Comprehensive analysis of immune responses in CLL patients after heterologous COVID-19 vaccination

Patients with chronic lymphocytic leukemia (CLL) treated with B-cell pathway inhibitors and anti-CD20 antibodies exhibit low humoral response rate (RR) following SARS-CoV-2 vaccination. To investigate the relationship between the initial transcriptional response to vaccination with ensuing B and T cell immune responses, we performed a comprehensive immune transcriptome analysis flanked by antibody and T cell assays in peripheral blood prospectively collected from 15 CLL/SLL patients vaccinated with heterologous BNT162b2/ChAdOx1 with follow up at a single institution. The two-dose antibody RR was 40% increasing to 53% after booster. Patients on BTKi, venetoclax {+/-} anti-CD20 antibody within 12 months of vaccination responded less well than those under BTKi alone. The two-dose T cell RR was 80% increasing to 93% after booster. Transcriptome studies revealed that seven patients showed interferon-mediated signaling activation within 2 days and one at 7 days after vaccination. Increasing counts of COVID-19 specific IGHV genes correlated with B-cell reconstitution and improved humoral RR. T cell responses in CLL patients appeared after vaccination regardless of treatment status. A higher humoral RR was associated with BTKi treatment and B-cell reconstitution. Boosting was particularly effective when intrinsic immune status was improved by CLL-treatment.

A novel lenticular arena to quantify locomotor competence in walking fruit flies.

Drosophila melanogaster has become an important invertebrate model organism in biological and medical research, for mutational and genetic analysis, and in toxicological screening. Many screening assays have been developed that assess the flies' mortality, reproduction, development, morphology, or behavioral competence. In this study, we describe a new assay for locomotor competence. It comprises a circular walking arena with a lenticular floor and a flat cover (the slope of the floor increases gradually from the center to the edge of the arena) plus automated fly tracking and statistical analysis. This simple modification of a flat arena presents a graduated physical challenge, with which we can assess fine gradations of motor ability, since a fly's time average radial distance from the arena center is a direct indicator of its climbing ability. The time averaged distribution of flies as a function of slope, activity levels, and walking speed, yields a fine grained picture of locomotory ability and motivation levels. We demonstrate the strengths and weaknesses of this assay (compared with a conventional tap-down test) by observing flies treated with a neurotoxin (BMAA) that acts as a glutamate agonist. The assay proves well suited to detect dose effects and progression effects with higher statistical power than the traditional tap-down, but it has a higher detection limit, making it less sensitive to treatment effects.