Nature uses multivalency to govern many biological processes. The development of macromolecular and cellular therapies has largely been dependent on engineering similar polyvalent interactions to enable effective targeting. Such therapeutics typically utilize high-affinity binding domains that have the propensity to recognize both antigen-overexpressing tumors and normal-expressing tissues, leading to “on-target, off-tumor” toxicities. One strategy to improve these agents’ selectivity is to reduce the binding affinity, such that biologically relevant interactions between the therapeutic and target cell will only exist under conditions of high avidity. Pre-clinical studies have validated this principle of avidity optimization in the context of chimeric antigen receptor (CAR) T cells; however, a rigorous analysis of this approach in the context of soluble multivalent targeting scaffolds has yet to be undertaken. Using a modular protein nanoring capable of displaying ≤8 fibronectin domains with engineered specificity for a model antigen, epithelial cell adhesion molecule (EpCAM), this study demonstrates that binding affinity and ligand valency can be optimized to afford discrimination between EpCAMHigh (2.8 – 3.8 ×106 antigens/cell) and EpCAMLow (5.2×104 – 2.2×105 antigens/cell) tissues both in vitro and in vivo.

Polygraph recordings were conducted with normal subjects who were not sleep‐deprived lo examine the association between EFG alpha dynamics and a passive behavioral index of sleep/ wake status, and to assess the usefulness of that index in subjects who do not produce abundant wakeful alpha activity. I In‐ behavioral indicator of sleep unset comprised the depression of a telegraph key initialed by loss of extensor tension in the finger. Alpha abundant (high‐alpha) subjects showed a strong association of alpha level (as sleep Stage Wake (w) vs. Stage I sleep) with behavioral level, and a strong association of alpha loss events with key closure events. Mean latencies between alpha loss and key closure varied from ‐ 1.8 to 18.4 s with a median of 1.0 s. As expected, high‐alpha subjects also showed significant correlations between alpha level and changes in peripheral physiological variables in the vicinity of sustained alpha losses. Compared with Stage W. Stage 1 was associated with a greater incidence of slow eye movements, lower abdominal breathing amplitude, and a higher thoracic:abdominal breathing ratio. Similar correlations were observed in both high‐alpha and low‐alpha subjects between these variables and the key index, supporting its potential generality as an indicator of sleep onset.

No abstract

No abstract

No abstract