A polymer coating applied to Salmonella prevents the binding of Salmonella-specific antibodies.
The use of Salmonella as a potential antitumor agent has been investigated, but innate immunity against this bacterium reduces the efficacy of its tumor-targeting and antitumor activities. The purpose of this study was to investigate the modulation of the tumor-targeting efficiency of Salmonella enterica serovar choleraesuis by modifying the immune response to these bacteria by coating them with poly(allylamine hydrochloride) (PAH), designated PAH-S.C. To evaluate this modulation, we used naïve mice and mice immunized with Salmonella to study the role of the preexisting immune response to the antitumor activity of PAH-S.C. When anti-Salmonella antibodies were present, the invasion activity, cytotoxicity, and gene transfer of Salmonella was significantly decreased, both in vitro and in vivo. Treatment with PAH-S.C. resulted in delayed tumor growth and enhanced survival in immunized mice. Furthermore, immunohistochemical studies of the tumors revealed the infiltration of neutrophils and macrophages in immunized mice treated with PAH-S.C. These results indicate that Salmonella encapsulation effectively circumvented the Salmonella-specific immune response.
Department of Microbiology, School of Medicine, China Medical University, Taichung, Taiwan. chlee@mail.cmu.edu.tw
Che-Hsin
CH
Lee
Yu-Hsin
YH
Lin
Jeng-Long
JL
Hsieh
Man-Chin
MC
Chen
Wan-Lin
WL
Kuo
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D057134:Antibodies, Neutralizing / Q000276:immunology; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001691:Biological Therapy; D005260:Female; D007114:Immunization; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009374:Neoplasms, Experimental / Q000276:immunology / Q000382:microbiology* / Q000628:therapy*; D009504:Neutrophils / Q000276:immunology*; D011108:Polymers; D019779:Salmonella enterica / Q000276:immunology* / Q000502:physiology*
D000907:Antibodies, Bacterial; D057134:Antibodies, Neutralizing; D000970:Antineoplastic Agents; D011108:Polymers