An attenuated oncolytic Edmonston (Ed) strain of measles virus (MV) encoding the N-terminus of the human lambda immunoglobulin light chain containing the Helicobacter pylori neutrophil-activating protein (NAP), with potential immunostimulating and antineoplastic activities. Upon administration, the oncolytic measles virus encoding H. pylori NAP selectively infects and replicates in tumor cells, leading to syncytia formation and tumor cell lysis. The expressed NAP, a toll-like receptor-2 (TLR2) agonist, may stimulate the secretion of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-a), interleukin (IL)-1 and IL-6, leading to local inflammatory reaction in the tumor microenvironment (TME). H. pylori NAP, a bacterial antigen and potent immunomodulator, may enhance the antitumor effect of oncolytic MV.