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Di Castro MA, Garofalo S, Mormino A, Carbonari L, Di Pietro E, De Felice E, Catalano M, Maggi L, Limatola C. Interleukin-15 alters hippocampal synaptic transmission and impairs episodic memory formation in mice. Brain Behav Immun 2024; 115:652-666. [PMID: 37992787 DOI: 10.1016/j.bbi.2023.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 11/09/2023] [Accepted: 11/12/2023] [Indexed: 11/24/2023] Open
Abstract
Cytokines are potent immunomodulators exerting pleiotropic effects in the central nervous system (CNS). They influence neuronal functions and circuit activities with effects on memory processes and behaviors. Here, we unravel a neuromodulatory activity of interleukin-15 (IL-15) in mouse brain. Acute exposure of hippocampal slices to IL-15 enhances gamma-aminobutyricacid (GABA) release and reduces glutamatergic currents, while chronic treatment with IL-15 increases the frequency of hippocampal miniature inhibitory synaptic transmission and impairs memory formation in the novel object recognition (NOR) test. Moreover, we describe that serotonin is involved in mediating the hippocampal effects of IL-15, because a selective 5-HT3A receptor antagonist prevents the effects on inhibitory neurotransmission and ameliorates mice performance in the NOR test. These findings provide new insights into the modulatory activities of cytokines in the CNS, with implications on behavior.
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Affiliation(s)
- Maria Amalia Di Castro
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Stefano Garofalo
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Alessandro Mormino
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Laura Carbonari
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Erika Di Pietro
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Eleonora De Felice
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Myriam Catalano
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Laura Maggi
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome, Italy
| | - Cristina Limatola
- IRCCS Neuromed Via Atinese 18, 86077 Pozzilli, Italy; Department of Physiology and Pharmacology, Sapienza University, Laboratory affiliated to Istituto Pasteur, Italy.
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Golzari-Sorkheh M, Zúñiga-Pflücker JC. Development and function of FOXP3+ regulators of immune responses. Clin Exp Immunol 2023; 213:13-22. [PMID: 37085947 PMCID: PMC10324550 DOI: 10.1093/cei/uxad048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/08/2023] [Accepted: 04/21/2023] [Indexed: 04/23/2023] Open
Abstract
The Forkhead Box P3 (FOXP3) protein is an essential transcription factor for the development and function of regulatory T cells (Tregs), involved in the maintenance of immunological tolerance. Although extensive research over the last decade has investigated the critical role of FOXP3+ cells in preserving immune homeostasis, our understanding of their specific functions remains limited. Therefore, unveiling the molecular mechanisms underpinning the up- and downstream transcriptional regulation of and by FOXP3 is crucial for developing Treg-targeted therapeutics. Dysfunctions in FOXP3+ Tregs have also been found to be inherent drivers of autoimmune disorders and have been shown to exhibit multifaceted functions in the context of cancer. Recent research suggests that these cells may also be involved in tissue-specific repair and regeneration. Herein, we summarize current understanding of the thymic-transcriptional regulatory landscape of FOXP3+ Tregs, their epigenetic modulators, and associated signaling pathways. Finally, we highlight the contributions of FOXP3 on the functional development of Tregs and reflect on the clinical implications in the context of pathological and physiological immune responses.
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Affiliation(s)
| | - Juan Carlos Zúñiga-Pflücker
- Department of Immunology, University of Toronto, Toronto, ON, Canada
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada
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Chandiran K, Cauley LS. The diverse effects of transforming growth factor-β and SMAD signaling pathways during the CTL response. Front Immunol 2023; 14:1199671. [PMID: 37426662 PMCID: PMC10327426 DOI: 10.3389/fimmu.2023.1199671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/12/2023] [Indexed: 07/11/2023] Open
Abstract
Cytotoxic T lymphocytes (CTLs) play an important role in defense against infections with intracellular pathogens and anti-tumor immunity. Efficient migration is required to locate and destroy infected cells in different regions of the body. CTLs accomplish this task by differentiating into specialized subsets of effector and memory CD8 T cells that traffic to different tissues. Transforming growth factor-beta (TGFβ) belongs to a large family of growth factors that elicit diverse cellular responses via canonical and non-canonical signaling pathways. Canonical SMAD-dependent signaling pathways are required to coordinate changes in homing receptor expression as CTLs traffic between different tissues. In this review, we discuss the various ways that TGFβ and SMAD-dependent signaling pathways shape the cellular immune response and transcriptional programming of newly activated CTLs. As protective immunity requires access to the circulation, emphasis is placed on cellular processes that are required for cell-migration through the vasculature.
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Affiliation(s)
- Karthik Chandiran
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Linda S. Cauley
- Department of Immunology, UCONN Health, Farmington, CT, United States
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Geginat J, Granucci F. Regulatory T-cell-derived interleukin-15 shapes cytotoxic T cell memory. Eur J Immunol 2023; 53:e2250238. [PMID: 36398486 DOI: 10.1002/eji.202250238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022]
Abstract
It is well known that regulatory T-cells (Tregs) are required to prevent autoimmunity, but they may also have some less-well understood immune-stimulatory effects. In particular, in CD8+ T-cell responses Tregs select high-affinity clones upon priming and promote memory by inhibiting inflammation-dependent generation of short-lived effector cells. In the current issue of the European Journal of Immunology [Eur. J. Immunol. 2023. 53: 2149400], Madi et al. report the surprising finding that human and murine FOXP3+ Tregs are a physiologically relevant source of IL-15, a homeostatic cytokine that promotes antigen-independent maintenance of CD8+ memory T-cells. In mice that lack IL-15 selectively in FOXP3+ Tregs the authors show that the composition of the CD8+ T-cell memory pool is altered in the absence of Treg-derived IL-15, since a subset of terminally effector memory cells is drastically reduced. Otherwise Treg-derived IL-15 is dispensable for antiviral immune responses and the generation of anti-viral CD8+ memory T-cells. These findings add to our understanding of the multifaceted role of Tregs in immune responses, and how IL-15 derived from different cellular sources maintains anti-viral T-cell memory.
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Affiliation(s)
- Jens Geginat
- University of Milan, Department of Clinical Sciences and Community Health, Milan, Italy.,Fondazione Istituto Nazionale di Genetica Molecolare "Romeo ed Enrica Invernizzi", Milan, Italy
| | - Francesca Granucci
- University of Milano-Bicocca, Department of Biotechnology and Biosciences, Milan, Italy
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