Bergenin potentiates BCG efficacy by enriching mycobacteria-specific adaptive memory responses via the Akt-Foxo-Stat4 axis.

The extensive inability of the BCG vaccine to produce long-term immune protection has not only accelerated the disease burden but also progressed towards the onset of drug resistance. In our previous study, we have reported the promising effects of Bergenin (Berg) in imparting significant protection as an adjunct immunomodulator against tuberculosis (TB). In congruence with our investigations, we delineated the impact of Berg on T cells, wherein it enhanced adaptive memory responses by modulating key transcription factors, STAT4 and Akt. We translated this finding into the vaccine model of TB and observed a notable reduction in the burden of Mycobacterium tuberculosis (M.tb) in BCG-Berg co-immunized mice as compared to BCG vaccination. Moreover, Berg, along with BCG, also aided in a heightened proinflammatory response milieu that corroborates the host protective immune response against TB. Furthermore, this response aligns with the escalated central and resident memory responses by modulating the Akt-Foxo-Stat4 axis, which plays a crucial role in enhancing the vaccine efficacy of BCG. These findings showcase the utilization of immunomodulator Berg as an immunoprophylactic agent to upgrade immunological memory, making it a more effective defender against TB.

Unravelling the potential of Triflusal as an anti-TB repurposed drug by targeting replication protein DciA.

The increasing prevalence of drug-resistant Tuberculosis (TB) is imposing extreme difficulties in controlling the TB infection rate globally, making treatment critically challenging. To combat the prevailing situation, it is crucial to explore new anti-TB drugs with a novel mechanism of action and high efficacy. The Mycobacterium tuberculosis (M.tb)DciA is an essential protein involved in bacterial replication and regulates its growth. DciA interacts with DNA and provides critical help in binding other replication machinery proteins to the DNA. Moreover, the lack of any structural homology of M.tb DciA with human proteins makes it an appropriate target for drug development. In this study, FDA-approved drugs were virtually screened against M.tb DciA to identify potential inhibitors. Four drugs namely Lanreotide, Risedronate, Triflusal, and Zoledronic acid showed higher molecular docking scores. Further, molecular dynamics simulations analysis of DciA-drugs complexes reported stable interaction, more compactness, and reduced atomic motion. The anti-TB activity of drugs was further evaluated under in vitro and ex vivo conditions where Triflusal was observed to have the best possible activity with the MIC of 25 µg/ml. Our findings present novel DciA inhibitors and anti-TB activity of Triflusal. Further investigations on the use of Triflusal may lead to the discovery of a new anti-TB drug.

Atosiban and Rutin exhibit anti-mycobacterial activity - An integrated computational and biophysical insight toward drug repurposing strategy against Mycobacterium tuberculosis targeting its essential enzyme HemD.

With the advancements of high throughput computational screening procedures, drug repurposing became the privileged framework for drug discovery. The structure-based drug discovery is the widely used method of drug repurposing, consisting of computational screening of compounds and testing them in-vitro. This current method of repurposing leaves room for mechanistic insights into how these screened hits interact with and influence their targets. We addressed this gap in the current study by integrating highly sensitive biophysical methods into existing computational repurposing methods. We also corroborated our computational and biophysical findings on H37Rv for the anti-mycobacterial action of selected drugs in-vitro and ex-vivo conditions. Atosiban and Rutin were screened as highly interacting hits against HemD through multi-stage docking and were cross-validated in biophysical studies. The affinity of these drugs (K ~ 106 M-1) was quantified using fluorescence quenching studies. Differential Scanning Fluorimetry (DSF) and urea-based chemical denaturation studies revealed a destabilizing effect of these drugs on target which was further validated using MD simulations. Conformational rearrangements of secondary structures were established using CD spectra and intrinsic fluorescence. Furthermore, Atosiban and Rutin inhibited M.tb growth in-vitro and ex-vivo while remaining non-toxic to mice peritoneal macrophages.

Adjunct therapy with all-trans-retinoic acid improves therapeutic efficacy through immunomodulation while treating tuberculosis with antibiotics in a murine model.

Tuberculosis (TB) is the second leading infectious killer after COVID-19. Standard anti-tubercular drugs exhibit various limitations like toxicity, lengthy, and unresponsive to dormant and drug resistant organisms. Here, we report that all-trans-retinoic acid (ATRA) improves M.tb clearance in mice while treating with anti-tubercular drug isoniazid (INH). Interestingly, ATRA promoted activities of lysosomes, mitochondria, and production of various inflammatory mediators in macrophages. Furthermore, ATRA upregulated the expression of genes of lipid metabolic pathways in macrophages. Along this line, we registered that ATRA activated MEK/ERK pathway in macrophages in-vitro and MEK/ERK and p38 MAPK pathways in the mice. Finally, ATRA induced both Th1 and Th17 responses in lungs and spleens of M.tb-infected mice. Taken together, these data indicated that ATRA provides beneficial adjunct therapeutic value by modulating MEK/ERK and p38 MAPK pathways and thus warrants further testing for human use.

Cotreatment With Clofazimine and Rapamycin Eliminates Drug-Resistant Tuberculosis by Inducing Polyfunctional Central Memory T-Cell Responses.

Mycobacterium tuberculosis, the causative agent of tuberculosis, is acquiring drug resistance at a faster rate than the discovery of new antibiotics. Therefore, alternate therapies that can limit the drug resistance and disease recurrence are urgently needed. Emerging evidence indicates that combined treatment with antibiotics and an immunomodulator provides superior treatment efficacy. Clofazimine (CFZ) enhances the generation of T central memory (TCM) cells by blocking the Kv1.3+ potassium channels. Rapamycin (RAPA) facilitates M. tuberculosis clearance by inducing autophagy. In this study, we observed that cotreatment with CFZ and RAPA potently eliminates both multiple and extensively drug-resistant (MDR and XDR) clinical isolates of M. tuberculosis in a mouse model by inducing robust T-cell memory and polyfunctional TCM responses. Furthermore, cotreatment reduces the expression of latency-associated genes of M. tuberculosis in human macrophages. Therefore, CFZ and RAPA cotherapy holds promise for treating patients infected with MDR and XDR strains of M. tuberculosis.

Biapenem, a Carbapenem Antibiotic, Elicits Mycobacteria Specific Immune Responses and Reduces the Recurrence of Tuberculosis.

Tuberculosis (TB) still tops the list of global health burdens even after COVID-19. However, it will sooner transcend the current pandemic due to the prevailing risk of reactivation of latent TB in immunocompromised individuals. The indiscriminate misuse and overuse of antibiotics have resulted in the emergence of deadly drug-resistant variants of Mycobacterium tuberculosis (M.tb). This study aims to characterize the functionality of the carbapenem antibiotic-Biapenem (BPM) in generating long-lasting immunity against TB. BPM treatment significantly boosted the activation status of the innate immune arm-macrophages by augmenting p38 signaling. Macrophages further primed and activated the adaptive immune cells CD4+ and CD8+ T-cells in the lung and spleen of the infected mice model. Furthermore, BPM treatment significantly amplified the polarization of T lymphocytes toward inflammatory subsets, such as Th1 and Th17. The treatment also helped generate a long-lived central memory T-cell subset. The generation of central memory T lymphocyte subset upon BPM treatment in the murine model led to a significant curtailing in the recurrence of TB due to reactivation and reinfection. These results suggest the potentiality of BPM as a potent adjunct immunomodulator to improve host defense against M.tb by enriching long-term protective memory cells. IMPORTANCE Tuberculosis (TB) caused by Mycobacterium tuberculosis (M.tb) tops the list of infectious killers around the globe. The emergence of drug-resistant variants of M.tb has been a major hindrance toward realizing the "END TB" goal. Drug resistance has amplified the global burden toward the quest for novel drug molecules targeting M.tb. Host-directed therapy (HDT) offers a lucrative alternative to tackle emerging drug resistance and disease relapse by strengthening the host's immunity. Through our present study, we have tried to characterize the functionality of the carbapenem antibiotic-Biapenem (BPM). BPM treatment significantly augmented long-lasting immunity against TB by boosting the innate and adaptive immune arms. The generation of long-lived central memory T lymphocyte subset significantly improved the disease outcome and provided sterilizing immunity in the murine model of TB. The present investigation's encouraging results have helped us depict BPM as a potent adjunct immunomodulator for treating TB.

Revisiting the role of mesenchymal stem cells in tuberculosis and other infectious diseases.

Mesenchymal stem cells (MSCs) play diverse roles ranging from regeneration and wound healing to immune signaling. Recent investigations have indicated the crucial role of these multipotent stem cells in regulating various aspects of the immune system. MSCs express unique signaling molecules and secrete various soluble factors that play critical roles in modulating and shaping immune responses, and in some other cases, MSCs can also exert direct antimicrobial effects, thereby helping with the eradication of invading organisms. Recently, it has been demonstrated that MSCs are recruited at the periphery of the granuloma containing Mycobacterium tuberculosis and exert "Janus"-like functions by harboring pathogens and mediating host protective immune responses. This leads to the establishment of a dynamic balance between the host and the pathogen. MSCs function through various immunomodulatory factors such as nitric oxide (NO), IDO, and immunosuppressive cytokines. Recently, our group has shown that M.tb uses MSCs as a niche to evade host protective immune surveillance mechanisms and establish dormancy. MSCs also express a large number of ABC efflux pumps; therefore, dormant M.tb residing in MSCs are exposed to a suboptimal dose of drugs. Therefore, it is highly likely that drug resistance is coupled with dormancy and originates within MSCs. In this review, we discussed various immunomodulatory properties of MSCs, their interactions with important immune cells, and soluble factors. We also discussed the possible roles of MSCs in the outcome of multiple infections and in shaping the immune system, which may provide insight into therapeutic approaches using these cells in different infection models.

SIRT2 inhibition by AGK2 enhances mycobacteria-specific stem cell memory responses by modulating beta-catenin and glycolysis.

Bacille Calmette-Guerin (BCG) generates limited long-lasting adaptive memory responses leading to short-lived protection against adult pulmonary tuberculosis (TB). Here, we show that host sirtuin 2 (SIRT2) inhibition by AGK2 significantly enhances the BCG vaccine efficacy during primary infection and TB recurrence through enhanced stem cell memory (TSCM) responses. SIRT2 inhibition modulated the proteome landscape of CD4+ T cells affecting pathways involved in cellular metabolism and T-cell differentiation. Precisely, AGK2 treatment enriched the IFNγ-producing TSCM cells by activating ß-catenin and glycolysis. Furthermore, SIRT2 specifically targeted histone H3 and NF-κB p65 to induce proinflammatory responses. Finally, inhibition of the Wnt/ß-catenin pathway abolished the protective effects of AGK2 treatment during BCG vaccination. Taken together, this study provides a direct link between BCG vaccination, epigenetics, and memory immune responses. We identify SIRT2 as a key regulator of memory T cells during BCG vaccination and project SIRT2 inhibitors as potential immunoprophylaxis against TB.

Combating the challenges of COVID-19 pandemic: Insights into molecular mechanisms, immune responses and therapeutics against SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes lethal coronavirus disease (COVID-19). SARS-CoV-2 has been the chief source of threat to public health and safety from 2019 to the present. SARS-CoV-2 caused a sudden and significant rise in hospitalization due to respiratory issues and pneumonia. We are consistently uncovering new information about SARS-CoV-2, and yet so much is to explore to implement efficient interventions to combat the emergent variants and spread of the ongoing pandemic. Information regarding the existing COVID-19 pandemic is streamlining continuously. However, clinical symptoms of SARS-CoV-2 infections spanning from asymptomatic infection to severe death-instigating disease remain consistent with preliminary reports. In this review, we have briefly introduced highlights of the COVID-19 pandemic and features of SARS-CoV-2. We have focused on current knowledge of innate and adaptive immune responses during SARS-CoV-2 infections and persisting clinical features of recovered patients. Furthermore, we have discussed how these immune responses are not tightly regulated and imbalance can direct the latter phases of COVID-19, long-COVID symptoms, and cause detrimental immunopathogenesis. COVID-19 vaccines are also discussed in detail to describe the efforts going around the world to control and prevent the infection. Overall, we have summarized the current knowledge on the immunology of SARS-CoV-2 infection and the utilization of that knowledge in the development of a suitable COVID-19 therapeutics and vaccines.

Berberine governs NOTCH3/AKT signaling to enrich lung-resident memory T cells during tuberculosis.

Stimulation of naïve T cells during primary infection or vaccination drives the differentiation and expansion of effector and memory T cells that mediate immediate and long-term protection. Despite self-reliant rescue from infection, BCG vaccination, and treatment, long-term memory is rarely established against Mycobacterium tuberculosis (M.tb) resulting in recurrent tuberculosis (TB). Here, we show that berberine (BBR) enhances innate defense mechanisms against M.tb and stimulates the differentiation of Th1/Th17 specific effector memory (TEM), central memory (TCM), and tissue-resident memory (TRM) responses leading to enhanced host protection against drug-sensitive and drug-resistant TB. Through whole proteome analysis of human PBMCs derived from PPD+ healthy individuals, we identify BBR modulated NOTCH3/PTEN/AKT/FOXO1 pathway as the central mechanism of elevated TEM and TRM responses in the human CD4+ T cells. Moreover, BBR-induced glycolysis resulted in enhanced effector functions leading to superior Th1/Th17 responses in human and murine T cells. This regulation of T cell memory by BBR remarkably enhanced the BCG-induced anti-tubercular immunity and lowered the rate of TB recurrence due to relapse and re-infection. These results thus suggest tuning immunological memory as a feasible approach to augment host resistance against TB and unveil BBR as a potential adjunct immunotherapeutic and immunoprophylactic against TB.

Withaferin A Protects against Primary and Recurrent Tuberculosis by Modulating Mycobacterium-Specific Host Immune Responses.

The fate of Mycobacterium tuberculosis infection is governed by immune signaling pathways that can either eliminate the pathogen or result in tuberculosis (TB). Anti-TB therapy (ATT) is extensive and is efficacious only against active, drug-sensitive strains of M. tuberculosis. Due to severe side effects, ATT often causes impairment of host immunity, making it imperative to use novel immunotherapeutics for better clinical outcomes. In this study, we have explored the immunomodulatory potential of withaferin A (WA) as an immunotherapeutic against TB. Here, we demonstrate that WA can constrain intracellular drug-sensitive and -resistant strains of M. tuberculosis by augmenting host immune responses. We also established the potential of WA treatment in conjunction with isoniazid. We show that WA directs the host macrophages toward defensive M1 polarization and enhances TH1 and TH17 immune responses against M. tuberculosis infection. The reduced bacterial burden upon T cell adoptive transfer further corroborated the augmented T cell responses. Interestingly, WA stimulated the generation of T cell memory populations by instigating STAT signaling, thereby reducing the rate of TB recurrence due to reactivation and reinfection. We substantiate the prospects of WA as a potent adjunct immunomodulator that enriches protective memory cells by prompting STAT signaling and improves host defense against M. tuberculosis. IMPORTANCE Despite being extensive, conventional antituberculosis therapy (ATT) is barely proficient in providing sterile immunity to tuberculosis (TB). Failure to constrain the escalating global TB burden due to the emergence of drug-resistant bacterial strains and immune dampening effects of ATT necessitates adjunct immunotherapeutics for better clinical outcomes. We evaluated the prospects of withaferin A (WA), an active constituent of Withania somnifera, as an adjunct immunomodulator against diverse M. tuberculosis strains. WA efficiently restricts the progression of TB by stimulating antimycobacterial host responses, protective immune signaling, and activation of diverse immune cell populations. Protective effects of WA can be attributed to the enrichment of memory T cells by induction of STAT signaling, thereby enhancing resistance to reinfections and reactivation of disease. We ascertained the immunotherapeutic potential of WA in boosting host immune responses against M. tuberculosis.

The 1, 2-ethylenediamine SQ109 protects against tuberculosis by promoting M1 macrophage polarization through the p38 MAPK pathway.

Directly Observed Treatment Short-course (DOTs), is an effective and widely recommended treatment for tuberculosis (TB). The antibiotics used in DOTs, are immunotoxic and impair effector T cells, increasing the risk of re-infections and reactivation. Multiple reports suggest that addition of immune-modulators along with antibiotics improves the effectiveness of TB treatment. Therefore, drugs with both antimicrobial and immunomodulatory properties are desirable. N1-(Adamantan-2-yl)-N2-[(2E)-3,7-dimethylocta-2,6-dien-1-yl]ethane-1,2-diamine (SQ109) is an asymmetric diamine derivative of adamantane, that targets Mycobacterial membrane protein Large 3 (MmpL3). SQ109 dissipates the transmembrane electrochemical proton-gradient necessary for cell-wall biosynthesis and bacterial activity. Here, we examined the effects of SQ109 on host-immune responses using a murine TB model. Our results suggest the pro-inflammatory nature of SQ109, which instigates M1-macrophage polarization and induces protective pro-inflammatory cytokines through the p38-MAPK pathway. SQ109 also promotes Th1 and Th17-immune responses that inhibit the bacillary burden in a murine model of TB. These findings put forth SQ109 as a potential-adjunct to TB antibiotic therapy.

Epigenetic code during mycobacterial infections: therapeutic implications for tuberculosis.

Epigenetics involves changing the gene function without any change in the sequence of the genes. In the case of tuberculosis (TB) infections, the bacilli, Mycobacterium tuberculosis (M.tb), uses epigenetics as a tool to protect itself from the host immune system. TB is a deadly disease-causing maximum death per year due to a single infectious agent. In the case of TB, there is an urgent need for novel host-directed therapies which can effectively target the survival and long-term persistence of the bacteria without developing drug resistance in the bacterial strains while also reducing the duration and toxicity associated with the mainstream anti-TB drugs. Recent studies have suggested that TB infection has a significant effect on the host epigenome thereby manipulating the host immune response in the favor of the pathogen. M.tb alters the activation status of key genes involved in the immune response against TB to promote its survival and subvert the antibacterial strategies of the host. These changes are reversible and can be exploited to design very efficient host-directed therapies to fight against TB. This review has been written with the purpose of discussing the role of epigenetic changes in TB pathogenesis and the therapeutic approaches involving epigenetics, which can be utilized for targeting the pathogen.

Biochemical characterization of Plasmodium falciparum parasite specific helicase 1 (PfPSH1).

Malaria, a disease caused by infection with parasites of the genus Plasmodium, causes millions of deaths worldwide annually. Of the five Plasmodium species that can infect humans, Plasmodium falciparum causes the most serious parasitic infection. The emergence of drug resistance and the ineffectiveness of old therapeutic regimes against malaria mean there is an urgent need to better understand the basic biology of the malaria parasite. Previously, we have reported the presence of parasite-specific helicases identified through genome-wide analysis of the P. falciparum (3D7) strain. Helicases are involved in various biological pathways in addition to nucleic acid metabolism, making them an important target of study. Here, we report the detailed biochemical characterization of P. falciparum parasite-specific helicase 1 (PfPSH1) and the effect of phosphorylation on its biochemical activities. The C-terminal of PfPSH1 (PfPSH1C) containing all conserved domains was used for biochemical characterization. PfPSH1C exhibits DNA- or ribonucleic acid (RNA)-stimulated ATPase activity, and it can unwind DNA and RNA duplex substrates. It shows bipolar directionality because it can translocate in both (3'-5' and 5'-3') directions. PfPSH1 is mainly localized to the cytoplasm during early stages (including ring and trophozoite stages of intraerythrocytic development), but at late stages, it is partially located in the cytoplasm. The biochemical activities of PfPSH1 are upregulated after phosphorylation with PKC. The detailed biochemical characterization of PfPSH1 will help us understand its functional role in the parasite and pave the way for future studies.

Predictors of Metabolic Syndrome among Polycystic Ovary Syndrome Sisters.

AIMS: Metabolic syndrome among PCOS sisters may vary depending on the phenotype. The aim of the present study was to analyze the prevalence of metabolic syndrome among different phenotypes of PCOS sisters. DESIGN: Case control study. MATERIALS AND METHODS: Two hundred sisters of PCOS patients and 99 age matched healthy controls underwent history, clinical examination, biochemical parameters for metabolic syndrome and hormonal assessment. RESULTS: Of 200 sisters, 85 were unaffected (UA group), 21 sisters had hyperandrogenemia (HA group), and 94 sisters had irregular periods or hyperandrogenemia. We observed that the frequency of metabolic syndrome among PCOS sisters was comparable to age and weight matched controls (30% vs 27%). The prevalence of metabolic syndrome was higher in HA and AFFECTED sisters (around 30% in both) compared to UA sisters (20%). The presence of metabolic syndrome was significantly associated with age, BMI, HOMA-IR and free testosterone. After correction for age and BMI, metabolic syndrome was significantly associated with HOMA-IR (P - 0.05) and free testosterone (P - 0.03). CONCLUSION: Based on above findings, we conclude that affected sisters and those with higher age, BMI and hyperandrogenemia have a high risk of metabolic syndrome compared to unaffected sisters.

Menstrual Cycle Abnormalities in Patients with Prolactinoma and Drug-induced Hyperprolactinemia.

BACKGROUND AND OBJECTIVE: Hyperprolactinemia affects the reproductive endocrine axis; however, the degree of dysfunction may vary depending on etiology. The aim of the present study was to analyze menstrual cyclicity in patients with prolactinoma and drug-induced hyperprolactinemia (DIH). METHODOLOGY: Patients with prolactinoma and DIH were retrospectively analyzed for menstrual cyclicity at presentation and response to therapy. RESULTS: Of 128 females with hyperprolactinemia, 58 had prolactinoma (41 microadenoma and 17 macroadenoma) and 39 had DIH. Patients with prolactinoma had higher prolactin levels and increased frequency of oligomenorrhea (77.5% vs. 46%) as compared to DIH. Patients with macroprolactinoma had more severe menstrual disturbances compared to microprolactinoma. A higher percentage of patients with microprolactinoma and DIH achieved regular menstrual cycles compared to macroprolactinoma postcabergoline treatment (85% and 90% vs. 65%). There was no correlation between time to regularization of menstrual cycles with age, menstrual cycle length, duration of menstrual irregularity, or initial prolactin level in patients with prolactinoma. Linear regression analysis showed a significant association between time to regularization of menstrual cycles with time to normalization of prolactin levels (P = 0.001). CONCLUSION: There is a prompt restoration of menstrual cycles in patients with microprolactinoma and DIH. Patients with macroprolactinoma have more severe menstrual disturbances and lesser frequency of cycle restoration postcabergoline treatment compared to microprolactinoma and DIH.

Menstrual cyclicity post OC withdrawal in PCOS: Use of non-hormonal options.

There is no data on menstrual cyclicity post oral contraceptive (OC) withdrawal with nonhormonal options in PCOS patients. OC could affect obesity, insulin and gonadotropins factors integral to pathogenesis of PCOS, thereby adversely affecting the HPG axis. Menstrual cycles of PCOS patients were retrospectively studied post OCP. Patients developing regular versus irregular cycles post OC were compared. Forty-eight PCOS patients were followed for an average of 1.9 years post OC. Thirty-six (75%) achieved regular cycles over a period of one year with other nonhormonal options like spironolactone and metformin. Seven patients required no treatment. Patients who continued to have irregular cycles had a longer pre OC cycle length (p < 0.01) and a greater duration of menstrual irregularity (p < 0.02), though age, BMI and hormones were similar in the two groups. In conclusion, spironolactone and metformin are effective nonhormonal options for regular periods post OC. Around 15% PCOS may not require any treatment post OC.

Polycystic ovarian syndrome in patients with lipodystrophy: Report of 2 cases with review of literature.

Lipodystrophy is a clinical disorder characterized by maldistribution of body fat. Hyperinsulinemia, insulin resistance, and abnormalities of glucose homeostasis are commonly described among these patients. Hyperinsulinemia is also involved in the pathogenesis of polycystic ovarian syndrome, a condition, described rarely in patients with lipodystrophy. Here, we describe 2 females of partial lipodystrophy who presented with features of polycystic ovarian disease. Both had severe hyperinsulinemia and irregular periods, one had hyperandrogenism and hirsuitism while the other was non-hirsuite.