Related Experiment Video

Updated: May 25, 2026

A DNA/Ki67-Based Flow Cytometry Assay for Cell Cycle Analysis of Antigen-Specific CD8 T Cells in Vaccinated Mice
09:17

A DNA/Ki67-Based Flow Cytometry Assay for Cell Cycle Analysis of Antigen-Specific CD8 T Cells in Vaccinated Mice

Published on: January 5, 2021

Defective CD8 T cell responses in aged mice are due to quantitative and qualitative changes in virus-specific

Vilma Decman1, Brian J Laidlaw, Travis A Doering

  • 1Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.

Journal of Immunology (Baltimore, Md. : 1950)
|January 17, 2012
PubMed

Insights

Aging impairs CD8 T cell immunity due to fewer virus-specific precursors and lower quality T cells. Aged CD8 T cells exhibit exhaustion markers, reducing immune response effectiveness against infections.

Area of Science:

  • Immunology
  • Aging Research
  • Infectious Disease

Background:

  • Aging is linked to diminished CD8 T cell responses during viral infections.
  • The causes of these suboptimal responses remain unclear, with possibilities including environmental factors or intrinsic changes in T cells.

Purpose of the Study:

  • To investigate age-related quantitative and qualitative changes in antigen-specific CD8 T cells.
  • To determine the impact of these changes on immune response to viral infections.

Main Methods:

  • Analysis of CD8 T cell populations in aged and young mice, focusing on CD44 expression and inhibitory receptors (PD1, LAG3, 2B4, CD160).
  • Transcriptional profiling of aged CD8 T cells.
  • Assessment of virus-specific precursor frequencies.
  • T cell receptor (TCR) transgenic studies to compare CD44(Hi) and CD44(Lo) CD8 T cell function.

Main Results:

  • Aged mice showed a majority of CD8 T cells with high CD44 expression and increased inhibitory receptors, resembling exhausted T cells.
  • Virus-specific CD8 T cell precursors decreased significantly (up to 10-fold) in aged mice, with many exhibiting high CD44 and PD1 expression.
  • CD44(Hi) CD8 T cells from aged mice were qualitatively inferior to CD44(Lo) cells, irrespective of donor age.

Conclusions:

  • Aging leads to a reduced number of virus-specific CD8 T cell precursors.
  • Qualitative defects in CD8 T cells, characterized by increased exhaustion markers and impaired function, contribute to decreased immunity in aged individuals.
  • Both decreased precursor frequency and altered T cell quality are directly implicated in impaired immune responses during aging.

More Related Videos

Accessing Early Differentiation of Virus-Specific Follicular Helper CD4+ T Cell in Acute LCMV-Infected Mice05:03

Accessing Early Differentiation of Virus-Specific Follicular Helper CD4+ T Cell in Acute LCMV-Infected Mice

Published on: April 26, 2024

Tailoring In Vivo Cytotoxicity Assays to Study Immunodominance in Tumor-specific CD8+ T Cell Responses10:13

Tailoring In Vivo Cytotoxicity Assays to Study Immunodominance in Tumor-specific CD8+ T Cell Responses

Published on: May 6, 2019

Related Concept Videos

Immune Response Against Viral Pathogens01:29

Immune Response Against Viral Pathogens

The immune system's response to viral infections is a complex and coordinated process involving natural killer (NK) cells, T cell-mediated responses, and antibody-mediated responses.
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
Cytotoxic T Cells-mediated Immune Response01:27

Cytotoxic T Cells-mediated Immune Response

Cytotoxic T cells are a vital component of the immune system. They have the remarkable ability to identify and target antigens on infected or abnormal cells. These antigens often originate from intracellular pathogens such as viruses or abnormal proteins cancer cells produce.
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...