Interaction between interleukin 10 and interleukin 6 in human B-cell differentiation.
Contrary to their opposing action on human T-lymphocytes and monocytes, both Interleukin (IL-)10 and IL-6 are potent differentiation factors of human B-cells. Both are known to induce immunoglobulin (Ig) production. The precise mechanism of this converging effect of IL-6 and IL-10 remains elusive, however. Here we investigated the role of IL-6 in the IL-10 dependent B-cell differentiation into Ig secreting cells. We found that co-stimulation of SAC-stimulated human peripheral B-lymphocytes with IL-10 and IL-6 exhibited no additive effect on Ig production over stimulation with IL-10 alone, and that IL-6 receptor blockade only mildly inhibited IL-10 induced Ig synthesis. In fact, we could show that stimulation of B-cells with IL-10 somewhat suppressed SAC induced autocrine IL-6 production. Despite this suppression IL-6 levels remained sufficiently high to stimulate its receptor, and IL-6 binding to the B-cell surface was not affected. The failure of IL-6 to exert an additional effect on SAC+IL-10 induced Ig production suggests that IL-10 may recruit components of the IL-6 intracellular pathway for Ig induction. In conclusion we could demonstrate that IL-10 acts on B-cell differentiation independently of autocrine IL-6 and that it had a considerably mild effect on B lymphocytic autocrine IL-6 secretion. This still allows an IL-6 effect in the presence of IL-10 which appears adaptive with a view to the converging effects of these two cytokines on human B lymphocytes. Our study thus adds to the appreciation of the complex cytokine regulation of the immune system.
Bönig
H
H
Department of Pediatric Hematology and Oncology, Heinrich-Heine-University Medical Center Düsseldorf.
Packeisen
J
J
Röhne
B
B
Hempel
L
L
Hannen
M
M
Klein-Vehne
A
A
Burdach
S
S
Körholz
D
D
D000906:Antibodies / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation; D002469:Cell Separation; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D016753:Interleukin-10 / Q000494:pharmacology / Q000502:physiology*; D015850:Interleukin-6 / Q000494:pharmacology / Q000502:physiology*; D008213:Lymphocyte Activation; D019947:Receptors, Interleukin-6 / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction
D000906:Antibodies; D007136:Immunoglobulins; D015850:Interleukin-6; D019947:Receptors, Interleukin-6; C113250:interleukin-6 receptor alpha; D016753:Interleukin-10