title: Oligoclonal and polyclonal CD4 and CD8 lymphocytes in aplastic anemia and paroxysmal nocturnal hemoglobinuria measured by V beta CDR3 spectratyping and flow cytometry.
abstract: We have hypothesized that in aplastic anemia (AA) the presence of antigen-specific T cells is reflected by their contribution to the expansion of a particular variable beta chain (V beta) subfamily and also by clonal CDR3 skewing. To determine the role of disease-specific "signature" T-cell clones in AA, we studied preferential V beta usage by flow cytometry and analyzed V beta-CDR3 regions for the presence of oligoclonality. We first established the contribution of each V beta family to the total CD4(+) and CD8(+) lymphocyte pool; in AA and paroxysmal nocturnal hemoglobinuria, a seemingly random overrepresentation of different V beta families was observed. On average, we found expansion in 3 (of 22 examined) V beta families per patient. When the contribution of individual V beta families to the effector pool was examined, more striking V beta skewing was found. V beta-CDR3 size distribution was analyzed for the expanded V beta families in isolated CD4(+) and CD8(+) populations; underrepresented V beta families displayed more pronounced CDR3 skewing. Expanded CD4(+)V beta subfamilies showed mostly a polyclonal CDR3 size distribution with only 38% of skewing in expanded V beta families. In contrast, within overrepresented CD8(+)V beta types, marked CDR3 skewing (82%) was seen, consistent with nonrandom expansion of specific CD8(+) T-cell clones. No preferential expansion of particular V beta families was observed, in relation to HLA-type. In patients examined after immunosuppressive therapy, an abnormal V beta-distribution pattern was retained, but the degree of expansion of individual V beta was lower. As V beta skewing may correlate with relative V beta size, oligoclonality in combination with numerical V beta expansion can be applied to recognition of disease-specific T-cell receptors.
authors.affiliation: Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Risitano
authors.forename: Hoon
authors.initials: H
authors.lastname: Kook
authors.forename: Weihua
authors.initials: W
authors.lastname: Zeng
authors.forename: Guibin
authors.initials: G
authors.lastname: Chen
authors.forename: Neal S
authors.initials: NS
authors.lastname: Young
authors.forename: Jaroslaw P
authors.initials: JP
authors.lastname: Maciejewski
mesh_terms: D000741:Anemia, Aplastic / Q000276:immunology* / Q000473:pathology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D002999:Clone Cells / Q000276:immunology / Q000473:pathology; D022801:Complementarity Determining Regions / Q000032:analysis; D005434:Flow Cytometry; D006457:Hemoglobinuria, Paroxysmal / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis
chemical_list: D022801:Complementarity Determining Regions; D007166:Immunosuppressive Agents; D016693:Receptors, Antigen, T-Cell, alpha-beta