PRACTICAL APPLICATIONS OF IMMUNOLOGY

Outline I. VACCINES

I. History

II. Principles and Effects of Vaccination

III. Types of Vaccines

IV. Development of New Vaccines

V. Safety of Vaccines

II. DIAGNOSTIC IMMUNOLOGY

I. Immunologic-Based Diagnostic Test

II. Monoclonal Antibodies

III. Precipitation Reactions

IV. Agglutination Reactions

V. Neutralization Reactions

VI. Complement-Fixation Reaction

VII. Fluorescent-Antibody Techniques

VIII. Enzyme-Linked Immunosorbent Assay (ELISA)

VACCINES

• suspension of organisms or part of organisms used to induce immunity

•Immune response mimics recovery from disease

Principles and effects of Vaccination

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• How Do Vaccines Prevent Illness_.mp4

Vaccines (cont…)

•Best way to control viral diseases

•HERD IMMUNITY- immunity in most of a population that limits the spread of a disease

Vaccines (history)

• Variolation

• Vaccine- (latin vacca – cow), a suspension of organisms used to induce immunity

EDWARD JENNER (1798)Small pox

TYPES OF VACCINES

TYPES OF VACCCINES

•LIVE ATTENUATED VACCINES

•Closely resemble actual infection

•Typical lifelong immunity

•Problem: live microbe can mutate to virulent form

TYPES OF VACCINES

• INACTIVATED WHOLE-AGENT VACCINES

•Killed microbes

• Formalin and phenol

-Rabies-influenza

TYPES OF VACCINES

•TOXOIDS

• Inactivated toxins

•Boosters are required

•Boosters- supplementary dose of a vaccine

TYPES OF VACCINES

•SUBUNIT VACCINES

•Antigenic fragment

•Virus protein coat

TYPES OF VACCINES

•CONJUGATED VACCINES

•Polysaccharide combined with antigen

•Used in children for early immunization

•Hib Vaccine

TYPES OF VACCINES

•DNA (Nucleic Acid) VACCINES

•Naked DNA inserted thru “Shot gun” method

•West Nile virus vaccine for horses

Routes of Administration

Vaccine summary

• How do vaccines work_ - Kelwalin Dhanasarnsombut.mp4

Diagnostic Immunology

Immunologic-Based Diagnostic Test

• Tests based on interactions of antibodies and antigens to determine the presence of antibodies or antigens in patients

Monoclonal Antibodies

• Technique to make a single type of antibody in unlimited amounts

• Fusion of an antibody producing B cell with a myeloma cell – immortal antibody producing cell

• HYBRIDOMA

• Hybridoma cells produce large quantities of a specific antibody

Monoclonal AntibodiesUses and Problems

• Uses

• Diagnostic

• Pregnancy tests

• Therapeutic

• Transplant rejection

• Cancer treatment – Herceptin

• Problems

• Antibodies are mouse protein and cause reactions in the human body

Monoclonal Antibodies

Precipitin Reactions

•Reaction of soluble antigens with IgGand IgM antibodies

• Form visible molecular aggregates called LATTICES

•Precipitation only occurs where the ratio of antigen to antibody is optimal

Precipitation curve

Precipitation Reactions

Agglutination Reactions

• Form visible clumps or aggregates

• Very sensitive and easy to read

• Direct agglutination tests• Detect antibodies against large cellular

antigens – RBC’s, bacteria, fungi

• Antibody titer

• Indirect agglutination tests• Antigens absorbed onto latex spheres

Agglutination reaction

Direct agglutination

Indirect Agglutination

Viral hemagglutination

Neutralization Reactions

•Antigen-antibody reaction that can block the harmful effects of toxins or viruses

•Neutralizing substance is an antibody produced by the host

•Called an ANTITOXIN

•Antitoxin combines with the toxin and the toxin is neutralized

Fluorescent-Antibody Techniques

•used to identify microorganisms in clinical specimens or antibodies in serum

•Combine antibodies with a fluorescent dye

•Direct FA tests

•Microorganisms in clinical samples

• Indirect FA tests

•Detect antibodies in serum

Enzyme –linked immunosorbent assay (ELISA)

• Antigen- antibody reactions are detected by enzyme activity.

• If the indicator enzyme is present in the test well, an antigen- antibody reaction has occurred.

Enzyme –linked immunosorbent assay (ELISA)

• Direct ELISA

• Detects antigen

• Common use is in drug screening in urine

• Indirect ELISA

• Detects antibodies in patient sample

• Common example is screening blood for antibodies to HIV

Direct and Indirect ELISA

Salamat!