Acquired Immunity 1

This set of vocabulary flashcards covers the essential components of acquired immunity, including antibody structure, classes of immunoglobulins, and the mechanisms of antigen presentation.

Two components of acquired immunity

Humoral - production of antibodies (missiles)

Cell-mediated - activated cells that kill organisms (soldiers). B and T lymphocytes

Specificity

The principle that only a specific group of lymphocytes, known as a clone, recognize an antigen from a particular microbe.

Antigen

A general term for a material that induces an immune response or reacts with antibodies.

Immunogen

An antigen that induces an immune response. All immunogens are antigens, but not all antigens are immunogens

Hapten

A low-molecular weight material that is non-immunogenic on its own but becomes immunogenic if conjugated to a carrier molecule.

Plasma cells

Activated B-lymphocytes responsible for producing antibodies.

Antibody Variable region

Located at the N-terminus of the antibody arms, these sites are responsible for antigen binding.

IgG

Monomeric, represents 85% of antibodies. Produced during the secondary response.

IgM

Pentameric, 10% of antibodies. Produced during the primary response.

IgA

5% of antibodies. Exists as a monomer / dimer (Dimeric IgA is secreted in saliva)

IgD

Monomeric. Present on the surface of B-lymphocytes.

IgE

Monomeric; involved in acute inflammation, allergic reactions, parasitic infections.

What do antibodies do once they bind?

Neutralization

Agglutination

Opsonization

Complement activation (classical pathway)

Acute inflammation

Antibody-dependent cell-mediated cytotoxicity (ADCC)

Neutralization

An antibody function that involves the deactivation of a toxin, prevention of viral attachment, or blocking a bacterial surface receptor.

Agglutination

The process where antibodies cause the aggregation of microbes.

Opsonization

The coating of a microbe with molecules like antibodies, complement proteins, or acute phase proteins to make it easier for cells to engulf.

Antibody-mediated acute inflammation

Although acute inflammation is innate immunity, presence of antibodies makes this response stronger

Antibody-dependent cell-mediated cytotoxicity (ADCC)

The killing of large parasites or tumor cells by NK cells, macrophages, and eosinophils.

Cytokines

Soluble proteins that serve as intercellular communication factors to regulate differentiation, proliferation, and activation / inhibition of immune cells.

Major Histocompatibility Complex (MHC)

Process and present antigens to activate T-lymphocytes. MHC plays an important role in transplant rejection.

MHC I

MHC molecules present on almost all cell types that link to viral or self-antigens to activate T-cytotoxic cells.

MHC II

Present on antigen-presenting cells (APCs) like macrophages, dendritic cells, and B-lymphocytes that activate T-helper cells.