Back

Haptoglobin buffers lipopolysaccharides to safeguard against aberrant NFκB activation

Zein, L.; Grossmann, J.; Swoboda, H.; Borgel, C.; Wilke, B.; Awe, S.; Nist, A.; Stiewe, T.; Stehling, O.; Freibert, S.-A.; Adhikary, T.; Chung, H.-R.

2022-11-22 immunology
10.1101/2022.11.22.516855 bioRxiv
Show abstract

It has remained yet unclear which soluble factors regulate the anti-inflammatory macrophage phenotype observed in both homeostasis and tumourigenesis. We show here that haptoglobin, a major serum pro-tein with elusive immunoregulatory properties, binds and buffers serum-borne bacterial lipopolysaccharides to attenuate activation of NF{kappa}B in macrophages. Haptoglobin binds different lipopolysaccharides with low micromolar affinities. Given its abundance, haptoglobin constitutes a buffer for lipopolysaccharides, shielding them to safeguard against aberrant inflammatory reactions caused by small fluctuations. Concordantly, NF{kappa}B activation by haptoglobin-associated lipopolysaccharides was delayed relative to stimulation with pure lipopolysaccharide. Our findings warrant evaluation of therapeutic benefits of haptoglobin for inflammatory conditions and re-evaluation of purification strategies. Finally, they allow to elucidate mechanisms of enhanced immunosuppression by oncofetal haptoglobin.

Matching journals

The top 11 journals account for 50% of the predicted probability mass.

50% of probability mass above

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.