In this article, we will discuss about the fascinating adaptive immune system. The It is a network of cells and organs that provide defense to the body against foreign particles. It provides a high specific immune response. We will discuss about the components and mechanism of this immune system. We will also provide references to learn and acknowledge the concept of adaptive immunity.
INTRODUCTION-ADAPTIVE IMMUNE SYSTEM:
An intricate network of molecules and cells known as the adaptive immune system is vital to the body’s defense against pathogens such bacteria, viruses, fungi, and parasites. It responds to invasive pathogens in a highly particular and customized manner, in contrast to the innate immune system, which offers quick, general defense mechanisms.
COMPONENTS OF ADAPTIVE IMMUNE SYSTEM:
The two main lymphocyte subtypes that make up the this system are B cells and T cells. T cells organize immune responses and launch direct attacks on infected cells, whereas B cells are in charge of making antibodies.
2. ANTIGEN PRESENTING CELLS:
These cells, which include B cells, dendritic cells, and macrophages, collect and deliver antigens to lymphocytes, triggering an immunological reaction. APCs are essential for stimulating T cells and encouraging B cells to produce antibodies.
3. MAJOR HISTOCOMPATIBILITY COMPLAXES:
T cells are presented with antigens by MHC molecules, sometimes referred to as human leukocyte antigens (HLAs). MHC class I molecules bind to CD8+ T cells, also known as cytotoxic T cells, whereas class II molecules bind to CD4+ T cells, also known as helper T cells.
MECHANISMS OF ADAPTIVE IMMUNE SYSTEM:
1. ANTIBODY-MEDIATED IMMUNITY:
In order to label pathogens for destruction by other immune cells or to trigger the complement system and eradicate the pathogen directly, B cells make antibodies that identify and bind to specific antigens on pathogens.
2. CELL MEDIATED IMMUNITY:
T lymphocytes are essential for cell-mediated immunity. Helper T cells aid in the coordination of immune responses by secreting cytokines and stimulating other immune cells, whereas cytotoxic T cells kill diseased or aberrant cells directly.
3. MEMORY RESPONSE:
The ability of the this system to develop immunological memory is one of its defining characteristics. The immune system produces certain B and T cells when it comes into contact with a disease for the first time. These cells can react quickly to future exposures, resulting in a quicker and more potent immune response.
SIGNIFICANCE OF ADAPTIVE IMMUNE SYSTEM IN HEALTH AND DISEASE:
Long-lasting defense against a variety of pathogens, such as bacteria, viruses, fungi, and parasites, is offered by the adaptive immune system. Vaccination confers immunity against infectious diseases by utilizing the concepts of adaptive immunity. Autoimmune illnesses arise when the defense system mistakenly targets healthy tissues and cells due to dysregulation of the adaptive immune system. Lupus, multiple sclerosis, and rheumatoid arthritis are a few examples. Through the use of immunological checkpoint inhibitors, chimeric antigen receptor (CAR) T cell therapy, and cancer vaccines, which use the defense system to target and eradicate cancer cells, the concepts of adaptive immunity have transformed the treatment of cancer.
The defense system known as the adaptive immune system is an amazing defense mechanism that protects the body from diseases in a particular and targeted manner while preserving tolerance to the host. Developing novel therapeutic techniques against infectious diseases, autoimmune disorders, and cancer requires an understanding of its components and mechanisms.
Janeway CA Jr, Travers P, Walport M, et al. Immunobiology: The Immune System in Health and Disease. 5th edition. New York: Garland Science; 2001. https://www.ncbi.nlm.nih.gov/books/NBK10757/
Abbas AK, Lichtman AH, Pillai S. Cellular and Molecular Immunology. 9th edition. Philadelphia, PA: Elsevier; 2017. https://evolve.elsevier.com/cs/product/9780323479783?role=student
Restifo NP, Dudley ME, Rosenberg SA. Adoptive immunotherapy for cancer: harnessing the T cell response. Nat Rev Immunol. 2012;12(4):269-281. doi:10.1038/nri3191 https://pubmed.ncbi.nlm.nih.gov/22437939/