Defective CD2 pathway T cell activation in systemic lupus erythematosus.
CD2 (T11; sheep erythrocyte receptor) is the surface component of an alternative, antigen-independent pathway of human T cell activation. The response to certain anti-CD2 antibodies is relatively independent of accessory cell signals and therefore provides a direct measurement of T cell function. The CD2 pathway may be important in the differentiation of thymocytes, on which the expression of CD2 precedes the appearance of the CD3-T cell receptor complex. In view of the impaired T cell regulation of immune responses in patients with systemic lupus erythematosus (SLE), we examined the activation of peripheral blood lymphocytes by anti-CD2 antibodies in 57 SLE patients and 32 normal control subjects. The CD2 pathway response was lower in the SLE patients (P less than 0.0001); 18 of the 57 SLE patients had a lower response than any of the control subjects. The SLE low-responder patients did not differ from the normal-responder patients in terms of disease activity or use of antiinflammatory and immunosuppressive medications. Low responses to anti-CD2 were corrected to normal by the coaddition of a submitogenic amount of phorbol myristate acetate (1 ng/ml). In some low-responder patients, the responses were normalized by the removal of non-T cells. The data indicate that some SLE patients have impaired responses to CD2 pathway activation and that this may reflect intrinsic T cell defects and/or regulatory influences of non-T cells.
Fox
D A
DA
Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor.
Millard
J A
JA
Treisman
J
J
Zeldes
W
W
Bergman
A
A
Depper
J
J
Dunne
R
R
McCune
W J
WJ
D000328:Adult; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D000954:Antigens, Surface / Q000502:physiology; D018801:CD2 Antigens; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000378:metabolism / Q000503:physiopathology*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D011971:Receptors, Immunologic / Q000502:physiology*; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D012016:Reference Values; D013601:T-Lymphocytes / Q000378:metabolism / Q000502:physiology*
D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D018801:CD2 Antigens; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2