The development of an effective gonorrhea yaccine is challenged by the antigenic variability of the Neisseria gonorrhoeae (Gc) surface and a lack of information on the correlates of protection against infection. Gc porin is a good vaccine candidate based on its abundance in the outer membrane (OM), limited variability, and its roles in epithelial cell invasion and serum resistance via binding to C4bp-binding protein (C4BP) and factor H (fH). Other promising vaccine targets are MtrE, the OM channel of the MtrCMtrD- MtrE active efflux pump, and OmpA, a conserved OM protein that confers adherence to and invasion of human genital tract cells. Our primary objective is to target surface-exposed loops of GC porin in active and passive immunization strategies against gonorrhea. We will also test the protective efficacy of MtrE and OmpA. Specifically, we will 1) characterize Abs against selected porin loops for in vitro and in vivo correlates of protection and the capacity to block C4BP- and fH-binding to serum resistant strains. The bactericidal and opsonophagocytic activity of Abs against cyclic porin peptides will be measured against Gc strains of different porin types. The capacity of Abs to inhibit porin-mediated invasion of human cervical cells and to block the binding of human fH and C4BP to serum resistant Gc will be tested. We will perform passive protection studies with normal, complement- and granulocyte-deficient mice to identify mechanisms of antibody-mediated protection. We will also ii) develop an active immunization strategy based on cyclic porin loop peptides to protect mice from Gc infection. The optimum dose of peptide and type of adjuvant needed to induce high titer serum and mucosal antibodies with anti-Gc activity will be determined. Mice will be immunized with the most promising peptides, and immunized and unimmunized mice will be challenged intravaginally with the homologous Gc strain to determine if immunization affects susceptibility to infection or colonization load. The local and systemic immune response to two peptides that show protection and an analogous peptide that does not will be thoroughly characterized to define correlates of protection, ill.) Finally, we will investigate the protective potential of MtrE and OmpA as vaccine candidates based on their demonstrated importance in experimental murine infection. We will utilize MtrE- and OmpA-specific antibodies to investigate in vitro correlates of protection and perform immunization/challenge studies with purified MtrE, OmpA and surface-exposed regions of these molecules to measure their potential as vaccine antigens against N. gonorrhoeae in vivo.
Gonorrhea is the second leading reportable infection in the U.S., a major cause of pelvic inflammatory disease, and a co-factor for HIV transmission. There is no gonorrhea vaccine and the rapid emergence of antibiotic resistant strains is a real concern. This project will lead to the development of candidate gonorrhea vaccines and an understanding of immune parameters that do and do not correlate with protection in vivo.
|Kissinger, Patricia J; White, Scott; Manhart, Lisa E et al. (2016) Azithromycin Treatment Failure for Chlamydia trachomatis Among Heterosexual Men With Nongonococcal Urethritis. Sex Transm Dis 43:599-602|
|Kandler, Justin L; Acevedo, Rosuany VÃ©lez; Dickinson, Mary Kathryne et al. (2016) The genes that encode the gonococcal transferrin binding proteins, TbpB and TbpA, are differentially regulated by MisR under iron-replete and iron-depleted conditions. Mol Microbiol 102:137-51|
|Kandler, Justin L; Holley, Concerta L; Reimche, Jennifer L et al. (2016) The MisR Response Regulator Is Necessary for Intrinsic Cationic Antimicrobial Peptide and Aminoglycoside Resistance in Neisseria gonorrhoeae. Antimicrob Agents Chemother 60:4690-700|
|Woolf-King, Sarah E; Muyindike, Winnie; Hobbs, Marcia M et al. (2016) Vaginal Prostate Specific Antigen (PSA) Is a Useful Biomarker of Semen Exposure Among HIV-Infected Ugandan Women. AIDS Behav :|
|Scheidell, Joy D; Lejuez, Carl W; Golin, Carol E et al. (2016) Borderline Personality Disorder Symptom Severity and Sexually Transmitted Infection and HIV Risk in African American Incarcerated Men. Sex Transm Dis 43:317-23|
|Samo, Melissa; Choudhary, Neelima R; Riebe, Kristina J et al. (2016) Immunization with the Haemophilus ducreyi trimeric autotransporter adhesin DsrA with alum, CpG or imiquimod generates a persistent humoral immune response that recognizes the bacterial surface. Vaccine 34:1193-200|
|Khan, M R; Golin, C E; Friedman, S R et al. (2015) STI/HIV Sexual Risk Behavior and Prevalent STI Among Incarcerated African American Men in Committed Partnerships: The Significance of Poverty, Mood Disorders, and Substance Use. AIDS Behav 19:1478-90|
|Unemo, Magnus; Shafer, William M (2015) Future treatment of gonorrhea--novel emerging drugs are essential and in progress? Expert Opin Emerg Drugs 20:357-60|
|Cash, Devin R; Noinaj, Nicholas; Buchanan, Susan K et al. (2015) Beyond the Crystal Structure: Insight into the Function and Vaccine Potential of TbpA Expressed by Neisseria gonorrhoeae. Infect Immun 83:4438-49|
|Gallo, Maria F; Warner, Lee; Hobbs, Marcia M et al. (2015) Differences in misreporting of sexual behavior over time: implications for HIV trials. Sex Transm Dis 42:160-1|
Showing the most recent 10 out of 125 publications