ISLAB-IMMUNITY

• IMMUNITY

  • body's ability to prevent the invasion of pathogens or resist harmful microorganisms.

  Types

  • Innate = already present in the body; non-specific; rapid; limited and lower potency; no memory; allergic reaction
  • Adaptive = created in response to exposure to a foreign substance; specific; slow (1-2 weeks); high potency; long-term memory; immediate and delay hypersensitivity
• NATURAL VS ADAPTIVE

  • Natural (Innate) = nonspecific; no memory; examples are exogenous (skin), endogenous (stomach acid), phagocytosis (PMNs), natural killer cells
  • Adaptive (Acquired) = specific; memory; examples are T cells (cytokines), B cells (antibodies)
• INNATE IMMUNITY

  Physical

  • skin
  • cough reflex
  • tears (enzyme in tears)
  • mucosal layer
  • stomach acid

  Phagocytes

  • monocytes
  • macrophages
  • neutrophils
  • NK cells
  • dendritic cells
• ADAPTIVE IMMUNITY

  T-Lymphocytes

  • helper
  • suppressor
  • cytotoxic

  B-Lymphocytes

  • clonal
  • memory
• ACTIVE VS PASSIVE IMMUNITY

  Active

  • individual produces antibody
  • follows immunization or infection
  • memory (lasting)
  • stimulate the body's immune system
  • antibodies or cell-mediated immunity, or both, which protects against infectious agent.
  • Examples = vaccines or toxoids
• ACTIVE VS PASSIVE IMMUNITY

  Passive

  • antibody transferred to individual
  • example = gamma globulin, injections, placental transfer
  • no memory (temporary)
  • consists of providing temporary protection through the administration of exogenously produced antibody
  • Examples = transplacental (protective for first 3-6 months of life); immunoglobulin injection (for specific purposes)
• NATURAL IMMUNITY

  Natural Active

  • immunity after infection
  • person is exposed to a live pathogen, develops the disease, and becomes immune as a result of the primary immune response.
  • bacteria, virus, toxins
  • B-cells and T-cells will attack the antigen
• NATURAL IMMUNITY

  Natural Passive

  • transplacental transfer of IgG
  • immunoglobulins in milk (breastfeeding)
  • type of natural immunity in the form of antibodies from a mother to her fetus across the placenta or through her milk
  • last for a short period of time only
• ARTIFICIAL IMMUNITY = immune response that develops antibody from exposure to a specific antigen.

  Artificial Active

  • vaccination
  • antigen is presented and antibodies will fight and remain alert for future infection

  Artificial Passive

  • immunity comes from infected antibodies created within a different person or an animal.
  • immunoglobulins or antisera and anti-toxins.
• IMMUNIZING AGENT

  • substances or organism that provokes an immune response (produces immunity) when introduced into the body.

  Different kinds:

  • Vaccines = suspension of attenuated live or killed microorganisms administered to induce immunity and thereby prevent infectious disease.
• IMMUNIZING AGENT

  Different kinds:

  • Immunoglobulins = contains 15-18% protein obtained by cold ethanol fractionation of large pools of blood plasma.
  • primarily indicated for certain immunodeficient persons, passive immunization against measles and hepatitis A, and special IV preparations for immunoglobulin deficient patients.
  • Antisera = blood serum containing monoclonal or polyclonal antibodies that is used to spread passive immunity to many diseases.
• VACCINES

  • antigen administration to stimulate production of specific antibodies to protect individual against particular disease.

  Characteristics

  • Safety = no disease must be caused by the vaccine itself.
  • Protection = must be at the population level and prevent disease when the infectious agent is encountered.
  • Long lasting effects = induce T and B cell memory
  • Cost = inexpensive to produce and deliver
  • Administration = easy to deliver with no side effects.
• ANTISERA AND ANTITOXINS

  • specific immunoglobulins prepared from the plasma of immunized animals or humans.
  • cheap but less effective.
  • lasts only for a short period of time.
  • Examples = snake venom, anti-tetanus, rabies vaccine
• IMMUNOGLOBULINS

  IgG

  • greatest concentration in serum
  • 4 subclasses = IgG1 to IgG4
  • Activates complement (except for IgG4)
  • crosses placenta
  • 75% of total antibody concentration
• IMMUNOGLOBULINS

  IgM

  • largest antibody (pentamer)
  • fixes complement best (multiple binding sites)
  • prominent in early immune response (indicates acute infection)
  • 5-10% of total antibody concentration
• IMMUNOGLOBULINS

  IgA

  • predominant antibody in body secretions (tears, saliva, nasal mucosa)
  • serum IgA (monomer) and secretory IgA (dimer)
  • primary defense against local infections at mucosal surface
  • two subclasses
• IMMUNOGLOBULINS

  IgD

  • unknown function
  • present on B cell surface

  IgE

  • allergy
  • type 1 hypersensitivity
  • involved in release of histamines from mast cells
• CONSTITUENTS OF IMMUNIZING AGENTS

  Suspending Fluid

  • this frequently is as simple as sterile water of saline
  • may be a complex fluid containing small amounts of protein or other constituents derived from the medium or biologic system in which the immunizing agent is produced (serum proteins, egg antigens, cell culture-derived antigens)
• CONSTITUENTS OF IMMUNIZING AGENTS

  Preservatives, Stabilizers, Antibiotics

  • to inhibit or prevent bacterial growth in viral culture or the final product
  • to stabilize the antigen
  • allergic reactions may occur if the recipient is sensitive to any of these additives
• CONSTITUENTS OF IMMUNIZING AGENTS

  Adjuvants

  • enhances the immune response to vaccines containing inactivated microorganisms
  • can be in a form of aluminum salt or oil-in-water adjuvants