Genes of periodontopathogens expressed during human disease.
BACKGROUND
Since many bacterial genes are environmentally regulated, the screening for virulence-associated factors using classical genetic and molecular biology approaches can be biased under laboratory growth conditions of a given pathogen, because the required conditions for expression of many virulence factors may not occur during in vitro growth. Thus, technologies have been developed during the past several years to identify genes that are expressed during disease using animal models of human disease. However, animal models are not always truly representative of human disease, and with many pathogens, there is no appropriate animal model.


METHODS
A new technology, in vivo-induced antigen technology (IVIAT) was thus engineered and tested in our laboratory to screen for genes of pathogenic organisms induced specifically in humans, without the use of animal or artificial models of infection. This technology uses pooled sera from patients to probe for genes expressed exclusively in vivo (or ivi, in vivo-induced genes). IVIAT was originally designed for the study of Actinobacillus actinomycetemcomitans pathogenesis, but we have now extended it to other oral pathogens including Porphyromonas gingivalis.


RESULTS
One hundred seventy-one thousand (171,000) clones from P. gingivalis strain W83 were screened and 144 were confirmed positive. Over 300,000 A. actinomycetemcomitans clones were probed, and 116 were confirmed positive using a quantitative blot assay.


CONCLUSIONS
MAT has proven useful in identifying previously unknown in vivo-induced genes that are likely involved in virulence and are thus excellent candidates for use in diagnostic : and therapeutic strategies, including vaccine design.
Song
Yo-Han
YH
Institute of Oral Bioscience and Department of Oral Microbiology, Chonbuk National University, Chonju, Korea.
Kozarov
Emil V
EV
Walters
Sheila M
SM
Cao
Sam Linsen
SL
Handfield
Martin
M
Hillman
Jeffrey D
JD
Progulske-Fox
Ann
A
D016976:Aggregatibacter actinomycetemcomitans / Q000235:genetics / Q000472:pathogenicity*; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D020869:Gene Expression Profiling / Q000379:methods*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000502:physiology*; D015698:Genomic Library; D006801:Humans; D007158:Immunologic Techniques; D010518:Periodontitis / Q000097:blood / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000096:biosynthesis / Q000235:genetics
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D037521:Virulence Factors