Biology subjects

Laha, E.

Publications and source records attributed to Laha, E..

3 recordsLinked to original sources

bioRxiv2022

DNA damage response signaling is crucial for effective Chikungunya virus replication

Viruses utilize a plethora of strategies to manipulate the host pathways and hijack its machineries for efficient replication. Several DNA as well as handful of RNA viruses are reported to interact with proteins involved in DNA damage responses (DDR). As the DDR pathways have never been explored in Alphaviruses, this investigation intended to determine the importance of the DDR pathways in CHIKV infection through in vitro, in vivo and ex vivo models. The study reveals that CHIKV infection activates the Chk2 and Chk1 proteins associated with DDR signaling pathways and increases DNA damage by 95%. Inhibition of both ATM-ATR kinases by ATM/ATR kinase inhibitor (AAKi) shows drastic reduction in viral particle formation in vitro. Next, the treatment of mice with this drug has been shown to reduce the disease score substantially in CHIKV-infected C57BL/6 mice with 71% decrement in the viral copy and the same has been established in hPBMC-derived monocyte-macrophage populations. Additionally, gene silencing of Chk2 and Chk1 reduces viral progeny formation around 73.7% and 78% respectively. Moreover, it has been demonstrated that CHIKV-nsP2 interacts with Chk2 and Chk1 during CHIKV infection and docking analysis depicts the specific amino acids responsible for these interactions. Further, the data suggests that CHIKV infection induces cell cycle arrest in G1 and G2 phases. In conclusion, this work demonstrated for the first time the mechanistic insight of the induction of DDR pathways by CHIKV that might contribute to the designing of effective therapeutics for the control of this virus infection in future. IMPORTANCEViruses being intra-cellular parasite, need several host cell machineries so as to achieve effective replication of their own genome, along with virus-encoded enzymes. One of the strategies is to hijack the DDR pathways. Several DNA as well as handful of RNA viruses interact with the cellular proteins involved in DDR pathways, however, reports with respect to the association of Chk2 and Chk1 in alphavirus infection are scanty. Hence, this study is amongst the first to report that modulation of DDR pathways is crucial for effective CHIKV infection. This work also shows that there is interaction of CHIKV-nsP2 with two crucial host factors, Chk2 and Chk1 for efficient viral infection. Interestingly, CHIKV infection was found to cause DNA damage and arrest cell cycle in G1 and G2 phases to facilitate viral infection. This information might facilitate to develop effective therapeutics for the control of the CHIKV infection in future.

microbiology↗

bioRxiv2021

Telmisartan restricts Chikungunya virus infection in vitro and in vivo through the AT1/ PPAR-γ/MAPKs pathways

Chikungunya virus (CHIKV) has re-emerged as a global public health threat. The inflammatory pathways of RAS and PPAR-{gamma} are usually involved in viral infections. Thus, Telmisartan (TM) with known capacity to block AT1 receptor and activate PPAR-{gamma}, was investigated against CHIKV. The anti-CHIKV effect of TM was investigated in vitro (Vero, RAW 264.7 cells and hPBMCs) and in vivo (C57BL/6 mice). TM was found to abrogate CHIKV infection efficiently (IC50 of 15.34-20.89{micro}M in the Vero and RAW 264.7 cells respectively). Viral RNA and proteins were reduced remarkably with the TM driven modulation of host m-TOR signaling. Additionally, TM interfered in the early and late stages of CHIKV life cycle with efficacy in both pre and post-treatment assay. Moreover, the agonist of AT1 receptor and antagonist of PPAR-{gamma} increased CHIKV infection suggesting TMs anti-viral potential by modulating host factors. Besides, reduced activation of all major MAPKs, NF-{kappa}B (p65) and cytokines by TM through the inflammatory axis supported the fact that the anti-CHIKV efficacy of TM is partly mediated through the AT1/PPAR-{gamma}/MAPKs pathways. Interestingly, at the human equivalent dose, TM abrogated CHIKV infection and inflammation significantly leading to reduced clinical score and complete survival of C57BL/6 mice. Additionally, TM reduced infection in hPBMC derived monocyte-macrophage populations in vitro. Hence, TM was found to reduce CHIKV infection by targeting both viral and host factors. Considering its safety and in vivo efficacy, it can be a suitable candidate in future for repurposing against CHIKV.

microbiology↗

bioRxiv2021

MK2a inhibitor CMPD1 abrogates chikungunya virus infection by modulating actin remodeling pathway

Chikungunya virus (CHIKV) epidemics around the world have created public health concern with the unavailability of effective drugs and vaccines. This emphasizes the need for molecular understanding of host-virus interactions for developing effective targeted antivirals. Microarray analysis was carried out using CHIKV strain (Prototype and Indian) infected Vero cells and two host isozymes, MK2 and MK3 were selected for further analysis. Gene silencing and drug treatment were performed in vitro and in vivo to unravel the role of MK2/MK3 in CHIKV infection. Gene silencing of MK2 and MK3 abrogated around 58% CHIKV progeny release from the host cell and a MK2 activation (a) inhibitor (CMPD1) treatment demonstrated 68% inhibition of viral infection suggesting a major role of MAPKAPKs during the late phase of CHIKV infection in vitro. Further, it was observed that the inhibition in viral infection is primarily due to the abrogation of lamellipodium formation through modulation of factors involved in the actin cytoskeleton remodeling pathway that is responsible for releasing the virus from the infected cells. Moreover, CHIKV-infected C57BL/6 mice demonstrated reduction in the viral copy number, lessened disease score and better survivability after CMPD1 treatment. In addition, reduction in expression of key pro-inflammatory mediators such as CXCL13, RAGE, FGF, MMP9 and increase in HGF (a CHIKV infection recovery marker) was observed indicating the effectiveness of this drug against CHIKV. Additionally, CMPD1 also inhibited HSV1 and SARS CoV2-19 infection in vitro. Taken together it can be proposed that MK2 and MK3 are crucial host factors for CHIKV infection and can be considered as key targets for developing effective anti-CHIKV strategies in future. Author summaryChikungunya virus has been a dreaded disease from the first time it occurred in 1952 Tanzania. Since then it has been affecting the different parts of the world at different time periods in large scale. It is typically transmitted to humans by bites of Aedes aegypti and Aedes albopictus mosquitoes. Although, studies have been undertaken to combat the disease still there are no effective strategies like vaccines or antivirals against it. Therefore it is essential to understand the virus and host interaction to overcome this hurdle. In this study two host factors MK2 and MK3 have been taken into consideration to see how they regulate the multiplication of the virus. The in vitro experiments demonstrated that inhibition of MK2 and MK3 restricted viral infection Further, it was observed that this is due to the blocking of lamellipodium formation by modifying the factors involved in the actin cytoskeleton remodeling pathway that is responsible for releasing the virus from the infected cells. Besides, decreased disease score as well as better survivability was noticed in the in vivo experiments with mice. Therefore, MK2 and MK3 could be considered as the key targets for controlling CHIKV infection.

microbiology↗