Tuberculosis, BCG Vaccination and COVID-19: Are They Connected?

2022 ◽  
Vol 22 ◽  
Author(s):  
Kellen Christina Malheiros Borges ◽  
Adeliane Castro da Costa ◽  
Lília Cristina de Souza Barbosa ◽  
Kaio Mota Ribeiro ◽  
Laura Raniere Borges dos Anjos ◽  
...  
Keyword(s):  
Immune Response ◽  
Viral Infections ◽  
Preventive Measure ◽  
Cross Protection ◽  
Innate Immune ◽  
Bcg Vaccine ◽  
Bacillus Calmette Guerin ◽  
Immunomodulatory Properties ◽  
Immunological Protection ◽  
Cellular Immune

Abstract: Evidence from multiple scientific studies suggests that the Bacillus Calmette–Guérin (BCG) vaccine, widely used worldwide as a preventive measure against tuberculosis, also offers cross-protection against other pathogens. This review aimed to gather data from research that studied the mechanisms involved in the immunological protection induced by the BCG vaccine, which may be important in the control of viral infections, such as COVID-19. Through a literature review, we compiled information about the different BCG strains used worldwide, as well as the responses and protection elicited by them. We commented on the mechanisms of immune response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and we discussed the possibility of cross-protection of different BCG strains on the control of COVID-19. Due to the immunomodulatory properties of BCG, some BCG strains were able to induce an effective cellular immune response and, through epigenetic modifications, activate cells of the innate immune system, such as monocytes, macrophages and natural killer cells, which are crucial for the control of viral infections. Although several vaccines have already been developed and used in an attempt to control the COVID-19 pandemic, some BCG vaccine strains may help stimulate the basal defences against these pathogens and can be used as additional defences in this and future pandemics.

scholarly journals IFN-α Boosting of Mycobacterium bovis Bacillus Calmette Güerin-Vaccine Promoted Th1 Type Cellular Response and Protection against M. tuberculosis Infection

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
C. E. Rivas-Santiago ◽  
G. G. Guerrero
Keyword(s):  
Immune Response ◽  
Mycobacterium Bovis ◽  
Cellular Immune Response ◽  
Cellular Response ◽  
Bacterial Load ◽  
Bcg Vaccine ◽  
Type I ◽  
Bacillus Calmette Guerin ◽  
Type I Ifns ◽  
Cellular Immune

The role of type I IFNs in the pathogenesis and control of mycobacterial infection is still controversial. It has been reported that type I IFNs exacerbated M. tuberculosis infection through hampering Th1 type cellular immune response. However, under certain conditions they can act as natural immune adjuvants for commercial vaccines. At this point, we have reported recently that successive IFN-alpha boosting of Mycobacterium bovis Bacillus Calmette Güerin (BCG) vaccinated mice protected adult mice from intradermal M. lepraemurium infection and a difference in iNOS was observed. In the present work, we have found that intramuscular IFN-α boosting of Mycobacterium bovis Bacillus Calmette Güerin (BCG) vaccine, either in vitro (human cell line or macrophages derived from PBMC) or in vivo (aerosol mouse model of MTb infection), promoted mostly the development of specific anti-antimycobacterial Th1 type cytokines (IFN-γ; IL-12, TNF-alpha, and IL-17; IL1β) while bacterial load reduction (0.9 logs versus PBS or BCG vaccine) was observed. These findings indicate that, under the experimental settings reported here, interferon alpha can drive or affect the TH cellular immune response in favour of BCG-inducing immunity against M. tuberculosis infection.

scholarly journals The Respiratory Commensal Bacterium Dolosigranulum pigrum 040417 Improves the Innate Immune Response to Streptococcus pneumoniae

2021 ◽  
Vol 9 (6) ◽  
pp. 1324
Author(s):  
Fernanda Raya Tonetti ◽  
Mikado Tomokiyo ◽  
Ramiro Ortiz Moyano ◽  
Sandra Quilodrán-Vega ◽  
Hikari Yamamuro ◽  
...  
Keyword(s):  
Immune Response ◽  
Streptococcus Pneumoniae ◽  
Innate Immune Response ◽  
Pneumococcal Infection ◽  
Innate Immune ◽  
Nasal Administration ◽  
Commensal Bacterium ◽  
Beneficial Effects ◽  
Immunological Mechanisms ◽  
Immunomodulatory Properties

Previously, we demonstrated that the nasal administration of Dolosigranulum pigrum 040417 differentially modulated the respiratory innate immune response triggered by the activation of Toll-like receptor 2 in infant mice. In this work, we aimed to evaluate the beneficial effects of D. pigrum 040417 in the context of Streptococcus pneumoniae infection and characterize the role of alveolar macrophages (AMs) in the immunomodulatory properties of this respiratory commensal bacterium. The nasal administration of D. pigrum 040417 to infant mice significantly increased their resistance to pneumococcal infection, differentially modulated respiratory cytokines production, and reduced lung injuries. These effects were associated to the ability of the 040417 strain to modulate AMs function. Depletion of AMs significantly reduced the capacity of the 040417 strain to improve both the reduction of pathogen loads and the protection against lung tissue damage. We also demonstrated that the immunomodulatory properties of D. pigrum are strain-specific, as D. pigrum 030918 was not able to modulate respiratory immunity or to increase the resistance of mice to an S. pneumoniae infection. These findings enhanced our knowledge regarding the immunological mechanisms involved in modulation of respiratory immunity induced by beneficial respiratory commensal bacteria and suggested that particular strains could be used as next-generation probiotics.

Toll-like receptor polymorphisms and susceptibility to human disease

2008 ◽  
Vol 114 (5) ◽  
pp. 347-360 ◽  
Author(s):  
E. Ann Misch ◽  
Thomas R. Hawn
Keyword(s):  
Immune Response ◽  
Disease Susceptibility ◽  
Innate Immune ◽  
Toll Like Receptor ◽  
Genetic Studies ◽  
The Past ◽  
Molecular Studies ◽  
Cellular Immune ◽  
Lines Of Evidence

Although several lines of evidence suggest that variation in human inflammation is genetically controlled, the genes which regulate these responses are largely unknown. TLRs (Toll-like receptors) mediate recognition of microbes, regulate activation of the innate immune response and influence the formation of adaptive immunity. Cellular and molecular studies over the past several years have identified a number of common TLR polymorphisms that modify the cellular immune response and production of cytokines in vitro. In addition, human genetic studies suggest that some of these polymorphisms are associated with susceptibility to a spectrum of diseases. In this review, we summarize studies of common TLR polymorphisms and how this work is beginning to illuminate the influence of human variation on inflammation and disease susceptibility.

scholarly journals COVID-19, T Cells, Cytokines and Immunotherapy: Review

2021 ◽  
pp. 70-82
Author(s):  
Nesrin I. Tarbiah
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Viral Infections ◽  
Cytotoxic T Cells ◽  
Clinical Findings ◽  
Global Pandemic ◽  
Significant Step ◽  
Novel Coronavirus ◽  
Cellular Immune ◽  
Cell Expression

In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus (COVID-19), materialized in the city of Wuhan and quickly spread to form a global pandemic. An essential role in the immune system is undertaken by lymphocytes, which defend against bacteria, viruses, fungi, and parasites. Previous study found that very severe COVID-19 patients had suppression of the immune response enabling the virus to spread and cause more damage. This was evident by the changes in their white blood cell and lymphocyte count. Early clinical findings suggest that those suffering from severe COVID-19 have reduced numbers of lymphocytes, monocytes, and other granulocytes. One of the most efficient responses for a variety of viral infections is cellular immune response activation, especially via T cells. Viruses can be eliminated by T cytotoxic (CD8+) (Tc) in the host body, these secrete a variety of molecules, including interferons (IFNs), granzyme, and perforin. T helper (CD4+) (Th) cells help by assisting cytotoxic T cells and B cells to eliminate viral infection. CD8+ and CD4+ work together in a coordinated immune response with other constituents to primarily resolve acute viral infections, and after to produce protection against any reinfection. Also, COVID-19 causes dramatic changes in cytokine profiles and serological markers. Therefore, the subsets of immune cells and the level of the pro-inflammatory cytokines are crucial evidence to determine the severity of COVID-19. The disease severity has already been proved to be associated with the disruption in the proinflammatory chemokine response, this eventually leads to a cytokine storm and progression of cytokines release syndrome (CRS). This review aimed to demonstrate a full understanding of the alterations to the immune response by determining the T-cell expression and cytokine levels against the pathological processes of COVID-19, which can be a significant step in early treatment and diagnosis of this disease, in reduction of COVID-19 mortality cases, and to emphasize the most recent and current studies to try to identify new immuno-therapeutics for COVID-19.  

scholarly journals Principals of innate and adaptive immunity. Immunity to microbes & fundamental concepts in immunology

2021 ◽  
Vol 10 (3) ◽  
pp. 188-197
Author(s):  
Andrew Kiboneka
Keyword(s):  
Immune Response ◽  
Immune Cells ◽  
Chemokine Receptors ◽  
The Body ◽  
Innate Immune ◽  
Lymphoid Cells ◽  
Biologically Active ◽  
Surface Receptors ◽  
Bacterial Surfaces ◽  
Cellular Immune

Microorganisms such as bacteria that penetrate the epithelial surfaces of the body for the first time are met immediately by cells and molecules that can mount an innate immune response. Phagocytic macrophages conduct the defense against bacteria by means of surface receptors that are able to recognize and bind common constituents of many bacterial surfaces. Bacterial molecules binding to these receptors trigger the macrophage to engulf the bacterium and also induce the secretion of biologically active molecules. Activated macrophages secrete cytokines, which are defined as proteins released by cells that affect the behavior of other cells that bear receptors for them. They also release proteins known as chemokines that attract cells with chemokine receptors such as neutrophils and monocytes from the bloodstream. Macrophages in response to bacterial constituents initiate the process known as inflammation. Antigen-presenting cells (APCs) are a heterogeneous group of immune cells that mediate the cellular immune response by processing and presenting antigens for recognition by certain lymphocytes such as T cells. Classical APCs include dendritic cells, macrophages, Langerhans cells and B cells. Innate lymphoid cells (ILCs) are immune cells that belong to the lymphoid lineage but do not express antigen-specific receptors. These cells have important functions in innate immune responses to infectious microorganisms and in the regulation of homeostasis and inflammation.

scholarly journals BCG as an adjunct or alternative vaccine to prevent COVID-19?

2020 ◽  
Vol 27 (7) ◽  
Author(s):  
Chien-Hsiang Weng ◽  
Philip A Chan
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Bcg Vaccine ◽  
Specific Immunity

BCG vaccine may enhance the innate immune response as well as induce a specific immunity against SARS-CoV-2, which may potentially be associated with reduced severity of COVID-19, and may or may not necessarily be protective against SARS-CoV-2 infection. The effect from BCG vaccine was observed even decades after the vaccination.

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