title: Alloreactive CD154-expressing T-cell subsets with differential sensitivity to the immunosuppressant, belatacept: potential targets of novel belatacept-based regimens.
abstract: Belatacept blocks CD28-mediated T-cell costimulation and prevents renal transplant rejection. Understanding T-cell subset sensitivity to belatacept may identify cellular markers for immunosuppression failure to better guide treatment selection. Here, we evaluate the belatacept sensitivity of allo-antigen-specific CD154-expressing-T-cells, whose T-cytotoxic memory (TcM) subset predicts rejection with high sensitivity after non-renal transplantation. The belatacept concentration associated with half-maximal reduction (EC50) of CD154 expression was calculated for 36 T-cell subsets defined by combinations of T-helper (Th), Tc, T-memory and CD28 receptors, following allostimulation of peripheral blood leukocytes from 20 normal healthy subjects. Subsets were ranked by median EC50, and by whether subset EC50 was correlated with and therefore could be represented by the frequency of other subsets. No single subset frequency emerged as the significant correlate of EC50 for a given subset. Most (n = 25) T-cell subsets were sensitive to belatacept. Less sensitive subsets demonstrated a memory phenotype and absence of CD28 receptor. Potential drug-resistance markers for future validation include the low frequency highly differentiated, Th-memory-CD28-negative T-cells with the highest median EC50, and the least differentiated, high-frequency Tc subset, with the most CD28-negative T-cells, the third highest median EC50, and significant correlations with frequencies of the highest number of CD28-negative and memory subsets.
authors.affiliation: Plexision, Inc., 4424 Penn Avenue, #202, Pittsburgh, PA 15224 USA.|Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, 4401 Penn Avenue, Pittsburgh, PA 15224. USA.
authors.forename: Chethan
authors.initials: C
authors.lastname: Ashokkumar
authors.affiliation: Bristol-Myers-Squibb, PO Box 4000, Princeton, NJ 08543-4000 USA.
authors.forename: Bishu
authors.initials: B
authors.lastname: Ganguly
authors.affiliation: Bristol-Myers-Squibb, PO Box 4000, Princeton, NJ 08543-4000 USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Townsend
authors.affiliation: Plexision, Inc., 4424 Penn Avenue, #202, Pittsburgh, PA 15224 USA.
authors.forename: Jaimie
authors.initials: J
authors.lastname: White
authors.affiliation: Plexision, Inc., 4424 Penn Avenue, #202, Pittsburgh, PA 15224 USA.
authors.forename: Samantha
authors.initials: S
authors.lastname: Levy
authors.affiliation: Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, 4401 Penn Avenue, Pittsburgh, PA 15224. USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Moritz
authors.affiliation: Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, 4401 Penn Avenue, Pittsburgh, PA 15224. USA.
authors.forename: George
authors.initials: G
authors.lastname: Mazariegos
authors.affiliation: Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, 4401 Penn Avenue, Pittsburgh, PA 15224. USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, 4401 Penn Avenue, Pittsburgh, PA 15224. USA.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Sindhi
mesh_terms: D000069594:Abatacept / Q000494:pharmacology* / Q000627:therapeutic use; D018106:CD28 Antigens / Q000378:metabolism; D023201:CD40 Ligand / Q000378:metabolism*; D016000:Cluster Analysis; D006084:Graft Rejection / Q000517:prevention & control; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016030:Kidney Transplantation; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism
chemical_list: D018106:CD28 Antigens; D007166:Immunosuppressive Agents; D023201:CD40 Ligand; D000069594:Abatacept