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Stepkowski S, Bekbolsynov D, Oenick J, Brar S, Mierzejewska B, Rees MA, Ekwenna O. The Major Role of T Regulatory Cells in the Efficiency of Vaccination in General and Immunocompromised Populations: A Review. Vaccines (Basel) 2024; 12:992. [PMID: 39340024 PMCID: PMC11436018 DOI: 10.3390/vaccines12090992] [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: 07/17/2024] [Revised: 08/27/2024] [Accepted: 08/28/2024] [Indexed: 09/30/2024] Open
Abstract
Since their conception with the smallpox vaccine, vaccines used worldwide have mitigated multiple pandemics, including the recent COVID-19 outbreak. Insightful studies have uncovered the complexities of different functional networks of CD4 T cells (T helper 1 (Th1); Th2, Th17) and CD8 T cells (T cytotoxic; Tc), as well as B cell (BIgM, BIgG, BIgA and BIgE) subsets, during the response to vaccination. Both T and B cell subsets form central, peripheral, and tissue-resident subsets during vaccination. It has also become apparent that each vaccination forms a network of T regulatory subsets, namely CD4+ CD25+ Foxp3+ T regulatory (Treg) cells and interleukin-10 (IL-10)-producing CD4+ Foxp3- T regulatory 1 (Tr1), as well as many others, which shape the quality/quantity of vaccine-specific IgM, IgG, and IgA antibody production. These components are especially critical for immunocompromised patients, such as older individuals and allograft recipients, as their vaccination may be ineffective or less effective. This review focuses on considering how the pre- and post-vaccination Treg/Tr1 levels influence the vaccination efficacy. Experimental and clinical work has revealed that Treg/Tr1 involvement evokes different immune mechanisms in diminishing vaccine-induced cellular/humoral responses. Alternative steps may be considered to improve the vaccination response, such as increasing the dose, changing the delivery route, and/or repeated booster doses of vaccines. Vaccination may be combined with anti-CD25 (IL-2Rα chain) or anti-programmed cell death protein 1 (PD-1) monoclonal antibodies (mAb) to decrease the Tregs and boost the T/B cell immune response. All of these data and strategies for immunizations are presented and discussed, aiming to improve the efficacy of vaccination in humans and especially in immunocompromised and older individuals, as well as organ transplant patients.
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Affiliation(s)
- Stanislaw Stepkowski
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH 43614, USA; (D.B.); (B.M.)
| | - Dulat Bekbolsynov
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH 43614, USA; (D.B.); (B.M.)
| | - Jared Oenick
- Neurological Surgery, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA;
| | - Surina Brar
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH 43614, USA; (D.B.); (B.M.)
| | - Beata Mierzejewska
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH 43614, USA; (D.B.); (B.M.)
| | - Michael A. Rees
- Department of Urology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA; (M.A.R.); (O.E.)
| | - Obi Ekwenna
- Department of Urology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA; (M.A.R.); (O.E.)
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Gootjes C, Zwaginga JJ, Roep BO, Nikolic T. Defining Human Regulatory T Cells beyond FOXP3: The Need to Combine Phenotype with Function. Cells 2024; 13:941. [PMID: 38891073 PMCID: PMC11172350 DOI: 10.3390/cells13110941] [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: 02/28/2024] [Revised: 04/18/2024] [Accepted: 05/27/2024] [Indexed: 06/21/2024] Open
Abstract
Regulatory T cells (Tregs) are essential to maintain immune homeostasis by promoting self-tolerance. Reduced Treg numbers or functionality can lead to a loss of tolerance, increasing the risk of developing autoimmune diseases. An overwhelming variety of human Tregs has been described, based on either specific phenotype, tissue compartment, or pathological condition, yet the bulk of the literature only addresses CD25-positive and CD127-negative cells, coined by naturally occurring Tregs (nTregs), most of which express the transcription factor Forkhead box protein 3 (FOXP3). While the discovery of FOXP3 was seminal to understanding the origin and biology of nTregs, there is evidence in humans that not all T cells expressing FOXP3 are regulatory, and that not all Tregs express FOXP3. Namely, the activation of human T cells induces the transient expression of FOXP3, irrespective of whether they are regulatory or inflammatory effectors, while some induced T cells that may be broadly defined as Tregs (e.g., Tr1 cells) typically lack demethylation and do not express FOXP3. Furthermore, it is unknown whether and how many nTregs exist without FOXP3 expression. Several other candidate regulatory molecules, such as GITR, Lag-3, GARP, GPA33, Helios, and Neuropilin, have been identified but subsequently discarded as Treg-specific markers. Multiparametric analyses have uncovered a plethora of Treg phenotypes, and neither single markers nor combinations thereof can define all and only Tregs. To date, only the functional capacity to inhibit immune responses defines a Treg and distinguishes Tregs from inflammatory T cells (Teffs) in humans. This review revisits current knowledge of the Treg universe with respect to their heterogeneity in phenotype and function. We propose that it is unavoidable to characterize human Tregs by their phenotype in combination with their function, since phenotype alone does not unambiguously define Tregs. There is an unmet need to align the expression of specific markers or combinations thereof with a particular suppressive function to coin functional Treg entities and categorize Treg diversity.
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Affiliation(s)
- Chelsea Gootjes
- Laboratory of Immunomodulation and Regenerative Cell Therapy, Department of Internal Medicine, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (J.J.Z.); (T.N.)
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Pishel I. Immune system rejuvenation—approaches and real achievements. EXPLORATION OF IMMUNOLOGY 2023:325-340. [DOI: 10.37349/ei.2023.00105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/17/2023] [Indexed: 01/03/2025]
Abstract
Interest in the mechanisms of aging of the immune system has not faded over the past 100 years, and it is caused by the immune-mediated development of age-related pathology, including autoimmune organ damage, reduced vaccination efficiency, atherosclerosis, the development of cardiovascular pathology, etc. In contrast to many other organs and systems, the immune system aging begins at an early age and has more pronounced changes that lead to the development of secondary pathology, which significantly affects life expectancy. But an effective strategy to restore immune function has not been developed yet. During this time, the mechanisms of age-related dysfunction of organs and cells of both the adaptive and innate immune systems were studied in detail—thymus involution, a decrease in the potential of hematopoietic stem cells, impaired differentiation and functions of immunocompetent cells, as well as the ways of their interaction. Numerous potential therapeutic targets have been identified and various approaches have been used to implement such therapeutic interventions. The review is devoted to replacement therapy using transplantation of hematopoietic stem cells (HSCs) and young lymphoid cells and tissues, cellular and systemic factor exchange in heterochronic parabiosis, and some other widely used life extension approaches. It has been proven that cell therapy using young cells to rejuvenate the old immune system, unfortunately, often turns out to be ineffective because it does not eliminate the root cause of age-related changes. The phenomenon of inflamm-aging that develops with age can significantly affect both the aging of the organism in general and the functioning of immunocompetent cells in particular. Therefore, the most promising direction in the restoration of immune functions during aging is systemic approaches that have a complex effect on the organism as a whole and can slow down the aging process.
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Affiliation(s)
- Iryna Pishel
- Lab Applied Pharmacology and Toxicology, Bienta/Enamine Ltd, 02094 Kyiv, Ukraine
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Pozo-Balado MDM, Bulnes-Ramos Á, Olivas-Martínez I, Garrido-Rodríguez V, Lozano C, Álvarez-Ríos AI, Sánchez-Sánchez B, Sánchez-Bejarano E, Maldonado-Calzado I, Martín-Lara JM, Santamaría JA, Bernal R, González-Escribano MF, Leal M, Pacheco YM. Higher plasma levels of thymosin-α1 are associated with a lower waning of humoral response after COVID-19 vaccination: an eight months follow-up study in a nursing home. Immun Ageing 2023; 20:9. [PMID: 36879319 PMCID: PMC9986663 DOI: 10.1186/s12979-023-00334-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/23/2023] [Indexed: 03/08/2023]
Abstract
BACKGROUND Older people achieve lower levels of antibody titers than younger populations after Covid-19 vaccination and show a marked waning humoral immunity over time, likely due to the senescence of the immune system. Nevertheless, age-related predictive factors of the waning humoral immune response to the vaccine have been scarcely explored. In a cohort of residents and healthcare workers from a nursing home that had received two doses of the BNT162b2 vaccine, we measured specific anti-S antibodies one (T1), four (T4), and eight (T8) months after receiving the second dose. Thymic-related functional markers, including thymic output, relative telomere length, and plasma thymosin-α1 levels, as well as immune cellular subsets, and biochemical and inflammatory biomarkers, were determined at T1, and tested for their associations with the magnitude of the vaccine response (T1) and the durability of such response both, at the short- (T1-T4) and the long-term (T1-T8). We aimed to identify age-related factors potentially associated with the magnitude and persistence of specific anti-S immunoglobulin G (IgG)-antibodies after COVID-19 vaccination in older people. RESULTS Participants (100% men, n = 98), were subdivided into three groups: young (< 50 years-old), middle-age (50-65 years-old), and older (≥65 years-old). Older participants achieved lower antibody titers at T1 and experienced higher decreases in both the short- and long-term. In the entire cohort, while the magnitude of the initial response was mainly associated with the levels of homocysteine [β (95% CI); - 0.155 (- 0.241 to - 0.068); p = 0.001], the durability of such response at both, the short-term and the long-term were predicted by the levels of thymosin-α1 [- 0.168 (- 0.305 to - 0.031); p = 0.017, and - 0.123 (- 0.212 to - 0.034); p = 0.008, respectively]. CONCLUSIONS Higher plasma levels of thymosin-α1 were associated with a lower waning of anti-S IgG antibodies along the time. Our results suggest that plasma levels of thymosin-α1 could be used as a biomarker for predicting the durability of the responses after COVID-19 vaccination, possibly allowing to personalize the administration of vaccine boosters.
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Affiliation(s)
- María Del Mar Pozo-Balado
- Immunology Laboratory, Institute of Biomedicine of Seville (IBiS), Immunology Service, Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Ave. Manuel Siurot s/n, 41013, Seville, Spain
| | - Ángel Bulnes-Ramos
- Immunology Laboratory, Institute of Biomedicine of Seville (IBiS), Immunology Service, Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Ave. Manuel Siurot s/n, 41013, Seville, Spain
| | - Israel Olivas-Martínez
- Immunology Laboratory, Institute of Biomedicine of Seville (IBiS), Immunology Service, Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Ave. Manuel Siurot s/n, 41013, Seville, Spain
| | - Vanesa Garrido-Rodríguez
- Immunology Laboratory, Institute of Biomedicine of Seville (IBiS), Immunology Service, Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Ave. Manuel Siurot s/n, 41013, Seville, Spain
| | - Carmen Lozano
- Microbiology Service, Virgen del Rocío University Hospital (HUVR), Seville, Spain
| | - Ana I Álvarez-Ríos
- Biochemistry Service, Virgen del Rocío University Hospital (HUVR), Seville, Spain
| | | | | | | | | | | | - Rafael Bernal
- Hogar Residencia de la Santa Caridad, Seville, Spain
| | - María Francisca González-Escribano
- Immunology Laboratory, Institute of Biomedicine of Seville (IBiS), Immunology Service, Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Ave. Manuel Siurot s/n, 41013, Seville, Spain.,Immunology Service, Virgen del Rocío University Hospital (HUVR), Seville, Spain
| | - Manuel Leal
- Hogar Residencia de la Santa Caridad, Seville, Spain.,Internal Medicine Service, Viamed Hospital, Santa Ángela de la Cruz, Seville, Spain
| | - Yolanda M Pacheco
- Immunology Laboratory, Institute of Biomedicine of Seville (IBiS), Immunology Service, Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Ave. Manuel Siurot s/n, 41013, Seville, Spain.
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Verschoor CP, Picard E, Andrew MK, Haynes L, Loeb M, Pawelec G, Kuchel GA. NK- and T-cell granzyme B and K expression correlates with age, CMV infection and influenza vaccine-induced antibody titres in older adults. FRONTIERS IN AGING 2023; 3:1098200. [PMID: 36685324 PMCID: PMC9849551 DOI: 10.3389/fragi.2022.1098200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 12/20/2022] [Indexed: 01/06/2023]
Abstract
Granzymes are a family of serine-proteases that act as critical mediators in the cytolytic and immunomodulatory activities of immune cells such as CD8+ T-cells and natural killer (NK) cells. Previous work indicates that both granzyme B (GZB) and K (GZK) are increased with age in CD8+ T-cells, and in the case of GZB, contribute to dysfunctional immune processes observed in older adults. Here, we sought to determine how GZB and GZK expression in NK-cells, and CD4+, CD8+, and gamma-delta T-cells, quantified in terms of positive cell frequency and mean fluorescence intensity (MFI), differed with age, age-related health-traits and the antibody response to high-dose influenza vaccine. We found that the frequency and MFI of GZB-expressing NK-cells, and CD8+ and Vδ1+ T-cells, and GZK-expressing CD8+ T-cells was significantly higher in older (66-97 years old; n = 75) vs. younger (24-37 years old; n = 10) adults by up to 5-fold. There were no significant associations of GZB/GZK expression with sex, frailty or plasma levels of TNF or IL-6 in older adults, but those who were seropositive for cytomegalovirus (CMV) exhibited significantly higher frequencies of GZB+ NK-cells, and CD4+, CD8+ and Vδ1+ T-cells, and GZK+ CD8+ T-cells (Cohen's d = .5-1.5). Pre-vaccination frequencies of GZB+ NK-cells were positively correlated with vaccine antibody responses against A/H3N2 (d = .17), while the frequencies of GZK+ NK and CD8+ T-cells were inversely associated with A/H1N1 (d = -0.18 to -0.20). Interestingly, GZK+ NK-cell frequency was inversely correlated with pre-vaccination A/H1N1 antibody titres, as well as those measured over the previous 4 years, further supporting a role for this subset in influencing vaccine antibody-responses. These findings further our understanding of how granzyme expression in different lymphoid cell-types may change with age, while suggesting that they influence vaccine responsiveness in older adults.
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Affiliation(s)
- Chris P. Verschoor
- Health Sciences North Research Institute, Sudbury, ON, Canada,Northern Ontario School of Medicine, Sudbury, ON, Canada,*Correspondence: Chris P. Verschoor,
| | - Emilie Picard
- Health Sciences North Research Institute, Sudbury, ON, Canada
| | | | - Laura Haynes
- UConn Center on Aging, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Mark Loeb
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Graham Pawelec
- Health Sciences North Research Institute, Sudbury, ON, Canada,Department of Immunology, University of Tübingen, Tübingen, Germany
| | - George A. Kuchel
- UConn Center on Aging, University of Connecticut School of Medicine, Farmington, CT, United States
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Kato G, Nakajima H, Suzuki K, Kanzawa Y, Nakayasu C, Taguchi K, Kurata O, Sano M. Decreased resistance to bacterial cold-water disease and excessive inflammatory response in ayu ( Plecoglossus altivelis) reared at high water temperature. Front Immunol 2023; 14:1101491. [PMID: 36817479 PMCID: PMC9931725 DOI: 10.3389/fimmu.2023.1101491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/18/2023] [Indexed: 02/05/2023] Open
Abstract
Introduction Temporal elevation of water temperature positively affects immune activity and disease resistance in poikilothermic teleost fish. The ayu, Plecoglossus altivelis, an important fish species for Japanese freshwater fisheries, is usually produced under higher water temperatures than the natural conditions to facilitate rapid growth. However, it has been reported that rearing fish at higher water temperatures inhibits the development of the thymus, suggesting that resistance to infectious diseases is reduced in ayu reared at higher water temperatures. Here, we show that decreased resistance to bacterial cold-water disease and excessive inflammatory responses occurred in ayu reared at 22°C compared with those reared at lower temperatures. Methods Ayu larvae were reared at 12°C, 15°C and 22°C for 77 days and fed 3% of their body weight. Thymus index and condition factor was calculated after the fish rearing. Then, ayu reared at the different temperatures were challenged with Flavobacterium psychrophilum and the fish were sampled for histopathology and gene expression analyses. Further, the fish were vaccinated with formalin-killed F. psychrophilum and continuously reared at the three different water temperatures. Serum antibody titer was determined by ELISA and cumulative mortality in each group was recorded after the bacterial challenge. Results Ayu reared at 22°C showed a significantly lower thymus index and higher condition factor than those reared at lower temperatures. Infiltrated leukocytes and many melanin pigments were frequently observed in the adipose tissues and spleens of ayu reared at 22°C, respectively, but not in those reared at 12°C. The gene expression levels of inflammatory cytokines such as IL-1β, IL-8 and TNFα in the spleen were significantly higher in the 22°C group than in the 12°C group. The cumulative survival rate after challenge with Flavobacterium psychrophilum was 51.7%, 40.0% and 13.3% in the 12°C, 15°C and 22°C groups, respectively. The relative percent survival values of vaccinated fish reared at 15°C and 22°C groups were lower than those reared at 12°C. Moreover, the specific antibody titer of the vaccinated fish was the lowest in the 22°C group and the highest in the 12°C group. Discussion These results suggest that rearing the fish under high water temperature causes excessive inflammatory responses similar to metabolic inflammation in human obesity, resulting in a decrease of disease resistance. In addition, thymic involution induced by higher water temperature probably leads the poor response to vaccination. The present study provides insights into the physiological and immunological changes of fish under global warming.
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Affiliation(s)
- Goshi Kato
- Laboratory of Fish Pathology, The Marine Faculty of Bioresources Phylum, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Hayato Nakajima
- Laboratory of Fish Pathology, The Marine Faculty of Bioresources Phylum, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Kyuma Suzuki
- Gunma Prefectural Fisheries Experiment Station, Gunma, Japan
| | - Yuhei Kanzawa
- Gunma Prefectural Fisheries Experiment Station, Gunma, Japan
| | - Chihaya Nakayasu
- Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie, Japan
| | - Kosei Taguchi
- Laboratory of Aquatic Medicine, School of Veterinary Medicine, Faculty of Veterinary Medical Science, Nippon Veterinary and Life Science University, Tokyo, Japan
| | - Osamu Kurata
- Laboratory of Aquatic Medicine, School of Veterinary Medicine, Faculty of Veterinary Medical Science, Nippon Veterinary and Life Science University, Tokyo, Japan
| | - Motohiko Sano
- Laboratory of Fish Pathology, The Marine Faculty of Bioresources Phylum, Tokyo University of Marine Science and Technology, Tokyo, Japan
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Palatella M, Guillaume SM, Linterman MA, Huehn J. The dark side of Tregs during aging. Front Immunol 2022; 13:940705. [PMID: 36016952 PMCID: PMC9398463 DOI: 10.3389/fimmu.2022.940705] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
In the last century, we have seen a dramatic rise in the number of older persons globally, a trend known as the grey (or silver) tsunami. People live markedly longer than their predecessors worldwide, due to remarkable changes in their lifestyle and in progresses made by modern medicine. However, the older we become, the more susceptible we are to a series of age-related pathologies, including infections, cancers, autoimmune diseases, and multi-morbidities. Therefore, a key challenge for our modern societies is how to cope with this fragile portion of the population, so that everybody could have the opportunity to live a long and healthy life. From a holistic point of view, aging results from the progressive decline of various systems. Among them, the distinctive age-dependent changes in the immune system contribute to the enhanced frailty of the elderly. One of these affects a population of lymphocytes, known as regulatory T cells (Tregs), as accumulating evidence suggest that there is a significant increase in the frequency of these cells in secondary lymphoid organs (SLOs) of aged animals. Although there are still discrepancies in the literature about modifications to their functional properties during aging, mounting evidence suggests a detrimental role for Tregs in the elderly in the context of bacterial and viral infections by suppressing immune responses against non-self-antigens. Interestingly, Tregs seem to also contribute to the reduced effectiveness of immunizations against many pathogens by limiting the production of vaccine-induced protective antibodies. In this review, we will analyze the current state of understandings about the role of Tregs in acute and chronic infections as well as in vaccination response in both humans and mice. Lastly, we provide an overview of current strategies for Treg modulation with potential future applications to improve the effectiveness of vaccines in older individuals.
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Affiliation(s)
- Martina Palatella
- Department Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | | | - Jochen Huehn
- Department Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
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Gal3 Plays a Deleterious Role in a Mouse Model of Endotoxemia. Int J Mol Sci 2022; 23:ijms23031170. [PMID: 35163089 PMCID: PMC8835800 DOI: 10.3390/ijms23031170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/14/2022] [Accepted: 01/15/2022] [Indexed: 12/27/2022] Open
Abstract
Lipopolysaccharide (LPS)-induced endotoxemia induces an acute systemic inflammatory response that mimics some important features of sepsis, the disease with the highest mortality rate worldwide. In this work, we have analyzed a murine model of endotoxemia based on a single intraperitoneal injection of 5 mg/kg of LPS. We took advantage of galectin-3 (Gal3) knockout mice and found that the absence of Gal3 decreased the mortality rate oflethal endotoxemia in the first 80 h after the administration of LPS, along with a reduction in the tissular damage in several organs measured by electron microscopy. Using flow cytometry, we demonstrated that, in control conditions, peripheral immune cells, especially monocytes, exhibited high levels of Gal3, which were early depleted in response to LPS injection, thus suggesting Gal3 release under endotoxemia conditions. However, serum levels of Gal3 early decreased in response to LPS challenge (1 h), an indication that Gal3 may be extravasated to peripheral organs. Indeed, analysis of Gal3 in peripheral organs revealed a robust up-regulation of Gal3 36 h after LPS injection. Taken together, these results demonstrate the important role that Gal3 could play in the development of systemic inflammation, a well-established feature of sepsis, thus opening new and promising therapeutic options for these harmful conditions.
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Regulatory T cells and vaccine effectiveness in older adults. Challenges and prospects. Int Immunopharmacol 2021; 96:107761. [PMID: 34162139 DOI: 10.1016/j.intimp.2021.107761] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/24/2021] [Accepted: 05/04/2021] [Indexed: 12/21/2022]
Abstract
Since the discovery of lymphocytes with immunosuppressive activity, increasing interest has arisen in their possible influence on the immune response induced by vaccines. Regulatory T cells (Tregs) are essential for maintaining peripheral tolerance, preventing autoimmune diseases, and limiting chronic inflammatory diseases. However, they also limit beneficial immune responses by suppressing anti-infectious and anti-tumor immunity. Mounting evidence suggests that Tregs are involved, at least in part, in the low effectiveness of immunization against various diseases where it has been difficult to obtain protective vaccines. Interestingly, increased activity of Tregs is associated with aging, suggesting a key role for these cells in the lower vaccine effectiveness observed in older people. In this review, we analyze the impact of Tregs on vaccination, with a focus on older adults. Finally, we address an overview of current strategies for Tregs modulation with potential application to improve the effectiveness of future vaccines targeting older populations.
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Zheng J, Meyerholz D, Wong LYR, Gelb M, Murakami M, Perlman S. Coronavirus-specific antibody production in middle-aged mice requires phospholipase A2G2D. J Clin Invest 2021; 131:147201. [PMID: 34060490 PMCID: PMC8266207 DOI: 10.1172/jci147201] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 04/14/2021] [Indexed: 01/18/2023] Open
Abstract
Worse outcomes occur in aged compared with young populations after infections with respiratory viruses, including pathogenic coronaviruses (SARS-CoV, MERS-CoV, and SARS-CoV-2), and are associated with a suboptimal lung milieu ("inflammaging"). We previously showed that a single inducible phospholipase, PLA2G2D, is associated with a proresolving/antiinflammatory response in the lungs, and increases with age. Survival was increased in naive Pla2g2d-/- mice infected with SARS-CoV resulting from augmented respiratory dendritic cell (rDC) activation and enhanced priming of virus-specific T cells. Here, in contrast, we show that intranasal immunization provided no additional protection in middle-aged Pla2g2d-/- mice infected with any of the 3 pathogenic human coronaviruses because virtually no virus-specific antibodies or follicular helper CD4+ T (Tfh) cells were produced. Using MERS-CoV-infected mice, we found that these effects did not result from T or B cell intrinsic factors. Rather, they resulted from enhanced, and ultimately, pathogenic rDC activation, as manifested most prominently by enhanced IL-1β expression. Wild-type rDC transfer to Pla2g2d-/- mice in conjunction with partial IL-1β blockade reversed this defect and resulted in increased virus-specific antibody and Tfh responses. Together, these results indicate that PLA2G2D has an unexpected role in the lungs, serving as an important modulator of rDC activation, with protective and pathogenic effects in respiratory coronavirus infections and immunization, respectively.
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Affiliation(s)
- Jian Zheng
- Department of Microbiology and Immunology and
| | | | | | - Michael Gelb
- Departments of Chemistry and Biochemistry, University of Washington, Seattle, Washington, USA
| | - Makoto Murakami
- Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Garrido-Rodríguez V, Herrero-Fernández I, Castro MJ, Castillo A, Rosado-Sánchez I, Galvá MI, Ramos R, Olivas-Martínez I, Bulnes-Ramos Á, Cañizares J, Leal M, Pacheco YM. Immunological features beyond CD4/CD8 ratio values in older individuals. Aging (Albany NY) 2021; 13:13443-13459. [PMID: 34038386 PMCID: PMC8202849 DOI: 10.18632/aging.203109] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/17/2021] [Indexed: 12/02/2022]
Abstract
The CD4/CD8 T-cell ratio is emerging as a relevant marker of evolution for many pathologies and therapies. We aimed to explore immunological features beyond CD4/CD8 ratio values in older subjects (>65 years old) who were classified as having lower (<1.4), intermediate (1.4-2), or higher (>2) ratio values. The lower group showed a lower thymic output (sj/β-TREC ratio) and frequency of naïve T-cells, concomitant with increased mature T-cells. In these subjects, the CD4 T-cell subset was enriched in CD95+ but depleted of CD98+ cells. The regulatory T-cell (Treg) compartment was enriched in CTLA-4+ cells. The CD8 T-cell pool exhibited increased frequencies of CD95+ cells but decreased frequencies of integrin-β7+ cells. Interestingly, in the intermediate group, the CD4 pool showed greater differences than the CD8 pool, mostly for cellular senescence. Regarding inflammation, only hsCRP was elevated in the lower group; however, negative correlations between the CD4/CD8 ratio and β2-microglobulin and sCD163 were detected. These subjects displayed trends of more comorbidities and less independence in daily activities. Altogether, our data reveal different thymic output and immune profiles for T-cells across CD4/CD8 ratio values that can define immune capabilities, affecting health status in older individuals. Thus, the CD4/CD8 ratio may be used as an integrative marker of biological age.
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Affiliation(s)
- Vanesa Garrido-Rodríguez
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Seville, Spain
| | - Inés Herrero-Fernández
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Seville, Spain
| | - María José Castro
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Seville, Spain
| | - Ana Castillo
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Seville, Spain
| | - Isaac Rosado-Sánchez
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Seville, Spain
| | | | | | - Israel Olivas-Martínez
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Seville, Spain
| | - Ángel Bulnes-Ramos
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Seville, Spain
| | | | - Manuel Leal
- Immunovirology Unit, Internal Medicine Service, Viamed Hospital, Santa Ángela de la Cruz, Seville, Spain
| | - Yolanda María Pacheco
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital (HUVR)/CSIC/University of Seville, Seville, Spain
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12
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Rocamora-Reverte L, Melzer FL, Würzner R, Weinberger B. The Complex Role of Regulatory T Cells in Immunity and Aging. Front Immunol 2021; 11:616949. [PMID: 33584708 PMCID: PMC7873351 DOI: 10.3389/fimmu.2020.616949] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/07/2020] [Indexed: 12/20/2022] Open
Abstract
The immune system is a tightly regulated network which allows the development of defense mechanisms against foreign antigens and tolerance toward self-antigens. Regulatory T cells (Treg) contribute to immune homeostasis by maintaining unresponsiveness to self-antigens and suppressing exaggerated immune responses. Dysregulation of any of these processes can lead to serious consequences. Classically, Treg cell functions have been described in CD4+ T cells, but other immune cells also harbour the capacity to modulate immune responses. Regulatory functions have been described for different CD8+ T cell subsets, as well as other T cells such as γδT cells or NKT cells. In this review we describe the diverse populations of Treg cells and their role in different scenarios. Special attention is paid to the aging process, which is characterized by an altered composition of immune cells. Treg cells can contribute to the development of various age-related diseases but they are poorly characterized in aged individuals. The huge diversity of cells that display immune modulatory functions and the lack of universal markers to identify Treg make the expanding field of Treg research complex and challenging. There are still many open questions that need to be answered to solve the enigma of regulatory T cells.
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Affiliation(s)
- Lourdes Rocamora-Reverte
- Department of Immunology, Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria
| | - Franz Leonard Melzer
- Department of Immunology, Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria
| | - Reinhard Würzner
- Institute of Hygiene & Medical Microbiology, Department of Hygiene, Microbiology and Public Health, Medical University Innsbruck, Innsbruck, Austria
| | - Birgit Weinberger
- Department of Immunology, Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria
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13
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Bulut O, Kilic G, Domínguez-Andrés J, Netea MG. Overcoming immune dysfunction in the elderly: trained immunity as a novel approach. Int Immunol 2020; 32:741-753. [PMID: 32766848 PMCID: PMC7680842 DOI: 10.1093/intimm/dxaa052] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022] Open
Abstract
People with advanced age have a higher susceptibility to infections and exhibit increased mortality and morbidity as the ability of the immune system to combat infections decreases with age. While innate immune cells display functional defects such as decreased phagocytosis, chemotaxis and cytokine production, adaptive immune cells exhibit reduced receptor diversity, defective antibody production and a sharp decline in naive cell populations. Successful responses to vaccination in the elderly are critical to prevent common infections such as influenza and pneumonia, but vaccine efficacy decreases in older individuals compared with young adults. Trained immunity is a newly emerging concept that showed that innate immune cells possess non-specific immunological memory established through epigenetic and metabolic reprogramming upon encountering certain pathogenic stimuli. Clinical studies suggest that trained immunity can be utilized to enhance immune responses against infections and improve the efficiency of vaccinations in adults; however, how trained immunity responses are shaped with advanced age is still an open question. In this review, we provide an overview of the age-related changes in the immune system with a focus on innate immunity, discuss current vaccination strategies for the elderly, present the concept of trained immunity and propose it as a novel approach to enhance responses against infections and vaccinations in the elderly population.
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Affiliation(s)
- Ozlem Bulut
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, GA Nijmegen, The Netherlands
| | - Gizem Kilic
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, GA Nijmegen, The Netherlands
| | - Jorge Domínguez-Andrés
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, GA Nijmegen, The Netherlands
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, GA Nijmegen, The Netherlands
- Department of Genomics and Immunoregulation, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
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