Changing Patterns of Dominant TCR Usage with Maturation of an EBV-Specific Cytotoxic T Cell Response

Abstract

Infection with EBV provides a unique opportunity to follow the human CD8+ T cell response to a persistent, genetically stable agent from the primary phase, as seen in infectious mononucleosis (IM) patients, into long-term memory. This study focuses on the response to an immunodominant HLA-A2.01-restricted epitope, GLCTLVAML, from the EBV-lytic cycle Ag BMLF1. TCR analysis of the highly amplified primary response to this epitope revealed markedly oligoclonal receptor usage among in vitro-derived clones, with similar clonotypes dominant in all three IM patients studied. Direct staining of IM T cell preparations with the A2.01/GLCTLVAML tetramer linked this oligoclonal epitope-specific response with appropriate Vβ subset expansions in the patients’ blood. These patients were studied again >2 years later, at which time TCR analysis of in vitro-reactivated clones suggested that rare clonotypes within the primary response had now come to dominate memory. Five additional A2.01-positive IM patients were studied prospectively for Vβ subset representation within primary and memory epitope-specific populations as identified by tetramer staining. In each case, the primary response contained large Vβ2, Vβ16, or Vβ22 components, and in three of five cases the originally dominant Vβ was represented very poorly, if at all, in memory. We conclude 1) that an EBV epitope-specific primary response large enough to account for up to 10% CD8+ T cells in IM blood may nevertheless be dominated by just a few highly expanded clonotypes, and 2) that with persistent viral challenge such dominant T cell clonotypes may be lost and replaced by others in memory.

In Vivo Persistence of Codominant Human CD8+ T Cell Clonotypes Is Not Limited by Replicative Senescence or Functional Alteration

“…In contrast, a small but yet detectable proportion (Х7%) of the effector memory compartment contained CD28 ϩ cells (designed as EM28 ϩ ). In several viral systems, responses to a given T cell-defined Ag often showed strong TCR selection resulting in highly restricted TCR usage (7)(8)(9)(10)(11)(12)32). Our finding that the robust NY-ESO-1-specific T cell response is characterized by increased frequencies and differentiation into EM28…”

“…In humans, highly restricted TCR usage has been described in several viral systems, including influenza (5,6), EBV (7,8), CMV (9), and HIV-1 (10 -12). Thus, the limited TCR diversity seems to be a conserved feature of CD8 ϩ T cell responses to viral infection.…”

Intrathecal immune responses to EBV in early MS

“…In a subset of study patients, CD8 1 T cells from the blood and the CSF were tested for EBV specificity by staining them at 41C for 30 min with the HLA-A Ã 0201/BMLF-1 GLCTLVAML or the B Ã 0702/ EBNA-3A RPPIFIRRL tetramer (Beckman Coulter); BMLF-1 is a protein that is part of the lytic cycle of EBV, while EBNA-3A is a latent protein of EBV [43]. Both of these peptides were encompassed in our EBV peptide pool.…”

EBV-Specific CD8+ T Cell Memory: Relationships Between Epitope Specificity, Cell Phenotype, and Immediate Effector Function

“…There the expansion of lytic epitope responses is at least 10-fold greater than that of latent responses (3), and this is even true for the primary response to a lytic cycle epitope such as YVL, of which the subsequent representation in memory can be quite low (N. Annels and A. Hislop, manuscript in preparation). Indeed, some clonotypes within the highly amplified primary response to the lytic cycle epitope GLC can apparently be driven to the point of clonal exhaustion (29), whereas immunodominant clonotypes within the less highly amplified response to the latent epitope FLR are not (38,39). These differences in the degree to which responses are amplified may reflect the higher levels of Ag load produced by lytic EBV replication in vivo compared with that present in latently infected cells.…”

“…These stained cells then were analyzed on an Epics flow cytometer (Beckman Coulter). Note that color compensation between the different fluorochromes was set with single fluorochrome-stained cells from the same test population as described previously (29).…”