- Immunity's 1st line of defense

Intact epithelium

- B Lymphocytes, T Lymphocytes, Antigen Presenting Cells (APCs)

Immune Triumvirate

- educated in the bone marrow

- synthesize antibodies (immunoglobulins) -->enhance phagocytic activity of macrophages

B lymphocytes

- educated in thymus

- secrete cytokines-->influence APCs

- act as helper or cytotoxic cell

T lymphocyte

- engulf enemy, degrade antigen

- present fragments to T lymphocytes

Macrophages

- fragments of antigen presented by APCs

- a part of the major histocompatability complex (MHC)

Epitopes

- only cells that possess specificity, discrimination and memory

B and T lymphocytes

- develop into immune competent cells in primary lymphoid tissue

- precursor to T & B lymphocytes, macrophages

- originate in bone marrow

Hematopoietic stem cells (HSCs)

- after B & T lymphocytes obtain cell membrane specific receptors for antigen they migrate here

Secondary lymphoid tissue

- antigens usually made of this

Protein

- this occurs when BcRs and TcRs recognize an antigen and are activated

- yields memory cells that are the concomitant end product

Clonal expansion

- must be foreign

- must be big (high molecular weight)

- must be clinically complex in composition

- must be degradable and presentable

Complete Antigen

- weak antigen

- surrounds some bacteria

Lipopolysaccharide Capsule (LPS)

- incomplete antigen

- by itself, it cannot be recognized by TcRs or BcRs and requires a carrier protein until after the 1st recognition

- antibodies are created to bind to it in the absence of a carrier protein

Haptens

- drug that binds to self proteins that allows them to be seen as foreign

- can be involved clinically in mediating allergic reactions

Penicillin

- antigenic without the participation of T lymphocytes

- has a structure that consists of repeating chemical units (flagellin protein)

- Antibody typically produced for these is in the IgM class

T-independent antigens

T-dependent antigens

- bind the MHC-TcR independent of APC processing

- nonspecifically activates many T cells -->

excess cytokine production

- lcan lead to toxic shock syndrome

Superantigens

- specific regions on antibodies that bind to specific epitopes

Paratopes

non-covalent

- type of immunity where the individual synthesizes their own antibodies either naturally by infection, or by artificial means (immunization/vaccination)

Active Immunity

- type of immunity that comes from the transfer of antibodies from one individual to another either naturally (transplacental) or artificially (anti-venom, anti-toxins, anti-Rh)

Passive Immunity

- type of immunity that comes from the transfer of lymphoid cells (not antibodies) from an actively immunized donor (T lymphocytes)

Adoptive Immunity

- the non-specific kind of immunity that is the native or non-adaptive host response to invasion

Innate Immunity

- type of immunity that involves the immune triumvirate

- adaptive and specific

- discriminates between "self" and "non-self"

- has memory (anamnestic response)

Acquired Immunity

- this type of immunity relates primarily to B Lymphocytes

- synthesis and secretion of antibodies or immunoglobulins found in serum

Humoral Immunity

- cell surface immunoglobulin that is composed of two heavy and two light chains (variable and constant)

BcR (B Lymphocyte Cell Receptor)

- Only types of antibodies of the BcR that are mature AND naive

IgM & IgD

- type of immunity that involves T Lymphocytes (TcRs), epitope presentation (with MHCs), and creation of memory cells

Cell-Mediated (T-lymphocyte mediated) Immunity

- help 'turn on' B & T lymphocytes and other cell types

T helper cells

- primary cells involved in cell-mediated immunity

- responsible for killing virus-infected host cells

T cytotoxic cells

- comes from an inappropriate reaction to 'self' antigens

- example: rheumatoid arthritis

Autoimmune disease

- ineffective immune responses that include defects in T and/or B lymphocytes

- defects also can occur in phagocytes (PMNs and macrophages)

- deficiencies in complement components

- example: AIDS

Immunodeficiency

- overactive immune responses resulting from inappropriate response to antigens encountered a second or subsequent time

- example: allergies, Rh incompatibility, Rheumatoid arthritis, contact dermatitis

Hypersensitivity (dysfunctional immune system)

- provides adaptive immunity for blood infections

Spleen

- created after the 1st antigen interaction with T and B lymphocyte receptors

- follows clonal expansion and activation

Memory Cells

- theory that describes how the immune system identifies, catalogues, and fights specific antigens

Clonal Selection Theory