Glutathione in HIV-Associated Neurocognitive Disorders.

A large portion of patients with Human Immunodeficiency Virus (HIV) have neurologic sequelae. Those with better-controlled HIV via antiretroviral therapies generally have less severe neurologic symptoms. However, for many patients, antiretrovirals do not adequately resolve symptoms. Since much of the pathogenesis of HIV/AIDS (Autoimmune Deficiency Syndrome) involves oxidative stress either directly, through viral interaction, or indirectly, through inflammatory mechanisms, we have reviewed relevant trials of glutathione supplementation in each of the HIV-associated neurocognitive diseases and have found disease-specific results. For diseases for which trials have not been completed, predicted responses to glutathione supplementation are made based on relevant mechanisms seen in the literature. It is not sufficient to conclude that all HIV-associated neurocognitive disorders (HAND) will benefit from the antioxidant effects of glutathione supplementation. The potential effects of glutathione supplementation in patients with HAND are likely to differ based on the specific HIV-associated neurocognitive disease.

Immunopathology of Pulmonary Mycobacterium tuberculosis Infection in a Humanized Mouse Model.

Despite the availability of antibiotic therapy, tuberculosis (TB) is prevailing as a leading killer among human infectious diseases, which highlights the need for better intervention strategies to control TB. Several animal model systems, including mice, guinea pigs, rabbits, and non-human primates have been developed and explored to understand TB pathogenesis. Although each of these models contributes to our current understanding of host-Mycobacterium tuberculosis (Mtb) interactions, none of these models fully recapitulate the pathological spectrum of clinical TB seen in human patients. Recently, humanized mouse models are being developed to improvise the limitations associated with the standard mouse model of TB, including lack of necrotic caseation of granulomas, a pathological hallmark of TB in humans. However, the spatial immunopathology of pulmonary TB in humanized mice is not fully understood. In this study, using a novel humanized mouse model, we evaluated the spatial immunopathology of pulmonary Mtb infection with a low-dose inoculum. Humanized NOD/LtSscidIL2Rγ null mice containing human fetal liver, thymus, and hematopoietic CD34+ cells and treated with human cytokines were aerosol challenged to implant <50 pathogenic Mtb (low dose) in the lungs. At 2 and 4 weeks post infection, the tissue bacterial load, disease pathology, and spatial immunohistology were determined in the lungs, liver, spleen, and adipose tissue using bacteriological, histopathological, and immunohistochemical techniques. The results indicate that implantation of <50 bacteria can establish a progressive disease in the lungs that transmits to other tissues over time. The disease pathology in organs correspondingly increased with the bacterial load. A distinct spatial distribution of T cells, macrophages, and natural killer cells were noted in the lung granulomas. The kinetics of spatial immune cell distribution were consistent with the disease pathology in the lungs. Thus, the novel humanized model recapitulates several key features of human pulmonary TB granulomatous response and can be a useful preclinical tool to evaluate potential anti-TB drugs and vaccines.

Host Cell Death and Modulation of Immune Response against Mycobacterium tuberculosis Infection.

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis (TB), a prevalent infectious disease affecting populations worldwide. A classic trait of TB pathology is the formation of granulomas, which wall off the pathogen, via the innate and adaptive immune systems. Some key players involved include tumor necrosis factor-alpha (TNF-α), foamy macrophages, type I interferons (IFNs), and reactive oxygen species, which may also show overlap with cell death pathways. Additionally, host cell death is a primary method for combating and controlling Mtb within the body, a process which is influenced by both host and bacterial factors. These cell death modalities have distinct molecular mechanisms and pathways. Programmed cell death (PCD), encompassing apoptosis and autophagy, typically confers a protective response against Mtb by containing the bacteria within dead macrophages, facilitating their phagocytosis by uninfected or neighboring cells, whereas necrotic cell death benefits the pathogen, leading to the release of bacteria extracellularly. Apoptosis is triggered via intrinsic and extrinsic caspase-dependent pathways as well as caspase-independent pathways. Necrosis is induced via various pathways, including necroptosis, pyroptosis, and ferroptosis. Given the pivotal role of host cell death pathways in host defense against Mtb, therapeutic agents targeting cell death signaling have been investigated for TB treatment. This review provides an overview of the diverse mechanisms underlying Mtb-induced host cell death, examining their implications for host immunity. Furthermore, it discusses the potential of targeting host cell death pathways as therapeutic and preventive strategies against Mtb infection.

The Role of Glutathione in the Management of Cell-Mediated Immune Responses in Individuals with HIV.

Human immunodeficiency virus (HIV) is a major cause of death worldwide. Without appropriate antiretroviral therapy, the infection can develop into acquired immunodeficiency syndrome (AIDS). AIDS leads to the dysregulation of cell-mediated immunity resulting in increased susceptibility to opportunistic infections and excessive amounts of inflammatory cytokines. HIV-positive individuals also demonstrate diminished glutathione (GSH) levels which allows for increased viral replication and increased pro-inflammatory cytokine release, further contributing to the high rates of mortality seen in patients with HIV. Adequate GSH supplementation has reduced inflammation and slowed the decline of CD4+ T cell counts in HIV-positive individuals. We aim to review the current literature regarding the role of GSH in cell-mediated immune responses in individuals with HIV- and AIDS-defining illnesses.

Role of NF-κB during Mycobacterium tuberculosis Infection.

Mycobacterium tuberculosis (M. tb) causes tuberculosis infection in humans worldwide, especially among immunocompromised populations and areas of the world with insufficient funding for tuberculosis treatment. Specifically, M. tb is predominantly exhibited as a latent infection, which poses a greater risk of reactivation for infected individuals. It has been previously shown that M. tb infection requires pro-inflammatory and anti-inflammatory mediators to manage its associated granuloma formation via tumor necrosis factor-α (TNF-α), interleukin-12 (IL-12), interferon-γ (IFN-γ), and caseum formation via IL-10, respectively. Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) has been found to play a unique mediator role in providing a pro-inflammatory response to chronic inflammatory disease processes by promoting the activation of macrophages and the release of various cytokines such as IL-1, IL-6, IL-12, and TNF-α. NF-κB's role is especially interesting in its mechanism of assisting the immune system's defense against M. tb, wherein NF-κB induces IL-2 receptors (IL-2R) to decrease the immune response, but has also been shown to crucially assist in keeping a granuloma and bacterial load contained. In order to understand NF-κB's role in reducing M. tb infection, within this literature review we will discuss the dynamic interaction between M. tb and NF-κB, with a focus on the intracellular signaling pathways and the possible side effects of NF-κB inactivation on M. tb infection. Through a thorough review of these interactions, this review aims to highlight the role of NF-κB in M. tb infection for the purpose of better understanding the complex immune response to M. tb infection and to uncover further potential therapeutic methods.

Pathogenicity of Type I Interferons in Mycobacterium tuberculosis.

Tuberculosis (TB) is a leading cause of mortality due to infectious disease and rates have increased during the emergence of COVID-19, but many of the factors determining disease severity and progression remain unclear. Type I Interferons (IFNs) have diverse effector functions that regulate innate and adaptive immunity during infection with microorganisms. There is well-documented literature on type I IFNs providing host defense against viruses; however, in this review, we explore the growing body of work that indicates high levels of type I IFNs can have detrimental effects to a host fighting TB infection. We report findings that increased type I IFNs can affect alveolar macrophage and myeloid function, promote pathological neutrophil extracellular trap responses, inhibit production of protective prostaglandin 2, and promote cytosolic cyclic GMP synthase inflammation pathways, and discuss many other relevant findings.

Recent Developments in the Understanding of Immunity, Pathogenesis and Management of COVID-19.

Coronaviruses represent a diverse family of enveloped positive-sense single stranded RNA viruses. COVID-19, caused by Severe Acute Respiratory Syndrome Coronavirus-2, is a highly contagious respiratory disease transmissible mainly via close contact and respiratory droplets which can result in severe, life-threatening respiratory pathologies. It is understood that glutathione, a naturally occurring antioxidant known for its role in immune response and cellular detoxification, is the target of various proinflammatory cytokines and transcription factors resulting in the infection, replication, and production of reactive oxygen species. This leads to more severe symptoms of COVID-19 and increased susceptibility to other illnesses such as tuberculosis. The emergence of vaccines against COVID-19, usage of monoclonal antibodies as treatments for infection, and implementation of pharmaceutical drugs have been effective methods for preventing and treating symptoms. However, with the mutating nature of the virus, other treatment modalities have been in research. With its role in antiviral defense and immune response, glutathione has been heavily explored in regard to COVID-19. Glutathione has demonstrated protective effects on inflammation and downregulation of reactive oxygen species, thereby resulting in less severe symptoms of COVID-19 infection and warranting the discussion of glutathione as a treatment mechanism.

Mechanisms of Nausea and Vomiting: Current Knowledge and Recent Advances in Intracellular Emetic Signaling Systems.

Nausea and vomiting are common gastrointestinal complaints that can be triggered by diverse emetic stimuli through central and/or peripheral nervous systems. Both nausea and vomiting are considered as defense mechanisms when threatening toxins/drugs/bacteria/viruses/fungi enter the body either via the enteral (e.g., the gastrointestinal tract) or parenteral routes, including the blood, skin, and respiratory systems. While vomiting is the act of forceful removal of gastrointestinal contents, nausea is believed to be a subjective sensation that is more difficult to study in nonhuman species. In this review, the authors discuss the anatomical structures, neurotransmitters/mediators, and corresponding receptors, as well as intracellular emetic signaling pathways involved in the processes of nausea and vomiting in diverse animal models as well as humans. While blockade of emetic receptors in the prevention of vomiting is fairly well understood, the potential of new classes of antiemetics altering postreceptor signal transduction mechanisms is currently evolving, which is also reviewed. Finally, future directions within the field will be discussed in terms of important questions that remain to be resolved and advances in technology that may help provide potential answers.

The preclinical candidate indole-2-carboxamide improves immune responses to Mycobacterium tuberculosis infection in healthy subjects and individuals with type 2 diabetes.

A novel group of agents known as the indole-2-carboxamides (often referred to as indoleamides) have been shown to demonstrate high antimycobacterial activity. Studies have demonstrated that the best indoleamides possess desirable ADME/Tox properties, with less adverse effects and increased efficacy against both MDR-TB (multi-drug resistant TB) and XDR-TB (extensively drug-resistant TB). The primary mechanism of killing Mycobacterium tuberculosis (Mtb) by indoleamides is by disrupting the function of the essential mycolic acid transporter MmpL3 protein (Mycobacterial membrane protein Large 3). Therefore, targeting this essential mycobacterial transporter by small molecules opens new possibility for the development of novel and effective anti-TB agents. In the present study, we characterized the effects of indoleamides in altering the viability of Mtb in an in vitro granuloma model using immune cells derived from healthy subjects and those with type 2 diabetes mellitus (T2DM). Our results indicate that treatment with the best indoleamide 3 resulted in a significant reduction in the viability of Mtb in both THP-1 macrophages as well as in granulomas derived from healthy individuals and subjects with T2DM. Graphical Abstract.

A Role of Intracellular Toll-Like Receptors (3, 7, and 9) in Response to Mycobacterium tuberculosis and Co-Infection with HIV.

Mycobacterium tuberculosis (Mtb) is a highly infectious acid-fast bacillus and is known to cause tuberculosis (TB) in humans. It is a leading cause of death from a sole infectious agent, with an estimated 1.5 million deaths yearly worldwide, and up to one third of the world's population has been infected with TB. The virulence and susceptibility of Mtb are further amplified in the presence of Human Immunodeficiency Virus (HIV). Coinfection with Mtb and HIV forms a lethal combination. Previous studies had demonstrated the synergistic effects of Mtb and HIV, with one disease accelerating the disease progression of the other through multiple mechanisms, including the modulation of the immune response to these two pathogens. The response of the endosomal pattern recognition receptors to these two pathogens, specifically toll-like receptors (TLR)-3, -7, and -9, has not been elucidated, with some studies producing mixed results. This article seeks to review the roles of TLR-3, -7, and -9 in response to Mtb infection, as well as Mtb-HIV-coinfection via Toll-interleukin 1 receptor (TIR) domain-containing adaptor inducing INF-ß (TRIF)-dependent and myeloid differentiation factor 88 (MyD88)-dependent pathways.

Flavonoid Mixture Inhibits Mycobacterium tuberculosis Survival and Infectivity.

BACKGROUND: Flavonoids have been shown to exert anti-pathogenic potential, but few studies have investigated their effects on Mycobacterium tuberculosis (Mtb) infectivity. We hypothesized that a flavonoid mixture would have a favorable influence on cell death and the resolution of Mtb infection in THP-1 macrophages and in granulomas derived from both healthy participants and those with type 2 diabetes mellitus (T2DM). METHODS: THP-1 macrophages, and in vitro granulomas from healthy participants (N = 8) and individuals with T2DM (N = 5) were infected with Mtb. A mixed flavonoid supplement (MFS) at a concentration of 0.69 mg per ml was added as treatment to Mtb infected THP-1 macrophages and granulomas for 8 to 15 days. RESULTS: MFS treatment significantly reduced the intracellular Mtb survival, increased cell density, aggregation, and granuloma formation, and increased glutathione (GSH) levels. IL-12 and IFN-γ levels tended to be higher and IL-10 lower when Mtb infected THP-1 macrophages and granulomas obtained from healthy subjects were treated with MFS compared to control. CONCLUSIONS: MFS treatment exerted a strong influence against Mtb infectivity in THP-1 macrophages and in granulomas including antimycobacterial effects, GSH enrichment, cytokine regulation, and augmented granuloma formation. Our data support the strategy of increased flavonoid intake for managing tuberculosis.

Characterizing the Effects of Glutathione as an Immunoadjuvant in the Treatment of Tuberculosis.

Mycobacterium tuberculosis is the etiological agent that is responsible for causing tuberculosis (TB), which continues to affect millions of people worldwide, and the rate of resistance of M. tuberculosis to antibiotics is ever increasing. We tested the synergistic effects of N-acetyl cysteine (NAC; the precursor molecule for the synthesis of glutathione [GSH]) and individual first-line antibiotics typically given for the treatment of TB, such as isoniazid (INH), rifampin (RIF), ethambutol (EMB), and pyrazinamide (PZA), to improve the ability of macrophages to control intracellular M. tuberculosis infection. GSH, a pleiotropic antioxidant molecule, has previously been shown to display both antimycobacterial and immune-enhancing effects. Our results indicate that there was not only an increase in beneficial immunomodulatory effects but also a greater reduction in the intracellular viability of M. tuberculosis when macrophages were treated with the combination of antibiotics (INH, RIF, EMB, or PZA) and NAC.

Glutathione and infection.

BACKGROUND: The tripeptide γ-glutamylcysteinylglycine or glutathione (GSH) has demonstrated protective abilities against the detrimental effects of oxidative stress within the human body, as well as protection against infection by exogenous microbial organisms. SCOPE OF REVIEW: In this review we describe how GSH works to modulate the behavior of many cells including the cells of the immune system, augmenting the innate and the adaptive immunity as well as conferring protection against microbial, viral and parasitic infections. This article unveils the direct antimicrobial effects of GSH in controlling Mycobacterium tuberculosis (M. tb) infection within macrophages. In addition, we summarize the effects of GSH in enhancing the functional activity of various immune cells such as natural killer (NK) cells and T cells resulting in inhibition in the growth of M. tb inside monocytes and macrophages. Most importantly we correlate the decreased GSH levels previously observed in individuals with pulmonary tuberculosis (TB) with an increase in the levels of pro-inflammatory cytokines which aid in the growth of M. tb. MAJOR CONCLUSIONS: In conclusion, this review provides detailed information on the protective integral effects of GSH along with its therapeutic effects as they relate to the human immune system and health. GENERAL SIGNIFICANCE: It is important to note that the increases in the levels of pro-inflammatory cytokines are not only detrimental to the host due to the sequel that follow such as fever and cachexia, but also due to the alteration in the functions of immune cells. The additional protective effects of GSH are evident after sequel that follows the depletion of this antioxidant. This is evident in a condition such as Cystic Fibrosis (CF) where an increased oxidant burden inhibits the clearance of the affecting organism and results in oxidant-induced anti-protease inhibition. GSH has a similar protective effect in protozoans as it does in human cells. Thus GSH is integral to the survival of some of the protozoans because some protozoans utilize the compound trypanothione [T(SH)2] as their main antioxidant. T(SH)2 in turn requires GSH for its production. Hence a decrease in the levels of GSH (by a known inhibitor such as buthionine sulfoximine [BSO] can have adverse effects of the protozoan parasites. This article is part of a Special Issue entitled Cellular functions of glutathione.

A Review of Eales' Disease and Mycobacterium tuberculosis.

Eales' Disease is an idiopathic peripheral retinal vasculopathy first described by British ophthalmologist Henry Eales in 1880. Most prevalent in healthy young males, Eales' Disease often presents with symptoms of sudden blurry or decreased vision and floaters. Although no clear, standardized stage of the disease exists, it progresses through three overlapping phases-peripheral periphlebitis, ischemic capillary ischemia, and retinal neovascularization. The etiology of Eales' Disease is unknown and appears to be multifactorial, but post-TB hypersensitivity to tuberculoprotein and M. tuberculosis DNA is the most potential cause in the etiology of Eales' Disease. With a thorough examination of the clinical presentation and diagnosis of Eales' Disease-incorporating the latest clinical findings related to the condition-the investigation for Eales' Disease extends to explore recent potential connections with other ocular conditions or possible cofactors, such as glaucoma, uncontrolled diabetes, drug abuse, or inherited medical conditions. Moreover, focusing on critical insights into the treatment of Eales' Disease across its various stages of progression, the overarching goal of the paper is to refine and suggest possible future diagnostic and therapeutic strategies. Widening our understanding of pathophysiology and utilizing various treatment options for individual patients holds immense potential for advancing ocular medicine and optimizing patient care for people with this disease with unknown pathophysiology.

HIV-TB Coinfection: Current Therapeutic Approaches and Drug Interactions.

The co-occurrence of human immunodeficiency virus (HIV) and tuberculosis (TB) infection poses a significant global health challenge. Treatment of HIV and TB co-infection often necessitates combination therapy involving antiretroviral therapy (ART) for HIV and anti-TB medications, which introduces the potential for drug-drug interactions (DDIs). These interactions can significantly impact treatment outcomes, the efficacy of treatment, safety, and overall patient well-being. This review aims to provide a comprehensive analysis of the DDIs between anti-HIV and anti-TB drugs as well as potential adverse effects resulting from the concomitant use of these medications. Furthermore, such findings may be used to develop personalized therapeutic strategies, dose adjustments, or alternative drug choices to minimize the risk of adverse outcomes and ensure the effective management of HIV and TB co-infection.

Dysregulation of Gamma Delta T-Cells, CD8+ T Cells, CD4+ T Cells, and Natural Killer Cells in Brain Pathology: Understanding HIV-Induced Impairment and Exploring Targeted GSH Therapy.

This review comprehensively explores the dysregulation of Gamma Delta T-cells, CD8+ T Cells, and Natural Killer T Cells in the context of Human Immunodeficiency Virus (HIV) infection and its implications for brain pathology. It encompasses an overview of the HIV disease process, immune cell dysregulation, association with neurological diseases, and the critical role of Glutathione (GSH) in T-cell function. The alterations in Gamma Delta T-cells during chronic infection, the intricate dynamics of Vδ1 and Vδ2 subsets, and the potential of Vγ9Vδ2 T cells in inhibiting HIV replication are discussed. Additionally, the review addresses the exhaustion, impaired cytotoxicity, and premature senescence of CD8+ T cells, as well as the dysregulation of Natural Killer Cells (NKCs) and their impact on overall immune system activity. Furthermore, it examines the role of Gamma Delta (γδ) T-cells in brain injuries, infections, and tumors and highlights the therapeutic implications of elevated GSH levels in promoting a T helper 1 (Th1) immune response. However, HIV-infected patients with decreased GSH exhibit a T helper 2 (Th2) bias, compromising protection against intracellular pathogens. Finally, the review discusses studies in murine models demonstrating the impact of GSH levels on immune responses and underscores the therapeutic potential of targeting GSH to enhance immunity in HIV patients. Overall, this review provides valuable insights into the complex interplay between immune dysregulation, GSH levels, and HIV-associated brain pathology, offering insights into potential therapeutic avenues for mitigating immune compromise and neurological impairments in HIV patients.

Immune Responses to Mycobacterium tuberculosis Infection in the Liver of Diabetic Mice.

Individuals with uncontrolled diabetes are highly susceptible to tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tb) infection. Novel treatments for TB are needed to address the increased antibiotic resistance and hepatoxicity. Previous studies showed that the administration of liposomal glutathione (L-GSH) can mitigate oxidative stress, bolster a granulomatous response, and diminish the M. tb burden in the lungs of M. tb-infected mice. Nonetheless, the impact of combining L-GSH with conventional TB treatment (RIF) on the cytokine levels and granuloma formation in the livers of diabetic mice remains unexplored. In this study, we evaluated hepatic cytokine profiles, GSH, and tissue pathologies in untreated and L-GSH, RIF, and L-GSH+RIF treated diabetic (db/db) M. tb-infected mice. Our results indicate that treatment of M. tb-infected db/db mice with L-GSH+RIF caused modulation in the levels of pro-inflammatory cytokines and GSH in the liver and mitigation in the granuloma size in hepatic tissue. Supplementation with L-GSH+RIF led to a decrease in the M. tb burden by mitigating oxidative stress, promoting the production of pro-inflammatory cytokines, and restoring the cytokine balance. These findings highlight the potential of L-GSH+RIF combination therapy for addressing active EPTB, offering valuable insights into innovative treatments for M. tb infections.

TB and HIV induced immunosenescence: where do vaccines play a role?

This paper tackles the complex interplay between Human Immunodeficiency virus (HIV-1) and Mycobacterium tuberculosis (M. tuberculosis) infections, particularly their contribution to immunosenescence, the age-related decline in immune function. Using the current literature, we discuss the immunological mechanisms behind TB and HIV-induced immunosenescence and critically evaluate the BCG (Bacillus Calmette-Guérin) vaccine's role. Both HIV-1 and M. tuberculosis demonstrably accelerate immunosenescence: M. tuberculosis through DNA modification and heightened inflammation, and HIV-1 through chronic immune activation and T cell production compromise. HIV-1 and M. tuberculosis co-infection further hastens immunosenescence by affecting T cell differentiation, underscoring the need for prevention and treatment. Furthermore, the use of the BCG tuberculosis vaccine is contraindicated in patients who are HIV positive and there is a lack of investigation regarding the use of this vaccine in patients who develop HIV co-infection with possible immunosenescence. As HIV does not currently have a vaccine, we focus our review more so on the BCG vaccine response as a result of immunosenescence. We found that there are overall limitations with the BCG vaccine, one of which is that it cannot necessarily prevent re-occurrence of infection due to effects of immunosenescence or protect the elderly due to this reason. Overall, there is conflicting evidence to show the vaccine's usage due to factors involving its production and administration. Further research into developing a vaccine for HIV and improving the BCG vaccine is warranted to expand scientific understanding for public health and beyond.

Mycobacterial Endocarditis, A Rare Form of Infective Endocarditis.

This research project delves into the multifaceted dynamics of Mycobacterium tuberculosis (M.tb) endocarditis, a significant yet uncommon manifestation of tuberculosis (TB). Beginning with an overview of M.tb and the global challenges posed by TB, we navigate through the bacterium's evolution, transmission modes, and the intricate host immune response. The pathology and pathophysiology of M.tb endocarditis are explored, emphasizing its complexities and the host's efforts to contain the pathogen. The study extends to atypical mycobacterial endocarditis, highlighting the emergence of species like M.chimaera, M.fortuitum, and M.chelonae, with a focus on their association with life-threatening mycobacterial endocarditis. Clinical presentations and complications of M.tb endocarditis are detailed, addressing challenges in diagnosis, drug-resistant, co-infections with Human Immunodeficiency Virus (HIV), and potential sepsis. The research underscores the need for a deeper understanding of M.tb endocarditis to enhance prevention, diagnosis, and treatment strategies. Examining the genetic and environmental factors influencing M.tb endocarditis, the study discusses the interplay of immune-related genes, environmental conditions, and predispositions contributing to infection susceptibility. Despite challenges in treatment due to its rarity, the research highlights current protocols, surgical interventions, and promising pharmaceutical developments. Lastly, unraveling these intricate factors is crucial for refining strategies and conducting large-scale trials to address this global health threat effectively.