Host cell-surface receptors and attachment factors

Host cell-surface receptors and attachment factors are a heterogeneous class of molecules—including glycoproteins, glycolipids, and glycosaminoglycans—that serve as the primary interface for pathogen docking and internalization. Attachment factors, such as heparan sulfate proteoglycans (HSPGs), facilitate the initial, often non-specific, recruitment of pathogens to the cell surface, increasing the local concentration of infectious agents (Maginnis, 2018). In contrast, entry receptors are highly specific molecules, such as Angiotensin-converting enzyme 2 (ACE2) for SARS-CoV-2 or CD4 for HIV-1, that undergo or induce conformational changes necessary for membrane fusion or endocytosis (Marsh & Helenius, 2006). These molecules are essential for the initiation of the infectious cycle, making them significant targets for antiviral and antibacterial therapies. Targeting these host factors is a key strategy in developing host-directed therapies, which may offer a higher barrier to resistance compared to drugs targeting rapidly mutating viral proteins (Shehu et al., 2022). However, because these molecules typically perform vital physiological roles, such as blood pressure regulation or immune signaling, pharmacological modulation carries risks of systemic toxicity and functional impairment (Baranowski et al., 2001). Current therapeutic examples include CCR5 antagonists like Maraviroc, which prevent HIV entry by blocking the coreceptor required for viral fusion.

Other names

Host cell receptorsViral attachment factorsCell surface entry receptorsPathogen receptorsHost entry factors

Competitive inhibition of pathogen binding sites, allosteric modulation of host receptor conformation to prevent membrane fusion, or enzymatic modification of attachment factors to reduce pathogen affinity.