Immunological Insights Into the Therapeutic Roles of CD24Fc Against Severe COVID-19

BACKGROUNDSARS-CoV-2 causes COVID-19 through direct lysis of infected lung epithelial cells, which releases damage-associated molecular patterns (DAMPs) and induces a pro-inflammatory cytokine milieu causing systemic inflammation. Anti-viral and anti-inflammatory agents have shown limited therapeutic efficacy. Soluble CD24 (CD24Fc) is able to blunt the broad inflammatory response induced by DAMPs in multiple models. A recent randomized phase III trial evaluating the impact of CD24Fc in patients with severe COVID-19 demonstrated encouraging clinical efficacy. METHODSWe studied peripheral blood samples obtained from patients enrolled at a single institution in the SAC-COVID trial (NCT04317040) collected before and after treatment with CD24Fc or placebo. We performed high dimensional spectral flow cytometry analysis of peripheral blood mononuclear cells and measured the levels of a broad array of cytokines and chemokines. A systems analytical approach was used to discern the impact of CD24Fc treatment on immune homeostasis in patients with COVID-19. FINDINGSTwenty-two patients were enrolled, and the clinical characteristics from the CD24Fc vs. placebo groups were matched. Using high-content spectral flow cytometry and network-level analysis, we found systemic hyper-activation of multiple cellular compartments in the placebo group, including CD8+ T cells, CD4+ T cells, and CD56+ NK cells. By contrast, CD24Fc-treated patients demonstrated blunted systemic inflammation, with a return to homeostasis in both NK and T cells within days without compromising the ability of patients to mount an effective anti-Spike protein antibody response. A single dose of CD24Fc significantly attenuated induction of the systemic cytokine response, including expression of IL-10 and IL-15, and diminished the coexpression and network connectivity among extensive circulating inflammatory cytokines, the parameters associated with COVID-19 disease severity. INTERPRETATIONOur data demonstrates that CD24Fc treatment rapidly down-modulates systemic inflammation and restores immune homeostasis in SARS-CoV-2-infected individuals, supporting further development of CD24Fc as a novel therapeutic against severe COVID-19. FUNDINGNIH

Motivational interviewing techniques and the harm-reduction model in a short-term substance-abuse group for adolescents with psychiatric problems.

The authors describe techniques and practical examples for working with substance-abusing teens within a short-term psychiatric setting that derive from the Harm-Reduction model and the Motivational Interviewing approach.

Bovine cells expressing bovine herpesvirus 1 (BHV-1) glycoprotein IV resist infection by BHV-1, herpes simplex virus, and pseudorabies virus.

We expressed the bovine herpesvirus 1 (BHV-1) glycoprotein IV (gIV) in bovine cells. The protein expressed was identical in molecular mass and antigenic reactivity to the native gIV protein but was localized in the cytoplasm. Expressing cells were partially resistant to BHV-1, herpes simplex virus, and pseudorabies virus, as shown by a 10- to 1,000-fold-lower number of plaques forming on these cells than on control cells. The level of resistance depended on the level of gIV expression and the type and amount of challenge virus. These data are consistent with previous reports by others that cellular expression of the BHV-1 gIV homologs, herpes simplex virus glycoprotein D, and pseudorabies virus glycoprotein gp50 provide partial resistance against infection with these viruses. We have extended these findings by showing that once BHV-1 enters gIV-expressing cells, it replicates and spreads normally, as shown by the normal size of BHV-1 plaques and the delayed but vigorous synthesis of viral proteins. Our data are consistent with the binding of BHV-1 gIV to a cellular receptor required for initial penetration by all three herpesviruses and interference with the function of that receptor molecule.

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We expressed the bovine herpesvirus type 1 (BHV-1) glycoproteins, gI and gIII, in bovine cells using a bovine papillomavirus vector. The proteins expressed by these cells had the same Mr as the native BHV-1 proteins and monoclonal antibodies detected no differences in their antigenic structure. Cells expressing gI were infected with either BHV-1 or herpes simplex virus type 1 (HSV-1). The number of plaques in gI-expressing cells was similar to that seen with normal fibroblasts infected with BHV-1 or HSV-1. However, BHV-1 or HSV-1 plaques produced in gI-expressing cells were smaller and darker than those seen in normal fibroblasts indicating an interference with cell-to-cell transmission or cellular lysis. Virus growth curves and [35S]methionine labelling of BHV-1-infected gI-expressing cells showed no difference in virus production, virus protein synthesis or cellular protein shutdown when compared to BHV-1-infected normal cells. This led us to conclude that the gI protein may interfere with a cellular protein(s) responsible for the cytopathic effects of BHV-1 infection. Cells expressing gIII were fully susceptible to BHV-1 infection.