Direct Recognition of Foreign MHC Determinants by Naive T Cells Mobilizes Specific Vβ Families Without Skewing of the Complementarity-Determining Region 3 Length Distribution

Abstract

The capacity of T cells to interact with nonself-APC, also referred to as direct allorecognition, is an essential feature of the cellular response involved in graft rejection. However, there is no study on TCR repertoire biases associated with direct restricted T cell activation. In this paper, we have addressed the impact of direct recognition on the whole naive T cell repertoire, using a new approach that provides, for the first time, an integrated depiction of the quantitative and qualitative alterations in the TCR Vβ transcriptome. This method can differentiate resting patterns from polyclonally activated ones, as evidenced by superantigen usage. According to this new readout, we show that direct recognition of nonself-MHC molecules triggers mRNA accumulation of several TCR Vβ families, specific to the combination studied. Moreover, in marked contrast to the situation that prevails in indirect allorecognition, T cell activation through the direct presentation pathway was not associated with skewing of the complementarity determining region (CDR) 3 length distribution. Altogether, these data argue for the significance of TCR contacts with the MHC framework in direct allorecognition. In addition, the TCR diversity mobilized by this interaction and the massive TCRβ mRNA accumulation observed after a few days of culture suggest that a significant proportion of naive T cells receive a signal leading to TCRβ transcriptional activation even though only a few of them engage in mitosis.

Expansion of Highly Differentiated Cytotoxic Terminally Differentiated Effector Memory CD8+ T Cells in a Subset of Clinically Stable Kidney Transplant Recipients

“…[35][36][37] A capillary sequencer (Applied Biosystems 3730) 38 was used to determine the CDR3 length distribution after amplification of the Vb genes transcript. 39 The level of Vb family transcripts was measured by quantitative RT-PCR and normalized by a reference gene (HPRT).…”

Different Qualitative and Quantitative Regulation of Vβ TCR Transcripts During Early Acute Allograft Rejection and Tolerance Induction

“…Moreover, the cross-reactive nature of the TCR makes difficult to define a clear structure-function relationship at the TCR level (8). Thus, our understanding of the relevance of TCR alterations should be enhanced by knowledge of the amounts of mRNA involved in these repertoire biases (9,10). Moreover, in allorecognition the situation is further complicated by superimposing recognition of allogeneic MHC expressed by foreign APC, referred to as direct recognition (11), upon the selfrestricted recognition of allogeneic peptides presented by recipient APCs, referred to as indirect recognition (12).…”

“…In this paper, for the first time, we use a new global approach, referred to as TcLandscape (9,10), to study in vivo T cell mobilization by an allograft through analysis of V␤ mRNA transcription. Qualitative alterations of V␤ use are correlated with the magnitude of accumulation of each V␤ mRNA species involved in a T cell response and can be represented as a V␤ transcriptome "landscape" for each informative time point of a T cell immune response (9,10).…”

“…Qualitative alterations of V␤ use are correlated with the magnitude of accumulation of each V␤ mRNA species involved in a T cell response and can be represented as a V␤ transcriptome "landscape" for each informative time point of a T cell immune response (9,10). Using this approach, we revisited the complex in vivo T cell response during acute rejection of heart allografts placed in unmodified recipients and during induction of tolerance by donor-specific blood transfusion (DST) in the same combination (15).…”

Development of CD25– regulatory T cells following heart transplantation: Evidence for transfer of long‐term survival

“…Total RNA was isolated using RNeasy Mini Kit (Qiagen, Courtaboeuf, France). RNA (2 lg) was reverse transcribed as described [58]. A constant amount of cDNA was amplified in 25 lL SYBR Green PCR Core Reagent (Applied Biosystems, Foster City, CA) with 1 mg/mL BSA, 3 mM MgCl 2 , 200 lM of each dNTP, 0.6 U AmpliTaq Gold polymerase, and 300 nM of each primer in 1 Â SYBR Green PCR buffer.…”