Enterotoxigenic Escherichia coli (ETEC) is an endemic health threat in underdeveloped nations. Despite the significant effort extended to vaccine trials using ETEC colonization factors, these approaches have generally not been especially effective in mediating cross-protective immunity. We used quantitative proteomics to identify 24 proteins that differed in abundance in membrane protein preparations derived from wild-type vs. a type II secretion system mutant of ETEC. We expressed and purified a subset of these proteins and identified nine antigens that generated significant immune responses in mice. Sera from mice immunized with either the MltA-interacting protein MipA, the periplasmic chaperone seventeen kilodalton protein, Skp, or a long-chain fatty acid outer membrane transporter, ETEC_2479, reduced the adherence of multiple ETEC strains differing in colonization factor expression to human intestinal epithelial cells. In intranasal challenge assays of mice, immunization with ETEC_2479 protected 88% of mice from an otherwise lethal challenge with ETEC H10407. Immunization with either Skp or MipA provided an intermediate degree of protection, 68 and 64%, respectively. Protection was significantly correlated with the induction of a secretory immunoglobulin A response. This study has identified several proteins that are conserved among heterologous ETEC strains and may thus potentially improve cross-protective efficacy if incorporated into future vaccine designs.

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Abstract.Communication is central to ai1 group interactions, including negotiations. Group interfaces can lirmt or enhance communication flows among participants. Hence, group interface design requires the identification of the communication flows among participants, which in turn requires an identification of the various dimensions of intragroup communication. This article outlines a framework to guide researchers in examining the communication needs of group members in computer-supported collaborative work (CSCW), highlighting its application to the context of negotiation. An analysis of communication flows is provided along four dimensions: concurrency, message, channel and participant characteristics. The framework is intended to encourage a detailed focus on key aspects of the group interface, to provide a scheme for categorizing the contributions of empirical work, and to identify factors worthy of empirical scrutiny.