Neisseria gonorrhoeae pilus attenuates cytokine response of human fallopian tube explants.
BACKGROUND
A role for pilus during attachment of Neisseria gonorrhoeae to epithelia of the female reproductive tract is currently assumed. However, Pil⁻ gonococci have been observed during infection of the reproductive tract, which prompted us to examine the effect of pili on the dynamics of infection and the inflammatory responses of mucosal explants of the human fallopian tube.


METHODS
Mucosal explants were infected in vitro with Opa negative Pil⁻ and Pil⁺N. gonorrhoeae strains.


RESULTS
Piliation enhanced gonococcal adherence to the epithelium within 3 h of infection (P < 0.05) but thereafter did not offer advantage to gonococci to colonize the epithelial cell surface (P > 0.05). No differences were found between the strains in numbers of gonococci inside epithelial cells. Pil⁻ bacteria induced higher levels (P < 0.05) of IL-1β, TNF-α, GM-CSF, MCP-1, and MIP-1β than Pil⁺ bacteria. There were no differences between both strains in LOS pattern, and Pil expression did not change after coincubation with mucosal strips.


CONCLUSIONS
Results show that gonococcal invasion of the human fallopian tube can occur independently of pilus or Opa expression, and suggest that pilus, by inhibition of several key elements of the initial inflammatory response, facilitates sustained infection of this organ.
Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40 Correo 33, 9170022 Santiago, Chile.
Luis
L
Velasquez
Katherine
K
García
Francisco
F
Morales
John E
JE
Heckels
Pedro
P
Orihuela
Paula I
PI
Rodas
Myron
M
Christodoulides
Hugo
H
Cardenas
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004848:Epithelium / Q000382:microbiology*; D005187:Fallopian Tubes / Q000382:microbiology*; D005260:Female; D010861:Fimbriae, Bacterial / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000382:microbiology; D009344:Neisseria gonorrhoeae / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D009924:Organ Culture Techniques
D001425:Bacterial Outer Membrane Proteins; D016207:Cytokines; C090348:Opa protein, Neisseria