Adaptive Immune System Components

“Adaptive Immune System Components” refers to the major cellular and molecular machinery responsible for specific, acquired immunity in vertebrates. The principal cellular components are **B cells** (B lymphocytes) and **T cells** (T lymphocytes), both of which arise from hematopoietic stem cells[1][7]. B cells mediate humoral immunity by producing antibodies (immunoglobulins) which neutralize pathogens and facilitate their clearance[4][6][7]. T cells comprise several subtypes: helper T cells (orchestrate immune responses via cytokine signaling), cytotoxic T cells (kill infected or malignant cells), and regulatory/memory T cell subsets[1][5][8]. These lymphocytes recognize antigens through highly variable, somatically rearranged receptors (B cell receptor [BCR] for B cells, T cell receptor [TCR] for T cells), enabling precise and diverse antigen recognition[3][7]. The adaptive immune system also possesses memory, providing faster and stronger responses to previously encountered antigens. However, “Adaptive Immune System Components” is not a single molecular entity or defined drug target—it encompasses a range of cells, receptors, and proteins such as *immunoglobulin classes* (IgG, IgA, IgM, etc.), T cell coreceptors (CD4, CD8), and MHC molecules[4][6]. Each of these could serve as an individual target, but the overall system is too broad and complex to be classified as a single molecular target for drug development[7][1].

Other names

Adaptive immunityAcquired immune systemHumoral and cell-mediated immune responseB lymphocyte and T lymphocyte immune response