TASK DEFINITION: In this task, you're given a paragraph and title from the research paper. Your task is to classify whether the given title is suitable or not for the research paper based on the given paragraph. Return "True" if title is proper according to paragraph else "False".
PROBLEM: Paragraph: The simian hemorrhagic fever virus (SHFV) genome differs from those of other members of the family Arteriviridae in encoding three papain-like one proteases (PLP1, PLP1 and PLP1) at the 5 end and two adjacent sets of four minor structural proteins at the 3 end. The catalytic Cys and His residues and cleavage sites for each of the SHFV PLP1s were predicted and their functionality was tested in in vitro transcription/translation reactions done with wildtype or mutant polyprotein constructs. Mass spectrometry analyses of selected autoproteolytic products confirmed cleavage site locations. The catalytic Cys of PLP1 is unusual in being adjacent to an Ala instead of a Typ. PLP1 cleaves at both downstream and upstream sites. Intermediate precursor and alternative cleavage products were detected in the in vitro transcription/translation reactions but only the three mature nsp1 proteins were detected in SHFV-infected MA104 cell lysates with SHFV nsp1 protein-specific antibodies. The duplicated sets of SHFV minor structural proteins were predicted to be functionally redundant. A stable, full-length, infectious SHFV-LVR cDNA clone was constructed and a set of mutant infectious clones was generated each with the start codon of one of the minor structural proteins mutated. All eight of the minor structural proteins were found to be required for production of infectious extracellular virus. SHFV causes a fatal hemorrhagic fever in macaques but asymptomatic, persistent infections in natural hosts such as baboons. SHFV infections were compared in macrophages and myeloid dendritic cells from baboons and macaques. Virus yields were higher from macaque cells than from baboon cells. Macrophage cultures from the two types of animals differed dramatically in the percentage of cells infected. In contrast, similar percentages of myeloid dendritic cells were infected but virus replication was efficient in the macaque cells but inefficient in the baboon cells. SHFV infection induced the production of pro-inflammatory cytokines, including IL-1, IL-6, IL-12/23(p40), TNF- and MIP-1, in macaque cells but not baboon cells. (M.A. Brinton). capsid types (coronaviruses-helical and arteriviruses-spherical) and virion sizes. Arteriviruses infect macrophages (M s) and dendritic cells (DCs) and have restricted host ranges; EAV infects horses and donkeys, PRRSV infects pigs, LDV infects mice and SHFV infects nonhuman primates (NHPs) (Snijder and Meulenberg, 1998) . Disease symptoms associated with EAV and PRRSV infections include fever, respiratory disease, tissue necrosis and spontaneous abortions while LDV typically causes an asymptomatic, persistent infection (Snijder and Spaan, 2006) . The majority of research on arteriviruses has focused on EAV and PRRSV due to the significant agricultural impact of the diseases they cause. SHFV was first isolated in 1964 as the causative agent of hemorrhagic fever outbreaks associated with high mortality in macaque colonies in the United States and the USSR http://dx.
Title: Simian hemorrhagic fever virus: Recent advances

SOLUTION: True

PROBLEM: Paragraph: The ability of emerging pathogens to infect new species is likely related to the diversity of pathogen variants present in existing reservoirs and their degree of genomic plasticity, which determines their ability to adapt to new environments. Certain simian immunodeficiency viruses (SIVcpz, SIVsm) have demonstrated tremendous success in infecting new species, including humans, resulting in the HIV-1 and HIV-2 epidemics. Although SIV diversification has been studied on a population level, the essential substrates for cross-species transmission, namely SIV sequence diversity and the types and extent of viral diversification present in individual reservoir animals have not been elucidated. To characterize this intra-host SIV diversity, we performed sequence analyses of clonal viral envelope (env) V1V2 and gag p27 variants present in individual SIVsm-infected sooty mangabeys over time. Results: SIVsm demonstrated extensive intra-animal V1V2 length variation and amino acid diversity (le38%), and continual variation in V1V2 N-linked glycosylation consensus sequence frequency and location. Positive selection was the predominant evolutionary force. Temporal sequence shifts suggested continual selection, likely due to evolving antibody responses. In contrast, gag p27 was predominantly under purifying selection. SIVsm V1V2 sequence diversification is at least as great as that in HIV-1 infected humans, indicating that extensive viral diversification in and of itself does not inevitably lead to AIDS. Positive diversifying selection in this natural reservoir host is the engine that has driven the evolution of the uniquely adaptable SIV/HIV envelope protein. These studies emphasize the importance of retroviral diversification within individual host reservoir animals as a critical substrate in facilitating cross-species transmission.
Title: Evolution of the uniquely adaptable lentiviral envelope in a natural reservoir host

SOLUTION: False

PROBLEM: Paragraph: Viruses are dependent on the cellular translation machinery for protein synthesis. Part of the innate immune response to infection is activation of the stress kinase PKR which phosphorylates the alpha subunit of the initiation factor eIF2. This results in inhibition of translation and is intended to block virus replication. A downstream effect of translational shutoff involves the formation of cytoplasmic granules, termed stress granules (SGs), that contain mRNAs, initiation factors, ribosomal subunits, and other mRNA regulatory proteins. SGs hold mRNAs in a translationally inactive state until cells recover from stress. Recent studies have begun to elucidate the impact of SGs on virus replication. Not surprisingly, viruses from diverse families have been found to modulate SG formation in infected cells by associating with important SG effecter proteins. This review describes the current knowledge on SGs and their interaction with and impact on virus replication. The most highly regulated stage of protein synthesis occurs at the initiation step. The translation initation factor eIF2 plays a crucial role in this process. In non-stressed cells, eIF2 complexed with GDP associates with eIF2B, a nucleotide exchange factor, which exchanges GDP for GTP. This exchange allows the eIF2:GTP complex to associate with initiator methionine tRNA to form ternary complex (eIF2:GTP:tRNA Met ). Ternary complex brings the initiating methionine to the 43S ribosome pre-initiation complex. The 43S complex contains the 40S ribosome and a variety of additional initiation factors that play important roles in translation. The 43S complex then forms the 48S ribosomal complex by binding mRNA, which has itself been activated for translation via association with additional initiation factors. The 60S ribosomal subunit is then recruited, at which point GTP is hydrolyzed to GDP and eIF2:GDP is released from the ribosomal complex to again associate with eIF2B and be recharged with GTP to start the process anew [reviewed in [1, 2] ]. Following cellular stress, the alpha subunit of eIF2 is phosphorylated by one of four stress activated kinases; GCN, which is activated during nutrient starvation, PERK, which is activated following ER stress, HRI, which is activated following oxidative stress and heme deficiency, and PKR, which is activated following virus infection [reviewed in [3] ].
Title: Stress Granules and Virus Replication HHS Public Access

SOLUTION:
False