Vaccines against Tuberculosis: Where Are We and Where Do We Need to Go?

In this review we discuss recent progress in the development, testing, and clinical evaluation of new vaccines against tuberculosis (TB). Over the last 20 years, tremendous progress has been made in TB vaccine research and development: from a pipeline virtually empty of new TB candidate vaccines in the early 1990s, to an era in which a dozen novel TB vaccine candidates have been and are being evaluated in human clinical trials. In addition, innovative approaches are being pursued to further improve existing vaccines, as well as discover new ones. Thus, there is good reason for optimism in the field of TB vaccines that it will be possible to develop better vaccines than BCG, which is still the only vaccine available against TB

Genetic variability-, genotype× environment interactions-and combining ability-analyses of kernel tocopherols among maize genotypes possessing novel allele of γ-tocopherol methyl transferase (ZmVTE4)

Not AvailableDeficiency of vitamin-E or tocopherol causes neurological disorders in humans. α-tocopherol possessing the highest vitamin-E activity is present in low concentration in maize kernel. Nine lines and four testers possessing favourable allele of ZmVTE4 that significantly enhances vitamin-E activity were used to generate 36 hybrid combinations. Significant variation was observed for α- (5.95–39.03 μg/g), γ- (11.69–50.82 μg/g), δ- (4.09–10.76 μg/g) and total-tocopherol (33.18–90.53 μg/g). α-, γ- and δ-tocopherol constituted 36%, 53% and 11% of the total tocopherol, respectively. Majority of the experimental hybrids possessed significantly higher α-tocopherol (mean: 21.37 μg/g) than the check hybrids (mean: 11.16 μg/g). AMMI analysis revealed that across tocopherols, genotype and interaction effect accounted 35–77% and 23–45% of variation, respectively. The environmental effects were of minor magnitude. Non-additive gene action was predominant for α-, γ-, and total-tocopherol, while δ-tocopherol was conditioned predominantly by additive gene action. The information generated here assumes great significance in biofortification programme. This is the first report of variability, G × E interactions and combining ability for kernel tocopherol using maize hybrids possessing novel allele of ZmVTE4.Not Availabl

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Not AvailableVitamin-A deficiency is a major health concern. Traditional yellow maize possesses low provitamin-A (proA). Mutant crtRB1 gene significantly enhances proA. 24 experimental hybrids possessing crtRB1 allele were evaluated for β-carotene (BC), β-cryptoxanthin (BCX), lutein (LUT), zeaxanthin (ZEA), total carotenoids (TC) and grain yield at multi-locations. BC (0.64–17.24 µg/g), BCX (0.45–6.84 µg/g), proA (0.86–20.46 µg/g), LUT (9.60–31.03 µg/g), ZEA (1.24–12.73 µg/g) and TC (20.60–64.02 µg/g) showed wide variation. No significant genotype × location interaction was observed for carotenoids. The mean BC (8.61 µg/g), BCX (4.04 µg/g) and proA (10.63 µg/g) in crtRB1-based hybrids was significantly higher than normal hybrids lacking crtRB1-favourable allele (BC: 1.73 µg/g, BCX: 1.29 µg/g and proA: 2.37 µg/g). Selected crtRB1-based hybrids possessed 33% BC and 40% BCX compared to 6% BC and 5% BCX in normal hybrids. BC showed positive correlation with BCX (r = 0.90), proA (r = 0.99) and TC (r = 0.64) among crtRB1-based hybrids. Carotenoids didn't show association with grain yield. Average yield potential of proA rich hybrids (6794 kg/ha) was at par with normal hybrids (6961 kg/ha). PROAH-13, PROAH-21, PROAH-17, PROAH-11, PROAH-23, PROAH-24 and PROAH-3 were the most promising with >12 µg/g proA and >6000 kg/ha grain yield. The newly identified crtRB1-based hybrids assume significance in alleviating malnutrition.Not Availabl

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Not AvailableMalnutrition is a widespread problem that affects human health, society, and the economy. Traditional maize that serves as an important source of human nutrition is deficient in vitamin-E, vitamin-A, lysine, and tryptophan. Here, favorable alleles of vte4 ( -tocopherol methyl transferase), crtRB1 ( -carotene hydroxylase), lcyE (lycopene "-cyclase), and o2 (opaque2) genes were combined in parental lines of four popular hybrids using marker-assisted selection (MAS). BC1F1, BC2F1, and BC2F2 populations were genotyped using gene-based markers of vte4, crtRB1, lcyE, and o2. Background selection using 81–103 simple sequence repeats (SSRs) markers led to the recovery of recurrent parent genome (RPG) up to 95.45%. Alpha (a)-tocopherol was significantly enhanced among introgressed progenies (16.13μg/g) as compared to original inbreds (7.90μg/g). Provitamin-A (proA) (10.42μg/g), lysine (0.352%), and tryptophan (0.086%) were also high in the introgressed progenies. The reconstituted hybrids showed a 2-fold enhancement in a-tocopherol (16.83μg/g) over original hybrids (8.06μg/g). Improved hybrids also possessed high proA (11.48μg/g), lysine (0.367%), and tryptophan (0.084%) when compared with traditional hybrids. The reconstituted hybrids recorded the mean grain yield of 8,066 kg/ha, which was at par with original hybrids (mean: 7,846 kg/ha). The MAS-derived genotypes resembled their corresponding original hybrids for the majority of agronomic and yield-related traits, besides characteristics related to distinctness, uniformity, and stability (DUS). This is the first report for the development of maize with enhanced vitamin-E, vitamin-A, lysine, and tryptophan.Not Availabl