Autonomic nervous system regulation of murine immune responses as assessed by local surgical sympathetic and parasympathetic denervation

Abstract

The effect of local sympathetic denervation on immune responses of submaxillary lymph nodes (SmLN) of mice was examined in animals subjected to unilateral superior cervical ganglionectomy (SCGx). Norepinephrine (NE) content in ipsilateral SmLN decreased by 90% 7-20 days after SCGx, while bilateral SCGx resulted in a 91% decrease of SmLN NE content. SmLN of mice subjected to unilateral SCGx exhibited greater plaque-forming cell (PFC) response than the innervated contralateral SmLN, when challenged i.d. or i.p. with sheep red blood cells (SRBC) 10-20 days after surgery. In mice challenged with SRBC at an early phase of sympathetic nerve paralysis (i.e., 2 h after SCGx), PFC response was already increased in the ipsilateral SmLN whereas during the anterograde degeneration of nerve endings (6-24 h after SCGx) an impending depression of PFC number was observed. Contact hypersensitivity and allogeneic delayed-type reactions were also enhanced in the ear ipsilateral to SCGx. Primed SmLN cells of nodes located ipsilaterally to SCGx, when injected to (BALB/c x C57BL/6) F1, resulted in significantly higher spleen index than similarly treated, contralateral SmLN. In contrast, mitogenic stimulation under various experimental protocols failed to reveal significant differences between proliferation of cell populations obtained from ipsilateral and contralateral SmLN of unilaterally SCGx mice. SmLN of mice parasympathetically decentralized by unilateral sections of the chorda tympani-lingual nerve trunk showed lower PFC response than the innervated contralateral SmLN, when challenged with SRBC 8-28 days after surgery. These results suggest a regulatory function of the autonomic nervous system in immune reaction.