1. SPECIFIC IMMUNITY BIOL-261 Microbiology

2. I. Four Types of Specific Immunity

• Definition of specific immunity: The immunochemical process of recognizing and destroying specific foreign cells or substances.

• NATURALLY ACQUIRED ACTIVE IMMUNITY produced when foreign antigens enter the body. Two types:

• 1. Humoral Immunity - elicits the production of antibodies against antigens.

• 2. Cell Mediated Immunity - triggers specialized lymphocytes (T- cells)

3. B. NATURALLY ACQUIRED PASSIVE IMMUNITY

• Breast Milk IgA ( a type of antibody) and monocytes.

• Colostrum contains bifidus factors, antibodies that protect the newborn gastrointestinal tract.

• IgG a type of antibody that is transplacental and protects the infant up to 3 months.

4. C. ARTIFICIALLY ACQUIRED ACTIVE IMMUNITY

• Immunity provided by vaccination.

• Examples include:

• (DTP) Diphtheria Tetanus Pertussis

• (MMR) Measles Mumps Rubella

• Polio

• (HIB) Haemophilus Influenzae type B

• Chicken Pox

• (HBV) Hepatitus B Virus

5. D. ARTIFICIALLY ACQUIRED PASSIVE IMMUNITY

• The method of collecting IgG from an infected immune person, and transferring this immunity to an unprotected person. Sometimes given to infants who are not producing enough antibodies.

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7. II. THE LYMPHATIC SYSTEM

• A. PRIMARY LYMPHATIC ORGANS

• • Bone Marrow hematopoietic stem cells produce leukocytes, thrombocytes, and erythrocytes.

• • Thymus specialized lymphocytes called T- cells are made in this glandular structure present in young vertebrates at the base of the neck.

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10. Formation of B and T Cells

11. B. SECONDARY LYMPHATIC ORGANS

• Lymph nodes hundreds of small finger tip sized structures that contain lymph. Loaded with T cells and Follicular Dendritic Cells.

• Spleen mostly B cells. Recovers materials from old erythrocytes.

• Liver mostly fixed macrophages (Kupffer cells)

• Adenoids and Tonsils mostly B cells

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13. Bovine lymph node

14. Spleen

15. Kupffer cells (phagocytes in the liver)

16. Kupffer cells phagocytizing ink (Rabbit liver) Central vein Hepatic or Liver cells Kupffer cell GA F 07

17. Tonsils / Adenoids They in effect act as lymph nodes capturing microbes and processing them.

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• Humoral Immunity

• Definition - the production of specific antibodies against foreign cells or substances.

19. B. What is antibody?

• Antibody is produced in response to antigens. Antibody ( immunoglobulin ) protects against bacteria, exotoxins and viruses. Antibody is circulating in blood plasma, lymph or mucus.

20. C. What is the main function of antibody?

• 1. To neutralize viruses and toxins

• 2. To agglutinate and prevent adherance of bacteria

• 3. To enhance phagocytosis (opsonization)

• 4. To activate complement (most notably, C3a for inflammation, C3b to enhance phagocytosis and C5a for chemotaxis.

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22. D. The Five Classes of Antibodies

• 1. IgG gamma globulin, 75% of all antibody in blood. Responsible for secondary immune response. Variety of functions.

• 2. IgM 10% of antibody in blood. Responsible for primary immune response. Pentamer in structure. Effective at clumping antigen.

• 3. IgA 15% of antibody in blood. Effective in secretions with lysozyme. Found in mucus, colostrum, tears and saliva.

• 4. IgD- < 1% in blood. Found on surface of B cells. Triggers humoral immunity.

• 5. IgE -