LPS activates TLR4 signaling pathway eliciting antiviral host responses in mammals although information on such responses in avian species is scarce. Objectives of the work described in the thesis were to 1. characterize the LPS induced expression of LPS receptors and NO in two avian cell lines, LMH and MQ-NCSU, and 2. observe whether NO can elicit antiviral response against ILTV replication. We found that LPS was capable of inducing the expression of TLR4, CD14 and NO production only in MQ-NCSU cells. We also showed that TLR4 mediated NO production in MQ-NCSU cells confers antiviral response against ILTV in susceptible LMH cells. Using a selective inhibitor of inducible NO synthase and a NO donor as a source of NO, we confirmed that this effect is positively correlated with NO. Our data showed that LPS can be a potential innate immune stimulant that can be used against ILTV infection in chickens
