Alteration of immunological properties of bacterial lipopolysaccharide by calcium hydroxide treatment

Abstract

OBJECTIVE: To study alteration of immunological properties of LPS by Ca(OH)2 treatment, and to establish an experimental model in which ThP-1 cell line was cultured in vitro to observe the alteration of immunological properties of LPS. METHODS: ThP-1 cell line was used to establish a culture model in vitro. Amount of TNF-alpha released from stimulated cells acted as the index on immunological properties of the stimuli and alteration of immunological properties of LPS by Ca(OH)2 treatment. RESULTS: Within the range of observed LPS concentrations (10 micrograms/L-10 mg/L), the original immunological properties of LPS decreased significantly after treatment by Ca(OH)2 for a week (P < 0.001). When pH > or = 12.30, the amount of TNF-alpha excreted by monocyte did not differ significantly from the control group (P > 0.05). CONCLUSIONS: After treatment by Ca(OH)2 for a week, the original immunological properties of LPS decreased significantly. High pH value of Ca(OH)2 played a critical role during the alteration of immunological properties of LPS.