Summary Artikelen experimental immunology

-
346 Flashcards & Notes
1 Students
  • This summary

  • +380.000 other summaries

  • A unique study tool

  • A rehearsal system for this summary

  • Studycoaching with videos

Remember faster, study better. Scientifically proven.

This is the summary of the book "Artikelen experimental immunology". The author(s) of the book is/are Joke Sandra. This summary is written by students who study efficient with the Study Tool of Study Smart With Chris.

PREMIUM summaries are quality controlled, selected summaries prepared for you to help you achieve your study goals faster!

Summary - Artikelen experimental immunology

  • 1 Cancer-related inflammation

  • What are the 7 effects of inflammation on tumor?

    - Aids proliferation

    - Aids survival malignant cells

    - Promotes angiogenisis

    - Promotes metastasis

    - Subverts (ondermijnt) adaptive immune responses

    - Alters responses to hormones

    - Alters responses to chemotherapeutic agents

  • What are the 2 orders in which inflammation and tumors occur?

    - Sometimes there is inflammation before a malignant change ocurs. Chronical inflammation can lead to cancer.

    - In other types of cancer, an oncogenic change induces an inflammatory microenvironment that

    promotes the development of tumours

  • What are the 6 examples of evidence of the link between inflammation and cancer?

    • Inflammatory diseases increase the risk of developing many types of cancer (including bladder, cervical, gastric, intestinal, oesophageal, ovarian, prostate and thyroid cancer).

    • Non-steroidal anti-inflammatory drugs reduce the risk of developing certain cancers (such as colon and breast cancer) and reduce the mortality caused by these cancers.

    • Signalling pathways involved in inflammation operate downstream of oncogenic mutations (such as mutations in the genes encoding RAS, MYC and RET).

    • Inflammatory cells, chemokines and cytokines are present in the microenvironment of all tumours in experimental animal models and humans from the earliest stages of development.

    • The targeting of inflammatory mediators (chemokines and cytokines, such as TNF-α and IL-1β), key transcription factors involved in inflammation (such as NF-κB and STAT3) or inflammatory cells decreases the incidence and spread of cancer.

    • Adoptive transfer of inflammatory cells or overexpression of inflammatory cytokines promotes the development of tumours. 

  • What is the percentage of deaths by underlying infections and inflammatory responses, to all deaths from cancer worldwide?

    Epidemiological studies have shown that chronic inflammation predisposes individuals to various types of cancer. It is estimated that underlying infections and inflammatory responses are linked to 15–20% of all deaths from cancer worldwide

  • Name 3 triggers of chronic inflammation that increase the risk of  developing cancer, with an example

    - microbial infections (infection with Helicobacter pylori is associated with gastric cancer and gastric mucosal lymphoma)

    - autoimmune diseases (inflammatory bowel disease is associated with colon cancer)

    - inflammatory conditions of unknown origin (prostatitis is associated with prostate cancer

  • What does (also) indicate that cancer and inflammation are linked?

    treatment with non-steroidal anti-inflammatory agents decreases the incidence of several tumour types, and the mortality that results from several tumour types

  • What are the 4  hallmarks of cancer-related inflammation?

    - the presence of inflammatory cells and inflammatory mediators (chemokines, cytokines and prostaglandins) in tumour tissues

    - tissue remodelling similar to that seen in chronic inflammatory responses

    - angiogenesis  similar to that seen in chronic inflammatory responses

    - tissue repai

  • Name the 2 pathways in the connection between inflammation and cancer 

     

    - intrinsic pathway, driven by genetic alternations that cause inflammation and neoplasia (oncogenes)

    - extrinsic pathway, driven by inflammatory conditions that increase cancer risk (inflammatory bowel disease)

  • Decribe the intrinsic and extrinsic pathways

    plaatje.

    Cancer and inflammation are connected by two pathways: the intrinsic pathway and the extrinsic pathway. The intrinsic pathway is activated by genetic events that cause neoplasia. These events include the activation of various types of oncogene by mutation, chromosomal rearrangement or amplification, and the inactivation of tumour-suppressor genes. Cells that are transformed in this manner produce inflammatory mediators, thereby generating an inflammatory microenvironment in tumours for which there is no underlying inflammatory condition (for example, breast tumours). By contrast, in the extrinsic pathway, inflammatory or infectious conditions augment the risk of developing cancer at certain anatomical sites (for example, the colon, prostate and pancreas). The two pathways converge, resulting in the activation of transcription factors, mainly nuclear factor-κB (NF-κB), signal transducer and activator of transcription 3 (STAT3) and hypoxia-inducible factor 1α (HIF1α), in tumour cells. These transcription factors coordinate the production of inflammatory mediators, including cytokines and chemokines, as well as the production of cyclooxygenase 2 (COX2) (which, in turn, results in the production of prostaglandins). These factors recruit and activate various leukocytes, most notably cells of the myelomonocytic lineage. The cytokines activate the same key transcription factors in inflammatory cells, stromal cells and tumour cells, resulting in more inflammatory mediators being produced and a cancer-related inflammatory microenvironment being generated. Smouldering cancer-related inflammation has many tumour-promoting effects.

  • How was the intrinsic pathway discovered?

    when addressing why inflammatory cells and mediators are present in the microenvironment of most, if not all, tumours and therefore are present in cases for which there is no .epidemiological basis for inflammation

  • 2 Dynamic imaging of the immune system: progress, pitfalls and promise

  • What is the main advantage of multi-photon microscopy for immunologists?

    it gives them the ability to image deep into live tissues, a capacity that depends greatly on the choice of laser system, the scanhead and the many optical components.

  • What can you say about the lasers of  two-photon imaging?

     

    • Computer-tuned Ti:Sapphire system with integrated solid-state pump laser producing output ranging from ~700–1080 nm.

    • 600–800 mW of average power at 780nm; preferably 1.5 W of peak power to allow useful output at long or short wavelengths, such as those used for enhanced yellow fluorescent protein (915 nm) or indo-1 (705 nm).

    • Integrated into a system that limits pulse broadening and peak power loss owing to dispersive elements such as glass lenses. ‘Prechirping’ the laser using adjustable diffraction gratings or prisms that retard the ‘red’ components of the beam relative to the ‘blue’ components can offset such dispersion.

  • What can you say about the detectors of  two-photon imaging?

    • Usually a photomultiplier tube used without a pinhole for two-photon imaging because fluorescence radiates from a diffraction-limited focal volume and even scattered photons can contribute to a useful signal.

    • Ideal detector placement is as close as possible to the back aperture of the objective; common in custom-built systems, but generally impractical on commercial systems that double as confocal microscopes.

  • What can you say about the Acquisition speed of  two-photon imaging?

    • Laser scanners operating in either a raster or resonate mode.

    • Linear raster scanning is precise but only able to generate images at a few frames per second.

    • Resonant scanning is high-speed, generating 30 or more frames per second, thereby allowing real-time specimen examination and frame averaging to reduce noise.

  • What can you say about the Objectives of  two-photon imaging?

    • Should have high infrared transmission and a large numerical aperture (NA). High NA water-dipping objectives (NA = 0.8–0.95) are preferred because they do not require the use of a cover glass, typically have long working distances and enhance fluorescence signal collection owing to their wide field of view.

    • Need to optimize the diameter of the laser beam entering the back aperture of the lens. A good compromise for maintaining both laser power and high spatial resolution is to slightly underfill (~70%) the back aperture

  • What is Confocal microscopy? 

    A form of fluorescence microscopy in which out-offocus signals are rejected by an aperture that restricts all light from reaching the detector except that originating from the focal plane of the excitation spot.

  • What is Two-photon microscopy?

    A fluorescence-imaging technique that takes advantage of the fact that fluorescent molecules can absorb two photons nearly simultaneously during excitation before they emit light. This technique allows all emitted photons to contribute to a useful image.

  • What is Positron emission tomography?

    An imaging method that depends on the threedimensional detection of (positrons) radiation from a probe that is typically localized to a cell by direct ex vivo labelling or in situ metabolic conversion of a precursor compound.

  • What is Magnetic resonance imaging?

    A method that uses detection of changes in the alignment of protons in a strong magnetic field when they are perturbed by radio wave pulses to generate structural information about an object in that magnetic field.

  • Name 3 advantages of single-photon imaging over two photon imaging.

    • Shorter wavelength and higher resolution

    • Less expensive and easier to maintain lasers

    • Better performance in some tissues (such as the skin and liver)

  • Name 3 advantages of two photon imaging over single photon imaging.

    • Greater penetration

    • Longer wavelength, confined excitation and all emission detected

    • No bleaching of out-of-focus planes

  • Name 4 limitations of single-photon imaging over two photon imaging.

    • Limited depth of penetration in scattering tissues

    • Bleaching in all planes

    • Phototoxicity

    • Chromo- and fluorophore-based phototoxicity

  • Name 4 limitations of two photon imaging over single photon imaging.

    • Longer wavelength and lower resolution

    • Nonlinear phototoxicity, linear heating and adsorption in dark tissues

    • Reflections in some tissues

    • Chromo- and fluorophore-based phototoxicity

  • Which 10 tissues have been imaged? 

     

    Lymph nodes,

    Thymus,

    Liver,

    Central nervous system,

    Bone marrow,

    Skin,

    Spleen,

    Gut,

    Eye,

    Kidney

  • Under what conditions, and with what comments has the Lymph nodes been imaged?

     

    Conditions: Explant and intravital

    Comments:

    • Intravital imaging of inguinal and popliteal lymph nodes

    • Any lymph nodes as an explant, including pancreatic

    • Oxygen level and perfusion important if explant is submerged

  • Under what conditions, and with what comments has the Thymus been imaged?

    condition: explant,

    comment• Intravital imaging not yet possible

  • Under what conditions, and with what comments has the Liver been imaged?

    Condition: Intravital one-photon (confocal) imaging

    Comment: • Easily damaged by surgery • Use propidium iodide to detect dead cells

  • Under what conditions, and with what comments has the Central nervous system been imaged?

    Explant and intravital • Spinal cord immobilized by stereotactic system

  • Under what conditions, and with what comments has the bone marrow been imaged?

    Intravital • Two-photon imaging through parietal bone

  • Under what conditions, and with what comments has the skin been imaged?

    Explant and intravital • One-photon imaging is better than twophoton imaging for Langerhans cells

  • Under what conditions, and with what comments has the spleen been imaged?

    Explant and intravital • Both one-photon and two-photon imaging is useful

    • Red pulp contains many T cells

  • Under what conditions, and with what comments has the gut been imaged?

    Explant, intravital and using fibre-optic microscopy • Low autofluorescence • Transepithelial processes of dendritic cells

  • Under what conditions, and with what comments has the eye been imaged?

    One-photon imaging using fibre-optic microscopy • Cornea functions as a transparent window so no surgery is required for imaging • Some motion artefacts

  • Under what conditions, and with what comments has the kidney been imaged?

    Intravital one-photon and two-photon imaging • Limited view of distal collecting system

  • What is Luminescence imaging?

    A technique that uses photons emitted by the process of luminescence, rather than fluorescence, to obtain an image of cells in a living animal. This method is extremely sensitive and non-invasive but generates data of much lower resolution than microscopebased fluorescent imaging.

  • What is Knock-in technology?

    The introduction of a transgene into a precise location in the genome, rather than a random integration site.  knocking-in uses the same technique of homologous recombination as a knockout strategy but the targeting vector is designed to allow expression of the introduced transgene under control of the regulatory elements of the targeted  gene.

  • What is BAC transgenic technology?

    A method for creating genetically altered mice in which very large segments of mouse genomic DNA are propagated in bacteria and used to achieve physiological patterns of gene expression. This technique avoids the need to create knock-in mice by homologous recombination in embryonic stem cells.

  • What is SIN vectors?

    Retroviral or lentiviral vectors that contain mutations that inactivate the enhancer element in the 3′ LTR (long terminal repeat). Because the sequence of the 3′ LTR is used to reconstitute the 5′ LTR during reverse transcription, these vectors ‘self-inactivate’ the 5′ LTR enhancer before integration into the host-cell DNA. This allows exogenous gene regulatory sequences downstream of the 5′ LTR to control gene expression after integration.

  • What is Emission spectrum?

     

    A quantitative representation of the wavelengths (energies) of the photons emitted from a fluorescent compound  after it is excited by shorter wavelength (more energetic) photons from an illumination source.

  • What is Excitation optimum?

    The wavelength of incident light that is best absorbed by and causes maximal emission from a fluorescent compound.

  • Technologies for the future

    - More colours

    - Going deeper

    - Imaging faint molecular events

    - Breaking the resolution limit

    - Breaking the speed limit

     

  • Explain More colours for Technologies for the future

    • Use multibeam devices, such as a prototype dual-beam, four-detector multi-photon microscope that rapidly alternates between two laser lines, to allow up to eight fluorescent probes to be imaged with only a small loss in temporal resolution.

  • Explain Going deeper for Technologies for the future

    • Cut the tissue to expose deeper regions, for example, using vibratome thick sectioning as applied to the thymus to look at Ca2+ signalling and to lymph nodes to examine T-cell movement. The main problem is tissue damage.

    • Amplify laser output. Regenerative amplifiers allow excitation 1 mm into a tissue. Drawbacks include a decrease in

    effective scan rate and increased thermal damage.

    • Increase detector sensitivity. Gallium arsenide phosphide detectors promise a 2–4 fold increase in sensitivity, possibly allowing visualization of low abundance fluorescent protein chimaeras such as those used to study protein

    re-organization in the immunological synapse.

    • Use needle-like gradient index lenses90, often in combination with fibre-optic microscopy.

    • Harmonic generation microscopy95 can be used with less tissue damage, allowing more laser power to be used.

  • Explain Imaging faint molecular events for Technologies for the future

    • Tissue autofluorescence (such as that from flavoproteins and aromatic co-enzymes) limits detection of faint signals by decreasing the signal–noise ratio.

    • This autofluorescence problem can be overcome by exploiting the lifetime of the excited state. For example, quantum dots have a longer lifetime than organic dyes, with most emission taking place after autofluorescence emission but before phosphorescence emission98. A two-photon microscope able to perform fluorescence lifetime imaging over the nanosecond to microsecond timescale could distinguish these events and also perform in situ oxygen measurements.

  • Explain  Breaking the resolution limit for Technologies for the future

    • Resolving power is based on the wavelength of the illumination beam and is ~200 nm for blue light and proportionally poorer for the infrared light used in two-photon microscopy.

    • Frequency domain information from structured saturating illumination generated by intersecting laser beams can extend the limit to less than 10 nm for light microscopy100, but the time resolution of this approach is limited and it results in greatly increased photobleaching101. It is also currently unable to provide three-dimensional information.

    • Multi-photon Raman spectroscopy102 might extend imaging to the molecular level.

  • Explain Breaking the speed limit for Technologies for the future

    • Spinning disc confocal systems offer high speed imaging at more than 100 frames per second, but they typically operate in single-photon mode with limited imaging depth.

    • A reflector-based system provides multiple beamlets compatible with two-photon excitation, increasing imaging speed beyond that of resonant scanners103. However, this technology requires use of a camera with images that are degraded by the scattering of emitted photons, limiting the effective depth of imaging.

  • Name the 7 advantages of Explants to intravital imaging 

     

    • Higher throughput

    • Relatively free of movement artefacts

    • Defined environment

    • Access to different surfaces of tissue

    • Pharmacological studies

    • Acute cell addition

    • Imaging human biopsies possible

  • Name the 4 advantages of intravital imaging to explants

    • True in vivo observations

    • Physiological oxygen levels and metabolism

    • Vascular and lymphatics intact

    • Neural innervation

  • Name the 3 limitations of explants to intravital imaging

     

    • Vascular and lymphatics present but no flow

    • Lack neural innervation

    • Processes stop during death and are restarted by oxygenation and/ or perfusion

  • Name the 5 limitations of intravital imaging to explants

    • Lower throughput

    • Motion artefacts from breathing and blood flow

    • Anesthaesia effects

    • Surgical trauma

    • Access of inflammatory cells might cause progressive damage

     

Read the full summary
This summary. +380.000 other summaries. A unique study tool. A rehearsal system for this summary. Studycoaching with videos.

Latest added flashcards

Decribe the intrinsic and extrinsic pathways

plaatje.

Cancer and inflammation are connected by two pathways: the intrinsic pathway and the extrinsic pathway. The intrinsic pathway is activated by genetic events that cause neoplasia. These events include the activation of various types of oncogene by mutation, chromosomal rearrangement or amplification, and the inactivation of tumour-suppressor genes. Cells that are transformed in this manner produce inflammatory mediators, thereby generating an inflammatory microenvironment in tumours for which there is no underlying inflammatory condition (for example, breast tumours). By contrast, in the extrinsic pathway, inflammatory or infectious conditions augment the risk of developing cancer at certain anatomical sites (for example, the colon, prostate and pancreas). The two pathways converge, resulting in the activation of transcription factors, mainly nuclear factor-κB (NF-κB), signal transducer and activator of transcription 3 (STAT3) and hypoxia-inducible factor 1α (HIF1α), in tumour cells. These transcription factors coordinate the production of inflammatory mediators, including cytokines and chemokines, as well as the production of cyclooxygenase 2 (COX2) (which, in turn, results in the production of prostaglandins). These factors recruit and activate various leukocytes, most notably cells of the myelomonocytic lineage. The cytokines activate the same key transcription factors in inflammatory cells, stromal cells and tumour cells, resulting in more inflammatory mediators being produced and a cancer-related inflammatory microenvironment being generated. Smouldering cancer-related inflammation has many tumour-promoting effects.

What is the role of the innate immunesystem?

Eradication of the pathogen
Alerting the adaptive immune system

Pattern recognitions recognize PAMPs. What are these PAMPs and give two examples. (Give a more detailed answer than ‘viruses and bacteria’).

PAMPs are small molecular sequences consistently found on pathogens that are recognized by Toll-like receptors (TLRs) and other pattern recognition receptors (PRRs). PAMPs include bacterial lipopolysaccharide "endotoxin" (LPS→TLR4), bacterial flagellin, lipoteichoic acid, lipoproteins and peptidoglycan (→TLR1,-2,-6), mannose residues, N-formylmethionine, fungal glucans, endogenous heat shock proteins, extracellular matrix molecules, and nucleic acid variants associated with viruses (vRNA→TLR3, unmethylated cytosin-guanosin dinucleotide (CpG islands)→TLR9, dsRNA) and bacteria (bacterial DNA, unmethylated cytosin-guanosin dinucleotide (CpG)→TLR9).

Name 4 types of pattern recognition receptors:

- C-type lectin receptors
- Toll-like receptors
- NOD-like receptors
- Retinoic acid-inducable gene (RIG)-I-like receptors

What is the difference between plasma and serum?

Both plasma and serum are derivatives of blood. Both contain electrolytes, other proteins, drugs, hormones and toxins. Both can be acquired from centrifugation and purity depends on the duration and the frequency of this process. Both can be used for diagnostic and therapeutic purposes. But plasma is serum with fibrinogen and clotting factors. So plasma tends to discolor on standing, whereas serum does not. Separation of plasma is relatively easy and inexpensive, whereas separation of serum requires higher levels of expertise and expenses. Plasma is most commonly used for therapeutic purposes where, either the full plasma (Fresh frozen plasma), clotting factor removed (Cryo poor plasma) or the clotting factors itself (Cryo precipitate) can be used. Serum is most commonly used for diagnostic purposes. Animal sera are used in humans for therapeutic purposes.
Plasma can be considered as the crude product of precipitation of blood whereas serum is the refined plasma minus the fibrinogen and the other clotting factors.

What is plasma, and what does it contain?

Blood plasma is the straw-colored/pale-yellow liquid component of blood that normally holds the blood cells in whole blood in suspension. It makes up about 55% of total blood volume.[1] It is the intravascular fluid part of extracellular fluid (all body fluid outside of cells). It is mostly water (92% by volume), and contains dissolved proteins (i.e.—albumins, globulins, and fibrinogen),[2] glucose, clotting factors, electrolytes (Na+, Ca2+, Mg2+, HCO3- Cl- etc.), hormones and carbon dioxide (plasma being the main medium for excretory product transportation). Plasma also serves as the protein reserve of the human body. It plays a vital role in an intravascular osmotic effect that keeps electrolytes in balanced form and protects the body from infection and other blood disorders.[3]

What is serum, and what does it contain?

In blood, the serum is the component that is neither a blood cell (serum does not contain white or red blood cells) nor a clotting factor; it is the blood plasma with the fibrinogens removed. Serum includes all proteins not used in blood clotting (coagulation) and all the electrolytes, antibodies, antigens, hormones, and any exogenous substances (e.g., drugs and microorganisms).

How do you calculate sensitivity?

sensitivity = number of true positives / (number of true positives + false negatives) = probability of a positive test ginven the patient is ill

sensitivity = number of true positives / total number of sick individuals in the population

How do you calculate specificity?

specificity = number of true negatives / (number of true negatives + false positives) = probability of a negative test given that the person is well.
specificity = number of true negatives / total number of well people in the population

What does IL-23 do with the generation of proinflammatory  and regulatory T cells?

 IL-23 drives the generation of proinflammatory T cells

 IL-23 inhibits the generation of regulatory T cells