Blood and antibodies

Fox Chapter 15 (immune system)
also part of Chap 13 (for blood)
A figure from Chapter 20

Fig. 13.1

Overview of blood cell types

plasma and hematocrit (formed elements), Buffy coat between

I. Plasma - (serum lacks fibrinogen) fluids, nutrients, O2, CO2, ions
proteins (synthesized in liver except gamma globulins)(clotting)
Albumins
Globulins
Fibrinogen

II. Hematocrit
Erythrocytes 5-6 million/ml
Leucocytes 5-10 thousand/ml
Platelets 250,000-400,000/ml formed from megacaryocytes
(antibodies) ions, wastes, hormones

Blood clotting

Fig. 13.9
Platelets 250,000/ml from megacaryocytes
Clotting Platelet adhesion then fibrin (from fibrinogen)
Cascades
activated Hageman factor
prothrombin -> thrombin
fibrinogen ->fibrin
Hemophelia is famous disorder

Hemophelia (4 SLIDES)
pedigree
Victoria, Nicholas II & Alexandra - Alexis, Rasputin
on X
problem with AIDS for clotting factor

Erythrocytes

Fig. 13.3
Red blood cells (corpuscles) (erythrocytes)
no nuclei
O2 transport, hemoglobin, anemia
last 120 days, made in marrow, recycled
iron recycling in liver is what makes feces dark (and skin yellow in jaundice [hepatitis]) - bile pigments

Polymorphonuclear granulocytes

There are non-specific responses to injury

White blood cells (leucocytes as in leukemia)
Polymorphonuclear granulocytes (phagocytosis, etc)
neutrophil (60-70%) phagocytosis
here is a picture from our histology course of a neurtophil showing the complex nucleus

Fig. 15.2
chemotaxis after 30-60 min
more synthesized especially in bacterial infection
reset thermostat (pyrogens)
eosinophil (1.5%) phagocytosis
allergic and parasitic inflamation
basophil (0.1%) histamine containing
like mast cells

Phagocytosis and review slides

Fig. 15.1
Phagocytosis (cell eating), fusion of primary lysosome, formation of secondary lysosome

SLIDES: blood cells (SEM= scanning electron micrograph))
white blood cell engulfing bacterium (Light Micrograph)
same (SEM)
SLIDES macrophage eating E. coli
macrophage - asbestos
fibrin (2 slides)

Monocytes

Fig. 15.6
Mononuclear cells
monocytes (5%) (as in mononucleosis) (phagocytosis)
late chemotaxis become macrophages
alveolar macrophages in lungs
Kupffer's cells in liver

Inflammation

Fig. 15.5
Inflammation and phagocytosis
Triad redness, warmth, swelling
Histamine (from mast cells, platelets)

lymphocytes:

There are specific responses involving antibodies and other mechanisms

T-cells (80%) (thymus - near heart) cell
(transplant) cytotoxic, suppressor, helper (AIDS)
B-cells (20%) (bone marrow, actually bursa of Fabricius) (become plasma cells)
antibodies

Blood groups

Fig. 13.5
Blood groups
This topic is fundamental and a bit confusing.
genotypes IA IA or IA i have phenotype A, A antigens, anti-B antibodies
genotypes IB IB or IB i have phenotype B, B antigens, anti-A antibodies
genotype IA IB has phenotype AB, A and B antigens, no antibodies
genotype ii has phenotype O, no antigens, antibodies to both A and B
O universal donor, AB universal recipient
There are already antibodies since blood group polysaccharides are like those of bacteria even though there was no previous exposure to antigens. IgM not cross placenta

Rh factor

- mother and + fetus problem if blood crosses over (during delivery)
problem is next time since IgG crosses placenta
treat mother with antibodies (passive immunity) then she will not mount active immunity

Active and passive immunity

When I was a kid, nearly everrybody got measles, mumps, and chicken pox. We were presumably immune for life (active immunity). When we had the disease was part of out health record.

Vaccines - active immunity (like disease)
memory cells of immune system
Edward Jenner 1796 "encowment"
Farmers were less likely to get smallpox because they got a related disease, cowpox
When I was a kid, you could not enroll in school without the scar
Smallpox is so completely eliminated that one issue is whether to get rid of lab virus.

When I was a kid, there was (still) a polio epidemic.
A kid at a birthday party I went to got polio, so I went to the family doctor for gamma globulin, passive immunity
(1954 Salk vaccine injected, soon Sabin vaccine in sugar cube)

Fig. 15.15
lymph system and nodes

Antibodies

Humoral immunity - B cells

Fig. 15.23
clones of plasma cells and memory cells derived from B cells for specific antigens

Fig. 15.7
Another version of this figure

Fig. 13.4
(showing only erythrocytes)
Interesting continued development through life of monocytes, granulocytes and lymphocytes from stem cells
note, the bone marrow which makes blood cells is mostly in the head and ribs, the two most likely locations for X-rays which are dangerous

Fig. 15.8
Antigen (virus or bacterial coat, usually not self)
Antigenic determinant (epitope 5-15 anino acids)
IgD on B cells, antigen receptors

Fig. 15.10
Antibody
2 long chains and 2 short chains, variable region at the end of all 4 makes it specific for antigen
An amazing mechanism where the gene is rearranged accounts for diversity.
IgG most abundant, monomer, cross placenta

Fig. 20.55
Antibodies cross placenta, also in mother's milk, and late weaning covers until child's own antibodies are formed.

Fig. 15.26
IgE allergy, bind to mast cells (histamine)

T-cells

Fig. 15.17
helper T cells express CD4
antigen presenting macrophage
MHC major histocompatability complex 20 genes 50 alleles each
Class II MHC only on macrophages (and B lymphocytes)
antigen presented by to B cell

Fig. 15.18
cytotoxic (killer) T cells express CD8
Class I MHC - actually on lots of cells (including the infected cellsshown here)
[try to match MHC (tissue typing) for transplantation]

Fig. 15.19
Interleukin-2 is released by helper T cells to cause killer and helper cells to proliferate

Exam questions from 2004 - 2007 related to this lecture

What kind of cell becomes a macrophage?

monocyte

Presence of what in type O people would lead to agglutination if there were a transfusion with any other type of blood?

anit-A and anti-B antibodies

Presence of what in type O people would lead to agglutination if there were a transfusion with any other type of blood?

anit-A and anti-B antibodies

Eosinophils are a type of polymorphonuclear granulocyte. What is eosin?

a histological stain

What kind of molecule is IgG? (Be more specific than "protein.")

antibody

In a neutrophil or macrophage, after phagocytosis of a bacterium, what cellular organelle full of enzymes fuses with the phagosome to destroy the bacterium?

lysosome

A B lymphocyte develops into what protein-producing cell?

plasma

When it is needed, what important protein does a plasma cell export?

antibody

What cell is specifically depleted in AIDS?

Helper T

The first vaccination was for what disease?

small pox

What are the two types of lymphocytes?

B&T

For Rh, a second exposure is very serious. Why is a first exposure, like a transfusion of the wrong blood group, bad in ABO blood groups?

there are already antibodies

A bacterium is engulfed into a vacuole in a phagocytic white blood cell. What cellular organelle, a bag of acid hydrolases, fuses with this endosome to destroy the bacterium.

lysosome

Like neutrophils, monocytes infiltrate the injury site, attracted by chemotaxis. What is the difference in timing?

monocytes are later

Considering how much fibrin is around when clotting is needed, how come fibrin does not make blood clot all the time?

unless cleaved by clotting cascade, fibrinogen is inactive

Macrophages are derived from what type of white blood cell?

monocytes

Why are the prospects for worldwide elimination of flu by immunization more elusive than for smallpox or polio?

evolution of virus in alternative hosts like birds and pigs

Antibodies produced by plasma cells are ineffective against infected cells. What specific type of lymphocyte destroys such cells loaded with foreign bacteria or viruses?

killer (cytotoxic) T lymphocytes

Class 1 & 2 MHC (major histocompatibility complex) molecules are expressed on the surfaces of various cells. Why is it almost guaranteed that yours are different from mine?

many genes, many alleles of each

If type A red blood cells are transfused into a type B person, antibodies in the type B blood will cause the red blood cells to clump. What is this clumping called?

agglutination

What is the chemical signal that the helper T cell uses to cause the appropriate type of killer T cells to proliferate?

interleukin 2

Which specific antibody crosses the placenta to give the baby the mother's immunities early in life?

IgG

In what way is IgG different from IgM with regard to the placenta and blood groups?

IgG for Rh cross, IgM for ABO not cross

"Monocytes have a late chemotaxis and form macrophages." Translate.

these white blood cells are attracted to the site of injury after polymorphonuclear granulocytes and further develop into big phagocytic cells

Which specific type of white blood cell is depleted in AIDS (acquired immunodeficiency syndrome)?

CD4-expressing (helper)

Why are lysosomes an important part of phagocytic leukocytes?

they merge with endosomes to digest them

What kind of immunity does RhoGAM confer in the treatment for Rh- mothers?

passive

Why is there a major difference between small pox and flu (influenza) with respect to the prospects for total elimination of the disease from the worldwide human population?

flu evolves and has alternative animal hosts

What purpose does IgD on the surface of B cells serve?

it is the antigen receptor

An allergen binding to IgE on the surface of mast cells causes the release of what substance from its granules?

histamine

Class II MHC (major histocompatability complex) is expressed only on macrophages and B lymphocytes. What about class I?

all cells, involved in attack on infected cells

Why is AB the universal recipient?

no A or B antibodies

Neutrophils, eosinophils and basophils are all white blood cells. Name a different type of white blood cell.

monocytes, lymphocytes (B and T)

Why is there so much variability in the MHC (major histocompatability complex)?

20 genes, 50 alleles each

Why is it beneficial for the infant that IgG crosses the placenta and that IgA is in mother's milk?

passive immunity from mother

CD8 vs. CD4 coreceptors distinguish what types of cell?

Killer vs helper T cells

What is agglutination as it applies to antibodies and the blood groups?

antibody causes cells to clump

We don't worry so much about blood type (ABO) of the fetus vs the mother, but we do worry about Rh factor. Why the difference?

IgM does not cross placenta, IgG does

For what is IgE most relevant?

allergy

How can MHC be so variable?

20 genes 50 alleles each

If all goes as "intended," what happens to a bacteria-containing endosome in a white blood cell?

becomes secondary lysosome after merging with primary lysosome (etc.)

Which blood cells are the precursors of macrophages?

monocytes

Some bacteria come in through a small skin injury. How do phagocytitc cells get from an intact capillary to the site of the injury?

chem,otaxis, slither between endothlial cells

What is the major product exported from the B lymphocyte?

antibody molecules

What type of cells are the memory cells that can jump-start the response to the next exposure to an antigen?

B lymphocytes

What kind of protein is the antigen receptor on the surface of a B lymphocyte?

antibody (IgD)

What is the difference between an epitope and an antigen?

epitope (antigenic determinant) is the small portion of the antigen to which the antibody binds

How can an infant be immune to some diseases between birth and weaning?

IgG across placenta, IgA in milk



Return to Syllabus

Return to Stark Home Page

this page was last revised 8/5/08