Impact of inducible co-stimulatory molecule (ICOS) on T-cell responses and protection against Mycobacterium tuberculosis infection
| Autor: | Tracey A. Day, Mischo Kursar, Geraldine Nouailles, Markus Koch, Pia Gamradt, Robert Hurwitz, Stefan H. E. Kaufmann, Stefanie Kuhlmann, Lydia Pradl, Anca Dorhoi, Sabine Jörg, Delia Loewe, Andreas Hutloff |
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| Rok vydání: | 2010 |
| Předmět: |
Antigens
Differentiation T-Lymphocyte CD4-Positive T-Lymphocytes Tuberculosis T cell Immunology chemical and pharmacologic phenomena Biology CD8-Positive T-Lymphocytes Mycobacterium tuberculosis Inducible T-Cell Co-Stimulator Protein Mice Antigen medicine Immunology and Allergy Animals Mice Knockout Effector CD28 Cell Differentiation biology.organism_classification medicine.disease Mice Inbred C57BL medicine.anatomical_structure Immunologic Memory CD8 Signal Transduction |
| Zdroj: | European journal of immunology. 41(4) |
| ISSN: | 1521-4141 |
| Popis: | Even though Mycobacterium tuberculosis (Mtb) remains one of the top microbial killers, more than 90% of the 2 billion infected individuals never develop active tuberculosis (TB), indicating efficient immune control of infection in these individuals. Immune mechanisms promoting either control or reactivation of TB are incompletely understood. Kinetic analyses of T-cell responses against Mtb in C57BL/6 mice revealed surface expression of inducible co-stimulatory molecule (ICOS) on >30% of all CD4(+) T cells, suggesting a pivotal role of this costimulatory molecule of the CD28 family in TB control. Surprisingly, Mtb-infected ICOS(-/-) mice showed lower bacterial burden during the late chronic stage of infection as compared to WT controls. ICOS deficiency resulted in a reduced Mtb-specific CD8(+) T-cell response during late-stage infection. In contrast, the polyclonal CD4(+) Th1 response against Mtb was increased, most likely caused by diminished numbers and frequencies of Tregs. Thus, by altering effector T-cell populations differentially, ICOS signaling modulates TB control in the late stage of infection. |
| Databáze: | OpenAIRE |
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