Fyn and CD70 expression in CD4+ T cells from patients with systemic lupus erythematosus.
OBJECTIVE
CD4+ T cells from patients with systemic lupus erythematosus (SLE) display defective function that contributes to abnormal activation of B cells and autoantibody production.


METHODS
We compared the transcript and protein levels of Fyn and CD70 in CD4+ T cells from patients with SLE (n = 41) and healthy individuals (n = 34). The CD4+ T cells were isolated by positive biomagnetic separation technique. The quantitative analysis of messenger RNA was performed by reverse transcription and real-time quantitative PCR. The protein contents in the CD4+ T cells were determined by Western blotting analysis.


RESULTS
We observed significantly higher levels of Fyn (p = 0.03) and CD70 (p = 0.029) transcripts in SLE CD4+ T cells than in controls. There was a significant increase in CD70 protein levels (p < 0.0001), but not Fyn protein levels (p = 0.081) in CD4+ T cells from patients with SLE compared to healthy individuals. In the group with high disease activity [SLE Disease Activity Index (SLEDAI) >/= 9], we observed a significantly higher Fyn protein content than in controls (p = 0.030). There was no correlation between Fyn and CD70 protein levels in SLE CD4+ T cells and disease activity as expressed in the SLEDAI scale.


CONCLUSIONS
We confirmed previous observations of higher expression of CD70 in CD4+ T cells from patients with SLE. Our findings suggest that increased Fyn protein content in CD4+ T cells can be associated with high SLE disease activity.
Kozlowska
Anna
A
Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, Poznan, Poland.
Hrycaj
Pawel
P
Lacki
Jan K
JK
Jagodzinski
Pawel P
PP
D000328:Adult; D000818:Animals; D053282:CD27 Ligand / Q000235:genetics / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000502:physiology*; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation; D008180:Lupus Erythematosus, Systemic / Q000276:immunology / Q000503:physiopathology*; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D051379:Mice; D008875:Middle Aged; D051076:Proto-Oncogene Proteins c-fyn / Q000235:genetics / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000276:immunology
D053282:CD27 Ligand; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; C494957:FYN protein, human; D051076:Proto-Oncogene Proteins c-fyn