Sublytic

Sublytic is an adjective used in biology to describe concentrations or doses of a lytic agent that are below the threshold needed to cause cell lysis. It is commonly applied in immunology and toxinology, where such sublytic levels can affect cells without causing immediate rupture. Sublytic effects may include changes in membrane permeability, ion flux, receptor shedding, or the activation of intracellular signaling, all occurring without overt cell death.

In the context of the complement system, the membrane attack complex (MAC) can insert into cellular membranes. Sublytic MAC deposition refers to amounts that do not lyse the cell but can alter membrane properties and trigger cellular responses. These responses may involve activation of inflammatory pathways, changes in gene expression, or other signaling events that influence cell behavior and survival, depending on the cell type and conditions.

In toxinology and related fields, sublytic doses of pore-forming toxins or other lytic agents can induce functional changes such as calcium influx, cytoskeletal remodeling, and mediator release, rather than immediate necrosis or apoptosis. The boundary between sublytic and lytic effects varies with organism, cell type, and environmental factors.

The concept of sublytic effects is used to study dose-dependent cellular outcomes, the mechanisms of membrane damage, and their relevance to disease processes, vascular injury, and toxin safety assessments. Etymologically, it combines sub- (under) with lysis (dissolution) to denote effects that are not fully lytic.