Investigating the CEACAM1 adhesive properties of Moraxella catarrhalis

: Identifying a novel CEACAM1 adhesion protein found in Mx13L

Abstract

Moraxella catarrhalis is an upper respiratory pathogen often implicated as the cause otitis media infections, as well as exacerbating chronic obstructive pulmonary disease. One of the human receptors identified for Moraxella catarrhalis is Carcinoembryonic antigen-related cell adhesion molecule 1 (CC1), normally the surface adhesins UspA1 and UspA2V use the CC1 specific binding sequence within the previously identified rD-7region of UspA1 to interact with CC1. ATCC25240 is a strain of Moraxella catarrhalis which lacks the rD-7 region within its UspA1. This study revealed that a variant of ATCC25240 dubbed MX13L, which also lacks the rD-7 regions binds to CC1. The unknown adhesin present in MX13L interacted with CC1 in a heat modifiable manner. Using a combination of bioinformatics and the ez tn5 transposon to generate a transposon library of MX13L in conjunction with immune overlay assays, we identified that WP_003661028 (BOMP 8) as a putative candidate protein for the novel adhesin.

Date of Award	29 Sep 2020
Original language	English
Awarding Institution	The University of Bristol
Supervisor	Darryl J Hill (Supervisor) & Jim Spencer (Supervisor)