T cell receptor repertoire of CD4+ and CD8+ T cell subsets in the allogeneic bone marrow transplant recipient

Early recovery of CD4 T cell receptor diversity after "lymphoablative" conditioning and autologous CD34 cell transplantation

T cell diversity posttransplantation is thought to be severely restricted, based on T cell receptor beta-chain immunophenotyping or spectratyping. Using beta-chain sequencing, we studied CD4 T cell diversity in 2 adult patients undergoing "lymphoablative" conditioning with cyclophosphamide (Cy), total body irradiation (TBI), and antithymocyte globulin (ATG) and autologous transplantation of hematopoietic cells depleted of T cells by enrichment for CD34 cells. The indication for the transplantation was systemic sclerosis (SSc) or multiple sclerosis (MS). Pretransplantation, the estimated number of distinct beta chains (the minimum number of CD4 T cell clones) in the 2 patients was 600,000 to 700,000, similar to the number in a healthy control. This number was 200,000 to 500,000 at 1 month posttransplantation and 400,000 to 1,600,000 at 12 months posttransplantation. In conclusion, the number of T cells early after lymphoablative conditioning and autologous CD34 cell transplantation may be more diverse than previously appreciated, possibly because many T cell clones survive the conditioning or are reinfused with the graft. Thus, the therapy may not be completely T cell lymphoablative.

Proteomic analyser with applications to diagnostics and vaccines

This paper describes a method for proteomic analysis with applications to diagnostics and vaccines. A panel of N (> or = 1) reagents called X(j), with j = 1 to N, is used. The binding strength of each of the X(j) reagents to each other is measured, for example by an ELISA assay, giving an N x N matrix K. The matrix K is used to define another set of N reagents called Y(j), with j = 1 to N, each of which is a linear combination of the X(j) reagents and each of which is tailored to be complementary to one of the X(j) reagents. Each of the N pairs of reagents X(j) and Y(j) defines an axis in an N-dimensional shape space. The definition of these axes facilitates proteomic analysis of diverse biological samples, for example, mixtures of proteins such as serum samples or T cell extracts. A method for defining and measuring similarity between pairs of biological samples and between sets of biological samples in the context of the set of N reagent pairs is described. This leads to methods for using the N reagent pairs in the diagnosis of diseases and in the formulation of preventive and therapeutic vaccines. The relationship of this work to previous research on shape space is discussed.

Ex vivo-expanded hematopoietic cell graft recipients exhibit T cell repertoire diversity similar to that seen after conventional stem cell transplants

The feasibility of using ex vivo-expanded hematopoietic progenitor cells to reconstitute hematopoiesis after high-dose chemotherapy is presently being examined. Early studies have shown that myeloid and erythroid hematopoiesis can be successfully reconstituted after high-dose chemotherapy and ex vivo-expanded hematopoietic cell transplantation. The lymphoid reconstitution, however, has not been addressed previously. In this study, we examined the diversity of the T cell receptor V beta chain (TCRBV) repertoires in 5 breast cancer patients who were transplanted with ex vivo-expanded bone marrow mononuclear cells as the only source of hematopoietic graft. Using the TCRBV third complementarity determining region (CDR3) fingerprinting methodology, it is shown that CD4(+) and CD8(+) T cell subsets after ex vivo-expanded hematopoietic cell graft transplants exhibit TCRBV diversities that are similar in complexity when compared to those seen after conventional autologous peripheral blood stem cell transplants (PBSCT). No apparent difference in the extent of CDR3 diversity was found between ex vivo expanded and conventional autologous PBSCT recipients when the CD4(+) and CD8(+) subsets were further separated into CD45RA(+) "naïve" and CD45RO(+) "memory" subsets. The diversity of the CD45RA(+) naïve subsets was as complex as that of the CD45RO(+) memory subsets. These results indicate that T cell repertoire diversification is not further compromised when ex vivo-expanded hematopoietic cells are used instead of autologous peripheral blood stem cells as the only source of graft.