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Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages
Published on: October 25, 2017
Encapsulation of Bacteriophage in Liposome Accentuates Its Entry in to Macrophage and Shields It from Neutralizing
Saloni Singla1, Kusum Harjai1, Om Prakash Katare2
1Department of Microbiology, Panjab University, Chandigarh, India.
Abstract:
Phage therapy has been a centre of attraction for biomedical scientists to treat infections caused by drug resistant strains. However, ability of phage to act only on extracellular bacteria and probability of interference by anti-phage antibodies in vivo is considered as a important limitation of bacteriophage therapy. To overcome these hurdles, liposome were used as delivery vehicle for phage in this study. Anti-phage antibodies were raised in mice and pooled serum was evaluated for its ability to neutralize free and liposome entrapped phage. Further, ability of phage and liposome-entrapped phage to enter mouse peritoneal macrophages and kill intracellular Klebsiella pneumoniae was compared. Also, an attempt to compare the efficacy of free phage and liposome entrapped phage, alone or in conjunction with amikacin in eradicating mature biofilm was made. The entrapment of phage in liposome provided 100% protection to phage from neutralizing antibody. On the contrary un-entrapped phage got neutralized within 3 h of its interaction with antibody. Compared to the inability of free phage to enter macrophages, the liposome were able to deliver entrapped phage inside macrophages and cause 94.6% killing of intracellular K. pneumoniae. Liposome entrapped phage showed synergistic activity along with amikacin to eradicate mature biofilm of K. pneumoniae. Our study reinforces the growing interest in using phage therapy as a means of targeting multidrug resistant bacterial infections as liposome entrapment of phage makes them highly effective in vitro as well as in vivo by overcoming the majority of the hurdles related to clinical use of phage.
Insights
Liposome encapsulation shields bacteriophage (phage) therapy from neutralizing antibodies and enhances delivery into macrophages. This approach significantly improves the efficacy of phage therapy against drug-resistant bacteria, including biofilms.
Area of Science:
- Biomedical Science
- Microbiology
- Drug Delivery Systems
Background:
- Bacteriophage (phage) therapy is promising for drug-resistant infections but limited by extracellular action and anti-phage antibodies.
- Phage neutralization by antibodies and inability to target intracellular bacteria are key challenges in clinical phage therapy.
Purpose of the Study:
- To enhance bacteriophage therapy efficacy by encapsulating phages within liposomes.
- To evaluate liposome-entrapped phages' protection against neutralizing antibodies and their ability to target intracellular bacteria.
- To compare the efficacy of liposome-entrapped phages versus free phages in eradicating bacterial biofilms, alone and with amikacin.
Main Methods:
- Raising anti-phage antibodies in mice and assessing neutralization of free and liposome-entrapped phages.
- Comparing the uptake of free and liposome-entrapped phages by mouse peritoneal macrophages.
- Evaluating the killing of intracellular Klebsiella pneumoniae by liposome-entrapped phages.
- Assessing the eradication of mature K. pneumoniae biofilms using free and liposome-entrapped phages, with and without amikacin.
Main Results:
- Liposome encapsulation provided complete protection against antibody neutralization; free phages were neutralized within 3 hours.
- Liposomes successfully delivered phages into macrophages, achieving 94.6% killing of intracellular K. pneumoniae, unlike free phages.
- Liposome-entrapped phages exhibited synergistic activity with amikacin against mature K. pneumoniae biofilms.
Conclusions:
- Liposome entrapment effectively overcomes major limitations of bacteriophage therapy, including antibody neutralization and intracellular bacterial targeting.
- This strategy significantly enhances the in vitro and in vivo effectiveness of phage therapy for multidrug-resistant bacterial infections.
- Liposome-mediated phage delivery represents a promising advancement for the clinical application of phage therapy.
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