RESUMO
Lead (Pb) is a typical toxic contamination source all over the world. In this research, larvae of the housefly (Musca domestica) were fed a Pb-contaminated diet at different Pb doses of 0, 20 and 5000 mg/kg. RNA sequencing was used to identify genes that were differentially expressed in relation to lead transport or detoxification. RNA interference (RNAi) was carried on 12 candidate genes. The results showed that three luminal pH regions of mid-gut were at pH values of 6.33, 3.10, and 7.80. With increasing Pb concentration, the pH of the middle mid-gut decreased by one unit. The expression levels of carboxypeptidase A (CPA1), glutathione S-transferase (GST), and cytochrome b (Cyt b) were linked to Pb treatments, particularly high Pb concentration of 5000 mg/kg. RNAi-mediated down expression of CPA1, GST2, and CYTb-c1 resulted in low Pb accumulation in the larvae of 5000 mg/kg Pb group. These proteins played key roles in Pb transport and detoxification in M. domestica larvae.
RESUMO
Comparative tracking of tetramer-positive and epitope-specific CD4(+) T cells in blood and other tissues from tuberculosis (TB) patients during TB development and treatment using control donor samples is not well characterized. In this study, a novel HLA-DR-restricted peptide E7 from the ESAT-6 protein of Mycobacterium tuberculosis (MTB) was used to prepare modified HLA-DR*08032/E7 tetramer (tetramer 1) and HLA-DR*0818/E7 tetramer (tetramer 2) to monitor a series of samples from TB patients and control donors. Tetramer staining showed that (1) by direct staining of single sample and flow cytometric analyses, detection of tetramer-positive CD4(+) T cells ranged from 0.1% to 8.8% (median 0.67% in tetramer 1 and 0.5% in tetramer 2), 0.1 to 10.7% (0.74% and 0.71%), 0.02 to 2.2% (0.25% and 0.25%), 0.02 to 0.48% (0.2% and 0.2%) and most at under 0-0.2% (0.2% and 0.16%) in the initial pulmonary TB (PTB) patients' blood, pleural fluid (PLF) of initial tuberculous pleuritis patients, non-TB patients' blood, healthy donors' blood and umbilical cord blood, respectively; significantly higher levels of CD4(+) T cells were detected in samples of TB patients than in three control donor groups; (2) by direct staining of time point TB samples and flow cytometric analyses, along with TB symptom amendment at day 60, tetramer-positive CD4(+) T cells began to decrease, until after 90-120 days, reached and kept at a relatively low even normal level about at 0.03-0.3%; (3) by enrichment approach, at least 10-fold increased memory tetramer-positive CD4(+) T cells were seen; (4) by in situ staining, tetramer-positive, IFN-γ-producing and/or TNF-α-producing CD4(+) T cells in the lymph node and lung granuloma and cavernous tissues of TB patients could be determined. Therefore, by further increasing the sample size tested to confirm the specificity and sensitivity of tetrameric molecules, it should be possible to develop them for use as research and diagnostic reagents.