Intercellular viral spread and intracellular transposition of Drosophila gypsy.

It has become increasingly clear that retrotransposons (RTEs) are more widely expressed in somatic tissues than previously appreciated. RTE expression has been implicated in a myriad of biological processes ranging from normal development and aging, to age related diseases such as cancer and neurodegeneration. Long Terminal Repeat (LTR)-RTEs are evolutionary ancestors to, and share many features with, exogenous retroviruses. In fact, many organisms contain endogenous retroviruses (ERVs) derived from exogenous retroviruses that integrated into the germ line. These ERVs are inherited in Mendelian fashion like RTEs, and some retain the ability to transmit between cells like viruses, while others develop the ability to act as RTEs. The process of evolutionary transition between LTR-RTE and retroviruses is thought to involve multiple steps by which the element loses or gains the ability to transmit copies between cells versus the ability to replicate intracellularly. But, typically, these two modes of transmission are incompatible because they require assembly in different sub-cellular compartments. Like murine IAP/IAP-E elements, the gypsy family of retroelements in arthropods appear to sit along this evolutionary transition. Indeed, there is some evidence that gypsy may exhibit retroviral properties. Given that gypsy elements have been found to actively mobilize in neurons and glial cells during normal aging and in models of neurodegeneration, this raises the question of whether gypsy replication in somatic cells occurs via intracellular retrotransposition, intercellular viral spread, or some combination of the two. These modes of replication in somatic tissues would have quite different biological implications. Here, we demonstrate that Drosophila gypsy is capable of both cell-associated and cell-free viral transmission between cultured S2 cells of somatic origin. Further, we demonstrate that the ability of gypsy to move between cells is dependent upon a functional copy of its viral envelope protein. This argues that the gypsy element has transitioned from an RTE into a functional endogenous retrovirus with the acquisition of its envelope gene. On the other hand, we also find that intracellular retrotransposition of the same genomic copy of gypsy can occur in the absence of the Env protein. Thus, gypsy exhibits both intracellular retrotransposition and intercellular viral transmission as modes of replicating its genome.

Severe Acute Respiratory Syndrome Coronavirus 2 Convalescent Plasma Versus Standard Plasma in Coronavirus Disease 2019 Infected Hospitalized Patients in New York: A Double-Blind Randomized Trial.

OBJECTIVES: Four peer-reviewed publications have reported results from randomized controlled trials of convalescent plasma for coronavirus disease 2019 infection; none were conducted in the United States nor used standard plasma as a comparator. To determine if administration of convalescent plasma to patients with coronavirus disease 2019 increases antibodies to severe acute respiratory syndrome coronavirus 2 and improves outcome. DESIGN: Double-blind randomized controlled trial. SETTING: Hospital in New York. PATIENTS: Patients with polymerase chain reaction documented coronavirus disease 2019 infection. INTERVENTIONS: Patients were randomized (4:1) to receive 2 U of convalescent plasma versus standard plasma. Antibodies to severe acute respiratory syndrome coronavirus 2 were measured in plasma units and in trial recipients. MEASUREMENTS AND MAIN RESULTS: Enrollment was terminated after emergency use authorization was granted for convalescent plasma. Seventy-four patients were randomized. At baseline, mean (sd) Acute Physiology and Chronic Health Evaluation II score (23.4 [5.6] and 22.5 [6.6]), percent of patients intubated (19% and 20%), and median (interquartile range) days from symptom onset to randomization of 9 (6-18) and 9 (6-15), were similar in the convalescent plasma versus standard plasma arms, respectively. Convalescent plasma had high neutralizing activity (median [interquartile range] titer 1:526 [1:359-1:786]) and its administration increased antibodies to severe acute respiratory syndrome coronavirus 2 by 14.4%, whereas standard plasma administration led to an 8.6% decrease (p = 0.005). No difference was observed for ventilator-free days through 28 days (primary study endpoint): median (interquartile range) of 28 (2-28) versus 28 (0-28; p = 0.86) for the convalescent plasma and standard plasma groups, respectively. A greater than or equal to 2 point improvement in the World Health Organization scale was achieved by 20% of subjects in both arms (p = 0.99). All-cause mortality through 90 days was numerically lower in the convalescent plasma versus standard plasma groups (27% vs 33%; p = 0.63) but did not achieve statistical significance. A key prespecified subgroup analysis of time to death in patients who were intubated at baseline was statistically significant; however, sample size numbers were small. CONCLUSIONS: Administration of convalescent plasma to hospitalized patients with coronavirus disease 2019 infection increased antibodies to severe acute respiratory syndrome coronavirus disease 2 but was not associated with improved outcome.

Prevalence of IgM and IgG antibodies to SARS-CoV-2 in health care workers at a tertiary care New York hospital during the Spring COVID-19 surge.

BACKGROUND: Health care workers (HCW) such as anesthesiologists, surgeons, and intensivists face high rates of exposure to SARS-CoV-2 through direct contact with COVID-19 patients. While there are initial reports of the prevalence of COVID-19 antibodies among the general population, there are few reports comparing the seroprevalence of IgM/IgG COVID-19 antibodies in HCW of different exposure levels as well as different HCW professions. METHODS: A convenience sample of health care workers provided blood for COVID-19 antibody testing and a review of medical history and work exposure for correlative analyses. RESULTS: Overall, 474 HCW were enrolled in April 2020 including 102 front-line physicians (e.g., anesthesiologists, surgeons, intensivists, emergency medicine), 91 other physicians, 135 nurses, 134 other clinical staff, and 12 non-clinical HCW. The prevalence of IgM or IgG antibodies to SARS-CoV-2 was 16.9% (95% CI 13.6-20.6) (80/474). The proportion of positive antibodies in the PCR + group was significantly higher than health care workers without symptoms (84.6% [95% CI 54.6-98.1] vs. 12.3% [95% CI 8.5-17.2], p < 0.001). No significant differences in proportions of COVID-19 antibodies were observed among the different exposure groups (e.g., high vs minimal/no exposure) and among the different HCW professionals. CONCLUSIONS: Despite exposure to COVID-19 patients, the prevalence of antibodies in our HCW was similar to what has been reported for the general population of New York State (14%) and for another New York HCW cohort (13.7%). Health care workers with higher exposure rates were not more likely to have been infected with COVID-19. Therefore, these data suggest that infection of HCW may result from exposure in the community rather than at work. TRIAL REGISTRATION: This investigator-initiated study was observational; therefore, no registration was required. Not applicable.

Impact of serological and PCR testing requirements on the selection of COVID-19 convalescent plasma donors.

BACKGROUND: Convalescent plasma is undergoing randomized trials as a potential therapeutic option for COVID-19 infection. Little empirical evidence exists regarding the determination of donor eligibility and experiences with donor selection. STUDY DESIGN AND METHODS: This prospective study was conducted at a tertiary care hospital in New York to select plasma donors for a randomized, double-blind, controlled convalescent plasma trial. Clearance for donation required successful completion of an online questionnaire and an in-person screening visit, which included (a) completion of a Donor Health Questionnaire (DHQ), (b) Immunoglobulin G (IgG) antibody testing using an immunochromatographic anti- severe acute respiratory coronavirus 2 (SARS-CoV-2) test, (c) Polymerase chain reaction (PCR) testing if <28 days from symptom resolution, and (d) routine blood bank testing. RESULTS: After receiving 3093 online questionnaires, 521 individuals presented for in-person screening visits, with 40.1% (n = 209) fully qualifying. Subjects (n = 312) failed to progress due to the following reasons: disqualifying answer from DHQ (n = 30, 9.6%), insufficient antibodies (n = 198, 63.5%), persistent positive PCR tests (n = 14, 4.5%), and blood donation testing labs (n = 70, 22.4%). Importantly, 24.6% and 11.1% of potential donors who reported having PCR-diagnosed infection had low or undetectable SARS-CoV-2 antibody levels, respectively. Surprisingly, 62.9% (56/89) of subjects had positive PCR tests 14-27 days after symptom resolution, with 13 individuals continuing to be PCR positive after 27 days. CONCLUSION: It is feasible for a single site to fully qualify a large number of convalescent plasma donors in a short period of time. Among otherwise qualified convalescent plasma donors, we found high rates of low or undetectable antibody levels and many individuals with persistently positive PCR tests.

Human Dendritic Cells Mitigate NK-Cell Dysfunction Mediated by Nonselective JAK1/2 Blockade.

Janus kinase (JAK) inhibitors have achieved positive responses in myeloproliferative neoplasms, but at the expense of decreased natural killer (NK) cell numbers and compromised function. Selective JAK2 inhibition may also have a role in preventing and treating graft-versus-host disease after allogeneic hematopoietic stem cell transplantation. Although JAK inhibitors can impair monocyte-derived dendritic cell (moDC) activation and function and suppress effector T-cell responses, the effects on NK cells and the relevant mechanisms remain undefined. Using common γc cytokines and distinct human dendritic cell (DC) subtypes, we compared the effects of a JAK2-specific (TG101348) with a less selective JAK1/2 (ruxolitinib) inhibitor on NK-cell activation and function. Ruxolitinib treatment completely blocked IL2, IL15, and DC-mediated STAT5 phosphorylation, along with the capacity of NK cells to secrete IFNγ or lyse NK cell-sensitive targets. Only NK-cell proliferation stimulated by moDCs resisted ruxolitinib treatment. In contrast, TG101348 treatment of stimulated NK cells resulted in far less functional compromise. TG101348 completely inhibited only soluble IL15-mediated STAT5 phosphorylation, which Langerhans-type DCs (LCs), presenting membrane-bound IL15 in trans, could salvage. These results demonstrate that ruxolitinib's nonselective inhibition of JAK1/2 results in profound NK-cell dysfunction by blocking downstream pSTAT5, hence providing a persuasive rationale for the development of selective JAK2 inhibitors for immunotherapeutic applications. Cancer Immunol Res; 5(1); 52-60. ©2016 AACR.

Repeated mild traumatic brain injury causes focal response in lateral septum and hippocampus.

AIM: To advance our understanding of regional and temporal cellular responses to repeated mild traumatic brain injury (rmTBI), we used a mouse model of rmTBI that incorporated acceleration, deceleration and rotational forces. MATERIALS & METHODS: A modified weight-drop method was used to compare two inter-injury intervals, rmTBI-short (five hits delivered over 3 days) and rmTBI-long (five hits delivered over 15 days). Regional investigations of forebrain and midbrain histological alterations were performed at three post-injury time points (immediate, 2 weeks and 6 weeks). RESULTS: The rmTBI-short protocol generated an immediate, localized microglial and astroglial response in the dorsolateral septum and hippocampus, with the astroglial response persisting in the dorsolateral septum. The rmTBI-long protocol showed only a transitory astroglial response in the dorsolateral septum. CONCLUSION: Our results indicate that the lateral septum and hippocampus are particularly vulnerable regions in rmTBI, possibly contributing to memory and emotional impairments associated with repeated concussions.