scholarly journals Identification of Rhodococcus equi lipids recognized by host cytotoxic T lymphocytes

Microbiology ◽  
2010 ◽  
Vol 156 (6) ◽  
pp. 1836-1847 ◽  
Author(s):  
Seth P. Harris ◽  
Nagatoshi Fujiwara ◽  
Robert H. Mealey ◽  
Debra C. Alperin ◽  
Takashi Naka ◽  
...  
Keyword(s):  
Cell Wall ◽  
T Lymphocytes ◽  
Mhc Class I ◽  
Cytotoxic T Lymphocytes ◽  
Rhodococcus Equi ◽  
Class I ◽  
Interleukin 4 ◽  
Target Cells ◽  
Immune Recognition ◽  
Specific Ctls

Immune adult horses have CD8+ cytotoxic T lymphocytes (CTLs) that recognize and lyse Rhodococcus equi-infected cells in an equine lymphocyte alloantigen (ELA)-A [classical major histocompatibility complex (MHC) class I]-unrestricted fashion. As protein antigens are MHC class I-restricted, the lack of restriction suggests that the bacterial antigens being recognized by the host are not proteins. The goals of this study were to test the hypothesis that these CTLs recognize unique R. equi cell-wall lipids related to mycobacterial lipids. Initial experiments showed that treatment of soluble R. equi antigen with broadly reactive proteases did not significantly diminish the ability of the antigen to stimulate R. equi-specific CTLs. R. equi-specific CTLs were also shown to lyse target cells (equine macrophages) pulsed with an R. equi lipid extract. Analysis of the R. equi lipid by TLC and MS (MALDI-TOF and ES) indicated that the extracted antigen consisted of three primary fractions: trehalose monomycolate (TMM), trehalose dimycolate (TDM) and cardiolipin (CL). ELA-A-mismatched cells pulsed with purified TMM and CL, but not the TDM fraction, were recognized and lysed by R. equi-specific CTLs. Because of their role in immune clearance and pathogenesis, transcription of the cytokines gamma interferon (IFN-γ) and interleukin-4 (IL-4) was also measured in response to R. equi lipids by using real-time PCR; elevated IFN-γ, but not IL-4, was associated with host clearance of the bacteria. The whole-cell R. equi lipid and all three R. equi lipid fractions resulted in marked increases in IFN-γ transcription, but no increase in IL-4 transcription. Together, these data support the hypothesis that immune recognition of unique lipids in the bacterial cell wall is an important component of the protective immune response to R. equi. The results also identify potential lipid antigens not previously shown to be recognized by CTLs in an important, naturally occurring actinomycete bacterial pathogen.

scholarly journals Rhodococcus equi-Infected Macrophages Are Recognized and Killed by CD8+ T Lymphocytes in a Major Histocompatibility Complex Class I-Unrestricted Fashion

2004 ◽  
Vol 72 (12) ◽  
pp. 7073-7083 ◽  
Author(s):  
Kristin M. Patton ◽  
Travis C. McGuire ◽  
Darrilyn G. Fraser ◽  
Stephen A. Hines
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Lymphocytes ◽  
Mhc Class I ◽  
Rhodococcus Equi ◽  
Class I ◽  
Cell Phenotype ◽  
Target Cells ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

ABSTRACT The goal of this research was to examine the role of cytotoxic T lymphocytes (CTL) in the control of Rhodococcus equi and specifically to determine if R. equi-specific CD8+ CTL occurred in the blood of immune horses. Equine peripheral blood mononuclear cells stimulated with antigen-presenting cells either infected with R. equi or exposed to soluble R. equi antigen lysed R. equi-infected target cells. Lysis was decreased to background by depletion of either CD2+ or CD3+ cells, indicating that the effector cell had a T-lymphocyte, but not NK cell, phenotype. Stimulation induced an increased percentage of CD8+ T cells in the effector population, and depletion of CD8+ T cells resulted in significantly decreased lysis of infected targets. Killing of R. equi-infected macrophages by effector cells was equally effective against autologous and equine leukocyte antigen A (classical major histocompatibility complex [MHC] class I) mismatched targets. To evaluate potential target antigens, target cells were infected with either virulent (80.6-kb plasmid-containing) or avirulent (plasmid-cured) R. equi. The degree of lysis was not altered by the presence of the plasmid, providing evidence that the virulence plasmid, which is required for survival within macrophages, was not necessary for recognition and killing of R. equi-infected cells. These data indicate that immunocompetent adult horses develop R. equi-specific CD8+ CTL, which may play a role in immunity to R. equi. The apparent lack of restriction via classical MHC class I molecules suggests a novel or nonclassical method of antigen processing and presentation, such as presentation by CD1 or other nonclassical MHC molecules.

scholarly journals Detection of major histocompatibility complex class I-restricted, HIV- specific cytotoxic T lymphocytes in the blood of infected hemophiliacs

Blood ◽  
1989 ◽  
Vol 73 (7) ◽  
pp. 1909-1914 ◽  
Author(s):  
RA Koup ◽  
JL Sullivan ◽  
PH Levine ◽  
D Brettler ◽  
A Mahr ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Mhc Class I ◽  
Cytotoxic T Lymphocytes ◽  
Mononuclear Cells ◽  
Nk Cell ◽  
Class I ◽  
Gene Products ◽  
Major Histocompatibility ◽  
Peripheral Blood Mononuclear ◽  
Hiv 1

Abstract Major histocompatibility (MHC)-restricted, human immunodeficiency virus type one (HIV-1)-specific, cytotoxic T lymphocytes (CTLs) were detected in the peripheral blood mononuclear cells (PBMCs) of HIV-1-infected individuals. Using a system of autologous B and T lymphoblastoid cell lines infected with recombinant vaccinia vectors (VVs) expressing HIV-1 gene products, we were able to detect HIV-1-specific cytolytic responses in the PBMCs of 88% of HIV-1-seropositive hemophiliac patients in the absence of in vitro stimulation. These cytolytic responses were directed against both HIV-1 envelope and gag gene products. The responses were resistant to natural killer (NK) cell depletion and were inhibited by monoclonal antibodies (MoAbs) to the T cell receptor, CD8 surface antigens, and MHC class I antigens, suggesting a classical MHC class I restricted, virus-specific CTL response.

Generation of Antigen Specific Cytotoxic T Lymphocytes (CTL) by Dendritic Cells (DCs) Transfected with In Vitro Transcribed (IVT) SART-1 and WT-1 mRNA.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3859-3859
Author(s):  
Anri Saito ◽  
Miwako Narita ◽  
Toshio Yano ◽  
Naoko Sato ◽  
Asuka Sekiguchi ◽  
...  
Keyword(s):  
Mhc Class I ◽  
Tumor Antigen ◽  
Hla Class I ◽  
Class Ii ◽  
Class I ◽  
Target Cells ◽  
Mhc Restriction ◽  
Specific Ctls ◽  
Specific Antigens

Abstract Transfection with tumor antigen RNA is one of the promising tools not only because of a possible sufficient amplification of tumor antigen RNA but also because of the absence of antigen peptides-associated MHC restriction. Several succeeded experiments about generation of CTLs using DCs transfeced in vitro transcribed (IVT) cancer specific antigen mRNA such as PSA, CEA, hTERT and MUC-1 have been reported in these a few years. In addition, recent reports about the simultaneous presentation of peptides in both MHC class I and class II molecules on DCs after mRNA electroporation show another superiority of mRNA transfection into DCs. In this presentation, we demonstrate successful generation of tumor antigen specific CTLs using with DCs transfected with IVT mRNA such as SART-1 and WT-1 by electroporation. This is the first report about the generation of SART-1 and WT-1 specific CTLs by using mRNA transfected DCs. [Methods] HLA-A24 positive human PB CD14+ cell-derived DCs were transfected with IVT mRNA (SART-1and WT-1) by electroporation. MRNA transfected DCs were co-cultured with autologous lymphocytes. The bulk co-cultures were re-stimulated several times with same DCs. CD8+ cells were separated and CTL activity was evaluated by 51chromium release assay. To determine whether the induced CTL cells could recognize the target cells in an HLA class I restricted manner, anti-HLA class I monoclonal antibodies were utilized to block the cytotoxicity of effectors. [Results] Electroporation of mRNA showed no effect on the surface phenotypes and antigen presenting ability of DCs. In addition to the demonstration of efficient transfection of M1 mRNA into DCs by using RT-PCR, which eliminated the amplification of transfected mRNA by the treatment with RNase before RNA extraction from the transfected cells, we identified the definite expression of WT-1 protein in the cytoplasm of DCs by using immunoblotting. CTL assay indicated that 1) DCs transfected with mRNA stimulated the generation of antigen-specific CTLs which are capable of lysing autologous DCs transfected with the same mRNA. 2) CTLs also demonstrated cytotoxic ability against cell lines such as KE-4 presenting SART-1 peptides on HLA-A24, MEGO1 presenting WT-1 peptides on MHC class I, and HLA-A24 cDNA transfected T2 which were used as target cells after co- incubation with 9 mer SART-1 peptides with strong affinity to HLA-A24. 3) Each cytotoxicities were markedly blocked after co-incubation of target cells with anti-MHC class I antibody and not inhibited with anti-MHC class II antibody. [Conclusion] Our results showed that IVT mRNA-transfected DCs which is constructed non-virally have a highly efficient ability to stimulate specific T-cell immunity against tumor. Unlike peptide- or tumor cells extract-pulsed DCs based vaccines, anti-tumor immunotherapy using the DCs transfected with antigen mRNA could be extended to a wide range of patients who have previously been excluded from clinical trials for the reason of the un-identification of tumor specific antigens, for the reason of the impossibility of obtaining sufficient tumor specimens, or for the reason of MHC restriction of the tumor specific antigens.

In Vitro Induction of Specific Cytotoxic T Lymphocytes Using Recombinant Single-Chain MHC Class I/Peptide Complexes

1998 ◽  
Vol 21 (4) ◽  
pp. 283-294 ◽  
Author(s):  
Yu-Chun Lone ◽  
Iris Motta ◽  
Estelle Mottez ◽  
Yannik Guilloux ◽  
Annick Lim ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Mhc Class I ◽  
Cytotoxic T Lymphocytes ◽  
Class I ◽  
Single Chain ◽  
Peptide Complexes ◽  
In Vitro Induction

scholarly journals Effective and selective immune surveillance of the brain by MHC class I-restricted cytotoxic T lymphocytes

2003 ◽  
Vol 33 (5) ◽  
pp. 1174-1182 ◽  
Author(s):  
Julie Cabarrocas ◽  
Jan Bauer ◽  
Eliane Piaggio ◽  
Roland Liblau ◽  
Hans Lassmann
Keyword(s):  
T Lymphocytes ◽  
Mhc Class I ◽  
Cytotoxic T Lymphocytes ◽  
Immune Surveillance ◽  
Class I ◽  
The Brain

scholarly journals Gag Protein Epitopes Recognized by ELA-A-Restricted Cytotoxic T Lymphocytes from Horses with Long-Term Equine Infectious Anemia Virus Infection

1998 ◽  
Vol 72 (12) ◽  
pp. 9612-9620 ◽  
Author(s):  
Wei Zhang ◽  
Scott M. Lonning ◽  
Travis C. McGuire
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Equine Infectious Anemia Virus ◽  
Class I ◽  
Target Cells ◽  
Ctl Epitopes ◽  
Peptide Epitopes ◽  
Equine Infectious Anemia ◽  
Anemia Virus

ABSTRACT Most equine infectious anemia virus (EIAV)-infected horses have acute clinical disease, but they eventually control the disease and become lifelong carriers. Cytotoxic T lymphocytes (CTL) are considered an important immune component in the control of infections with lentiviruses including EIAV, but definitive evidence for CTL in the control of disease in carrier horses is lacking. By using retroviral vector-transduced target cells expressing different Gag proteins and overlapping synthetic peptides of 16 to 25 amino acids, peptides containing at least 12 Gag CTL epitopes recognized by virus-stimulated PBMC from six long-term EIAV-infected horses were identified. All identified peptides were located within Gag matrix (p15) and capsid (p26) proteins, as no killing of target cells expressing p11 and p9 occurred. Each of the six horses had CTL recognizing at least one Gag epitope, while CTL from one horse recognized at least eight different Gag epitopes. None of the identified peptides were recognized by CTL from all six horses. Two nonamer peptide epitopes were defined from Gag p26; one (18a) was likely restricted by class I equine leukocyte alloantigen A5.1 (ELA-A5.1) molecules, and the other (28b-1) was likely restricted by ELA-A9 molecules. Sensitization of equine kidney target cells for CTLm killing required 10 nM peptide 18a and 1 nM 28b-1. The results demonstrated that diverse CTL responses against Gag epitopes were generated in long-term EIAV-infected horses and indicated that ELA-A class I molecules were responsible for the diversity of CTL epitopes recognized. This information indicates that multiple epitopes or whole proteins will be needed to induce CTL in horses with different ELA-A alleles in order to evaluate their role in controlling EIAV.

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