@article {8318, title = {High-quality single amplicon sequencing method for illumina MiSeq platform using pool of {\textquoteright}N{\textquoteright} (0-10) spacer-linked target specific primers without PhiX spike-in [Next Gen Genomics Facility (INT)]}, journal = {BMC Genomics}, volume = {24}, year = {2023}, month = {2023 Mar 23}, pages = {141}, abstract = {

BACKGROUND: Illumina sequencing platform requires base diversity in the initial 11 cycles for efficient cluster identification and colour matrix estimation. This limitation yields low-quality data for amplicon libraries having homogeneous base composition. Spike-in of PhiX library ensures base diversity but reduces the overall number of sequencing reads for data analysis. To overcome such low diversity issues during amplicon sequencing on illumina platforms, we developed a high throughput single amplicon sequencing method by introducing {\textquoteright}N{\textquoteright} (0-10) spacers in target gene amplification primers that are pooled for simple handling.

RESULT: We evaluated the efficiency of {\textquoteright}N{\textquoteright} (0-10) spacer-linked primers by targeting bacterial 16S V3-V4 region, demonstrating heterogeneous base library construction. The addition of {\textquoteright}N{\textquoteright} (0-10) spacers causes sequencing frameshift at every base that leads to base diversity and produces heterogeneous high quality reads within a single amplicon library. We have written a python based command-line software,"MetReTrim", to trim the {\textquoteright}N{\textquoteright} (0-10) spacers from the raw reads ( https://github.com/Mohak91/MetReTrim ). We further demonstrated the accuracy of this method by comparative mock community analysis with standard illumina V3-V4 primer method. The ZymoBIOMICS{\texttrademark} microbial community DNA standard was used as a control for this study. We performed data analysisusing the DADA2 pipeline where taxonomy was assigned using SILVA database as reference. We observed no difference between the communities represented by our method and standard illumina V3-V4 primer method.

CONCLUSION: This method eliminates the need for PhiX spike-in for single amplicon sequencing on illumina MiSeq platform. This allows for sequencing of more number of samples in a run and a reduction in the overall cost. Given that Illumina sequencing works on SBS chemistry irrespective of the platform (such as HiSeq, MiSeq, NextSeq, NovaSeq, etc.) we propose that this strategy of using {\textquoteright}N{\textquoteright} (0-10) spacer-linked primer design can be adopted for generating high-quality single locus amplicon sequencing in a high throughput manner across the illumina platform subject to further validation.

}, keywords = {Bacteria, Gene Library, High-Throughput Nucleotide Sequencing, Microbiota, RNA, Ribosomal, 16S, Sequence Analysis, DNA}, issn = {1471-2164}, doi = {10.1186/s12864-023-09233-4}, author = {Naik, Tejali and Sharda, Mohak and C P, Lakshminarayanan and Virbhadra, Kumar and Pandit, Awadhesh} } @article {3630, title = {Immune profile and responses of a novel dengue DNA vaccine encoding an EDIII-NS1 consensus design based on Indo-African sequences [C-CAMP Bioincubation Facility]}, journal = {Molecular Therapy - Cell Press}, year = {2022}, month = {2022 Jan 07}, type = {Journal Article}, abstract = {

The ongoing COVID-19 pandemic highlights the need to tackle viral variants, expand the number of antigens, and assess diverse delivery systems for vaccines against emerging viruses. In the present study, a DNA vaccine candidate was generated by combining in tandem envelope protein domain III (EDIII) of dengue virus serotypes 1-4 and a dengue virus (DENV)-2 non-structural protein 1 (NS1) protein-coding region. Each domain was designed as a serotype-specific consensus coding sequence derived from different genotypes based on the whole genome sequencing of clinical isolates in\ India and complemented with data from Africa. This sequence was further optimized for protein expression. In silico structural analysis of the EDIII consensus sequence revealed that epitopes are structurally conserved and immunogenic. The vaccination of mice with this construct induced pan-serotype neutralizing antibodies and antigen-specific T\ cell responses. Assaying intracellular interferon (IFN)-γ staining, immunoglobulin IgG2(a/c)/IgG1 ratios, and immune gene profiling suggests a strong Th1-dominant immune\ response. Finally, the passive transfer of immune sera protected AG129 mice challenged with a virulent, non-mouse-adapted DENV-2 strain. Our findings collectively suggest an alternative strategy for dengue vaccine design by offering a novel vaccine candidate with a possible broad-spectrum protection and a successful clinical translation either as a stand alone or in a mix and match strategy.

}, keywords = {antibody-dependent enhancement, consensus sequence, dengue, dengue surveillance, DNA vaccine, EDIII domain, NS1 protein}, issn = {1525-0024}, doi = {10.1016/j.ymthe.2022.01.013}, url = {https://www.cell.com/molecular-therapy-family/molecular-therapy/fulltext/S1525-0016(22)00013-2$\#$secsectitle0165}, author = {Sankaradoss, Arun and Jagtap, Suraj and Nazir, Junaid and Moula, Shefta E and Modak, Ayan and Fialho, Joshuah and Iyer, Meenakshi and Shastri, Jayanthi S and Dias, Mary and Gadepalli, Ravisekhar and Aggarwal, Alisha and Vedpathak, Manoj and Agrawal, Sachee and Pandit, Awadhesh and Nisheetha, Amul and Kumar, Anuj and Bordoloi, Mahasweta and Shafi, Mohamed and Shelar, Bhagyashree and Balachandra, Swathi S and Damodar, Tina and Masika, Moses Muia and Mwaura, Patrick and Anzala, Omu and Muthumani, Kar and Sowdhamini, Ramanathan and Medigeshi, Guruprasad R and Roy, Rahul and Pattabiraman, Chitra and Krishna, Sudhir and Sreekumar, Easwaran} }