scholarly journals 669 Lactate uptake through MCT11, a novel monocarboxylate transporter, enforces dysfunction in terminally exhausted T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A697-A697
Author(s):  
Ronal Peralta ◽  
Greg Delgoffe
Keyword(s):  
T Cells ◽  
Lactic Acid ◽  
Tumor Burden ◽  
B16 Melanoma ◽  
T Cell Subsets ◽  
Monocarboxylate Transporter ◽  
Acid Uptake ◽  
Ribonucleoprotein Complexes ◽  
Lactate Uptake ◽  
Marker Expression

BackgroundUpon infiltration into tumors, T cells experiencing persistent antigen stimulation progressively differentiate into a state of dysfunction, known as exhaustion. Exhausted T cells are characterized by the sustained upregulation of co-inhibitory molecules and reduced effector cytokine production. Additionally, exhausted T cells exist in a state of metabolic dysfunction in the tumor microenvironment (TME), due to disrupted mitochondrial biogenesis, hypoxia and lack of metabolites. Highly glycolytic tumor and stromal cells outcompete T cells for glucose, and secrete lactate into the TME, acidifying the extracellular space. Recent studies have shown lactate can be metabolized by tumor infiltrating Tregs and macrophages. We hypothesized that CD8+ tumor-infiltrating lymphocytes (TIL) may also take up lactate as an alternative carbon source to meet their metabolic demands.MethodsFor lactate uptake experiments, B16 melanoma single cell suspensions from B6 mice were loaded with the pH sensitive dye pHrodo, then pulsed with 5µM lactic acid. MCT11 KO OT-I T cells were generated via transfection of Slc16a11 sgRNA-Cas9 ribonucleoprotein complexes, and adoptively transferred into B16-OVA bearing mice.ResultsRNA sequencing and flow cytometry data from CD8+ T cell subsets in the TME revealed MCT11 (encoded by Slc16a11), a monocarboxylate transporter (MCT) only recently discovered, to be highly and uniquely expressed in terminally exhausted T cells (Tex). As lactate is an abundant monocarboxylate in tumors, we asked whether MCT11 supports lactate uptake into Tex cells. Antibody blockade of MCT11 resulted in reduced lactic acid uptake, but whether lactic acid promoted or inhibited effector function. Intriguingly, overexpression of MCT11 in OT-I T cells adoptively transferred into B16-OVA bearing mice resulted in accelerated exhaustion: increased co-inhibitory marker expression and decreased TNFa and IFN production. Conversely, knockdown of MCT11 in the same model resulted in decreased co-inhibitory marker expression and increased TNFa and IFN production. Further, MCT11 KO OT-I T cells used therapeutically had decreased tumor burden over mice treated with control OT-I T cells. As MCT11's uptake function was blocked with an antibody, we also used the antibody therapeutically, revealing that single-agent MCT11 antibody treatment reduced tumor burden and increased survival in B16 melanoma bearing mice.ConclusionsOur data support a model where exhausted CD8+ T cells upregulate MCT11, which renders them sensitive to toxic lactic acid in the TME. Our data suggest MCT11 could be deleted on therapeutic T cells or blocked using an antibody on endogenous T cells to render exhausted T cells impervious to lactic acid such and promote tumor eradication.

549 Characterizing double positive T cells in the tumor microenvironment: a tale of promiscuous cell fates

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A586-A586
Author(s):  
Sara Schad ◽  
Andrew Chow ◽  
Heng Pan ◽  
Levi Mangarin ◽  
Roberta Zappasodi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Cd8 T Cells ◽  
Human Melanoma ◽  
B16 Melanoma ◽  
T Cell Subsets ◽  
Double Positive ◽  
Cell Fates ◽  
Single Positive

BackgroundCD4 and CD8 T cells are genetically and functionally distinct cell subsets of the adaptive immune system that play pivotal roles in immune surveillance and disease control. During development in the thymus, transcription factors ThPOK and Runx3 regulate the differentiation and maturation of these two lineages into single positive T cells that enter the periphery with mutually exclusive expression of either the CD4 or CD8 co-receptor.1–2 Despite our expectation that these two cell fates are fixed, mature CD4+CD8+ double positive (DP) T cells have been described in the context of numerous immunological responses, including cancer, but their molecular and functional properties and therapeutic relevance remain controversial and largely unknown.3–5MethodsOur lab has identified and characterized a heterogenous DP T cell population in murine and human melanoma tumors comprised of CD4 and CD8 T cells re-expressing the opposite co-receptor and a parallel uptake in the opposite cell type’s phenotype and function. Using CD4 (Trp1) and CD8 (Pmel) transgenic TCR T cells specific to B16 melanoma antigens gp75 and gp100 respectively, we demonstrate the re-expression of the opposite co-receptor following adoptive T cell transfer in B16 melanoma tumor bearing mice.ResultsSpecifically, up to 50% of transferred CD4 Trp1 T cells will re-express CD8 to become a DP T cell in the tumor microenvironment. Further, these CD4 derived DP T cells upregulate CD8 lineage regulator Runx3 and cytolytic genes Gzmb, Gzmk, and Prf1 to become potent cytotoxic T cells. Alternatively, a subset of CD8 Pmel T cells differentiate into DP T cells characterized by the increased expression of CD4, ThPOK, and regulatory marker FoxP3 (figure 1). In addition, we utilized 10x single cell and ATAC sequencing to further characterize these divergent DP T cell populations among open repertoire T cells isolated from murine and human melanoma tumors.ConclusionsOur findings highlight the capability of single positive T cells to differentiate in response to antigen and local stimuli into novel T cell subsets with polyfunctional characteristics. The resulting cell subsets will potentially affect the tumor microenvironment in distinct ways. Our studies may inform therapeutic approaches to identify antigen specific T cells as well as innovative signaling pathways to target when genetically engineering T cells to optimize cytotoxic function in the setting of adoptive cell therapy.Ethics ApprovalThe human biospecimen analyses were approved by Memorial Sloan Kettering Cancer Center IRB #06-107ReferencesEllmeier W, Haust L & Tschismarov R. Transcriptional control of CD4 and CD8 coreceptor expression during T cell development. Cell Mol Life Sci 2013;70:4537–4553.Luckey MA, et al. The transcription factor ThPOK suppresses Runx3 and imposes CD4+ lineage fate by inducing the SOCS suppressors of cytokine signaling. Nature Immunology 2014; 15, 638–645.Bohner P, et al. Double positive CD4(+)CD8(+) T Cells are enriched in urological cancers and favor T Helper-2 polarization. Front Immunol 2019; 10, 622.Nascimbeni M, Shin E-C, Chiriboga L, Kleiner DE & Rehermann B. Peripheral CD4(+)CD8(+) T cells are differentiated effector memory cells with antiviral functions. Blood 2004;104:478–486.Nishida K, et al. Clinical importance of the expression of CD4+CD8+ T cells in renal cell carcinoma. Int Immunol 2020;32:347–357.

The transport of carboxylic acids and important role of the Jen1p transporter during the development of yeast colonies

2013 ◽  
Vol 454 (3) ◽  
pp. 551-558 ◽  
Author(s):  
Sandra Paiva ◽  
Dita Strachotová ◽  
Helena Kučerová ◽  
Otakar Hlaváček ◽  
Sandra Mota ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Lactic Acid ◽  
Cell Metabolism ◽  
Colony Development ◽  
Acid Uptake ◽  
Uptake Capacity ◽  
Solid Substrates ◽  
Lactate Uptake ◽  
Pass Through ◽  
Developmental Phases

On solid substrates, yeast colonies pass through distinct developmental phases characterized by the changes in pH of their surroundings from acidic to nearly alkaline and vice versa. At the beginning of the alkali phase colonies start to produce ammonia, which functions as a quorum-sensing molecule inducing the reprogramming of cell metabolism. Such reprogramming includes, among others, the activation of several plasma membrane transporters and is connected with colony differentiation. In the present study, we show that colony cells can use two transport mechanisms to import lactic acid: a ‘saturable’ component of the transport, which requires the presence of a functional Jen1p transporter, and a ‘non-saturable’ component (diffusion) that is independent of Jen1p. During colony development, the efficiency of both transport components changes similarly in central and outer colonial cells. Although the lactate uptake capacity of central cells gradually decreases during colony development, the lactate uptake capacity of outer cells peaks during the alkali phase and is also kept relatively high in the second acidic phase. This lactate uptake profile correlates with the localization of the Jen1p transporter to the plasma membrane of colony cells. Both lactic acid uptake mechanisms are diminished in sok2 colonies where JEN1 expression is decreased. The Sok2p transcription factor may therefore be involved in the regulation of non-saturable lactic acid uptake in yeast colonies.

Peripheral and tumor immune correlates in patients with advanced melanoma treated with combination nivolumab (anti-PD-1, BMS-936558, ONO-4538) and ipilimumab.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 3003-3003 ◽  
Author(s):  
Margaret K. Callahan ◽  
Christine E. Horak ◽  
Michael A. Curran ◽  
Travis Hollman ◽  
David A. Schaer ◽  
...  
Keyword(s):  
T Cells ◽  
Combination Therapy ◽  
Objective Response ◽  
Predictive Biomarkers ◽  
Tumor Burden ◽  
T Cell Subsets ◽  
Phase Iii ◽  
Tumor Cell Membrane ◽  
Phenotypic Changes ◽  
Immune Correlates

3003^ Background: Nivolumab and ipilimumab are fully human monoclonal antibodies that block the immune checkpoint receptors PD-1 and CTLA-4, respectively. In a multi-cohort, phase I study of nivolumab/ipilimumab combination therapy in melanoma patients (pts), objective response rates up to 47% were observed (NCT01024231). Putative predictive biomarkers from peripheral blood (PB) or tumor, including tumor PD-L1 expression, absolute lymphocyte count (ALC) and PB myeloid derived suppressor cells (MDSC) were evaluated. Pharmacodynamic changes in activated and effector T cells were also assessed. Methods: Tumor PD-L1 membrane expression was assessed in archival FFPE specimens by immunohistochemistry (28-8 PD-L1 antibody). ALC was measured in serial PB samples; changes in the percentage, number and phenotype of activated CD4+ and CD8+T cells and MDSC were characterized by flow cytometry. Results: PD-L1 expression was seen in 37% (10/27) of pts, using a cut-off of 5% tumor cell membrane staining. Objective responses (OR) were seen in pts with both PD-L1 negative (8/17) and PD-L1 positive (4/10) tumors. Relative to baseline, a rise in ALC was not detected, but phenotypic changes in PB T-cell subsets, including increases in the percentage of CD4 and CD8 expressing HLA-DR, ICOS and/or Ki67 were seen with combination therapy. Low ALC (<1.0 at wk 6-7) did not preclude OR as 3 of 12 pts with low ALC responded. Of pts evaluated, OR with ≥80% reduction in tumor burden at 12 wk were seen in pts with a low frequency of pretreatment PB MDSC (3/7) but no OR were seen in pts with high MDSC (0/6). Conclusions: In this small subset of pts,OR were seen independent of PD-L1 or ALC status in contrast to prior observations with nivolumab or ipilimumab, respectively. Thus, the immune response generated by combination therapy may have unique features compared to either monotherapy. The relationship between frequency of PB MDSC and reduction in tumor burden will be further explored. Further efforts in this study and in future phase III randomized studies will investigate these and other phenotypic changes in immune cell populations and their relationship to patterns of clinical activity. Clinical trial information: NCT01024231.

scholarly journals Lactic Acid Permeability of Aquaporin-9 Enables Cytoplasmic Lactate Accumulation via an Ion Trap

Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Katharina Geistlinger ◽  
Jana D. R. Schmidt ◽  
Eric Beitz
Keyword(s):  
Lactic Acid ◽  
Ion Trap ◽  
Monocarboxylate Transporter ◽  
Acid Uptake ◽  
Monocarboxylate Transporter 1 ◽  
Low Concentrations ◽  
Aquaporin 9 ◽  
Uptake Rates ◽  
Ph Conditions ◽  
External Ph

(1) Background: Human aquaporin-9 (AQP9) conducts several small uncharged metabolites, such as glycerol, urea, and lactic acid. Certain brain tumors were shown to upregulate AQP9 expression, and the putative increase in lactic acid permeability was assigned to severity. (2) Methods: We expressed AQP9 and human monocarboxylate transporter 1 (MCT1) in yeast to determine the uptake rates and accumulation of radiolabeled l-lactate/l-lactic acid in different external pH conditions. (3) Results: The AQP9-mediated uptake of l-lactic acid was slow compared to MCT1 at neutral and slightly acidic pH, due to low concentrations of the neutral substrate species. At a pH corresponding to the pKa of l-lactic acid, uptake via AQP9 was faster than via MCT1. Substrate accumulation was fundamentally different between AQP9 and MCT1. With MCT1, an equilibrium was reached, at which the intracellular and extracellular l-lactate/H+ concentrations were balanced. Uptake via AQP9 was linear, theoretically yielding orders of magnitude of higher substrate accumulation than MCT1. (4) Conclusions: The selectivity of AQP9 for neutral l-lactic acid establishes an ion trap for l-lactate after dissociation. This may be physiologically relevant if the transmembrane proton gradient is steep, and AQP9 acts as the sole uptake path on at least one side of a polarized cell.

Inhibitory effect of tumor cell–derived lactic acid on human T cells

Blood ◽  
2007 ◽  
Vol 109 (9) ◽  
pp. 3812-3819 ◽  
Author(s):  
Karin Fischer ◽  
Petra Hoffmann ◽  
Simon Voelkl ◽  
Norbert Meidenbauer ◽  
Julia Ammer ◽  
...  
Keyword(s):  
T Cells ◽  
Lactic Acid ◽  
Cytokine Production ◽  
Lactic Acid Production ◽  
Recovery Period ◽  
Monocarboxylate Transporter ◽  
Immune Functions ◽  
Tumor Spheroids ◽  
Activated T Cells ◽  
Monocarboxylate Transporter 1

Abstract A characteristic feature of tumors is high production of lactic acid due to enhanced glycolysis. Here, we show a positive correlation between lactate serum levels and tumor burden in cancer patients and examine the influence of lactic acid on immune functions in vitro. Lactic acid suppressed the proliferation and cytokine production of human cytotoxic T lymphocytes (CTLs) up to 95% and led to a 50% decrease in cytotoxic activity. A 24-hour recovery period in lactic acid–free medium restored CTL function. CTLs infiltrating lactic acid–producing multicellular tumor spheroids showed a reduced cytokine production. Pretreatment of tumor spheroids with an inhibitor of lactic acid production prevented this effect. Activated T cells themselves use glycolysis and rely on the efficient secretion of lactic acid, as its intracellular accumulation disturbs their metabolism. Export by monocarboxylate transporter-1 (MCT-1) depends on a gradient between cytoplasmic and extracellular lactic acid concentrations and consequently, blockade of MCT-1 resulted in impaired CTL function. We conclude that high lactic acid concentrations in the tumor environment block lactic acid export in T cells, thereby disturbing their metabolism and function. These findings suggest that targeting this metabolic pathway in tumors is a promising strategy to enhance tumor immunogenicity.

scholarly journals Recruitment and Expansion of Tregs Cells in the Tumor Environment—How to Target Them?

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1850
Author(s):  
Justine Cinier ◽  
Margaux Hubert ◽  
Laurie Besson ◽  
Anthony Di Roio ◽  
Céline Rodriguez ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Tumor Microenvironment ◽  
Poor Prognosis ◽  
T Cell Subsets ◽  
Cd4 T Cell ◽  
Major Function ◽  
Normal Tissues ◽  
Tumor Environment ◽  
Plastic Transformation

Regulatory T cells (Tregs) are present in a large majority of solid tumors and are mainly associated with a poor prognosis, as their major function is to inhibit the antitumor immune response contributing to immunosuppression. In this review, we will investigate the mechanisms involved in the recruitment, amplification and stability of Tregs in the tumor microenvironment (TME). We will also review the strategies currently developed to inhibit Tregs’ deleterious impact in the TME by either inhibiting their recruitment, blocking their expansion, favoring their plastic transformation into other CD4+ T-cell subsets, blocking their suppressive function or depleting them specifically in the TME to avoid severe deleterious effects associated with Treg neutralization/depletion in the periphery and normal tissues.

scholarly journals Cryopreservation of Whole Tumor Biopsies from Rectal Cancer Patients Enable Phenotypic and In Vitro Functional Evaluation of Tumor-Infiltrating T Cells

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2428
Author(s):  
Frank Liang ◽  
Azar Rezapour ◽  
Peter Falk ◽  
Eva Angenete ◽  
Ulf Yrlid
Keyword(s):  
Rectal Cancer ◽  
T Cells ◽  
Γδ T Cells ◽  
T Cell Subsets ◽  
Functional Evaluation ◽  
Mait Cells ◽  
Ifn Γ ◽  
Tumor Biopsies

TILs comprise functionally distinct conventional and unconventional T cell subsets and their role in responses to CRC treatments is poorly understood. We explored recovery of viable TILs from cryopreserved tumor biopsies of (chemo)-radiated patients with rectal cancer to establish a platform for retrospective TIL analyses of frozen tumors from pre-selected study cohorts. Frequencies of TIL subsets and their capacity to mount IFN-γ responses in cell suspensions of fresh vs. cryopreserved portions of the same tumor biopsies were determined for platform validation. The percentages and proportions of CD4+ TILs and CD8+ cytotoxic T lymphocytes (CTLs) among total TILs were not affected by cryopreservation. While recovery of unconventional γδ T cells and mucosal-associated invariant T cells (MAIT cells) was stable after cryopreservation, the regulatory T cells (Tregs) were reduced, but in sufficient yields for quantification. IFN-γ production by in vitro-stimulated CD4+ TILs, CTLs, γδ T cells, and MAIT cells were proportionally similar in fresh and cryopreserved tumor portions, albeit the latter displayed lower levels. Thus, the proposed platform intended for TIL analyses on cryopreserved tumor biobank biopsies holds promises for studies linking the quantity and quality of TIL subsets with specific clinical outcome after CRC treatment.

scholarly journals Intracellular cytokine repertoire in different T cell subsets from patients with sarcoidosis

Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 487-493
Author(s):  
M Möllers ◽  
S P Aries ◽  
D Drömann ◽  
B Mascher ◽  
J Braun ◽  
...  
Keyword(s):  
T Cells ◽  
Chronic Disease ◽  
Peripheral Blood ◽  
Pulmonary Sarcoidosis ◽  
T Cell Subsets ◽  
Course Of Disease ◽  
Tnf Α ◽  
Intracellular Expression ◽  
Necrosis Factor ◽  
Memory Lymphocytes

BACKGROUNDPulmonary sarcoidosis is characterised by a mononuclear alveolitis with a predominance of CD4+ T cells and macrophages. We determined the intracellular expression of interferon (IFN)γ, interleukin (IL)-2, tumour necrosis factor (TNF)α, IL-4, IL-5 and IL-10 in CD4+ and CD8+, naive and memory lymphocytes from blood and bronchoalveolar lavage (BAL) fluid using three colour flow cytometry.METHODSEighteen untreated patients with pulmonary sarcoidosis were evaluated and stratified according to whether they had acute or chronic disease.RESULTSSignificantly more T cells expressed Th1 than Th2 type cytokines in both BAL fluid and peripheral blood samples, regardless of clinical presentation. Significantly greater proportions of T cells secreted Th1 type cytokines in BAL fluid than in peripheral blood. Th1 type cytokines were more frequently expressed by peripheral and alveolar T cells in acute disease than in chronic disease. There were no significant differences between CD4+ and CD8+ T cells. Concerning naive and memory lymphocytes, significantly higher CD45RO:CD45RA ratios were found in BAL fluid than in blood, and increased expression of Th2 type cytokines was found in peripheral compared with alveolar memory T cells.CONCLUSIONSOur data support the immunopathogenetic concept of Th1/Th2 imbalance and compartmentalisation in pulmonary sarcoidosis and suggest that the cytokine patterns change during the course of disease. Expression of Th2 type cytokines in memory lymphocytes is decreased in the alveolar compartment compared with peripheral blood.

scholarly journals 678 Addition of a single bacteria facilitates anti-tumor immunity and long-term survival in colorectal cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A717-A717
Author(s):  
Abigail Overacre-Delgoffe ◽  
Anthony Cillo ◽  
Hannah Bumgarner ◽  
Ansen Burr ◽  
Justin Tometich ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
T Cells ◽  
Tumor Immunity ◽  
Tumor Burden ◽  
Intestinal Microbiome ◽  
Tumor Control ◽  
Mesenteric Lymph Nodes ◽  
Term Survival ◽  
16S Sequencing ◽  
Tumor Bearing

BackgroundColorectal cancer remains one of the most common and deadliest cancers worldwide and effective therapies are lacking. While immunotherapy has revolutionized treatment for many cancers, the overwhelming majority of colorectal cancer patients are non-responsive and the 5-year survival rate for advanced disease is <20%. Immunotherapeutic response has been associated with select members of the microbiome in melanoma; however, the potential benefit in colorectal cancer and the underlying mechanisms remain unclear. We sought to determine how specific members of the intestinal microbiome affect anti-tumor immunity in colorectal cancer (CRC) in hopes of discovering novel treatments and revealing potential hurdles to current therapeutic response in CRC patients.MethodsWe utilized a carcinogen-induced mouse model of CRC and colonized half of the tumor-bearing mice with Helicobacter hepaticus (Hhep) 7 weeks post AOM. Tumor number was assessed 12 weeks post AOM. We isolated lymphocytes from the lamina propria, colonic epithelium, mesenteric lymph nodes, and tumor(s) to track the spatial and transcriptional Hhep-specific and endogenous immune responses during tumor progression through 5’ single cell RNAseq, flow cytometry, and immunofluorescence. In addition, we utilized 16S sequencing and FISH to track Hhep colonization, location within the colon, and its impact on the surrounding microbiome.ResultsWe have found that rational modification of the microbiome of colon tumor-bearing mice through addition of a single bacteria, Hhep, led to tumor control or clearance and a significant survival advantage. Colonization led to the expansion of the lymphatic network and development of numerous peri- or intra-tumoral tertiary lymphoid structures (TLS) composed of Hhep-specific CD4 T follicular helper cells (TFH) as well as the bacteria itself. This led to an overall ‘heating’ of the tumor, wherein we saw an increase of CD4 T cell infiltration to the tumor core as well as an increase in CD103+ type 1 DC (cDC1) recruitment through increased chemokines such as CCL5 and XCL1. Hhep-specific TFH were both necessary and sufficient to drive TLS formation, increased immune invasion, and anti-tumor immunity.ConclusionsWe have shown that addition of a single bacteria, Hhep, leads to a reduction in CRC tumor burden or clearance through lymphatic expansion, TLS formation, and remodeling of the tumor microenvironment, and that Hhep-specific T cells are required for tumor control. These studies suggest that rational modification of the microbiome and microbiome-specific T cells can positively impact anti-tumor immunity and may represent a unique immunotherapeutic target to turn resistant tumors into responsive tumors.

scholarly journals Traditional Thai Massage Promoted Immunity in the Elderly via Attenuation of Senescent CD4+ T Cell Subsets: A Randomized Crossover Study

2021 ◽  
Vol 18 (6) ◽  
pp. 3210
Author(s):  
Kanda Sornkayasit ◽  
Amonrat Jumnainsong ◽  
Wisitsak Phoksawat ◽  
Wichai Eungpinichpong ◽  
Chanvit Leelayuwat
Keyword(s):  
T Cells ◽  
T Cell ◽  
Crossover Study ◽  
Intracellular Cytokine Staining ◽  
The Elderly ◽  
Complementary Therapy ◽  
T Cell Subsets ◽  
Cd4 T Cell ◽  
T Subsets ◽  
Randomized Crossover Study

The beneficial physiological effects of traditional Thai massage (TTM) have been previously documented. However, its effect on immune status, particularly in the elderly, has not been explored. This study aimed to investigate the effects of multiple rounds of TTM on senescent CD4+ T cell subsets in the elderly. The study recruited 12 volunteers (61–75 years), with senescent CD4+ T cell subsets, who received six weekly 1-h TTM sessions or rest, using a randomized controlled crossover study with a 30-day washout period. Flow cytometry analysis of surface markers and intracellular cytokine staining was performed. TTM could attenuate the senescent CD4+ T cell subsets, especially in CD4+28null NKG2D+ T cells (n = 12; p < 0.001). The participants were allocated into two groups (low < 2.75% or high ≥ 2.75%) depending on the number of CD4+28null NKG2D+ T cells. After receiving TTM over 6 sessions, the cell population of the high group had significantly decreased (p < 0.001), but the low group had no significant changes. In conclusion, multiple rounds of TTM may promote immunity through the attenuation of aberrant CD4+ T subsets. TTM may be provided as a complementary therapy to improve the immune system in elderly populations.

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