Abstract TP277: CD4 T Cells Increase Tyrosine Hydroxylase Expression With Aging and Stroke in Mice

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Songmi Lee ◽  
Jacob Hudobenko ◽  
Bhanu Priya Ganesh ◽  
Louise McCullough ◽  
Anjali Chauhan
Keyword(s):  
T Cells ◽  
Tyrosine Hydroxylase ◽  
T Lymphocytes ◽  
Ex Vivo ◽  
Ischemic Injury ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Memory Phenotype ◽  
Old Mice ◽  
The Brain

Introduction: Activated T lymphocytes are present in the brain and play a detrimental role in aging and potentiate inflammation after ischemic injury. Previous studies have shown that T lymphocytes (T cells) synthesize and secrete catecholamines that modulate their activation. Tyrosine hydroxylase (TH), is a rate-limiting enzyme in catecholamine synthesis. Little is known about the role and contribution of TH synthesis specifically in T lymphocytes in aging and ischemic stroke injury. We hypothesized that aging will lead to increase TH + T cells in the brain that will have an activated phenotype and contribute to the progression of ischemic injury. Methods: Young (8-12 weeks) and old (22-24 months) C57BL/6 male mice were used. Spleen, bone marrow and brain were harvested and flow cytometry was used to immunophenotype the TH + T cells. Expression of TH on sorted CD4 + and CD8 + T cells was assessed by a real-time polymerase chain reaction. Splenic lymphocytes were stimulated with PMA/ionomycin and different T cell subsets were analyzed. The CD4 + T cells were purified from young and old mouse spleens and ex vivo stimulated to measure cytokine production. Finally, young and old mice underwent 60 minutes of middle cerebral artery occlusion (MCAo) and were euthanized 4 days later to determine the role of TH + T lymphocytes in stroke injury. Results: The percentage and MFI of TH was increased on CD4 + T cells with aging however, no change in TH percentage or MFI on CD8 + T cells was observed. TH RNA was increased in CD4 + T cells derived from old animals. The TH + CD4 + T cells were activated and had an effector memory phenotype in aging. On acute stimulation, old TH + CD4 + T cells increased the production of INF-γ, IL-4, and Il-17. After MCAo the percentage TH + CD4 + T cells increased in both young and old mice in the brain. The MFI IL-4/INF-γ ratio was higher in the young MCAo versus old MCAo reflecting a Th2 related response. Conclusion: TH + CD4 + T cells increase with age. These cells have an activated and effector memory phenotype and secrete inflammatory cytokines on acute stimulation. After MCAo, TH + CD4 + T cells demonstrated Th2 related protective responses in only in young mice.

Ex Vivo Fludarabine Selectively Depletes Human Naive T-Cell Subsets: A Step Toward Modifying Donor Lymphocyte Infusion.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1071-1071
Author(s):  
Melody M. Smith ◽  
Cynthia R. Giver ◽  
Edmund K. Waller ◽  
Christopher R. Flowers
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Memory T Cells ◽  
Ex Vivo ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Naïve T Cell ◽  
Naive T Cell

Abstract Ex vivo modification of donor lymphocytes with purine analogs (mDL) may help to minimize graft versus host disease (GvHD) while providing beneficial graft versus leukemia (GvL) effects. In a murine model system, we have shown that allogeneic donor splenocytes, treated with fludarabine ex vivo have significantly reduced GvHD activity when transferred to irradiated recipient mice, and retain anti-viral and GvL activities (Giver, 2003). This effect appears to be mediated by relative depletion of donor CD4 CD44low, “naive” T-cells. As a first step toward developing mDL for use in patients, we sought to evaluate the effects of ex vivo fludarabine exposure on human T-cell subsets, and to determine the minimum dose of fludarabine required to achieve this effect. Methods: Peripheral blood mononuclear cell samples from 6 healthy volunteers were evaluated at 0, 24, 48, and 72 hour time points after ex vivo incubation in varying dosages of fludarabine: 2, 5, and 10(n=3) mcg/ml. Fludarabine incubated samples were compared to samples that received no fludarabine (untreated). The total viable cell number was determined and the fractions and absolute numbers of viable CD4 and CD8 naïve and memory T-cells were determined using flow cytometry after incubation with 7-AAD (dead cell stain), CD4, CD8, CD45RA, CD62L, and CCR7 antibodies, and measuring the total viable cells/ml. Results: The numbers of viable CD4 and CD8 T-cells remained relatively stable in control cultures. Without fludarabine, the average viability at 72 hr of naive and memory T-cells were 92% and 77% for CD4 and 86% and 63% for CD 8 (Fig. 1A). Naive CD4 T-cells were more sensitive to fludarabine-induced death than memory CD4 cells. At 72 hr, the average viability of fludarabine-treated naive CD4 T-cells was 33% at 2 mcg/ml (8.2X the reduction observed in untreated cells) and 30% at 5 mcg/ml, while memory CD4 T-cells averaged 47% viability at 2 mcg/ml (2.3X the reduction observed in untreated cells) (Fig. 1B) and 38% at 5 mcg/ml. The average viability of naive CD8 T-cells at 72 hr was 27% at 2 mcg/ml and 20% at 5 mcg/ml, while memory CD8 T-cell viability was 22% at 2 mcg/ml and 17% at 5 mcg/ml. Analyses on central memory, effector memory, and Temra T-cells, and B-cell and dendritic cell subsets are ongoing. The 5 and 10 mcg/ml doses also yielded similar results in 3 initial subjects, suggesting that 2 mcg/ml or a lower dose of fludarabine is sufficient to achieve relative depletion of the naive T-cell subset. Conclusions: Future work will determine the minimal dose of fludarabine to achieve this effect, test the feasibility of using ex vivo nucleoside analog incubation to reduce alloreactivity in samples from patient/donor pairs, and determine the maximum tolerated dose of mDL in a phase 1 clinical trial with patients at high risk for relapse and infectious complications following allogeneic transplantation. Figure Figure

Natalizumab treatment alters the expression of T-cell trafficking marker LFA-1 α-chain (CD11a) in MS patients

2013 ◽  
Vol 20 (7) ◽  
pp. 837-842 ◽  
Author(s):  
Samantha Jilek ◽  
Amandine Mathias ◽  
Mathieu Canales ◽  
Andreas Lysandropoulos ◽  
Giuseppe Pantaleo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chemokine Receptors ◽  
Ex Vivo ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Cell Trafficking ◽  
Natalizumab Treatment ◽  
The Central Nervous System ◽  
Cell Expression

Objective: To determine the long-term effect of natalizumab (NTZ) treatment on the expression of integrins and chemokine receptors involved in the migration of T cells towards the central nervous system (CNS). Methods: We drew the blood of 23 patients just before starting NTZ therapy and every 12 months thereafter, for up to 48 months of treatment. We assessed the ex-vivo expression of phenotype markers (CCR7 and CD45RA), CNS-addressing integrins (CD11a, CD49d and CD29) and chemokine receptors (CXCR3 and CCR6) in CD4+ or CD8+ T-cell subsets by flow cytometry. Results: As compared to the pre-NTZ values, there was a marked increase in central memory (CCR7+/CD45RA-) CD4+ T cells and in effector memory (CCR7-/CD45RA-) CD8+ T cells at 12 and 24 months. In addition to an expected downregulation of both VLA-4 subunits (CD49d/CD29), we also found decreased T-cell expression of CXCR3 at 12 months, and of CD11a (LFA-1 αL subunit) at 12 months, but mostly at 24 months of NTZ treatment. Conclusion: Our data show a nadir of CD11a expression at 2 years of NTZ treatment, at the peak of incidence of progressive multifocal leukoencephalopathy (PML), indirectly suggesting that a lack of these molecules may play a role in the onset of PML in NTZ-treated patients.

scholarly journals Early Homeostatic Expansion of Regulatory T Cells with the Predominant Effector/Memory Phenotype May Stabilize Immune Recovery in the First Month after HSCT

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2501-2501
Author(s):  
Takanori Yoshioka ◽  
Yusuke Meguri ◽  
Takeru Asano ◽  
Taro Masunari ◽  
Kumiko Kagawa ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Acute Phase ◽  
Cd4 T Cells ◽  
Chronic Phase ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Ki 67 ◽  
Memory Phenotype ◽  
Post Transplant

Abstract CD4+Foxp3+ regulatory T cells (Treg) play a central role in establishing immune tolerance after allogeneic hematopoietic stem cell transplantation (HSCT). We previously reported that the long-term severe lymphopenia could result in the collapse of Treg homeostasis leading to the onset of chronic GVHD (Matsuoka et al. JCI 2010). However, Treg homeostasis in the very early phase after HSCT has not been well studied. To address this issue, we here examined the early lymphocytes reconstitution in total 34 patients who received HSCT. Peripheral blood samples were obtained at 2, 4, 8 and 12 weeks after transplant and analyzed the reconstitution of CD4+CD25med-highCD127lowFoxp3+ Treg comparing with CD4+CD25neg-lowCD127highFoxp3- conventional T cell (Tcon) and CD8+ T cells. CD4 T cell subsets are further divided into subpopulations by the expression of CD45RA and CD31. The expressions of Helios, Ki-67, Bcl-2 and C-C chemokine receptor type 4 (CCR4) on these subsets were also examined. These patients were transplanted the grafts from various stem cell sources (7 HLA-matched PBSCT, 12 HLA-matched BMT, 6 HLA-mismatched CBT and 9 HLA-haploidentical PBSCT) and this enables us the opportunity to comparatively evaluate the early lymphocyte reconstitution among the different types of HSCT. After transplant, total lymphocyte counts were significantly lower than the counts before the start of conditioning (median lymphocytes 113/ul at 2 weeks and 223/ul at 4 weeks vs 550/ul before conditioning, P<0.01 and P<0.01, respectively). In the severely lymphopenic condition in the first month after HSCT, all T cell subsets were undergoing aggressive proliferation in this acute phase as compared to proliferation in the chronic phase, however, Treg proliferation was significantly higher than in Tcon at 4 weeks (%Ki-67+ cells; median 56.4%, 23.4%, respectively, P<0.02). %Treg of total CD4 T cells elevated and peaked at 4 weeks post-transplant. At this timepoint, %Treg of CD4 T cells showed the clear inverse correlation with %CD45RA+ of Treg (r2=0.40), suggesting the expansion of Treg in this phase appears to be a result from severe lymphopenia-driven proliferation which involves conversion from naive into memory phenotype. Elevation of %Treg was most evident in the patients who received HLA-haploidentical graft after ATG-containing conditioning (median 8.41% in haplo-HSCT, 5.25% in other groups, P<0.05), again indicating the lymphopenia is critical factor to drive Treg proliferatrion. Expanded Treg showed a predominant Helios+CD45RA-CD31- effector/memory phenotype with the lower level of Bcl-2 expression as compared to CD45RA+ naïve Treg. The elevation of Treg did not sustain and %Treg of CD4 T cells got back to the baseline level by 8 weeks. During the first 3 months after HSCT, CD45RA- Treg exhibited high level of CCR4 and the recovery of this subset was critically delayed in Adult T-cell Leukemia (ATL) patients treated with anti-CCR4 antibody in the peri-transplant period, resulting in the development of acute graft-versus-host diseases. In conclusion, our findings suggest that, not only in the chronic phase but also in the acute phase, the homeostasis of Treg is more susceptible to the post-transplant environment as compared to other lymphocyte subsets. Post-transplant lymphopenia drives aggressive Treg proliferation resulting in the increased percentage of this subset in the very acute phase which may contribute to stabilize the immune recovery. The careful monitoring of Treg from the point of view might provide important information to promote immune tolerance. Disclosures No relevant conflicts of interest to declare.

Targeting Lewis Y-Positive Multiple Myeloma and Acute Myeloid Leukemia with Gene-Modified T Cells Demonstrating Memory Phenotype

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3900-3900
Author(s):  
Stefan Peinert ◽  
David S. Ritchie ◽  
Dirk Hoenemann ◽  
Simon J. Harrison ◽  
Preethi Guru ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Memory Phenotype ◽  
Lewis Y ◽  
Active Proliferation

Abstract AML and MM are sensitive to immune control as evidenced by T cell mediated allogeneic graft versus leukemia/myeloma effect. Adoptive immunotherapy with gene modified T cells has shown clinical activity in some solid tumors and B cell non Hodgkin lymphomas. The carbohydrate antigen Lewis Y (LeY) is a tumor associated antigen expressed on numerous epithelial cancers. Our aim was to generate gene-modified clinical-grade T cells directed against LeY positive hematological malignancies. Moreover, we aimed to produce cells that possessed T cell memory, essential for in vivo T cell persistence and long-term control of tumor cell targets. MM and AML cell lines were found to express differing levels of the LeY antigen ranging from negative (median fluorescence intensity (MFI) equal to mature lymphocytes (lymph) as internal control) to strongly positive (up to10×MFI lymph). Furthermore, 25/46 (54%) and 15/29 (52)% of primary MM and AML bone marrow samples were LeY-positive (≥5×MFI lymph), respectively. Lewis Y expression did not correlate with patient age, gender, clinical risk status, cytogenetic abnormalities, extent of previous chemotherapy, degree of bone marrow infiltrate, disease subtype, cytopenias in peripheral blood (MM and AML), LDH, WBC > or ≤ 30×109/L (AML), beta2 microglobulin, albumin or pretreatment with bortezomib, thalidomide or lenalidomide (MM). We manufactured a novel retroviral vector construct enabling efficient transduction of PBMC-derived T cells with resultant high expression (up to 65%) of a single-chain anti-LeY chimeric T cell receptor comprising T cell activation via CD3zeta and CD28 signaling domains. Under GMP conditions, we achieved >100-fold expansion of T cells using a 12 day culture protocol. Anti-LeY T cells lysed LeY-positive tumor cells in vitro while sparing LeY-negative control tumor cells and LeY expressing neutrophils (moderate LeY expression, >3×MFI lymph). Similar transduction rates were achieved in CD4 and CD8 T cell subsets. Twelve-day culture T cells showed low expression levels of CD45RA and CCR7, moderate levels of the co-stimulatory molecules CD27 and CD28, and active proliferation in response to IL-2 and IL-15, suggesting an effector memory phenotype. On re-exposure to LeY expressing tumor cells, anti-LeY T cells displayed active proliferation and IFN-gamma production. In vivo efficacy was demonstrated in three independent experiments of a MM xenograft mouse model showing improved disease free survival of mice receiving anti LeY T cells compared to control mice treated with untransduced T cells. Transplantation of syngeneic murine anti LeY T cells into sublethally irradiated Balb/C mice subsequently monitored for up to two years was found to be safe without generation of lymphoproliferative disorders arising from the anti LeY T cells and no impact on OS compared to irradiated control mice not receiving adoptive T cell transfer. Consequently, we have developed a first in human phase I trial of autologous anti LeY T cells for patients with LeY-positive MM or AML. LeY is a promising and immunologically relevant target for T cell immunotherapy and our product is likely to lead to persistence of anti-LeY T cells in patients, an outcome which will be specifically addressed in our upcoming study.

Ex vivo characterization of human CD8+ T subsets with distinct replicative history and partial effector functions

Blood ◽  
2003 ◽  
Vol 102 (5) ◽  
pp. 1779-1787 ◽  
Author(s):  
Nathalie Rufer ◽  
Alfred Zippelius ◽  
Pascal Batard ◽  
Mikaël J. Pittet ◽  
Isabel Kurth ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Effector Memory ◽  
Effector Functions ◽  
Functional Features ◽  
Naive T Lymphocytes

Abstract After antigenic challenge, naive T lymphocytes enter a program of proliferation and differentiation during the course of which they acquire effector functions and may ultimately become memory cells. In humans, the pathways of effector and memory T-cell differentiation remain poorly defined. Here we describe the properties of 2 CD8+ T-lymphocyte subsets, RA+CCR7–27+28+ and RA+CCR7–27+28–, in human peripheral blood. These cells display phenotypic and functional features that are intermediate between naive and effector T cells. Like naive T lymphocytes, both subsets show relatively long telomeres. However, unlike the naive population, these T cells exhibit reduced levels of T-cell receptor excision circles (TRECs), indicating they have undergone additional rounds of in vivo cell division. Furthermore, we show that they also share effector-type properties. At equivalent in vivo replicative history, the 2 subsets express high levels of Fas/CD95 and CD11a, as well as increasing levels of effector mediators such as granzyme B, perforin, interferon γ, and tumor necrosis factor α. Both display partial ex vivo cytolytic activity and can be found among cytomegalovirus-specific cytolytic T cells. Taken together, our data point to the presence of T cells with intermediate effector-like functions and suggest that these subsets consist of T lymphocytes that are evolving toward a more differentiated effector or effector-memory stage.

scholarly journals Differentiation into an Effector Memory Phenotype Potentiates HIV-1 Latency Reversal in CD4+ T Cells

2019 ◽  
Vol 93 (24) ◽  
Author(s):  
Deanna A. Kulpa ◽  
Aarthi Talla ◽  
Jessica H. Brehm ◽  
Susan Pereira Ribeiro ◽  
Sally Yuan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Cell Surface Markers ◽  
Cell Cycle Entry ◽  
Latent Hiv ◽  
Hiv 1

ABSTRACT During antiretroviral therapy (ART), human immunodeficiency virus type 1 (HIV-1) persists as a latent reservoir in CD4+ T cell subsets in central memory (TCM), transitional memory (TTM), and effector memory (TEM) CD4+ T cells. We have identified differences in mechanisms underlying latency and responses to latency-reversing agents (LRAs) in ex vivo CD4+ memory T cells from virally suppressed HIV-infected individuals and in an in vitro primary cell model of HIV-1 latency. Our ex vivo and in vitro results demonstrate the association of transcriptional pathways of T cell differentiation, acquisition of effector function, and cell cycle entry in response to LRAs. Analyses of memory cell subsets showed that effector memory pathways and cell surface markers of activation and proliferation in the TEM subset are predictive of higher frequencies of cells carrying an inducible reservoir. Transcriptional profiling also demonstrated that the epigenetic machinery (known to control latency and reactivation) in the TEM subset is associated with frequencies of cells with HIV-integrated DNA and inducible HIV multispliced RNA. TCM cells were triggered to differentiate into TEM cells when they were exposed to LRAs, and this increase of TEM subset frequencies upon LRA stimulation was positively associated with higher numbers of p24+ cells. Together, these data highlight differences in underlying biological latency control in different memory CD4+ T cell subsets which harbor latent HIV in vivo and support a role for differentiation into a TEM phenotype in facilitating latency reversal. IMPORTANCE By performing phenotypic analysis of latency reversal in CD4+ T cells from virally suppressed individuals, we identify the TEM subset as the largest contributor to the inducible HIV reservoir. Differential responses of memory CD4+ T cell subsets to latency-reversing agents (LRAs) demonstrate that HIV gene expression is associated with heightened expression of transcriptional pathways associated with differentiation, acquisition of effector function, and cell cycle entry. In vitro modeling of the latent HIV reservoir in memory CD4+ T cell subsets identify LRAs that reverse latency with ranges of efficiency and specificity. We found that therapeutic induction of latency reversal is associated with upregulation of identical sets of TEM-associated genes and cell surface markers shown to be associated with latency reversal in our ex vivo and in vitro models. Together, these data support the idea that the effector memory phenotype supports HIV latency reversal in CD4+ T cells.

scholarly journals Distinctive CD26 Expression on CD4 T-Cell Subsets

Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1446
Author(s):  
Oscar J. Cordero ◽  
Carlos Rafael-Vidal ◽  
Rubén Varela-Calviño ◽  
Cristina Calviño-Sampedro ◽  
Beatriz Malvar-Fernández ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Surface ◽  
Cd4 T Cells ◽  
Ex Vivo ◽  
T Cell Subsets ◽  
Effector Memory ◽  
T Helper ◽  
Cd26 Expression

Immune system CD4 T-cells with high cell-surface CD26 expression show anti-tumoral properties. When engineered with a chimeric antigen receptor (CAR), they incite strong responses against solid cancers. This subset was originally associated to human CD4 T helper cells bearing the CD45R0 effector/memory phenotype and later to Th17 cells. CD26 is also found in soluble form (sCD26) in several biological fluids, and its serum levels correlate with specific T cell subsets. However, the relationship between glycoprotein sCD26 and its dipeptidyl peptidase 4 (DPP4) enzymatic activity, and cell-surface CD26 expression is not well understood. We have studied ex vivo cell-surface CD26 and in vitro surface and intracellular CD26 expression and secretome’s sCD26 in cultured CD4 T cells under different polarization conditions. We show that most human CD26negative CD4 T cells in circulating lymphocytes are central memory (TCM) cells while CD26high expression is present in effector Th1, Th2, Th17, and TEM (effector memory) cells. However, there are significant percentages of Th1, Th2, Th17, and Th22 CD26 negative cells. This information may help to refine the research on CAR-Ts. The cell surface CD45R0 and CD26 levels in the different T helper subsets after in vitro polarization resemble those found ex vivo. In the secretomes of these cultures there was a significant amount of sCD26. However, in all polarizations, including Th1, the levels of sCD26 were lower (although not significantly) compared to the Th0 condition (activation without polarization). These differences could have an impact on the various physiological functions proposed for sCD26/DPP4.

scholarly journals Ex Vivo Kinetics of Early and Long-Term Multifunctional Human Leukocyte Antigen E-Specific CD8+ Cells in Volunteers Immunized with the Ty21a Typhoid Vaccine

2010 ◽  
Vol 17 (9) ◽  
pp. 1305-1314 ◽  
Author(s):  
Rosângela Salerno-Goncalves ◽  
Rezwanul Wahid ◽  
Marcelo B. Sztein
Keyword(s):  
T Cells ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Typhoid Vaccine ◽  
Tnf Α ◽  
Ifn Γ ◽  
Kinetics Of

ABSTRACT T cells are likely to play an important role in the host defense against Salmonella enterica serovar Typhi, the causative agent of typhoid fever. We have shown that HLA-E can function as a restriction element for S. Typhi-specific CD8+ T cells. Because of the potential importance of HLA-E-restricted CD8+ responses in resistance to Salmonella infection, we characterized these responses and investigated their kinetics of appearance and persistence in volunteers immunized orally with the licensed attenuated Ty21a strain typhoid vaccine. Cells were obtained from volunteers before and at days 2, 4, 7, 10, 14, 28, 42, 56, 120, 180, 360, and 720 after immunization. An ex vivo multicolor staining panel including antibodies to CD107a and -b, interleukin-2, gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) was used to functionally assess memory T-cell subsets by flow cytometry. Increases in cytokine-secreting CD8+ cells were observed in the T effector/memory (TEM) and CD45RA+ TEM (TEMRA) subsets as early as 4 days after immunization and persisted, particularly in the TEMRA subset, up to 2 years after immunization. The majority of HLA-E-restricted CD8+ cells 28 to 56 days after immunization coexpressed CD107, IFN-γ, and TNF-α, showing characteristic features of multifunctional T cells. In summary, the multifunctionality and longevity of the HLA-E-restricted CD8 responses observed in this study highlight their significance in adaptive immunity to S. Typhi. Finally, this is the first demonstration, in either animals or humans, of the presence of long-term multifunctional HLA-E-restricted CD8+ cells after immunization.

Adoptive Immunotherapy with Memory T Cells.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. sci-25-sci-25 ◽  
Author(s):  
Helen E. Heslop
Keyword(s):  
T Cells ◽  
T Cell ◽  
Memory T Cells ◽  
Ex Vivo ◽  
Central Memory ◽  
Effector Memory ◽  
Memory Phenotype ◽  
Effector Memory T Cells ◽  
Effector Memory Cells

Clinical adoptive cellular immunotherapy of malignancy and viral infection should transfer T cells that expand in vivo on exposure to antigen and can enter the memory compartment to persist long-term. A number of factors, including cellular phenotype, influence the behavior of the infused line. Primate studies have shown that antigen-specific CD8+ T cell clones only persisted long-term in vivo if they were derived from central memory T cells, but not from effector memory T cells, reacquiring phenotypic and functional properties of memory T cells.1 Other studies have suggested that adoptive transfer of ex vivo-expanded effector memory T cells will have poor survival and clinical efficacy, reporting instead that less differentiated T cells with longer telomeres exhibit longer persistence. These data imply that prolonged ex vivo expansion, required, for example, for T cell cloning, adversely affects subsequent in vivo expansion and survival. However, our trials administering ex vivo-expanded, polyclonal EBV-specific T cell lines demonstrated that expanded effector memory T cells, infused into a lymphodepleted host, can expand massively in vivo, enter the memory compartment, and persist for up to seven years after infusion. Furthermore, in a study infusing trivirus-specific CTLs with effector memory phenotype, we saw expansion of CTLs specific for the latent viruses CMV and EBV. By contrast, adenoviral-specific CTL persisted only in patients who were acutely infected with the agent2 We recently compared non-specifically activated T cells (ATC) with EBV-specific CTLs derived from the same initial peripheral blood collection and expressing distinguishable chimeric GD2-specific chimeric antigen receptors (CARATC and CAR-CTL). In this study, ATCs were cultured for 14 to 21 days. Between 0.9% and 6.1% retained a central memory (CCR7+, CD62L+) phenotype, up to 30% had an effector memory phenotype (CCR7−, CD62L+), and the remainder had a terminally/fully differentiated effector phenotype. By contrast, EBV-CTL were cultured for 30 to 44 days and expressed no CCR7, but up to 50% were CD62L+, and contained cells that were terminally/fully differentiated effectors and effector memory cells. These EBV-CTLs also all had a CD45RO memory phenotype, while about 13% to 60% of ATCs expressed CD45RA, a marker of naïve T cells. Despite these differences in memory subsets, it was the CAR-CTLs that had the clearly greater persistence and could be shown to retain functionality, while CAR-ATC rapidly disappeared from the circulation and could not be recovered. Hence, factors other than phenotype, such as antigenic stimulation and costimulation almost certainly influence cell fate after infusion, and determine whether or not effector memory cells can re-access the central memory pool. Ultimately, strategies that combine selection of optimal phenotype with the provision of antigen stimulation and co-stimulation and a cytokine milieu that favors homeostatic expansion will likely lead to the most effective outcomes following adoptive T cell transfer.

scholarly journals Role of T cells during the cerebral infection with Trypanosoma brucei

2021 ◽  
Vol 15 (9) ◽  
pp. e0009764
Author(s):  
Gabriela C. Olivera ◽  
Leonie Vetter ◽  
Chiara Tesoriero ◽  
Federico Del Gallo ◽  
Gustav Hedberg ◽  
...  
Keyword(s):  
T Cells ◽  
Trypanosoma Brucei ◽  
Late Stage ◽  
Early Stage ◽  
Brain Parenchyma ◽  
Effector Memory ◽  
Dependent Manner ◽  
Memory Phenotype ◽  
The Brain

The infection by Trypanosoma brucei brucei (T.b.b.), a protozoan parasite, is characterized by an early-systemic stage followed by a late stage in which parasites invade the brain parenchyma in a T cell-dependent manner. Here we found that early after infection effector-memory T cells were predominant among brain T cells, whereas, during the encephalitic stage T cells acquired a tissue resident memory phenotype (TRM) and expressed PD1. Both CD4 and CD8 T cells were independently redundant for the penetration of T.b.b. and other leukocytes into the brain parenchyma. The role of lymphoid cells during the T.b.b. infection was studied by comparing T- and B-cell deficient rag1-/- and WT mice. Early after infection, parasites located in circumventricular organs, brain structures with increased vascular permeability, particularly in the median eminence (ME), paced closed to the sleep-wake regulatory arcuate nucleus of the hypothalamus (Arc). Whereas parasite levels in the ME were higher in rag1-/- than in WT mice, leukocytes were instead reduced. Rag1-/- infected mice showed increased levels of meca32 mRNA coding for a blood /hypothalamus endothelial molecule absent in the blood-brain-barrier (BBB). Both immune and metabolic transcripts were elevated in the ME/Arc of WT and rag1-/- mice early after infection, except for ifng mRNA, which levels were only increased in WT mice. Finally, using a non-invasive sleep-wake cycle assessment method we proposed a putative role of lymphocytes in mediating sleep alterations during the infection with T.b.b. Thus, the majority of T cells in the brain during the early stage of T.b.b. infection expressed an effector-memory phenotype while TRM cells developed in the late stage of infection. T cells and parasites invade the ME/Arc altering the metabolic and inflammatory responses during the early stage of infection and modulating sleep disturbances.

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