In vivo T-cell clonal amplification at time of acute graft-versus-host disease

Abstract

In a series of patients transplanted with HLA-matched allogeneic bone marrow grafts (alloBMT), we previously showed that a few T-cell receptor (TCR) V alpha and V beta gene segment transcripts were overexpressed in skin compared with blood at the time of acute graft- versus-host disease (aGVHD). Here, in one selected patient with overexpressed V beta 16 and V alpha 11 transcripts in skin, we analyzed the junctional variability of these transcripts in donor blood, patient blood, and skin collected at aGVHD onset. A unique junctional region sequence accounted for 81% of in frame V beta 16 transcripts (13 of 16) in skin and 59% (13 of 22) in patient blood. Similarly, two recurrent junctional region sequences were found in skin V alpha 11 transcripts, one accounting for 66% (21 of 32) and the other for 16% (5 of 32). These recurrences were also found in patient blood (36% and 15% of V alpha 11 transcripts, respectively). To extend our analysis, a polymerase chain reaction (PCR)-based method was used to precisely determine TCR beta transcript length in run-off reactions using uncloned bulk cDNA samples. All V beta-C beta PCR products analyzed in donor blood, as well as the majority of those analyzed in patient blood, included transcripts with highly diverse junctional region sizes. As expected from the sequence data, most V beta 16-C beta PCR products in skin and patient blood were of the same size (ie, same junctional region). In addition, V beta 3, V beta 5, and V beta 17 transcripts in skin were shown to display highly restricted size variability. The clonality of the V beta 16-C beta and V beta 17-C beta transcripts was further supported by the results of run-off reactions using 13 J beta specific primers. We have identified several recurrent TCR transcripts in skin, some of them also present in patient blood. These data support the view that several T-cell subpopulations are clonally expanded in vivo at the time of aGVHD onset in this case of related HLA-matched alloBMT.

Myelodysplasia‐associated autoimmunity: clinical and pathophysiologic concepts

“…Persisting clonal expansions are not necessarily an expression of a malignant process; they also represent clonal or oligoclonal expansion of possibly autoreactive T cells and are most marked in CD8+ populations. The increase of CD57 expression by the CD8+ cells, as well as the demonstration of expanded TCR VB families expressing CD57, are characteristic features of diseases attributable to an activated immune environment such as acute graft vs. host disease, multiple sclerosis and rheumatoid arthritis [61–63]. In these well‐established autoimmune disorders clonally expanded T cells bearing similar VB subfamilies proliferate dominantly in different patients, reflecting a specific response of auto‐reactive T cells to certain antigens.…”

“…Hypothetical models propose immune triggering of the effectors’ lymphocytes, either by aberrantly expressed oncogenes and fusion genes in the haematopoietic progenitor cells or by super‐antigens derived from bacteria or viruses [52,64]. Such effector cells should have limited TCR usage among different MDS patients, reflecting the common pathogenic, antigen‐driven oligoclonal expansion [61–63].…”

Application of the Molecular Analysis of the T-Cell Receptor Repertoire in the Study of Immune-Mediated Hematologic Diseases

“…Analysis of the TCR has been employed in the study of classical autoimmune diseases [9][10][11][12][13][14][15][16][17], and T-cell lymphoproliferative disorders [18][19][20][21]. During the acute stage of infectious or autoimmune diseases, antigen-drive expansion will lead to over-representation of immunodominant T-cell clones reflected in VB and CDR3 skewing.…”

“…Skewing of the T-cell VB spectrum has also been described for many animal models of autoimmune diseases, such as encephalitis [10,23] and thyroiditis [11]. In humans, expansion of specific CDR3 VB TCR clones has been found in multiple sclerosis [12], type I diabetes mellitus [13], rheumatoid arthritis [14,15,24], primary biliary cirrhosis [16], psoriasis [17,25], and during graft-versus-host disease (GvHD) [4,9,[26][27][28][29]. Powerful pathologic effects of the immune system observed in autoimmune diseases, such as aplastic anemia (AA) demonstrate the potential for immunebased cellular therapies and vaccinations in the treatment of malignant disorders, including leukemia.…”

Development of improved T cell receptor beta variable gene identification technology and its application post hematopoietic stem cell transplantation

“…On the other hand, while bone marrow harvests require no mobilization therapies and can often be done in a single one-day collection, the pain associated with bone marrow harvests may take 2 to 4 weeks to subside 17,18 . In addition, various studies have reported a decreased time for reconstitution of the immune system, less transplant-related toxicities and mortalities, and a decreased rate of GVHD occurrence in peripheral blood stem cell recipients compared to bone marrow recipients [19][20][21][22][23] .…”