Encapsulation of Bacteriophage in Liposome Accentuates Its Entry in to Macrophage and Shields It from Neutralizing Antibodies

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.

Phage therapy: What factors shape phage pharmacokinetics and bioavailability? Systematic and critical review

“…In addition to delivering control release systems, encapsulation protects bacteriophages and allows for longer circulation in human or animal body. This can be both by protection from chemical stress and by making phage less visible to the immune system and less susceptible to neutralization …”

Inactivation of Escherichia coli O157:H7 treated by poly‐L‐lysine‐coated bacteriophages liposomes in pork

“…To measure C total , bile salt (Sigma‐Aldrich) was added into the bacteriophages liposomes PBS solution to disrupt the structure of liposomes. Bile salt has been tested without significant impact on the activity of the bacteriophages (Singla, Harjai, Katare, & Chhibber, ). Subsequently, the mixture was diluted and moved into NA plates covered with E. coli O157:H7 (strain CICC 23872).…”

“…Bile salt has been tested without significant impact on the activity of the bacteriophages (Singla, Harjai, Katare, & Chhibber, 2016). Subsequently, the mixture was diluted and moved into NA plates covered with E. coli O157:H7 (strain CICC 23872).…”

Ameliorating the antimicrobial resistance crisis: phage therapy

“…Another shortcoming phage therapy faces is its inability to penetrate mammalian cells to gain access to intracellular pathogens as it works as long as the bacteria are directly accessible to the phages. Cationic liposomes were used to bridge this gap between phages and intracellular pathogens as they are designed to fuse with the negatively charged cell membrane and deliver phages inside . An additional bonus from this liposome entrapment would be to escape binding from the anti‐phage antibodies.…”