Role of Exogenous HSPA1A in Cytokine Regulation Through TLR2, TLR4, TLR5, TLR7, and MyD88/MAPK p38/NF-κB Pathways in Differentiated THP-1 Cells

Heat shock proteins (HSPs) are ubiquitous proteins that play an important role in cellular stress responses, contributing to immune activation through interactions with toll-like receptors (TLRs) and other pattern recognition receptors. Despite extensive research, the exact mechanism by which HSPs modulate immune responses is still unclear. This study explores the immune-modulatory role of HSPA1A by examining its effect on cytokine production in PMA-differentiated THP-1 macrophages, preincubated with TLR-specific blocking peptides prior to exposure to recombinant HSPA1A. The results showed that treatment with HSPA1A significantly increased the secretion of both pro-inflammatory cytokines, such as IL-1β and TNF-α, and anti-inflammatory cytokines, such as IL-4 and IL-10, emphasizing its dual role in immune regulation. Blocking peptides targeting TLR2, TLR4, TLR5, and TLR7 were used to study the involvement of these receptors in HSPA1A-induced cytokine production. Further analysis revealed that HSPA1A modulates key signaling pathways, including MyD88, MAPK, and NF-κB. These findings suggest that HSPA1A-TLR interactions and their downstream signaling cascades can be potential therapeutic targets for modulating immune responses in inflammatory and autoimmune diseases.