Selection of maize genotypes resistant to pink stem borer and sugarcane borer.

Maize is an important economic crop grown in Nigeria. Its production is dramatically affect by the pink stem borer—Sesamia calamistis (Hampson, Noctuidae) and sugarcane borer—Eldana saccharina (Walker, Pyralidae) that are endemic in Southeastern Nigeria. In areas of stress, existing genotypes may marginally do well due to their inherent capabilities. Therefore, it is possible to find useful genes in such areas of stress, since such genes have been responsible for the survival of host crops over the years. Evaluation study was conducted for a range of agronomic characteristics and resistance attributes for 209 local maize collections from Southeastern Nigeria along with three improved check varieties. Field trials were conducted at three locations in a total of four environments in 2001. Highly significant genotypic variances as were noted in all the traits, are indicative of the magnitude of variation that exists among the genotypes, thus providing the opportunity of selection for desirable traits. Furthermore, four traits, namely, leaf feeding, ear damage, stalk lodging and yield were used from across the environments to construct a rank summation index (RSI), which was used to rank the entries for resistance to stem borers. This RSI led to the identification of 11genotypes which represents the best 5% of the 212 genotypes in resistance ability. Genotype AMA TZBR-WC1 (from International Institute of Tropical Agriculture (IITA), Ibadan) had the best overall resistance levels, followed by genotypes SE NG-77 and SE NG-67 (from Umuahia North), SE NG-62 (from Ikwuano), SE NG-148 (from Ukwa West), SE NG-106 (from Bende), SE NG-119 (from Isiala Ngwa), SE NG-33 (from Ikwuano) and SE NG-65 (from Umuahia North)

Evaluation of thirteen cultivars of Bambara groundnut (Vigna subterranea L. Verdc.) in Umudike, rainforest agroecological area of Nigeria.

A field experiment was conducted in the 1999 and repeated in 2000 cropping season at the Michael Okpara University of Agriculture, Umudike to evaluate the agronomic and yield attributes of thirteen cultivars of bambara groundnut for use in crop improvement programme. The accessions collected from Enugu state were studied in randomized complete block experiment with three replications. Data were collected on plant height, number of leaves per plant, leaf area per plant, leaf area index (LAI), days to 50% flowering, number of flowers per plant, grain filling period, crop duration, number of pods per plant, number of seeds per plant, 100-seed weight and grain yield per hectare. The results obtained in 1999 did not differ significantly from that in 2000. The significant differences (

Rapid profiling of RSV antibody repertoires from the memory B cells of naturally infected adult donors

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in young children and the elderly. There are currently no licensed RSV vaccines, and passive prophylaxis with the monoclonal antibody palivizumab is restricted to high-risk infants in part due to its modest efficacy. Although it is widely agreed that an effective RSV vaccine will require the induction of a potent neutralizing antibody response against the RSV fusion (F) glycoprotein, little is known about the specificities and functional activities of RSV F-specific antibodies induced by natural infection. Here, we have comprehensively profiled the human antibody response to RSV F by isolating and characterizing 364 RSV F-specific monoclonal antibodies from the memory B cells of three healthy adult donors. In all donors, the antibody response to RSV F is comprised of a broad diversity of clones that target several antigenic sites. Nearly half of the most potent antibodies target a previously undefined site of vulnerability near the apex of the prefusion conformation of RSV F (preF), providing strong support for the development of RSV vaccine candidates that preserve the membrane-distal hemisphere of the preF protein. Additionally, the antibodies targeting this new site display convergent sequence features, thus providing a future means to rapidly detect the presence of these antibodies in human vaccine samples. Many of the antibodies that bind preF-specific surfaces are over 100 times more potent than palivizumab, and several cross-neutralize human metapneumovirus (HMPV). Taken together, the results have implications for the design and evaluation of RSV vaccine candidates and offer new options for passive prophylaxis.We thank Tushar Jain for guidance on statistical analyses, Todd Boland for assistance with antibody sequence analysis, Emilie Shipman for assistance with protein expression, Wen Li for technical assistance, Cody Williams and S.M. Eagol for assistance with figure preparation, and Margaret Ackerman for use of the magnetic microplate washer (BioTek) and the FLEXMAP 3D flow cytometer (Luminex). PBMC processing was carried out in DartLab, the Immune Monitoring and Flow Cytometry Shared Resource, supported by a National Cancer Institute Cancer Center Support Grant to the Norris Cotton Cancer Center (P30CA023108-37) and an Immunology COBRE Grant (P30GM103415-15) from the National Institute of General Medical Sciences. All the IgGs were sequenced by Adimab's Molecular Core and produced by the High Throughput Expression group. Biolayer interferometry binding experiments were performed by Adimab's protein analytics group. Funding: Support for this work was provided by the National Institute of General Medical Sciences of the National Institutes of Health award T32GM008704 (M.S.A.G.) and P20GM113132 (J.S.M.) and intramural funding from the National Institute of Allergy and Infectious Diseases to support work at the Vaccine Research Center (B.S.G.). This work was partially supported by grant SAF2015-67033-R to J.A.M. from Plan Nacional I+D+i.S

Absence of Association between Cord Specific Antibody Levels and Severe Respiratory Syncytial Virus (RSV) Disease in Early Infants: A Case Control Study from Coastal Kenya

The target group for severe respiratory syncytial virus (RSV) disease prevention is infants under 6 months of age. Vaccine boosting of antibody titres in pregnant mothers could protect these young infants from severe respiratory syncytial virus (RSV) associated disease. Quantifying protective levels of RSV-specific maternal antibody at birth would inform vaccine development. METHODS: A case control study nested in a birth cohort (2002–07) was conducted in Kilifi, Kenya; where 30 hospitalised cases of RSV-associated severe disease were matched to 60 controls. Participants had a cord blood and 2 subsequent 3-monthly blood samples assayed for RSV-specific neutralising antibody by the plaque reduction neutralisation test (PRNT). Two sample paired t test and conditional logistic regression were used in analyses of log2PRNT titres. RESULTS: The mean RSV log2PRNT titre at birth for cases and controls were not significantly different (P = 0.4) and remained so on age-stratification. Cord blood PRNT titres showed considerable overlap between cases and controls. The odds of RSV disease decreased with increase in log2PRNT cord blood titre. There was a 30% reduction in RSV disease per unit increase in log2PRNT titre (<3months age group) but not significant (P = 0.3). CONCLUSIONS: From this study, there is no strong evidence of protection by maternal RSV specific antibodies from severe RSV disease. Cord antibody levels show wide variation with considerable overlap between cases and controls. It is likely that, there are additional factors to specific PRNT antibody levels which determine susceptibility to severe RSV disease. In addition, higher levels of neutralizing antibody beyond the normal range may be required for protection; which it is hoped can be achieved by a maternal RSV vaccine

Breast Milk Prefusion F Immunoglobulin G as a Correlate of Protection Against Respiratory Syncytial Virus Acute Respiratory Illness

Background: Transplacental respiratory syncytial virus (RSV) antibody transfer has been characterized, but little is known about the protective effect of breast milk RSV-specific antibodies. Serum antibodies against the prefusion RSV fusion protein (pre-F) exhibit high neutralizing activity. We investigate protection of breast milk pre-F antibodies against RSV acute respiratory infection (ARI). Methods: Breast milk at 1, 3, and 6 months postpartum and midnasal swabs during infant illness episodes were collected in mother-infant pairs in Nepal. One hundred seventy-four infants with and without RSV ARI were matched 1:1 by risk factors for RSV ARI. Pre-F immunoglobulin A (IgA) and immunoglobulin G (IgG) antibody levels were measured in breast milk. Results: The median breast milk pre-F IgG antibody concentration before illness was lower in mothers of infants with RSV ARI (1.4 [interquartile range {IQR}, 1.1-1.6] log10 ng/mL) than without RSV ARI (1.5 [IQR, 1.3-1.8] log10 ng/mL) (P = .001). There was no difference in median maternal pre-F IgA antibody concentrations in cases vs controls (1.7 [IQR, 0.0-2.2] log10 ng/mL vs 1.7 [IQR, 1.2-2.2] log10 ng/mL, respectively; P = .58). Conclusions: Low breast milk pre-F IgG antibodies before RSV ARI support a potential role for pre-F IgG as a correlate of protection against RSV ARI. Induction of breast milk pre-F IgG may be a mechanism of protection for maternal RSV vaccines