12. IMMUNOLOGY OF FISH
479
tinguish between variations induced by methodological vicissitudes and
those that represent real evolutionary differences.
111. THE CELLULAR BASIS OF THE
IMMUNOLOGICAL RESPONSE
Much ingenious research has been devoted to discovering the cells
that produce humoral antibodies and that are responsible for the class
of reactions resulting in cellular immunity, such as are observed in
delayed hypersensitivities and transplant rejections. This is proving to
be a very complex field indeed, and one in which many questions remain unanswered. The reader is referred to the Oak Ridge Symposium
(1966) and the Cold Spring Harbor volume entitled “Antibodies”
(1968) for papers and references upon which to base further reading.
Some of the concepts that are emerging relevant to this section are as
follows.
Specialized cells are involved in the immunological reactions of
mammals termed “lymphocytes” or the “lymphoid series.” These originate
in the bone marrow along with other hemopoietic cells and appear to
differentiate into two populations, one concerned with the production
of immunoglobulins and the other with cellular immunity. As maturation proceeds, both kinds of cells are to be found, along with other cell
types, in the lymph nodes and spleen and also circulating in the blood.
The thymus gland, while not the site of immunological reactions, appears
to serve during youth as a reservoir of small lymphocytes that seed the
other lymphoid tissues with cells competent to react in immunity. The
thymus also appears to produce a hormone that “enhances” the immunological capabilities of lymphoidal cells. The lymphocytes exist in
several morphological forms including a series ranging from small
through intermediate to plasma cells, some of which proliferate markedly,
with the exception of notably mature plasma cells, following stimulation
with antigen, This series colonizes the germinal centers of the lymphoid
system and produces immunoglobulins, while the cellular immunity series
colonize the deeper regions of these organs.
The above cell types are also to be found in the circulating blood
and immunologically active sites, such as those of infection or graft
rejection. Remarkably, none of these cells, responsible as they are for
specific immunity, are phagocytic. This responsibility is that of other
leukocytes, also derived from hematopoietic tissue in the bone marrow,
479
tinguish between variations induced by methodological vicissitudes and
those that represent real evolutionary differences.
111. THE CELLULAR BASIS OF THE
IMMUNOLOGICAL RESPONSE
Much ingenious research has been devoted to discovering the cells
that produce humoral antibodies and that are responsible for the class
of reactions resulting in cellular immunity, such as are observed in
delayed hypersensitivities and transplant rejections. This is proving to
be a very complex field indeed, and one in which many questions remain unanswered. The reader is referred to the Oak Ridge Symposium
(1966) and the Cold Spring Harbor volume entitled “Antibodies”
(1968) for papers and references upon which to base further reading.
Some of the concepts that are emerging relevant to this section are as
follows.
Specialized cells are involved in the immunological reactions of
mammals termed “lymphocytes” or the “lymphoid series.” These originate
in the bone marrow along with other hemopoietic cells and appear to
differentiate into two populations, one concerned with the production
of immunoglobulins and the other with cellular immunity. As maturation proceeds, both kinds of cells are to be found, along with other cell
types, in the lymph nodes and spleen and also circulating in the blood.
The thymus gland, while not the site of immunological reactions, appears
to serve during youth as a reservoir of small lymphocytes that seed the
other lymphoid tissues with cells competent to react in immunity. The
thymus also appears to produce a hormone that “enhances” the immunological capabilities of lymphoidal cells. The lymphocytes exist in
several morphological forms including a series ranging from small
through intermediate to plasma cells, some of which proliferate markedly,
with the exception of notably mature plasma cells, following stimulation
with antigen, This series colonizes the germinal centers of the lymphoid
system and produces immunoglobulins, while the cellular immunity series
colonize the deeper regions of these organs.
The above cell types are also to be found in the circulating blood
and immunologically active sites, such as those of infection or graft
rejection. Remarkably, none of these cells, responsible as they are for
specific immunity, are phagocytic. This responsibility is that of other
leukocytes, also derived from hematopoietic tissue in the bone marrow,