Related Experiment Video

Updated: Aug 18, 2026

Generation of Human Alloantigen-specific T Cells from Peripheral Blood
09:47

Generation of Human Alloantigen-specific T Cells from Peripheral Blood

Published on: November 21, 2014

Microparticles shed from different antigen-presenting cells display an individual pattern of surface molecules and a

W Kolowos1, U S Gaipl, A Sheriff

  • 1Department of Internal Medicine III, Institute for Clinical Immunology and Rheumatology, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany.

Scandinavian Journal of Immunology
|March 25, 2005
PubMed

Insights

Microparticles (MPs) from human antigen-presenting cells (APCs) vary in size and surface proteins. MPs from dendritic cells (DCs) and macrophages show distinct properties and immune-stimulating effects, influencing T-cell responses.

Area of Science:

  • Immunology
  • Cell Biology
  • Biotechnology

Background:

  • Cells release microparticles (MPs), which are small vesicles derived from cell surfaces.
  • Antigen-presenting cells (APCs), including dendritic cells (DCs) and macrophages, are crucial for initiating immune responses.
  • The characteristics and functions of MPs derived from various cell types, especially APCs, are not fully understood.

Purpose of the Study:

  • To analyze the size, surface protein composition, and immunomodulatory functions of MPs derived from human APCs.
  • To compare MPs from dendritic cells (DCs) with those from monocytes and macrophages.
  • To investigate the impact of cellular treatments (UV-B, lipopolysaccharide) and apoptosis on MP properties.

Main Methods:

  • Isolation and characterization of MPs from cultured human APCs and cell lines.
  • Particle sizing using dynamic light scattering.
  • Surface protein analysis using flow cytometry.
  • Functional assays to assess T-cell stimulation and immunomodulatory capacity.

Main Results:

  • MPs from viable APCs ranged from 80-300 nm, while MPs from irradiated cells were larger (400-1200 nm).
  • MPs exhibited altered surface protein composition compared to their parent cells, with distinct profiles for DC-derived MPs versus monocyte/macrophage-derived MPs.
  • MPs from DCs and macrophages demonstrated T-cell stimulatory capacity, influenced by cellular treatments and apoptotic status.
  • Apoptotic macrophage MPs could suppress vital macrophage activity, whereas apoptotic DC MPs remained stimulatory.

Conclusions:

  • This study provides the first comprehensive comparison of MPs released from dendritic cells (DCs) and other antigen-presenting cells (APCs).
  • MP characteristics (size, surface proteins) and functions (immunostimulation) are significantly influenced by the cell of origin, cellular treatments, and apoptotic state.
  • DC-derived MPs possess unique properties and potent immunostimulatory effects, highlighting their potential role in immune regulation and therapeutic applications.

More Related Videos

Identification of Rare Antigen-Specific T Cells from Mouse Lungs with Peptide:Major Histocompatibility Complex Tetramers09:15

Identification of Rare Antigen-Specific T Cells from Mouse Lungs with Peptide:Major Histocompatibility Complex Tetramers

Published on: July 19, 2024

Artificial Antigen Presenting Cell (aAPC) Mediated Activation and Expansion of Natural Killer T Cells13:18

Artificial Antigen Presenting Cell (aAPC) Mediated Activation and Expansion of Natural Killer T Cells

Published on: December 29, 2012

Related Concept Videos

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...
Antigens Involved in Adaptive Immunity01:26

Antigens Involved in Adaptive Immunity

An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Antigen Presenting Cells01:22

Antigen Presenting Cells

The immune system is a complex network of cells and molecules that protects the body from foreign invaders. T cells, a type of white blood cell, play a crucial role in this process. They recognize and attack foreign substances, such as pathogens, that enter the body.
T cells require the help of antigen-presenting cells (APCs), which process foreign antigens into smaller fragments that can be recognized by T cells. These APCs are highly specialized cells that efficiently internalize antigens...
Diversity of Antigen Receptors01:28

Diversity of Antigen Receptors

Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Antigen Processing Pathways01:31

Antigen Processing Pathways

MHC molecules are key players in the immune response, enabling T cells to recognize and respond to specific antigens. They are present on the surface of all nucleated cells in the body and are instrumental in presenting antigens to T cells and activating them. T cells recognize the MHC-antigen complex and initiate an immune response. MHC class I and MHC class II are two main types of MHC molecules, each associated with a distinct antigen processing pathway.
MHC Class I: Presenting Endogenous...
B Cell Activation and Differentiation01:24

B Cell Activation and Differentiation

The adaptive immune response, a sophisticated defense mechanism, relies on the activation and differentiation of B lymphocytes, or B cells. These processes enable our bodies to mount a tailored response against specific pathogens such as bacteria, free virus particles, toxins, and parasites.
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...