Biology subjects

Goplen, N.

Publications and source records attributed to Goplen, N..

2 recordsLinked to original sources

bioRxiv2020

Tissue-resident CD8+ T cells drive age-associated chronic lung sequelae following viral pneumonia

Lower respiratory viral infections, such as influenza virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infections, often cause severe viral pneumonia in aged individuals. Here, we report that influenza viral pneumonia leads to chronic non-resolving lung pathology and exaggerated accumulation of CD8+ tissue-resident memory T cells (TRM) in the respiratory tract of aged hosts. TRM accumulation relies on elevated TGF-{beta} present in aged tissues. Further, we show that TRM isolated from aged lungs lack a subpopulation characterized by expression of molecules involved in TCR signaling and effector function. Consequently, TRM cells from aged lungs were insufficient to provide heterologous protective immunity. Strikingly, the depletion of CD8+ TRM cells dampens persistent chronic lung inflammation and ameliorates tissue fibrosis in aged, but not young, animals. Collectively, our data demonstrate that age-associated TRM cell malfunction supports chronic lung inflammatory and fibrotic sequelae following viral pneumonia in aged hosts.

immunology↗

bioRxiv2019

Inhibition of Stearoyl-CoA desaturase suppresses follicular help T and germinal center B cell responses

Stearoyl-CoA desaturases (SCD) are endoplasmic reticulum (ER) associated enzymes that catalyze the synthesis of the monounsaturated fatty acids (MUFAs). As such, SCD play important roles in maintaining the intracellular balance between saturated fatty acid (SFAs) and MUFAs. The roles of SCD in CD4+ T helper cell responses are currently unexplored. Here, we have found that murine and human follicular helper T (TFH) cells express higher levels of SCD1 compared to non-TFH cells. Further, the expression of SCD1 in TFH cells is dependent on the TFH lineage-specification transcription factor BCL6. We found that the inhibition of SCD1 impaired TFH cell maintenance and shifted the balance between TFH and follicular regulatory T (TFR) cells in the spleen. Consequently, SCD1 inhibition dampened germinal center B cell responses following influenza immunization. Mechanistically, we found that SCD inhibition led to increased ER stress and enhanced TFH cell apoptosis in vitro and in vivo. These results reveal a possible link between fatty acid metabolism and cellular and humoral responses induced by immunization or potentially, autoimmunity.

immunology↗