DBMB 712: Immunology Week 1

What is immunity?

state of protection against foreign pathogens or substances (antigens)

What is the first example of the first concept of immunity?

Thucydides 430 BC

What are some examples of when vaccinations worked?

smallpox

What is variolation?

take a pustle of someone who had the disease and scratched into the skin (early vacination)

What did Edward Jenner do for smallpox?

He used material from cowpox lesions to protect people against smallpox

What is attenuation?

When you use a weakened or aged culture that has lost its virulence to allow the body to mount a resistance but you do not get sick from it.

Who played with chickens and realized that if you used an attenuated culture then the subject didn't die?

Pasteur

When was the first human vaccination and on who?

1885 on Joseph Meister

Who made the rabies vaccination?

Pasteur

What is innate immunity?

"anatomic, physical barriers"

- mucous,

- tears,

- skin,

- cilia

- membranes

- chemicals (acid, enzymes)

- inflammation/fever

- phagocytosis

What immune cells are used in innate immunity?

Phagocytes and Natural Killer cells

What is aquired immunity?

"Physiologic and cellular barriers"

- T cells and B cells

- antibodies

- memory part of immune system

What are the defense chemicals in oral secretions?

1. Calprotectin

2. Defensins

3. Cathelicidins

4. Saliva

5. Lysozyme

6. Peroxidase

7. Histatins/Cistains

8. SLPI, PRP

9. Mucins

What is calprotectin?

starves microbes

What are defensins?

membrane pore forming peptide

What are Cathelicidins?

lysosomal antimicrobial polypeptide

What is in saliva that is used for the innate immune system?

Ig, lysozyme, lactoferrin, periodases

What is lysozyme?

aggregates microbes and amphipathic sequences

What is peroxidase?

oxidizes bacterial enzymes in glycolytic pathway

What are mucins?

aggregates bacteria, various effects

What is GCFs?

GCF: Gingival crevicular fluid

- Found in the sulcus under the gingiva (different than saliva) and is full of Igs, and other enzymes for protection

What immune cells use phagocytosis?

neutrophils, monocytes, and macrophages

What are pathogen associated molecular patterns (PAMPs)?

conserved patterns on the cells that the immune system can recognize as NOT our own (bacteria or pathogens)

What are some examples of PAMPs?

LPS, bacterial DNA, double-stranded RNA (viruses), glucans (cell wall of fungi) , flagellin

How do we recognize PAMPs?

with pattern recognition receptors (toll like receptors)

What are natural killer cells

nonphagocytic lymphocytes that kill virus infected cells, if it does not have MHC1 it kills the cell

What are the two receptors on a NK cell? How does it know when to kill a pathogen?

1. Antigen receptor

2. MHC I receptor

- If a cell does not express MHC1, the NK will kill the cell

What are acute phase proteins? What organ produces it?

serum proteins that are produced in the liver in response to tissue-damaging infections and other inflammatory stimuli

What is a C reactive protein?

acute phase protein that binds to bacteria to promote phagocytosis and activates the complement system

How does acute phase proteins work?

activates classical complement system resulting in increased clearance from a pathogen

What is the complement system?

has at least 30 components which interact in an ordered and tightly regulated manner to cause phagocytosis of target cells

What does opsonin do?

promote phagocytosis

What are the three important outcomes of activation?

1. Inflammation: anaphylatoxins promote the inflammation

2. Lysis: Membrane Attack complexes punches holes in membrane

3. Opsonin: enchange phagocytosis

What are the two lines of hematopoietic stem cells (HSC)?

myeloid line and lymphoid line

What are some characteristics of hematopoietic stem cells?

pluripotent and self-renewing

Cells from which HSC lineage are the first responders to infection?

myeloid

Cells from which HSC lineage lead to T and B cells?

lymphoid

What are the four main types of myeloid-erythroid progenitors?

granulocytes, macrophages, red blood cells, megakaryocytes (form platelets)

What are the the types of granulocytes?

neutrophils, eosinophils, basophils

What is the main circulating WBC, highly phagocytic, and usually first responder to infection?

Neutrophil

What is NETosis?

neutrophil exocytosis trap (traps microbes) that causes cell dealth without phagocytosis

What is the least abundant WBC that is a nonphagocytic cell involved with antiparasite defense and allergies?

basophil

What is similar to basophils but not found in blood only tissues, nonphagocytic?

mast cells

What cell is involved in parasitic infections and allergies, they have both phagocytic and extracellular killing?

eosinophil

What are some non granulocyte cells?

monocytes, macrophages, and dendritic cells

What do monocytes differentiate into?

Macrophages

What is the difference between primary and secondary lymphoid organs?

primary is where immune cells develop and secondary is where it is initiated

What are the primary lymphoid organs?

thymus (trains T cells) and bone marrow

What are the cells that come from the bone marrow?

hematopotetic stem cells, B lymphocytes develop and mature, develop T lymphocytes

How do T cells mature in the thymus?

has a microenviorment of thymic cortex and medulla, teaches cells affinity of binding with MHC-peptidesand removes the cells that react too strongly to own body cells

What are thymocytes?

immature T cells

What are secondary lymphoid organs?

lymph nodes, spleen, mucosa-associated lymphoid tissue(MALT), other diffuse and loosely orgnaized area

What is mucosa-associated lymphoid tissue (MALT)?

- important layer of defense against infection at mucosal and epithelial layers,

- organizes responses to antigens that enter mucosal tissues,

- include follicles and lymphoid microenvironments

T/F. B cells need MHC to recognize a cell

F

T/F. T cells need MHC to recognize a cell

T

What does every cell in the body but RBC (all nucleated cells) have on its surface?

MHC 1

What is the difference between MHC class 1 and MHC class II?

1 is smaller and has 1 tranmembrane segment, class II has 4 proteins and two transmembrane segments

A CD8 is a ___ T cell

cytotoxic

A CD4 is a ___ T cell.

helper

What is the difference between a T cell and a B cell receptor?

B cell has two antigen binding sites and T only has one

What are the three regions of the B cell and T cell receptors?

variable, constant, and transmembrane regions

What are the different types of hypersensitivity?

1. immediate (igE, classic allergies)

2. antibody (activation of complement)

3. immune complex

4. cell-mediated (delayed hypersensitivity)