EXAM 4

11/18/24


  • IMMUNITY

    • Cells involved

      • Basophils

        • Helps attack large parasites like worms

      • Mast cells

        • Release histamines

      • B cells

        • Make antibodies

      • T cells

        • Attack cells 1 on 1

        • Kills cells

      • NK cells

        • Patrol our bodies constantly

        • Look for any abnormalities and kills them


Definitions


Normal Microbiota

  • Must be present in our bodies to prevent pathogen from taking over

IMMUNITY FACTORS

Physical

Chemical

Skin

  • Dermis: inner portion of connective tissue

  • Epidermis: outer layer of skin cells

Mucus membranes

  • Protect cavities from drying out


Hematopoiesis

  • Monocytes

    • Part of our myeloid stem cell lineage

    • Immature phagocytic cells that mature into some type of macrophages

      • Wandering macrophages

      • Specified macrophages

  • Dendritic cells

    • Macrophages


Formed elements in blood


The Lymphoid System

  • Lymph tissue: where interaction of pathogen and T and B lymphocytes occurs

  • Lymph nodes allow cells that need to work together come together

    • Macrophages and dendritic cells bring pathogen to lymph nodes and tissues


MECHANISM of Phagocytosis

  • Chemotaxis

    • Chemical signals attract pathogens

  • Adherence

    • Recognize specific pathogen attached to antibody and digests that complex

    • Opsonization

  • Ingestion

  • Digestion

    • Oxygen radicals

    • Meet up in phagolysosome and get destroyed


PHASES of Phagocytosis


Inflammation


Vasoactive Mediators of Inflammation


Process of Inflammation


Fever


The Complement System

Triggered by 3 pathways

PATHWAYS

Classical

Alternative

Lectin

  • Complement protein 1

    • Recognizes antibody

  • Must have antibodies in system to recognize pathogens

  • C3A and C3b are essential components to drive all pathways

  • We make sugar binding protein that recognizes sugar on pathogens

  • Triggers complement proteins to get to essential part


Complement Activation

Results in three features of inane immunity

  • Cytolysis

    • C3b will nonspecifically bond to pathogens

    • Macrophages are attracted to c5a

      • Why they are attracted to the site\

  • Opsonization

  • Inflammation 


Interferons

  • Useful for treating viral diseases

  • Makes cells not recognizable so they cannot replicate


Iron-Binding Proteins


Antimicrobial Peptides

FUNGI AND PROTOZOANS


Chapter 21 - Skin Diseases

Fungi that invade keratinized tissue (epidermidis) are called dermatophytes which lead to dermatomycoses.


  • Ringworm - Tinea corporis, T. cruris, T. capitis, T. unguium are all contagious and usually one comes in contact with the organism from unclean environments and fomites. All can be treated with antifungal drugs but it may take many weeks. With T. pedis, one can get a secondary bacterial infection.

    • Really contagious

    • Shows up in unclean environments

    • Picked up in shower areas or gym areas

    • Could get contact through fomite

    • Can lead to secondary bacterial infection due to open wound on skin


OPPORTUNISTIC FUNGAL INFECTIONS

  • Candidiasis - Candida albicans is part of the normal flora. It can cause thrush, vaginitis, infect tissues and is the most common nosocomial fungal infection. Possibility of a systemic infection in immunocompromised people.


  • Candida albicans is part of normal flora of mouth and vagina

  • If it is locally it is ok, systemic is bad because it is hard to treat


  • Candida auris - is an emerging fungal infection causing worldwide concern. It is a serious infection in hospitalized patients which often enters the bloodstream and spreads throughout the body. It is highly resistant to antifungal drugs. Special laboratory methods are used to identify it.


  • Emerging fungal infection

  • Does not behave like candida albicans

    • Hard to grow up

  • Can be found all over the hospital

  • Developed special lab media to identify

  • Highly resistant to antifungal drugs


Chapter 26 - Reproductive System Diseases


  • Vulvovaginal Candidiasis - most cases caused by Candida albicans. It is an opportunistic infection which can occur with uncontrolled diabetes, change in pH, hormone change, and long-term antibiotic therapy.


  • Anything can cause organism and try minor infection

  • Very treatable


  • Trichomoniasis - caused by a protozoan (Trichomonas vaginalis) which is transmitted sexually. It infects the urogenital tract surfaces in both males (rarely have symptoms) and females. Many cases are asymptomatic. T. hominis and T. tenax are normal commensals in our body.

    • Protozoan cell

    • Does not have symptoms mostly in males

    • May be secretion of mucus in females

    • Tenax is in mouth

    • Hominis in intestinal tract

    • Can be part of our normal flora but not in everybody’s flora



Chapter 24 - Respiratory Diseases


  • Coccidioides immitis - Coccidioidomycosis

    • Spores are part of mating cycle of fungal cell

    • If you breathe in spores, symptoms are usually mild or none at all

    • Spherules used as diagnosis


  • Histoplasma capsulatum - Histoplasmosis

    • Endemic in central and eastern part of country

    • Fungal spores are in soil

      • Breathed in

      • Can start the life cycle of vegetative like cell

      • CAN SURVIVE MACROPHAGES

    • Can spread if not fought with good immune response and cause severe damage


  • Pneumocystis jirovecii (carinii) - Pneumocystis pneumonia (PCP)

    • Infects mostly immunocompromised

      • Caused a large number of cases to be seen in young people that had HIV

    • Have to be treated with antifungal drugs

    • Lung infection that can become systemic


  • Blastomyces dermatitidis - Blastomycosis

    • Usually caused by cut

    • Can also be caused by spores

    • Can be spread by macrophages and become systemic


  • Aspergillus fumigatus - Aspergillosis

    • Easily exposed in decaying vegetation

    • Fungus releases long extensions of hypha that compromises lung

      • Walls of tangled hyphae and crippled breathing

    • More common in immunocompromised



Chapter 25 - Digestive System Diseases


  • Giardia duodenalis (intestinalis or lamblia) - Giardiasis

    • Infects intestine

    • Protozoan organism

    • Get it from drinking or eating cysts of organism

      • Equivalent to spore

      • Stays out in environment (can be found in water and stuff)

    • If ingested, it matures in small intestine

    • Discs will cover whole intestinal lining if not treated

      • Prevents absorption

      • Interrupts intestinal tract

      • Causes diarrhea and loss of water

    • Cysts are not killed with chlorination


  • Entamoeba histolytica - Amebiasis (Amebic dysentery)

    • Is an amoeba

    • Exposed through cysts that mature in intestine

    • Can cause a lot of damage to intestinal lining

      • Can reach the lining and all the fecal material can leave

    • Cysts are not killed with chlorination

    • Can remain chronic in some people


  • Cyclospora cayetanesis - Cyclosporiasis

    • Common contaminant in berries

    • Seen in schools

    • Is limiting

    • Oocytes 

  • Cryptosporidium hominis or parvum - Cryptosporidiosis

    • Can be contracted from water contamination


  • Visceral Leishmaniasis

    • Can spike in immunocromised and sand fly area

  • Malaria

    • Found in tropical areas

    • Get released from liver

    • Has different stages

    • Serious in young kids

    • Vaccine not great, not long lasting



Adaptive Immunity

  • Different than innate

  • Targets pathogen after exposure

  • Has specificity

    • Very specific response

  • Based on memory

    • Responds to pathogen very quickly



  • B cells found in bone marrow

  • Can be found in blood too

  • Releases antibody


  • T stands for thymus

    • Goes into blood and lymph tissue

  • T cells

    • Regulate our immune system

  • T cytotoxic cells

    • Respond directly to intracellular viruses

      • Rickettsia 

      • Bacteria

    • Takes care of it 1-1 directly

  • Hypersensitivity T cells

    • Help macrophages

    • Secrete factors that allow them to find cells to engulf


  • Chemokines lure to site of infection

  • Interleukins help leukocytes communicate

  • Interferons get secreted and make antiviral proteins for neighboring cells

  • TNF involved in inflammatory response

  • Hematopoietic cytokines control red and white blood cells


  • Depends on sequence of regions on antibody


  • IgG protects baby during development


  • 5 monomers come together

  • Balance of 10, can pick up up to 10 antigens

  • Remain in the blood due to size


IgA

  • Helps b cells identify antigens


Made in small amounts


  • Treats large worm infections

  • Affiliated with allergies




CD4 T cells

  • Cytokine sygnaling with B cells

  • Bind MHC class II molecules on B cells and APCs


CD8 T cells

  • Cytotoxic through MHC class I proteins on all of our nucleated cells

  • Can see the problem area through MHC I complex


  • Look for any cell with the particular antigen to kill


T Helper Cells

  • T Helper 1 cells

    • Release cytokines that work with macrophages and help them

    • Involved with hypersensitivity responses

  • T helper 17 cells

    • Help with autoimmunity problems

  • Memory cells associated with all the T cells

  • Help with T lymphocytes


  • Cytokines get released


  • T regulatory cells

    • Helps regulate our immune responses

      • Suppress responses when no longer needed

    • Helps us to ignore our normal flora to not attack it


  • Immune response

    • IgM response made

    • Class switching

    • Keep a few of the B cells for memory

    • Secondary response

      • Memory B/T cells pull up

      • Do the job and kill antigen

      • Concentration of IgM is much greater


Vaccines


  • Variolation: smallpox prevention procedure

  • Vaccination: termed by Pasteur


  • Vaccine: suspension of organism that induce immunity

    • Provokes primary immune response

    • Produces rapid and intense secondary response

    • Herd immunity: immunity in most of the population


Types of Vaccines

  • Attenuated

    • Weakened pathogen, reduced virulence

    • Risk going back to the wild form of organism

  • Inactivated

    • Killed vaccine, microbes are inactivated

    • Safer than attenuated vaccines because no risk of mutation

    • Require booster doses

    • Induce humoral immunity

  • Recombinant vaccines

    • Produced by genetic modification of yeast or insects

      • Hep B: capsid grown in recombinant yeast

    • Little to no side effects

  • Toxoids

    • Inactivated toxins

      • Diphtheria toxin, tetanus toxin

  • Virus-like particle vaccines

    • Resemble intact viruses but with no genetic material

      • HPV vaccine

  • Polysaccharide vaccine

  • Conjugated vaccine

  • DNA vaccines

    • DNA injected and rely on mRNA being made to get translated into protein

  • mRNA vaccine

    • mRNA injected into muscle and synthesizes encoding of antigen



Diagnostic Immunology

  • Sensitivity: probability of test being reactive as true positive

  • Specificity: positive test will not be reactive


  • Specificity can recognize antigen on cancer cell

    • Can attach either radioactive molecule or bacterial toxins

  • Hybridoma: immortalized cell line produces monoclonal antibody

    • Can grow up loads of antibody

    • Enough to make magic bullets

    • No contamination by any other antibodies

    • Highly specific

    • Used in cancer therapy


  • Used in diagnostic setting


12/9/24


  • Vaccines have increased our lifespan tremendously

  • KNOW ELISA


Chapter 19

  • Our immune system is educated by our normal flora

    • Important to learn about flora

  • Kids that were exposed to antibiotics very young, they can be treated by obtaining normal flora


  • Four types of hypersensitivity

    • Can cause anaphylaxis and death

  • We should be exposed to organisms early in life to educate our flora



LOOK AT SLIDES FOR REACTIONS

  • Type 1

    • IgE response

    • Serious when systemic

    • Anaphylactic

    • As soon as antigens attach to IgE, degranulation happens

    • Mast cells and basophils undergo degranulation (IgE antibodies bind to cells)

      • Secrete things in inflammatory response

      • Leukotrins are released

      • Prostaglandins cause mucus secretions

    • Hypersensitivity is caused by abnormal release by all these factors


  • Desensitization

    • IgG acts as neutralizing and blocking antibody

    • Grabs pollen before it attaches to basophils and mast cells

    • T cells may be stimulated and can suppress IgE response so IgG can work


  • Some people can have different carb antigens

  • Blood type antibodies and discrepancies 

  • Also involve Rh factor antigen

    • Mother sees some of second babies blood and attacking the baby

      • IgG antibody crosses the placenta


  • Immunocompromised

    • Reaction to your own cells

  • Attract macrophages which cause abnormal inflammatory response


  • May take 24 hours to see symptoms

  • Only involving our T-cells

    • Help macrophages

    • T cytotoxic cells

  • Mounted an immune response to antibiotic unless you come in contact with it again

    • Memory T-cells start to respond

  • Antibodies have rly nothing to do with it


  • Tumor cells secrete things that inhibit immune cells


  • Tumor necrosis factor can be released from infection which shrinks tumor

  • Can be protected from certain cancers by enhancing the immune response through therapies that stimulate the body's natural defenses.