Latreille, E. | Search bioRxiv

bioRxiv2025

Cigarette smoke exposure sets up a pro-inflammatory circuit in the lung that induces the hyper-activation of myelin-specific T helper cells

Cigarette smoke (CS) exposure increases the risk of multiple sclerosis; however, the mechanisms are unclear. To investigate this, we exposed C57BL6/J mice to CS or ambient air (AA) for 8 weeks using a protocol modelling human chronic CS exposure and studied the impact of these exposures on the development of experimental autoimmune encephalomyelitis (EAE). We found that CS increased the incidence of neurological signs in 2D2 myelin oligodendrocyte glycoprotein (MOG) T cell receptor transgenic mice, whereas in active EAE induced by MOG peptide and Complete Freunds adjuvant, CS delayed the onset of disease. In both cases, the effects of CS tended to be greater in the males who also developed greater leukocyte infiltration and expression of IL-12p40 and other cytokines. To gain insights into the paradoxical effects of CS in these EAE models, we transferred congenically-marked pMOG-reactive T helper cells into AA- or CS-exposed mice and examined the phenotype of these cells in the lungs, spleen, and spinal cord. We found that CS-exposed lungs acted as a sink for the pMOG-reactive T cells, in that more of these T cells homed to the lungs instead of the spinal cord. However, these CS-educated pMOG Th cells exhibited a hyperactivated Th phenotype with greater expression of activation markers, IL-17, and GM-CSF, a cytokine that is essential for EAE development. Intranasal treatment with anti-IL-12p40 negated these effects of CS on the expression of pro-inflammatory cytokines by pMOG Th cells. These studies suggest that CS sets up a pro-inflammatory circuit in the lung that amplifies the encephalitogenic properties of myelin-specific T effector cells. HighlightsO_LICS exposure enhances the development of spontaneous neuroimmunity. C_LIO_LIMyelin-reactive T helper 1 responses are enhanced by CS exposure. C_LIO_LICS-exposed lung attracts myelin-specific T helper cells to this site. C_LIO_LICS enhances myelin-specific Th1/Th17 cytokine production and GM-CSF through lung IL-12p40 C_LI

immunology↗

bioRxiv2020

Fatty Acid Synthase inhibition prevents palmitoylation of SARS-CoV2 SpikeProtein and improves survival of mice infected with murine hepatitis virus.

The Spike protein of SARS-CoV2 and other coronaviruses mediate host cell entry and are S-acylated on multiple phylogenetically conserved cysteine residues. Multiple protein acyltransferase enzymes of the ZDHHC family have been reported to modify Spike proteins post-translationally. Using resin-assisted capture mass spectrometry, we demonstrate that the Spike protein is S-acylated in SARS-CoV2 infected human and monkey cells. We further show that increased abundance of the human acyltransferase ZDHHC5 results in increased S-acylation of the SARS-CoV2 Spike protein, whereas ZDHHC5 knockout cells had a 40% reduction in the incorporation of an alkynyl-palmitate using click chemistry detection. We also find that the S-acylation of the Spike protein is not limited to palmitate, as clickable versions of myristate and stearate were also found on the immunocaptured protein. Yet, ZDHHC5 was highly selective for palmitate, suggesting that other ZDHHC enzymes mediated the incorporation of other fatty acyl chains. Thus, since multiple ZDHHC isoforms may modify the Spike protein, we examined the ability of the fatty acid synthase inhibitor TVB-3166 to prevent the S-acylation of the Spike proteins of SARS-CoV-2 and human CoV-229E. Treating cells with TVB-3166 inhibited S-acylation of ectopically expressed SARS-CoV2 Spike and attenuated the ability of SARS-CoV2 and human CoV-229E to spread in vitro. Additionally, treatment of mice with a comparatively low dose of TVB-3166 promoted survival from an otherwise fatal murine coronavirus infection. Our findings further substantiate the necessity of CoV Spike protein S-acylation and the potential use of fatty acid synthase inhibitors.

cell biology↗