Igg Subclasses Targeting the Flagella of Salmonella Enterica Serovar Typhimurium Can Mediate Phagocytosis and Bacterial Killing
- *Corresponding Author:
- Dr. Pietro Mastroeni
Department of Veterinary Medicine
University of Cambridge, Madingley Road
Cambridge CB3 0ES, United Kingdom
E-mail: [email protected]
Received Date May 16, 2016; Accepted Date May 26, 2016; Published Date May 30, 2016
Citation: Goh YS, Armour KL, Clark MR, Grant AJ, Mastroeni P (2016) IgG Subclasses Targeting the Flagella of Salmonella enterica Serovar Typhimurium can Mediate Phagocytosis and Bacterial Killing. J Vaccines Vaccin 7:322. doi: 10.4172/2157-7560.1000322
Copyright: © 2016 Goh YS, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Invasive non-typhoidal Salmonella are a common cause of invasive disease in immuno-compromised individuals and in children. Multi-drug resistance poses challenges to disease control, with a critical need for effective vaccines. Flagellin is an attractive vaccine candidate due to surface exposure and high epitope copy number, but its potential as a target for opsonophacytic antibodies is unclear.
We examined the effect of targeting flagella with different classes of IgG on the interaction between Salmonella Typhimurium and a human phagocyte-like cell line, THP-1. We tagged the FliC flagellar protein with a foreign CD52 mimotope (TSSPSAD) and bacteria were opsonized with a panel of humanised CD52 antibodies with the same antigen-binding V-region, but different constant regions. We found that IgG binding to flagella increases bacterial phagocytosis and reduces viable intracellular bacterial numbers. Opsonisationwith IgG3, followed by IgG1, IgG4, and IgG2, resulted in the highest level of bacterial uptake and in the highest reduction in the intracellular load of viable bacteria. Taken together, our data provide proof-of-principle evidence that targeting flagella with antibodies can increase the antibacterial function of host cells, with IgG3 being the most potent subclass. These data will assist the rational design of urgently needed, optimised vaccines against iNTS disease.