abstract = {All foamy viruses give rise to a strong nuclear staining when infected cells are reacted with sera from infected hosts. This nuclear ftuorescence distinguishes foamy viruses from all other retroviruses. The experiments reported here indicate that the foamy virus Gag precursor protein is transiently located in the nuclei of infected cells and this is the likely reason for the typical foamy virus nuclear fluorescence. By using the vaccinia virus expression system, a conserved basic sequence motif in the nucleocapsid domain of foamy virus Cag proteins was identified to be responsible for the nuclear transport of the gag precursor molecule. Tbis motif was also found to be able to direct a heterologous protein, the Gag protein of human immunodeficiency virus, into the nucleus.}, subject = {Virologie}, language = {en} } @article{AguzziWagnerNetzeretal.1993, author = {Aguzzi, A. and Wagner, E. F. and Netzer, K. O. and Bothe, K. and Anhauser, I. and Rethwilm, Axel}, title = {Human foamy virus proteins accumulate in neurons and induce multinucleated giant cells in the brain of transgenic mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47356}, year = {1993}, abstract = {Humanfoamy virus (HFV) is a retrovirus encoding structural genes and, like human immunodeficiency virus and human T ceU leukemia virus I, several anciUary reading frames collectively termed the belgenes. We have previously shown that HFV transgenic mice develop an encephalopathy with neuronal loss in hippocampus and cerebral cortex. We have now raised and characterized rabbit antisera to various recombinant portions of gag, pot, env, and bel-I, the viraltransactivator. Immunoreactivity for gag and bel-I was observed in nuclei and processes of hippocampal and cortical neurons before the onset of morphological lesions and correlated with the appearance of HFV mRNA. Astrocyte-derived multinucleated giant ceUs containing HFV proteins were present in the brain oftransgenic mice coexpressingfuU- length HFV genes but not in mice expressing truncated gag and env, suggesting that these genes contain afusogenic domain. Expression of fuU-length structural genes decreased the life expectancy oftransgenic mice, implying an a4Juvant rolefor these proteins in HFV-induced brain damage. (Am] Pathol 1993, 142:1061-1072)}, subject = {Molekularpathologie}, language = {en} } @article{HongBraeutigamRethwilm1993, author = {Hong, Liu and Br{\"a}utigam, Sandra and Rethwilm, Axel}, title = {Expression of the human foamy virus bel-1 transactivator in insect cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61383}, year = {1993}, abstract = {The human foamy virus (HFV) bel-l transactivator protein was expressed in insect cells by a recombinant baculovirus. For the generation of the recombinant baculovirus, Acbel-1, the bel-l gene of an HFV mutant was used, that bears truncations in the bel-l overlapping bel-2 open reading frame. Acbel-1 infected Sf9 cells produced high amounts of recombinant protein of the same electrophoretic mobility (36 kD) as bel-l expressed in mammalian cells. The baculovirus expressed bel-l proteinwas readily identified by a polyclonal rabbit serum directed against bel-1 in immunoblot assay. As in mammalian cells, bel-l was predominantly localized to the nucleus of Acbel-1 infected insect cells. The baculovirus expressed bel-1 proteinwill be of use to determine the action of this novel viral transactivator more precisely.}, subject = {Virologie}, language = {en} } @article{BaunachMaurerHahnetal.1993, author = {Baunach, Gerald and Maurer, Bernd and Hahn, Heidi and Kranz, Manuela and Rethwilm, Axel}, title = {Functional analysis of human foamy virus accessory reading frames}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61398}, year = {1993}, abstract = {No abstract available}, subject = {Virologie}, language = {en} } @article{ErlweinRethwilm1993, author = {Erlwein, Otto and Rethwilm, Axel}, title = {BEL-1 transactivator responsive sequences in the long terminal repeat of human foamy virus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61402}, year = {1993}, abstract = {No abstract available}, subject = {Virologie}, language = {en} } @article{BrinkmannSchwinnMuelleretal.1993, author = {Brinkmann, R. and Schwinn, A. and M{\"u}ller, J. and Stahl-Hennig, C. and Coulibaly, C. and Hunsmann, G. and Czub, S. and Rethwilm, Axel and D{\"o}rries, R. and ter Meulen, Volker}, title = {In vitro and in vivo infection of rhesus monkey microglial cells by simian immunodeficiency virus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61415}, year = {1993}, abstract = {The observation that microglial cells in brain tissue are probably a major target for human immunodeficiency virus (HIV) infection has raised interest in the pathogenic role of this cell population for the development of neuro-AIOS. Since it is very difficult to obtain microglia from normal or diseased human brain we studied microglial cells isolated from fresh brain tissue of uninfected and simian immunodeficiency virus (SIV) infected rhesus monkeys (Macacca mulatta) in comparison to peripheral blood macrophages. Besides the characterization of the phenotypes of these two cell populations, we examined the replication of SIV in the cells in addition to the effect of viral infection on the expression of cell surface molecules. We found that microglia and macrophages support replication of the wild-type SIV\(_{mac25}\), strain as well as the infectious clone (SIV\(_239\)). Infectious viruswas produced and a CPE developed. Isolated microglial cells from SIV-infected monkeys were latently infected independent of the presence of neuropathological lesions and produced infectious virus after 20-25 days in culture. In situ hybridization revealed that only a small percentage of isolated microglial cells are productively infected in vivo, yet the majority of these expressed MHC class II molecules. This indicated a state of activation that is acquired in vivo. These findings indicate that microglia are a prime target cell for SIV infection in CNS tissue.}, subject = {Virologie}, language = {en} } @article{NetzerSchliephakeMaureretal.1993, author = {Netzer, Kai O. and Schliephake, Andreas and Maurer, Bernd and Watanabe, Rihito and Aguzzi, Adriano and Rethwilm, Axel}, title = {Identification of pol-related gene products of human foamy virus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61429}, year = {1993}, abstract = {Human foamy viruspol gene fragments were molecularly cloned into a procaryotic expression vector. The expression pattern of the cloned fragments and nucleotide sequence analysis of the 5' pol gene region revealed that in HFV the protease (PR) is located in the pol open reading frame. Purified recombinant proteins were used to generate antibodies in rats. ln immunoblot assay, using infected cells as antigen, a precursor protein with an apparent molecular mass (M,) of 127K was identified by antibodies directed against the reverse transcriptase (RT), RNaseH, or integrase (IN) domeins of pol. With concentrated virus as antigen, the RT and RNaseH antibodies recognized a protein of 80K, the IN antiserum recognized a protein of 40K, and the PR antiserum detected a protein of approximately 10K.}, subject = {Virologie}, language = {en} }