coli(UPEC) outer membrane subproteome; 30 individual OMPs present on the bacterial surface during growth in human urine were identified. optimal adjuvant, optimal dose, and optimal route of delivery. We hypothesized that a multi-subunit vaccine elicits antibody that protects against experimental challenge with UPEC strains. We have systematically identified four antigens that can individually protect experimentally infected mice from colonization of the bladder and/or kidneys by UPEC when administered intranasally with STING agonist-1 cholera toxin (CT) as an adjuvant. To advance the vaccine for utility in humans, we will group the individual antigens, all associated with iron acquisition (IreA, Hma, IutA, FyuA), into an effective combination to establish a multi-subunit vaccine. We demonstrated for all four vaccine antigens STING agonist-1 that antigen-specific serum IgG represents a strong correlate of protection in vaccinated mice. High antibody titers correlate with low colony forming units (CFUs) of UPEC following transurethral challenge of vaccinated mice. However , the contribution of cell-mediated immunity cannot be ruled out and must be investigated experimentally. We have demonstrated that antibodies bind to the surface of UPEC expressing the antigens. Sera from women with and without histories of UTI have been tested for antibody levels to vaccine antigens. Our results validate iron acquisition as a target for vaccination against UTI. Keywords: E. coli, urinary tract infection, vaccine, antibody response == 1 . Introduction == Urinary tract infection (UTI) is the second most common infection in humans after those involving the respiratory tract [1]. Half of all women will experience a symptomatic UTI, with incidences peaking in their early 20s. One-fourth of these women will experience recurrence within 612 months [2, 3]. In the U. S., where the annual societal cost of UTIs is likely underestimated at $3. 5 billion [4], four million women have UTIs continuously [5]. These infections range in severity from asymptomatic bacteriuria and cystitis to acute pyelonephritis and urosepsis, the latter of which can be fatal. This high frequency of infection results not only in huge annual economic costs, but in decreased workforce productivity and high patient morbidity [6]. At least 80% of these infections are caused by uropathogenicEscherichia coli(UPEC), which reside alongside commensal strains in the intestinal tract and gain access to the bladder via colonization of the urethra and to the kidney via ascension of the ureters. The urinary tract is among the most common sites of bacterial infection, andE. coliis by far the most common species infecting this site [7]. Individuals at high risk for symptomatic UTI include neonates, preschool girls, sexually active women, and elderly women and men. In 2006 (the most recent date for which comprehensive data are available), there were 11 million physician visits, over 1 . 7 million emergency room visits, and 479, 000 hospitalizations of both men and women in the U. S. for UTI, at an annual cost of $3. 5 billion [4, 8]. These estimates place UTIs first among kidney and urologic Rabbit Polyclonal to GJC3 diseases in terms of total cost. Antibiotic treatment, typically with trimethoprim/sulfamethoxazole (TMPSMX (Bactrim)) or ciprofloxacin, is generally effective for eradication of the infecting strain. However , documentation of increasing antibiotic resistance, allergic reaction to certain pharmaceuticals, alteration of STING agonist-1 normal gut flora, and failure to prevent recurrent infections represent significant barriers to treatment [9]. Indeed, treatment has been complicated by a rise in both the number of antibiotic-resistant strains and the prevalence of antibiotic-resistance mechanisms. For example , in the U. S. and Canada, 10%25% of uncomplicated UTI isolates are resistant to TMPSMX [9, 10, 11]. Even more troubling is the rate of multidrug resistance among UPEC isolates that has risen as physicians adapt prescription choices to address shifting microbial susceptibilities [12]. As a result, UTI prevention by vaccination represents a gap that must be addressed. Working toward a more effective and less costly alternative to antibiotic therapy for UTI management, we have identified protective antigens to specifically target UPEC. Although many women do experience recurrent UTI and UPEC heterogeneity complicates vaccine design, data from our animal model and human studies offer encouragement for successful UPEC vaccine development [13, 14]. Immunization with four UPEC antigens stimulates increases in urinary and serum antibody titers that correlate with reductions in bladder and/or kidney bacterial load [15, 16, 17, 18, 19]. STING agonist-1 Based on preliminary studies, we are optimistic that an effective UPEC.