immune system of Cyprinid fish
443
(PMA)
or
allogenic (MLR) stimulation, and their abilities resembled strongly
those of mammalian lL—2.
Manning etal°
(1982b) demonstrated that culture su—
pernatants of Ml—tests contained factors that inhibited macrophage migration.
The observation of Rijkers et al.
(1981a), that passive
transfer
of
a
high
dose
of
specific antibody in carp inhibited the subsequent anti—SRBC an—
tibody response, indicates
a
regulation
by
antibody
feedback
inhibition.
Furthermore,
passive transfer of a low dose of specific antibody had a stimu—
latory effect on the subsequent response, which is probably caused by in
vivo
formation of
immune
complexes°
The
stimulating effect on the humoral EEèPSEEE
and memory formation of
immune
complexes (Secombes & Resink, 1984) has already
been mentioned.
ln mammals T—helper and suppressor lymphocytes play an important role
in
the humoral response.
The
existence
of helper and suppressor activity, alrea—
dy
mentioned
before,
has
been
clearly
demonstrated
by
means
of
the
hapten—carrier
system
and using chemically altered BSA molecules and the ef—
fect of
temperature modulation…
Both helper—memory and the
suppressor
func—
tion
were
long—lived and were still detctable at day 250 and 16 months after
priming respectively.
DEVELOPMENT 9Ê_DUNITY
Research on the development of immunocompetence of carp is of both scien—
tific
and
applied
interest.
Most
losses
in carp culture occur during the
first year,
therefore it
is
important to know at what age a fish can be effec—
tively vaccinated in order to minimize these losses.
The
lympoid tissue histogenesis of carp commences with the appearance
of
the thymus—anlage at 4 days after fertilization (a.f.) at 22°C, and it becomes
lymphopoietic by day 7 (Botham & Manning, 1981;
Van Loon etal., 1982).
Cells
bearing
surface
bound
lg (slg) were detected in the thymus or kidney by day
14, while cells with cytoplasmic lg first appeared at day
21
in
the
kidney
(Van
Loon
et
al., 1982).
Secombes et al.
(1983b) studied the appearance of
antigenic determinants on carp lymphoid cells, with the use of
MoAb
directed
against
carp
thymocytes
or
serum
lg.
lt
turned out that both the thymocyte
determinant and slg appeared earlier on thymocytes than on kidney lymphocytes,
Suggesting
the
thymus to be the primary lymphoid organ.
The spleen is prob—
ably not vital for immunological maturation, as it
is
still
in
a
rudiment
form,
when thymus and kidney lymphocytes already carry slg.
At
two
months of
age both the thymus and kidney had a quanlitatively mature appearance.
The
initial phagocytic defence, present during the period
of
lymphocyîe
immaturity,
is
soon
supplemented by CMI.
Carp fry of 18 days a.f—
at
22 C
were
capable of mounting an allograft
responSe
including
the
of
specific
memory,
which
was
effective in 5 weeks old fish
(Botham & Manning,
1981)Immunity by means of antibody takes longer to mature, and immunization
with
certain
antigens
before
this
stage
may
induce
state
of
non—responsiveness;
e.g.
4 weeks old carp could not elicit
an
antibody
res—
ponse
following immunization with the thymus dependent antigen
At
reim—
munization 3 months later, the fish failed to responsd,
whereas
animals
re—
ceiving
the
first immunization at 4 moths showed a normal
ant1—SRBC response
(Van Muiswinkel etal., 1985).
Similar results were obtained by Mughal
(1984)
in
4
weeks
old carp after immunizing with HGG.‘ The tolerogen1c effect
per—
sisted to an age of
6 months.
By the age of 9—10 weeks
HGG no longer
induced
tolerance
in
carp.
Using formalin killed
Mughal
(1984) obta—
ined different results:
4 wweks old carp responded to this antigen and upon a
second encounter an enhanced response was monitored.
443
(PMA)
or
allogenic (MLR) stimulation, and their abilities resembled strongly
those of mammalian lL—2.
Manning etal°
(1982b) demonstrated that culture su—
pernatants of Ml—tests contained factors that inhibited macrophage migration.
The observation of Rijkers et al.
(1981a), that passive
transfer
of
a
high
dose
of
specific antibody in carp inhibited the subsequent anti—SRBC an—
tibody response, indicates
a
regulation
by
antibody
feedback
inhibition.
Furthermore,
passive transfer of a low dose of specific antibody had a stimu—
latory effect on the subsequent response, which is probably caused by in
vivo
formation of
immune
complexes°
The
stimulating effect on the humoral EEèPSEEE
and memory formation of
immune
complexes (Secombes & Resink, 1984) has already
been mentioned.
ln mammals T—helper and suppressor lymphocytes play an important role
in
the humoral response.
The
existence
of helper and suppressor activity, alrea—
dy
mentioned
before,
has
been
clearly
demonstrated
by
means
of
the
hapten—carrier
system
and using chemically altered BSA molecules and the ef—
fect of
temperature modulation…
Both helper—memory and the
suppressor
func—
tion
were
long—lived and were still detctable at day 250 and 16 months after
priming respectively.
DEVELOPMENT 9Ê_DUNITY
Research on the development of immunocompetence of carp is of both scien—
tific
and
applied
interest.
Most
losses
in carp culture occur during the
first year,
therefore it
is
important to know at what age a fish can be effec—
tively vaccinated in order to minimize these losses.
The
lympoid tissue histogenesis of carp commences with the appearance
of
the thymus—anlage at 4 days after fertilization (a.f.) at 22°C, and it becomes
lymphopoietic by day 7 (Botham & Manning, 1981;
Van Loon etal., 1982).
Cells
bearing
surface
bound
lg (slg) were detected in the thymus or kidney by day
14, while cells with cytoplasmic lg first appeared at day
21
in
the
kidney
(Van
Loon
et
al., 1982).
Secombes et al.
(1983b) studied the appearance of
antigenic determinants on carp lymphoid cells, with the use of
MoAb
directed
against
carp
thymocytes
or
serum
lg.
lt
turned out that both the thymocyte
determinant and slg appeared earlier on thymocytes than on kidney lymphocytes,
Suggesting
the
thymus to be the primary lymphoid organ.
The spleen is prob—
ably not vital for immunological maturation, as it
is
still
in
a
rudiment
form,
when thymus and kidney lymphocytes already carry slg.
At
two
months of
age both the thymus and kidney had a quanlitatively mature appearance.
The
initial phagocytic defence, present during the period
of
lymphocyîe
immaturity,
is
soon
supplemented by CMI.
Carp fry of 18 days a.f—
at
22 C
were
capable of mounting an allograft
responSe
including
the
of
specific
memory,
which
was
effective in 5 weeks old fish
(Botham & Manning,
1981)Immunity by means of antibody takes longer to mature, and immunization
with
certain
antigens
before
this
stage
may
induce
state
of
non—responsiveness;
e.g.
4 weeks old carp could not elicit
an
antibody
res—
ponse
following immunization with the thymus dependent antigen
At
reim—
munization 3 months later, the fish failed to responsd,
whereas
animals
re—
ceiving
the
first immunization at 4 moths showed a normal
ant1—SRBC response
(Van Muiswinkel etal., 1985).
Similar results were obtained by Mughal
(1984)
in
4
weeks
old carp after immunizing with HGG.‘ The tolerogen1c effect
per—
sisted to an age of
6 months.
By the age of 9—10 weeks
HGG no longer
induced
tolerance
in
carp.
Using formalin killed
Mughal
(1984) obta—
ined different results:
4 wweks old carp responded to this antigen and upon a
second encounter an enhanced response was monitored.