scholarly journals Perforin-Deficient CD8+ T Cells Mediate Fatal Lymphocytic Choriomeningitis despite Impaired Cytokine Production

2006 ◽  
Vol 80 (3) ◽  
pp. 1222-1230 ◽  
Author(s):  
Pernille Storm ◽  
Christina Bartholdy ◽  
Maria Rathman Sørensen ◽  
Jan Pravsgaard Christensen ◽  
Allan Randrup Thomsen
Keyword(s):  
T Cells ◽  
Inflammatory Cells ◽  
Lymphocytic Choriomeningitis ◽  
Effector T Cells ◽  
Fatal Disease ◽  
Effector Cells ◽  
Proinflammatory Mediators ◽  
The Central Nervous System ◽  
Deficient Mice

ABSTRACT Intracerebral (i.c.) infection with lymphocytic choriomeningitis virus (LCMV) is one of the most studied models for virus-induced immunopathology, and based on results from perforin-deficient mice, it is currently assumed that fatal disease directly reflects perforin-mediated cell lysis. However, recent studies have revealed additional functional defects within the effector T cells of LCMV-infected perforin-deficient mice, raising the possibility that perforin may not be directly involved in mediating lethal disease. For this reason, we decided to reevaluate the role of perforin in determining the outcome of i.c. infection with LCMV. We confirmed that the expansion of virus-specific CD8+ T cells is unimpaired in perforin-deficient mice. However, despite the fact that the virus-specific CD8+ effector T cells in perforin-deficient mice are broadly impaired in their effector function, these mice invariably succumb to i.c. infection with LCMV strain Armstrong, although a few days later than matched wild-type mice. Upon further investigation, we found that this delay correlates with the delayed recruitment of inflammatory cells to the central nervous system (CNS). However, CD8+ effector T cells were not kept from the CNS by sequestering in infected extraneural organ sites such as liver or lungs. Thus, the observed dysfunctionality regarding the production of proinflammatory mediators probably results in the delayed recruitment of effector cells to the CNS, and this appears to be the main explanation for the delayed onset of fatal disease in perforin-deficient mice. However, once accumulated in the CNS, virus-specific CD8+ T cells can induce fatal CNS pathology despite the absence of perforin-mediated lysis and reduced capacity to produce several key cytokines.

scholarly journals Role of Macrophage Inflammatory Protein-1α in T-Cell-Mediated Immunity to Viral Infection

2003 ◽  
Vol 77 (22) ◽  
pp. 12378-12384 ◽  
Author(s):  
Andreas N. Madsen ◽  
Anneline Nansen ◽  
Jan P. Christensen ◽  
Allan R. Thomsen
Keyword(s):  
T Cell ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Effector T Cells ◽  
Cell Mediated Immunity ◽  
Inflammatory Protein ◽  
Specific Effector ◽  
Macrophage Inflammatory Protein ◽  
Deficient Mice

ABSTRACT The immune response to lymphocytic choriomeningitis virus in mice lacking macrophage inflammatory protein-1α (MIP-1α) was evaluated. Generation of virus-specific effector T cells is unimpaired in MIP-1α-deficient mice. Furthermore, MIP-1α is not required for T-cell-mediated virus control or virus-induced T-cell-dependent inflammation. Thus, MIP-1α is not mandatory for T-cell-mediated antiviral immunity.

scholarly journals CD4+ T-Cell Responses Are Required for Clearance of West Nile Virus from the Central Nervous System

2006 ◽  
Vol 80 (24) ◽  
pp. 12060-12069 ◽  
Author(s):  
Elizabeth M. Sitati ◽  
Michael S. Diamond
Keyword(s):  
Central Nervous System ◽  
T Cells ◽  
Nervous System ◽  
West Nile Virus ◽  
T Cell ◽  
Wild Type ◽  
Cell Responses ◽  
The Central Nervous System ◽  
Deficient Mice

ABSTRACT Although studies have established that innate and adaptive immune responses are important in controlling West Nile virus (WNV) infection, the function of CD4+ T lymphocytes in modulating viral pathogenesis is less well characterized. Using a mouse model, we examined the role of CD4+ T cells in coordinating protection against WNV infection. A genetic or acquired deficiency of CD4+ T cells resulted in a protracted WNV infection in the central nervous system (CNS) that culminated in uniform lethality by 50 days after infection. Mice surviving past day 10 had high-level persistent WNV infection in the CNS compared to wild-type mice, even 45 days following infection. The absence of CD4+ T-cell help did not affect the kinetics of WNV infection in the spleen and serum, suggesting a role for CD4-independent clearance mechanisms in peripheral tissues. WNV-specific immunoglobulin M (IgM) levels were similar to those of wild-type mice in CD4-deficient mice early during infection but dropped ∼20-fold at day 15 postinfection, whereas IgG levels in CD4-deficient mice were ∼100- to 1,000-fold lower than in wild-type mice throughout the course of infection. WNV-specific CD8+ T-cell activation and trafficking to the CNS were unaffected by the absence of CD4+ T cells at day 9 postinfection but were markedly compromised at day 15. Our experiments suggest that the dominant protective role of CD4+ T cells during primary WNV infection is to provide help for antibody responses and sustain WNV-specific CD8+ T-cell responses in the CNS that enable viral clearance.

scholarly journals Interleukin 15 Is Required for Proliferative Renewal of Virus-specific Memory CD8 T Cells

2002 ◽  
Vol 195 (12) ◽  
pp. 1541-1548 ◽  
Author(s):  
Todd C. Becker ◽  
E. John Wherry ◽  
David Boone ◽  
Kaja Murali-Krishna ◽  
Rustom Antia ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Lymphocytic Choriomeningitis ◽  
Memory Cd8 T Cells ◽  
Cell Responses ◽  
Specific Memory ◽  
Interleukin 15 ◽  
Immunological Protection ◽  
Deficient Mice

The generation and efficient maintenance of antigen-specific memory T cells is essential for long-lasting immunological protection. In this study, we examined the role of interleukin (IL)-15 in the generation and maintenance of virus-specific memory CD8 T cells using mice deficient in either IL-15 or the IL-15 receptor α chain. Both cytokine- and receptor-deficient mice made potent primary CD8 T cell responses to infection with lymphocytic choriomeningitis virus (LCMV), effectively cleared the virus and generated a pool of antigen-specific memory CD8 T cells that were phenotypically and functionally similar to memory CD8 T cells present in IL-15+/+ mice. However, longitudinal analysis revealed a slow attrition of virus-specific memory CD8 T cells in the absence of IL-15 signals.This loss of CD8 T cells was due to a severe defect in the proliferative renewal of antigen-specific memory CD8 T cells in IL-15−/− mice. Taken together, these results show that IL-15 is not essential for the generation of memory CD8 T cells, but is required for homeostatic proliferation to maintain populations of memory cells over long periods of time.

scholarly journals The Role of CD8+ T Cells and Major Histocompatibility Complex Class I Expression in the Central Nervous System of Mice Infected with Neurovirulent Sindbis Virus

2000 ◽  
Vol 74 (13) ◽  
pp. 6117-6125 ◽  
Author(s):  
Takashi Kimura ◽  
Diane E. Griffin
Keyword(s):  
T Cells ◽  
Mhc Class I ◽  
Sindbis Virus ◽  
Inflammatory Cells ◽  
Class I ◽  
Ependymal Cells ◽  
Histocompatibility Complex ◽  
The Central Nervous System ◽  
Mhc Class I Molecules

ABSTRACT Little is known about the role of CD8+ T cells infiltrating the neural parenchyma during encephalitis induced by neurovirulent Sindbis virus (NSV). NSV preferentially infects neurons in the mouse brain and spinal cord; however, it is generally accepted that neurons can express few if any major histocompatibility complex (MHC) class I molecules. We evaluated the possible roles and interactions of CD8+ T cells during NSV encephalitis and demonstrated that MHC class I antigen (H2K/D) was expressed on endothelial cells, inflammatory cells, and ependymal cells after intracerebral inoculation of NSV. No immunoreactivity was observed in neurons. On the other hand, in situ hybridization with probes for MHC class I heavy chain, β2 microglobulin, and TAP1 and TAP2 mRNAs revealed increased expression in a majority of neurons, as well as in inflammatory cells, endothelial cells, and ependymal cells in the central nervous system of infected mice. NSV-infected neurons may fail to express MHC class I molecules due to a posttranscriptional block or may express only nonclassical MHC class I genes. To better understand the role CD8+ T cells play during fatal encephalitis induced by NSV, mice lacking functional CD8+ T cells were studied. The presence or absence of CD8 did not alter outcome, but absence of β2 microglobulin improved survival. Interestingly, the intracellular levels of viral RNA decreased more rapidly in immunocompetent mice than in mice without functional CD8+ T cells. These observations suggest that CD8+ T cells may act indirectly, possibly via cytokines, to contribute to the clearance of viral RNA in neurons.

scholarly journals Potential Role of Trace Elements (Al, Cu, Zn, and Se) in Multiple Sclerosis Physiopathology

2020 ◽  
Vol 27 (4) ◽  
pp. 163-177
Author(s):  
Mohammad Sadegh Hesamian ◽  
Nahid Eskandari
Keyword(s):  
Multiple Sclerosis ◽  
T Cells ◽  
Trace Elements ◽  
Plasma Cells ◽  
Peripheral Tolerance ◽  
The Central Nervous System ◽  
Living Organisms ◽  
Tolerance Breakdown ◽  
Peripheral Immune Cells

Multiple sclerosis (MS) is an unpredictable disease of the central nervous system. The cause of MS is not known completely, and pathology is specified by involved demyelinated areas in the white and gray matter of the brain and spinal cord. Inflammation and peripheral tolerance breakdown due to Treg cell defects and/or effector cell resistance are present at all stages of the disease. Several invading peripheral immune cells are included in the process of the disease such as macrophages, CD8+ T cells, CD4+ T cells, B cells, and plasma cells. Trace elements are known as elements found in soil, plants, and living organisms in small quantities. Some of them (e.g., Al, Cu, Zn, Mn, and Se) are essential for the body’s functions like catalysts in enzyme systems, energy metabolism, etc. Al toxicity and Cu, Zn, and Se toxicity and deficiency can affect the immune system and following neuron inflammation and degeneration. These processes may result in MS pathology. Of course, factors such as lifestyle, environment, and industrialization can affect levels of trace elements in the human body.

scholarly journals The Role of the Innate Immune System in Alzheimer’s Disease and Frontotemporal Lobar Degeneration: An Eye on Microglia

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Elisa Ridolfi ◽  
Cinzia Barone ◽  
Elio Scarpini ◽  
Daniela Galimberti
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Frontotemporal Lobar Degeneration ◽  
Environmental Changes ◽  
Current Evidence ◽  
Neuronal Function ◽  
Immune Effector ◽  
Effector Cells ◽  
The Central Nervous System

In the last few years, genetic and biomolecular mechanisms at the basis of Alzheimer’s disease (AD) and frontotemporal lobar degeneration (FTLD) have been unraveled. A key role is played by microglia, which represent the immune effector cells in the central nervous system (CNS). They are extremely sensitive to the environmental changes in the brain and are activated in response to several pathologic events within the CNS, including altered neuronal function, infection, injury, and inflammation. While short-term microglial activity has generally a neuroprotective role, chronic activation has been implicated in the pathogenesis of neurodegenerative disorders, including AD and FTLD. In this framework, the purpose of this review is to give an overview of clinical features, genetics, and novel discoveries on biomolecular pathogenic mechanisms at the basis of these two neurodegenerative diseases and to outline current evidence regarding the role played by activated microglia in their pathogenesis.

scholarly journals Regional CNS responses to IFN-γ determine lesion localization patterns during EAE pathogenesis

2008 ◽  
Vol 205 (11) ◽  
pp. 2633-2642 ◽  
Author(s):  
Jason R. Lees ◽  
Paul T. Golumbek ◽  
Julia Sim ◽  
Denise Dorsey ◽  
John H. Russell
Keyword(s):  
Spinal Cord ◽  
T Cells ◽  
Brain Stem ◽  
Clinical Outcomes ◽  
Clinical Symptoms ◽  
Inflammatory Cells ◽  
Th1 Cells ◽  
Autoimmune Encephalomyelitis ◽  
The Central Nervous System ◽  
Ifn Γ

The localization of inflammatory foci within the cerebellum is correlated to severe clinical outcomes in multiple sclerosis (MS). Previous studies of experimental autoimmune encephalomyelitis (EAE), a model of MS, revealed distinct clinical outcomes correlated with the capacity of the animal to produce IFN-γ. Outcomes were linked to localization of inflammatory cells in either the spinal cord (wild type [WT]) or the cerebellum and brain stem (IFN-γ deficient). We demonstrate, using an adoptive transfer system, that the ability of the central nervous system (CNS) to sense pathogenic T cell–produced IFN-γ during EAE initiation determines the sites of CNS pathogenesis. Transfer of WT Th1 cells into IFN-γ receptor–deficient mice results in pathogenic invasion of the brain stem and cerebellum with attendant clinical symptoms, which are identical to the disease observed after transfer of IFN-γ–deficient T cells to WT hosts. Inflammation of the spinal cord associated with classical EAE is abrogated in both IFN-γ–deficient systems. Cotransfer of CNS antigen-specific WT Th1 cells with IFN-γ–deficient T cells is sufficient to restore spinal cord invasion and block cerebellar and brain stem invasion. These data demonstrate that interaction between IFN-γ and host CNS cells during the initiation of EAE can selectively promote or suppress neuroinflammation and pathogenesis.

Immunohistochemical Study of Presence of T Cells, B Cells, and Macrophages in Periradicular Lesions of Primary Teeth

2008 ◽  
Vol 32 (4) ◽  
pp. 287-293 ◽  
Author(s):  
Michele Bolan ◽  
Daniele de Almeida Lima ◽  
Cláudia Pinto Figueiredo ◽  
Gabriella Di Giunta ◽  
Maria José de Carvalho Rocha
Keyword(s):  
T Cells ◽  
Immune System ◽  
B Cells ◽  
Primary Teeth ◽  
Microscopic Analysis ◽  
Inflammatory Cells ◽  
Periapical Lesions ◽  
Inflammatory Processes ◽  
Local Inflammatory Reaction

BACKGROUND: The periapical lesion is the result of a local inflammatory reaction caused by bacteria and its products present on the root canal. The interaction between inflammatory cells and bacteria elicit both specific and non-specific immune responses. OBJETIVE: Due to the lack of studies evaluating the role of the immune system in periapical lesions of primary teeth and considering the potentially systemic effects that these infections can cause in children, especially because of the immaturity of their immune system, we sought to evaluate the presence of T cells, B cells and macrophages on periradicular lesions in primary teeth. STUDY DESIGN: 14 periradicular lesions were analyzed. The immunohistochemistry technique was performed using CD45RO, CD20, CD68 monoclonal antibodies aiming to identify T cells, B cells and macrophages, respectively. Cells were quantified by microscopic analysis of histological sections. RESULTS: Mean percentage of positive cells CD45RO was 11.76; CD20 was 5.25; CD68 was 10.92. Our results showed that T and B cells and macrophages comprise the majority of the inflammatory infiltrate. CONCLUSION: We concluded that both humoral and cell mediated immune reactions take place in periradicular lesions of primary teeth. The immune system plays an important role on the periradicular inflammatory processes in primary teeth.

scholarly journals m6A demethylase ALKBH5 controls CD4+ T cell pathogenicity and promotes autoimmunity

2021 ◽  
Vol 7 (25) ◽  
pp. eabg0470
Author(s):  
Jing Zhou ◽  
Xingli Zhang ◽  
Jiajia Hu ◽  
Rihao Qu ◽  
Zhibin Yu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Messenger Rna ◽  
Interferon Γ ◽  
Autoimmune Encephalomyelitis ◽  
Cell Responses ◽  
Chemokine Ligand ◽  
The Central Nervous System ◽  
Chemokine Ligand 2

N6-methyladenosine (m6A) modification is dynamically regulated by “writer” and “eraser” enzymes. m6A “writers” have been shown to ensure the homeostasis of CD4+ T cells, but the “erasers” functioning in T cells is poorly understood. Here, we reported that m6A eraser AlkB homolog 5 (ALKBH5), but not FTO, maintains the ability of naïve CD4+ T cells to induce adoptive transfer colitis. In addition, T cell–specific ablation of ALKBH5 confers protection against experimental autoimmune encephalomyelitis. During the induced neuroinflammation, ALKBH5 deficiency increased m6A modification on interferon-γ and C-X-C motif chemokine ligand 2 messenger RNA (mRNA), thus decreasing their mRNA stability and protein expression in CD4+ T cells. These modifications resulted in attenuated CD4+ T cell responses and diminished recruitment of neutrophils into the central nervous system. Our findings reveal an unexpected specific role of ALKBH5 as an m6A eraser in controlling the pathogenicity of CD4+ T cells during autoimmunity.

scholarly journals PD-1 expression on NK cells can be related to cytokine stimulation and tissue residency

2021 ◽  
Author(s):  
Arnika K Wagner ◽  
Nadir Kadri ◽  
Chris Tibbitt ◽  
Koen van de Ven ◽  
Sunitha Bagawath-Singh ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Nk Cells ◽  
Mhc Class I ◽  
Sequencing Analysis ◽  
Single Cell Rna Sequencing ◽  
Cytokine Stimulation ◽  
Deficient Mice

ABSTRACTAlthough PD-1 was shown to be a hallmark of T cells exhaustion, controversial studies have been reported on the role of PD-1 on NK cells. Here, we found by flow cytometry and single cell RNA sequencing analysis that PD-1 can be expressed on MHC class I-deficient tumor-infiltrating NK cells in vivo. We also demonstrate distinct alterations in the phenotype of PD-1-deficient NK cells which in part could be attributed to a decrease in tumor-infiltrating NK cells in PD-1-deficient mice. NK cells from PD-1-deficient mice exhibited a more mature phenotype which might reduce their capacity to migrate and kill in vivo. Finally, our results demonstrate that PD-L1 molecules in membranes of PD-1-deficient NK cells migrate faster than in NK cells from wildtype mice, suggesting that PD-1 and PD-L1 form cis interactions with each other on NK cells.

Sign in / Sign up

Export Citation Format

Share Document