Acquired Immune System / Adaptive Immune System

Acquired Immune System / Adaptive Immune System provides protection against infectious and malignant diseases. These effects are mediated by lymphocytes that sense and respond with targeted precision to perturbations induced by pathogens and tissue damage.
Chi et al. 2024a Cell 187(9): 2052

Under pathophysiological conditions, the adaptive immune system also contributes to autoimmune and inflammatory diseases.
Chi et al. 2024a Cell 187(9): 2052

The adaptive immune system is the collection of cells, factors, and effector mechanisms that recognize and respond to specific antigens coming from inside or outside the body.
Chi et al. 2024a Cell 187(9): 2052

Furthermore, the adaptive immune system is characterized by the emergence of immune memory, the remarkable ability of lymphocytes to respond rapidly and precisely to an antigen derived from a pathogen with which they have previously come into contact, thus mediating enhanced (or complete) protection against reinfection.
Chi et al. 2024a Cell 187(9): 2052

A hallmark of adaptive immune cell development is the expression of the Recombination-activating (rag) genes (recombination-activating gene (rag) 1 and rag 2 gene), encoding proteins that mediate rearrangement of the T cell and B cell receptor genes
Sun et al. 2023 Immunol Rev 314: DOI: 10.1111/imr.13197

The crucial step to activate adaptive immunity is APCs' priming naive, antigen-specific T cells. This step involves the presentation of an antigen and the stimulation of CD28 on T cells by a B7 molecule on the APCs. The Naive T cells / Th0 cells primed in this way begin to circulate. They proliferate and differentiate into T-effector cells.
Murphy et al. 2022 W.W. Norton & Company ISBN 978-0-393-68093-5

The generation of adaptive immunity often requires that nonself peptides are accompanied by adjuvants, which are either pathogen products or agents associated with cellular damage.
Patel & Minn 2018 Immunity 48: 417

The Acquired Immune System / Adaptive Immune System functions through the combined action of antigen-presenting cells (APCs) and T cells. Antigen presentation by MHC class I / HLA class I human to Cytotoxic T cell (CTL) is restricted to proteosome-generated peptides from intracellular pathogens. In contrast, the endocytic MHC class II / HLA class II human pathway presents only proteolytic peptides from extracellular pathogens to T helper cell
Cobb et al., 2004

Carbohydrates can stimulate immune responses independently of T cells; however, zwitterionic polysaccharides (ZPSs) from the capsules of some bacteria can activate T helper cell. This occurs via the MHCII endocytic pathway.
Cobb et al., 2004

Furthermore, these carbohydrates in APCs (antigen presenting cells) bind to MHC class II / HLA class II human to present them to T cells / T lymphocytes
Cobb et al., 2004

Local production of IL-1beta, IL-18 and/or IL-33 could induce the reguisite signals for activation of the adaptive immune system
Kaye et al., 1984

see also:
Bacterial Polysaccharide A (PSA)
Capsular Polysaccharides (CPSs)
Memory B cells
Memory T Cells
Non-Protein Antigens