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Choi J, Augenlicht LH. Intestinal stem cells: guardians of homeostasis in health and aging amid environmental challenges. Exp Mol Med 2024; 56:495-500. [PMID: 38424189 PMCID: PMC10985084 DOI: 10.1038/s12276-024-01179-1] [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: 11/14/2023] [Accepted: 12/11/2023] [Indexed: 03/02/2024] Open
Abstract
The intestinal epithelium is the first line of defense and acts as an interface between the vast microbial world within the gastrointestinal tract and the body's internal milieu. The intestinal epithelium not only facilitates nutrient absorption but also plays a key role in defending against pathogens and regulating the immune system. Central to maintaining a healthy epithelium are intestinal stem cells (ISCs), which are essential for replenishing the intestinal epithelium throughout an individual's lifespan. Recent research has unveiled the intricate interplay between ISCs and their niche, which includes various cell types, extracellular components, and signaling molecules. In this review, we delve into the most recent advances in ISC research, with a focus on the roles of ISCs in maintaining mucosal homeostasis and how ISC functionality is influenced by the niche environment. In this review, we explored the regulatory mechanisms that govern ISC behavior, emphasizing the dynamic adaptability of the intestinal epithelium in the face of various challenges. Understanding the intricate regulation of ISCs and the impact of aging and environmental factors is crucial for advancing our knowledge and developing translational approaches. Future studies should investigate the interactive effects of different risk factors on intestinal function and develop strategies for improving the regenerative capacity of the gut.
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Affiliation(s)
- Jiahn Choi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Leonard H Augenlicht
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
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2
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Longet S, Paul S. Pivotal role of tissue-resident memory lymphocytes in the control of mucosal infections: can mucosal vaccination induce protective tissue-resident memory T and B cells? Front Immunol 2023; 14:1216402. [PMID: 37753095 PMCID: PMC10518612 DOI: 10.3389/fimmu.2023.1216402] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 08/28/2023] [Indexed: 09/28/2023] Open
Affiliation(s)
- Stephanie Longet
- Centre International de Recherche en Infectiologie, Team Groupe sur l'immunité des muqueuses et agents pathogènes (GIMAP), Université Jean Monnet, Université Claude Bernard Lyon, Inserm, Saint-Etienne, France
| | - Stephane Paul
- Centre International de Recherche en Infectiologie, Team Groupe sur l'immunité des muqueuses et agents pathogènes (GIMAP), Université Jean Monnet, Université Claude Bernard Lyon, Inserm, Saint-Etienne, France
- Centre d'investigation clinique (CIC) 1408 Inserm Vaccinology, University Hospital of Saint-Etienne, Saint-Etienne, France
- Immunology Department, iBiothera Reference Center, University Hospital of Saint-Etienne, Saint-Etienne, France
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Zhang L, Yan J, Zhang C, Feng S, Zhan Z, Bao Y, Zhang S, Chao G. Improving intestinal inflammaging to delay aging? A new perspective. Mech Ageing Dev 2023; 214:111841. [PMID: 37393959 DOI: 10.1016/j.mad.2023.111841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/14/2023] [Accepted: 06/29/2023] [Indexed: 07/04/2023]
Abstract
Greying population is becoming an increasingly critical issue for social development. In advanced aging context, organismal multiple tissues and organs experience a progressive deterioration, initially presenting with functional decline, followed by structural disruption and eventually organ failure. The aging of the gut is one of the key links. Decreased gut function leads to reduced nutrient absorption and can perturb systemic metabolic rates. The degeneration of the intestinal structure causes the migration of harmful components such as pathogens and toxins, inducing pathophysiological changes in other organs through the "brain-gut axis" and "liver-gut axis". There is no accepted singular underlying mechanism of aged gut. While the inflamm-aging theory was first proposed in 2000, the mutual promotion of chronic inflammation and aging has attracted much attention. Numerous studies have established that gut microbiome composition, gut immune function, and gut barrier integrity are involved in the formation of inflammaging in the aging gut. Remarkably, inflammaging additionally drives the development of aging-like phenotypes, such as microbiota dysbiosis and impaired intestinal barrier, via a broad array of inflammatory mediators. Here we demonstrate the mechanisms of inflammaging in the gut and explore whether aging-like phenotypes in the gut can be negated by improving gut inflammaging.
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Affiliation(s)
- Lan Zhang
- Department of General Practice, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310000, China
| | - Junbin Yan
- The Second Affiliated Hospital of Zhejiang Chinese Medical University, The Xin Hua Hospital of Zhejiang Province, Hangzhou 310000, China
| | - Chi Zhang
- Endoscopic Center, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310000, China
| | - Shuyan Feng
- Zhejiang Chinese Medical University, Hangzhou 310000, China
| | - Zheli Zhan
- Department of General Practice, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310000, China
| | - Yang Bao
- Department of General Practice, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310000, China
| | - Shuo Zhang
- The Second Affiliated Hospital of Zhejiang Chinese Medical University, The Xin Hua Hospital of Zhejiang Province, Hangzhou 310000, China.
| | - Guanqun Chao
- Department of General Practice, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310000, China.
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Das S, Howlader DR, Lu T, Whittier SK, Hu G, Sharma S, Dietz ZK, Ratnakaram SSK, Varisco DJ, Ernst RK, Picking WD, Picking WL. Immunogenicity and protective efficacy of nanoparticle formulations of L-SseB against Salmonella infection. Front Immunol 2023; 14:1208848. [PMID: 37457702 PMCID: PMC10347375 DOI: 10.3389/fimmu.2023.1208848] [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: 04/19/2023] [Accepted: 06/13/2023] [Indexed: 07/18/2023] Open
Abstract
Salmonella enterica, a Gram-negative pathogen, has over 2500 serovars that infect a wide range of hosts. In humans, S. enterica causes typhoid or gastroenteritis and is a major public health concern. In this study, SseB (the tip protein of the Salmonella pathogenicity island 2 type III secretion system) was fused with the LTA1 subunit of labile-toxin from enterotoxigenic E. coli to make the self-adjuvanting antigen L-SseB. Two unique nanoparticle formulations were developed to allow multimeric presentation of L-SseB. Mice were vaccinated with these formulations and protective efficacy determined via challenging the mice with S. enterica serovars. The polysaccharide (chitosan) formulation was found to elicit better protection when compared to the squalene nanoemulsion. When the polysaccharide formulation was used to vaccinate rabbits, protection from S. enterica challenge was elicited. In summary, L-SseB in a particulate polysaccharide formulation appears to be an attractive candidate vaccine capable of broad protection against S. enterica.
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Affiliation(s)
- Sayan Das
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
| | - Debaki R. Howlader
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
| | - Ti Lu
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
| | - Sean K. Whittier
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
| | - Gang Hu
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
| | - Simran Sharma
- Department of Veterinary Pathobiology and Bond Life Science Center, University of Missouri, Columbia, MO, United States
| | - Zackary K. Dietz
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
| | - Siva S. K. Ratnakaram
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
| | - David J. Varisco
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, United States
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, United States
| | - William D. Picking
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
| | - Wendy L. Picking
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, United States
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Allen JC, Toapanta FR, Baliban SM, Sztein MB, Tennant SM. Reduced immunogenicity of a live Salmonella enterica serovar Typhimurium vaccine in aged mice. Front Immunol 2023; 14:1190339. [PMID: 37207226 PMCID: PMC10188964 DOI: 10.3389/fimmu.2023.1190339] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 04/13/2023] [Indexed: 05/21/2023] Open
Abstract
Introduction Non-typhoidal Salmonella (NTS) is responsible for a high burden of foodborne infections and deaths worldwide. In the United States, NTS infections are the leading cause of hospitalizations and deaths due to foodborne illnesses, and older adults (≥65 years) are disproportionately affected by Salmonella infections. Due to this public health concern, we have developed a live attenuated vaccine, CVD 1926 (I77 ΔguaBA ΔclpP ΔpipA ΔhtrA), against Salmonella enterica serovar Typhimurium, a common serovar of NTS. Little is known about the effect of age on oral vaccine responses, and due to the decline in immune function with age, it is critical to evaluate vaccine candidates in older age groups during early product development. Methods In this study, adult (six-to-eight-week-old) and aged (18-month-old) C57BL/6 mice received two doses of CVD 1926 (109 CFU/dose) or PBS perorally, and animals were evaluated for antibody and cell-mediated immune responses. A separate set of mice were immunized and then pre-treated with streptomycin and challenged orally with 108 CFU of wild-type S. Typhimurium SL1344 at 4 weeks postimmunization. Results Compared to PBS-immunized mice, adult mice immunized with CVD 1926 had significantly lower S. Typhimurium counts in the spleen, liver, and small intestine upon challenge. In contrast, there were no differences in bacterial loads in the tissues of vaccinated versus PBS aged mice. Aged mice exhibited reduced Salmonella-specific antibody titers in the serum and feces following immunization with CVD 1926 compared to adult mice. In terms of T cell responses (T-CMI), immunized adult mice showed an increase in the frequency of IFN-γ- and IL-2-producing splenic CD4 T cells, IFN-γ- and TNF-α-producing Peyer's Patch (PP)-derived CD4 T cells, and IFN-γ- and TNF-α-producing splenic CD8 T cells compared to adult mice administered PBS. In contrast, in aged mice, T-CMI responses were similar in vaccinated versus PBS mice. CVD 1926 elicited significantly more PP-derived multifunctional T cells in adult compared to aged mice. Conclusion These data suggest that our candidate live attenuated S. Typhimurium vaccine, CVD 1926, may not be sufficiently protective or immunogenic in older humans and that mucosal responses to live-attenuated vaccines decrease with increasing age.
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Affiliation(s)
- Jessica C. Allen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Franklin R. Toapanta
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Scott M. Baliban
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Marcelo B. Sztein
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Sharon M. Tennant
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
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Differential Homing Receptor Profiles of Lymphocytes Induced by Attenuated versus Live Plasmodium falciparum Sporozoites. Vaccines (Basel) 2022; 10:vaccines10101768. [PMID: 36298634 PMCID: PMC9611729 DOI: 10.3390/vaccines10101768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 10/02/2022] [Accepted: 10/11/2022] [Indexed: 11/17/2022] Open
Abstract
The onset of an adaptive immune response provides the signals required for differentiation of antigen-specific lymphocytes into effector cells and imprinting of these cells for re-circulation to the most appropriate anatomical site (i.e., homing). Lymphocyte homing is governed by the expression of tissue-specific lymphocyte homing receptors that bind to unique tissue-specific ligands on endothelial cells. In this study, a whole-parasite malaria vaccine (radiation-attenuated sporozoites (RAS)) was used as a model system to establish homing receptor signatures induced by the parasite delivered through mosquito bite to provide a benchmark of desirable homing receptors for malaria vaccine developers. This immunization regimen resulted in the priming of antigen-specific B cells and CD8+ T cells for homing primarily to the skin and T/B cell compartments of secondary lymphoid organs. Infection with live sporozoites, however, triggers the upregulation of homing receptor for the liver and the skin, demonstrating that there is a difference in the signal provided by attenuated vs. live sporozoites. This is the first report on imprinting of homing routes by Plasmodium sporozoites and, surprisingly, it also points to additional, yet to be identified, signals provided by live parasites that prime lymphocytes for homing to the liver. The data also demonstrate the utility of this method for assessing the potential of vaccine formulations to direct antigen-specific lymphocytes to the most relevant anatomical site, thus potentially impacting vaccine efficacy.
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The Intestinal Barrier Dysfunction as Driving Factor of Inflammaging. Nutrients 2022; 14:nu14050949. [PMID: 35267924 PMCID: PMC8912763 DOI: 10.3390/nu14050949] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/17/2022] [Accepted: 02/21/2022] [Indexed: 12/13/2022] Open
Abstract
The intestinal barrier, composed of the luminal microbiota, the mucus layer, and the physical barrier consisting of epithelial cells and immune cells, the latter residing underneath and within the epithelial cells, plays a special role in health and disease. While there is growing knowledge on the changes to the different layers associated with disease development, the barrier function also plays an important role during aging. Besides changes in the composition and function of cellular junctions, the entire gastrointestinal physiology contributes to essential age-related changes. This is also reflected by substantial differences in the microbial composition throughout the life span. Even though it remains difficult to define physiological age-related changes and to distinguish them from early signs of pathologies, studies in centenarians provide insights into the intestinal barrier features associated with longevity. The knowledge reviewed in this narrative review article might contribute to the definition of strategies to prevent the development of diseases in the elderly. Thus, targeted interventions to improve overall barrier function will be important disease prevention strategies for healthy aging in the future.
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