Structural and Functional Insights into Viral and Fungal Proteins Involved in Chronic Inflammation and Their Biologic Treatments.

Chronic inflammation constitutes a significant characteristic of sustained infections caused by viral and fungal pathogens, with a strong correlation to the development of cancer, autoimmune disorders, and tissue fibrosis. Viral proteins such as HIV-1 Tat, HBV X (HBx), HPV E6/E7, and EBV LMP1 modulate the host's immune signaling pathways, primarily through the activation of the NF-κB signaling cascade and the disruption of cytokine equilibrium. These molecular interactions result in a pro-inflammatory microenvironment that facilitates viral persistence, immune evasion, and the process of oncogenesis. Structural investigations have elucidated the mechanisms by which these viral proteins interact with host signaling complexes, thereby highlighting their potential as viable therapeutic targets. Similarly, fungal proteins, including secreted aspartyl proteases (Saps), ribotoxin Asp f1, and chitin-binding proteins, incite chronic inflammation by activating pattern recognition receptors and triggering inflammasome activation. Despite the limited structural information of these fungal proteins, emerging models and bioinformatic analyses identified conserved motifs that are crucial for host interactions. Biologic therapies, encompassing antiviral and antifungal peptides as well as monoclonal antibodies, are currently under development to disrupt these protein-host interactions and modulate inflammatory responses. This review provides structural and functional insight into viral and fungal inflammatory proteins and evaluates the potential of biologics as targeted therapeutic interventions for chronic inflammation associated with infections. We discuss the ongoing clinical trials involving neutralizing antibodies targeting HIV, peptide vaccines aimed at HPV and other promising molecules. Finally, we discuss the current limitations of biologics and possible solutions to translate these promising therapeutics into clinical practice.