Related Experiment Video
Updated: Aug 11, 2026

Murine Superficial Lymph Node Surgery
Published on: May 21, 2012
Sustained response initiation is required for T cell clonal expansion but not for effector or memory development in
Leo Lefrançois1, Amanda Marzo, Kristina Williams
1Department of Medicine, Division of Immunology, University of Connecticut Health Center, Farmington, CT 06030, USA. llefranc@neron.uchc.edu
Abstract:
The factors determining whether an immune response is productive are poorly understood. To understand the circumstances affecting the early stage of the immune response which determine whether memory is generated, the CD8 T cell response was mapped in detail following immunization with live or heat-killed bacteria. Our results demonstrate that even in response to a weak immunogen, functional memory cell development is linked to effector cell induction in lymphoid and nonlymphoid tissues. The main defect in the response to killed microorganisms is inefficient induction of clonal expansion. This failure is due to a contracted, but costimulation-dependent activation phase in the lymphoid tissues, resulting in rapid but abortive growth. Conversely, the response to live bacteria is characterized by protracted early T cell sequestration in lymphoid tissues. Thus, memory development requires effector induction, while optimal clonal expansion is regulated by the duration of response initiation.
More Related Videos
Related Concept Videos
Cell-mediated Immune Responses
Cells of the Adaptive Immune Response
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
T Cell Types and Functions
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
B Cell Activation and Differentiation
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...
Immunological Memory
What is Immunological Memory?
Immunological memory is an integral function of the immune system that allows it to recognize and react more rapidly and effectively to pathogens previously encountered. This feature is...

