Browsing by Author "Rajni Garg"

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Development of a novel multiepitope chimeric vaccine against anthrax
(Springer Verlag, 2019) Somya Aggarwal; Vikas Kumar Somani; Sonal Gupta; Rajni Garg; Rakesh Bhatnagar
Abstract: Bacillus anthracis (BA), the etiological agent of anthrax, secretes protective antigen (PA), lethal factor (LF), and edema factor (EF) as major virulence mediators. Amongst these, PA-based vaccines are most effective for providing immunity against BA, but their low shelf life limits their usage. Previous studies showed that B-cell epitopes, ID II and ID III present in PA domain IV possess higher toxin neutralization activity and elicit higher antibody titer than ID I. Moreover, N-terminal region of both LF and EF harbors PA-binding sites which share 100% identity with each other. Here, in this study, we have developed an epitope-based chimeric vaccine (ID–LFn) comprising ID II–ID III region of PA and N-terminal region of LF. We have also evaluated its protective efficacy as well as stability and found it to be more stable than PA-based vaccine. Binding reactivities of ID–LFn with anti-PA/LF/EF antibodies were determined by ELISA. The stability of chimeric vaccine was assessed using circular dichroism spectroscopy. ID–LFn response was characterized by toxin neutralization, lymphocyte proliferation isotyping and cytokine profiling. The protective efficacy was analyzed by challenging ID–LFn-immunized mice with B. anthracis (pXO1 + and pXO2 + ). ID–LFn was found to be significantly stable as compared to PA. Anti-ID–LFn antibodies recognized PA, LF as well as EF. The T-cell response and the protective efficacy of ID–LFn were found to be almost similar to PA. ID–LFn exhibits equal protective efficacy in mice and possesses more stability as compared to PA along with the capability of recognizing PA, LF and EF at the same time. Thus, it can be considered as an improved vaccine against anthrax with better shelf life. Graphical abstract: [Figure not available: see fulltext.] ID-LFn, a novel multiepitope chimeric anthrax vaccine: ID-LFn comprises of immunodominant epitopes of domain 4 of PA and N-terminal homologous stretch of LF and EF. The administration of this protein as a vaccine provides protection against anthrax. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
Editorial: Understanding the impact of microbes on tumor progression and prevention: unveiling new avenues for cancer therapy
(Frontiers Media SA, 2025) Vikas Kumar Somani; Somya Aggarwal; Rajni Garg; Yoshiko Takeuchi; Samer Singh
[No abstract available]
Importance of cell wall-associated poly-α-l-glutamine in the biology of pathogenic mycobacteria
(Springer Singapore, 2019) Rajni Garg; Rajesh Mani; Manish Gupta; Deeksha Tripathi; Harish Chandra; Rakesh Bhatnagar; Nirupama Banerjee
Mycobacterium tuberculosis (Mtb), the formidable scourge known to mankind since ancient times, has remained untamed despite vigorous scientific research in the field. In the last several decades, significant advances have been made to study this pathogen; however, a lot more remains in the realm of unknown. The complex and unique cell wall of the bacterium is a major factor contributing to the unrestrained success of the pathogen in infecting millions around the world. Since the discovery of this bacterium, numerous studies have attempted to unravel the complexities of mycobacterial cell envelop to characterize individual constituents and their importance in pathobiology of Mtb. Major components of the cell envelop of mycobacteria such as lipid-linked polysaccharides-lipoarabinomannan (LAM), dimycolyl trehalose (cord factor), sulfolipids, and mycolyl-arabinogalactan-peptidoglycan (mAGP) complex have been investigated extensively. However, a lesser known molecule, poly-α-L-glutamine/glutamate (PLG), that constitutes ~10% of dry weight of cell wall has not attracted as much attention. As early as 1990, Hirschfield et al. isolated PLG as insoluble material and showed its association with the Mtb cell wall. In the last few years, our group has been working to identify enzymes that may play a role in the synthesis/assembly and localization of this polymer in the cell wall of mycobacteria. Our recently published work has shown that PLG by itself is weakly immunogenic in mice, but when combined with protein antigens, it can stimulate different arms of the T helper-mediated responses, demonstrating its potential to act as an adjuvant (Mani et al. 2018). © Springer Nature Singapore Pte Ltd. 2019.