Lipopolysaccharide of gram negative bacteria ?

Ans. is 'c' i.e., Stimulator for B lymphocytes The biological activity of endotoxin is associated with lipopolysaccharide (LPS). i) Toxicity is associated with lipid component (Lipid A). ii) Immunogenicity is associated with polysaccharide component. The cell wall antigen (0 antigen) of Gram-negative bacteria are components of LPS. LPS elicits a variety of inflammatory responses and activates alternate complement pathway. The susceptibility to infections induced by Gram-negative bacteria is largely determined by innate immune response to bacterial cell wall lipopolysaccharide (LPS). The stimulation of B-cells by LPS enhances their antigen-presenting capacity and is accompanied by B-cell proliferation and secretion of large qunatities of LPS neurilizing antibodies.