Biology subjects

Habrylo, I.

Publications and source records attributed to Habrylo, I..

2 recordsLinked to original sources

bioRxiv2023

Commensal myeloid crosstalk in neonatal skin regulates long-term cutaneous type 17 inflammation

Early life microbe-immune interactions at barrier surfaces have lasting impacts on the trajectory towards health versus disease. Monocytes, macrophages and dendritic cells are primary sentinels in barrier tissues, yet the salient contributions of commensal-myeloid crosstalk during tissue development remain poorly understood. Here, we identify that commensal microbes facilitate accumulation of a population of monocytes in neonatal skin. Transient postnatal depletion of these monocytes resulted in heightened IL-17A production by skin T cells, which was particularly sustained among CD4+ T cells and sufficient to exacerbate inflammatory skin pathologies. Neonatal skin monocytes were enriched in expression of negative regulators of the IL-1 pathway. Functional in vivo experiments confirmed a key role for excessive IL-1R1 signaling in T cells as contributing to the dysregulated type 17 response in neonatal monocyte-depleted mice. Thus, a commensal-driven wave of monocytes into neonatal skin critically facilitates immune homeostasis in this prominent barrier tissue.

immunology↗

bioRxiv2020

FOXO1 promotes HIV Latency by suppressing ER stress in T cells

Quiescence is a hallmark of CD4+ T cells latently infected with HIV-1. While reversing this quiescence is an effective approach to reactivate latent HIV from T cells in culture, it can cause deleterious cytokine dysregulation in patients. Here we report that FOXO1, a key regulator of T-cell quiescence, promotes latency and suppresses productive HIV infection. In resting T cells, FOXO1 inhibition induces ER stress and activates two associated transcription factors: activating transcription factor 4 (ATF4) and nuclear factor of activated T cells (NFAT). Both factors associate with HIV chromatin and are necessary for HIV reactivation. Indeed, inhibition of PKR-like endoplasmic reticulum kinase (PERK), a known link between ER stress and ATF4, and calcineurin, a calcium-dependent regulator of NFAT, synergistically suppress HIV reactivation induced by FOXO1 inhibition. Thus, our studies uncover a novel link between FOXO1, ER stress, and HIV infection that could be therapeutically exploited to selectively reverse T-cell quiescence and reduce the size of the latent viral reservoir.

immunology↗