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bioRxiv · 10.1101/680157

Criticality of plasma membrane lipids reflects activation state of macrophage cells

Cammarota, E.·Soriani, C.·Taub, R.·Morgan, F.·Sakai, J.·Veatch, S.·Bryant, C. E.·Cicuta, P.
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Abstract

Signalling is of particular importance in immune cells, and upstream in the signalling pathway many membrane receptors are functional only as complexes, co-locating with particular lipid species. Work over the last 15 years has shown that plasma membrane lipid composition is close to a critical point of phase separation, with evidence that cells adapt their composition in ways that alter the proximity to this thermodynamical point. Macrophage cells are a key component of the innate immune system, responsive to infections, regulating the local state of inflammation. We investigate changes in the plasma membranes proximity to the critical point, as a response to stimulation by various pro- and anti-inflammatory agents. Pro-inflammatory (IFN-{gamma}, Kdo-LipidA, LPS) perturbations induce an increase in the transition temperature of the GMPVs; anti-inflammatory IL4 has the opposite effect. These changes recapitulate complex plasma membrane composition changes, and are consistent with lipid criticality playing a master regulatory role: being closer to critical conditions increases membrane protein activity.

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Cammarota, E., Soriani, C., Taub, R., Morgan, F., Sakai, J., Veatch, S., Bryant, C. E., Cicuta, P.. 2019-06-23. Criticality of plasma membrane lipids reflects activation state of macrophage cells. https://doi.org/10.1101/680157

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