Cloning of a Mycobacterium tuberculosis gene encoding a purifed protein derivative protein that elicits strong tuberculosis-specific delayed-type hypersensitivity
Rn. Coler et al., Cloning of a Mycobacterium tuberculosis gene encoding a purifed protein derivative protein that elicits strong tuberculosis-specific delayed-type hypersensitivity, J INFEC DIS, 182(1), 2000, pp. 224-233
The purified protein derivative (PPD) skin test has been used for the diagn
osis of tuberculosis for more than 75 years. However, the test lacks specif
icity because all mycobacteria share antigens present in PPD, Therefore, se
nsitization with nontuberculous pathogenic or with environmental nonpathoge
nic mycobacteria can lead to positive skin tests. This communication descri
bes a novel PPD protein present only in tuberculous complex mycobacteria, A
recombinant protein was obtained and named DPPD on the basis of the first
4 amino acids of its N-terminus sequence, DPPD elicited delayed-type hypers
ensitivity (DTH) in 100% of Mycobacterium tuberculosis-infected guinea pigs
but in no animals sensitized with several organisms representative of all
members of the Mycobacterium genus. Preliminary results indicate that DPPD
induces strong and specific DTH in humans. This work points to the definiti
on of a single recombinant M, tuberculosis protein that may be an alternati
ve to the PPD test.