Primary and Secondary Immune Response:
Lectuer-9-
Dr. Baha,H.AL-Amiedie
Ph.D.Microbiology
Primary Immune Response:
Primary Immune Response to initial antigenic stimulus is slow, sluggish, short live with a long lage phase and low antibody titer
that do not persist for along time ,antibody formed are 1gM. When tetans toxoid is given to host an immune response is mounted .The response could be detected intervally by collection blood and estmaton of antbody
titers, it was found that the immune response follows the time curve in which the first day after Antigen injection 10-12 days after the first injection antibody begin to rise in their titer, this stage is known phase of antibody rise. After this stage any blood sample will take the same antibody titer this called platue phase. Within the third 3 week or more the antibody titer in the collection the sample begin to decline , this stage
is called decline phase . The antibody classes start with 1gM followed by IgG and described as Antigen specific response.
Secondary Immune Response:
Secondary Immune Response to subsequent stimuli is prompt, powerful prolonged and with much higher level of antibody it vast for long time,
Antibody predominatly formed are IgG, when boostinge of toxoid is given to the same host the lage phase is reduced. and the antibody rise phase is begin faster than first phase within a week, prescence of memory cell which are specific for antigen, so always if we give multiple dose of the same Antigen to the same host will lead good immune response because of the regulatory mechanisum , within the body for the amount of antibody against Antigen ,The antigen type is in these responses is B-dependent-Antigen .The time carve is follow factor influencing Antibody production:
1. Age
2. Nutritional status
3. Route of administration
4. Size and Number of doses
5. Multiple antigens
6. Adjuvant
7. Immunosuppressive agent
Cellular Immune Response: -
The term cell rnediated immunity refers to the specific immune responses that do not involve antibodies, induction of cell mediated immune response (CMI) consists of specifically sensitizing T-lymphocytes comes against the antigen. When sensitized T-cell comes in contact with antigen determinant (epitopes)by the function of Antigen Presenting Cell (APC) ,so T-cell under goes blast transformation and clonal proliferations selectively in paracortical areas of lymph nodes.
lymphokines: material required as secreted proteins from the activated T-cell , These Lymphokine have several biological function
1-Effect on macrophage : This Lymphokine is function is covered out
by the following:
a-Macrophage inhibition Factor (MIF)
b-Macrophage aggregation Factor (MAF)
c-Macrophage chemotactic Factor (MCF)
2-Effect on Lymphocytes:This role is done by:
a-Blastogenic factor (BF)
b-Potentiation factor (PF)
c-Cell co-operation factor (CE).
3-Effect on granulocyte: •.
a-Inhibition factor (IF)
b-Chemotactic factor(CF)
4-Effect on tissue cultur:
a-Lymphotoxin
b-Proliferation inhibition factor (PIF)
c-Interferon
Table- 1 Interleukines
Immunoglobuline
Or Antibodies
Are glyeoproteins present in the gama- globuline fraction of serum. Immunoglobuline generally natural present in blood without previous antigenic stimulation However antdody are the Immunoglobuline that
Produce specifically by B-cell after antigenic stmulaton . Thus all antibodies are Immunoglobuline while no all Immunoglobuline are antibody
The charateriste of antibody are
1. glycoprotein in nature.
2. specific to antigine induce them.
3. React specifically with their own antigen
Antibody are distributed in serum, body fluid, Urine ,Saliva , Ear wax and tears.
The anitbody molecule are found to be of dfferent classes , the classification depend on :
1-The molecular size
2-Natur of carbohydrate,
3-Amino acid sequnence.
The classes of Antibodiess are IgM, IgG, IgE & IgD.
The dfference between these Classes depend on the type of heavy chain in each molecule, Immunoglobulines mak 20- 25 % of total serum protein, the terum lmmunoglobuline is structural & chemical concept while antibody is biological and function concept.