P Frederick Sparling, MD

Sparling, Fred

Clinical Professor

Department of Medicine

8341 Molecular Biomedical Research Bldg, CB# 7031






This laboratory studies the molecular biology of bacterial outer membrane proteins involved in pathogenesis, with a major emphasis on gonococci. A long-term goal is to construct vaccines. The short-term goal is to understand structure, function and regulation of these proteins. For example, recombinant porins are being used to study their vaccine potential.

Genes for iron-repressible receptors for binding human transferrin, lactoferrin, and hemoglobin have been cloned. Each is composed of two proteins, a lipoprotein and an integral outer membrane protein that belongs to the family of TonB dependent proteins. Each is dependent on a functional TonB ExbBD system, and is the product of an iron-regulated operon. A separate system is involved in heme iron utilization. We also have cloned a gonococcal gene for s70kD iron repressible protein (FrpB) that appears important to phenolate siderophore binding. All of these genes appear to be regulated by fur, an iron-dependent repressor.

Function of these iron-receptors is being studied in human volunteers. The transferrin receptor is essential for infectivity of a strain that is a natural lactoferrin-receptor deficient mutant.


Zhu W, Chen CJ, Thomas CE, Anderson JE, Jerse AE, Sparling PF (2011). Vaccines for gonorrhea: can we rise to the challenge? Front Microbiol. 2:124.

Seña AC, White BL, Sparling PF (2010). Novel Treponema pallidum serologic tests: a paradigm shift in syphilis screening for the 21st century. Clin Infect Dis. 51(6):700-8.

Sparling PF (2010). Diagnosis of neurosyphilis: New tools. Sex Transm Dis. 37(5):288-9.

Sparling PF (2006). A vaccine for genital HPV: a time to rejoice! N C Med J. 67(5):384-5.

Thomas CE, Zhu W, Van Dam CN, Davis NL, Johnston RE, Sparling PF (2006). Vaccination of mice with gonococcal TbpB expressed in vivo from Venezuelan equine encephalitis viral replicon particles. Infect Immun. 74(3):1612-20.

Zhu W, Thomas CE, Chen CJ, Van Dam CN, Johnston RE, Davis NL, Sparling PF (2005). Comparison of immune responses to gonococcal PorB delivered as outer membrane vesicles, recombinant protein, or Venezuelan equine encephalitis virus replicon particles. Infect Immun. 73(11):7558-68.

Complete list of publications