Regulatory effects of 1alpha,25-dihydroxyvitamin D3 on the cytokine production of human peripheral blood lymphocytes.
We studied the possible regulatory effects of 1alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2D3] on cytokine production and differentiation of subsets of CD4+ [T helper 1 (Th1) and Th2] and CD8+ [T cytotoxic 1 (Tc1) and Tc2] lymphocytes at the single cell level. PBMC from healthy donors were cultured with or without 1alpha,25-(OH)2D3 for up to 21 days. On days 0, 7, 14, and 21, the percentage of cytokine-producing T lymphocytes was analyzed by intracellular cytokine detection with mAb and flow cytometry. Simultaneous staining for cell surface markers allowed discrimination of CD4+ and CD8+ T cell subsets. After culture with 1alpha,25-(OH)2D3 (10(-8) mol/L), no significant effects on the proportion of interferon-gamma (IFNgamma)- or interleukin-4 (IL-4)-producing cells were detected, whereas reduced frequencies of IL-2-producing cells in the CD4+ as well as in the CD8+ population were found. An increase in the low percentage of CD4+ and CD8+ T cells producing the Th2 cytokine IL-13 was noticed. Most interestingly, IL-6-producing CD4+ and CD8+ T cells could only be detected in cultures with 1alpha,25-(OH)2D3, reaching a plateau after 14 days. The percentage of IL-6-producing T cells induced by 1alpha,25-(OH)2D3 after a given time period remained stable for at least 7 weeks. Studies of cytokine coexpression revealed that about 70% of IL-6-producing CD4+ and CD8+ cells were also positive for IL-2, but more than 90% were negative for IFNgamma, IL-4, or IL-13, respectively. This suggests that the IL-6-producing population does not match the Th1/Tc1-like (IFNgamma+) or Th2/Tc2-like (IL-4+ or IL-13+) subset. The influence of 1alpha,25-(OH)2D3 on cytokine production by lymphocytes is probably an important point of intersection between the endocrine and the immune system.
Willheim
M
M
Institute of General and Experimental Pathology, Clinic of Internal Medicine IV, University of Vienna, Austria. martin.willheim@akh-wien.ac.at
Thien
R
R
Schrattbauer
K
K
Bajna
E
E
Holub
M
M
Gruber
R
R
Baier
K
K
Pietschmann
P
P
Reinisch
W
W
Scheiner
O
O
Peterlik
M
M
D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology*; D016207:Cytokines / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D007378:Interleukins / Q000096:biosynthesis; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism
D016207:Cytokines; D015850:Interleukin-6; D007378:Interleukins; D007371:Interferon-gamma; D002117:Calcitriol