Enterotoxigenic Escherichia coli–blood group A interactions intensify diarrheal severity
Pardeep Kumar, F. Matthew Kuhlmann, Subhra Chakraborty, A. Louis Bourgeois, Jennifer Foulke-Abel, Brunda Tumala, Tim J. Vickers, David A. Sack, Barbara DeNearing, Clayton D. Harro, W. Shea Wright, Jeffrey C. Gildersleeve, Matthew A. Ciorba, Srikanth Santhanam, Chad K. Porter, Ramiro L. Gutierrez, Michael G. Prouty, Mark S. Riddle, Alexander Polino, Alaullah Sheikh, Mark Donowitz, James M. Fleckenstein
Pardeep Kumar, F. Matthew Kuhlmann, Subhra Chakraborty, A. Louis Bourgeois, Jennifer Foulke-Abel, Brunda Tumala, Tim J. Vickers, David A. Sack, Barbara DeNearing, Clayton D. Harro, W. Shea Wright, Jeffrey C. Gildersleeve, Matthew A. Ciorba, Srikanth Santhanam, Chad K. Porter, Ramiro L. Gutierrez, Michael G. Prouty, Mark S. Riddle, Alexander Polino, Alaullah Sheikh, Mark Donowitz, James M. Fleckenstein
View: Text | PDF | Corrigendum
Research Article Infectious disease

Enterotoxigenic Escherichia coli–blood group A interactions intensify diarrheal severity

Abstract

Enterotoxigenic Escherichia coli (ETEC) infections are highly prevalent in developing countries, where clinical presentations range from asymptomatic colonization to severe cholera-like illness. The molecular basis for these varied presentations, which may involve strain-specific virulence features as well as host factors, has not been elucidated. We demonstrate that, when challenged with ETEC strain H10407, originally isolated from a case of cholera-like illness, blood group A human volunteers developed severe diarrhea more frequently than individuals from other blood groups. Interestingly, a diverse population of ETEC strains, including H10407, secrete the EtpA adhesin molecule. As many bacterial adhesins also agglutinate red blood cells, we combined the use of glycan arrays, biolayer inferometry, and noncanonical amino acid labeling with hemagglutination studies to demonstrate that EtpA is a dominant ETEC blood group A–specific lectin/hemagglutinin. Importantly, we have also shown that EtpA interacts specifically with glycans expressed on intestinal epithelial cells from blood group A individuals and that EtpA-mediated bacterial-host interactions accelerate bacterial adhesion and effective delivery of both the heat-labile and heat-stable toxins of ETEC. Collectively, these data provide additional insight into the complex molecular basis of severe ETEC diarrheal illness that may inform rational design of vaccines to protect those at highest risk.

Authors

Pardeep Kumar, F. Matthew Kuhlmann, Subhra Chakraborty, A. Louis Bourgeois, Jennifer Foulke-Abel, Brunda Tumala, Tim J. Vickers, David A. Sack, Barbara DeNearing, Clayton D. Harro, W. Shea Wright, Jeffrey C. Gildersleeve, Matthew A. Ciorba, Srikanth Santhanam, Chad K. Porter, Ramiro L. Gutierrez, Michael G. Prouty, Mark S. Riddle, Alexander Polino, Alaullah Sheikh, Mark Donowitz, James M. Fleckenstein

×

Figure 5

A blood group–dependent interactions of EtpA and ETEC with intestinal epithelia.

Options: View larger image (or click on image) Download as PowerPoint
A blood group–dependent interactions of EtpA and ETEC with intestinal ep...
(A) EtpA binds to regions of blood group A expression on the surface of HT-29 epithelial cells. Shown in columns from left to right are blood group A (green, antibodies against blood group A and fluorescent conjugate αbgA/AF488); nuclei (blue, DAPI); biotinylated EtpA (red, SA-coated Qdots594); and merged images. Middle row: no EtpA control. Bottom row: no EtpA binding to the surface of HT29A–/– cells engineered to remove the α1→3 GalNac glycosyltransferase required for A antigen expression. Original magnification, ×100. (B) EtpA preferentially engages cells expressing A blood group. Key: upper left indicates the target (bait) cell lines used to attract ANL-labeled bacterial (prey) proteins from H10407 (WT) or the etpA mutant. Labeled rEtpA and the arrow at left are shown to indicate the predicted migration of EtpA. Lanes at far right show input proteins from the EtpA-expressing H10407 WT and the etpA mutant. (C) Localization of EtpA-expressing ETEC to areas of blood group A expression on the surface of HT-29 cells. Original magnification, ×63. Images in A–C represent 1 of 3 experimental replicates. (D) EtpA and blood group A are required for optimal adhesion. Data are representative of 4 independent experiments. HT-29A–/– data include results from 2 independently generated engineered blood group A glycosyl transferase mutant lines (1e6, circular symbols; and 1g10, square symbols; n = 8 technical replicates in total). *P = 0.03, ANOVA, Kruskal-Wallis. (E) Blood group A accelerates adhesion of ETEC to target intestinal epithelial cells (n = 8 technical replicates for HT-29 cells and n = 6 technical replicates for HT-29–/– cells; representative of 2 independent experiments); symbols represent mean ± SEM. **P = 0.003; ***P = 0.0003, Mann-Whitney U test, 2-tailed comparison. (F) Presence of A blood group and EtpA are required for optimal delivery of heat-labile toxin by ETEC (n = 5 technical replicates representative of 3 independent experiments). **P < 0.01, ANOVA, Kruskal-Wallis.