Inflammation Flashcards
Pathogens
s any foreign organism (not a part of the body) that invades or is
present inside the body.
* can cause harm to the body and affects normal functioning.
* can cause disease
Differences in below:
- Viruses
- Bacteria
- Fungus
- Parasite
Virus: non-living particles with RNA or DNA only & rely on living cell, Eg: Cold, flu, HIV, chicken pox, COVID, gastroenteritis
Bacteria: Single-cell organism without a nucleus own survival and reproduction. Eg: TB, Cholera, pneumonia
Fungus: Single cell organism including and yeast that grow as single cells or thread like filamensts. EgL Ringworms, candidiasis
Parasite: Single cell organism with a nucleus that lives in host organism at expense of host. Eg: Malaria
Antigens?
antigen = antibody generator
is not an organism, but rather, a molecule attached to a foreign organism that activates an antibody response
Antigen site
usually located in the cell walls of bacteria, or in the outer coating of other foreign organisms.
- can also be an unusual peptide produced by a tumor cell.
Why is the immune system non-reactive against self-antigens?
The immune system is usually non-reactive against “self” antigens under
normal homeostatic conditions due to negative selection of immune cells
in the thymus and is supposed to identify and attack only “non-self”
invaders from the outside world or modified/harmful substances present
in the body under distressed conditions.
Negative selection and self-tolerate
Negative selection deletes potentially self-reactive immune cells, thereby
generating a repertoire of immune cells that is largely self-tolerant
Different physical barriers and its role in protecting the body
against foreign pathogens
START TOP GOING DOWN
- Tears (First line of defense)
-Wash away irritating substances and microbes
-Lysozyme kills many bacteria - Saliva
-Washes microbes from the teeth and mucus membranes of the mouth - Skin
-Provides a physical barrier to the entrance of microbes
-Acidic pH discourages the growth of organisms
-Sweat, oil and fatty acid secretions kill many bacteria - Respiratory tract
-Mucus traps organisms
-Cilia sweep away trapped organisms - Stomach
-Acid kills organisms - Large intestine
-Normal bacterial inhabitants keep invaders in check - Bladder
-Urine washes microbes form urethra
Describe the cells of the immune system and the role and function in the
immune response
Never Let Dead Monkeys Eat Moist Bananas
Neutrophils
Lymphocyte(NTB)
Dendritic
Monocyte/Macrophages
Eosinophil
Mast
Basophil
Neutrophils
*Short-lived cells ~ 5 days
* Phagocytes
* Antigen-presenting cells to memory T helper cells.
* Destroy microorganisms with granules (contain lysozyme &
other degradative enzymes).
* Release neutrophil extracellular traps (NETs).
* Very effective at killing bacteria.
Types of lymphocytes?
- T-cell
- NK-cell
- B-cells
Types and functions of T-cells?
- Killer/Cytotoxic T Cell (TC):
Destruction of host cells infected with viruses or other
intracellular pathogens - Helper T Cells (TH):
Directs the immune system by secreting cytokine - Memory T Cells (TM)
Provide long–lasting immunity - Suppressor/Regulator T Cells (TS/R) Suppress activity of other lymphocytes to control immune responses
Dendritic?
- Live for days to weeks.
- Phagocytes
- Long finger like processes: ingest particles and
extracellular fluid by macropinocytosis. - If they encounter a microorganism, they
mature into cells capable of activating T
lymphocytes = Antigen presenting cells
Monocytes/Macrophages?
- Monocytes live for 1-3 days in blood
- Macrophages live for a long time (months) in tissue
- Phagocytes
- Antigen presenting cells
- Orchestrate immune responses: induce inflammation, secrete signaling proteins (cytokines) to activate
lymphocytes and other phagocytes.
Monocytes/Macrophages?
- Monocytes live for 1-3 days in blood
- Macrophages live for a long time (months) in tissue
- Phagocytes
- Antigen presenting cells
- Orchestrate immune responses: induce inflammation, secrete signaling proteins (cytokines) to activate
lymphocytes and other phagocytes.
Mast cell?
- Reside in tissue mainly near small blood vessels.
- Function is similar and complementary to that of
eosinophils and basophils. - Release histamine and heparin which are involved in
inflammation. - Phagocytes
- Are involved in allergic responses.
Basophils?
- Function is similar and complementary to that of
eosinophils and mast cells. - Release histamine and heparin which are involved
in inflammation. - Heparin initiates the production of a hormone –
bradykinin - Bradykinin causes dilation of blood vessels
- Histamine increases vascular permeability
- Phagocytes
- Are involved in allergic responses
Eosinophils ?
- Involved mostly in defense against parasitic infections.
- Secrete highly toxic proteins and free radicals that are
highly effective in killing bacteria and parasites. - Phagocytes
- Along with mast cells causes Inflammation and is
involved
B-lymphocytes?
- Each B cell carries a different antigen receptor (B cell receptor) on its surface.
- B cell receptor (BCR) is a surface antibody (or immunoglobulin)
- When BCR binds to its antigen it activates the B lymphocyte
- Activated B cells multiply and
differentiate into plasma cells or memory cells. - Plasma cells produce antibodies Natural killer (NK) cell
- Involved in the early phase of host defense to pathogen.
- Have the capacity to recognize the surface changes that occur on a variety of
tumor and virally infected cells. - Unlike killer T cells, they do not have antigen-specific receptors.
- “Killing” method same as that of Killer T cells.
- Release granules that kill some virus-infected cells by causing lysis of the infected cell. Lysis refers to the
disintegration of a cell by disruption of its
plasma membrane. - Secretes cytokines
Cytokine: immunoregulatory proteins important in cell signalling –any of a number of substances, such as interferon, interleukin, and growth
factors, which are secreted by certain cells of the immune system and have
an effect on other cells.
Natural killer cell?
- Involved in the early phase of host defense to pathogen.
- Have the capacity to recognize the surface changes that occur on a variety of
tumor and virally infected cells. - Unlike killer T cells, they do not have antigen-specific receptors.
- “Killing” method same as that of Killer T cells.
- Release granules that kill some virus-infected cells by causing lysis of the
infected cell. Lysis refers to the
disintegration of a cell by disruption of its
plasma membrane. - Secretes cytokines
Cytokine?
Immunoregulatory proteins important in cell signalling-any of a number of substances, such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system and have
an effect on other cells.
Immune system organs?
Look at diagram
Lymphoid tissue
Produce store and process lymphocytes
Types of lymphoid tissue?
- Bone marrow
- Lymph nodes, tonsil, adenoids, appendix, GALT
- Spleen
- Thymus
Bone marrow
- Origin of all blood cells
- Site of maturational processing of B lymphocytes
Lymph nodes, tonsil, adenoids, appendix & GALT
- Exchange lymphocytes with the lymph(remove, store, produce and add them)
- Resident lymphocytes produce antibodies and activated cells which are released into the lymph
- Resident macrophages remove microbes and other particulate debris from the lymph
Spleen
- Exchanges lymphocytes with the blood(removes, stores, produces and adds them)
- Resident lymphocytes produce antibodies and activated cells which are released into the blood
- Resident macrophages remove microbes and other particulate debris, most notably worn-out red blood cells, from the blood.
Thymus
- Site of maturational processing for T-lymphocytes
- Secrete the hormone thymosin(stimulates the development of T-cells)
The different pathways of innate immunity
and its role in the
immune response
- Monocyte-macrophage pathway
- The complement system
Can co-exist simultaneously
Monocyte-macrophage pathway?
Activated when signal between CD4 and hep, the cells occurs
Cytokines activated macrophages secrete a range of cytokines?
IL-1B
IL-6
TNF-alpha
CXCL8
IL-12
The three complement system?
- The classical complement pathway
- The lectin pathway
- The alternative complement pathway
Complement pathway?
Understands
Difference between primary and secondary immune response
Refer to table on page 18
Function of lymphocytes of acquired immunity?
?
Interaction between the innate and acquired immune system
?
Signal transduction?
The process by which a cell responds to substances outside the cell through signaling molecules found on the surface of and inside the cell.
Major plasma membrane receptors?
?
Role of receptor activation?
?
Explain the generation of second messengers?
?
Difference between protein-based and nucleic acid-based molecular tools/techniques?
Protein is a molecule made up of polypeptides. It is a class of biological molecule consisting of chains of amino acids called polypeptides. Nucleic acid is a class of macromolecules made up of long chain of polynucleotide that includes deoxyribonucleic acid (DNA) and ribonucleic acid (RNA
Serologic tests?
Serologic tests are blood tests that look for antibodies in your blood
Which kind of symptoms are for serologic tests?
For patients who present at their doctor with symptoms suggestive
of bacterial, parasitic, and viral diseases
What is the common factor between the laboratory techniques for serological tests?
They can involve a number of laboratory techniques but have one thing in common = focus on proteins made by your immune system.
What is the significance of serologic tests?
*When your doctor tests your blood, they can identify the type of antibodies and antigens that are
in your blood sample, and identify the type of infection you have.
* Sometimes the body mistakes its own healthy tissue for outside invaders and produces
unnecessary antibodies, which is known as an autoimmune disorder.
* Serologic testing can detect these antibodies and help your doctor diagnose an autoimmune
disorder from a single blood sample = high CRP levels for rheumatoid arthritis
Serological tests diagnostic method?
- Hemagglutination inhibition test
- Immunoassays
Hemagglutination inhibition test
- Basically hemagglutination occurs when there is antibodies/viruses
- No hemagglutination occurs when there is no virus or it shows exposure and indicates immunity
Serological test: immunoassays?
In immunoassays, antibodies binding to specific immobilized antigens can directly
be observed using bound antigens and indicators such as labeled anti-Ig
antibodies.
What do immunoassay’s measure?
Different immunoassays are widely used to measure IgM and IgG antibodies
Principles of immunoassay’s?
?
When are immunoassays called ELISA?
If the label used is an enzyme, the test is called enzyme-linked
immunosorbent assay (ELISA) and the bound antibody is
detected by an enzyme-dependent color reaction.
When are immunoassays called IFT?
If a fluorescent label is used, the method is called
immunofluorescent test (IFT)
What are enzyme labels called?
The enzyme labels most commonly used are horseradish peroxidase (HRP) and alkaline phosphatase (AP
HRP-ELISA substrate and chromogen?
In HRP-ELISA the color-forming system consists of ortho-
phenyldiamine (OPD) as a chromogen and hydrogen
peroxidase (H2O2) as a substrate.
Self tolerance?
Proper functioning of the immune system. It is the ability of the immune system to recognize self-produced antigens as non-threats while appropriately mounting a response to foreign substances.
Able to differentiate between foreign and self-antigens
Factors in the loss of self-tolerance?
- Presentation of self-antigens
- MHC and genetic susceptibility
- Autoreactive T cells and B cels
- Presence of costimulatory molecules
Costimulatory molecules
In essence, the co-stimulatory molecules function as “flashing red lights” that interact with the T cell, communicating that the material being presented by the dendritic cell material indicates danger
Mechanisms of the tolerant state?
- Central tolerance
- Peripheral tolerance
- Clonal anergy
Central tolerance?
Elimination of T-cells and B via apoptosis with any reaction with self-antigens
Peripheral tolerance?
Elimination of immature and autoreactive T-cells and B via apoptosis with any reaction with self-antigens
Clonal Anergy?
Activating any immune cells that bypass the clonal deletion
Autoimmunity ?
Loss of self-tolerance as the body’s immune system starts to destroy the body
Aetiology of autoimmune disoders?
-Exact aetiology remains unknown
-Genetic predisposition
-Environmental factors
-sex
-hormonal
Pathophysiology of rheumatoid arthritis?
Pathophysiology of SLE?
Systemic consequences of increased circulating inflammatory cytokines in RA and SLE?
HIV?
Pathogenesis of acute HIV infections?
Consequences of HIV infections on the immune system function?
Role of immune system in the development of HIV?
Life cycle of the HIV virus?
Pathogenesis of HAND in HIV?
Pathogenesis of tuberculosis?
Role of the immune system in the formation of granulomas in the lung in tuberculosis ?
Neuroinflammation?
Molecular mechanisms involved in the development of age-related neuroinflammatory disorders?
Neuroinflammatory disorders?
The role of the immune system in the development of major depressive disorder?
