@article {6585, title = {Base editing of key residues in the BCL11A-XL-specific zinc finger domains derepresses fetal globin expression.}, journal = {Mol Ther}, volume = {32}, year = {2024}, month = {2024 Mar 06}, pages = {663-677}, abstract = {

BCL11A-XL directly binds and represses the fetal globin (HBG1/2) gene promoters, using 3 zinc-finger domains (ZnF4, ZnF5, and ZnF6), and is a potential target for β-hemoglobinopathy treatments. Disrupting BCL11A-XL results in derepression of fetal globin and high HbF, but also affects hematopoietic stem and progenitor cell (HSPC) engraftment and erythroid maturation. Intriguingly, neurodevelopmental patients with ZnF domain mutations have elevated HbF with normal hematological parameters. Inspired by this natural phenomenon, we used both CRISPR-Cas9 and base editing at specific ZnF domains and assessed the impacts on HbF production and hematopoietic differentiation. Generating indels in the various ZnF domains by CRISPR-Cas9 prevented the binding of BCL11A-XL to its site in the HBG1/2 promoters and elevated the HbF levels but affected normal hematopoiesis. Far fewer side effects were observed with base editing- for instance, erythroid maturation in\ vitro was near normal. However, we observed a modest reduction in HSPC engraftment and a complete loss of B cell development in\ vivo, presumably because current base editing is not capable of precisely recapitulating the mutations found in patients with BCL11A-XL-associated neurodevelopment disorders. Overall, our results reveal that disrupting different ZnF domains has different effects. Disrupting ZnF4 elevated HbF levels significantly while leaving many other erythroid target genes unaffected, and interestingly, disrupting ZnF6 also elevated HbF levels, which was unexpected because this region does not directly interact with the HBG1/2 promoters. This first structure/function analysis of ZnF4-6 provides important insights into the domains of BCL11A-XL that are required to repress fetal globin expression and provide framework for exploring the introduction of natural mutations that may enable the derepression of single gene while leaving other functions unaffected.

}, keywords = {Fetal Hemoglobin, gamma-Globins, Gene Editing, Hematopoietic Stem Cells, Humans, Repressor Proteins, Zinc Fingers}, issn = {1525-0024}, doi = {10.1016/j.ymthe.2024.01.023}, author = {Rajendiran, Vignesh and Devaraju, Nivedhitha and Haddad, Mahdi and Ravi, Nithin Sam and Panigrahi, Lokesh and Paul, Joshua and Gopalakrishnan, Chandrasekar and Wyman, Stacia and Ariudainambi, Keerthiga and Mahalingam, Gokulnath and Periyasami, Yogapriya and Prasad, Kirti and George, Anila and Sukumaran, Dhiyaneshwaran and Gopinathan, Sandhiya and Pai, Aswin Anand and Nakamura, Yukio and Balasubramanian, Poonkuzhali and Ramalingam, Rajasekaran and Thangavel, Saravanabhavan and Velayudhan, Shaji R and Corn, Jacon E and Mackay, Joel P and Marepally, Srujan and Srivastava, Alok and Crossley, Merlin and Mohankumar, Kumarasamypet M} } @article {6593, title = {SMART-lipid nanoparticles enabled mRNA vaccine elicits cross-reactive humoral responses against the omicron sub-variants.}, journal = {Mol Ther}, year = {2024}, month = {2024 Feb 27}, abstract = {

The continual emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has necessitated the development of broad cross-reactive vaccines. Recent findings suggest that enhanced antigen presentation could lead to cross-reactive humoral responses against the emerging variants. Toward enhancing the antigen presentation to dendritic cells (DCs), we developed a novel shikimoylated mannose receptor targeting lipid nanoparticle (SMART-LNP) system that could effectively deliver mRNAs into DCs. To improve the translation of mRNA, we developed spike domain-based trimeric S1 (TS1) mRNA with optimized codon sequence, base modification, and engineered 5{\textquoteright} and 3{\textquoteright} UTRs. In a mouse model, SMART-LNP-TS1 vaccine could elicit robust broad cross-reactive IgGs against Omicron sub-variants, and induced interferon-γ-producing T\ cells against SARS-CoV-2 virus compared with non-targeted LNP-TS1 vaccine. Further, T\ cells analysis revealed that SMART-LNP-TS1 vaccine induced long-lived memory T\ cell subsets, T helper 1 (Th1)-dominant and cytotoxic T\ cells immune responses against the SARS-CoV-2 virus. Importantly, SMART-LNP-TS1 vaccine produced strong Th1-predominant humoral and cellular immune responses. Overall, SMART-LNPs can be explored for precise antigenic mRNA delivery and robust immune responses. This platform technology can be explored further as a next-generation delivery system for mRNA-based immune therapies.

}, issn = {1525-0024}, doi = {10.1016/j.ymthe.2024.02.028}, author = {Mahalingam, Gokulnath and Rachamalla, Hari Krishnareddy and Arjunan, Porkizhi and Karuppusamy, Karthik V and Periyasami, Yogapriya and Mohan, Aruna and Subramaniyam, Kanimozhi and M, Salma and Rajendran, Vigneshwar and Moorthy, Mahesh and Varghese, George M and Mohankumar, Kumarasamypet M and Thangavel, Saravanabhavan and Srivastava, Alok and Marepally, Srujan} } @article {3716, title = {Omicron infection increases IgG binding to spike protein of predecessor variants.}, journal = {J Med Virol}, year = {2022}, month = {2022 Dec 22}, abstract = {

BACKGROUND: SARS-CoV-2 transmission in India in 2020-2022 was driven predominantly by Wild (Wuhan-Hu-1and D614G), Delta, and Omicron variants. The aim of this study was to examine the effect of infections on the humoral immune response and cross-reactivity to spike proteins of Wuhan-Hu-1, Delta, C.1.2., and Omicron.

OBJECTIVES: Residual archival sera (N=81) received between January 2020 and March 2022 were included. Infection status was inferred by a positive SARS-CoV-2 RT-PCR and/or serology (anti-N and anti-S antibodies) and sequencing of contemporaneous samples (N=18) to infer lineage. We estimated the levels and cross-reactivity of infection-induced sera including Wild, Delta, Omicron as well as vaccine breakthrough infections (Delta and Omicron).

RESULTS: We found ~2-fold increase in spike-specific IgG antibody binding in post-Omicron infection compared to the pre-Omicron period, whilst the change in pre- and post-Delta infections were similar. Further investigation of Omicron-specific humoral responses revealed primary Omicron infection as an inducer of cross-reactive antibodies against predecessor variants, in spite of weaker degree of humoral response compared to Wuhan-Hu-1 and Delta infection. Intriguingly, Omicron vaccine-breakthrough infections when compared with primary infections, exhibited increased humoral responses against RBD (7.7-fold) and Trimeric S (Trimeric form of spike protein) (34.6-fold) in addition to increased binding of IgGs towards previously circulating variants (4.2 - 6.5-fold). Despite Delta breakthrough infections showing a higher level of humoral response against RBD (2.9-fold) and Trimeric S (5.7-fold) compared to primary Delta sera, a demonstrably reduced binding (36-49\%) was observed to Omicron spike protein.

CONCLUSIONS: Omicron vaccine breakthrough infection results in increased intensity of humoral response and wider breadth of IgG binding to spike proteins of antigenically-distinct, predecessor variants. This article is protected by copyright. All rights reserved.

}, issn = {1096-9071}, doi = {10.1002/jmv.28419}, author = {Mahalingam, Gokulnath and Periyasami, Yogapriya and Arjunan, Porkizhi and Subaschandrabose, Rajesh Kumar and Mathivanan, Tamil Venthan and Mathew, Roshlin Susan and Ramya Devi, Kt and Premkumar, Prasanna Samuel and Muliyil, Jayaprakash and Srivastava, Alok and Moorthy, Mahesh and Marepally, Srujan} }