Suppression of autologous mixed leukocyte reaction in type 1 diabetes mellitus by in vivo-activated T lymphocytes.
In vivo-activated interleukin 2 receptor-positive T lymphocytes (Tac cells) are demonstrable and the autologous mixed leukocyte reaction (AMLR) is impaired in several autoimmune diseases, including type 1 insulin-dependent diabetes mellitus (IDDM). We investigated AMLR in greater detail, together with possible relationships between AMLR and Tac lymphocytes in IDDM. Coculture experiments with HLA identical patient-healthy sibling pairs revealed that both responder and stimulator cells of diabetic patients function abnormally in AMLR. Suppressive Tac lymphocytes among responder T cells seemed to impair their proliferation. The removal of Tac cells by immunomagnetic beads led to a striking enhancement of proliferation, while the restoration of AMLR cultures with enriched Tac cells was accompanied by a diminished response. The reasons for the poor stimulatory capacity of patient cells are at present unknown but may be due to altered function and/or structure of HLA-DR molecules.
Räsänen
L
L
Department of Biomedical Sciences, University of Tampere, Finland.
Hyöty
H
H
Lehto
M
M
Kallioniemi
O P
OP
Huupponen
T
T
Tuomilehto-Wolf
E
E
Kaprio
E
E
Leinikki
P
P
D002478:Cells, Cultured; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology*; D005190:Family; D006680:HLA Antigens / Q000032:analysis / Q000235:genetics; D006239:Haplotypes; D006801:Humans; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D015375:Receptors, Interleukin-2 / Q000032:analysis; D012016:Reference Values; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
D006680:HLA Antigens; D015375:Receptors, Interleukin-2