scholarly journals Between Innate and Adaptive Immune Responses: NKG2A, NKG2C, and CD8+ T Cell Recognition of HLA-E Restricted Self-Peptides Acquired in the Absence of HLA-Ia

2019 ◽  
Vol 20 (6) ◽  
pp. 1454 ◽  
Author(s):  
Wiebke Pump ◽  
Thomas Kraemer ◽  
Trevor Huyton ◽  
Gia-Gia Hò ◽  
Rainer Blasczyk ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Surface ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Hla Class I ◽  
Cell Receptor ◽  
Class I ◽  
Cell Surface Expression ◽  
Effector Memory ◽  
Surface Stability

On healthy cells the non-classical HLA class Ib molecule HLA-E displays the cognate ligand for the NK cell receptor NKG2A/CD94 when bound to HLA class I signal peptide sequences. In a pathogenic situation when HLA class I is absent, HLA-E is bound to a diverse set of peptides and enables the stimulatory NKG2C/CD94 receptor to bind. The activation of CD8+ T cells by certain p:HLA-E complexes illustrates the dual role of this low polymorphic HLA molecule in innate and adaptive immunity. Recent studies revealed a shift in the HLA-E peptide repertoire in cells with defects in the peptide loading complex machinery. We recently showed that HLA-E presents a highly diverse set of peptides in the absence of HLA class Ia and revealed a non-protective feature against NK cell cytotoxicity mediated by these peptides. In the present study we have evaluated the molecular basis for the impaired NK cell inhibition by these peptides and determined the cell surface stability of individual p:HLA-E complexes and their binding efficiency to soluble NKG2A/CD94 or NKG2C/CD94 receptors. Additionally, we analyzed the recognition of these p:HLA-E epitopes by CD8+ T cells. We show that non-canonical peptides provide stable cell surface expression of HLA-E, and these p:HLA-E complexes still bind to NKG2/CD94 receptors in a peptide-restricted fashion. Furthermore, individual p:HLA-E complexes elicit activation of CD8+ T cells with an effector memory phenotype. These novel HLA-E epitopes provide new implications for therapies targeting cells with abnormal HLA class I expression.

scholarly journals Increase in positive selection of CD8+ T cells in TAP1-mutant mice by human beta 2-microglobulin transgene.

1995 ◽  
Vol 181 (2) ◽  
pp. 787-792 ◽  
Author(s):  
H Martien van Santen ◽  
A Woolsey ◽  
P G Rickardt ◽  
L Van Kaer ◽  
E J Baas ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Surface ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Surface Expression ◽  
Class I ◽  
Cell Surface Expression ◽  
Beta 2 ◽  
Beta 2 Microglobulin ◽  
Selection Of

Mice harboring a deletion of the gene encoding the transporter associated with antigen presentation-1 (TAP1) are impaired in providing major histocompatibility complex (MHC) class I molecules with peptides of cytosolic origin and lack stable MHC class I cell surface expression. They consequently have a strongly reduced number of CD8+ T cells. To examine whether selection of CD8+ T cells is dependent on TAP-dependent peptides, we partially restored MHC class I cell surface expression in TAP1-deficient mice by introduction of human beta 2-microglobulin. We show that selection of functional CD8+ T cells can be augmented in vivo in the absence of TAP1-dependent peptides.

scholarly journals A Novel Strategy for Off-the-Shelf T Cell Therapy Which Evades Allogeneic T Cell and NK Cell Rejection

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1711-1711
Author(s):  
Yong Zhang ◽  
Surbhi Goel ◽  
Aaron Prodeus ◽  
Utsav Jetley ◽  
Yiyang Tan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Hla Class I ◽  
Class Ii ◽  
Class I

Abstract Introduction. Despite the success of autologous chimeric antigen receptor (CAR)-T cells, barriers to a more widespread use of this potentially curative therapy include manufacturing failures and the high cost of individualized production. There is a strong desire for an immediately available cell therapy option; however, development of "off-the-shelf" T cells is challenging. Alloreactive T cells from unrelated donors can cause graft versus host disease (GvHD) for which researchers have successfully used nucleases to reduce expression of the endogenous T cell receptor (TCR) in the allogeneic product. The recognition of allogeneic cells by the host is a complex issue that has not been fully solved to date. Some approaches utilize prolonged immune suppression to avoid immune rejection and increase persistence. Although showing responses in the clinic, this approach carries the risk of infections and the durability of the adoptive T cells is uncertain. Other strategies include deletion of the B2M gene to remove HLA class I molecules and avoid recognition by host CD8 T cells. However, loss of HLA class I sends a "missing-self" signal to natural killer (NK) cells, which readily eliminate B2Mnull T cells. To overcome this, researchers are exploring insertion of the non-polymorphic HLA-E gene, which can provide partial but not full protection from NK cell-mediated lysis. Because activated T cells upregulate HLA class II, rejection by alloreactive CD4 T cells should also be addressed. Methods. Here, we developed an immunologically stealth "off-the-shelf" T cell strategy by leveraging our CRISPR/Cas9 platform and proprietary sequential editing process. To solve the issue of rejection by alloreactive CD4 and CD8 T cells, we knocked out (KO) select HLA class I and class II expression with a sequential editing process. Additionally, we utilize potent TCR-α and -β constant chain (TRAC, TRBC) gRNAs that achieve >99% KO of the endogenous TCR, addressing the risk of GvHD. An AAV-mediated insertion of a CAR or TCR into the TRAC locus is used in parallel with the TRAC KO step to redirect the T cells to tumor targets of interest. Alloreactivity by CD4 and CD8 T cells, NK killing, GvHD induction and T cell function was assessed in vitro and/or in vivo. Results. By knocking out select HLA class I and class II proteins, we were able to avoid host CD4- and CD8-T cell-mediated recognition. Edited T cells were protected from host NK cells, both in vitro and in an in vivo model engrafted with functional human NK cells. TRAC edited donor T cells did not induce GvHD in an immune compromised mouse model over the 90-day evaluation period. Using our proprietary T cell engineering process, we successfully generated allogeneic T cells with sequential KOs and insertion of a tumor-specific TCR or CAR with high yield. Importantly, these allogeneic T cells had comparable functional activity to their autologous T cell counterparts in in vitro assays (tumor cell killing and cytokine release) as well as in vivo tumor models. With a relatively small bank of donors, we can provide an "off-the-shelf" CAR or TCR-T cell solution for a large proportion of the population. Conclusions. We have successfully developed a differentiated "off-the-shelf" approach, which is expected to be safe and cost-effective. It is designed to provide long-term persistence without the need for an immune suppressive regimen. This promising strategy is being applied to our T cell immuno-oncology and autoimmune research candidates. Disclosures Zhang: Intellia Therapeutics: Current Employment. Goel: Intellia Therapeutics: Current Employment. Prodeus: Intellia Therapeutics: Current Employment. Jetley: Intellia Therapeutics: Current Employment. Tan: Intellia Therapeutics: Current Employment. Averill: Intellia Therapeutics: Current Employment. Ranade: Intellia Therapeutics: Current Employment. Balwani: Intellia Therapeutics: Current Employment. Dutta: Intellia Therapeutics: Current Employment. Sharma: Intellia Therapeutics: Current Employment. Venkatesan: Intellia Therapeutics: Current Employment. Liu: Intellia Therapeutics: Current Employment. Roy: Intellia Therapeutics: Current Employment. O′Connell: Intellia Therapeutics: Current Employment. Arredouani: Intellia Therapeutics: Current Employment. Keenan: Intellia Therapeutics: Current Employment. Lescarbeau: Intellia Therapeutics: Current Employment. Schultes: Intellia Therapeutics: Current Employment.

Control Of Cytomegalovirus Reactivation Post Stem Cell Transplantation Is Mediated By Simultaneous Reconstitution Of CD4+ and CD8+ CMV-Specific T Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4530-4530
Author(s):  
Mohammad Raeiszadeh ◽  
Annette Pachnio ◽  
Charles Craddock ◽  
Paul Moss ◽  
Frederick Chen
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Hla Class I ◽  
Viral Reactivation ◽  
Class I ◽  
Effector Memory ◽  
Cell Immunity ◽  
Cmv Reactivation

Haematopoietic stem cell transplant (HSCT) patients commonly suffer from Cytomegalovirus(CMV) reactivation due to the eradication and delayed reconstitution of CMV-specific T cell immunity resulting from T cell depletion and conditioning chemotherapy. Our knowledge of T cell immunity and in particular of antigen specific CD8+ T cell responses has advanced rapidly following the introduction of HLA- class I tetramers which enables the direct enumeration and characterisation of CMV-specific CD8+ T cells. In order to study the broader CMV specific T cells reconstitution post HSCT, we used a novel HLA-class II tetramer to monitor the reconstitution of CD4+ T cells specific to a CMV-derived peptide restricted to HLA-DRB1*0701, in parallel with different HLA class I tetramers identifying CMV specific CD8+ T cells. We analysed longitudinally the immune reconstitution of a cohort of thirteen HLA-DRB1*0701 –matched HSCT patients treated for haematological malignancies and who were at high risk of CMV reactivation where both donors and recipients were CMV seropositive. Twelve received reduced intensity conditioning and T-cell depletion with in vivo Alemtuzumab, and one had non-T cell depleted myeloablative conditioning. Twelve out of 13 longitudinally studied HSCT patients experienced CMV reactivation which included multiple episodes of viremia in 8 out of 12 .The viremia resolved in less than a month of onset in 8 patients where rapid expansion of CMV specific CD4+ and CD8+ T cells was observed in response to onset of viral reactivation. In four patients, late reconstitution of CMV-specific CD4 and CD8 T cells was observed between three and six months post HSCT; these patients suffered from prolonged and multiple episodes of CMV reactivation. In reconstituting patients, there was a considerable increase in the number of CMV-specific CD4+ and CD8+ T cells, from undetectable levels before viral reactivation up to 50x10^3 cells/ml and 370x10^3 cells/ml, respectively. CMV-specific CD4+ and CD8+ T cells expanded in parallel and statistically significant correlation between these cells were observed((p=0.06)). The patient treated with myeloablative conditioning chemotherapy retained considerable numbers of (CMV-specific CD4 cells (28.7x10^3 cells/ml) at four weeks post HSCT and did not have CMV reactivation. Phenotypic analysis showed that CMV specific CD4+ T cells were predominantly effector memory cells (CCR7-CD45RA-) whilst CD8+ T cells were predominantly effector memory/CD45RA+ cells. The majority of CMV specific T cells expressed CD57 molecule and we documented a strong correlation between expansion of specific CD4+ T cells and generation of CD4+CD57+ cells post HSCT. Both CD4 and CD8 T cells specific to CMV appear to be required for the control of viremia. The use of HLA class I and class II tetramers in combination with antibodies against surface markers such as CD57 provides a broader picture of the global T cell immune response to CMV and may inform on clinical outcome and treatment guidance. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Longitudinal Changes in Cd4+, Cd8+ T Cell Phenotype and Activation Marker Expression Following Antiretroviral Therapy Initiation among Patients with Cryptococcal Meningitis

2019 ◽  
Vol 5 (3) ◽  
pp. 63
Author(s):  
Alice Bayiyana ◽  
Samuel Okurut ◽  
Rose Nabatanzi ◽  
Godfrey Zziwa ◽  
David R. Boulware ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Cell Surface ◽  
Cd8 T Cells ◽  
Cryptococcal Meningitis ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Effector Memory ◽  
Memory Subset

Despite improvement in the prognosis of HIV/AIDS (human immunodeficiency virus/acquired immune deficiency syndrome) patients on antiretroviral therapy (ART), cryptococcal meningitis (CM) still causes 10–15% mortality among HIV-infected patients. The immunological impact of ART on the CD4+ and CD8+ T cell repertoire during cryptococcal co-infection is unclear. We determined longitudinal phenotypic changes in T cell subsets among patients with CM after they initiated ART. We hypothesized that ART alters the clonotypic phenotype and structural composition of CD4+ and CD8+ T cells during CM co-infection. For this substudy, peripheral blood mononuclear cells (PBMC) were isolated at four time points from CM patients following ART initiation during the parent study (ClinicalTrials.gov number, NCT01075152). Phenotypic characterization of CD4+ and CD8+ T cells was done using T cell surface marker monoclonal antibodies by flow cytometry. There was variation in the expression of immunophenotypic markers defining central memory (CD27+CD45R0+), effector memory (CD45R0+CD27–), immune activation (CD38+ and Human Leucocyte Antigen DR (HLA-DR+), and exhaustion (Programmed cell death protein one (PD-1) in the CD4+ T cell subset. In comparison to the CD4+ T cell population, the CD8+ central memory subset declined gradually with minimal increase in the effector memory subset. Both CD4+ and CD8+ T cell immune exhaustion and activation markers remained elevated over 12 weeks. The relative surge and decline in the expression of T cell surface markers outlines a variation in the differentiation of CD4+ T cells during ART treatment during CM co-infection.

scholarly journals CD27 Expression Promotes Long-Term Survival of Functional Effector–Memory CD8+Cytotoxic T Lymphocytes in HIV-infected Patients

2004 ◽  
Vol 200 (11) ◽  
pp. 1407-1417 ◽  
Author(s):  
Adrian F. Ochsenbein ◽  
Stanley R. Riddell ◽  
Michele Brown ◽  
Lawrence Corey ◽  
Gabriela M. Baerlocher ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Cd8 T Cells ◽  
Interleukin 2 ◽  
Tumor Necrosis Factor Receptor ◽  
Cell Receptor ◽  
Effector Memory ◽  
Term Survival ◽  
Functional Consequences

Human immunodeficiency virus (HIV)-specific CD8+ T cells persist in high frequencies in HIV-infected patients despite impaired CD4+ T helper response to the virus, but, unlike other differentiated effector cytotoxic T lymphocytes, most continue to express the tumor necrosis factor receptor family member CD27. Because the ligand for CD27 (CD70) is also overexpressed in HIV-infected hosts, we examined the nature of expression and potential functional consequences of CD27 expression on HIV-specific CD8+ T cells. Analysis of CD27+ and CD27− T cells derived from the same HIV-specific clone revealed that retention of CD27 did not interfere with acquisition of effector functions, and that after T cell receptor stimulation, CD27+ cells that concurrently were triggered via CD27 exhibited more resistance to apoptosis, interleukin 2 production, and proliferation than CD27− T cells. After transfer back into an HIV-infected patient, autologous HIV-specific CD27− T cells rapidly disappeared, but CD27+ T cells derived from the same clone persisted at high frequency. Our findings suggest that the CD27–CD70 interaction in HIV infection may provide CD27+ CD8+ T cells with a survival advantage and compensate for limiting or absent CD4+ T help to maintain the CD8 response.

scholarly journals Back signaling of HLA class I molecules and T/ NK cell receptor ligands in epithelial cells reflects the rejection‐specific microenvironment in renal allograft biopsies

2019 ◽  
Vol 19 (10) ◽  
pp. 2692-2704 ◽  
Author(s):  
Johanna Egelkamp ◽  
Evgeny Chichelnitskiy ◽  
Jenny F. Kühne ◽  
Franziska Wandrer ◽  
Kerstin Daemen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Renal Allograft ◽  
Nk Cell ◽  
Hla Class I ◽  
Cell Receptor ◽  
Class I ◽  
Receptor Ligands ◽  
Hla Class I Molecules ◽  
Nk Cell Receptor

scholarly journals Heterogeneous phenotypes of expression of the NKB1 natural killer cell class I receptor among individuals of different human histocompatibility leukocyte antigens types appear genetically regulated, but not linked to major histocompatibililty complex haplotype.

1996 ◽  
Vol 183 (4) ◽  
pp. 1817-1827 ◽  
Author(s):  
J E Gumperz ◽  
N M Valiante ◽  
P Parham ◽  
L L Lanier ◽  
D Tyan
Keyword(s):  
T Cells ◽  
Cell Surface ◽  
Nk Cells ◽  
Natural Killer ◽  
Killer Cell ◽  
Peripheral Blood Lymphocytes ◽  
Class I ◽  
Cell Surface Expression ◽  
Target Cells ◽  
Hla Type

Natural killer (NK) cells that express the NKB1 receptor are inhibited from killing target cells that possess human histocompatibility leukocyte antigen (HLA) B molecules bearing the Bw4 serological epitope. To investigate whether NKB1 expression is affected by HLA type, peripheral blood lymphocytes of 203 HLA-typed donors were examined. Most donors had a single population of NKB1+ cells, but some had two populations expressing different cell surface levels of NKB1, and others had no detectable NKB1+ cells. Among the donors expressing NKB1, both the relative abundance of NKB1+ NK cells and their level of cell surface expression varied substantially. The percentage of NKB1+ NK cells ranged from 0 to >75% (mean 14.7%), and the mean fluorescence of the positive population varied over three orders of magnitude. For each donor, the small percentage of T cells expressing NKB1 (usually <2%), had a pattern of expression mirroring that of the NK cells. NKB1 expression by NK and T cells remained stable over the 2-yr period that five donors were tested. Patterns of NKB1 expression were not associated with Bw4 or Bw6 serotype of the donor or with the presence of any individual HLA-A or -B antigens. Cells expressing NKB1 are often found in donors who do not possess an appropriate class I ligand, and can be absent in those who express Bw4+ HLA-B antigens. Family studies further suggested that the phenotype of NKB1 expression is inherited but not HLA linked. Whereas identical twins show matching patterns of NKB1 expression, HLA-identical siblings can differ in NKB1 expression, and conversely, HLA-disparate siblings can be similar. Thus NKB1 expression phenotypes are tightly regulated and extremely heterogeneous, but not correlated with HLA type.

scholarly journals Transient and persistent effects of IL-15 on lymphocyte homeostasis in nonhuman primates

Blood ◽  
2010 ◽  
Vol 116 (17) ◽  
pp. 3238-3248 ◽  
Author(s):  
Enrico Lugli ◽  
Carolyn K. Goldman ◽  
Liyanage P. Perera ◽  
Jeremy Smedley ◽  
Rhonda Pung ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Nk Cell ◽  
The Body ◽  
Effector Memory ◽  
Memory Cd8 T Cells

Abstract Interleukin-15 (IL-15) is a cytokine with potential therapeutic application in individuals with cancer or immunodeficiency to promote natural killer (NK)– and T-cell activation and proliferation or in vaccination protocols to generate long-lived memory T cells. Here we report that 10-50 μg/kg IL-15 administered intravenously daily for 12 days to rhesus macaques has both short- and long-lasting effects on T-cell homeostasis. Peripheral blood lymphopenia preceded a dramatic expansion of NK cells and memory CD8 T cells in the circulation, particularly a 4-fold expansion of central memory CD8 T cells and a 6-fold expansion of effector memory CD8 T cells. This expansion is a consequence of their activation in multiple tissues. A concomitant inverted CD4/CD8 T-cell ratio was observed throughout the body at day 13, a result of preferential CD8 expansion. Expanded T- and NK-cell populations declined in the blood soon after IL-15 was stopped, suggesting migration to extralymphoid sites. By day 48, homeostasis appears restored throughout the body, with the exception of the maintenance of an inverted CD4/CD8 ratio in lymph nodes. Thus, IL-15 generates a dramatic expansion of short-lived memory CD8 T cells and NK cells in immunocompetent macaques and has long-term effects on the balance of CD4+ and CD8+ T cells.

scholarly journals The impact of HLA class I and EBV latency‐II antigen‐specific CD8 + T cells on the pathogenesis of EBV + Hodgkin lymphoma

2015 ◽  
Vol 183 (2) ◽  
pp. 206-220 ◽  
Author(s):  
K. Jones ◽  
L. Wockner ◽  
R. M. Brennan ◽  
C. Keane ◽  
P. K. Chattopadhyay ◽  
...  
Keyword(s):  
T Cells ◽  
Hodgkin Lymphoma ◽  
Cd8 T Cells ◽  
Hla Class I ◽  
Class I ◽  
The Impact
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