Biology subjects

Connolly, K. L.

Publications and source records attributed to Connolly, K. L..

5 recordsLinked to original sources

bioRxiv2024

Protection against N. gonorrhoeae induced by OMV-based Meningococcal Vaccines are associated with cross-species directed humoral and cellular immune responses

Limited protective immunologic responses to natural N. gonorrhoeae infection and a lack of knowledge about mechanisms of protection have hampered development of an effective vaccine. Recent studies in humans and mice have found meningococcal outer membrane vesicle-containing vaccines (OMV) induce cross species immune responses against gonococci and are associated with protection. The exact mechanisms or how humoral and cellular immunity are related to protection, remain unclear. To study this, we immunized mice with two meningococcal OMV-containing vaccines known to accelerate clearance of N. gonorrhoeae, 4CMenB and OMV from an engineered N. meningitidis strain lacking major surface antigens PorA, PorB, and Rmp (MC58 {Delta}ABR). We assessed serologic and cellular immune signatures associated with these immunizations and assessed bacterial clearance in the mice using a vaginal/cervical gonococcal infection model. Mice immunized with 4CMenB or MC58 {Delta}ABR demonstrated shortened courses of recovery of vaginal N. gonorrhoeae compared to control mice immunized with alum alone. Vaccination with 4CMenB or MC58{Delta}ABR OMV elicited serum and vaginal cross-reactive anti-Ng-OMV antibody responses that were augmented after vaginal challenge with N. gonorrhoeae. Further, splenocytes in 4CMenB and MC58 {Delta}ABR immunized mice exhibited elevated cytokine production after restimulation with heterologous N. gonorrhoeae OMV when compared to splenocytes from Alum immunized mice. We further tested for correlations between bacterial burden and the measured anti-gonococcal immune responses within each vaccination group and found different immunologic parameters associated with reduced bacterial burden for each vaccine. Our findings suggest the cross-protection against gonococcal infection induced by different meningococcal OMV vaccines is likely multifactorial and mediated by different humoral and cellular immune responses induced by these two vaccines.

microbiology↗

bioRxiv2023

Evaluating vaccine-elicited antibody activities against Neisseria gonorrhoeae: cross-protective responses elicited by the 4CMenB meningococcal vaccine

The bacterial pathogen Neisseria gonorrhoeae is an urgent global health problem due to increasing numbers of infections, coupled with rampant antibiotic resistance. Vaccines against gonorrhea are being prioritized to combat drug-resistant N. gonorrhoeae. Meningococcal serogroup B vaccines such as 4CMenB are predicted by epidemiology studies to cross-protect individuals from natural infection with N. gonorrhoeae and elicit antibodies that cross-react with N. gonorrhoeae. Evaluation of vaccine candidates for gonorrhea requires a suite of assays for predicting efficacy in vitro and in animal models of infection, including the role of antibodies elicited by immunization. Here we present assays to evaluate antibody functionality after immunization: antibody binding to intact N. gonorrhoeae, serum bactericidal activity, and opsonophagocytic killing activity using primary human neutrophils (polymorphonuclear leukocytes). These assays were developed with purified antibodies against N. gonorrhoeae and used to evaluate serum from mice that were vaccinated with 4CMenB or given alum as a negative control. Results from these assays will help prioritize gonorrhea vaccine candidates for advanced preclinical to early clinical study and will contribute to identifying correlates and mechanisms of immune protection against N. gonorrhoeae.

microbiology↗

bioRxiv2022

A novel oral GyrB/ParE dual binding inhibitor effective against multidrug resistant Neisseria gonorrhoeae and other high-threat pathogens

Drug resistant Neisseria gonorrhoeae is a serious global health concern. New drugs are needed that can overcome existing drug resistance, as well as limit development of new resistance. We describe the small molecule tricyclic pyrimidoindole JSF-2414 [8-(6- fluoro-8-(methylamino)-2-((2-methylpyrimidin-5-yl)oxy)-9H-pyrimido[4,5-b]indol-4-yl)-2- oxa-8-azaspiro[4.5]decan-3-yl)methanol], which simultaneously binds to ATP binding regions of DNA gyrase (GyrB) and topoisomerase (ParE). JSF-2414 displays potent activity against N. gonorrhoeae including drug-resistant strains. A phosphate prodrug JSF-2659 was developed to facilitate oral dosing. In two different animal models of Neisseria gonorrhoeae vaginal infection, JSF-2659 was highly efficacious in reducing microbial burdens to the limit of detection. The parent molecule also showed potent in vitro activity against high-threat Gram positive organisms, and JSF-2659 was shown in a deep tissue model of VRSA and a model of C. difficile-induced colitis to be highly efficacious and protective. JSF-2659 is a novel drug candidate against high-threat multidrug resistant organisms with low potential to develop new resistance.

microbiology↗

bioRxiv2020

Ribosome rescue inhibitors clear Neisseria gonorrhoeae in vivo using a new mechanism

The trans-translation pathway for rescuing stalled ribosomes is conserved and essential in bacterial pathogens but has no mammalian homolog, making it an ideal target for new antibiotics. We previously reported the discovery of a family of acylaminooxadiazoles that selectively inhibit trans-translation, resulting in broad-spectrum antibiotic activity. Optimization of the pharmacokinetic and antibiotic properties of the acylaminooxadiazoles produced MBX-4132, which cleared multiple-drug resistant Neisseria gonorrhoeae infection in mice after a single oral dose. Cryo-EM studies of non-stop ribosomes showed that acylaminooxadiazoles bind to a unique site near the peptidyl-transfer center and significantly alter the conformation of ribosomal protein L27, suggesting a novel mechanism for specific inhibition of trans-translation by these molecules. One Sentence SummaryRibosome rescue inhibitors reveal a new conformation of the ribosome and kill drug-resistant Neisseria gonorrhoeae in vivo.

microbiology↗

bioRxiv2020

The serogroup B meningococcal outer membrane vesicle-based vaccine 4CMenB induces cross-species protection against Neisseria gonorrhoeae

There is a pressing need for a gonorrhea vaccine due to the high disease burden associated with gonococcal infections globally and the rapid evolution of antibiotic resistance in Neisseria gonorrhoeae (Ng). Current gonorrhea vaccine research is in the stages of antigen discovery and the identification of protective immune responses, and no vaccine has been tested in clinical trials in over 30 years. Recently, however, it was reported in a retrospective case-control study that vaccination of humans with a serogroup B Neisseria meningitidis (Nm) outer membrane vesicle (OMV) vaccine (MeNZB) was associated with reduced rates of gonorrhea. Here we directly tested the hypothesis that Nm OMVs induce cross-protection against gonorrhea in a well-characterized female mouse model of Ng genital tract infection. We found that immunization with the licensed Nm OMV-based vaccine 4CMenB (Bexsero(R)) significantly accelerated clearance and reduced the Ng bacterial burden compared to administration of alum or PBS. High titers of serum IgG1 and IgG2a and vaginal IgG1 that cross-reacted with Ng OMVs were induced by vaccination via either the subcutaneous or intraperitoneal routes, and a 4-fold increase in the serum bactericidal50 titers was detected against the challenge strain. Antibodies from vaccinated mice recognized several surface proteins in a diverse collection of Ng strains, including PilQ, BamA, MtrE, PorB, and Opa, and 4CMenB-induced antibodies bound PilQ and MtrE in native form on the surface of viable bacteria. In contrast, the antibodies were only cross-reactive against lipooligosaccharide species from a few Ng strains. Our findings directly support epidemiological evidence that Nm OMVs confer cross-species protection against Ng and implicate several Ng surface antigens as potentially protective targets. This work also validates the murine infection model as a relevant experimental system for investigating mechanisms of vaccine-mediated protection against gonorrhea. Author summaryOver 78 million Neisseria gonorrhoeae (Ng) infections occur globally each year and control of gonorrhea through vaccination is challenged by a lack of strong evidence that immunity to gonorrhea is possible. This contention was recently challenged by epidemiological evidence suggesting that an outer membrane vesicle (OMV) vaccine from the related species Neisseria meningitidis (Nm) protected humans against gonorrhea. Here we provide experimental evidence in support of this hypothesis by demonstrating that a licensed, modified version of this Nm OMV-based vaccine accelerates clearance of Ng in a mouse infection model. These results confirm the possibility cross-species protection and are important in that they support the biological feasibility of vaccine-induced immunity against gonorrhea. We also showed that several Ng outer membrane proteins are recognized by antisera from vaccinated mice that may be protective targets of the vaccine. Additionally, our demonstration that a vaccine that may reduce the risk of gonorrhea in humans protects mice against Ng, a highly host-restricted pathogen, validates the mouse model as a potentially useful tool for examining mechanisms of protection, which could be exploited in the development of other candidate gonorrhea vaccines.

microbiology↗