Project description:Classically, the cytidine deaminase APOBEC3G (A3G) exerts antiviral activity against transposable elements, retroviruses, and hepatitis B virus. However, we found earlier, that it also inhibits measles (MV), mumps (MuV) and respiratory syncytial virus (RSV), but the mechanism of inhibition remained unclear. Because A3G is present in RNA processing (P) bodies, where it is involved in the regulation of mRNA decay, we supposed that it may influence the expression of host cell factors, some of which may affect viral replication. Using a microarray we therefore assessed in Vero cells whether A3G expression influences the cellular gene expression. We found alterations indicating 844 up-regulated and 598 down-regulated transcripts (adjusted P values < 0.05). Of these trancripts 19 were up-regulated and 23 down-regulated by a factor of > 2. One of the down-regulated factors, MOSC2, appeared to support MV replication, since shRNA-mediated MOSC2 knock down reduced MV replication. In addition, two up-regulated factors, REDD1 and KDELR2, impaired MV replication when over-expressed in VeroREDD1 is a cellular inhibitor of mTORC1, a regulator of cellular homeostasis controlling cell growth and protein synthesis. Rapamycin also reduced MV replication confirming our findings with REDD1. The KDELR2 retains chaperons in the ER, which are required for proper folding and transport of MV glycoproteins to the cell surface, and thereby reduces MV glycoprotein expression at the cell surface, syncytium formation, and the formation of infectious virus.
Project description:In contrast to SIVagm, which does not cause disease in its natural simian host, HIV-1 expresses the accessory protein Vpu and encodes a Nef protein that fails to suppress T cell activation via down-modulation of CD3. Although both, Vpu and Nef have been implicated as pathogenicity determinants, their relevance for viral replication and disease progression in vivo has remained unclear. Here, we analyzed gene expression in African green monkeys infected with SIVagm chimeras differing in their expression of nef and/or vpu. We used microarrays to analyze global gene expression of African green monkeys in response to infection with SIVagm and found that the viral accessory nef and vpu genes co-determine the induction of distinct gene sets.
Project description:We describe a genome reference of the African green monkey or vervet (Chlorocebus aethiops). This member of the Old World monkey (OWM) superfamily is uniquely valuable for genetic investigations of simian immunodeficiency virus (SIV), for which it is the most abundant natural host species, and of a wide range of health-related phenotypes assessed in Caribbean vervets (C. a. sabaeus), whose numbers have expanded dramatically since Europeans introduced small numbers of their ancestors from West Africa during the colonial era. We use the reference to characterize the genomic relationship between vervets and other primates, the intra-generic phylogeny of vervet subspecies, and genome-wide structural variations of a pedigreed C. a. sabaeus population. Through comparative analyses with human and rhesus macaque, we characterize at high resolution the unique chromosomal fission events that differentiate the vervets and their close relatives from most other catarrhine primates, in whom karyotype is highly conserved. We also provide a summary of transposable elements and contrast these with the rhesus macaque and human. Analysis of sequenced genomes representing each of the main vervet subspecies supports previously hypothesized relationships between these populations, which range across most of sub-Saharan Africa, while uncovering high levels of genetic diversity within each. Sequence-based analyses of major histocompatibility complex (MHC) polymorphisms reveal extremely low diversity in Caribbean C. a. sabaeus vervets, compared to vervets from putatively ancestral West African regions. In the C. a. sabaeus research population, we discover the first structural variations that are, in some cases, predicted to have a deleterious effect; future studies will determine the phenotypic impact of these variations.
Project description:Full-field electroretinography is an objective measure of retinal function, serving as an important diagnostic clinical tool in ophthalmology for evaluating the integrity of the retina. Given the similarity between the anatomy and physiology of the human and Green Monkey eyes, this species has increasingly become a favorable non-human primate model for assessing ocular defects in humans. To test this model, we obtained full-field electroretinographic recordings (ERG) and normal values for standard responses required by the International Society for Clinical Electrophysiology of Vision (ISCEV). Photopic and scotopic ERG recordings were obtained by full-field stimulation over a range of 6 log units of intensity in dark-adapted or light-adapted eyes of adult Green Monkeys (Chlorocebus sabaeus). Intensity, duration, and interval of light stimuli were varied separately. Reproducible values of amplitude and latency were obtained for the a- and b-waves, under well-controlled adaptation and stimulus conditions; the i-wave was also easily identifiable and separated from the a-b-wave complex in the photopic ERG. The recordings obtained in the healthy Green Monkey matched very well with those in humans and other non-human primate species (Macaca mulatta and Macaca fascicularis). These results validate the Green Monkey as an excellent non-human primate model, with potential to serve for testing retinal function following various manipulations such as visual deprivation or drug evaluation.
Project description:Two rounds of TMT relative quantitative proteomics were performed to detect cellular factors involved in p-eIF4E regulation of the synthesis of viral proteins.our first round of screening identified differentially expressed proteins in PEDV-infected cells and mock-infected cells; the cellular pathways involved were mainly the estrogen, cAMP, and calcium signaling pathways. Second round screening identified differentially expressed proteins in the PEDV-infected S209A-Vero cells vs. the PEDV-infected WT-Vero cells; the regulated cellular pathways were found to be mainly in the PI3K-Akt, focal adhesion, and mTOR signaling pathways, and the biological processes and molecular functions in which p-eIF4E played a role were related mainly to metabolism and biogenesis, catalytic activity, and stimuli response.4006 host factors were detected, of which 193 (in brown) were significantly upregulated (ratio ≥1.2, P<0.05) and 191 (in green) were down-regulated upon PEDV infection (ratio ≤0.83, P<0.05). 29 of the 191 down-regulated proteins were susceptible to a low level of p-eIF4E . Notably, among the 193 upregulated cellular proteins, 77 were upregulated in the WT-Vero over the S209A-Vero cells , suggesting that the WT-Vero cells are more susceptible to a high level of p-eIF4E.