Immune notes
- 1. Immune notes. 1. what are the differences among the three lines of defences. - 1st line- external non-specific. Acidity of skin and the presence of epithelial cells ward off pathogens. - 2nd line- internal non-specific. Presence of cilia, mucus, granulocytes, proteins and phagocytes. - 3rd line- internal specific. Uses lymphocytes (B cells and T cells) 2. If you know the function of these terms then papasakana. a. Epithelial tissue b. Tears, sweat and oils c. Cilia d. Mucus e. Neutrophil f. Basophil g. Eosinophil h. Mast cell i. Dendritic cell j. Natural killer cell k. Monocyte l. Macrophage m. Coelomocyte n. Hemolin o. Complementary proteins p. Interferon q. Antigens r. Antibodies s. Plasma B cell t. Memory B cell u. Suppressor T cell v. Cytotoxic T cell w. Helper T cell Inflammation 1. Starts when histamines are released. Histamines are substances that can cause blockage in a local capillary bed that can result in an inflammatory response. 2. Pathogens and self cells (mast cells and basophils) release histamines. Inflammation is activated by the body to localize the destruction of a pathogen. 3. When histamines are released it can cause the activation of prostaglandins. Prostaglandins affect blood clotting and permeability of blood vessels.
- 2. 4. Prostaglandins will close the post capillary sphincter of an affected area and open its pre- capillary sphincter. As a result a lot of blood will be trapped in that area. The blood vessel’s size will then balloon and this will result in the increase size of the intercellular cleft found in the blood vessel. As the intercellular cleft increase its size the permeability of the blood vessel will then increase. More substances can flow out of the blood vessel. 5. RBC, WBC and platelets will now be able to leak out of the capillary bed. The platelet together with the RBC will initiate blood clotting if the cause of the infection is a wound. Meanwhile, WBCs will act on the pathogens, neutrophils will arrive first followed by macrophages. The neutrophils will explode and the debris will be eaten by the macrophage. The “explosion” of the neutrophils together with the pathogen (antigen) will make it easier for the macrophage to completely destroy it using its lysosome with lysozyme. 6. If the pathogen that entered the body is strong, then, the macrophage will proceed to the third line of defense. Anaphylactic shock If the inflammatory response is too widespread it can result in an anaphylactic shock. This can result in hypotension and severe fever that can result in death. Septic shock (sepsis- blood poisoning through infection) can result in an anaphylactic shock. Fever Body’s defense to denature the protein pathogens or proteins in the cell membrane of pathogens. If the fever is too high, it can denature the body’s cells. Complementary proteins Proteins that are used in the 2nd and 3rd line of defences. Examples are interferons, lysozyme, antibodies. Interferons Warning signal used by virus infected cells to alert nearby cells to activate a possible immune response against the virus. The ID system To launch a specific immune response the body needs an ID system to determine what is a pathogen and what is a self cell. WBCs recognize cells based on a protein found on the cell membrane of a cell, if the protein resembles a self cell then it will not be attacked by the body’s immune system but if the ID represents a foreign body then the body will launch an immune response against it. The protein “ID” is called the major histocompatibility complex protein (MHC) governed by the MHC gene. Transplants, blood donation, etc rely on this system to be effective. The third line of defense -watch the youtube video on humoral and cell mediated response
- 3. Clonal selection Clonal selection is the process of producing clones of specific lymphocytes (B cells and T cells). The results of this are more selective cells that are greater in number and have higher affinity to a specific pathogen. As a consequence, immunological memory is produced. Autoimmune vs immunodeficiency An autoimmune disease is a disease that results from the loss of MHC proteins of your self cells. WBCs will attack your cells once they lose their ID. Immunodeficiency is the result of deactivation of a B cell or T cell or both. An example of this is AIDS, HIV hinders the action of helper T cells to prevent them from activating the humoral or cell mediated response. Passive Immunity vs Active Immunity Passive immunity results from the transfer of an immune factor (antibody, etc) from one person (mother) to another (child). Its specificity is low. Active immunity is produced when a person acquires immunity directly from a disease, either the person got infected (natural) or was administered with a vaccine (artificial) Blood type Blood type is determined through the presence (AB) of antigens on RBCs and its absence (O). The other blood type (Rh factor) Rh +- antigen is present Rh - - antigen is absent The problem, a specific immunoglobulin (Ig) can pass through the placenta of a mother to attack the baby as it considers the baby as a pathogen. This antibody will act depending on the presence and absence of the Rh factor. If a woman with a negative Rh factor marries a man with a negative Rh factor they will not have a problem conceiving because even though the mother has the antibodies the blood of the baby will not have the antigen (negative). If a woman with positive Rh factor marries a man with positive Rh factor there will be no problem as they have the same “ID”. If the woman is positive and the man is negative there will be no problem too because even if they have different Rh factors the mother’s immune system will not recognize the Rh factor of the baby because it does not have an ID on it. The problem lies with a woman with a negative Rh factor having a child with a man with a positive Rh factor. The first baby will elicit an immune response from the mother’s immune system resulting in an immunological memory. The possible second baby might die because the memory B cells against the pathogen (baby) will be activated resulting in the lysis of the baby’s blood (Erythroblastosisfetalis). This can be prevented if the antibody is rendered inactive.