scholarly journals Cytotoxicity and Secretion of Gamma Interferon Are Carried Out by Distinct CD8 T Cells during Mycobacterium tuberculosis Infection

2009 ◽  
Vol 77 (10) ◽  
pp. 4621-4630 ◽  
Author(s):  
Thorbjorg Einarsdottir ◽  
Euan Lockhart ◽  
JoAnne L. Flynn
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
Cd8 T Cells ◽  
Gamma Interferon ◽  
Mycobacterium Tuberculosis Infection ◽  
Memory Cd8 T Cells ◽  
Ifn Γ ◽  
Sterilizing Immunity

ABSTRACT The host immune response is generally sufficient to contain Mycobacterium tuberculosis infection. It does not, however, efficiently prevent subsequent infection with M. tuberculosis or provide sterilizing immunity. While the understanding of the immune response generated against this pathogen is incomplete, improvements have been achieved due to advances in immunological tools. In this study, we analyzed the multifunctional nature of primary and memory CD8 T-cell responses generated during murine M. tuberculosis infection. We generated a recombinant M. tuberculosis strain expressing ovalbumin (OVA) epitopes in order to expand the peptides for the detection of CD8 T cells during M. tuberculosis infection and enable us to use OVA-specific reagents. Our results indicate that the majority of M. tuberculosis-specific CD8 T cells are limited to either cytotoxicity or the secretion of gamma interferon (IFN-γ), with cytotoxicity being far more prevalent than IFN-γ secretion. Memory CD8 T cells responded earlier and reached higher levels in the lungs than naïve CD8 T cells, as was expected. They were, however, less cytotoxic and secreted less IFN-γ than newly primed CD8 T cells, suggesting that one factor contributing to bacterial persistence and lack of sterilizing immunity may be the low quality of memory cells that are generated.

scholarly journals CD8 T Cells in Old Mice Contribute to the Innate Immune Response to Mycobacterium tuberculosis via Interleukin-12p70-Dependent and Antigen-Independent Production of Gamma Interferon

2009 ◽  
Vol 77 (8) ◽  
pp. 3355-3363 ◽  
Author(s):  
Bridget Vesosky ◽  
Erin K. Rottinghaus ◽  
Craig Davis ◽  
Joanne Turner
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
Cd8 T Cells ◽  
The Elderly ◽  
Gamma Interferon ◽  
Ifn Γ ◽  
Aerosol Infection ◽  
Old Mice

ABSTRACT Elderly individuals have increased morbidity and mortality associated with infectious diseases due in part to the progressive age-associated decline in immune function. Despite this, the old mouse model of Mycobacterium tuberculosis infection has revealed a CD8- and gamma interferon (IFN-γ)-dependent early resistance to infection. In this study, we investigated the mechanism by which CD8 T cells from old mice contributed to the early immune response to M. tuberculosis. Following a low-dose aerosol infection with M. tuberculosis, CD8 T cells were identified as being a dominant source of IFN-γ expression in the lungs of old mice early after infection, before the typical onset of antigen-specific immunity. In addition, M. tuberculosis-induced IFN-γ production by CD8 T cells isolated from naïve old mice was major histocompatibility complex class I independent but was dependent on interleukin-12p70, confirming an innate role of CD8 T cells during M. tuberculosis infection. Moreover, the ability of CD8 T cells from old mice to produce increased innate IFN-γ levels in response to M. tuberculosis infection was defined as a unique function of CD8 T cells from old mice and not the aged lung environment. Finally, we have identified increased expression of SET as being one possible mechanism by which CD8 T cells from old mice produce enhanced levels of IFN-γ. Additional characterizations of the signaling events that lead to enhanced innate IFN-γ production by CD8 T cells in old mice may lead to novel strategies to further enhance or perpetuate beneficial immune responses in the elderly.

scholarly journals Memory CD8+ T Cells Provide Innate Immune Protection against Listeria monocytogenes in the Absence of Cognate Antigen

2003 ◽  
Vol 198 (10) ◽  
pp. 1583-1593 ◽  
Author(s):  
Rance E. Berg ◽  
Emily Crossley ◽  
Sean Murray ◽  
James Forman
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Listeria Monocytogenes ◽  
Innate Immune Response ◽  
Cd8 T Cells ◽  
Primary Source ◽  
Innate Immune ◽  
Memory Cd8 T Cells ◽  
Cognate Antigen ◽  
Ifn Γ

Interferon (IFN)-γ plays an important role in the innate immune response against intracellular bacterial pathogens. It is commonly thought that natural killer cells are the primary source of this cytokine that is involved in activating antibacterial effects in infected cells and polarizing CD4+ T cells toward the Th1 subset. However, here we show that both effector and memory CD8+ T cells have the potential to secrete IFN-γ in response to interleukin (IL)-12 and IL-18 in the absence of cognate antigen. We demonstrate that memory CD8+ T cells specific for the ovalbumin protein secrete IFN-γ rapidly after infection with wild-type Listeria monocytogenes (LM). Furthermore, small numbers of ovalbumin-specific, memory CD8+ T cells can reduce spleen and liver bacterial counts in IFN-γ–deficient mice 3 d after LM infection. Up-regulation of the receptors for IL-12 and IL-18 provides a mechanism for the ability of memory CD8+ T cells to respond in this antigen nonspecific manner. Thus, CD8+ T cells play an important role in the innate immune response against intracellular pathogens by rapidly secreting IFN-γ in response to IL-12 and IL-18.

scholarly journals Mycobacterium bovis BCG-Specific Th17 Cells Confer Partial Protection against Mycobacterium tuberculosis Infection in the Absence of Gamma Interferon

2010 ◽  
Vol 78 (10) ◽  
pp. 4187-4194 ◽  
Author(s):  
Teresa M. Wozniak ◽  
Bernadette M. Saunders ◽  
Anthony A. Ryan ◽  
Warwick J. Britton
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
Th17 Cells ◽  
Protective Immunity ◽  
Bacterial Load ◽  
Gamma Interferon ◽  
Interleukin 17 ◽  
Mycobacterium Tuberculosis Infection ◽  
Significant Prolongation ◽  
Ifn Γ

ABSTRACT Protective immunity against tuberculosis (TB) requires the integrated response of a network of lymphocytes. Both gamma interferon (IFN-γ)- and interleukin 17 (IL-17)-secreting CD4+ T cells have been identified in subjects with latent TB infection and during experimental Mycobacterium tuberculosis infection, but the contribution of Th17 cells to protective immunity is unclear. To examine their protective effects in vivo, we transferred mycobacterium-specific IL-17- and IFN-γ-secreting CD4+ T cells isolated from M. tuberculosis BCG-immunized IL-12p40−/− and IFN-γ−/− or wild-type mice, respectively, into M. tuberculosis-infected IL-12p40−/− or RAG−/− mice. In the absence of IL-12 and IL-23, neither IL-17-secreting (Th17) nor IFN-γ-secreting (Th1) BCG-specific T cells expanded or provided protection against M. tuberculosis. In RAG−/− recipients with an intact IL-12/IL-23 axis, both Th17 and Th1 cells were activated and induced significant protection against M. tuberculosis. The reduction in the bacterial load following transfer of IFN-γ−/− Th17 cells was associated with significant prolongation of survival compared to recipients of naïve IFN-γ−/− T cells. This effect was at the cost of an increased inflammatory infiltrate characterized by an excess of neutrophils. Therefore, Th17 cells can provide IFN-γ-independent protection against M. tuberculosis, and this effect may contribute to the early control of M. tuberculosis infection.

scholarly journals The effect of Kefir on The Immune Response of Healthy Volunteers In Vitro

2017 ◽  
Vol 3 (2) ◽  
pp. 28
Author(s):  
Desie Dwi Wisudanti
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Immune Responses ◽  
Healthy Volunteers ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Fermented Milk ◽  
Bioactive Components ◽  
Ifn Γ

Kefir is a functional foodstuff of probiotics, made from fermented milk with kefir grains containing various types of beneficial bacteria and yeast. There have been many studies on the effects of oral kefir on the immune system, but few studies have shown the effect of bioactive components from kefir (peptides and exopolysaccharides/ kefiran), on immune responses. The purpose of this study was to prove the effect of kefir supernatant from milk goat on healthy immune volunteer response in vitro. The study was conducted on 15 healthy volunteers, then isolated PBMC from whole blood, then divided into 5 groups (K-, P1, P2, P3 and P4) before culture was done for 4 days. The harvested cells from culture were examined for the percentage of CD4+ T cells, CD8+ T cells, IFN-γ, IL-4 using flowsitometry and IL-2 levels, IL-10 using the ELISA method. The results obtained that kefir do not affect the percentage of CD4+ T cells and CD8+ T cells. The higher the concentration of kefir given, the higher levels of secreted IFN- γ and IL-4, but a decrease in IL-2 levels. Significant enhancement occurred at levels of IL-10 culture PBMC given kefir with various concentrations (p <0.01), especially at concentrations of 1%. These results also show the important effects of kefir bioactive components on immune responses. The conclusion of this study is that kefir can improve the immune response, through stimulation of IL-10 secretion in vitro.

scholarly journals Early Response of CD8+ T Cells in COVID-19 Patients

2021 ◽  
Vol 11 (12) ◽  
pp. 1291
Author(s):  
Deni Ramljak ◽  
Martina Vukoja ◽  
Marina Curlin ◽  
Katarina Vukojevic ◽  
Maja Barbaric ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
T Cells ◽  
Mrna Expression ◽  
Cd8 T Cells ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Effector Memory ◽  
Healthy Controls ◽  
Ifn Γ

Healthy and controlled immune response in COVID-19 is crucial for mild forms of the disease. Although CD8+ T cells play important role in this response, there is still a lack of studies showing the gene expression profiles in those cells at the beginning of the disease as potential predictors of more severe forms after the first week. We investigated a proportion of different subpopulations of CD8+ T cells and their gene expression patterns for cytotoxic proteins (perforin-1 (PRF1), granulysin (GNLY), granzyme B (GZMB), granzyme A (GZMA), granzyme K (GZMK)), cytokine interferon-γ (IFN-γ), and apoptotic protein Fas ligand (FASL) in CD8+ T cells from peripheral blood in first weeks of SARS-CoV-2 infection. Sixteen COVID-19 patients and nine healthy controls were included. The absolute counts of total lymphocytes (p = 0.007), CD3+ (p = 0.05), and CD8+ T cells (p = 0.01) in COVID-19 patients were significantly decreased compared to healthy controls. In COVID-19 patients in CD8+ T cell compartment, we observed lower frequency effector memory 1 (EM1) (p = 0.06) and effector memory 4 (EM4) (p < 0.001) CD8+ T cells. Higher mRNA expression of PRF1 (p = 0.05) and lower mRNA expression of FASL (p = 0.05) at the fifth day of the disease were found in COVID-19 patients compared to healthy controls. mRNA expression of PRF1 (p < 0.001) and IFN-γ (p < 0.001) was significantly downregulated in the first week of disease in COVID-19 patients who progressed to moderate and severe forms after the first week, compared to patients with mild symptoms during the entire disease course. GZMK (p < 0.01) and FASL (p < 0.01) mRNA expression was downregulated in all COVID-19 patients compared to healthy controls. Our results can lead to a better understanding of the inappropriate immune response of CD8+ T cells in SARS-CoV2 with the faster progression of the disease.

scholarly journals CD8 T Cells Require Gamma Interferon To Clear Borna Disease Virus from the Brain and Prevent Immune System-Mediated Neuronal Damage

2005 ◽  
Vol 79 (21) ◽  
pp. 13509-13518 ◽  
Author(s):  
Jürgen Hausmann ◽  
Axel Pagenstecher ◽  
Karen Baur ◽  
Kirsten Richter ◽  
Hanns-Joachim Rziha ◽  
...  
Keyword(s):  
T Cells ◽  
Disease Virus ◽  
Cd8 T Cells ◽  
Gamma Interferon ◽  
Wild Type ◽  
Borna Disease Virus ◽  
Ifn Γ ◽  
The Brain ◽  
Deficient Mice ◽  
Borna Disease

ABSTRACT Borna disease virus (BDV) frequently causes meningoencephalitis and fatal neurological disease in young but not old mice of strain MRL. Disease does not result from the virus-induced destruction of infected neurons. Rather, it is mediated by H-2 k -restricted antiviral CD8 T cells that recognize a peptide derived from the BDV nucleoprotein N. Persistent BDV infection in mice is not spontaneously cleared. We report here that N-specific vaccination can protect wild-type MRL mice but not mutant MRL mice lacking gamma interferon (IFN-γ) from persistent infection with BDV. Furthermore, we observed a significant degree of resistance of old MRL mice to persistent BDV infection that depended on the presence of CD8 T cells. We found that virus initially infected hippocampal neurons around 2 weeks after intracerebral infection but was eventually cleared in most wild-type MRL mice. Unexpectedly, young as well as old IFN-γ-deficient MRL mice were completely susceptible to infection with BDV. Moreover, neurons in the CA1 region of the hippocampus were severely damaged in most diseased IFN-γ-deficient mice but not in wild-type mice. Furthermore, large numbers of eosinophils were present in the inflamed brains of IFN-γ-deficient mice but not in those of wild-type mice, presumably because of increased intracerebral synthesis of interleukin-13 and the chemokines CCL1 and CCL11, which can attract eosinophils. These results demonstrate that IFN-γ plays a central role in host resistance against infection of the central nervous system with BDV and in clearance of BDV from neurons. They further indicate that IFN-γ may function as a neuroprotective factor that can limit the loss of neurons in the course of antiviral immune responses in the brain.

scholarly journals Gamma Interferon Is Required for Chlamydia Clearance but Is Dispensable for T Cell Homing to the Genital Tract

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Jennifer D. Helble ◽  
Rodrigo J. Gonzalez ◽  
Ulrich H. von Andrian ◽  
Michael N. Starnbach
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Chlamydia Trachomatis ◽  
Genital Tract ◽  
Gamma Interferon ◽  
Cell Homing ◽  
Content Type ◽  
T Cell Homing ◽  
Ifn Γ

ABSTRACT While there is no effective vaccine against Chlamydia trachomatis infection, previous work has demonstrated the importance of C. trachomatis-specific CD4+ T cells (NR1 T cells) in pathogen clearance. Specifically, NR1 T cells have been shown to be protective in mice, and this protection depends on the host’s ability to sense the cytokine gamma interferon (IFN-γ). However, it is unclear what role NR1 production or sensing of IFN-γ plays in T cell homing to the genital tract or T cell-mediated protection against C. trachomatis. Using two-photon microscopy and flow cytometry, we found that naive wild-type (WT), IFN-γ−/−, and IFN-γR−/− NR1 T cells specifically home to sections in the genital tract that contain C. trachomatis. We also determined that protection against infection requires production of IFN-γ from either NR1 T cells or endogenous cells, further highlighting the importance of IFN-γ in clearing C. trachomatis infection. IMPORTANCE Chlamydia trachomatis is an important mucosal pathogen that is the leading cause of sexually transmitted bacterial infections in the United States. Despite this, there is no vaccine currently available. In order to develop such a vaccine, it is necessary to understand the components of the immune response that can lead to protection against this pathogen. It is well known that antigen-specific CD4+ T cells are critical for Chlamydia clearance, but the contexts in which they are protective or not protective are unknown. Here, we aimed to characterize the importance of gamma interferon production and sensing by T cells and the effects on the immune response to C. trachomatis. Our work here helps to define the contexts in which antigen-specific T cells can be protective, which is critical to our ability to design an effective and protective vaccine against C. trachomatis.

scholarly journals Interleukin 12 (IL-12) Is Crucial to the Development of Protective Immunity in Mice Intravenously Infected with Mycobacterium tuberculosis

1997 ◽  
Vol 186 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Andrea M. Cooper ◽  
Jeanne Magram ◽  
Jessica Ferrante ◽  
Ian M. Orme
Keyword(s):  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
T Cell Activation ◽  
Bacterial Growth ◽  
Cell Activation ◽  
Interferon Γ ◽  
Delayed Type Hypersensitivity ◽  
Interleukin 12 ◽  
Mycobacterium Tuberculosis Infection ◽  
Ifn Γ

Immunity to Mycobacterium tuberculosis infection is associated with the emergence of protective CD4 T cells that secrete cytokines, resulting in activation of macrophages and the recruitment of monocytes to initiate granuloma formation. The cytokine-mediating macrophage activation is interferon-γ (IFN-γ), which is largely dependent on interleukin-12 (IL-12) for its induction. To address the role of IL-12 in immunity to tuberculosis, IL-12 p40−/− mice were infected with M. tuberculosis and their capacity to control bacterial growth and other characteristics of their immune response were determined. The IL-12 p40−/− mice were unable to control bacterial growth and this appeared to be linked to the absence of both innate and acquired sources of IFN-γ. T cell activation as measured by delayed type hypersensitivity and lymphocyte accumulation at the site of infection were both markedly reduced in the IL-12 p40−/− mice. Therefore, IL-12 is essential to the generation of a protective immune response to M. tuberculosis, with its main functions being the induction of the expression of IFN-γ and the activation of antigen-specific lymphocytes capable of creating a protective granuloma.

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