A Predictive Network-Based Immune Checkpoint Blockade Immunotherapeutic Signature Optimizing Patient Selection and Treatment Strategies.

Immune checkpoint blockade (ICB) therapy has brought significant advancements to the field of oncology. However, the diverse responses among patients highlight the need for more accurate predictive tools. In this study, insights are drawn from tumor-immunology pathways, and a novel network-based ICB immunotherapeutic signature, termed ICBnetIS, is constructed. The signature is derived from advanced biological network-based computational strategies involving co-expression networks and molecular interactions networks. The efficacy of ICBnetIS is established through its association with enhanced patient survival and a robust immune response characterized by diverse immune cell infiltration and active anti-tumor immune pathways. The validation process positions ICBnetIS as an effective tool in predicting responses to ICB therapy, analyzing ICB data from a broad collection of over 700 samples from multiple cancer types of more than 15 datasets. It achieves an aggregated prediction AUC of 0.784, which outperforms the other nine renowned immunotherapeutic signatures, indicating the superior predictive capability of ICBnetIS. To sum up, the findings suggest ICBnetIS as a potent tool in predicting ICB therapy responses, offering significant implications for patient selection and treatment optimization in oncology. The study highlights the role of ICBnetIS in advancing personalized treatment strategies, potentially transforming the clinical landscape of ICB therapy.

Genetic characteristics of a novel HIV-1 circulating recombinant form (CRF128_07B) identified among MSM in Guangdong Province, China.

OBJECTIVE: To obtain and investigate the genetic characteristics of four HIV-1 near full-length genome sequences (NFLGs), aiming at a description of a novel circulating recombinant form (CRF) in Guangdong China. METHODS: Plasma samples were collected from HIV-1 infected MSM patients in Guangdong Province who had no epidemiological association with each other. The NFLGs were amplified with two overlapping halves and phylogenetic analyses were performed using Mega V11.0.1. Recombination analyses were comprehensively screened with the jpHMM, RIP, and BootScan analyses. Finally, the Bayesian phylogenetic analyses were performed using Beast V1.10.4 to estimate the origin time. RESULTS: Phylogenetic analyses revealed the four NFLGs formed a distinct monophyletic cluster distinguished from other known subtypes in the Neighbor-joining tree. Recombinant analyses revealed they shared a highly similar recombinant pattern, with the CRF07_BC backbone substituted by three subtype B segments. Subregion phylogenetic analyses confirmed them to be a novel CRF composed of CRF07_BC and subtype B, therefore, designed as CRF128_07B. According to the Bayesian phylogenetic analyses, CRF128_07B was inferred to approximately originated around 2005-2006. CONCLUSIONS: These findings described a novel HIV-1 CRF identified from MSM in Guangdong Province. This is the first detection of a CRF comprising CRF07_BC and subtype B. The present finding highlights the urgent need for continuous molecular screening and the epidemic surveillance within the MSM populations.

Environmental gradients shape microbiome assembly and stability in the East China sea.

Microbiomes play a key role in marine ecosystem functioning and sustainability. Their organization and stability in coastal areas, particularly in anthropogenic-influenced regions, however, remains unclear compared with an understanding of how microbial community shifts respond to marine environmental gradients. Here, the assembly and community associations across vertical and horizontal gradients in the East China Sea are systematically researched. The seawater microbial communities possessed higher robustness and lower fragmentation and vulnerability compared to the sediment microbiomes. Spatial gradients act as a deterministic filtering factor for microbiome organization. Microbial communities had lower phylogenetic distance and higher niche breadth in the nearshore and offshore areas compared to intermediate areas. The phylogenetic distance of microbiomes decreased from the surface to the bottom but the niche breadth was enhanced in surface and bottom environments. Vertical gradients destabilized microbial associations, while the community diversity was enhanced. Multivariate regression tree analysis and canonical correspondence analysis indicated that depth, distance from shore, nutrient availability, temperature, salinity, and chlorophyll a, affected the distribution and co-occurrence of microbial groups. Our results highlight the crucial roles of environmental gradients in determining microbiome association and stability. These results improve our understanding of the survival strategies/adaptive mechanisms of microbial communities in response to environmental variation and provide new insights for protecting the ecosystems and maintaining the sustainability of ecological functions.

HIV-1 tropism in low-level viral load HIV-1 infections during HAART in Guangdong, China.

Background: Since only a few studies have been conducted on the factors associated with different HIV-1 tropisms in low-level viral load HIV-1 infections in China, we investigated the sequences of HIV-1 V3 loop in prevalent HIV-1 subtypes and factors related to HIV-1 tropism and immune recovery in HIV-1 infections after 6 months of highly active antiretroviral therapy (HAART) in Guangdong, China. Methods: Plasma samples with HIV-1 RNA of 400-999 copies/mL were collected. We analyzed the amino acid sequence of the V3 loop by in silico prediction algorithms. Mann-Whitney and Chi-square tests were used for statistical comparison. Furthermore, logistic regression and multiple linear regression were used, respectively, for factors associated with 351 HIV-1 tropism and immune recovery of 67 cases with continued CD4+ T cell count during HAART. Results: There was a lower percentage of HIV-1 R5-tropic virus in CRF01_AE (66.3%) (p < 0.0001) and CRF55_01B (52.6%) (p < 0.0001) compared with both CRF07_BC (96.1%) and CRF08_BC (97.4%), respectively. Compared with the R5-tropic virus, higher proportions of IIe8/Val8, Arg11/Lys11, and Arg18/His18/Lys18 were observed in the X4-tropic virus of CRF01_AE and CRF07_BC (p < 0.0001). The baseline CD4+ T cell count (p < 0.0001) and baseline CD4+ T/CD8+ T ratio (p = 0.0006) of all R5-tropic infections were higher than those in the X4-tropic infection. The baseline CD4+ T cell count (odds ratio [OR] 0.9963, p = 0.0097), CRF07_BC (OR 0.1283, p = 0.0002), and CRF08_BC (OR 0.1124, p = 0.0381) were associated with less HIV-1 X4-tropism. The baseline CD4+ T cell count was a positive factor (p < 0.0001) in the recovery of CD4+ T cell count during HAART. Conclusion: R5-tropism represented the majority in low-level viral load HIV-1 infections receiving HAART for more than 6 months in Guangdong, China. The baseline immune level in the HIV-1 R5-tropic infections was higher than that in the X4-tropic infections. The amino acids of the 8th, 11th, and 18th of the HIV-1 V3 loop were more variable in the X4-tropic HIV-1. CRF01_AE, CRF55_01B, and lower baseline CD4+ T cell count were associated with more HIV-1 X4-tropism. The immune recovery during HAART was positively related to baseline CD4+ T cell count.

(S)-N-Benzyl-1-phenyl-3,4-dihydroisoqunoline-2(1H)-carboxamide Derivatives, Multi-Target Inhibitors of Monoamine Oxidase and Cholinesterase: Design, Synthesis, and Biological Activity.

A series of (S)-1-phenyl-3,4-dihydroisoquinoline-2(1H)-carboxamide derivatives was synthesized and evaluated for inhibitory activity against monoamine oxidase (MAO)-A and-B, acetylcholine esterase (AChE), and butyrylcholine esterase (BChE). Four compounds (2i, 2p, 2t, and 2v) showed good inhibitory activity against both MAO-A and MAO-B, and two compounds (2d and 2j) showed selective inhibitory activity against MAO-A, with IC50 values of 1.38 and 2.48 µM, respectively. None of the compounds showed inhibitory activity against AChE; however, 12 compounds showed inhibitory activity against BChE. None of the active compounds showed cytotoxicity against L929cells. Molecular docking revealed several important interactions between the active analogs and amino acid residues of the protein receptors. This research paves the way for further study aimed at designing MAO and ChE inhibitors for the treatment of depression and neurodegenerative disorders.

Remodeling of H3K9me3 during the pluripotent to totipotent-like state transition.

Multiple chromatin modifiers associated with H3K9me3 play important roles in the transition from embryonic stem cells to 2-cell (2C)-like cells. However, it remains elusive how H3K9me3 is remodeled and its association with totipotency. Here, we integrated transcriptome and H3K9me3 profiles to conduct a detailed comparison of 2C embryos and 2C-like cells. Globally, H3K9me3 is highly preserved and H3K9me3 dynamics within the gene locus is not associated with gene expression change during 2C-like transition. Promoter-deposited H3K9me3 plays non-repressive roles in the activation of genes during 2C-like transition. In contrast, transposable elements, residing in the nearby regions of up-regulated genes, undergo extensive elimination of H3K9me3 and are tended to be induced in 2C-like transitions. Furthermore, a large fraction of trophoblast stem cell-specific enhancers undergo loss of H3K9me3 exclusively in MERVL+/Zscan4+ cells. Our study therefore reveals the unique H3K9me3 profiles of 2C-like cells, facilitating the further exploration of totipotency.

The relation between barrier-free environment perception and campus commuting satisfaction.

Introduction: The COVID-19 pandemic, which began in the last quarter of 2019, has had a significant impact on urban transportation. With increasing demand for urban transport, the internal roads and public spaces of university campuses play an important role in facilitating commuting and communication between various functional zones. While considerable research has been conducted on route planning, pedestrian-vehicle segregation, and safety management in the internal transportation environment of university campuses, empirical investigations exploring barrier-free inclusive campus environment design and the subjective evaluation of road and public space users in the aftermath of the COVID-19 pandemic are lacking. Recent developments in travel behavior models and positive psychology have led to an increased focus on the correlation among subjective perceptions, attitudes, emotions, and commuting satisfaction in urban transportation and planning design. Methods: To elucidate this relationship, a study was conducted on the new campus of Central South University in Changsha, Hunan Province, China. Using 312 valid samples, a structural equation model was constructed to analyse the relationship between commuting satisfaction and the barrier-free environment perception of university students regarding the internal transportation environment of the campus. Results: The results revealed that individuals' instantaneous barrier-free environment perceptions and long-term established positive emotions had a significant positive effect on commuting satisfaction. Furthermore, positive emotions were found to mediate the relationship between commuting attitudes induced by COVID-19, barrier-free environment perceptions, and commuting satisfaction. Discussion: The results of this study provide a theoretical basis for the necessity of accessibility design in the post-COVID era. In addition, this study considers the perspective of users to provide ideas for the planning and construction of barrier-free campus environments that are based on convenient and inclusive design.

Highly sensitive analysis of low-molecular-mass aldehydes in beverages using a hydroxylamine reagent by high-performance liquid chromatography with fluorescence detection.

In this study, a fluorescent reagent, 4-((aminooxy)methyl)-7-hydroxycoumarin (AOHC), was for the first time applied to label the low-molecular-mass aldehydes (LMMAs) through reductive oxyamination reaction to afford single N,O-substituted oxyamine derivatives at room temperatures with derivatization efficiencies as high as 96.8%. In the following high-performance liquid chromatography with fluorescence detection analysis, 12 LMMAs, including furfurals, aromatic aldehydes, and aliphatic aldehydes, were baseline-separated on an ODS column and detected with low limits of detection (LODs) (0.2-50 nM), and good precisions (intraday relative standard deviations [RSDs] were 2.40-4.68%, and interday RSDs were 4.65-8.91%). This approach was then adopted to analyze six alcoholic beverages and five dairy products, and nine LMMAs with concentrations in the 0.28-798.16 µM range were successfully detected with excellent accuracies (recoveries were 92.2-106.2%). Finally, the results were statistically analyzed and discussed. The proposed method has several advantages, including high sensitivity, room-temperature labeling, and the avoidance of further extraction and/or enrichment procedures, demonstrating its great utility for monitoring LMMAs in various complex matrices.

Auto-segmentation and time-dependent systematic analysis of mesoscale cellular structure in ß-cells during insulin secretion.

The mesoscale description of the subcellular organization informs about cellular mechanisms in disease state. However, applications of soft X-ray tomography (SXT), an important approach for characterizing organelle organization, are limited by labor-intensive manual segmentation. Here we report a pipeline for automated segmentation and systematic analysis of SXT tomograms. Our approach combines semantic and first-applied instance segmentation to produce separate organelle masks with high Dice and Recall indexes, followed by analysis of organelle localization based on the radial distribution function. We demonstrated this technique by investigating the organization of INS-1E pancreatic ß-cell organization under different treatments at multiple time points. Consistent with a previous analysis of a similar dataset, our results revealed the impact of glucose stimulation on the localization and molecular density of insulin vesicles and mitochondria. This pipeline can be extended to SXT tomograms of any cell type to shed light on the subcellular rearrangements under different drug treatments.

Narrative Scientific Data Visualization in an Immersive Environment.

MOTIVATION: Narrative visualization for scientific data explorations can help users better understand the domain knowledge, because narrative visualizations often present a sequence of facts and observations linked together by a unifying theme or argument. Narrative visualization in immersive environments can provide users with an intuitive experience to interactively explore the scientific data, because immersive environments provide a brand new strategy for interactive scientific data visualization and exploration. However, it is challenging to develop narrative scientific visualization in immersive environments. In this paper, we propose an immersive narrative visualization tool to create and customize scientific data explorations for ordinary users with little knowledge about programming on scientific visualization, They are allowed to define POIs (point of interests) conveniently by the handler of an immersive device. RESULTS: Automatic exploration animations with narrative annotations can be generated by the gradual transitions between consecutive POI pairs. Besides, interactive slicing can be also controlled by device handler. Evaluations including user study and case study are designed and conducted to show the usability and effectiveness of the proposed tool. AVAILABILITY: Related information can be accessed at: https://dabigtou.github.io/richenliu/.

Altered anxiety and social behaviors in a mouse model of Fragile X syndrome treated with hyperbaric oxygen therapy.

Fragile X syndrome (FXS) is a common mental retardation syndrome. Anxiety and abnormal social behaviors are prominent features of FXS in humans. To better understand the effects of hyperbaric oxygen therapy (HBOT) on these behaviors, we analyzed anxiety-related and social behaviors in Fmr1 knockout mice treated by HBOT. In the open field test, HBOT group mice preferred the periphery to central areas and tended to run or walk along the wall. The results suggested that thigmotaxis was significantly increased in the HBOT group compared with the control group. In the elevated plus maze test, the percentage of distance traveled was significantly increased in the open arm and significantly decreased in the closed arm for HBOT group mice compared with control group mice. These results suggested that HBOT group mice displayed enhanced motor activity in the open arm and exhibited fewer anxiety-related behaviors. In the three-chambered social approach test, the HBOT group mice made more approaches to the wire cup containing an acquaintance mouse than control group mice in the sociability test and made more approaches to the wire cup containing a stranger mouse than control group mice in the social novelty preference test. The results suggested that HBOT group mice showed increased levels of social interaction and decreased "social anxiety" than the control group to partner mice in this test. Our findings indicated that HBOT resulted in altered anxiety and social behavior in Fmr1 knockout mice and could possibly be used as a treatment for FXS.

Development of a novel DNA sequencing method not only for hepatitis B virus genotyping but also for drug resistant mutation detection.

BACKGROUND: In HBV-infected patients, different genotypes of the hepatitis B virus influence liver disease progression and response to antiviral therapy. Moreover, long-term antiviral therapy will eventually select for drug-resistant mutants. Detection of mutations associated to antiviral therapy and HBV genotyping are essential for monitoring treatment of chronic hepatitis B patients. RESULTS: In this study, a simple method of partial-S gene sequencing using a common PCR amplification was established for genotyping clinical HBV isolates sensitively, which could detect the drug-resistant mutations successfully at the same time. CONCLUSIONS: The partial S gene sequencing assay developed in this study has potential for application in HBV genotyping and drug resistant mutation detection. It is simpler and more convenient than traditional S gene sequencing, but has nearly the same sensitivity and specificity when compared to S gene sequencing.

The Toll-like receptor adaptor molecule TRIF enhances DNA vaccination against classical swine fever.

To evaluate the effects of the Toll/interleukin-1 receptor domain-containing adaptor-inducing interferon-beta (TRIF) on immune responses induced by DNA vaccines, mice were immunized with the eukaryotic expression plasmid pcDNA/E2 encoding classical swine fever virus (CSFV) E2 alone or in combination with the TRIF genetic adjuvant. Immune responses were examined in immunized mice. Our data demonstrates that co-delivery of the DNA vaccine pcDNA/E2 with the TRIF adjuvant augmented specific humoral and cellular immune responses in a mouse model. Vaccination of pigs confirmed that the pcDNA/E2 in combination with TRIF conferred total protection against lethal challenge with highly virulent CSFV. We conclude that TRIF enhances the effects of the DNA vaccine against CSFV infection and could be used as a potential genetic adjuvant for DNA vaccines in large animal species.

Classical swine fever virus Erns glycoprotein antagonizes induction of interferon-beta by double-stranded RNA.

Classical swine fever virus (CSFV) is capable of counteracting innate cellular antiviral responses by inhibiting type I interferon (IFN)-alpha/beta induction. A function associated with CSFV N(pro), with respect to the inhibition of IFN-beta production, has been clearly elucidated. In this study, we explored the role of CSFV E(rns) in IFN-beta induction by exogenous double-stranded (ds) RNA. Synthetic dsRNA (poly (IC)) was used as an exogenous stimulus to trigger IFN-beta induction. CSFV E(rns) inhibited IFN-beta promoter-driven luciferase activity induced by poly (IC) in different cell lines, and the inhibitory effect was dose-dependent. Moreover, E(rns) reduced IFN-beta mRNA synthesis and blocked IFN-alpha/beta production induced by poly (IC), suggesting that this inhibition occurs at the transcriptional level. Furthermore, E(rns) counteracted poly (IC)-mediated IFN-beta induction independent of its ribonuclease activity. In conclusion, CSFV E(rns) antagonizes extracellular dsRNA-mediated IFN-beta expression. These findings contribute to our understanding of the pathogenesis of CSFV.

Characterization of classical swine fever virus (CSFV) nonstructural protein 3 (NS3) helicase activity and its modulation by CSFV RNA-dependent RNA polymerase.

Classical swine fever virus (CSFV) nonstructural protein 3 (NS3) is believed to possess three enzyme activities that are likely to be essential for virus replication: a serine protease located in the N-terminus and NTPase as well as helicase activities located in the C-terminus. In this report, we expressed NS3 helicase domain (NS3h) in E. coli and characterized its helicase activity. The NS3h helicase activity was dependent on the presence of NTP and divalent cations, with a preference for ATP and Mn(2+), and required the substrates possessing a 3' un-base-paired region on the RNA template strand. The NS3h helicase activity was proportional to increasing lengths of the 3' un-base-paired regions up to 16 nucleotides of the RNA substrates. We also investigated the modulation of NS3 NTPase/helicase activities by NS3 protease domain and NS5B, an RNA-dependent RNA polymerase (RdRp). Our data showed that the NS3 protease domain enhanced the helicase activity of NS3 but had no effect on its NTPase activity. For the truncated NS3 (helicase domain, NS3h), both NTPase and helicase activities were up-regulated by NS5B. However, for the full-length NS3 (NS3FL), the NTPase activity, but not the helicase activity, was stimulated by NS5B. Maltose-binding protein (MBP) pull-down as well as enzyme-linked immunosorbent assays confirmed the specific interaction between NS3 and NS5B.

Inhibition of G1P3 expression found in the differential display study on respiratory syncytial virus infection.

BACKGROUND: Respiratory syncytial virus (RSV) is the leading viral pathogen associated with bronchiolitis and lower respiratory tract disease in infants and young children worldwide. The respiratory epithelium is the primary initiator of pulmonary inflammation in RSV infections, which cause significant perturbations of global gene expression controlling multiple cellular processes. In this study, differential display reverse transcription polymerase chain reaction amplification was performed to examine mRNA expression in a human alveolar cell line (SPC-A1) infected with RSV. RESULTS: Of the 2,500 interpretable bands on denaturing polyacrylamide gels, 40 (1.6%) cDNA bands were differentially regulated by RSV, in which 28 (70%) appeared to be upregulated and another 12 (30%) appeared to be downregulated. Forty of the expressed sequence tags (EST) were isolated, and 20 matched homologs in GenBank. RSV infection upregulated the mRNA expression of chemokines CC and CXC and interfered with type alpha/beta interferon-inducible gene expression by upregulation of MG11 and downregulation of G1P3. CONCLUSION: RSV replication could induce widespread changes in gene expression including both positive and negative regulation and play a different role in the down-regulation of IFN-alpha and up-regulation of IFN-gamma inducible gene expression, which suggests that RSV interferes with the innate antiviral response of epithelial cells by multiple mechanisms.

12-nt insertion in 3' untranslated region leads to attenuation of classic swine fever virus and protects host against lethal challenge.

We report here the discovery of an attenuation mechanism of classic swine fever virus (CSFV) induced by introduction of a continuous 12-nt (CUUUUUUCUUUU) insertion in viral 3' UTR. The 12-nt insertion sequence was first found in one attenuated vaccine strain HCLV (Hog Cholera Lapinized Virus) which did not exist in other CSFV strains. To address the function of the 12-nt insertion in viral replication and attenuation, we constructed and analyzed two chimeras stemmed from a highly virulent strain Shimen either with introduction of the 12-nt insertion in 3' UTR or the replacement of viral 3' UTR by the 3' UTR of HCLV. We found that the two chimeras' maximum titers declined approximately 100-fold than their parental strain Shimen in PK15 cells. An animal experiment showed that the two chimeras were both dramatically attenuated in pigs. All the chimera-infected pigs survived infection and remained clinically normal with the exception of a transient fever while the 100% mortality was observed for the Shimen-infected pigs. In addition, the two chimeras can induce neutralization antibody to completely protect the pigs against lethal challenge with highly virulent CSFV, which was similar to the vaccine strain HCLV. These data demonstrate that the 12-nt insertion in 3' UTR is sufficient for the attenuation of CSFV. Taken together, a novel attenuation mechanism of CSFV is found and may pave a way to further research for new attenuated vaccine.

The selection pressure analysis of classical swine fever virus envelope protein genes Erns and E2.

Classical swine fever virus, one member of the family Flaviviridae, is the pathogen of CSF, an economically important and highly contagious disease of pigs. Knowledge of virus genes under positive selection pressure can help identify molecular determinants of virulence or pathogenesis without prior knowledge of the mechanisms governing virulence and pathogenesis and clarify the driving force of classical swine fever virus evolution. The positive selection pressure acting on envelope protein genes E(rns), E1 and E2 of classical swine fever virus were assessed and a site-by-site analysis of the d(N)/d(S) ratio was performed, to identify specific codons undergoing diversifying positive selection. Whilst no significant evidence for positive selection was observed in E1, four positively selected sites (208 in E(rns) and 72, 75, and 200 in E2) were identified. The positively selected site (208) of E(rns) corresponds to one of the amino acid substitutions (Ser to Arg) found in an HS-binding CSFV variant. The mutant at the positively selected site (75) is located within an O-glycosylation motif and altered the predicted glycosylation pattern. In addition, Thr at the positively selective site 200 are directly involved with mAb WH308 with which CS vaccine strain does not react, unlike most of the virulent CSFV strains.

A novel role of classical swine fever virus E(rns) glycoprotein in counteracting the newcastle disease virus (NDV)-mediated IFN-beta Induction.

E(rns) is an envelope glycoprotein of classical swine fever virus (CSFV) and has an unusual feature of RNase activity. In the present study, we demonstrate that E(rns) counteracts Newcastle disease virus (NDV)-mediated induction of IFN-beta. For this purpose, E(rns) fused to the enhanced green fluorescent protein (EGFP) was transiently expressed in porcine kidney 15 (PK15) cells. In luciferase activity assay, E(rns)-EGFP was found to prevent IFN-beta promoter-driven luciferase expression and block the induction of IFN-beta promoter mediated by NDV in a dosedependent manner. Through IFN-specific semi-quantitative RT-PCR detection, obvious decrease of IFN-beta mRNA in NDV-infected PK15 cells was observed in the presence of E(rns)-EGFP. In contrast, EGFP alone showed none of this block capacity. In addition, E(rns)-EGFP mutations with RNase inactivation were also found to block NDV-mediated induction of IFN-beta. These evidences establish a novel function for CSFV E(rns) glycoprotein in counteraction of the IFN-beta induction pathway.

Evidence for positive selection on the E2 gene of bovine viral diarrhoea virus type 1.

Despite the growing interest in the molecular epidemiology of pestivirus, there have been few attempts to determine which regions of the pestivirus genome are subject to positive selection, although this may be a key indicator of the nature of the interaction between host and virus. By using likelihood-based methods for phylogenetic inference, the positive selection pressure of BVDV-1 E2 gene were assessed and a site-by-site analysis of the dN/dS ratio was performed, to identify specific codons undergoing diversifying positive selection. The overall omega was 0.20, indicating that most sites were subject to strong purifying selection and five positively selected sites (886, 888, 905, 944, and 946) were identified. It is surprising to find that all the potential positively selected sites fall within the C-terminal of E2, and out of the N-terminal of E2 which is thought to be surface-exposed and therefore prime targets for host antibody response. In conclusion, these results suggest that selection favoring avoidance of antibody recognition has not been a major factor in the history of BVDV-1. Further analysis is necessary to see if amino acid substitutions in the BVDV-1 positively selected sites can lead to change of host tropism or\and escape from epitope-specific CD8 T-cell response.