Heat Shock 70kDa Protein 14 (HSPA14)

HSP70L1 expression was upregulated by heat stress, TNF-alpha, and phorbol esters. HSP70L1 interacted with human dendritic cells (DCs), resulting in DC maturation and activation. Although HSP70L1 shared common cell surface receptors with HSP70 (HSPA1A), including TLR2 and TLR4, there were functional differences between the 2 proteins. HSP70L1 and HSP70 stimulated DC secretion of the proinflammatory cytokines IL1B and TNF-alpha at comparable levels, but HSP70L1 was a more potent stimulator of IL12p70. HSP70L1 induced secretion of the chemokines MIP1A (CCL3), MIP1B (CCL4), and RANTES (CCL5) and expression of the chemokine receptors CCR7 and CXCR4 more potently than HSP70. In addition, HSP70L1, but not HSP70, could induce IP10 (CXCL10) secretion.