Related Experiment Video

Updated: Aug 22, 2026

In Vitro and In Vivo Assessment of T, B and Myeloid Cells Suppressive Activity and Humoral Responses from Transplant Recipients
18:48

In Vitro and In Vivo Assessment of T, B and Myeloid Cells Suppressive Activity and Humoral Responses from Transplant Recipients

Published on: August 12, 2017

Heterologous immunity and homeostatic proliferation as barriers to tolerance

Devon K Taylor1, David Neujahr, Laurence A Turka

  • 1University of Pennsylvania, 700 Clinical Research Building, 415 Curie Boulevard, Philadelphia 19104-6144, USA.

Current Opinion in Immunology
|September 3, 2004
PubMed

The different threshold of activation for memory T cells compared to that of naïve T cells makes them resistant to immunomodulation, thus representing a barrier to tolerance. Recently it has been demonstrated that homeostatic proliferation and heterologous immunity represent two naturally occurring and distinct processes that can generate memory T cells. Homeostatic proliferation refers to the process by which, in a lymphodeficient host, normal T cells 'spontaneously' proliferate in response to self-MHC-peptide complexes. Heterologous immunity refers to a process in which a response to one or more infectious agents generates effector/memory T cells with cross-reactive specificities. Recent new studies have defined the importance of these processes in transplantation models and implicated strategies to induce transplantation tolerance.

More Related Videos

Interrogating Individual Autoreactive Germinal Centers by Photoactivation in a Mixed Chimeric Model of Autoimmunity11:12

Interrogating Individual Autoreactive Germinal Centers by Photoactivation in a Mixed Chimeric Model of Autoimmunity

Published on: April 11, 2019

Generation of Human Alloantigen-specific T Cells from Peripheral Blood09:47

Generation of Human Alloantigen-specific T Cells from Peripheral Blood

Published on: November 21, 2014

Related Concept Videos

Special Features of Adaptive Immunity01:20

Special Features of Adaptive Immunity

The adaptive immune system, a crucial component of the overall immune response, offers a highly specialized defense against pathogens. It involves specific cell types and features, enabling it to combat infections effectively and efficiently.
The primary cell types involved in adaptive immunity are T cells and B cells. Each type has a unique role in defending the body against pathogens. T cells are responsible for cell-mediated immunity. They identify and eliminate infected cells directly,...
Cell-mediated Immune Responses01:40

Cell-mediated Immune Responses

Overview
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.
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...
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...