MT-4 Cells Research Articles

Evaluation of anti-HIV-1 (Retroviridae: Orthoretrovirinae: Lentivirus: Human immunodeficiency virus type 1) activity of 6HP and 3TC in vitro using MT-4 cell line variants with different replicative activity.

Chemotherapy of HIV infection remains the only means of treating the disease. The process of development new and improving previously developed drugs is therefore considered a priority. One of the preclinical stage of drug efficacy testing is research in the virus-cell model system in vitro. To evaluate the antiviral efficacy of nucleoside reverse transcriptase inhibitors (NRTIs) 6HP and 3TC during HIV-1 replication in the neoplastic MT-4 cell line. Two variants of the CD4+ T-lymphocyte MT-4 cell line (MT-4/1 and MT-4/2) transformed by Human T-lymphotropic virus type 1 (Retroviridae: Orthoretrovirinae: Deltaretrovirus: HTLV-1), with different levels of HIV-1 replication were used. Drugs ammonium-3'-azido-3'-deoxythymidine-5'-carbomoylphosphonat (6HP) and 2',3'-dideoxy-3'-thiacytidine (3TC) were used to suppress the virus. The replication activity of HIV-1 was observed to be higher in the MT-4/2 line than in the MT-4/1 line for different strains of the virus. The use of each of the substances separately showed a more significant inhibition of viral activity in MT-4/1 than in MT-4/2 cells. When used together, the inhibition level was almost the same in all cases and ranged from 87‒96% for the MT-4/1 line and 83‒89% for the MT-4/2 line. High efficacy was observed when using lower concentrations of drugs compared to individual use. The combined use of NRTIs 6НР and 3TС is promising for the treatment of HIV-infected patients at different stages of infection and with different levels of viral load.

CRISPR/Cas9 mediated CHS2 mutation provides a new insight into resveratrol biosynthesis by causing a metabolic pathway shift from flavonoids to stilbenoids in Vitis davidii cells

Abstract Resveratrol is an important phytoalexin that adapts to and responds to stressful conditions, plays various roles in health and medical therapies. However, it is only found in a limited number of plant species in low concentrations, which hinders its development and utilization. Chalcone synthase (CHS) and stilbene synthase (STS) catalyze the same substrates to produce flavonoids and resveratrol, respectively. However, it remains unclear how CHS and STS compete in metabolite synthesis. In this study, two CHS2 mutant cell lines (MT1 and MT2) were generated using CRISPR/Cas9 genome editing. These CHS2 mutant cell lines exhibited abundant mutations in CHS2, leading to the premature termination of protein translation and subsequent CHS2 knockout. Amplicon sequencing confirmed comprehensive CHS2 knockout in MT1, whereas the wild-type sequence remained predominant in the MT2 cell line. Transcriptome and RT-qPCR results showed a significant downregulation of genes involved in flavonoid biosynthesis, including CHS2, CHS3, F3H, F3’H, DFR, FLS, LDOX, among others, resulting in decreased flavonoid accumulation, such as anthocyanins, proanthocyanidins, quercetin, and kaempferol. Conversely, STS genes involved in stilbenoid biosynthesis were upregulated competing with the flavonoid pathway. Consequently, there was a marked increase in stilbenoids, including resveratrol, piceatannol, piceid and pterostilbene, with a 4.1-fold increase in resveratrol and a 5.3-fold increase in piceid (a derivative of resveratrol) observed in CHS2 mutant cell lines. This research demonstrates that CHS2 mutation induces a shift from flavonoid biosynthesis towards stilbenoid biosynthesis, offering new insights into metabolite biosynthesis and regulation, as well as an alternative solution for natural resveratrol production, and a novel breeding approach for eliminating non-target agronomic traits using CRISPR-Cas9.

CRISPR/Cas9-mediated RELA and RELC knockout in human regulatory T cells abrogates FOXP3 expression and suppressive function

Mutations in NF-κB-related molecules result in combined immunodeficiency characterized by recurrent infection. In this study, we aimed to investigate the association between mutations in NF-κB family members, RELA, RELB, and RELC, and regulatory T cell (Treg) function in humans. RELA, RELB, and RELC were knocked out using CRISPR/Cas9-mediated homologous recombination in CD4+/CD8+ T cells and Tregs isolated from healthy donors. The RELA, RELB, and RELC knockouts did not alter the phenotype or cytokine production profile of CD4+/CD8+ T cells or Jurkat cells. Similar to that observed in knockout mice, RELA or RELC knockout in MT-2 cells and freshly isolated Tregs reduced FOXP3 expression and the immune suppressive function of Tregs. Additionally, PD-L1 expression in effector T cells and Tregs decreased considerably following RELC knockdown. These findings demonstrated that the deletion of RELA or RELC resulted in the loss of Treg-like phenotype and function owing to the downregulation of FOXP3 expression.

Developing new drugs for adult T-cell leukemia/lymphoma by targeting hypoxia: insights from toxicity of MS-275 and its analogs

The low survival rate of adult T-cell leukemia/lymphoma (ATL) underscores the critical need for innovative therapeutic agents. While the pharmacokinetics of HDACis have been documented in several hematological neoplasms, there is a notable gap in research regarding their activity against ATL. Given that hypoxia can induce unpredictable effects on lymphoma cells, this study aimed to evaluate the toxic effects of MS-275 and novel analogs on ATL cells in hypoxic condition for the first time. Protein-protein interaction and gene set enrichment analyses were performed, the expression of HIF1A and downstream targets were assessed, and molecular docking was conducted on MS-275 and novel analogs with HIF-1α. For in vitro studies, at first benzamide analogs of MS-275 were synthesized and then, viability of MT-2 cells was evaluated in hypoxic condition. Enrichment analyses confirmed the involvement of hub genes in HIF-1 signaling pathway and volcano plot revealed over expression of HIF1A, GAL3ST1 and CD274. Molecular docking indicated favorable interaction between MS-275 and analogs with HIF-1α PAS-B domain. Results of alamarBlue assay demonstrated that MS-275 and analogs significantly (p < 0.001) reduced viability of MT-2 cells in hypoxic condition. Findings of the present study hold promise for developing new drugs targeting hypoxia-induced changes in ATL.

The effect of sodium deoxyribonucleate with iron complex on the expression of surface markers of MT-4 cells infected with human immunodeficiency virus type 1 (HIV-1) (Retroviridae: Primate lentivirus group)

The persistence of immune dysfunction during therapy has serious consequences for the health of HIV-infected people. Therefore, an important direction is the search for drugs that can reduce the inflammatory potential of the immune system and serve as an additional component of antiviral therapy. Aim ‒ to study the effect of the immunomodulatory drug Sodium deoxyribonucleate with iron complex (DNA-Na-Fe) on the expression of activation markers in MT-4 cells infected with HIV-1. Expression levels of CD4, CD28, CD38, CD62L and HLA-DR proteins on the plasma membrane were measured in cells. To assess viral activity, the p24 protein was quantified by ELISA. The two cell variants with different replicative activity were analyzed. Control cells, cells with DNA-Na-Fe, infected cells and infected cells with DNA-Na-Fe were tested. Based on the results obtained, it can be concluded that antiviral activity of the drug in MT-4 cells infected with HIV-1 is associated with immunomodulatory activity that enhances the expression of membrane proteins CD4, CD28, CD38 and CD62L. Diversity in the effect of DNA-Na-Fe on the studied surface proteins expression in two cell lines indicates that they depend on the characteristics of the combined molecular biological processes occurring in cells. And the increased effects observed in a system with changes in replicative activity assumes its active participation in virus replication at the stages of virus penetration and budding. Studies have shown that DNA-Na-Fe has antiviral and immunomodulatory activity.

Screening of promising chemotherapeutic candidates from plants against human adult T-cell leukaemia/lymphoma (IX): active principles from Juniperus rigida

During the screening of novel chemotherapeutic candidates from plants against adult T-cell leukaemia/lymphoma (ATL), we found that extracts of plants in the Solanaceae, Annonaceae, Apocynaceae, and Rutaceae families showed anti-proliferative activity in the MT-1 and MT-2 cell lines. We have isolated active compounds from these plants in the present research because Cupressaceae plants showed potent anti-proliferative activity in the cell lines. We attempted to isolate the active compounds from the leaves of Juniperus rigida. Using activity-guided fractionation, we isolated 22 compounds, including seven terpenoids, three aromatic compounds, two iridoids, five lignans, and five biflavonoids. The anti-proliferative activities of five diterpenoids were moderate, and those of two biflavonoids were stronger. A lignan (compound 13) showed the strongest activity. These compounds are promising candidates for the treatment of ATL.

Maca (Lepidium meyenii Walp.) inhibits HIV-1 infection through the activity of thiadiazole alkaloids in viral integration

Ethnopharmacology relevanceLepidium meyenii Walp. (maca) has been traditionally used for centuries in the Central Andes region both as food and as medicine. In the last decades, its fertility enhancer properties have gained importance, with the majority of the scientific literature related to this topic. However, other traditional uses are less known as metabolic or infectious diseases. Aim of the studyThe main purpose of this study is to investigate the anti-infectious activity of L. meyenii, specifically in HIV-1 infection. There are previous reports of the transcriptional related activity of L. meyenii extracts in human T lymphocytes via transcription factors as NF-κB. Since T lymphocytes are the main target of HIV-1 infection and NF-κB is strongly involved in HIV-1 transcription, L. meyenii could display antiviral activity. Material and methodsChromatography and spectroscopy techniques were used to isolate and identify the compounds in the active extracts. An antiviral assay system based on recombinant viruses was used to evaluate the anti-HIV activity. Cell toxicity was tested for all the extracts and compounds. Viral entry was studied using VSV-HIV chimera viruses and reverse transcription and viral integration were studied by qPCR of viral DNA in infected cells. Finally, viral transcription was studied in primary lymphocytes transfected with HIV-1 or NF-κB luciferase reporter plasmids. Resultsn-Hexane extracts of purple maca displayed anti-HIV activity in an in vitro assay. A bioassay-guided fractionation led to the identification of three thiadiazole alkaloids with antiviral activity. All the compounds were able to inhibit HIV infection of MT-2 cell lines and primary lymphocytes (PBMCs) with IC50 values in the low micromolar range. The mechanism of action differs between the three compounds: one of them showed activity on viral entry, and all the three compounds inhibited viral integration at low concentrations. Remarkably, none of the compounds inhibited reverse transcription or viral transcription. Conclusionsn-Hexane extracts of the purple ecotype of L. meyenii inhibit HIV-1 infection in vitro and three active thiadiazole alkaloids were isolated acting mainly on viral integration and viral entry.

Daphnane diterpenoid orthoesters with an odd-numbered aliphatic side chain from Daphne pedunculata.

Daphnane diterpenoids were recognized for their extensive range of potent biological activities. In the present study, phytochemical investigation including LC-MS/MS analysis resulted in the identification of five daphnane diterpenoid orthoesters (1-5). Among the five daphnane diterpenoids, two previously unreported compounds, daphnepedunins I and J (2 and 4) were isolated from Daphne pedunculata. The structure of new compounds was elucidated with extensive physicochemical and spectroscopic analyses. Their structure was characterized by the presence of an unusual odd-numbered aliphatic chain connected to an orthoester. The isolated compounds were evaluated for their anti-HIV activity against HIV-1 infection of MT4 cells, and the results indicated that compound 1 showed the most potent anti-HIV activity with an IC50 value of 0.82nM.

Ripasudil as a Potential Therapeutic Agent in Treating Secondary Glaucoma in HTLV-1-Uveitis: An In Vitro Analysis.

Human T-cell leukemia virus type 1 (HTLV-1), a virus that affects 5-10 million people globally, causes several diseases, including adult T-cell leukemia-lymphoma and HTLV-1-associated uveitis (HU). HU is prevalent in Japan and often leads to secondary glaucoma, which is a serious complication. We investigated the efficacy of ripasudil, a Rho-associated coiled coil-forming protein kinase inhibitor, in alleviating changes in human trabecular meshwork cells (hTM cells) infected with HTLV-1. HTLV-1-infected hTM cells were modeled in vitro using MT-2 cells, followed by treatment with varying concentrations of ripasudil. We assessed changes in cell morphology, viability, and inflammatory cytokine levels, as well as NF-κB activation. The results showed that ripasudil treatment changed the cell morphology, reduced the distribution of F-actin and fibronectin, and decreased the levels of certain inflammatory cytokines, such as interleukin (IL)-6, IL-8, and IL-12. However, ripasudil did not significantly affect NF-κB activation or overall cell viability. These findings suggest that ripasudil has the potential to treat secondary glaucoma in patients with HU by modulating cytoskeletal organization and alleviating inflammation in HTLV-1-infected hTM cells. This study lays the foundation for further clinical studies exploring the effectiveness of ripasudil for the treatment of secondary glaucoma associated with HU.

Synthesis, anti-HIV and cytotoxicity evaluation of chiral 2,5-disubstituted 1,3,4-thiadiazole derivatives bearing the sulfonamide scaffold

Abstract In the present study, chiral 2-(4-substiuted phenyl)amino-5-[1-(4-substituted benzenesulphonamido)alkyl]-1,3,4-thiazdiazoles 5a–x were synthesized from enantiopure l-amino acids in a multistep sequence. The starting acids were reacted with arylsulphonyl chlorides to produce N-arylsulfonyl amino acids 1a–h, followed by esterification to obtain the corresponding esters 2a–h. Treatment of esters with hydrazine hydrate afforded the corresponding hydrazides 3a–h. The coupling of hydrazides with aryl isothiocyanates followed by cyclization gave the target thiadiazoles 5a–x in good yields. The new synthesized compounds were assayed against HIV-1 and HIV-2 in MT-4 cells using MTT assay. Compounds 5s, 5v and 5w showed IC50 values of &gt; 1.58, &gt;1.98 and &gt; 2.04 μm with SI &gt; 1, respectively, indicating that these compounds were cytotoxic at concentrations values of 1.58, 1.98 and 2.04 μm, respectively.

Purification Method of Extracellular Vesicles Derived from Human T-Cell Leukemia Virus Type 1-Infected Cells without Virions.

To mediate intercellular communication, cells produce extracellular vesicles (EVs). These EVs transport many biomolecules such as proteins, nucleic acids, and lipids between cells and regulate pathophysiological actions in the recipient cell. However, EVs and virus particles produced from virus-infected cells are of similar size and specific gravity; therefore, the separation and purification of these two particles is often controversial. When analyzing the physiological functions of EVs from virus-infected cells, the presence or absence of virus particle contamination must always be verified. The human T-cell leukemia virus type 1 (HTLV-1)-infected cell line, MT-2, produces EVs and virus particles. Here, we validated a method for purifying EVs from MT-2 cell culture supernatants while avoiding HTLV-1 viral particle contamination. EV fractions were collected using a combination of immunoprecipitation with Tim-4, which binds to phosphatidylserine, and polymer precipitation. The HTLV-1 viral envelope protein, gp46, was not detected in the EV fraction. Proteomic analysis revealed that EV-constituted proteins were predominant in this EV fraction. Furthermore, the EVs were found to contain the HTLV-1 viral genome. The proposed method can purify EVs while avoiding virus particle contamination and is expected to contribute to future research on EVs derived from HTLV-1-infected cells.

Characterization of the MT-2 Treg-like cell line in the presence and absence of forkhead box P3 (FOXP3).

CD4+ forkhead box P3 (FOXP3)+ regulatory T cells (Tregs) are essential in maintaining immune tolerance and suppressing excessive immune responses. Tregs also contribute to tissue repair processes distinct from their roles in immune suppression. For these reasons, Tregs are candidates for targeted therapies for inflammatory and autoimmune diseases, and in diseases where tissue damage occurs. MT-2 cells, an immortalized Treg-like cell line, offer a model to study Treg biology and their therapeutic potential. In the present study, we use clustered regularly interspaced palindromic repeats (CRISPR)-mediated knockdown of FOXP3 in MT-2 cells to understand the transcriptional and functional changes that occur when FOXP3 is lost and to compare MT-2 cells with primary human Tregs. We demonstrate that loss of FOXP3 affects the transcriptome of MT-2 cells and that FOXP3's potential downstream targets include a wide range of transcripts that participate in the cell cycle, promote growth and contribute to inflammatory processes, but do not wholly simulate previously reported human primary Treg transcriptional changes in the absence of FOXP3. We also demonstrate that FOXP3 regulates cell cycling and proliferation, expression of molecules crucial to Treg function and MT-2 cell-suppressive activities. Thus, MT-2 cells offer opportunities to address regulatory T-cell functions in vitro.

Umbelliprenin improved anti-proliferative effects of ionizing radiation on adult T-cell leukemia/lymphoma cells via interaction with CDK6; an in vitro and in silico study.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive malignancy with poor survival rates. The efficacy of radiotherapy in ATL needs enhancement with radiosensitizing agents. This study investigated whether umbelliprenin (UMB) could improve the therapeutic effects of ionizing radiation (IR) in ATL cells. UMB, a naturally occurring prenylated coumarin, exhibits anticancer properties and has shown synergistic effects when combined with chemotherapeutic drugs. Despite this promising profile, there is a notable lack of research on its potential combinatorial effects with IR, particularly for ATL treatment. UMB was extracted fromFerula persicausing thin layer chromatography. MT-2 cells were treated with UMB alone and in combination with various doses of IR, and cell proliferation was assessed via alamarBlue assay. Flow cytometry with annexin V and PI staining was conducted, and candidate gene expression was analyzed by qPCR.In silicoanalysis involved identifying pathogenic targets of ATL, constructing protein-protein interaction(PPI) networks, and evaluating CDK6 expression in MT-2 cells. Molecular docking was used to determine the interaction between UMB and CDK6. The alamarBlue assay and flow cytometry showed that pretreating ATL cells with UMB significantly (p< .0001) enhanced anti-proliferative effects of IR. The combination index indicated a synergistic effect between UMB and IR. qPCR revealed significant (p< .0001) downregulation ofCD44, CDK6, c-MYC, andcFLIPL, and overexpression ofcFLIPS. Computational analysis identified CDK6 as a hub gene in the PPI network, and CDK6 overexpression was confirmed in MT-2 cells. Molecular docking revealed a favorable binding interaction between UMB and the ATP-binding site of CDK6, with a JAMDA score of-2.131, surpassing the control selonsertib. The current study provides evidence that UMB enhances the anti-proliferative effects of IR on ATL cells, and highlights the significance of targeting CDK6 in combinatorial approaches.

New azaaurone derivatives as potential multitarget agents in HIV-TB coinfection.

Tuberculosis (TB) disease, caused by Mycobacterium tuberculosis (Mtb) is the leading cause of death among people with human immunodeficiency virus (HIV) infection. No dual-target drug is currently being used to simultaneously treat both infections. This work aimed to obtain new multitarget HIV-TB agents, with the goal of optimizing treatments and preventing this coinfection. These compounds incorporate the structural features of azaaurones as anti-Mtb and zidovudine (AZT) as the antiretroviral moiety. The azaaurone scaffold displayed submicromolar activities against Mtb, and AZT is a potent antiretroviral drug. Six derivatives were synthetically generated, and five were evaluated against both infective agents. Evaluations of anti-HIV activity were carried out in HIV-1-infected MT-4 cells and on endogenous HIV-1 reverse transcriptase (RT) activity. The H37Rv strain was used for anti-Mtb assessments. Most compounds displayed potent antitubercular and moderate anti-HIV activity. (E)-12 exhibited a promising multitarget profile with an MIC90 of 2.82 µM and an IC50 of 1.98 µM in HIV-1-infected T lymphocyte cells, with an 84% inhibition of RT activity. Therefore, (E)-12 could be the first promising compound from a family of multitarget agents used to treat HIV-TB coinfection. In addition, the compound could offer a prototype for the development of new strategies in scientific research to treat this global health issue.

Non-canonical NFKB signaling endows suppressive function through FOXP3-dependent regulatory T cell program

Regulatory T cells (Tregs) play a central role in modulating adaptive immune responses in humans and mice. The precise biological role of non-canonical nuclear factor ‘κ-light-chain-enhancer’ of activated B cells (NFKB) signaling in human Tregs has yet to be fully elucidated. To gain insight into this process, a Treg-like cell line (MT-2) was genetically modified using CRISPR/Cas9. Interestingly, NFKB2 knockout MT-2 cells exhibited downregulation of FOXP3, while NFKB1 knockout did not. Additionally, mRNA expression of FOXP3-dependent molecules was significantly reduced in NFKB2 knockout MT-2 cells. To better understand the functional role of the NFKB signaling, the NFKB1/NFKB2 loci of human primary Tregs were genetically edited using CRISPR/Cas9. Similar to MT-2 cells, NFKB2 knockout human Tregs displayed significantly reduced FOXP3 expression. Furthermore, NFKB2 knockout human Tregs showed downregulation of FOXP3-dependent molecules and a diminished suppressive function compared to wild-type and NFKB1 knockout Tregs. These findings indicate that non-canonical NFKB signaling maintains a Treg-like phenotype and suppressive function in human Tregs through the FOXP3-dependent regulatory T cell program.

The master antioxidant defense is activated during EBV latent infection.

To our knowledge, this is the first report delineating the activation of the master antioxidant defense during EBV latency. We show that EBV-triggered reactive oxygen species production activates the Keap1-NRF2 pathway in EBV-transformed cells, and LMP1 plays a major role in this event, and the stress-related kinase TBK1 is required for NRF2 activation. Moreover, we show that the Keap1-NRF2 pathway is important for cell proliferation and EBV latency maintenance. Our findings disclose how EBV controls the balance between oxidative stress and antioxidant defense, which greatly improve our understanding of EBV latency and pathogenesis and may be leveraged to opportunities toward the improvement of therapeutic outcomes in EBV-associated diseases.

Characterization of acute and subacute immune response to boiling histotripsy ablation of pancreatic adenocarcinoma

Boiling histotripsy (BH) is a cavitation-based pulsed focused ultrasound method of mechanical tissue disintegration. When applied to tumor ablation, BH was shown in a number of preclinical studies to stimulate antitumor immune responses, with the extent and dynamics depending on the tumor microenvironment. In this work, we assessed the response of pancreatic ductal adenocarcinoma (PDAC)—an immunologically “cold” tumor—to BH ablation. C57BL/6J mice (n = 6 per group) were bilaterally subcutaneously grafted with KPC-derived mT4 cell line in the hind limbs. When one of the two tumors reached 8 mm, 80% of its volume was ablated with BH (1.5 MHz, 3 ms pulses, 1% duty cycle, 450 W power, 15 pulses/point). The tumors, inguinal lymph nodes and spleens were harvested at 1-, 3-, and 6-day time points and processed for immune phenotyping through flow cytometry, histology, and immunohistochemistry. At earlier time points, the response within the tumor was dominated by neutrophils, and by day 6—by inflammatory monocytes both in treated and contralateral sides versus sham. Transient increases in B cells, neutrophils, NK, NKT cells, and monocytes were observed in the ipsilateral lymph nodes and in spleens on day 3, and mostly subsided by day 6. These data will inform further studies in optimization of combination therapies for PDAC. [Work supported by Focused Ultrasound Foundation.]

Higher Infectivity of the Human Immunodeficiency Virus in Sensitive Cells with a Modification of the CCR5 Gene.

As a natural mutation of the human ccr5 gene has been shown to confer resistance to human immunodeficiency virus type 1 (HIV-1) infection, a new avenue has opened in the development of alternative treatment approaches through genome editing. One of the two chemokine co-receptors of the plasma membrane is utilized by HIV-1 to infect CD4+ cells. HIV-1 strains that utilize CCR5 circulate in early infection, and strains that utilize CXCR4 circulate at advanced stages. A complex relationship may exist in the expression regulation of the receptors and may affect virus replication in cells that normally do not express CCR5 on the membrane, such as the MT-4 cell line. MT-4 cells were used to study the effect of ccr5 modification HIV-1 replication in vitro. Genetic modification of ccr5 in MT-4 cells was shown to increase the activities of HIV-1 strains, especially in homozygote. The results indicate that genome editing should be performed with caution in human cells and that the issue needs comprehensive investigation.

Ethyl Gallate: Promising Cytoprotective against HIV-1-Induced Cytopathy and Antiretroviral-Induced Cytotoxicity.

HIV-1 infection in cell culture is typically characterized by certain cytopathic effects such as vacuolization of cells and development of syncytia, which further lead to cell death. In addition, the majority of drugs during HIV treatment exhibit serious adverse effects in patients, apart from their beneficial role. During the screening of cytoprotective agents to protect the cells from HIV-1-associated cell death and also drug-associated toxicity, antioxidants from a natural source are assumed to be a choice. A well-known antioxidant, ethyl gallate (EG), was selected for cytoprotection studies which have already been proven as an anti-HIV agent. The main objective of the study was to explore the cytoprotective potential of EG against HIV-1-induced cytopathic effect and antiretroviral drug toxicity. DPPH free radical scavenging assay was performed with EG to find the effective concentration for antioxidant activity. HIV-1infection-associated cytopathic effects and further rescue by EG were studied in MT-2 lymphocytes by the microscopic method and XTT cytopathic assays. The cellular toxicity of different antiretroviral drugs in different cell lines and the consequent cytoprotective effectiveness of EG were investigated using an MTT cell viability assay. Like ascorbic acid, EG exhibited promising antioxidant activity. HIV-1 infection of MT2 cells induces cell death often referred to as the cytopathic effect. In addition, the usage of antiretroviral drugs also causes severe adverse effects like cytotoxicity. In this context, EG was tested for its cytoprotective properties against HIV-1-induced cytopathic effect and drug-mediated cellular toxicity. EG reclaimed back the MT2 cells from HIV-1-induced cell death. Antiretroviral drugs, such as ritonavir, efavirinz, AZT, and nevirapine, were tested for their toxicity and induced more cell death at higher concentrations in different tissue models such as the liver (THLE-3), lung (AEpiCM), colorectal (HT-29), and brain (U87 MG). Pretreated cells with EG were rescued from the toxic doses of ART. EG was found to be exhibited cytoprotection not only from HIV-1-linked cell death but also from the chemotoxicity of antiretroviral drugs. Evidently, EG could be a cytoprotective supplement in the management of AIDS along with its enormous antioxidant benefits.

The unique activity of saponin: Induction of cytotoxicity in HTLV-1 infected cells

Infection with the retrovirus human T-cell leukemia virus type 1 (HTLV-1) sometimes causes diseases that are difficult to cure. To find anti-HTLV-1 natural compounds, we opted to screen using the HTLV-1-infected T-cell line, MT-2. Based on our results, an extract of the pulp/seeds of Akebia quinata Decaisne fruit killed MT-2 cells but did not affect the Jurkat cell line that was not infected with virus. To determine the active ingredients, seven saponins with one-six sugar moieties were isolated from A. quinata seeds, and their activities against the two cell lines were examined. Both cell lines were killed in a similar manner by Akebia saponins A and B. Further, Akebia saponins D, E, PK and G did not exhibit cytotoxicity. Akebia saponin C had a similar activity to the extract found in the screening. This compound was found to enhance Gag aggregation, induce the abnormal cleavage of Gag, suppress virion release, and preferentially kill HTLV-1 infected cells; however, their relationship remains elusive. Our findings may lead to the development of new therapies for infectious diseases based on the removal of whole-virus-infected cells.