The impact of aging-induced gut microbiome dysbiosis on dendritic cells and lung diseases.

Aging is an inevitable natural process that impacts every individual, and understanding its effect on the gut microbiome and dendritic cell (DC) functionality in elderly subjects is crucial. DCs are vital antigen-presenting cells (APCs) that orchestrate the immune response, maintaining immune tolerance to self-antigens and bridging innate and adaptive immunity. With aging, there is a shift toward nonspecific innate immunity, resulting in a decline in adaptive immune responses. This alteration raises significant concerns about managing the health of an elderly population. However, the precise impact of aging and microbiome changes on DC function and their implications in lung-associated diseases remain relatively understudied. To illuminate this subject, we will discuss recent advancements in understanding the connections between aging, gut dysbiosis, DCs, and lung diseases. Emphasizing the key concepts linking age-related gut microbiome changes and DC functions, we will focus on their relevance to overall health and immune response in elderly individuals. This article aims to improve our understanding of the intricate relationship between aging, gut microbiome, and DCs, potentially benefiting the management of age-associated diseases and promoting healthy aging.

Influence of chronic administration of morphine and its withdrawal on the behaviour of zebrafish.

Morphine is a potent analgesic opiate used to treat chronic pain, mostly in cancer patients. In addition, it is widely used as a drug of abuse. Due to the continuous rise of morphine-associated addiction, there is an urgent need to develop pre-clinical animal models to understand the behavioural pattern of drug dependence and its withdrawal. Recently, the experimental use of zebrafish has attained significance in behavioural neuroscience studies. The literature on zebrafish is conflicting with regard to morphine withdrawal symptoms. Unfortunately, no single model provides comprehensive details to evaluate zebrafish behaviour on opiate exposure. Further, the current models have various limitations, such as short duration, complexity of phenotypes, intricate quantification, and difficulty in studying withdrawal symptoms. Consequently, a firm standardization of the protocol to understand the influence of opiates on physiological and psychological behaviours is required. In this study, we have tried to overcome the shortcomings associated with the existing models and to optimize the protocols involving an array of parameters. We observed that the administration of morphine caused a significant increase in zebrafish behavioural patterns of spiral movements, circular movements, erratic movements, upper transitions, water surface transitions, wall licking, wall licking with upper transitions, wall licking with lower transitions, absolute angle changes, and time spent in the upper compartment. A decline in the freezing bouts and time spent in the lower compartment were noticed. In essence, this study offers a zebrafish model to comprehensively examine changes in behaviour of animals on opiate dependence and its withdrawal. The present study also reported that in zebrafish, the influence of chronic exposure of morphine modulates key gene targets involved in behaviour, neuroinflammation, and autophagy, which directly or indirectly are associated with morphine addiction in a chronic morphine model.

Targeting dendritic cells with TLR-2 ligand-coated nanoparticles loaded with Mycobacterium tuberculosis epitope induce antituberculosis immunity.

Novel vaccination strategies are crucial to efficiently control tuberculosis, as proposed by the World Health Organization under its flagship program "End TB Strategy." However, the emergence of drug-resistant strains of Mycobacterium tuberculosis (Mtb), particularly in those coinfected with HIV-AIDS, constitutes a major impediment to achieving this goal. We report here a novel vaccination strategy that involves synthesizing a formulation of an immunodominant peptide derived from the Acr1 protein of Mtb. This nanoformulation in addition displayed on the surface a toll-like receptor-2 ligand to offer to target dendritic cells (DCs). Our results showed an efficient uptake of such a concoction by DCs in a predominantly toll-like receptor-2-dependent pathway. These DCs produced elevated levels of nitric oxide, proinflammatory cytokines interleukin-6, interleukin-12, and tumor necrosis factor-α, and upregulated the surface expression of major histocompatibility complex class II molecules as well as costimulatory molecules such as CD80 and CD86. Animals injected with such a vaccine mounted a significantly higher response of effector and memory Th1 cells and Th17 cells. Furthermore, we noticed a reduction in the bacterial load in the lungs of animals challenged with aerosolized live Mtb. Therefore, our findings indicated that the described vaccine triggered protective anti-Mtb immunity to control the tuberculosis infection.

Fiction and Facts about BCG Imparting Trained Immunity against COVID-19.

The Bacille Calmette-Guérin or BCG vaccine, the only vaccine available against Mycobacterium tuberculosis can induce a marked Th1 polarization of T-cells, characterized by the antigen-specific secretion of IFN-γ and enhanced antiviral response. A number of studies have supported the concept of protection by non-specific boosting of immunity by BCG and other microbes. BCG is a well-known example of a trained immunity inducer since it imparts 'non-specific heterologous' immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the recent pandemic. SARS-CoV-2 continues to inflict an unabated surge in morbidity and mortality around the world. There is an urgent need to devise and develop alternate strategies to bolster host immunity against the coronavirus disease of 2019 (COVID-19) and its continuously emerging variants. Several vaccines have been developed recently against COVID-19, but the data on their protective efficacy remains doubtful. Therefore, urgent strategies are required to enhance system immunity to adequately defend against newly emerging infections. The concept of trained immunity may play a cardinal role in protection against COVID-19. The ability of trained immunity-based vaccines is to promote heterologous immune responses beyond their specific antigens, which may notably help in defending against an emergency situation such as COVID-19 when the protective ability of vaccines is suspicious. A growing body of evidence points towards the beneficial non-specific boosting of immune responses by BCG or other microbes, which may protect against COVID-19. Clinical trials are underway to consider the efficacy of BCG vaccination against SARS-CoV-2 on healthcare workers and the elderly population. In this review, we will discuss the role of BCG in eliciting trained immunity and the possible limitations and challenges in controlling COVID-19 and future pandemics.

Metachronous second primary malignancy in head and neck cancer patients: is five years of follow-up sufficient?

OBJECTIVES: The aim of this study was to determine the incidence and characteristics of second primary malignancy (SPM) in patients with head and neck squamous cell carcinoma treated at a tertiary care hospital. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 221 patients who underwent surgery with or without adjuvant treatment for head and neck cancer from 2000 to 2002. Data of age, sex, risk factors, sites of primary and SPM, TNM stage of primary tumor, incidence of SPM, and survival were collected from medical charts. RESULTS: Eighteen patients developed SPM during a median follow-up of 67 months, with an overall incidence of 8.14%. In addition, 77.7% of SPMs occurred in the oral cavity, followed by 11% in the lungs. The 5-year overall survival after the diagnosis of SPM in the head or neck was 70%, compared to 30% for SPM in other body regions. CONCLUSION: Considering a high incidence of SPM, i.e., 8.14%, in a mean follow-up period of 67 months suggests the need for long-term follow-up. Since treatment of SPM has shown an acceptable survival rate, early detection and curative therapy should be emphasized.