T cell–derived soluble glycoprotein GPIbα mediates PGE ₂ production in human monocytes activated with the vaccine adjuvant MDP

Abstract

Vaccine adjuvants containing analogs of microbial products activate pattern recognition receptors (PRRs) on antigen-presenting cells, including monocytes and macrophages, which can cause prostaglandin E2 (PGE2) release and consequently undesired inflammatory responses and fever in vaccine recipients. Here, we studied the mechanism of PGE2 production by human monocytes activated with muramyl dipeptide (MDP) adjuvant, which activates cytosolic nucleotide-binding oligomerization domain 2 (NOD2). In rabbits, administration of MDP elicited an early increase in PGE2 followed by fever. In human monocytes, MDP alone did not induce PGE2 production. However, high amounts of PGE2 and the proinflammatory cytokines IL-1β and IL-6 were secreted by monocytes activated with MDP in the presence of conditioned medium obtained from CD3 bead–isolated T cells (Tc CM) but not from those isolated without CD3 beads. Mass spectrometry and immunoblotting revealed that the costimulatory factor in Tc CM was glycoprotein Ib α (GPIbα). Antibody-mediated blockade of GPIbα or of its receptor, Mac-1 integrin, inhibited the secretion of PGE2, IL-1β, and IL-6 in MDP + Tc CM–activated monocytes, whereas recombinant GPIbα protein increased PGE2 production by MDP-treated monocytes. In vivo, COX2 mRNA abundance was reduced in the liver and spleen of Mac-1 KO mice after administration of MDP compared with that of treated wild-type mice. Our findings suggest that the production of PGE2 and proinflammatory cytokines by MDP-activated monocytes is mediated by cooperation between two signaling pathways: one delivered by MDP through NOD2 and a second through activation of Mac-1 by T cell–derived GPIbα.

D-dimer and CoV-2 spike-immune complexes contribute to the production of PGE2 and proinflammatory cytokines in monocytes

“…Experiments using multiple inhibitors showed that DD and IC utilize common as well unique signaling pathways: ERK1/2 MAP kinase was responsible for upregulation of PGE2, IL-6, and IL-8 suggesting that ERK1/2 plays indispensable role in activation of pyrogenic and pro-inflammatory mediators in monocytes activated with DD and IC. Cytosolic [Ca2+] was required for production of PGE2, IL-6, and IL-8 in monocytes activated with DD alone in agreement with our earlier observations that signaling from αMβ2 integrin increases cytosolic [Ca2+] in monocytes [ 46 ]. Interestingly, in monocytes activated with DD in the presence of IC, the contribution of calcium signaling varied as inhibitor of IP 3 R completely blocked PGE2 but not IL-6 or IL-8 production suggesting that production of pro-inflammatory cytokines was partially [Ca2+] independent.…”

Mice Dually Disrupted for Nod2 and Mincle Manifest Early Bacteriological Control but Late Susceptibility During Mycobacterium tuberculosis Infection

“…When infected with Mtb , human PBMCs with functional NOD2 produced more IL-1 than human PBMCs containing the NOD2 3020insC mutation ( 32 ). MDP also promoted PGE2 production by monocytes and macrophages ( 33 , 34 ). The balance of immune mediators like type I IFN, IL-1 and PGE2 may play a key role in pulmonary cell death during Mtb infection.…”

Characterization of protein unable to bind von Willebrand factor in recombinant factor VIII products

“…The resulting peptides were resolved and analyzed by nanoflow liquid chromatography coupled to tandem mass spectrometry using a Thermo Fisher Ultimate LC and Fusion Orbitrap MS by following typical settings at Food and Drug Administration’s (FDA's) Facility for Biotechnology Resources 28 . For identification, Proteome Discoverer 2.1 (Thermo Fisher Scientific) was used to match tandem mass spectometry spectra to peptides using Swiss‐Prot human database with typical setting as previously reported 29 . For quantification using a label‐free approach, the peptides were quantified by integrating (at 20 ppm tolerance) the signal intensities obtained from extracted ion chromatogram of respective peptides (Table S3).…”

“…28 For identification, Proteome Discoverer 2.1 (Thermo Fisher Scientific) was used to match tandem mass spectometry spectra to peptides using Swiss-Prot human database with typical setting as previously reported. 29 For quantification using a label-free approach, the peptides were quantified by integrating (at 20 ppm tolerance) the signal intensities obtained from extracted ion chromatogram of respective peptides (Table S3).…”