Chronic viral infections are widespread among humans, with ∼8-12 chronic viral infections per individual, and there is epidemiological proof that these impair heterologous immunity. We studied the impact of chronic LCMV infection on the phenotype and function of memory bystander CD8 T cells. Active chronic LCMV infection had a profound effect on total numbers, phenotype, and function of memory bystander T cells in mice. The phenotypic changes included up-regulation of markers commonly associated with effector and exhausted cells and were induced by IL-6 in a STAT1-dependent manner in the context of chronic virus infection. Furthermore, bystander CD8 T cell functions were reduced with respect to their ability to produce inflammatory cytokines and to undergo secondary expansion upon cognate antigen challenge with major cell-extrinsic contributions responsible for the diminished memory potential of bystander CD8 T cells. These findings open new perspectives for immunity and vaccination during chronic viral infections.
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http://dx.doi.org/10.1084/jem.20181589 | DOI Listing |
Sci Signal
January 2025
Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA, USA.
Macrophages exposed to immune stimuli reprogram their epigenomes to alter their subsequent functions. Exposure to bacterial lipopolysaccharide (LPS) causes widespread nucleosome remodeling and the formation of thousands of de novo enhancers. We dissected the regulatory logic by which the network of interferon regulatory factors (IRFs) induces the opening of chromatin and the formation of de novo enhancers.
View Article and Find Full Text PDFPLoS One
December 2024
Translational Biology, Medicine and Health Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
Post-traumatic stress disorder (PTSD) is a severe anxiety disorder that affects women more than men. About 30% of patients suffering from PTSD develop the disorder by witnessing a traumatic event happen to someone else. However, as the focus has remained on those directly experiencing the traumatic event, whether indirectly acquired fear memories that underlie PTSD have the same molecular signature as those that are directly acquired remains unknown.
View Article and Find Full Text PDFFront Immunol
December 2024
Immunology Center of Georgia (IMMCG), Medical College of Georgia (MCG), Augusta University, Augusta, GA, United States.
The immune system is endowed with the capacity to distinguish between self and non-self, so-called immune tolerance or "consciousness of the immune system." This type of awareness is designed to achieve host protection by eliminating cells expressing a wide range of non-self antigens including microbial-derived peptides. Such a successful immune response is associated with the secretion of a whole spectrum of soluble mediators, e.
View Article and Find Full Text PDFClin Immunol
December 2024
Department of Immunology, Oslo University Hospital, Oslo, Norway; KG Jebsen Centre for B cell Malignancies, Institute of Clinical Medicine, University of Oslo, Norway; Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway. Electronic address:
Patients with Inflammatory Bowel Disease (IBD) undergoing immunosuppressive therapies face heightened susceptibility to severe COVID-19. An in-depth understanding of systemic inflammation and cellular immune responses after SARS-CoV-2 vaccination and breakthrough infections (BTI) is required for optimizing vaccine strategies in this population. While the prevalence of high serological responders post- third COVID-19 vaccine dose was lower, and the antibody waning was higher in IBD patients than in healthy donors (HD), IBD patients showed an increase in anti-RBD Wild Type IgG levels and cross-reactive Spike -specific memory B cells following BTI.
View Article and Find Full Text PDFBiomed Pharmacother
December 2024
Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea. Electronic address:
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