Allergic inflammation triggers dyslipidemia via IgG signalling.

BACKGROUND: Allergic diseases begin early in life and are often chronic, thus creating an inflammatory environment that may precede or exacerbate other pathologies. In this regard, allergy has been associated to metabolic disorders and with a higher risk of cardiovascular disease, but the underlying mechanisms remain incompletely understood. METHODS: We used a murine model of allergy and atherosclerosis, different diets and sensitization methods, and cell-depleting strategies to ascertain the contribution of acute and late phase inflammation to dyslipidemia. Untargeted lipidomic analyses were applied to define the lipid fingerprint of allergic inflammation at different phases of allergic pathology. Expression of genes related to lipid metabolism was assessed in liver and adipose tissue at different times post-allergen challenge. Also, changes in serum triglycerides (TGs) were evaluated in a group of 59 patients ≥14 days after the onset of an allergic reaction. RESULTS: We found that allergic inflammation induces a unique lipid signature that is characterized by increased serum TGs and changes in the expression of genes related to lipid metabolism in liver and adipose tissue. Alterations in blood TGs following an allergic reaction are independent of T-cell-driven late phase inflammation. On the contrary, the IgG-mediated alternative pathway of anaphylaxis is sufficient to induce a TG increase and a unique lipid profile. Lastly, we demonstrated an increase in serum TGs in 59 patients after undergoing an allergic reaction. CONCLUSION: Overall, this study reveals that IgG-mediated allergic inflammation regulates lipid metabolism.

Dasatinib interferes with HIV-1 proviral integration and the inflammatory potential of monocyte-derived macrophages from people with HIV.

HIV-1 infection is efficiently controlled by the antiretroviral treatment (ART) but viral persistence in long-lived reservoirs formed by CD4 + T cells and macrophages impedes viral eradication and creates a chronic inflammatory environment. Dasatinib is a tyrosine kinase inhibitor clinically used against chronic myeloid leukemia (CML) that has also showed an anti-inflammatory potential. We previously reported that dasatinib is very efficient at interfering with HIV-1 infection of CD4 + T cells by preserving the antiviral activity of SAMHD1, an innate immune factor that blocks T-cell activation and proliferation and that is inactivated by phosphorylation at T592 (pSAMHD1). We observed that short-term treatment in vitro with dasatinib significantly reduced pSAMHD1 in monocyte-derived macrophages (MDMs) isolated from people with HIV (PWH) and healthy donors, interfering with HIV-1 infection. This inhibition was based on low levels of 2-LTR circles and proviral integration, while viral reverse transcription was not affected. MDMs isolated from people with CML on long-term treatment with dasatinib also showed low levels of pSAMHD1 and were resistant to HIV-1 infection. In addition, dasatinib decreased the inflammatory potential of MDMs by reducing the release of M1-related cytokines like TNFα, IL-1ß, IL-6, CXCL8, and CXCL9, but preserving the antiviral activity through normal levels of IL-12 and IFNγ. Due to the production of M2-related anti-inflammatory cytokines like IL-1RA and IL-10 was also impaired, dasatinib appeared to interfere with MDMs differentiation. The use of dasatinib along with ART could be used against HIV-1 reservoir in CD4 and macrophages and to alleviate the chronic inflammation characteristic of PWH.