A study of cytokine protein secretion, frequencies of cytokine expressing cells and IFN-G gene polymorphisms in normal individuals.
BACKGROUND
Cytokines are major regulators of immune responses, and there is evidence that they play a role in allograft rejection. Before embarking on a detailed study of pretransplant cytokine profiles in renal allograft recipients, we wished to investigate variations in cytokine protein secretion, numbers of cytokine expressing T cells, and cytokine gene polymorphisms in normal volunteers.


METHODS
Twenty normal healthy volunteers were studied. Cytokine protein secretion [interleukin- (IL) 2, IL-4, IL-10, and interferon- (IFN) y] and numbers of cytokine expressing CD3+ T cells (IL-2, IL-4, IL-10, and IFN-gamma) were quantified by means of enzyme-linked immunosorbent assay and two-color flow cytometry respectively. IFN-gamma gene polymorphisms were determined by polymerase chain reaction and autoradio graphy.


RESULTS
Large interindividual variations in both the quantity of IL-2, IL-4, IL-10, and IFN-gamma cytokine protein secreted and numbers of IL-2 and IFN-gamma expressing T cells were demonstrated. However, numbers of IL-4 and IL-10 expressing cells were found to be below detectable limits by flow cytometry. In the case of IFN-gamma, a bi-modal distribution was seen for the quantity of protein secreted. In addition, correlations were observed between IL-2 protein and frequency of IL-2 expressing T cells. However, no relationship was found between IFN-gamma protein levels, numbers of IFN-gamma expressing cells and IFN-gamma gene polymorphisms.


CONCLUSIONS
We have demonstrated large differences in both numbers of T helper 1 cytokine expressing cells and the quantity of T helper 1 and T helper 2 cytokine protein secreted between normal individuals. Although the amount of IL-2 protein secreted appeared to be determined by the frequency of IL-2 expressing cells, this was not the case for IFN-gamma.
Cartwright
N
N
Department of Immunology, Combined Laboratories, Derriford Hospital, Plymouth, UK.
Demaine
A
A
Jahromi
M
M
Sanders
H
H
Kaminski
E R
ER
D000328:Adult; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000097:blood*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics*; D007378:Interleukins / Q000096:biosynthesis / Q000097:blood; D008297:Male; D011110:Polymorphism, Genetic; D012016:Reference Values; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D016207:Cytokines; D007378:Interleukins; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate