scholarly journals Rational Combination of Peptides Derived from Different Mycobacterium leprae Proteins Improves Sensitivity for Immunodiagnosis of M. leprae Infection

2008 ◽  
Vol 15 (3) ◽  
pp. 522-533 ◽  
Author(s):  
Annemieke Geluk ◽  
Jolien van der Ploeg ◽  
Rose O. B. Teles ◽  
Kees L. M. C. Franken ◽  
Corine Prins ◽  
...  
Keyword(s):  
T Cell ◽  
Early Stage ◽  
T Cell Responses ◽  
Hla Class I ◽  
Mycobacterium Leprae ◽  
Diagnostic Tools ◽  
Cell Responses ◽  
Diagnostic Potential ◽  
Leprosy Patients ◽  
Hla Binding

ABSTRACT The stable incidence of new leprosy cases suggests that transmission of infection is continuing despite the worldwide implementation of multidrug therapy programs. Highly specific tools are required to accurately diagnose asymptomatic and early stage Mycobacterium leprae infections which are the likely sources of transmission and cannot be identified by using the detection of antibodies against phenolic glycolipid I. One of the hurdles hampering T-cell-based diagnostic tests is that M. leprae antigens cross-react at the T-cell level with antigens present in other mycobacteria, like M. tuberculosis or M. bovis bacillus Calmette-Guerin (BCG). Using comparative genomics, we previously identified five candidate proteins highly restricted to M. leprae which showed promising features with respect to application in leprosy diagnostics. However, despite the lack of overall sequence homology, the use of recombinant proteins includes the risk of detecting T-cell responses that are cross-reactive with other antigens. To improve the diagnostic potential of these M. leprae sequences, we used 50 synthetic peptides spanning the sequences of all five proteins for the induction of T-cell responses (gamma interferon) in leprosy patients, healthy household contacts (HHC) of leprosy patients, and healthy controls in Brazil, as well as in tuberculosis patients, BCG vaccinees, and healthy subjects from an area of nonendemicity. Using the combined T-cell responses toward four of these peptides, all paucibacillary patients and 13 out of 14 HHC were detected without compromising specificity. The peptides contain HLA binding motifs for various HLA class I and II alleles, thereby meeting an important requirement for the applicability of diagnostic tools in genetically diverse populations. Thus, this study provides the first evidence for the possibility of immunodiagnostics for leprosy based on mixtures of peptides recognized in the context of different HLA alleles.

scholarly journals From Genome-Based In Silico Predictions to Ex Vivo Verification of Leprosy Diagnosis

2009 ◽  
Vol 16 (3) ◽  
pp. 352-359 ◽  
Author(s):  
Annemieke Geluk ◽  
John S. Spencer ◽  
Kidist Bobosha ◽  
Maria C. V. Pessolani ◽  
Geraldo M. B. Pereira ◽  
...  
Keyword(s):  
T Cell ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
Immunoglobulin M ◽  
Diagnostic Tools ◽  
Cell Responses ◽  
Household Contacts ◽  
Diagnostic Potential ◽  
Human T Cell ◽  
Leprosy Patients

ABSTRACT The detection of hundreds of thousands of new cases of leprosy every year suggests that transmission of Mycobacterium leprae infection still continues. Unfortunately, tools for identification of asymptomatic disease and/or early-stage M. leprae infection (likely sources of transmission) are lacking. The recent identification of M. leprae-unique genes has allowed the analysis of human T-cell responses to novel M. leprae antigens. Antigens with the most-promising diagnostic potential were tested for their ability to induce cytokine secretion by using peripheral blood mononuclear cells from leprosy patients and controls in five different areas where leprosy is endemic; 246 individuals from Brazil, Nepal, Bangladesh, Pakistan, and Ethiopia were analyzed for gamma interferon responses to five recombinant proteins (ML1989, ML1990, ML2283, ML2346, and ML2567) and 22 synthetic peptides. Of these, the M. leprae-unique protein ML1989 was the most frequently recognized and ML2283 the most specific for M. leprae infection/exposure, as only a limited number of tuberculosis patients responded to this antigen. However, all proteins were recognized by a significant number of controls in areas of endemicity. T-cell responses correlated with in vitro response to M. leprae, suggesting that healthy controls in areas where leprosy is endemic are exposed to M. leprae. Importantly, 50% of the healthy household contacts and 59% of the controls in areas of endemicity had no detectable immunoglobulin M antibodies to M. leprae-specific PGL-I but responded in T-cell assays to ≥1 M. leprae protein. T-cell responses specific for leprosy patients and healthy household contacts were observed for ML2283- and ML0126-derived peptides, indicating that M. leprae peptides hold potential as diagnostic tools. Future work should concentrate on the development of a sensitive and field-friendly assay and identification of additional peptides and proteins that can induce M. leprae-specific T-cell responses.

scholarly journals Peptides Derived fromMycobacterium lepraeML1601c Discriminate between Leprosy Patients and Healthy Endemic Controls

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Kidist Bobosha ◽  
Jolien J. van der Ploeg-van Schip ◽  
Danuza A. Esquenazi ◽  
Marjorie M. Guimarães ◽  
Marcia V. Martins ◽  
...  
Keyword(s):  
Whole Blood ◽  
Early Stage ◽  
Mycobacterium Leprae ◽  
Diagnostic Tools ◽  
Whole Blood Assay ◽  
Cell Responses ◽  
Household Contacts ◽  
Blood Assay ◽  
Diagnostic Potential ◽  
Leprosy Patients

The stable incidence of new leprosy cases suggests that transmission of infection continues despite worldwide implementation of MDT. Thus, specific tools are needed to diagnose early stageMycobacterium lepraeinfection, the likely sources of transmission.M. lepraeantigens that induce T-cell responses inM. lepraeexposed and/or infected individuals thus are major targets for new diagnostic tools. Previously, we showed that ML1601c was immunogenic in patients and healthy household contacts (HHC). However, some endemic controls (EC) also recognized this protein. To improve the diagnostic potential, IFN-γresponses to ML1601c peptides were assessed using PBMC from Brazilian leprosy patients and EC. Five ML1601c peptides only induced IFN-γin patients and HHC. Moreover, 24-hour whole-blood assay (WBA), two ML1601c peptides could assess the level ofM. lepraeexposure in Ethiopian EC. Beside IFN-γ, also IP-10, IL-6, IL-1β, TNF-α, and MCP-1 were increased in EC from areas with high leprosy prevalence in response to these ML1601c peptides. Thus, ML1601c peptides may be useful for differentiatingM. lepraeexposed or infected individuals and can also be used to indicate the magnitude ofM. lepraetransmission even in the context of various HLA alleles as present in these different genetic backgrounds.

scholarly journals Lsr2 Peptides of Mycobacterium leprae Show Hierarchical Responses in Lymphoproliferative Assays, with Selective Recognition by Patients with Anergic Lepromatous Leprosy

2011 ◽  
Vol 80 (2) ◽  
pp. 742-752 ◽  
Author(s):  
Mehervani Chaduvula ◽  
A. Murtaza ◽  
Namita Misra ◽  
N. P. Shankar Narayan ◽  
V. Ramesh ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Responses ◽  
Mycobacterium Leprae ◽  
Lepromatous Leprosy ◽  
Healthy Controls ◽  
Content Type ◽  
Tuberculosis Patients ◽  
Cell Responses ◽  
Leprosy Patients

ABSTRACTLsr2 protein ofMycobacterium lepraewas shown earlier to elicit B and T cell responses in leprosy patients (20, 28). Lymphoproliferation toM. lepraeand Lsr2 antigens was observed in >70% of tuberculoid (T) patients and in 16 and 34% of lepromatous (L) patients, respectively. We focused on theM. lepraenonresponders in the lepromatous group using 22 synthetic Lsr2 peptides (end-to-end peptides A to F and overlapping peptides p1 to p16) inin vitroT cell responses. A total of 125 leprosy and 13 tuberculosis patients and 19 healthy controls from the area of endemicity (here, healthy controls, or HC) were investigated. The highest responses were observed (67 to 100%) in HC for all peptides except p1 to p3, and the lowest was observed in tuberculosis patients. Significant differences in lymphoproliferation were observed in T, L, and HC groups (analysis of variance [ANOVA],P= 0.000 to 0.015) for all end-to-end peptides except B and for p5 and p7 to p10. Hierarchical recognition between lepromatous and tuberculoid leprosy was noted for p8 (P< 0.05) and between the HC and L groups for p7 to p10, p15, and p16 (P< 0.005 toP< 0.02). Significant lymphoproliferation was observed to peptides A to F and p1 to p9, p11, p12, p15, p16 (P= 0.000 to 0.001) with 40% responding to peptides C and p16 in L patients. Lepromatous patients also showed significantly higher levels of a gamma interferon (IFN-γ) response to peptide C than to other peptides (P< 0.05). Major histocompatibility complex (MHC) class II bias for peptide recognition was not observed. These studies indicate that Lsr2 has multiple T cell epitopes that inducein vitroT cell responses in the highly infective lepromatous leprosy patients.

scholarly journals Public T-cell epitopes shared among SARS-CoV-2 variants are presented on prevalent HLA class I alleles

2021 ◽  
Author(s):  
Saskia Meyer ◽  
Isaac Blaas ◽  
Ravi Chand Bollineni ◽  
Marina Delic-Sarac ◽  
Trung T Tran ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
T Cell Responses ◽  
Hla Class I ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Class I ◽  
T Cell Epitopes ◽  
Low Frequencies ◽  
Cell Responses

T-cell epitopes with broad population coverage may form the basis for a new generation of SARS-CoV-2 vaccines. However, published studies on immunoprevalence are limited by small test cohorts, low frequencies of antigen-specific cells and lack of data correlating eluted HLA ligands with T-cell responsiveness. Here, we investigate CD8 T-cell responses to 48 peptides eluted from prevalent HLA alleles, and an additional 84 predicted binders, in a large cohort of convalescents (n=83) and pre-pandemic control samples (n=19). We identify nine conserved SARS-CoV-2 specific epitopes restricted by four of the most prevalent HLA class I alleles in Caucasians, to which responding CD8 T cells are detected in 70-100% of convalescents expressing the relevant HLA allele, including two novel epitopes. We find a strong correlation between immunoprevalence and immunodominance. Using a new algorithm, we predict that a vaccine including these epitopes would induce a T cell response in 83% of Caucasians. Significance Statement: Vaccines that induce broad T-cell responses may boost immunity as protection from current vaccines against SARS-CoV-2 is waning. From a manufacturing standpoint, and to deliver the highest possible dose of the most immunogenic antigens, it is rational to limit the number of epitopes to those inducing the strongest immune responses in the highest proportion of individuals in a population. Our data show that the CD8 T cell response to SARS-CoV-2 is more focused than previously believed. We identify nine conserved SARS-CoV-2 specific CD8 T cell epitopes restricted by four of the most prevalent HLA class I alleles in Caucasians and demonstrate that seven of these are endogenously presented.

scholarly journals Recruitment of highly functional SARS-CoV-2-specific CD8+ T cell receptors mediating cytotoxicity of virus-infected target cells in non-severe COVID-19

2021 ◽  
Author(s):  
Karolin I. Wagner ◽  
Laura M. Mateyka ◽  
Sebastian Jarosch ◽  
Vincent Grass ◽  
Simone Weber ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Hla Class I ◽  
Cd8 T Cell ◽  
Target Cells ◽  
Cell Responses ◽  
Cell Immunity ◽  
Engineered T Cells

T cell immunity is crucial for the control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and has been widely characterized on a quantitative level. In contrast, the quality of such T cell responses has been poorly investigated, in particular in the case of CD8+ T cells. Here, we explored the quality of SARS-CoV-2-specific CD8+ T cell responses in individuals who recovered from mild symptomatic infections, through which protective immunity should develop, by functional characterization of their T cell receptor (TCR) repertoire. CD8+ T cell responses specific for SARS-CoV-2-derived epitopes were low in frequency but could be detected robustly early as well as late - up to twelve months - after infection. A pool of immunodominant epitopes, which accurately identified previous SARSCoV- 2 infections, was used to isolate TCRs specific for epitopes restricted by common HLA class I molecules. TCR-engineered T cells showed heterogeneous functional avidity and cytotoxicity towards virus-infected target cells. High TCR functionality correlated with gene signatures of T cell function and activation that, remarkably, could be retrieved for each epitope:HLA combination and patient analyzed. Overall, our data demonstrate that highly functional HLA class I TCRs are recruited and maintained upon mild SARS-CoV-2 infection. Such validated epitopes and TCRs could become valuable tools for the development of diagnostic tests determining the quality of SARS-CoV-2-specific CD8+ T cell immunity, and thereby investigating correlates of protection, as well as to restore functional immunity through therapeutic transfer of TCR-engineered T cells.

scholarly journals Strong HLA Class I–Restricted T Cell Responses in Dengue Hemorrhagic Fever: A Double‐Edged Sword?

2001 ◽  
Vol 184 (11) ◽  
pp. 1369-1373 ◽  
Author(s):  
Hsin Loke ◽  
Delia B. Bethell ◽  
C. X. T. Phuong ◽  
Minh Dung ◽  
Joerg Schneider ◽  
...  
Keyword(s):  
T Cell ◽  
Dengue Hemorrhagic Fever ◽  
T Cell Responses ◽  
Hla Class I ◽  
Hemorrhagic Fever ◽  
Class I ◽  
Cell Responses

T cell response to two immunodominant proteolipid protein (PLP) peptides in multiple sclerosis patients and healthy controls

1996 ◽  
Vol 1 (5) ◽  
pp. 270-278 ◽  
Author(s):  
CM Pelfrey ◽  
LR Tranquill ◽  
AB Vogt ◽  
HF McFarland
Keyword(s):  
Multiple Sclerosis ◽  
T Cell ◽  
Demyelinating Disease ◽  
T Cell Responses ◽  
Proteolipid Protein ◽  
T Cell Response ◽  
Healthy Controls ◽  
Cell Responses ◽  
Hla Binding ◽  
Multiple Sclerosis Patients

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system in which autoimmune T lymphocytes reacting with myelin antigens are believed to play a pathogenic role. Since HLA binding is involved in the selection of T cell responses, we have examined PLP peptide binding to HLA DR2, an HLA allele frequently found in MS patients. Both PLP 40–60 and PLP 89–106 show significant, high affinity binding to HLA DR2. We then tested whether responses to PLP peptides 40–60 and 89–106 are elevated in multiple sclerosis patients compared to matched controls. We also analysed T cell responses to MBP 87–106, which is considered to be the immunodominant region of MBP in humans. Here we demonstrate heterogenous T cell responses to PLP 40–60, PLP 89–106 and MBP 87–106 in both MS patients and controls. The overall number of TCL and the HLA restriction of those TCL did not vary significantly in the two groups. PLP 40–60 specific cytolytic TCL were increased in MS patients, whereas healthy controls had increased percentages of cytolytic TCL responding to PLP 89–106 and MBP 87–106. Although the data presented here shows heterogenous responses in T cell numbers, differences in numbers and specificity of cytolytic cells could be involved in the pathogenesis of autoimmune demyelinating disease.

HLA Class I Ligandome Analysis In Acute Myeloid Leukemia – Novel T-Cell Epitopes For Peptide-Based Immunotherapy

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5431-5431
Author(s):  
Stickel S. Juliane ◽  
Claudia Berlin ◽  
Daniel J. Kowalewski ◽  
Heiko Schuster ◽  
Lothar Kanz ◽  
...  
Keyword(s):  
T Cell ◽  
Conflicts Of Interest ◽  
Peptide Vaccine ◽  
T Cell Responses ◽  
Hla Class I ◽  
Class I ◽  
Isolation And Identification ◽  
Cell Responses ◽  
Healthy Donors ◽  
Hla Ligands

Abstract Data regarding the graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation (SCT) and donor lymphocyte infusion strongly suggest that T lymphocytes play a major role in the rejection of leukemic cells. Immunotherapy directed against leukemia- associated antigens might elicit specific immune responses that may serve to eliminate minimal residual disease after chemotherapy, or enhance the GVL effect after SCT. To achieve this goal there is need to identify appropriate leukemia associated HLA ligands, which are able to induce specific T cell responses. We here aimed to characterize the HLA class I ligandome in AML patients to provide novel tumor associated antigens (TAA) for peptide-based immunotherapy employing our recently implemented approach of direct isolation and identification of naturally presented HLA ligands by affinity chromatography and mass spectrometry (LC-MS/MS) in AML (Stickel et.al., abstract in Blood 2012). Absolute HLA surface expression on AML cells and autologous monocytes and granulocytes was quantified by flow cytometry. HLA class I ligands were isolated from AML cells as well as bone marrow and peripheral blood mononuclear cell (BMNCs/PBMCs) of healthy donors. LC-MS/MS peptide analysis provided qualitative and semi-quantitative information regarding the composition of the respective ligandomes. Comparative analysis of malignant and benign samples served to identify ligandome-derived TAA (LiTAA) and to select peptide vaccine candidates. The most abundantly detected peptide candidates were checked for immunogenicity by ELISpot and confirmed by intracellular interferon-g staining of CD8+ T-cells. Meanwhile 15 AML patients (8 FLT3-ITD mutant) and 35 healthy donors were analyzed. We observed overexpression of HLA class I and II on AML cells as compared to autologous monocytes and granulocytes, with the level of significance reached for HLA class II (p=0,04). A total of more than 12,000 AML derived HLA ligands representing >6,000 different source proteins were identified; of which 2,220 were exclusively represented in AML, but not in healthy PBMC/BMNC. Data mining for broadly represented LiTAA pinpointed 98 TAA as most promising targets. HLA ligands derived from these TAA were presented exclusively on more than 33% of all analyzed AML samples, amongst them already described TAA (e.g. JUP, FAF1) as well as several new leukemia-associated proteins (e.g. MTCH2, METTL7A). Subset analysis of the FLT3-ITD positive AML cohort revealed 21 LiTAA presented exclusively on more than 50% of FLT3-ITD positive AML cases. Additional screening for HLA ligands derived from described leukemia associated antigens revealed overrepresentation for e.g. FLT3, NUSAP, RHAMM and RGS5. Specific CD8+ T cell responses were detected against two A*03 epitope pools (pool 1: APLP2, DKGZ, FAF1, MTCH2; pool 2: KLF2, METTL7A, VCIP1, WIPI1) in AML patients. Notably, the chosen A*03 epitope pools did not elicit specific responses of CTL from healthy donors. Taken together, our HLA class I ligandome analysis in AML for the first time identified naturally presented HLA ligands from patients including a vast array of new leukemia associated antigens representing promising targets for a multipeptide-based immunotherapy approach in AML. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Effective T-Cell Responses Select Human Immunodeficiency Virus Mutants and Slow Disease Progression

2007 ◽  
Vol 81 (12) ◽  
pp. 6742-6751 ◽  
Author(s):  
A. J. Frater ◽  
H. Brown ◽  
A. Oxenius ◽  
H. F. Günthard ◽  
B. Hirschel ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Disease Progression ◽  
T Cell Responses ◽  
Hla Class I ◽  
Class I ◽  
Cell Responses ◽  
Hla Class I Molecules ◽  
Immunodeficiency Virus ◽  
African Patients

ABSTRACT The possession of some HLA class I molecules is associated with delayed progression to AIDS. The mechanism behind this beneficial effect is unclear. We tested the idea that cytotoxic T-cell responses restricted by advantageous HLA class I molecules impose stronger selection pressures than those restricted by other HLA class I alleles. As a measure of the selection pressure imposed by HLA class I alleles, we determined the extent of HLA class I-associated epitope variation in a cohort of European human immunodeficiency virus (HIV)-positive individuals (n = 84). We validated our findings in a second, distinct cohort of African patients (n = 516). We found that key HIV epitopes restricted by advantageous HLA molecules (B27, B57, and B51 in European patients and B5703, B5801, and B8101 in African patients) were more frequently mutated in individuals bearing the restricting HLA than in those who lacked the restricting HLA class I molecule. HLA alleles associated with clinical benefit restricted certain epitopes for which the consensus peptides were frequently recognized by the immune response despite the circulating virus's being highly polymorphic. We found a significant inverse correlation between the HLA-associated hazard of disease progression and the mean HLA-associated prevalence of mutations within epitopes (P = 0.028; R 2 = 0.34). We conclude that beneficial HLA class I alleles impose strong selection at key epitopes. This is revealed by the frequent association between effective T-cell responses and circulating viral escape mutants and the rarity of these variants in patients who lack these favorable HLA class I molecules, suggesting a significant pressure to revert.

Sign in / Sign up

Export Citation Format

Share Document