Modification biological activity of S and R forms of Proteus mirabilis and Burkholderia cepacia lipopolysaccharides by carrageenans

The modification of biological features of S and R forms of Proteus mirabilis and Burkholderia cepacia LPS by kappa/iota and kappa/beta carrageenans was shown in Limulus activation test, ELISA, human complement activation and apoptotic assay. The role of positively charged substituent Ara4N in lipid A was evaluated as a suspected major domain for interactions with sulphate groups of carrageenans.The experiments obtained by three serological methods indicated that not only lipid A part of LPS but also polysaccharide elements such as core and O-specific chain are involved in interaction with carrageenes. Carrageenans turned out to be non-cytotoxic for A549 cells and were able to inhibit the apoptotic effect caused by lipid A of P. mirabilis and B. cepacia.