TCR Expression and Clonality Analysis in Peripheral Blood and Lymph Nodes of HIV-Infected Patients

Abstract

ABSTRACT: We compared the T cell receptor (TCR) Vβ gene family repertoire in peripheral blood mononuclear cells (PBMC) and lymph node (LN) cells from 7 human immunodeficiency virus (HIV)-infected patients and 3 seronegative healthy controls. Virtually all the Vβ family specificities were represented in patient PBMC and LN cells, and mean values for each specificity were comparable to figures in seronegative controls. In 4 patients, however, some Vβ gene segment transcripts were overrepresented in the LN compartment, compared to the peripheral blood counterpart. To ascertain whether this phenomenon was due to polyclonal or oligoclonal expansion of T cells bearing the relevant Vβ gene product, we sequenced the entire CDR3 region of a panel of 238 PCR clones corresponding to the Vβ transcripts expanded in LN; as control, the same regions were cloned and sequenced in patient’s PBMC, and in PBMC and LN cells from seronegative individuals. This analysis disclosed preferential usage of Jβ2 genes in PBMC and LN cells from both seropositive patients and controls, regardless of the Vβ gene segment considered, thus indicating that this skewness in the Vβ-Jβ repertoire could be a consistent feature of at least a part of the Vβ repertoire in different lymphoid compartments, regardless of the pathologic conditions. In addition, in LN from HIV seropositive patients we found the presence of recurrent TCR rearrangements, accounting for 8–23% of the generated clones, in each of the 4 Vβ specificities analyzed; recurrent sequences were not found in PBMC from patients nor in PBMC and LN cells from seronegative controls. These findings suggest that antigen-driven oligoclonal T cell expansions may occur in vivo in lymphoid organs of HIV seropositive patients.