scholarly journals Systemic Infection and Limited Replication of SHIV Vaccine Virus in Brains of Macaques Inoculated Intracerebrally with Infectious Viral DNA

Virology ◽  
2002 ◽  
Vol 301 (1) ◽  
pp. 130-135 ◽  
Author(s):  
Marilyn S. Smith ◽  
Yafen Niu ◽  
Zhuang Li ◽  
Istvan Adany ◽  
David M. Pinson ◽  
...  
2015 ◽  
Vol 89 (23) ◽  
pp. 11926-11934 ◽  
Author(s):  
Karin Weigel ◽  
Jens O. Pohl ◽  
Christina Wege ◽  
Holger Jeske

ABSTRACTThe selective accumulation of both DNA components of a bipartite geminivirus,Abutilonmosaic virus, was recorded during early systemic infection ofNicotiana benthamianaplants. Purified nuclei were diagnosed for viral DNA using hybridization specific for DNA A or DNA B to detect these individual genome components either alone or both simultaneously by dual-color staining. Although this virus needs both components for symptomatic infection, DNA A alone was transported to upper leaves, where it was imported into phloem nuclei and replicated autonomously. The coinfection with DNA A and DNA B revealed an independent spread of both molecules, which resulted in a stochastic distribution of DNA A- and DNA A/B-infected nuclei. A population genetics evaluation of the respective frequencies was compared to a model computation. This elucidated a surprisingly simple relationship between the initial frequencies of the viral DNA components and the number of susceptible cells during the course of early systemic infection.IMPORTANCEFor bipartite begomoviruses, DNA B-independent long-distance spread of DNA A has been described before, but it has never been shown whether viral DNA A alone invades nuclei of systemic tissues and replicates therein. This is demonstrated now for the first time. During infection with DNA A and DNA B, a similar solitary spread of DNA A can be recognized at early stages. We describe a population genetics model of how the hit probabilities of DNA A and DNA B for susceptible cells determine the relative frequencies of either genome component during the course of infection.


2001 ◽  
Vol 82 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Huanting Liu ◽  
Margaret I. Boulton ◽  
Karl J. Oparka ◽  
Jeffrey W. Davies

We have shown previously that the movement protein (MP) and coat protein (CP) of Maize streak virus (MSV) are both required for systemic infection. Towards understanding the roles of these two proteins in virus movement, each was expressed in E. coli and interactions of the MP with viral DNA or CP were investigated using south-western, gel overlay and immunoprecipitation assays. Unlike the CP, the MP did not bind to viral DNA but it interacted with the CP in vitro and an MP–CP complex was detected in extracts from MSV-infected maize, indicating the potential for an interaction in vivo. Microinjection showed that the MP could prevent the nuclear transport of an MSV CP–DNA complex in maize and tobacco cells. These results are consistent with a model in which the MP diverts a CP–DNA complex from the nucleus (where viral DNA replication takes place) to the cell periphery, and in co-operation with the CP, mediates the cell-to-cell movement of the viral DNA. In this respect, the MSV MP and CP have functional analogy with the BC1 and BV1 proteins, respectively, of the Begomovirus genus of the Geminiviridae.


2003 ◽  
Vol 77 (5) ◽  
pp. 3099-3118 ◽  
Author(s):  
Kristina Abel ◽  
Lara Compton ◽  
Tracy Rourke ◽  
David Montefiori ◽  
Ding Lu ◽  
...  

ABSTRACT Attenuated primate lentivirus vaccines provide the most consistent protection against challenge with pathogenic simian immunodeficiency virus (SIV). Thus, they provide an excellent model to examine the influence of the route of immunization on challenge outcome and to study vaccine-induced protective anti-SIV immune responses. In the present study, rhesus macaques were immunized with live nonpathogenic simian-human immunodeficiency virus (SHIV) 89.6 either intravenously or mucosally (intranasally or intravaginally) and then challenged intravaginally with pathogenic SIVmac239. The route of immunization did not affect mucosal challenge outcome after a prolonged period of systemic infection with the nonpathogenic vaccine virus. Further, protection from the SIV challenge was associated with the induction of multiple host immune effector mechanisms. A comparison of immune responses in vaccinated-protected and vaccinated-unprotected animals revealed that vaccinated-protected animals had higher frequencies of SIV Gag-specific cytotoxic T lymphocytes and gamma interferon (IFN-γ)-secreting cells during the acute phase postchallenge. Vaccinated-protected animals also had a more pronounced increase in peripheral blood mononuclear cell IFN-α mRNA levels than did the vaccinated-unprotected animals in the first few weeks after challenge. Thus, innate as well as cellular anti-SIV immune responses appeared to contribute to the SHIV89.6-induced protection against intravaginal challenge with pathogenic SIVmac239.


2004 ◽  
Vol 94 (7) ◽  
pp. 772-779 ◽  
Author(s):  
Surendranath Baliji ◽  
Mark C. Black ◽  
Roy French ◽  
Drake C. Stenger ◽  
Garry Sunter

A curtovirus associated with a disease of spinach was isolated in southwest Texas during 1996. Disease symptoms included severe stunting and chlorosis, with younger leaves curled, distorted, and dwarfed. Viral DNA was purified and an infectious clone obtained. Agroinoculation using a construct bearing full-length tandem repeats of the cloned viral genome resulted in systemic infection of species in six of seven plant families tested, indicating that the virus has a wide host range. Symptoms produced in spinach agroinoculated with cloned viral DNA were similar to those observed in the field. Viral single-stranded and double-stranded DNA forms typical of curtovirus infection were detected in host plants by Southern blot hybridization. The complete sequence of the infectious clone comprised 2,925 nucleotides, with seven open reading frames encoding proteins homologous to those of other curtoviruses. Complete genome comparisons revealed that the spinach curtovirus shared 64.2 to 83.9% nucleotide sequence identity relative to four previously characterized curtovirus species: Beet curly top virus, Beet severe curly top virus, Beet mild curly top virus, and Horseradish curly top virus. Phylogenetic analysis of individual open reading frames indicated that the evolutionary history of the three virion-sense genes was different from that of the four complementary-sense genes, suggesting that recombination among curtoviruses may have occurred. Collectively, these results indicate that the spinach curtovirus characterized here represents a newly described species of the genus Curtovirus, for which we propose the name Spinach curly top virus.


Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1244
Author(s):  
Angélica M. Nogueira ◽  
Monique B. Nascimento ◽  
Tarsiane M. C. Barbosa ◽  
Ayane F. F. Quadros ◽  
João Paulo A. Gomes ◽  
...  

Begomoviruses can be found in association with alphasatellites, which are capable of autonomous replication but are dependent on the helper begomovirus for systemic infection, encapsidation and vector transmission. Previous studies suggest that the presence of NW alphasatellites (genus Clecrusatellite) is associated with more severe symptoms. To better understand this interaction, we investigated the effects of two alphasatellites on infectivity, symptom development, viral DNA accumulation and vector transmission of three begomoviruses in three hosts. In tomato and Nicotiana benthamiana, all combinations were infectious. In Leonurus sibiricus, only the ToYSV/ToYSA combination was infectious. The presence of EuYMA increased symptom severity of EuYMV and ToYSV in N. benthamiana, and the presence of ToYSA was associated with more severe symptoms of ToYSV in N. benthamiana and L. sibiricus. EuYMA increased the accumulation of ToYSV in N. benthamiana but reduced the accumulation of EuYMV in tomato and of ToSRV in N. benthamiana. The presence of ToYSA decreased the accumulation of ToYSV in N. benthamiana and L. sibiricus. ToYSA negatively affected transmission of ToSRV by Bemisia tabaci MEAM1. Together, our results indicate that NW alphasatellites can interact with different begomoviruses, increasing symptom severity and interfering in the transmission of the helper begomovirus. Understanding this interaction is important as it may affect the emergence of diseases caused by begomovirus–alphasatellite complexes in the field.


Author(s):  
Dwight Anderson ◽  
Charlene Peterson ◽  
Gursaran Notani ◽  
Bernard Reilly

The protein product of cistron 3 of Bacillus subtilis bacteriophage Ø29 is essential for viral DNA synthesis and is covalently bound to the 5’-termini of the Ø29 DNA. When the DNA-protein complex is cleaved with a restriction endonuclease, the protein is bound to the two terminal fragments. The 28,000 dalton protein can be visualized by electron microscopy as a small dot and often is seen only when two ends are in apposition as in multimers or in glutaraldehyde-fixed aggregates. We sought to improve the visibility of these small proteins by use of antibody labeling.


2010 ◽  
Vol 34 (8) ◽  
pp. S60-S60
Author(s):  
Yuning Sun ◽  
Fang Li ◽  
Jianming Qiu ◽  
Xiaohong Lu

2020 ◽  
Vol 5 (3) ◽  
pp. 1191-1195
Author(s):  
Sushmita Shrestha ◽  
Navin Agrawal ◽  
Deependra Prasad Sarraf

Introduction: Irrational or inappropriate prescribing practice is common in developing countries that can lead to ineffective treatment, prolonged hospitalization, harm to the patient, increased treatment cost and development of drug-resistant organisms. The prescription of antibiotics and other drugs in endodontics is limited to patients with progressive and diffuse swelling and with systemic infection. However, antibiotics continue to be over-prescribed by more than 66% dentists without a rational justification.Therefore, the periodic assessment of drug utilization pattern is important to know the existing pattern of drug use, decrease adverse effects and provide feedback to the prescribers. Objective: To evaluate the drug utilization pattern in endodontics using the World Health Organization prescribing indicators. Methodology: A cross-sectional prospective study was conducted among the patients visiting the outpatient department of Conservative Dentistry and Endodontics. After obtaining the informed consent, the relevant data were collected on a self-designed proforma by reviewing the health cards of the patients. The WHO prescribing indicators were calculated. Descriptive statistics were calculated using SPSS version 11.0. Results: Out of 187 patients, 101 (54%) were female. Mean age was 38.9±16.6 years. Majority of the patients suffered from acute apical periodontitis (30.5%). A total of 281 drugs were prescribed to 187 patients. Paracetamol+Ibuprofen (44.1%) was the most frequently prescribed drugs. Most of the patients were prescribed one drug (78.6%).  Average drug per prescription was 1.5. Majority of the drugs (89.0%) were prescribed from Essential drug list of Nepal. Conclusions: Analgesics were the most frequently prescribed drug. The prescription practice was rational. There is need to increase the number of medicine prescribed from National List of Essential medicines.Educational initiatives should be undertaken to further strengthen the rational prescription among dental practitioners.


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