scholarly journals Ligand Binding Sites of Inducible Costimulator and High Avidity Mutants with Improved Function

2002 ◽  
Vol 195 (8) ◽  
pp. 1033-1041 ◽  
Author(s):  
Shengdian Wang ◽  
Gefeng Zhu ◽  
Koji Tamada ◽  
Lieping Chen ◽  
Jürgen Bajorath
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Ligand Binding ◽  
Binding Sites ◽  
T Cell Response ◽  
Surface Patch ◽  
High Avidity ◽  
Wild Type ◽  
Ligand Interaction ◽  
Inducible Costimulator

Interaction between inducible costimulator (ICOS) and its ligand is implicated in the induction of cell-mediated and humoral immune responses. However, the molecular details of this interaction are unknown. We report here a mutagenesis analysis of residues in ICOS that are critical for ligand binding. A three-dimensional model of the extracellular immunoglobulin-like domain of ICOS was used to map the residues conserved within the CD28 family. This analysis identified a surface patch containing the characteristic “PPP” sequence and is conserved in human and mouse ICOS. Mutations in this region of human ICOS reduce or abolish ligand binding. Our results suggest that the ligand binding site in ICOS maps to a region overlapping yet distinct from the CD80/CD86 binding sites in CD28 and cytotoxic T lymphocyte antigen (CTLA)-4. Thus, the analysis suggests that differences in ligand binding specificity between these related costimulatory molecules have evolved by utilization of overlapping regions with different patterns of conserved and nonconserved residues. Two site-specific mutants generated in the course of our studies bound ICOS ligand with higher avidity than wild-type ICOS. An S76E mutant protein of ICOS blocked T cell costimulatory function of ICOS ligand and inhibited T cell response to allogeneic antigens superior to wild-type ICOS. Our studies thus identified critical residues involving in ICOS receptor–ligand interaction and provide new modulators for immune responses.

Age-related heterogeneity in Neutralising antibody responses to SARS-CoV-2 following BNT162b2 vaccination

2021 ◽  
Author(s):  
Dami Collier ◽  
Isabella Ferreira ◽  
Rawlings Datir ◽  
Bo Meng ◽  
Laura Bergamaschi ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Somatic Hypermutation ◽  
Geometric Mean ◽  
T Cell Response ◽  
Antibody Responses ◽  
High Risk Population ◽  
Age Group ◽  
Wild Type ◽  
Dosing Interval

Background Vaccines remain the cornerstone for containing the SARS-CoV-2 pandemic. mRNA vaccines provide protection in clinical trials using a two-dose approach, separated by a three to four week gap. UK policy in 2021 is to extend the dosing interval from three to twelve weeks and other countries are likely to follow suit given the demand for mRNA vaccines and ongoing uncontrolled transmission. There is a paucity of data in the elderly, even though these individuals are the first to receive vaccines due to risk of severe disease. Here we assessed real world immune responses following vaccination with mRNA-based vaccine BNT162b2. Methods: We did a prospective cohort study of 101 individuals presenting for first dose vaccination, with a subset having the second dose. Following the first and second doses of the BNT162b2 vaccine, we measured binding antibody (IgA, IgG and IgG1-4) responses to Spike and Spike RBD, serum neutralising antibody responses to wild type (Wuhan-1 with D614G) and the B.1.1.7 Spike variant using a lentiviral pseudotyping system. We also analysed B cell repertoires and autoantibodies were measured. We measured spike specific IFNgamma; and IL-2 T cell responses and CMV serostatus. We correlated age with immune responses and compared responses after the first and second doses. Results Median age was 81 years amongst 101 participants after the first dose of the BNT162b2 vaccine. Geometric mean neutralisation titres in participants over 80 years old after the first dose were lower than in younger individuals [83.4 (95% CI 52.0-133.7) vs 46.6 (95% CI 33.5-64.8) p 0.01]. A lower proportion of participants 80 years and older achieved adequate neutralisation titre of >1:20 for 50% neutralisation as compared to those under 80 (21% vs 51%, p 0.003). Binding IgG responses correlated with neutralisation. Sera from participants in both age groups showed significantly lower neutralisation potency against B.1.1.7 Spike pseudotyped viruses as compared to wild type. The adjusted ORs for inadequate neutralisation in the 80 years and above age group were 3.7 (95% CI 1.2-11.2) and 4.4 (95% CI 1.5-12.6) against wild type and B.1.1.7 pseudotyped viruses. We observed a trend towards lower somatic hypermutation in participants with suboptimal neutralisation, and elderly participants demonstrated clear reduction in class switched somatic hypermutation, driven by the IgA1/2 isotype. SARS-CoV-2 Spike specific T- cell IFNgamma; and IL-2 responses were impaired in the older age group after 1 dose and although IFN𝛾 increased between vaccine doses, IL-2 responses did not significantly increase. Conclusions There was a significantly higher risk of suboptimal neutralising antibody and T cell response following first dose vaccination with BNT162b2 in half of participants above the age of 80, persisting up to 12 weeks. We caution against extending the dosing interval in this high risk population where B.1.1.7 and other variants of concern are circulating.

scholarly journals Immune Restoration Diseases Reflect Diverse Immunopathological Mechanisms

2009 ◽  
Vol 22 (4) ◽  
pp. 651-663 ◽  
Author(s):  
Patricia Price ◽  
David M. Murdoch ◽  
Upasna Agarwal ◽  
Sharon R. Lewin ◽  
Julian H. Elliott ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
De Novo ◽  
Granulomatous Inflammation ◽  
T Cell Response ◽  
Immune Restoration ◽  
Immunological Parameters ◽  
Varicella Zoster

SUMMARY Up to one in four patients infected with human immunodeficiency virus type 1 and given antiretroviral therapy (ART) experiences inflammatory or cellular proliferative disease associated with a preexisting opportunistic infection, which may be subclinical. These immune restoration diseases (IRD) appear to result from the restoration of immunocompetence. IRD associated with intracellular pathogens are characterized by cellular immune responses and/or granulomatous inflammation. Mycobacterial and cryptococcal IRD are attributed to a pathological overproduction of Th1 cytokines. Clinicopathological characteristics of IRD associated with viral infections suggest different pathogenic mechanisms. For example, IRD associated with varicella-zoster virus or JC polyomavirus infection correlate with a CD8 T-cell response in the central nervous system. Exacerbations or de novo presentations of hepatitis associated with hepatitis C virus (HCV) infection following ART may also reflect restoration of pathogen-specific immune responses as titers of HCV-reactive antibodies rise in parallel with liver enzymes and plasma markers of T-cell activation. Correlations between immunological parameters assessed in longitudinal sample sets and clinical presentations are required to illuminate the diverse immunological scenarios described collectively as IRD. Here we present salient clinical features and review progress toward understanding their pathogeneses.

scholarly journals A role for CD9 molecules in T cell activation.

1996 ◽  
Vol 184 (2) ◽  
pp. 753-758 ◽  
Author(s):  
X G Tai ◽  
Y Yashiro ◽  
R Abe ◽  
K Toyooka ◽  
C R Wood ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
Expression Cloning ◽  
Wild Type ◽  
Almost All ◽  
Antigen Presenting ◽  
Deficient Mice

Costimulation mediated by the CD28 molecule plays an important role in optimal activation of T cells. However, CD28-deficient mice can mount effective T cell-dependent immune responses, suggesting the existence of other costimulatory systems. In a search for other costimulatory molecules on T cells, we have developed a monoclonal antibody (mAb) that can costimulate T cells in the absence of antigen-presenting cells (APC). The molecule recognized by this mAb, 9D3, was found to be expressed on almost all mature T cells and to be a protein of approximately 24 kD molecular mass. By expression cloning, this molecule was identified as CD9, 9D3 (anti-CD9) synergized with suboptimal doses of anti-CD3 mAb in inducing proliferation by virgin T cells. Costimulation was induced by independent ligation of CD3 and CD9, suggesting that colocalization of these two molecules is not required for T cell activation. The costimulation by anti-CD9 was as potent as that by anti-CD28. Moreover, anti-CD9 costimulated in a CD28-independent way because anti-CD9 equally costimulated T cells from the CD28-deficient as well as wild-type mice. Thus, these results indicate that CD9 serves as a molecule on T cells that can deliver a potent CD28-independent costimulatory signal.

scholarly journals 596 Combining Bempegaldesleukin (CD122-preferential IL-2 pathway agonist) and NKTR-262 (TLR7/8 agonist) pairs local innate activation with systemic CD8+ T cell expansion to enhance anti-tumor immunity

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A626-A626
Author(s):  
Annah Rolig ◽  
Daniel Rose ◽  
Grace Helen McGee ◽  
Saul Kivimae ◽  
Werner Rubas ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Immune Responses ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Cycle Phase ◽  
Tumor Cell Death ◽  
Specific Immunity

BackgroundTumor cell death caused by radiation therapy (RT) can trigger anti-tumor immune responses in part because dying cells release adjuvant factors that amplify and sustain DC and T cell responses. We previously demonstrated that bempegaldesleukin (BEMPEG:NKTR-214, a first-in-class CD122-preferential IL-2 pathway agonist), significantly enhanced the anti-tumor efficacy of RT through a T cell-dependent mechanism. Because RT can induce either immunogenic or tolerogenic cell death, depending on a multitude of factors (radiation dose, cell cycle phase, and tumor microenvironment), we hypothesized that providing a specific immunogenic adjuvant, like intratumoral NKTR-262, a novel toll-like receptor (TLR) 7/8 agonist, to the tumor site would further improve systemic tumor-specific immunity by promoting synergistic activation of local immunostimulatory innate immune responses. Therefore, we evaluated whether intratumoral NKTR-262, combined with systemic BEMPEG treatment would result in improved tumor-specific immunity and survival compared to BEMPEG combined with RT.MethodsTumor-bearing mice (CT26; EMT6) received BEMPEG (0.8 mg/kg; iv), RT (16 Gy x 1), and/or intratumoral NKTR-262 (0.5 mg/kg). Flow cytometry was used to evaluate CD4+ and CD8+ T cell activation status in the blood and tumor (7 days post-treatment). The contribution of specific immune subsets was determined by depletion of CD4+, CD8+, or NK cells. CD8+ T cell cytolytic activity was determined in vitro with an Incucyte assay. Data are representative of 1–2 independent experiments (n=5–14/group) and statistical significance was determined by 1-way ANOVA (p-value cut-off of 0.05).ResultsBEMPEG/NKTR-262 resulted in significantly improved survival compared to BEMPEG/RT. Both combination therapies were CD8+ T cell dependent. However, response to BEMPEG/NKTR-262 was characterized by a significant expansion of activated CD8+ T cells (GzmA+; Ki-67+; ICOS+; PD-1+) in the blood, which correlated with reduced tumor size (p<0.05). In the tumor, BEMPEG/NKTR-262 induced higher frequencies of GzmA+ CD8+ T cells exhibiting reduced expression of suppressive molecules (PD-1+, TIM-3+), compared to BEMPEG/RT. Additionally, CD8+ T cells isolated from BEMPEG/NKTR-262-treated tumors had greater cytolytic capacity than those from BEMPEG/RT-treated mice.ConclusionsCombining BEMPEG with NKTR-262 lead to a more robust expansion of activated CD8+ T cells compared to the BEMPEG/RT combination. Enhancement of the activated CD8+ T cell response in mice treated with NKTR-262 in combination with BEMPEG suggests that intratumoral TLR stimulation provides superior antigen presentation and costimulatory activity compared to RT. A clinical trial of BEMPEG/NKTR-262 for patients with metastatic solid tumors is in progress (NCT03435640).

scholarly journals Improved Immune Responses against Zika Virus after Sequential Dengue and Zika Virus Infection in Human

2018 ◽  
Author(s):  
Felix G. Delgado ◽  
Karina I. Torres ◽  
Jaime E. Castellanos ◽  
Consuelo Romero-Sánchez ◽  
Etienne Simon-Lorière ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
B Cell ◽  
Zika Virus ◽  
Neutralizing Antibodies ◽  
Denv Infection ◽  
T Cell Response ◽  
Zikv Infection ◽  
Cell Responses ◽  
B Cell Responses

The high level of dengue virus (DENV) seroprevalence in areas where Zika virus (ZIKV) is circulating and the cross-reactivity between these two viruses have raised concerns on the risk of increased ZIKV disease severity for patients with a history of previous DENV infection. To determine the role of DENV pre-immunity in ZIKV infection, we analysed the T and B cell responses against ZIKV in donors with or without previous DENV infection. Using PBMCs from donors living in an endemic area in Colombia, we have identified, by interferon (IFN)-&gamma; enzyme-linked immunospot (ELISPOT) assay, most of the immunodominant ZIKV T-cell epitopes in the non-structural proteins NS1, NS3 and NS5. Analyses of the T and B-cell responses in the same donors revealed a stronger T-cell response against peptides conserved between DENV and ZIKV, with a higher level of ZIKV-neutralizing antibodies in DENV-immune donors, in comparison with DENV-na&iuml;ve donors. Strikingly, the potential for antibody mediated enhancement of ZIKV infection was reduced in donors with sequential DENV and ZIKV infection in comparison with donors with DENV infection only. Altogether, these data suggest that individuals with DENV immunity present improved immune responses against ZIKV.

scholarly journals Vaccination against RhoC induces long-lasting immune responses in patients with prostate cancer: results from a phase I/II clinical trial

2020 ◽  
Vol 8 (2) ◽  
pp. e001157
Author(s):  
Juliane Schuhmacher ◽  
Sonja Heidu ◽  
Torben Balchen ◽  
Jennifer Rebecca Richardson ◽  
Camilla Schmeltz ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Phase I ◽  
Cell Response ◽  
Small Gtpase ◽  
T Cell Response ◽  
Effector Memory ◽  
Tolerability Profile

BackgroundPeptide-based vaccination is a rational option for immunotherapy of prostate cancer. In this first-in-man phase I/II study, we assessed the safety, tolerability and immunological impact of a synthetic long peptide vaccine targeting Ras homolog gene family member C (RhoC) in patients with prostate cancer. RhoC is a small GTPase overexpressed in advanced solid cancers, metastases and cancer stem cells.MethodsTwenty-two patients who had previously undergone radical prostatectomy received subcutaneous injections of 0.1 mg of a single RhoC-derived 20mer peptide emulsified in Montanide ISA-51 every 2 weeks for the first six times, then five times every 4 weeks for a total treatment time of 30 weeks. The drug safety and vaccine-specific immune responses were assessed during treatment and thereafter within a 13-month follow-up period. Serum level of prostate-specific antigen was measured up to 26 months postvaccination.ResultsMost patients (18 of 21 evaluable) developed a strong CD4 T cell response against the vaccine, which lasted at least 10 months following the last vaccination. Three promiscuouslypresented HLA-class II epitopes were identified. Vaccine-specific CD4 T cells were polyfunctional and effector memory T cells that stably expressed PD-1 (CD279) and OX-40 (CD134), but not LAG-3 (CD223). One CD8 T cell response was detected in addition. The vaccine was well tolerated and no treatment-related adverse events of grade ≥3 were observed.ConclusionTargeting of RhoC induced a potent and long-lasting T cell immunity in the majority of the patients. The study demonstrates an excellent safety and tolerability profile. Vaccination against RhoC could potentially delay or prevent tumor recurrence and metastasis formation.Trial registration numberNCT03199872.

scholarly journals P02.03 Microwave ablation enhances tumor-specific immune response in patients with hepatocellular carcinoma

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A21.1-A21
Author(s):  
E Staib ◽  
K Leuchte ◽  
M Thelen ◽  
P Gödel ◽  
A Lechner ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Thermal Ablation ◽  
Microwave Ablation ◽  
T Cell Response ◽  
Tumor Control ◽  
Free Survival ◽  
Interleukin 5 ◽  
The Impact

BackgroundThermal ablative therapies, such as microwave ablation (MWA) or radiofrequency ablation (RFA), are standard treatments for HCC. In addition to the local tumor destruction, abscopal effects (a reduction of a tumor mass in areas that were not included in the thermal ablation) could be observed. These systemic effects may be mediated by anti-tumor immune response, which has been described for RFA. MWA is rapidly replacing RFA, but systemic immunostimulatory effects of MWA treatment have been poorly studied.Materials and MethodsPatients receiving MWA for localized HCC were included in this study. Effects of MWA on peripheral blood mononuclear cells (PBMC) of HCC patients treated with MWA were analyzed by multicolor flow cytometry. Tumor-specific immune responses against 7 shared tumor antigens were analyzed using peptide pools in 3-color Fluorospot assays (Interferon-y/Interleukin-5/Interleukin-10). The impact of type, density and localization of tumor-infiltrating lymphocytes was assessed by immunohistochemistry (IHC) of CD3, CD4, CD8, FoxP3, CD38 and CD20 and digital image analyses (Immunoscore) of tumor specimens in an additional cohort of patients who received combined surgical resection and thermal ablation.ResultsWhile comprehensive flow cytometric analyses in sequential samples (day 0, 7 and 90) of a prospective patient cohort (n=23) demonstrated only moderate effects of MWA on circulating immune cell subsets, Fluorospot analyses revealed de novo or enhanced tumor-specific immune responses in 30% of these patients. This anti-tumor immune response was related to tumor control. Interferon-y and Interleukin-5 T cell responses against cancer testis antigens were more frequent in patients with a long-time remission (>12 months) after MWA (7/16) compared to patients suffering from an early relapse (0/13 patients). Presence of tumor-specific T cell response (Interferon-y and/or Interleukin-5) was associated to longer progression-free survival (15.0 vs. 10.0 months). Immunohistochemical analyses of resected tumor samples revealed that a high T cell infiltration in a second tumor lesion at the time of thermal ablation was associated with superior disease-free survival (37.4 vs. 13.1 months).ConclusionsOur data demonstrates remarkable immune-related effects of MWA in HCC patients. This study and provides additional evidence for a combination of thermal ablation and immunotherapy in this challenging disease.Funding‘Koeln Fortune’ and ‘CAP-CMMC’ local research grant (to P.G. and H.A.S.) supported our research.Disclosure InformationE. Staib: None. K. Leuchte: None. M. Thelen: None. P. Gödel: None. A. Lechner: None. P. Zentis: None. M. Garcia-Marquez: None. D. Waldschmidt: None. R.R. Datta: None. R. Wahba: None. C. Wybranski: None. T. Zander: None. A. Quaas: None. U. Drebber: None. D.L. Stippel: None. C. Bruns: None. K. Wennhold: None. M. von Bergwelt-Baildon: None. H.A. Schlösser: None.

scholarly journals Potent HIV-1-Specific CD8 T Cell Responses Induced in Mice after Priming with a Multiepitopic DNA-TMEP and Boosting with the HIV Vaccine MVA-B

Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 424 ◽  
Author(s):  
Beatriz Perdiguero ◽  
Suresh C. Raman ◽  
Cristina Sánchez-Corzo ◽  
Carlos Oscar S. Sorzano ◽  
José Ramón Valverde ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Effective Vaccine ◽  
T Cell Epitopes ◽  
Cell Responses ◽  
Modified Vaccinia Virus Ankara ◽  
Hiv 1

An effective vaccine against Human Immunodeficiency Virus (HIV) still remains the best solution to provide a sustainable control and/or eradication of the virus. We have previously generated the HIV-1 vaccine modified vaccinia virus Ankara (MVA)-B, which exhibited good immunogenicity profile in phase I prophylactic and therapeutic clinical trials, but was unable to prevent viral rebound after antiretroviral (ART) removal. To potentiate the immunogenicity of MVA-B, here we described the design and immune responses elicited in mice by a new T cell multi-epitopic B (TMEP-B) immunogen, vectored by DNA, when administered in homologous or heterologous prime/boost regimens in combination with MVA-B. The TMEP-B protein contained conserved regions from Gag, Pol, and Nef proteins including multiple CD4 and CD8 T cell epitopes functionally associated with HIV control. Heterologous DNA-TMEP/MVA-B regimen induced higher HIV-1-specific CD8 T cell responses with broader epitope recognition and higher polyfunctional profile than the homologous DNA-TMEP/DNA-TMEP or the heterologous DNA-GPN/MVA-B combinations. Moreover, higher HIV-1-specific CD4 and Tfh immune responses were also detected using this regimen. After MVA-B boost, the magnitude of the anti-VACV CD8 T cell response was significantly compromised in DNA-TMEP-primed animals. Our results revealed the immunological potential of DNA-TMEP prime/MVA-B boost regimen and supported the application of these combined vectors in HIV-1 prevention and/or therapy.

Monoclonal antibody and ligand binding sites of the T cell erythrocyte receptor (CD2)

Nature ◽  
1987 ◽  
Vol 329 (6142) ◽  
pp. 842-846 ◽  
Author(s):  
Andrew Peterson ◽  
Brian Seed
Keyword(s):  
Monoclonal Antibody ◽  
T Cell ◽  
Ligand Binding ◽  
Binding Sites ◽  
Ligand Binding Sites

scholarly journals Sustained Specific and Cross-Reactive T Cell Responses to Zika and Dengue Virus NS3 in West Africa

2018 ◽  
Vol 92 (7) ◽  
Author(s):  
Bobby Brooke Herrera ◽  
Wen-Yang Tsai ◽  
Charlotte A. Chang ◽  
Donald J. Hamel ◽  
Wei-Kung Wang ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Dengue Virus ◽  
Zika Virus ◽  
Cell Response ◽  
Vaccine Development ◽  
T Cell Responses ◽  
T Cell Response ◽  
Zikv Infection ◽  
Cell Responses

ABSTRACT Recent studies on the role of T cells in Zika virus (ZIKV) infection have shown that T cell responses to Asian ZIKV infection are important for protection, and that previous dengue virus (DENV) exposure amplifies the protective T cell response to Asian ZIKV. Human T cell responses to African ZIKV infection, however, remain unexplored. Here, we utilized the modified anthrax toxin delivery system to develop a flavivirus enzyme-linked immunosorbent spot (ELISPOT) assay. Using human ZIKV and DENV samples from Senegal, West Africa, our results demonstrate specific and cross-reactive T cell responses to nonstructural protein 3 (NS3). Specifically, we found that T cell responses to NS3 protease are ZIKV and DENV specific, but responses to NS3 helicase are cross-reactive. Sequential sample analyses revealed immune responses sustained many years after infection. These results have important implications for African ZIKV/DENV vaccine development, as well as for potential flavivirus diagnostics based on T cell responses. IMPORTANCE The recent Zika virus (ZIKV) epidemic in Latin America and the associated congenital microcephaly and Guillain-Barré syndrome have raised questions as to why we have not recognized these distinct clinical diseases in Africa. The human immunologic response to ZIKV and related flaviviruses in Africa represents a research gap that may shed light on the mechanisms contributing to protection. The goal of our study was to develop an inexpensive assay to detect and characterize the T cell response to African ZIKV and DENV. Our data show long-term specific and cross-reactive human immune responses against African ZIKV and DENV, suggesting the usefulness of a diagnostic based on the T cell response. Additionally, we show that prior flavivirus exposure influences the magnitude of the T cell response. The identification of immune responses to African ZIKV and DENV is of relevance to vaccine development.

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