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Principal Investigator: Lisa Ann Lewis
Organization: PLANET BIOTECHNOLOGY, INC.
Fiscal Year: 2024
Award: $300,000
Funding agency: National Institute of Allergy and Infectious Diseases
ABSTRACT
Gonorrhea affects over 87 million people annually globally. In 2021, over 700,000 cases of gonorrhea were
reported to the CDC, a 118% increase since the historic low in the US in 2009. However, the true incidence of
cases annually in the US is estimated to be ~1.5 million. The spread of antimicrobial resistance has severely
limited treatment options – currently, ceftriaxone is the only approved first line of treatment. A safe and effective
therapeutic against gonorrhea is urgently needed. Gonococci (Ng) possess several mechanisms to evade killing
by complement (C’), including binding of factor H (FH) and C4b-binding protein (C4BP), key host inhibitors of
the alternative and classical pathway respectively. We showed previously that a chimeric protein comprising
human IgG3 Fc fused to FH domains 18-20 (containing a point mutation in domain 19 to prevent lysis of host
cells) (Fc3/FH*) killed Ng in a complement-dependent manner and reduced the duration and bacterial burden in
the mouse vaginal colonization model of gonorrhea. Ng can be broadly classified into two serovars based on the
sequence of the outer membrane protein (PorB): PorB1A and PorB1B. PorB1B strains account for 70-90% of
gonococcal infections. PorB1A strains are strongly associated with disseminated gonococcal infection (DGI) and
have caused serious sequelae including dermatitis, arthritis and endocarditis. Fc3/FH* is effective in vitro against
all PorB1B Ng strains tested, but it killed only 13% of tested PorB1A strains. We have developed and tested 2
additional C’ based immunotherapeutic molecules with better activities against PorB1A strains: FH (6-7)/Fc3 and
C4BP-IgM. We have shown that FH(6-7)/Fc3 binds to PorB1A strains and killed 60% of PorB1A strains tested.
C4BP/IgM binds 90% of PorB1A strains and killed 92% PorB1A Ng. The main goals of this project are to develop
a FH6-7 or a C4BP based-Fc fusion that is effective against PorB1A Ng to be part of a combination therapeutic
with Fc3/FH* in order to provide broad protection against both PorB1A and PorB1B strains. In Aim 1, we will
design and produce novel C4BP/Fc3 fusions with improved characteristics. Instead of using C4BP-IgM (which is
impractical to produce commercially), we will develop and produce multimeric C4BP/IgG fusion proteins in tobacco
plants . In Aim 2, we will evaluate in vitro efficacy of FH(6-7)/Fc3and C4BP/Fc3, alone and in combination with
Fc3/FH*. We will use a panel of 60 diverse Ng, consisting of 40 PorB1A and 20 PorB1B strains for testing. We
will test the binding of the fusion proteins to Ng by flow cytometry, and their bactericidal activity in the presence
of serum. The lead molecules will be evaluated under conditions mimicking those in the vagina and we will test
for any in vitro cytotoxicity. In Aim 3, we will test the efficacy of lead FH(6-7)/Fc3and C4BP-based/Fc3
immunotherapeutic molecules in human FH/C4BP transgenic mice. The murine Ng vaginal colonization model
is currently the only non-human model available to evaluate the in vivo efficacy of anti-gonococcal vaccines and
therapeutic molecules. We will evaluate the lead FH(6-7)/Fc3and C4BP/Fc3 alone and in combination with
Fc3/FH* against 1 PorB1A and 1PorB1B strains. Successful completion of the work in this proposal will identify
a lead gonococcal immunotherapy against multidrug-resistant Ng for further pre-clinical development.
Terms: <19S Gamma Globulin><7S Gamma Globulin><AIDS Virus><Acquired Immune Deficiency Syndrome Virus><Acquired Immunodeficiency Syndrome Virus><Affect><Antibiotic Agents><Antibiotic Drugs><Antibiotic Resistance><Antibiotics><Antimicrobial Resistance><Arthritis><Assay><Binding><Bioassay><Biological Assay><Biotech><Biotechnology><Blood Serum><C 4b-binding protein><C4-binding protein><C4b-binding protein><Cannot achieve a pregnancy><Cefatriaxone><Ceftriaxone><Cell Body><Cells><Characteristics><Chimera Protein><Chimeric Proteins><Chlamydia><Classification><Clinical><Collaborations><Complement><Complement Factor H><Complement Inactivators><Complement Inhibitors><Complement Proteins><Cytolysis><Dermatitis><Development><Devices><Difficulty conceiving><Drug Resistance in N. Gonorrhoeae><Drug resistance in Neisseria Gonorrhoeae><Drug resistant N. Gonorrhoeae><Drug-resistant N. Gonorrhoeae><Drug-resistant Neisseria Gonorrhoeae><Ectopic Pregnancy><Endocarditis><Engineering><Epithelial Cells><Factor H><Flow Cytofluorometries><Flow Cytofluorometry><Flow Cytometry><Flow Microfluorimetry><Flow Microfluorometry><Freeze Drying><Freeze Dryings><Fusion Protein><Goals><Gonococcal Infection><Gonococcus><Gonorrhea><HIV><Health><Human><Human Immunodeficiency Viruses><IgG><IgG3><IgM><Immune Evasion><Immune mediated therapy><Immunoglobulin G><Immunoglobulin M><Immunologically Directed Therapy><Immunotherapeutic agent><Immunotherapy><In Vitro><Incidence><Infection><Infertility><Investigators><Knowledge><LAV-HTLV-III><Laboratories><Lead><Ligands><Lymphadenopathy-Associated Virus><Lyophilization><Lysis><Lytotoxicity><Mediating><Membrane Protein Gene><Membrane Proteins><Membrane-Associated Proteins><Mice><Mice Mammals><Miscellaneous Antibiotic><Miyagawanella><Modeling><Modern Man><Molecular Interaction><Multi-Drug Resistance><Multidrug Resistance><Multiple Drug Resistance><Multiple Drug Resistant><Murine><Mus><N gonorrhea><N gonorrhoeae><N. gonorrhea><N. gonorrhoeae><Neisseria gonorrhea><Neisseria gonorrhoeae><Neisseria gonorrhoeae antibiotic resistance><Pathogenicity Factors><Pathway interactions><Pb element><Persons><Planets><Plants><Point Mutation><Prevalence><Prevention><Protein Binding Domain><Protein Binding Motif><Protein-Protein Interaction Domain><Proteins><Recommendation><Reporting><Research Personnel><Researchers><Resistance><Resistance to Multi-drug><Resistance to Multidrug><Resistance to Multiple Drug><Resistance to antibiotics><Resistant to Multiple Drug><Resistant to antibiotics><Resistant to multi-drug><Resistant to multidrug><Serum><Sexually Transmitted Diseases><Sexually Transmitted Disorder><Sexually Transmitted Infection><Surface Proteins><Systematics><Technology><Testing><Therapeutic><Tobacco><Transgenic Mice><Transmission><United States><Universities><VDAC1><VDAC1 gene><Vaccines><Vagina><Vaginal Ring><Venereal Diseases><Venereal Disorders><Venereal Infections><Virulence Factors><Virus-HIV><Woman><Work><anti-microbial resistant><antibiotic drug resistance><antibiotic resistant><antibiotic resistant N. gonorrhoeae><antibiotic resistant Neisseria gonorrhoeae><antibiotic-resistant N. gonorrhoeae><arthritic><bactericidal><bactericide><bedsonia><chronic pelvic pain><chronic pelvic pain syndrome><complement 4-binding protein><complement 4b-binding protein><complementation><cytotoxicity><design><designing><determine efficacy><develop therapy><developmental><efficacy analysis><efficacy assessment><efficacy determination><efficacy evaluation><efficacy examination><efficacy testing><evaluate efficacy><examine efficacy><extrauterine pregnancy><fertility cessation><fertility loss><fitness><flow cytophotometry><gonococcal antibiotic resistance><heavy metal Pb><heavy metal lead><immune drugs><immune evasive><immune therapeutic approach><immune therapeutic interventions><immune therapeutic regimens><immune therapeutic strategy><immune therapy><immune-based therapeutics><immune-based therapies><immune-based treatments><immuno therapy><immunologic therapeutics><immunotherapeutics><immunotherapy agent><improved><in vitro testing><in vivo><infertile><inhibitor><intervention development><intravaginal ring><mouse model><multi-drug resistant><multidrug resistant><murine model><novel><pathway><pore forming protein><porin><pre-clinical development><preclinical development><prevent><preventing><public health priorities><rational design><resistance to anti-microbial><resistant><resistant to antimicrobial><sexually acquired infection><therapeutically effective><therapy development><transmission process><treatment development><trend>