Updated project metadata. The toll-like receptor 4 (TLR4) is a central regulator of innate immune signaling that primarily recognizes bacterial lipopolysaccharide (LPS) cell wall constituents to trigger cytokine secretion. We identify the intramembrane protease RHBDL4 as a negative regulator of TLR4 signaling. We show that RHBDL4-triggers the degradation of TLR4’s trafficking factor TMED7, a member of the p24 family of COPII adaptor proteins, which counteracts the transport of TLR4 to the cell surface. Besides TMED7, RHBDL4 cleaves a subset of related p24 cargo receptors, suggesting that this is a general protein abundance control mechanism to regulate the loading of specific secretory proteins into COPII vesicles. Notably, TLR4 activation by LPS mediates transcriptional upregulation of RHBDL4. Hence, TLR4 activation triggers an RHBDL4-dependent negative feedback loop to reduce the export of newly synthesized TLR4 molecules from the endoplasmic reticulum into COPII-coated vesicles. This secretory cargo tuning mechanism prevents the over-activation of TLR4-dependent signaling and consequently alleviates septic shock in a mouse model.