Marginal zone (MZ) B cells produce a first wave of antibodies for protection from blood-borne pathogens. However, the role of MZ B cells in inflammatory responses has not been elucidated. Here we show that MZ B cells produce pro-inflammatory cytokines, such as interleukin-6 (IL-6), and exacerbate systemic inflammatory responses to lipopolysaccharide (LPS). After intravenous injection of LPS or E. coli, mice deficient in MZ B cells or IL-6 only in MZ B cells have attenuated systemic inflammatory responses and prolonged survival compared with wild-type mice. LPS directly stimulates MZ B cells via Toll-like receptor 4 (TLR4) and MyD88 pathways for IL-6 production. Furthermore, TLR4 requires physical and functional association with Fcα/μR (CD351) for its oligomer formation, NF-κB signalling and IL-6 production from MZ B cells; this association is responsible for systemic inflammatory responses and endotoxic shock. These results reveal a pro-inflammatory role of MZ B cells in endotoxic shock.

Isolation of splenic macrophage subpopulations using an enzyme cocktail

CD300a blockade ameliorates stroke pathology through enhancing efferocytosis in the brain by infiltrating myeloid cells.

No abstract

Chylothorax is an abnormal condition of lymphatic fluid collection in the pleural space, and the somatostatin analog octreotide is thought to have a beneficial effect on chylothorax. However, the octreotide dosage and administration route for chylothorax have been inconsistent to date. We report three neonatal cases of persistent chylothorax successfully treated with high-dose octreotide infusion therapy (20 μg/kg/h). Case 1 was congenital chylothorax, Case 2 was secondary chylothorax after an operation for congenital diaphragmatic hernia, and Case 3 was chylothorax after a cardiac operation. In all cases, the chylothorax was not decreased by a low-dose octreotide infusion, but after a high-dose octreotide infusion, the chylothorax decreased and eventually vanished, with no side effects. Conclusion: We suggest that the dose of octreotide in neonatal chylothorax can be safely increased to a maximum of 20 µg/kg/h.