scholarly journals Maintenance of viral suppression in HIV-1–infected HLA-B*57+ elite suppressors despite CTL escape mutations

2006 ◽  
Vol 203 (5) ◽  
pp. 1357-1369 ◽  
Author(s):  
Justin R. Bailey ◽  
Thomas M. Williams ◽  
Robert F. Siliciano ◽  
Joel N. Blankson
Keyword(s):  
T Cell ◽  
Viral Suppression ◽  
Selective Pressure ◽  
De Novo ◽  
Interleukin 2 ◽  
Cd8 T Cell ◽  
Plasma Virus ◽  
Low Level ◽  
Ctl Escape ◽  
Elite Suppressors

Rare human immunodeficiency virus 1–infected individuals, termed elite suppressors (ES), maintain plasma virus levels of <50 copies/ml and normal CD4 counts without therapy. The major histocompatibility complex class I allele group human histocompatibility leukocyte antigen (HLA)-B*57 is overrepresented in this population. Mutations in HLA-B*57–restricted epitopes have been observed in ES, but their significance has remained unclear. Here we investigate the extent and impact of cytotoxic T lymphocyte (CTL) escape mutations in HLA-B*57+ ES. We provide the first direct evidence that most ES experience chronic low level viremia. Sequencing revealed a striking discordance between the genotypes of plasma virus and archived provirus in resting CD4+ T cells. Mutations in HLA-B*57–restricted Gag epitopes were present in all viruses from plasma but were rare in proviruses, suggesting powerful selective pressure acting at these epitopes. Surprisingly, strong CD8+ T cell interferon-γ responses were detected against some mutant epitopes found in plasma virus, suggesting the development of de novo responses to viral variants. In some individuals, relative CD8+ T cell interleukin-2 responses showed better correlation with the selection observed in vivo. Thus, analysis of low level viremia reveals an unexpectedly high level of CTL escape mutations reflecting selective pressure acting at HLA-B*57–restricted epitopes in ES. Continued viral suppression probably reflects CTL responses against unmutated epitopes and residual or de novo responses against epitopes with escape mutations.

scholarly journals Control of HIV-1 in Elite Suppressors despite Ongoing Replication and Evolution in Plasma Virus

2010 ◽  
Vol 84 (14) ◽  
pp. 7018-7028 ◽  
Author(s):  
Karen A. O'Connell ◽  
Timothy P. Brennan ◽  
Justin R. Bailey ◽  
Stuart C. Ray ◽  
Robert F. Siliciano ◽  
...  
Keyword(s):  
Selective Pressure ◽  
De Novo ◽  
Cytotoxic T Lymphocyte ◽  
Hla Class I ◽  
Latent Reservoir ◽  
Elite Controllers ◽  
Plasma Virus ◽  
Longitudinal Plasma ◽  
Elite Suppressors ◽  
Hiv 1

ABSTRACT A subset of HIV-1-infected patients known as elite controllers or suppressors (ES) control the virus naturally. We have previously demonstrated sequence discordance between proviral and plasma gag clones in ES, much of which can be attributed to selective pressure from the host (J. R. Bailey, T. M. Williams, R. F. Siliciano, and J. N. Blankson, J. Exp. Med. 203:1357-1369, 2006). However, it is not clear whether ongoing viral replication continues in ES once the control of viremia has been established or whether selective pressure impacts this evolution. The cytotoxic T-lymphocyte (CTL) response in ES often targets Gag and frequently is superior to that of HIV-1 progressors, partially due to the HLA class I alleles B*57/5801 and B*27, which are overrepresented in ES. We therefore examined longitudinal plasma and proviral gag sequences from HLA-B*57/5801 and -B*27 ES. Despite the highly conserved nature of gag, we observed clear evidence of evolution in the plasma virus, largely due to synonymous substitutions. In contrast, evolution was rare in proviral clones, suggesting that ongoing replication in ES does not permit the significant reseeding of the latent reservoir. Interestingly, there was little continual evolution in CTL epitopes, and we detected de novo CTL responses to autologous viral mutants. Thus, some ES control viremia despite ongoing replication and evolution.

scholarly journals Evidence of CD8+ T-Cell-Mediated Selective Pressure on Human Immunodeficiency Virus Type 1 nef in HLA-B*57+ Elite Suppressors

2008 ◽  
Vol 83 (1) ◽  
pp. 88-97 ◽  
Author(s):  
Justin R. Bailey ◽  
Timothy P. Brennan ◽  
Karen A. O'Connell ◽  
Robert F. Siliciano ◽  
Joel N. Blankson
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Selective Pressure ◽  
Plasma Virus ◽  
Viral Loads ◽  
Immunodeficiency Virus ◽  
Elite Suppressors ◽  
Hiv 1

ABSTRACT Elite suppressors (ES) are human immunodeficiency virus type 1 (HIV-1)-infected patients who maintain viral loads of <50 copies/ml without treatment. The observation that the HLA-B*57 allele is overrepresented in these patients implies that HIV-1-specific CD8+ T cells play a key role in suppressing viral replication. We have previously shown that while CD8+ T-cell escape mutations are rarely seen in proviral Gag sequences in resting CD4+ T cells from peripheral blood, they are present in every clone amplified from the low levels of free virus in the plasma of HLA-B*57+ ES. In this study, we compared the pattern of mutations in Nef sequences amplified from peripheral blood CD4+ T cells and from plasma virus. We show that Nef mutations are present in plasma virus but are rare in the cellular sequences and provide evidence that these plasma Nef variants represent novel escape mutants. The results provide further evidence of CD8+ T-cell-mediated selective pressure on plasma virus in ES and suggest that there must be ongoing HIV-1 replication in spite of the very low viral loads seen for these patients.

Interleukin-2 immunotherapy exerts a differential effect on CD4 and CD8 T cell dynamics

AIDS ◽  
2004 ◽  
Vol 18 (2) ◽  
pp. 211-216 ◽  
Author(s):  
Giulia Marchetti ◽  
Luca Meroni ◽  
Chiara Molteni ◽  
Alessandra Bandera ◽  
Fabio Franzetti ◽  
...  
Keyword(s):  
T Cell ◽  
Differential Effect ◽  
Interleukin 2 ◽  
Cd8 T Cell ◽  
Cell Dynamics

scholarly journals The TLR9 ligand CpG ODN 2006 is a poor adjuvant for the induction of de novo CD8+ T-cell responses in vitro

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Laura Papagno ◽  
Nozomi Kuse ◽  
Anna Lissina ◽  
Emma Gostick ◽  
David A. Price ◽  
...  
Keyword(s):  
T Cell ◽  
De Novo ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cpg Odn ◽  
Cell Responses ◽  
Tlr9 Ligand

CD4 T lymphocytes are primed to express Fas ligand by CD4 cross-linking and to contribute to CD8 T-cell apoptosis via Fas/FasL death signaling pathway

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 195-202 ◽  
Author(s):  
Masaki Tateyama ◽  
Naoki Oyaizu ◽  
Thomas W. McCloskey ◽  
Soe Than ◽  
Savita Pahwa
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Interleukin 2 ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Cross Linking ◽  
Induced Apoptosis ◽  
Hiv 1

CD4 molecules serve as coreceptors for the T-cell receptor (TCR)/CD3 complex that are engaged coordinately with TCR and facilitate antigen-specific T-cell activation leading to interleukin 2 (IL-2) production and proliferation. However, cross-ligation of CD4 molecules prior to TCR stimulation has been shown to prime CD4 T cells to undergo apoptosis. Although in vivo and in vitro experiments have implicated the involvement of Fas/FasL interaction in this CD4 cross-linking (CD4XL)-induced apoptosis, detailed mechanisms to account for cell death induction have not been elucidated. In the present study, we demonstrate that CD4XL in purified T cells not only led to Fas up-regulation but also primed CD4 T cells to express FasL upon CD3 stimulation and rendered the T cells susceptible to Fas-mediated apoptosis. Notably, in addition to CD4+ T cells, CD4XL-induced sensitization for apoptosis was observed in CD8+ T cells as well and was associated with Bcl-x down-modulation. Both CD4 and CD8 T-cell subsets underwent apoptosis following cell–cell contact with FasL+ CD4 T cells. CD28 costimulation abrogated CD4XL/CD3-induced apoptosis with restoration of IL-2 production and prevented Bcl-x down-modulation. As CD4 molecules are the primary receptors for human immunodeficiency virus 1 (HIV-1), we conclude that HIV-1 envelope mediated CD4XL can lead to the generation of FasL-expressing CD4+ T cells that can lead to apoptosis of CD4 as well as CD8 T cells. These findings implicate a novel mechanism for CD8 T-cell depletion in HIV disease.

Efficacy, safety, and immune activation with pegylated human IL-10 (AM0010) in combination with an anti-PD1 in advanced NSCLC.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 9091-9091
Author(s):  
Deborah Jean Lee Wong ◽  
Jeffrey Gary Schneider ◽  
Raid Aljumaily ◽  
Wolfgang Michael Korn ◽  
Jeffrey R. Infante ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Advanced Nsclc ◽  
De Novo ◽  
Cd8 T Cell ◽  
Outcome Data ◽  
Low Grade

9091 Background: Although IL-10 has anti-inflammatory properties, it stimulates cytotoxicity and proliferation of intratumoral antigen activated CD8+ T cell at higher concentrations. AM0010 is anticipated to activate antigen stimulated, intratumoral CD8 T cells while PD-1 inhibits them, providing the rationale for combining AM0010 and anti-PD-1 antibody. Methods: We treated a cohort of 34 NSCLC pts with AM0010 (10-20mg/kg QD, SC) and a PD-1 inhibitor [pembrolizumab (2mg/kg, q3wk IV; n=5) or nivolumab (3mg/kg, q2wk IV; n=29)]. Tumor responses were assessed by irRC every 8 weeks. Immune responses were measured by analysis of serum cytokines (Luminex), activation of blood derived T cells (FACS) and peripheral T cell clonality (TCR sequencing). Tumor PD-L1 expression was confirmed by IHC (22C3). Results: Pts had a median of 2 prior therapies. Median follow-up is 9.6 mo (range 0.5-77.3) in this fully enrolled cohort. AM0010 plus anti-PD-1 was well-tolerated. TrAEs were reversible and transient, with most being low grade, most commonly fatigue and pyrexia. G3/4 TrAEs were thrombocytopenia (7), anemia (6), fatigue (4), rash (3), pyrexia (2), hypertriglyceridemia (1) and pneumonitis (1). As of Jan. 31 2017, 22 pts had at least 1 tumor assessment. Partial responses (PRs) were observed in 8 pts (36.4%). 17 of these 22 pts had tissue for analysis of percent of tumor cells with PD-L1 expression (22C3): 58.8% had <1%, 17.7% had 1-49% and 23.5% had >50%. Best response data stratified for PD-L1 are shown in the table. Median PFS and OS for the entire cohort have not been reached. Updated outcome data that includes all enrolled pts will be available at the meeting. AM0010 plus anti-PD1 increased serum Th1 cytokines (IL-18, IFNγ), the number and proliferation of PD1+ Lag3+ activated CD8+ T cells and a de-novo oligoclonal expansion of T cell clones in the blood while decreasing TGFβ. Conclusions: AM0010 in combination with anti-PD1 is well-tolerated in advanced NSCLC pts. The efficacy and the observed CD8+ T cell activation is promising. Clinical trial information: NCT02009449. [Table: see text]

scholarly journals Epstein Barr virus epitope/MHC interaction combined with convergent recombination drive selection of diverse T cell receptor α and β repertoires

2020 ◽  
Author(s):  
Anna Gil ◽  
Larisa Kamga ◽  
Ramakanth Chirravuri-Venkata ◽  
Nuray Aslan ◽  
Fransenio Clark ◽  
...  
Keyword(s):  
T Cell ◽  
Viral Infections ◽  
De Novo ◽  
Dominant Role ◽  
Treatment Strategies ◽  
Optimal Strategies ◽  
Cd8 T Cell ◽  
Human Virus ◽  
Tcr Repertoire ◽  
Selection Of

AbstractRecognition modes of individual T cell receptors (TCR) are well studied, but factors driving the selection of TCR repertoires from primary through persistent human virus infections are less well understood. Using deep sequencing, we demonstrate a high degree of diversity of EBV-specific clonotypes in acute infectious mononucleosis. Only 9% of unique clonotypes detected in AIM persisted into convalescence; the majority (91%) of unique clonotypes detected in AIM were not detected in convalescence and were seeming replaced by equally diverse “de-novo” clonotypes. The persistent clonotypes had a greater probability of being generated than non-persistent due to convergence recombination of multiple nucleotide sequences to encode the same amino acid sequence, as well as the use of shorter CDR3 regions with fewer nucleotide additions (i.e. sequences closer to germline). Moreover, the two most immunodominant HLA-A2-restricted EBV epitopes, BRLF1109 and BMLF1280, show highly distinct antigen-specific public (i.e. shared between individuals) features. In fact, TCRα CDR3 motifs played a dominant role, while TCRβ played a minimal role, in the selection of TCR repertoire to an immunodominant EBV epitope, BRLF1. This contrasts with the majority of previously reported repertoires, which appear to be selected either on TCRβ CDR3 interactions with peptide/MHC or in combination with TCRα CDR3. Understanding of how TCR/peptide/MHC complex interactions drive repertoire selection can be used to develop optimal strategies for vaccine design or generation of appropriate adoptive immunotherapies for viral infections in transplant settings or for cancer.ImportanceSeveral lines of evidence suggest that TCRα and β repertoires play a role in disease outcomes and treatment strategies during viral infections in transplant patients, and in cancer and autoimmune disease therapy. Our data suggests that it is essential that we understand the basic principles of how to drive optimum repertoires for both TCR chains, α and β. We address this important issue by characterizing the CD8 TCR repertoire to a common persistent human viral infection (EBV), which is controlled by appropriate CD8 T cell responses. The ultimate goal would be to determine if the individuals who are infected asymptomatically develop a different TCR repertoire than those that develop the immunopathology of AIM. Here, we begin by doing an in depth characterization of both CD8 T cell TCRα and β repertoires to two immunodominant EBV epitopes over the course of AIM identifying potential factors that may be driving their selection.

scholarly journals Ecto-5′-Nucleotidase (CD73) Regulates the Survival of CD8+ T Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Mariana V. Rosemblatt ◽  
Brian Parra-Tello ◽  
Pedro Briceño ◽  
Elizabeth Rivas-Yáñez ◽  
Suat Tucer ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Interleukin 2 ◽  
Cd8 T Cell ◽  
Antigenic Stimulation ◽  
T Cell Subsets ◽  
Limited Information ◽  
Α Chain ◽  
The Impact

Ecto-5′-nucleotidase (CD73) is an enzyme present on the surface of tumor cells whose primary described function is the production of extracellular adenosine. Due to the immunosuppressive properties of adenosine, CD73 is being investigated as a target for new antitumor therapies. We and others have described that CD73 is present at the surface of different CD8+ T cell subsets. Nonetheless, there is limited information as to whether CD73 affects CD8+ T cell proliferation and survival. In this study, we assessed the impact of CD73 deficiency on CD8+ T cells by analyzing their proliferation and survival in antigenic and homeostatic conditions. Results obtained from adoptive transfer experiments demonstrate a paradoxical role of CD73. On one side, it favors the expression of interleukin-7 receptor α chain on CD8+ T cells and their homeostatic survival; on the other side, it reduces the survival of activated CD8+ T cells under antigenic stimulation. Also, upon in vitro antigenic stimulation, CD73 decreases the expression of interleukin-2 receptor α chain and the anti-apoptotic molecule Bcl-2, findings that may explain the reduced CD8+ T cell survival observed in this condition. These results indicate that CD73 has a dual effect on CD8+ T cells depending on whether they are subject to an antigenic or homeostatic stimulus, and thus, special attention should be given to these aspects when considering CD73 blockade in the design of novel antitumor therapies.

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