Interferon-gamma release in sympathetically denervated rat submaxillary lymph nodes.

OBJECTIVE

To examine the regulation of interferon (IFN)-gamma release by cells derived from submaxillary lymph nodes of rats subjected to an acute or chronic superior cervical ganglionectomy (SCGx).

METHODS

A unilateral SCGx and a contralateral sham operation were performed. Twenty hours or 7 days later cells from submaxillary lymph nodes were incubated for 24 h without any additional treatment (experiment 1), after adding lipopolysaccharide or concanavalin A (experiment 2) or after adding norepinephrine (NE, 10(-8) M; experiment 3). IFN-gamma concentration in the culture media was measured by ELISA.

RESULTS

Compared to controls, cells obtained from lymph nodes at a time of degeneration of sympathetic nerve terminals released more IFN-gamma, whereas those derived from chronically SCGx lymph nodes released less IFN-gamma. Stimulation of IFN-gamma release by mitogens was detectable in the innervated or acutely denervated lymph nodes, but not in chronically denervated lymph nodes. When the effect of 10(-8) M NE on IFN-gamma release was tested, the neurotransmitter augmented cytokine release in cells prepared from chronically denervated lymph nodes only.

CONCLUSION

The microenvironment provided by local sympathetic nerves is essential to enable an appropriate IFN-gamma release by submaxillary lymph node cells to occur.