The Altered Neonatal CD8 T Cell Immunodominance Hierarchy during Influenza Virus Infection Impacts Peptide Vaccination.

Neonates are more susceptible to influenza virus infection than adults, resulting in increased morbidity and mortality and delayed clearance of the virus. Generating effective CD8 T cell responses may be important for improving vaccination outcomes in vulnerable populations, but neonatal T cells frequently respond differently than adult cells. We sought to understand CD8 T cell specificity and immunodominance during neonatal influenza infection and how any differences from the adult hierarchy might impact peptide vaccine effectiveness.

Unfolded Von Willebrand Factor Binds Protein S and Reduces Anticoagulant Activity.

Protein S (PS), the critical plasma cofactor for the anticoagulants tissue factor (TF) pathway inhibitor (TFPI) and activated protein C (APC), circulates in two functionally distinct pools: free (anticoagulant) or bound to complement component 4b-binding protein (C4BP) (anti-inflammatory). Acquired free PS deficiency is detected in several viral infections, but its cause is unclear. Here, we identified a shear-dependent interaction between PS and von Willebrand Factor (VWF) by mass spectrometry.

Deep learning, 3D ultrastructural analysis reveals quantitative differences in platelet and organelle packing in COVID-19/SARSCoV2 patient-derived platelets.

Platelets contribute to COVID-19 clinical manifestations, of which microclotting in the pulmonary vasculature has been a prominent symptom. To investigate the potential diagnostic contributions of overall platelet morphology and their α-granules and mitochondria to the understanding of platelet hyperactivation and micro-clotting, we undertook a 3D ultrastructural approach. Because differences might be small, we used the high-contrast, high-resolution technique of focused ion beam scanning EM (FIB-SEM) and employed deep learning computational methods to evaluate nearly 600 individual platelets and 30 000 included organelles within three healthy controls and three severely ill COVID-19 patients.

Long-term high-dose immunoglobulin successfully treats Long COVID patients with pulmonary, neurologic, and cardiologic symptoms.

Introduction: Long COVID is the overarching name for a wide variety of disorders that may follow the diagnosis of acute SARS-COVID-19 infection and persist for weeks to many months. Nearly every organ system may be affected.

Methods: We report nine patients suffering with Long COVID for 101 to 547 days.

Total Plasma Protein S Is a Prothrombotic Marker in People Living With HIV.

Background: HIV-1 infection is associated with multiple procoagulant changes and increased thrombotic risk. Possible mechanisms for this risk include heigthened expression of procoagulant tissue factor (TF) on circulating monocytes, extracellular vesicles, and viral particles and/or acquired deficiency of protein S (PS), a critical cofactor for the anticoagulant protein C (PC). PS deficiency occurs in up to 76% of people living with HIV-1 (PLWH).