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University of Tabuk Faculty of Applied Medical Science Department of Medical Laboratory Technology. Basic Immunology. Mr.AYMAN.S.YOUSIF MSc.Medical Microbiology & Immunology. Academic Year: 1433-1434 (2012-2013). Arms of Immune System. Innate Immunity.
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University of Tabuk Faculty of Applied Medical Science Department of Medical Laboratory Technology Basic Immunology Mr.AYMAN.S.YOUSIF MSc.Medical Microbiology & Immunology Academic Year: 1433-1434 (2012-2013)
Arms of Immune System Innate Immunity Mr.AYMAN.S.YOUSIF 11-12/02/2013 Lecture 2
Objectives At the end of this lecture, you should be able to: • Recognize the significance of the immune system in combating infection and disease. • know the humoral and cellular components of innate immunity. • Understanding the mechanism of action of the humoral and cellular components of innate immunity. • Understanding the major Function of innate immunity .
Innate (Non specific) Immune System • Also called natural or native immunity. • It is present at birth; provides the early (first) lines of defense against microbes. • Consistsof barriers (defense mechanisms) that are in place even before infection and poised (ready) to respond rapidly to infections. but do not adapt to a particular pathogen (non-specific). • They respond in essentially the same way to repeated infections. (no have memory ).
Antigen recognition byInnate Immunity components • Several components of innate arm recognize what is foreign by • Detecting Certain CHO or lipid on the surface microorganism that are different from those on human cells . • Component of the innate arm have receptor called Pattern-recognition receptor that recognize a molecular pattern on the surface of microbe that is not present on human cells. • This receptors are called Toll-Like Receptor (1-10).
Remember • It is important to remember that infection with an organism does not necessarily mean diseases, due to the immune system in most cases will be able to eliminate the infection before disease occurs. • Disease occurs only when • The bolus (dose) of infection is high. • when the virulence of the invading organism is great . • when immunity is compromised.(Immunecomprmised).
Important Components of Innate Immunity 1. Factors that LimitEntryof Microorganisms Into The Body. A. Anatomical Barriers To Infections. • Mechanical Factors (Barrier) . • Chemical Factors (Barrier) . • Biological Factors (Barrier) . 2. Factors that Limitgrowth of Microorganisms Into The Body. B. Humoral Barriers To Infection. (Humoral components) C. Cellular Barriers To Infection (cellular components )
B. Humoral barriers to infection • The Anatomical barriers are very effective in preventingcolonization of tissues by microorganisms. • when there is damage to tissues, The anatomical barriers are breached and infection is occurs. • Once infectious agents have penetrated tissues, another innate defense mechanism comes into play, namely Acute Inflammation. • Humoral factors play an important role in inflammation, which is characterized by edema and the recruitment of phagocyte cells. • These humoral factors (Soluble factors) are found in serum or they are formed at the site of infection.
progenitors Innate immunitylargely involves granulocytes and macrophages (although macrophages can influence adaptive immunity) Adaptive immunity is mediated primarily by B and T lymphocytes other cells are regulatory or involved with both adaptive and innate immunity and/or are precursors of another cell type
PMNs Polymorphonuclear Neutrophilic Leukocytes, a.k.a., PMNs. They are shorter lived than macrophages but have greater killing power.
Non-Phagocytic Granulocytes Eosinophils are involved in allergic responses, inflammation, and release of Histamine; Histamine is released by Basophils.
Function of Innate Immune System • The Innate arm of our host defenses perform tow major Function . • Killing Invading Microbe . • Activate Acquired (Adaptive) immune processes e.g. Neutrophil only kill microbe . Macrophage (MQ) & Dendritic cell(DC) Kill microbe and present Ag to Components of Acquired immunity specially Helper T cells (CD4) Which activate Acquired immunity