The ITAM in Nef Influences Acute Pathogenesis of AIDS-Inducing Simian Immunodeficiency Viruses SIVsm and SIVagm without Altering Kinetics or Extent of Viremia

The role of the immunoreceptor tyrosine-based activation motif (ITAM) that is unique to the Nef protein of the acutely pathogenic simian immunodeficiency virus SIVsmPBj was studied in the context of two AIDS-inducing simian immunodeficiency virus molecular clones. NefY(+) variants of SIVagm9063-2 and SIVsmE543-3 replicated in and induced proliferation of unstimulated pig-tailed macaque PBMC. The pathogenesis of the NefY(+) and NefY(−) clones of SIVagm9063-2, SIVsmE543-3, and PBj6.6 were evaluated by intravenous inoculation of pig-tailed macaques (Macaca nemestrina). Introduction of the ITAM did not increase plasma viral RNA levels nor alter the kinetics of viremia compared with the NefY(−) versions of each clone. Clinical symptoms were not observed in animals inoculated with the NefY(−) variants. In contrast, characteristic PBj symptoms were observed in animals inoculated with any of the three NefY(+) clones. Blunting and fusion of intestinal villi and multifocal infiltration of mononuclear cells were observed in the gastrointestinal tracts of macaques inoculated with the NefY(+) versions. Lesions were associated with active viral replication, as demonstrated by simian immunodeficiency virus-specific in situ hybridization. However, only the macaque inoculated with wild-type NefY(+) SIVsmPBj developed fatal disease; lesions were more widespread and severe in this animal. A switch to macrophages as a viral reservoir and the presence of interleukin-6 in plasma was unique to the macaque infected with PBj6.6. Overall, these data suggest that the ITAM in SIV Nef alters the pathogenesis of simian immunodeficiency virus regardless of the viral background. The change in pathogenesis occurs without enhancement of viral replication. However, NefY(+) variants of SIVagm and SIVsm did not fully recapitulate the virulence of SIVsmPBj, implicating additional viral factors in this unique virus pathogenesis

Infectious Molecular Clones from a Simian Immunodeficiency Virus-Infected Rapid-Progressor (RP) Macaque: Evidence of Differential Selection of RP-Specific Envelope Mutations In Vitro and In Vivo

A minor fraction of simian immunodeficiency virus (SIV)-infected macaques progress rapidly to AIDS in the absence of SIV-specific immune responses. Common mutations in conserved residues of env in three SIVsmE543-3-infected rapid-progressor (RP) macaques suggest the evolution of a common viral variant in RP macaques. The goal of the present study was to analyze the biological properties of these variants in vitro and in vivo through the derivation of infectious molecular clones. Virus isolated from a SIVsmE543-3-infected RP macaque, H445 was used to inoculate six naive rhesus macaques. Although RP-specific mutations dominated in H445 tissues, they represented only 10% of the population of the virus stock, suggesting a selective disadvantage in vitro. Only one of these macaques (H635) progressed rapidly to AIDS. Plasma virus during primary infection of H635 was similar to the inoculum. However, RP-specific mutations were apparently rapidly reselected by 4 to 9 weeks postinfection. Terminal plasma from H635 was used as a source of viral RNA to generate seven full-length, infectious molecular clones. With the exception of one clone, which was similar to SIVsmE543-3, clones with RP-specific mutations replicated with delayed kinetics in rhesus peripheral blood mononuclear cells and human T-cell lines. None of the clones replicated in monocyte-derived or alveolar macrophages, and all used CCR5 as their major coreceptor. RP variants appear to be well adapted to replicate in vivo in RP macaques but are at a disadvantage in tissue culture compared to their parent, SIVsmE543-3. Therefore, tissue culture may not provide a good surrogate for replication of RP variants in macaques. These infectious clones will provide a valuable reagent to study the roles of specific viral variants in rapid progression in vivo

Viral contamination in biologic manufacture and implications for emerging therapies

Recombinant protein therapeutics, vaccines, and plasma products have a long record of safety. However, the use of cell culture to produce recombinant proteins is still susceptible to contamination with viruses. These contaminations cost millions of dollars to recover from, can lead to patients not receiving therapies, and are very rare, which makes learning from past events difficult. A consortium of biotech companies, together with the Massachusetts Institute of Technology, has convened to collect data on these events. This industry-wide study provides insights into the most common viral contaminants, the source of those contaminants, the cell lines affected, corrective actions, as well as the impact of such events. These results have implications for the safe and effective production of not just current products, but also emerging cell and gene therapies which have shown much therapeutic promise

Initial Findings From the North American COVID-19 Myocardial Infarction Registry

The coronavirus disease 2019 (COVID-19) pandemic has impacted many aspects of ST-segment elevation myocardial infarction (STEMI) care, including timely access to primary percutaneous coronary intervention (PPCI). The goal of the NACMI (North American COVID-19 and STEMI) registry is to describe demographic characteristics, management strategies, and outcomes of COVID-19 patients with STEMI. A prospective, ongoing observational registry was created under the guidance of 3 cardiology societies. STEMI patients with confirmed COVID+ (group 1) or suspected (person under investigation [PUI]) (group 2) COVID-19 infection were included. A group of age- and sex-matched STEMI patients (matched to COVID+ patients in a 2:1 ratio) treated in the pre-COVID era (2015 to 2019) serves as the control group for comparison of treatment strategies and outcomes (group 3). The primary outcome was a composite of in-hospital death, stroke, recurrent myocardial infarction, or repeat unplanned revascularization. As of December 6, 2020, 1,185 patients were included in the NACMI registry (230 COVID+ patients, 495 PUIs, and 460 control patients). COVID+ patients were more likely to have minority ethnicity (Hispanic 23%, Black 24%) and had a higher prevalence of diabetes mellitus (46%) (all p < 0.001 relative to PUIs). COVID+ patients were more likely to present with cardiogenic shock (18%) but were less likely to receive invasive angiography (78%) (all p < 0.001 relative to control patients). Among COVID+ patients who received angiography, 71% received PPCI and 20% received medical therapy (both p < 0.001 relative to control patients). The primary outcome occurred in 36% of COVID+ patients, 13% of PUIs, and 5% of control patients (p < 0.001 relative to control patients). COVID+ patients with STEMI represent a high-risk group of patients with unique demographic and clinical characteristics. PPCI is feasible and remains the predominant reperfusion strategy, supporting current recommendations. [Display omitted