Antibody and antigen WORLD OF MICROBIOLOGY AND IMMUNOLOGY28•
be compatible with a B donor or an O donor. Since O has no
antigens, it is considered to be the universal donor. Type AB is
the universal recipient because its antibodies can accept A, B,
AB, or O. One way of getting around the problem of blood
types in transfusion came about as a result of World War II.
The great need for blood transfusions led to the development
of blood plasma, blood in which the red and white cells are
removed. Without the red blood cells, blood could be quickly
administered to a wounded soldier without the delay of check-
ing for the blood antigen type.
Another antigenic blood condition can affect the life of
newborn babies. Rhesus disease (also called erythroblastosis
fetalis) is a blood disease caused by the incompatibility of Rh
factors between a fetus and a mother’s red blood cells. When
an Rh negative mother gives birth to an Rh positive baby, any
transfer of the baby’s blood to the mother will result in the pro-
duction of antibodies against Rh positive red blood cells. At
her next pregnancy the mother will then pass those antibodies
against Rh positive blood to the fetus. If this fetus is Rh posi-
tive, it will suffer from Rh disease. Tests for Rh blood factors
are routinely administered during pregnancy.
Western medicine’s interest in the practice of vaccina-
tion began in the eighteenth century. This practice probably
originated with the ancient Chinese and was adopted by
Turkish doctors. A British aristocrat, Lady Mary Wortley
Montagu (1689–1762), discovered a crude form of vaccina-
tion taking place in a lower-class section of the city of
Constantinople while she was traveling through Turkey. Shedescribed her experience in a letter to a friend. Children who
were injected with pus from a smallpoxvictim did not die
from the disease but built up immunity to it. Rejected in
England by most doctors who thought the practice was bar-
barous, smallpox vaccination was adopted by a few English
physicians of the period. They demonstrated a high rate of
effectiveness in smallpox prevention.
By the end of the eighteenth century, Edward Jenner
(1749–1823) improved the effectiveness of vaccination by
injecting a subject with cowpox, then later injecting the same
subject with smallpox. The experiment showed that immu-
nity against a disease could be achieved by using a vaccine
that did not contain the specific pathogen for the disease. In
the nineteenth century, Louis Pasteur(1822–1895) proposed
the germ theory of disease. He went on to develop a rabies
vaccine that was made from the spinal cords of rabid rabbits.
Through a series of injections starting from the weakest
strain of the disease, Pasteur was able, after 13 injections,
to prevent the death of a child who had been bitten by a
rabid dog.
There is now greater understanding of the principles of
vaccines and the immunizations they bring because of our
knowledge of the role played by antibodies and antigens
within the immune system. Vaccination provides active immu-
nity because our immune systems have had the time to recog-
nize the invading germ and then to begin production of
specific antibodies for the germ. The immune system can con-
tinue producing new antibodies whenever the body is attacked
again by the same organism or resistance can be bolstered by
booster shots of the vaccine.
For research purposes there were repeated efforts to
obtain a laboratory specimen of one single antibody in suffi-
cient quantities to further study the mechanisms and applica-
tions of antibody production. Success came in 1975 when
two British biologists, César Milstein(1927– ) and Georges
Kohler (1946– ) were able to clone immunoglobulin (Ig)
cells of a particular type that came from multiple myeloma
cells. Multiple myeloma is a rare form of cancer in which
white blood cells keep turning out a specific type of Ig anti-
body at the expense of others, thus making the individual
more susceptible to outside infection. By combining the
myeloma cell with any selected antibody-producing cell,
large numbers of specific monoclonal antibodies can be pro-
duced. Researchers have used other animals, such as mice, to
produce hybrid antibodies which increase the range of
known antibodies.
Monoclonal antibodies are used as drug delivery vehi-
cles in the treatment of specific diseases, and they also act as
catalytic agents for protein reactions in various sites of the
body. They are also used for diagnosis of different types of
diseases and for complex analysis of a wide range of biologi-
cal substances. There is hope that monoclonal antibodies will
be as effective as enzymesin chemical and technological
processes, and that they currently play a significant role in
genetic engineering research.See alsoAntibody-antigen, biochemical and molecular reac-
tions; Antibody formation and kinetics; Antibody, mono-Binding of an antibody with an antigen, as detected using X-ray
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