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Biology subjects

Lycke, N.

Publications and source records attributed to Lycke, N..

3 recordsLinked to original sources

Nasal tissue-resident memory CD4+ T cells persist after influenza A virus infection and provide heterosubtypic protection

CD4 tissue-resident memory T cells (TRM) are crucial adaptive immune components involved in preventing influenza A virus (IAV) infection. Despite their importance, their physiological role in the upper respiratory tract, the first site of contact with IAV, remains unclear. Here, we find that, after IAV infection, antigen-specific CD4 TRM persist in the nasal tissue (NT) compartment after infection and provide protection upon heterosubtypic challenge. Single cell RNA sequencing analysis reveals that NT CD4 TRM are heterogeneous and transcriptionally distinct as compared to their lung counterparts. Mechanistically, we demonstrate that the CXCR6-CXCL16 axis promotes CD4 TRM residency in the NT. Furthermore, we show that the NT of mice and humans contains a high frequency of Th17 CD4 TRM that aid in local viral clearance and in reducing tissue damage. Collectively, our results support a robust physiological role for nasal tissue CD4 TRM in local protection during heterosubtypic IAV infection.

immunology↗

Tr1 cell-mediated protection against autoimmune disease by intranasal administration of a fusion protein targeting cDC1 cells

Curative therapies against autoimmune diseases are lacking. Indeed, most of currently available treatments are only targeting symptoms. We have developed a novel strategy for a therapeutic vaccine against autoimmune diseases based on intranasal administration of a fusion protein tolerogen, which consists of a mutant, enzymatically inactive, cholera toxin A1-subunit genetically fused to disease relevant high affinity peptides and a dimer of D-fragments from protein A. The CTA1R7K-MOG/PLP-DD fusion proteins effectively reduced clinical symptoms in the experimental autoimmune encephalitis (EAE)-model of multiple sclerosis (MS). The treatment induced Tr1 cells, in the draining lymph node, which produced IL-10 and suppressed effector CD4+ T cell responses. This effect was dependent on IL-27 signalling, since treatment was ineffective in bone marrow chimeras lacking IL-27R within their hematopoietic compartment. scRNA-seq of dendritic cells (DC) in draining lymph nodes demonstrated distinct gene transcriptional changes of cDC1, including enhanced lipid metabolic pathways, induced by the tolerogenic fusion protein. Thus, our results with the tolerogenic fusion protein demonstrates the possibility to vaccinate and protect against disease progression by reinstating tolerance in MS and other autoimmune diseases.

immunology↗

Single cell BCR and transcriptome analysis after respiratory virus infection reveals spatiotemporal dynamics of antigen-specific B cell responses.

B cell responses are a critical component of anti-viral immunity. However, a comprehensive picture of antigen-specific B cell responses, differentiation, clonal proliferation and dynamics in different organs after infection is lacking. Here, we combined single-cell RNA sequencing with single-cell B cell receptor (BCR) characterization of antigen-specific cells in the draining lymph nodes, spleen and lungs after influenza infection. We identify several novel B cell subpopulations forming after infection and find organ-specific differences that persist over the course of the response. We discover important transcriptional differences between memory cells in lungs and lymphoid organs and describe organ-restricted clonal expansion. Strikingly, by combining BCR mutational analysis, monoclonal antibody expression and affinity measurements we find no differences between germinal center (GC)-derived memory and plasmacells, at odds with an affinity-based selection model. By linking antigen-recognition with transcriptional programming, clonal-proliferation and differentiation, these finding provide important advances in our understanding of antiviral B cell immunity.

immunology↗