Nucleotide Sequencing of Psoriatic Arthritis Tissue before and during Methotrexate Administration Reveals a Complex Inflammatory T Cell Infiltrate with Very Few Clones Exhibiting Features That Suggest They Drive the Inflammatory Process by Recognizing Autoantigens

Abstract

Psoriatic arthritis is an interesting MHC class I allele associated autoimmune disease where injury is likely mediated exclusively by T cells. We used TCR β-chain nucleotide sequencing to gain insight into the adaptive immune events responsible for this injury and determine whether the numerous oligoclonal expansions of this disease represent extreme determinant spreading among driving clones that recognize autoantigen or were non-Ag-driven, inflammation-related expansions. Because methotrexate suppresses but does not eliminate this inflammation, we hypothesized that clones persisting during methotrexate treatment would likely drive the inflammation. Seventy-six percent of the T cell clones in active tissue were polyclonal and unexpanded, accounting for 31% of transcripts. They were decreased greatly by methotrexate. Strikingly, most expanded clones in the inflamed joint did not persist during methotrexate treatment, were found only in inflammatory sites, exhibited no structural homology to one another, and were either CD4 or CD8 in lineage, suggesting they were non-autoantigen-driven, inflammation-related expansions. Only 12% of the expanded clones could be grouped into clonal sets distinguished by structurally homologous CDR3 β-chain amino acid motifs suggesting Ag drive. These were exclusively CD8 in lineage, persisted during methotrexate administration, and were present in both joint fluid and blood implying they were candidate driver clones that recognized an autoantigen. However, a major set of putative driver clones exhibited a previously described EBV-specific β-chain motif, emphasizing that the dominant feature of the disease was activation of multiple clones apparently lacking specificity for an inciting autoantigen.

Improvement of Psoriasis after Tonsillectomy Is Associated with a Decrease in the Frequency of Circulating T Cells That Recognize Streptococcal Determinants and Homologous Skin Determinants

“…Our findings may help to identify some of the autoepitopes that are recognized by T cells in psoriatic lesions. It has been reported by many groups that these lesions are infiltrated by oligoclonal T cells (1), and although most of these clones are transient (1) and probably reflect autoepitope spreading (30), others are dominant and persist or even reappear in lesional skin after treatmentinduced remission (31,32).…”

The Lymphocytic Infiltration in Calcific Aortic Stenosis Predominantly Consists of Clonally Expanded T Cells

“…A histologically normal-appearing valve was obtained during heart transplant for end-stage heart failure secondary to dilated cardiomyopathy. Histologic sectioning and immunochemical staining were performed as described previously (21). The Institutional Review Board of Columbia University approved the study.…”

“…The clonal composition of the T cells infiltrating the stenotic aortic valve was analyzed using RNA extracted from separated PB CD4 and CD8 subpopulations and from the total sample of the aortic valve tissue as described previously (21)(22)(23). Briefly, the valve is minced, transferred to RNAStat-60 reagent, homogenized in a Tissuemizer (IKA Labortechnik), and after centrifugation out of calcific particles, RNA was isolated according to the manufacturer's instructions (Tel-Test).…”

“…cDNA was prepared using oligo(dT) priming. The repertoire composition was first determined in a lower resolution global assessment by ␤-chain CDR3 length distribution or spectratype analysis to characterize the degree of clonal expansions for each of the 23 TCR ␤-chain variable region families (BV or TRBV) in each CAS case, as described previously (21,22). Briefly, primers specific for a particular variable region family (BV) and the constant region (CB) were used in PCR to amplify the TCR ␤-chains in each BV family.…”

The Inflammatory Infiltrate in Calcific Aortic Stenosis is Characterized by Clonal Expansions of T Cells and is Associated with Elevated Proportions of Circulating Activated and Effector Memory CD8 T Cells

“…However, the minor proportion of polyclonal, non-expanded T cells in many CAS samples compared to other inflammatory sites such as atherosclerotic plaques of inflamed synovia (Curran et al 2004, Oksenberg et al 1997, Stemme et al 1991, Swanson et al 1994, argues that inflammation-mediated T cell recruitment is not a general feature of CAS.…”