| First Author | Jeevan A | Year | 2003 |
| Journal | Infect Immun | Volume | 71 |
| Issue | 1 | Pages | 354-64 |
| PubMed ID | 12496185 | Mgi Jnum | J:80987 |
| Mgi Id | MGI:2447921 | Doi | 10.1128/IAI.71.1.354-364.2003 |
| Citation | Jeevan A, et al. (2003) Differential expression of gamma interferon mRNA induced by attenuated and virulent Mycobacterium tuberculosis in guinea pig cells after Mycobacterium bovis BCG vaccination. Infect Immun 71(1):354-64 |
| abstractText | To determine whether Mycobacterium bovis BCG vaccination would alter gamma interferon (IFN-gamma) mRNA expression in guinea pig cells exposed to Mycobacterium tuberculosis, we cloned a cDNA encoding guinea pig IFN-gamma from a spleen cell cDNA library. The cDNA is composed of 1,110 bp, with an open reading frame encoding a 166-amino-acid protein which shows 56 and 41% amino acid sequence homology to human and mouse IFN-gamma, respectively. Spleen or lymph node cells from naive and BCG-vaccinated guinea pigs were stimulated with purified protein derivative (PPD) or M. tuberculosis H37Ra or H37Rv, and the total RNA was subjected to Northern blot analysis with a (32)P-labeled probe derived from the cDNA clone. Compared to the IFN-gamma mRNA expression in cells of naive animals, that in spleen and lymph node cells exposed to various stimuli was enhanced after BCG vaccination. However, there was a significant reduction in IFN-gamma mRNA levels when cells were stimulated with a multiplicity of infection of greater than 1 virulent M. tuberculosis bacterium per 10 cells. The enhanced IFN-gamma mRNA response in BCG-vaccinated animals was associated with an increase in the proportions of CD4(+) T cells in the spleens, as determined by fluorescence-activated cell sorter analysis. Furthermore, the nonadherent population in the spleens enriched either by panning with anti-guinea pig immunoglobulin G-coated plates or by purification on nylon wool columns produced more IFN-gamma mRNA than whole spleen cells following stimulation with concanavalin A or PPD. This indicates that T cells are principally responsible for the upregulation of IFN-gamma mRNA expression following BCG vaccination. The mechanism by which virulent mycobacteria suppress IFN-gamma mRNA accumulation is currently under investigation. |
