@article {134609, title = {Polyfunctional CD4 T-cells correlating with neutralising antibody is a hallmark of COVISHIELDTM and COVAXIN{\textregistered} induced immunity in COVID-19 exposed Indians.}, journal = {NPJ Vaccines}, volume = {8}, year = {2023}, month = {09/2023}, pages = {134}, abstract = {

Detailed characterisation of immune responses induced by COVID-19 vaccines rolled out in India: COVISHIELDTM (CS) and COVAXIN{\textregistered} (CO) in a pre-exposed population is only recently being discovered. We addressed this issue in subjects who received their primary series of vaccination between November 2021 and January 2022. Both vaccines are capable of strongly boosting Wuhan Spike-specific neutralising antibody, polyfunctional Th1 cytokine producing CD4+ T-cells and single IFN-γ + CD8+ T-cells. Consistent with inherent differences in vaccine platform, the vector-based CS vaccine-induced immunity was of greater magnitude, breadth, targeting Delta and Omicron variants compared to the whole-virion inactivated vaccine CO, with CS vaccinees showing persistent CD8+ T-cells responses until 3 months post primary vaccination. This study provides detailed evidence on the magnitude and quality of CS and CO vaccine induced responses in subjects with pre-existing SARS-CoV-2 immunity in India, thereby mitigating vaccine hesitancy arguments in such a population, which remains a global health challenge.

}, doi = {10.1038/s41541-023-00731-w}, author = {Rakshit, S. and Babji, S. and Parthiban, C. and Madhavan, R. and Adiga, V. and Sharon, Eveline J and Chetan Kumar, N. and Ahmed, A. and Shivalingaiah, S. and Shashikumar, N. and Johnson, A. R. and Mamatha, V. and Ramesh, N. and Goud, B. R. and Asokan, M. and Mayor, S and Kang, G. and D{\textquoteright}souza, G. and Dias, M. and Vyakarnam, A.} } @article {128089, title = {Quantitative fluorescence emission anisotropy microscopy for implementing homo-fluorescence resonance energy transfer measurements in living cells}, journal = {Mol Biol Cell.}, volume = {34}, year = {2023}, month = {05/2023}, abstract = {

Quantitative fluorescence emission anisotropy microscopy reveals the organization of fluorescently labeled cellular components and allows their characterization in terms of changes in either rotational diffusion or homo-F{\"o}rster{\textquoteright}s energy transfer characteristics in living cells. These properties provide insights into molecular organization, such as orientation, confinement, and oligomerization in situ. Here we elucidate how quantitative measurements of anisotropy using multiple microscope systems may be made by bringing out the main parameters that influence the quantification of fluorescence emission anisotropy. We focus on a variety of parameters that contribute to errors associated with the measurement of emission anisotropy in a microscope. These include the requirement for adequate photon counts for the necessary discrimination of anisotropy values, the influence of extinction ratios of the illumination source, the detector system, the role of numerical aperture, and excitation wavelength. All these parameters also affect the ability to capture the dynamic range of emission anisotropy necessary for quantifying its reduction due to homo-FRET and other processes. Finally, we provide easily implementable tests to assess whether homo-FRET is a cause for the observed emission depolarization.

}, doi = {10.1091/mbc.E22-09-0446.}, author = {van Zanten, Thomas and Greeshma, Pradeep S and Mayor, S} } @article {78170, title = {Stratification relieves constraints from steric hindrance in the generation of compact actomyosin asters at the membrane cortex.}, journal = {Sci Adv}, volume = {6}, year = {2020}, month = {03/2020}, abstract = {

Recent in vivo studies reveal that several membrane proteins are driven to form nanoclusters by active contractile flows arising from localized dynamic patterning of F-actin and myosin at the cortex. Since myosin-II assemble as minifilaments with tens of myosin heads, one might worry that steric considerations would obstruct the emergence of nanoclustering. Using coarse-grained, agent-based simulations that account for steric constraints, we find that the patterns exhibited by actomyosin in two dimensions, do not resemble the steady-state patterns in our in vitro reconstitution of actomyosin on a supported bilayer. We perform simulations in a thin rectangular slab, separating the layer of actin filaments from myosin-II minifilaments. This recapitulates the observed features of in vitro patterning. Using super resolution microscopy, we find evidence for such stratification in our in vitro system. Our study suggests that molecular stratification may be an important organizing feature of the cortical cytoskeleton in vivo.

}, doi = {10.1126/sciadv.aay6093}, author = {Das, A and Bhat, A and Sknepnek, R and K{\"o}ster, D and Mayor, S and Rao, M} } @article {60331, title = {C{\textendash}H Arylation of N-Heteroarenes under Metal-Free Conditions and its Application towards the Synthesis of Pentabromo- and Pentachloropseudilins}, journal = {EUROPEAN JOURNAL OF ORGANIC CHEMISTRY}, volume = {2019}, year = {2019}, month = {06/2019}, pages = {3591-3598}, abstract = {

Herein, we have developed a metal-free and mild condition for the synthesis of 2-arylated heteroarenes. The complex forming property and charge transfer property of phenothiazine expanded its application towards catalysis The optimized condition has been successfully employed for the synthesis important marine natural product namely pentabromo/chloropseudilins (PBP/PCP). The synthesized Pentachloropseudilin (PCP) has been shown to phenocopy the effect of Myosin1c depletion which provides a strong justification for the use of PCP as a specific probe for Myosin 1 function in cells.

}, doi = {10.1002/ejoc.201900353}, author = {Kumar, M and Sharma, S and Sil, P and Kushwaha, M and Mayor, S and Vishwakarma, RA and Singh, PP} }