<prompt> Lipopolysaccharide of gram negative bacteria -HaptenHeterophile antibodyStimulator for B lymphocytesInduce cell mediated immunity  <response>: Ans. is c i.e., Stimulator for B lymphocytes o The biological activity of endotoxin is associated with lipopolysaccharide LPS.Toxicity is associated with lipid component Lipid A.Immunogenicity is associated with polysaccharide component.o The cell wall antigen O antigen of Gram-negative bacteria are components of LPS.o LPS elicits a variety of inflammatory responses and activates alternate complement pathway,o The susceptibility to infections induced by Gram-negative bacteria is largely determined by innate immune response to bacterial cell wall lipopolysaccharide LPS.o 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. 