Cell Specificity of the Transcription-Factor Repertoire Used by a Lentivirus: Motifs Important for Expression of Equine Infectious Anemia Virus in Nonmonocytic Cells

AbstractThe equine infectious anemia virus (EIAV) long-terminal repeat (LTR) has been identified as highly variable, both in infected horses and in cell culture. This nucleotide hypervariation is localized to the LTR enhancer region. The EIAV LTR has been implicated in controlling both the cell tropism and virulence of the virus and it is postulated that the enhancer-region hypervariation may be responsible for the LTR effects. Our previous studies have demonstrated that the presence of DNA motifs bound by the ets transcription-factor family member PU.1 are critically important for EIAV expression in equine macrophages. Here we identify and characterize the EIAV LTR enhancer motifs PEA-2, Lvb, Oct, and CRE, that bind to fibroblast nuclear extracts. Three of these four motifs, PEA-2, Oct, and CRE, were determined to be important for expression of the LTR in a fibroblast cell line that supports productive infection of EIAV. These motifs that are important for expression of the LTR in fibroblasts were found to be interdigitated between the PU.1 sites. We hypothesize that the combination of motif interdigitation and cell-specific usage of these motifs may be responsible for the observed EIAV LTR enhancer-region hypervariation

Characterization of a Cytolytic Strain of Equine Infectious Anemia Virus

A novel strain of equine infectious anemia virus (EIAV) called vMA-1c that rapidly and specifically killed infected equine fibroblasts (ED cells) but not other infectible cell lines was established. This strain was generated from an avirulent, noncytopathic strain of EIAV, MA-1. Studies with this new cytolytic strain of virus have permitted us to define viral parameters associated with EIAV-induced cell killing and begin to explore the mechanism. vMA-1c infection resulted in induction of rapid cell death, enhanced fusogenic activity, and increased rates of spread in equine fibroblasts compared to other strains of EIAV. The highly cytolytic nature of vMA-1c suggested that this strain might be superinfecting equine fibroblasts. Receptor interference studies demonstrated that prior infection of equine fibroblasts with EIAV did not alter the ability of vMA-1c to infect and kill these cells. In similar studies in a canine fibroblast cell line, receptor interference did occur. vMA-1c infection of equine fibroblasts was also associated with large quantities of unintegrated viral DNA, a well-established hallmark of retroviral superinfection. Cloning of the vMA-1c genome identified nucleotide changes that would result in at least one amino acid change in all viral proteins. A chimeric infectious molecular clone containing the vMA-1c tat, S2, and env open reading frames recapitulated most of the characteristics of vMA-1c, including superinfection, fibroblast killing, and fusogenic activity. In summary, in vitro selection for a strain of EIAV that rapidly killed cells resulted in the generation of a virus that was able to superinfect these cells, presumably by the use of a novel mechanism of cell entry. This phenotype mapped to the 3′ half of the genome

An Initiative To Assess and Improve the Resources and Patient Care Processes Used Among Chest Wall Injury Society Collaborative Centers (CWIS-CC2)

Background Over the last two decades, the acute management of rib fractures has changed significantly. In 2021, the Chest Wall injury Society (CWIS) began recognizing centers who epitomize their mission as CWIS Collaborative Centers (CWIS-CC). The primary aim of this study was to determine the resources, surgical expertise, access to care, and institutional support that are present among centers. Methods A survey was performed including all CWIS-CC evaluating the resources available at their hospital for the treatment of patients with chest wall injury. Data about each Chest Wall Injury Center (CWIC) care process, availability of resources, institutional support, research support, and educational offerings were recorded. Results Data was collected from 20 trauma centers resulting in an 80% response rate. These trauma centers were made up of 5 international and 15 US based trauma centers. Eighty percent (16/20) have dedicated care team members for the evaluation and management of rib fractures. Twenty-five percent (5/20) have a dedicated rib fracture service with a separate call schedule. Staffing for chest wall injury clinics consists of a multidisciplinary team: with attending surgeons in all clinics, 80%(8/10) with APPs and 70%(7/10) with care coordinators. Forty percent(8/20) of centers have dedicated rib fracture research support and 35%(7/20) have SSRF-related grants. Forty percent (8/20) of centers have marketing support and 30%(8/20) have a web page support to bring awareness to their center. At these trauma centers, a median of 4(1-9) surgeons perform surgical stabilization of rib fractures (SSRF). In the majority of trauma centers the trauma surgeons perform SSRF. Conclusions Considerable similarities and differences exist within these CWIS collaborative centers. These differences in resources are hypothesis generating in determining the optimal CWIC. These findings may generate several patient care and team process questions to optimize patient care, patient experience, provider satisfaction, research productivity, education, and outreach. Level of Evidence IV Economic & Value-Based Evaluation

An Initiative To Assess and Improve the Resources and Patient Care Processes Used Among Chest Wall Injury Society Collaborative Centers (CWIS-CC2)

Background Over the last two decades, the acute management of rib fractures has changed significantly. In 2021, the Chest Wall injury Society (CWIS) began recognizing centers who epitomize their mission as CWIS Collaborative Centers (CWIS-CC). The primary aim of this study was to determine the resources, surgical expertise, access to care, and institutional support that are present among centers. Methods A survey was performed including all CWIS-CC evaluating the resources available at their hospital for the treatment of patients with chest wall injury. Data about each Chest Wall Injury Center (CWIC) care process, availability of resources, institutional support, research support, and educational offerings were recorded. Results Data was collected from 20 trauma centers resulting in an 80% response rate. These trauma centers were made up of 5 international and 15 US based trauma centers. Eighty percent (16/20) have dedicated care team members for the evaluation and management of rib fractures. Twenty-five percent (5/20) have a dedicated rib fracture service with a separate call schedule. Staffing for chest wall injury clinics consists of a multidisciplinary team: with attending surgeons in all clinics, 80%(8/10) with APPs and 70%(7/10) with care coordinators. Forty percent(8/20) of centers have dedicated rib fracture research support and 35%(7/20) have SSRF-related grants. Forty percent (8/20) of centers have marketing support and 30%(8/20) have a web page support to bring awareness to their center. At these trauma centers, a median of 4(1-9) surgeons perform surgical stabilization of rib fractures (SSRF). In the majority of trauma centers the trauma surgeons perform SSRF. Conclusions Considerable similarities and differences exist within these CWIS collaborative centers. These differences in resources are hypothesis generating in determining the optimal CWIC. These findings may generate several patient care and team process questions to optimize patient care, patient experience, provider satisfaction, research productivity, education, and outreach. Level of Evidence IV Economic & Value-Based Evaluation