Host Cellular and Immune Systems

Host Cellular and Immune Systems refers to the integrated network of biological structures and processes that protect an organism against disease by identifying and killing pathogens and tumor cells (StatPearls, 2023). This is not a single molecular target but a broad physiological system comprising the innate and adaptive immune branches, as well as the cellular machinery required for viral replication or bacterial survival (NIH, 2024). In modern pharmacology, the concept of host-directed therapy (HDT) involves modulating these systems to improve treatment outcomes, particularly in cases of antimicrobial resistance or hyper-inflammation (Nature Reviews Drug Discovery, 2020). For example, drugs may target host cytokines, signaling kinases, or checkpoint proteins to enhance the host's natural defenses or prevent tissue damage. Because this term encompasses thousands of distinct proteins and cell types, it is considered too broad for specific target validation in drug discovery. Consequently, while it is the focus of therapeutic intervention, it does not meet the criteria for a discrete, canonical molecular target.

Other names

Host immune systemHost factorsHost-directed therapy targets

Varies widely depending on the specific component targeted; includes the modulation of host signaling pathways, activation or suppression of immune cell subsets, and regulation of inflammatory cascades to treat disease.