(01) Intro to Immuno Flashcards
What is Blood Plasma?
The components of Blood after Red and White Cells have been removed
What are some materials found in blood plasma?
- Clotting Factors
- Antibodies
- Complement Proteins
What is Blood Serum?
Components of blood that are neither cells (red or white) or clotting factors.
- It is the clear-yellowish liquid that remains after clotting factors have been removed
What is a titer?
Measurement of the concentration of a substance in a solution.
- Typically refers to the conc. of antibodies specific for a particular Antigen
What does inflammation refer to?
- Body’s Response to injury (Redness, Swelling, or Pain)
What does the suffix -itis refer to?
- inflammation
What does the suffix -penia refer to?
- Deficiency, a lack (e.g. neutropenia: lack of neutrophils)
What does the suffix -cytosis refer to?
- Condition where there is an elevated number of white cells in the blood (e.g. leukocytosis)
What does the suffix -philia refer to?
- Elevated numbers of white cells in the blood, typically observed in infections
When does neutrophilia typically occur?
- During bacterial infections
When does eosinophilia typically occur?
- During Helminthic parasite or immediate-type hypersensitivity responses
What are bands (band forms)?
- Immature neutrophils that are observed in blood smears during bacterial infections
- During a serious bacterial infection, the body’s stores of neutrophils can be depleted, resulting in production of large numbers of new neutrophils in the BONE MARROW.
- Newly generated neutrophils in this case are released into the blood BEFORE they are MATURED - they have a characteristic appearance b/c the NUCLEUS is NOT yet SEGMENTED
What is lymphocytosis?
- Elevated Lymphocyte Counts
What is Granulocytosis?
- often used interchangeably with…
- Elevated granulocyte numbers
- Interchangeable with neutrophilia
T or F: the innate immune system involves both non-cellular and cellular innate immune responses.
True, together these prevent, clear, or control an infection
What is the general role of the innate immune system?
- Prevent or control infect while the ACUIRED immune response is being generated so the patient doesn’t suffer too much damage in the meantime
What is the general role of the acquired immune system?
- It CLEARS the infection with high specificity and efficiency
T or F: acquired immunity is the first system to respond when exposed to a new pathogen.
False, innate immune system responds first
Innate Immunity:
- Speed of Response
- Number of Specificities
- Response over course of infection
Speed:
- Moment of insult to 4-5days
Specificities:
- Limited and pretty much the with each infection. Only responsive to broad classes (LPS - in all gram - bacteria)
Response:
Constant (does not improve)
T or F: the innate immune response will be nearly the same each time a specific pathogen is encountered
True
Adaptive Immunity:
- Speed of Response
- Number of Specificities
- Response over course of infection
Speed:
- At least a week
Specificies:
- Highly variable, adapt to any product made by pathogen
Response:
- Improves over the course of the immune response
What is the major difference in adaptive immunity and innate immunity when it comes to second exposure?
Second Response
Innate:
- Same response
(same efficacy)
Acquired:
- Clonal Expansion
- Memory of Response
(more effective)
T or F: the acquired immune system is completely independent of the innate immune system (non of the effector mechanisms are dependent on the innate immune system)
FALSE, some of the acquired components are dependent on innate immune system
T or F: innate cells express highly specific receptors on their surface.
False, their receptors are more generalized
What type of receptors are found on innate cells and what do these receptors recognize?
Pattern Recognition Receptors (PRRs) that recognize Pathogen-Associated molecular patterns.
T or F: in the acquired immune system with B cells and T cells, receptors are specfic and recognize discreet structures of a pathogen
True
What are 3 non-cellular components of the innate immune system that are always present?
- Mechanical and Chemical Barriers
- Microbiological (normal flora)
- Complement Cascades
What are some examples of innate mechanical barriers to infection?
- Epithelial Cells joined by tight junctions
- Longitudinal Flow of air or Fluid
- Movement of mucus by cilia
What are some of innate chemical barriers to infection?
- Fatty Acids
- Lower pH
- Enzymes (e.g. pepsin)
- Antibacterial Peptides
- Salivary Enzymes
What are some innate microbiological barriers to infection?
- Normal Flora
Where are the proteins involved in the complement cascade found?
- how does the level of expression of these proteins change with infection?
- Serum and Extravascular Spaces
- Proteins are expressed at constitutive levels (no up regulation with infection)
What are the 3 end products that can result from complement cascades?
- Anaphylatoxins - inflammatory mediators
- Opsonins - permanently attached tags that mark pathogens for uptake and destruction by neutrophils and macrophages
- MAC (membrane attack complex) - structure that inserts into bacterial outer envolopes causing death of bacterium
What are the primary lymphoid tissues?
- Bone Marrow - all precursor immune cells generated here
2. Thymus - where Thyomcytes migrate and develope into T cells
What is the site where ALL acquired immune responses are initiated?
SECONDARY lymphoid tissue
- What cell type in the bone marrow gives rise to 3 types or progenitor cells?*
- Name these progenitor cell types.
Hematopoietic Stem Cells
- Common Erythroid Megakaryocyte progenitor
- Common Myeloid progenitor
- Common Lymphoid progenitor
What are the derivatives and subderivatives of the Common Erythroid/Megakaryocyte progenitor?
- Megakaryocytes
- –> Platelets - Erythroblast
- –> Erythrocyte (RBC)
What are the derivatives and subderivatives of the Common Myeloid progenitor?
- Common Granulocyte Precursor
- –> Neutrophil
- –> Eosinophil
- –> Basophil - Unknown Precursor
- –> Mast Cell
- –> Monocyte
a. Dendritic cells
b. Macrophages
What are the derivatives and subderivatives of the Common Lymphiod progenitor?
- NK/T cell precursor
- –> NK Cell
- –> T cell
a. Effector T Cell - B cell
- –> Plasma Cell
What cells are referred to by the general term “lymphocyte?”
B cells and T cells
T or F: NK cells are purely innate cells.
True
What are two main functions of Erythrocytes?
- O2 transport
2. Clearance of Immune Complexes from Circulation
What things are produced by Megakaryocytes?
- function?
Thrombocytes (platelets)
Function: Wound Repair
What types of cells are critical to INNATE immunity against bacterial and fungal pathogens?
Phagocytes
- Granulocytes (NEUTROPHILS)
- Macrophages
Granulocyte
- Type of Immunity
- Receptors
- Infection Type
- Abundance
- Shape
Immunity:
- Innate
Receptors:
- Pattern Recognition Receptors
Infection Type:
- Bacterial or Fungal (neutrophil)
- Parasitic (eosinophil)
Abundance:
- Most numerous in the body
Shape:
- Multi-Lobe Nucleus
What 3 cell types are collectively called granulocytes?
- WHAT CELL GIVES RISE TO THEM?
- how to differentiate?
Granulocytes - neutrophils, basophils, eosinophils
BAND CELLS = immature granulocytes
Differentiation:
- Look at the nucleus, band cells have one continuous nucleus where as granulocytes have lobes
What is a monocyte?
- Function?
- Precursor to a macrophage, found in circulation
- Do not have function until the leave vasculature, move into tissues and become macrophages
Macrophage
- Function(s)
- Receptor type
- immunity type
Functions
Innate:
-Recognize, engulf, and destroy potential pathogens that it recognizes with Pattern Recognition Receptors
Adaptive:
- Activate naive T cells
- Express antibody Fc Receptors
3 cell types involved in INNATE control of parasitic infections?
- Eosinophils
- Basophils
- Mast Cells
Eosinophils
- Primary Role
- Granule Contents
- Surface receptors
Primary Role:
- Control Parasitic Infections
Granule Contents:
- Inflammatory Mediators and Compounds toxic to parasites
Surface Receptors:
- IgE receptors
Basophils
- function
- un-defined, probably similar to eosinophils
T or F: Mast cells function purely in innate immunity.
True
What cells types function solely in innate immunity?
- Neutrophils
- Mast Cells
- NK Cells
- *Mast Cells
- Function
- Granule Contents
- Receptors
- Major Role in what response type?
Function:
- Protect against parasitic Pathogens
Granule Contents:
- Potents Inflammatory Mediators
Receptors:
- IgE antibody receptors
Major Role in..
- Immediate-Type hypersensitiviy responses like hay fever, asthma, and systemic anaphylaxis
Mastocytosis
- what is is?
- cause?
- change with age (2 types)?
Mastocytosis - Overabundance of mast cells that can be confined to the skin, selected organs, or systemic
Cause:
- Mutation in the c-kit gene
- Most Common Mutation: D816V (deletion in codon 816 or exon 17)
Age: Cutaneous Form (children) Systemic Form (adults)
What type of presentation should alert you to mastocytosis?
- Raised areas of the skin in a pattern that looks like it could have been the result of pressure applied to the skin
What type of innate cells work against viruses?
Natural Killer Cells (NK cells)
What innate cells work against:
- Bacteria and Fungi
- Parasites
- Viruses
Bacteria and Fungi:
- Neutrophils
- Macrophages
Parasites:
- Eosinophils
- Basophils
- Mast Cells
Viruses:
- NK cells
**Most of these cell types produce inflammatory Mediators
T or F: NK cells are considered lymphocytes
False, they have no antigen specific receptors
Describe how macrophages can cause inflammation.
- Macrophage detects bacterial pathogen via pattern recognition receptors (PRRs)
- Cytokines (inflammatory mediators) and Chemokines (chemotactic factors) are released
- Vasodilation and increased vascular permeability allows protein and fluid out of BV and into tissue
- Swelling, pain, and redness result from this
How is inflammation important to initiating the adaptive/acquired immune response?
- It promotes movement of antigens and antigen presenting cells into the nearest SECONDARY LYMPHOID tissues
***Remember ALL acquired immune responses are initiated within secondary lymphoid tissues
Name 6 important secondary lymph tissues.
- Adenoid
- Tonsil
- Lymph Node
- Appendix
- Spleen
- Peyer’s Patch in small intestine
What type of lymph tissue is the spleen?
- what does it do?
Spleen serves as a blood filter
- storage site for RBCs
- Removes old RBCs
What is the general function of red pulp in the spleen?
- white pulp?
Red Pulp:
- Storage site for new RBCs and Removal of old RBCs
White Pulp:
- Immune function with B cells and T cells
What are the zones of the white pulp in the spleen?
T Cells
- Periarteriolar Lymphoid Sheath (T cell zone)
- Perifollicular Zone (not imp.)
B Cells
- Marginal Zone
- B cell Corona
- Germinal Center*****
What does the T cell zone (periarteriolar sheath) surround?
- A central Arteriole
Describe the arrangement of the T cell zone, B cell zone, macrophages, and dendritic cells to each other and the purpose of this arrangement.
T cell Zone:
- Packed with T cells, and Professional Antigen Presenting Cells - Macrophages, and Dendritic cells
B Cell zone:
- Immediately adjacent to T Cell zone
- Allows contact between B Cells and effector T Cells in the T cell zone
T or F: In lymph nodes T cell and B cell zones are in close association
True
What is carried in lymph fluid?
- Carries antigens and antigen presenting cells from inflamed tissues into the lymph node via afferent lymphatic vessels
What zone in lymph nodes contains antigen presenting cells?
T cell zone
**same way as in the spleen
T or F: peyer’s patches are also organized very much like the spleen with a T cell zone adjacent to a B cell zone
True
What feature makes Peyer’s Patches unique from other secondary lymphoid tissue?
- what is the function of this?
- M Cells (microfold cells)
- Sample antigens are taken from the lumen of the gut and transported into Peyer’s patch for antigen presentation to T cells and sampling by B cell receptors
How do antigens get from Peyer’s patches to lymph nodes?
- Efferent Lymphatics present that transport antigens and antigen presenting cells (APCs) to lymph nodes
What is: MALT BALT GALT CALT NALT
**Note: BALT GALT, CALT and NALT are subsets of MALT
MALT: Mucosal Associated Lymphoid Tissue
BALT: Bronchus ALT
GALT: Gut ALT
CALT: Conjunctiva ALT
NALT: Nasal ALT
Where are most of the immune cells in the body located?
- 50% of the immune cells in the body are distributed into mucosal tissues
What 3 immune cell types are important in presenting antigens to naive T cells?
- innate or adaptive?
Innate:
- Dendritic Cells (most efficient)
- Macrophages
Acquired:
- B cells
What is the 1st step to generating an acquired immune response?
Presentation of an antigen to naive T cells
What about the morphology of dentritic cells aids in their ability to be the most potent antigen presenting cells?
- Large surface area from the many arms sticking out allow them to interact with many naive T cells at the same time
T or F: dentritic cells phagocytize particles using Pattern Recognition Receptors (PRRs).
False, macrophages use PRRs to recognize general classes of pathogenic material so it can be phagocytized
3 main functions of macrophages
- Pattern Recognition Receptors (PRRs) allow it to recognize and destroy microorganisms.
- Presents antigents to T cells
- Complement and Fc receptors allow it to find and destroy opsonized microbes
If pathogens evade the innate immune system and establish an infection, then what is the new role of the innate immune system?
- It controls the infection until an acquired immune response can be generated
What are the two branches of acquired immunity?
- Humoral (antibody mediated)
- T cell mediated immunity
What are the two most important steps in the developement of lymphocytes?
- Generation of Antigen Specific Receptors
- Removal of Lymphocytes that express antigen-specific receptors that bind tightly to determinant of the host (or patient).
What is the job of B cells?
Produce and Secrete Antibodies
What are the jobs of T cells?
- Produce Signals that direct the action of other cells
2. Specific effectors of cell-killing
What are the 2 types of T cells and what is the function of each?
CD4+
- Modulate activity of other immune cell types through their production of Cytokines
CD8+
- Effector cells that recognize and kill infected host cells
Why are their two arms of the acquired immune response?
- which involves B cells and which involves T cells
- Pathogens live in extracellular spaces in the host
- Antibody-mediated (B cell) most effective response - Pathogens live intracellularly
- T cell-mediated most effect response
What is permitted by somatic recombination?
Allows generation of tremendous repertoire of antibody and T cell receptor specificities from a small amount of DNA
Difference between B-cell receptors and T-cell receptors?
B-cell receptor = antibody
- Binds anything (nucleic acid, lipid, carbohydrate, protein, etc.)
T cell receptor
- only recognize peptide antigens that are displayed on one of two type of host proteins (MHC molecules)
What are MHC (major histocompatibility complex) antigens?
Proteins that bind and display peptide antigens for T cell recognition
What is the difference between MHC class I and MHC class II antigens?
MHC Class I
- Found on all nucleated cells in the body
MHC Class II
- Found only on antigen presenting cells (APCs)
What is the job of CD8+ T cells?
Recognize and Kill infected host cells
What is the general layout of the MHC class I pathway?
- Virus Infects Cell
- Viral Proteins Synthesized in Cytoplasm
- Bound Peptides transported by MHC class I to cell surface
- Cytotoxic (CD8) T cell recognizes complex of viral peptide with MHC class I and Kills infected cell
What T cell type is restricted to the MHC class II pathway?
CD4 - helper T cells
What is the general layout of the MHC class II pathway?
- Cell-surface immunoglobulin of B cell binds bacteria
- cell engulfs and degrades them producing peptides - Bacterial Peptides bound by MHC class II in endocytic vesicles
- Bound peptides transported by MHC class II to the cell surface
- Helper T cell recognizes complex of peptide antigen with MHC class II and activates B cell
T or F: in addition to activating B cells, CD4 T cells activate macrophages that have been infected
True, macrophages become more bactericidal when activated by CD4 T cells
T or F: activation requirements are needed to prevent activation of host-specific immune responses that would result in autoimmune responses.
True
Why cell type serves as an Antibody Factory?
Plasma Cells - fully differentiated B cells
Besides Plasma cells, what can B cells differentiate into?
Memory Cells
What organelle is enlarged in Plasma Cells and why?
ER because it is an antibody factory and the ER is the secretory network of the cell
Are antibodies destructive to pathogens?
- explain***
NO, the serve as BRIDGES between the innate and acquired immune response. They activate innate immune cells to perform their effector function
Which T cell type releases mediators by helper T cells that recruit effector cells to inflammatory sites?
CD4 (helper) T cells
Why do most immune cells have such a large surface area?
Allows them to interact in a significant way with any host cell they encounter
T or F: phagocytes must be able to rearrange their cytoskeleton to perform their function
True
