Adaptive Immunity

Antigen Processing and Immune Response

• Dendritic cells and macrophages are the primary cells that process antigens in the immune system.

T Cell Regulation and Immunity

• The term for the subset of T cells that regulate the immune response is T regulatory cells.
• Passive immunity involves the transfer of preformed antibodies or T lymphocytes from a donor to the recipient.

Antigens and Immune Response

• Haptens are small-molecular-weight antigens that are not themselves immunogenic.
• The molecule responsible for binding antigen in the B cell receptor complex is immunoglobulin.
• MHC (Major Histocompatibility Complex) molecules present endogenous protein antigens in the immune system.

Genetics and Immunity

• The MHC genes are located on human chromosome 6.
• The class of antibody in the immune system is determined by the heavy chain constant region.
• The cluster of genes found on human chromosome 6, also called HLA antigens, is referred to as the Human Leukocyte Antigen complex.

Adaptive Immunity

• Adaptive immunity is produced after natural exposure to an antigen or after immunization.
• The main characteristic that distinguishes adaptive immunity from innate immunity is specificity.
• T cells, specifically T lymphocytes, are responsible for cell-mediated immunity.
• The function of B lymphocytes in the immune response is to produce antibodies.
• The process of B and T cells having an extensive diversity of antigen receptors capable of recognizing different antigens is called clonal selection.
• Humoral immunity is mediated by circulating antibodies.
• The main function of T lymphocytes in the immune response is to recognize and eliminate infected cells or produce chemical signals that activate other immune responses.

Immune Response Characteristics

• The adaptive immune response is much longer lived compared to the innate inflammatory response due to the generation of immunological memory.
• The clonal selection of B and T cells is initiated by antigen recognition.
• The immune response that consists of lymphocytes and serum proteins called antibodies is called humoral immunity.
• The main function of cells of the innate system in the adaptive immune response is to provide an early defense against infection and activate the adaptive immune response.