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Increased polyamines may downregulate interleukin 2 production in rheumatoid arthritis
E Flescher1, T L Bowlin, A Ballester
1Clinical Immunology Section, Audie L. Murphy Memorial Veterans Hospital, San Antonio, Texas.
The Journal of Clinical Investigation
|April 1, 1989
Summary
Excessive polyamines impair immune function by reducing Interleukin-2 (IL-2) production in rheumatoid arthritis (RA). Inhibiting polyamine synthesis or oxidation boosts IL-2 levels in RA patients.
Area of Science:
- Immunology
- Biochemistry
Background:
- Rheumatoid arthritis (RA) is linked to reduced Interleukin-2 (IL-2) production, a key cytokine for immune responses.
- Polyamines are known to downregulate immune reactivity, but their specific role in RA pathogenesis is unclear.
Purpose of the Study:
- To investigate the contribution of excessive polyamines to IL-2 deficiency in rheumatoid arthritis.
- To explore the impact of modulating polyamine metabolism on IL-2 production in RA.
Main Methods:
- Assessed IL-2 production by peripheral blood mononuclear cells (PBMC) from RA patients and healthy controls.
- Utilized ornithine decarboxylase inhibitors, polyamine oxidase (PAO) inhibitors, and catalase to modulate polyamine levels.
- Investigated the role of monocytes in the observed effects.
Main Results:
- RA PBMC exhibited significantly higher polyamine concentrations (2-20 fold) compared to normal PBMC.
- Inhibiting polyamine production or oxidation increased IL-2 production by RA PBMC.
- The effect of PAO inhibition on IL-2 production was found to be monocyte-mediated.
- Exogenous spermidine suppressed the increase in IL-2 production in the presence of monocytes.
Conclusions:
- Excessive polyamines and their oxidation products contribute to IL-2 deficiency in RA.
- Modulating polyamine metabolism, particularly through monocyte-dependent mechanisms, can restore IL-2 production.
- These findings suggest polyamines play a role in the decreased T cell effector function observed in RA.
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