IL-22: An Underestimated Player in Natural Resistance to Tuberculosis?
Approximately 10% of individuals latently infected with Mycobacterium tuberculosis (Mtb) develop active tuberculosis (TB) during their lifetime. Although it is well recognized that T-helper 1 immune responses are crucial for containing latent TB infection, the full array of host factors conferring p...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-09-01
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| Series: | Frontiers in Immunology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fimmu.2018.02209/full |
| _version_ | 1818478674852184064 |
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| author | Katharina Ronacher Katharina Ronacher Roma Sinha Michelle Cestari |
| author_facet | Katharina Ronacher Katharina Ronacher Roma Sinha Michelle Cestari |
| author_sort | Katharina Ronacher |
| collection | DOAJ |
| description | Approximately 10% of individuals latently infected with Mycobacterium tuberculosis (Mtb) develop active tuberculosis (TB) during their lifetime. Although it is well recognized that T-helper 1 immune responses are crucial for containing latent TB infection, the full array of host factors conferring protective immunity from TB progression are not completely understood. IL-22 is produced by cells of the innate and adaptive immune system including innate lymphoid cells, and natural killer cells as well as T lymphocytes (Th1, Th17, and Th22) and binds to its cognate receptor, the IL-22R1, which is expressed on non-hematopoietic cells such as lung epithelial cells. However, recent studies suggest that Mtb induces expression of the IL-22R1 on infected macrophages and multiple studies have indicated a protective role of IL-22 in respiratory tract infections. Reduced concentrations of circulating IL-22 in active TB compared to latent TB and decreased percentages of Mtb-specific IL-22 producing T cells in TB patients compared to controls designate this cytokine as a key player in TB immunology. More recently, it has been shown that in type 2 diabetes (T2D) and TB co-morbidity serum IL-22 concentrations are further reduced compared to TB patients without co-morbidities. However, whether a causative link between low IL-22 and increased susceptibility to TB and disease severity of TB exists remains to be established. This review summarizes the contribution of IL-22, a potentially under-appreciated key player in natural resistance to TB, at the interface between the immune response to Mtb and the lung epithelium. |
| first_indexed | 2024-12-10T09:50:41Z |
| format | Article |
| id | doaj.art-a5d456c615a84f50941ba31247716ee5 |
| institution | Directory Open Access Journal |
| issn | 1664-3224 |
| language | English |
| last_indexed | 2024-12-10T09:50:41Z |
| publishDate | 2018-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Immunology |
| spelling | doaj.art-a5d456c615a84f50941ba31247716ee52022-12-22T01:53:41ZengFrontiers Media S.A.Frontiers in Immunology1664-32242018-09-01910.3389/fimmu.2018.02209386027IL-22: An Underestimated Player in Natural Resistance to Tuberculosis?Katharina Ronacher0Katharina Ronacher1Roma Sinha2Michelle Cestari3Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, SAMRC Centre for Tuberculosis Research, DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, Stellenbosch University, Cape Town, South AfricaInfection, Immunity and Metabolism Group, Translational Research Institute, Mater Research Institute and The University of Queensland, Brisbane, QLD, AustraliaInfection, Immunity and Metabolism Group, Translational Research Institute, Mater Research Institute and The University of Queensland, Brisbane, QLD, AustraliaInfection, Immunity and Metabolism Group, Translational Research Institute, Mater Research Institute and The University of Queensland, Brisbane, QLD, AustraliaApproximately 10% of individuals latently infected with Mycobacterium tuberculosis (Mtb) develop active tuberculosis (TB) during their lifetime. Although it is well recognized that T-helper 1 immune responses are crucial for containing latent TB infection, the full array of host factors conferring protective immunity from TB progression are not completely understood. IL-22 is produced by cells of the innate and adaptive immune system including innate lymphoid cells, and natural killer cells as well as T lymphocytes (Th1, Th17, and Th22) and binds to its cognate receptor, the IL-22R1, which is expressed on non-hematopoietic cells such as lung epithelial cells. However, recent studies suggest that Mtb induces expression of the IL-22R1 on infected macrophages and multiple studies have indicated a protective role of IL-22 in respiratory tract infections. Reduced concentrations of circulating IL-22 in active TB compared to latent TB and decreased percentages of Mtb-specific IL-22 producing T cells in TB patients compared to controls designate this cytokine as a key player in TB immunology. More recently, it has been shown that in type 2 diabetes (T2D) and TB co-morbidity serum IL-22 concentrations are further reduced compared to TB patients without co-morbidities. However, whether a causative link between low IL-22 and increased susceptibility to TB and disease severity of TB exists remains to be established. This review summarizes the contribution of IL-22, a potentially under-appreciated key player in natural resistance to TB, at the interface between the immune response to Mtb and the lung epithelium.https://www.frontiersin.org/article/10.3389/fimmu.2018.02209/fulltuberculosisMycobacterium tuberculosisinterleukin-22IL-22R1T lymphocytesrespiratory infections |
| spellingShingle | Katharina Ronacher Katharina Ronacher Roma Sinha Michelle Cestari IL-22: An Underestimated Player in Natural Resistance to Tuberculosis? Frontiers in Immunology tuberculosis Mycobacterium tuberculosis interleukin-22 IL-22R1 T lymphocytes respiratory infections |
| title | IL-22: An Underestimated Player in Natural Resistance to Tuberculosis? |
| title_full | IL-22: An Underestimated Player in Natural Resistance to Tuberculosis? |
| title_fullStr | IL-22: An Underestimated Player in Natural Resistance to Tuberculosis? |
| title_full_unstemmed | IL-22: An Underestimated Player in Natural Resistance to Tuberculosis? |
| title_short | IL-22: An Underestimated Player in Natural Resistance to Tuberculosis? |
| title_sort | il 22 an underestimated player in natural resistance to tuberculosis |
| topic | tuberculosis Mycobacterium tuberculosis interleukin-22 IL-22R1 T lymphocytes respiratory infections |
| url | https://www.frontiersin.org/article/10.3389/fimmu.2018.02209/full |
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