Vagotomy decreases splenocytes and MHCII+/CD11B+ cells in the spleen

Abstract

The Vagus Nerve is a major component, in conjunction with the spleen, in modulating the systemic anti-inflammatory response. Adrenergic fibers of the splenic nerve innervate the spleen, where they stimulate a distinct population of memory T cells. These memory T cells subsequently release ACh, thereby reducing macrophage activation and inhibiting TNFα. Therefore this pathway, as it relates to the spleen, is a two-neuron circuit: initiating first in the dorsal motor nucleus of the Vagus, subsequently synapsing at the celiac ganglion, and finally synapsing on the memory T cells. There are additional lines of evidence demonstrating cholinergic modulation of immune cells in the spleen. For example emerging evidence supports a regulating role of the vagus nerve in mobilizing marginal zone B cells and their subsequent secretion of antibodies, heralding an innate immune response. However, a direct link between splenic B cell number and the vagus nerve has not been previously established. Therefore, we assessed the effects of a left unilateral vagotomy on total splenocytes and MHCII+/CD11+ B cells in the spleen 3 days after vagotomy. Results The results indicate that at 3 days after left unilateral vagotomy, there is a significant decrease in the overall number of splenocytes. The results also show that this vagotomy results in a trend toward a significant reduction in MHCII+/CD11+ B cells in the spleen. Conclusions Our conclusions based upon these results show that there is a direct influence of left vagus nerve innervation on the number of splenic B cells and that left vagotomy results in an overall decrease in either the proliferation of splenocytes in general including the B-cells, or in cell death of splenocytes including the B cells.