INTRO TO INTERNAL DEFENSE MECHANISM

immunology

• study of the reaction of a host when foreign substance are introduced into the body

• study of all aspects of the body defenses, such as antigens and antibodies, allergy and hypersensitivity

variolation or inoculation

• method of scratching the skin and applying pulverized powder from a small pox scab

attenuation

• involves the use of bacteria or viruses that have been weakened through exposure to modifying conditions such as chemical treatment, hot or cold temp, aging, and repeated in vitro passage in cell culture

vaccine

• is an antigen suspension derived from a pathogen

• routinely administered to healthy individuals to stimulate an immune response to an infectious disease

• a form of immunoprophylaxis, or the prevention of disease through immunization

vaccinia

• pertains to cowpox

variola major

• pertains to small pox

variola minor

• pertains to alastrim

attenuated

• live pathogens that have been weakened by growth under modified culture conditions

• induce both humoral and cell mediated immunity, effective in inducing immunity after a single dose

• bcg, typhoid fever, oral polio, measles, mumps, german measles, chicken pox, rotavirus, yellow fever

inactivated

• killed microorganisms

• can safely be given to immunocompromised individuals

• intramuscular polio (salk), influenza (im or id), rabies

toxoids

• bacterial toxins that have been chemically inactivated so that they are not pathogenic

• induces an immune response to the pathogenic components of a microorganism, safer than administration of an intact organism

• diphtheria tetanus

purified components

• biochemically purified components of a microorganism

• similar with toxoids, produces fewer side effects than whole bacteria

• pertussis (whooping cough)

polysaccharide

• biochemically purified polysaccharide from bacterial capsule

• same with toxoids

• s. pneumoniae, h. influenza type b, n. meningitis

recombinant antigen

• protein produced by genetically modified nonpathogenic bacteria

• highly purified protein that is safer than administration of intact organism

• hepatitis b, hpv

Edward Jenner (1798)

• an english countryside physician demonstrated that protection from cowpox could be generated by the transfer of postural material from a cowpox lesion instead of the more hazardous smallpox lesion

louis pasteus (1880)

• demonstrated that injection of killed microbes provided protection upon subsequent exposure to live counterpart

ellie metchnikoff (1888)

• demonstrated that certain blood cells ingest foreign material - (phagocytosis)

jules bordet (1894)

• discovered complement and initially called it “alexin”

• paul ehrlich - coined the term complement

robert kaus (1897)

• discovered precipitins

emil von behring (1901)

• had the distinction of being awarded as the first immunology related nobel prize for his works on serum therapy

1984

• discovery of the t cell receptor gene

susumu tonegawa (1987)

• was awarded the nobel prize for his 1978 discovery of the genetic principles underlying the generation of antibodies with different specificities

innate or natural immunity

• individuals’s ability to resist infection by means of normally present body functions

• these are considered non adaptive or non specific and are the same for all pathogens or foreign substances to which one is exposed

• no prior exposure os required and the response lacks memory and specificity

• many of the mechanisms are subject to influence by such factors as nutrition, age, fatigue, stress, and genetic determinants

acquired immunity

• a type of resistance that is characterized by specificity for each individual pathogen or microbial agent

• the ability to remember a prior exposure which results in an increased response upon repeated exposure

external defense system

• which is composed of structural barriers that prevent most infectious agents from entering the body

• unbroken skin and the mucosal membrane surfaces, lactic acid in sweat and acidity in GIT and Vagina, cilia lining in respiratory tract, the flushing action of urine

mechanical barrier

• skin, mucous membrane, cilia, mucus

• peristaltic movement of intestine

• shedding of cells

• coughing and sneezing

• flushing action of urine

chemical barrier

• enzymes like lysozyme found in secretion, lactic acid in sweat

• hcl in the gi tract

• acid in urine

biological barrier

• skin and mucous membrane

• normal flora

internal defense system

• which both cells and soluble factors play essential parts

• is designed to recognize molecules that are unique to infectious organisms