440
C.H.J. Lamers
actions
is
manifested
by
a
faster
rejection
of
second—set
allografts.
Nevertheless, the existence of classical anamnestic humoral responses (earlier
rise
in antibody formation, and higher antibody levels), has been doubted, as
the ratio between primary and secondary
responses
in
cyprinids
(about
10)
never
reached
the
high
levels
registered in mammals (about 100) (Desvaux &
Charlemagne, 1981;
Dorson, 1984).
However, it has to be kept
in
mind
that
the development of immunological memory is affected by 1) the ambient tempera—
ture,
2) antigen dose and delivery route, whereas
also
3)
the
time
course
between priming and boosting should be taken into account.
ad
1The effect of
temperature has been demonstrated by Rijkers et
al.
(1980ËÎ
_
1981b).
They
found antibody production in carp to sheep red blood
cells
(SRBC) at temperatures between 8 and 28°C.
However, the ability to res—
pond
in
a
typical anamnestic manner was absent when the fish were kept below
18°C.
Nevertheless, secondary responses differed from primary by
an
earlier
appearance of antibody and by being more extended.
At 20°C the secondary res—
ponse
exceeded the primary about 10 times, whereas at 24°C the ratio was
even
normal
to
mammalian standards
50
(Rijkers et al., 1980b).
ad 2.
Priming carp, with SRBC by intravenous injection
(i.v.)
resulted
in
modefate secondary responses, moreover the height of the response was pro—
portional to the antigen priming dose.
Much higher secondary
responses
were
registered
following
intra muscular
(i.m.) priming, especially in those carp
which were primed by low and moderate antigen doses (Rijkers et
al.,
1980c).
On
the
contrary Lamers et al.
(1985a) only observed moderate secondary res—
ponses
after i.m.
priming of carp
with
a
formalin
killed
A.
hydrophila
bacterin.
The
maximum
memory
level was dependent on the priming dose, and
best results were obtained with medium and high priming doses.
In
this
res—
pect
it
has
to
be mentioned that differences observed between SRBC and the
bacterial antigen might be related to the "T—independence" of some main
anti—
genic
components
of
the
bacterial
antigen (Lamers et al., 1985a;
Lamers,
1985).
Similar results were
obtained
using
the
O—antigen
preparation
of
Yersinia ruckeri
(Lamers & Van Muiswinkel, 1984), which has been shown to be a
"T—independent" antigen in mice (Anderson & Dixon, 1980).
Lamers
et
al.
(1985b) were the first to show memory formation
in
tele—
osts
following bath vaccination.
Bathing carp in a heat killed A.
hydrophila
bacterin gave no detectable antibody response.
However, it did
of memory,
as
a
second bath resulted in clear secondary responses.
This memory was maximum at 8 months after priming and was limited in time, for
it
was
gone
at
12 months after the first bath (Lamers et al., 1985b).
Furthermore,
it
appeared of prime importance to present antigen both times along
the
same
route,
as
a
bath priming was followed by an i.m.
booster the memory found no
expression as a clear secondary response.
These results
suggest the
involve—
ment
of
local processes during the responses after bath vaccination, and indicate
the importance of choosing vaccination routes, which correspond with
the
route
of
entry of the pathogen.
One more particular phenomenon needs to be*emphasized:
the devel—
opment
of memory
in the humoral immune response,
takes more time than the antibody response itself.
Maximum memory levels in carp are usually not reached
before
3
months
after the initial contact with the antigen (Rijkers et al-,
1980b;
Lamers et al., 1985a,b).
Moreover, following bath vaccination the du—
ration of memory was
limited, upto 8 months, whereas following i.m.
injection
memory had not faded away after 1 year.
This
feature should be taken into account
in
memory studies in cyprinid fish, and in vaccination trials;
it WOUld
be advantageous to keep carp, after vaccination at "optimal" temperatures in a
relatively clean environment during 2—3.
In mammals
the induction and maintenance of immunological memory
iS
related to certain structural requirements in the lymphoid organs.
In this res-
C.H.J. Lamers
actions
is
manifested
by
a
faster
rejection
of
second—set
allografts.
Nevertheless, the existence of classical anamnestic humoral responses (earlier
rise
in antibody formation, and higher antibody levels), has been doubted, as
the ratio between primary and secondary
responses
in
cyprinids
(about
10)
never
reached
the
high
levels
registered in mammals (about 100) (Desvaux &
Charlemagne, 1981;
Dorson, 1984).
However, it has to be kept
in
mind
that
the development of immunological memory is affected by 1) the ambient tempera—
ture,
2) antigen dose and delivery route, whereas
also
3)
the
time
course
between priming and boosting should be taken into account.
ad
1The effect of
temperature has been demonstrated by Rijkers et
al.
(1980ËÎ
_
1981b).
They
found antibody production in carp to sheep red blood
cells
(SRBC) at temperatures between 8 and 28°C.
However, the ability to res—
pond
in
a
typical anamnestic manner was absent when the fish were kept below
18°C.
Nevertheless, secondary responses differed from primary by
an
earlier
appearance of antibody and by being more extended.
At 20°C the secondary res—
ponse
exceeded the primary about 10 times, whereas at 24°C the ratio was
even
normal
to
mammalian standards
50
(Rijkers et al., 1980b).
ad 2.
Priming carp, with SRBC by intravenous injection
(i.v.)
resulted
in
modefate secondary responses, moreover the height of the response was pro—
portional to the antigen priming dose.
Much higher secondary
responses
were
registered
following
intra muscular
(i.m.) priming, especially in those carp
which were primed by low and moderate antigen doses (Rijkers et
al.,
1980c).
On
the
contrary Lamers et al.
(1985a) only observed moderate secondary res—
ponses
after i.m.
priming of carp
with
a
formalin
killed
A.
hydrophila
bacterin.
The
maximum
memory
level was dependent on the priming dose, and
best results were obtained with medium and high priming doses.
In
this
res—
pect
it
has
to
be mentioned that differences observed between SRBC and the
bacterial antigen might be related to the "T—independence" of some main
anti—
genic
components
of
the
bacterial
antigen (Lamers et al., 1985a;
Lamers,
1985).
Similar results were
obtained
using
the
O—antigen
preparation
of
Yersinia ruckeri
(Lamers & Van Muiswinkel, 1984), which has been shown to be a
"T—independent" antigen in mice (Anderson & Dixon, 1980).
Lamers
et
al.
(1985b) were the first to show memory formation
in
tele—
osts
following bath vaccination.
Bathing carp in a heat killed A.
hydrophila
bacterin gave no detectable antibody response.
However, it did
of memory,
as
a
second bath resulted in clear secondary responses.
This memory was maximum at 8 months after priming and was limited in time, for
it
was
gone
at
12 months after the first bath (Lamers et al., 1985b).
Furthermore,
it
appeared of prime importance to present antigen both times along
the
same
route,
as
a
bath priming was followed by an i.m.
booster the memory found no
expression as a clear secondary response.
These results
suggest the
involve—
ment
of
local processes during the responses after bath vaccination, and indicate
the importance of choosing vaccination routes, which correspond with
the
route
of
entry of the pathogen.
One more particular phenomenon needs to be*emphasized:
the devel—
opment
of memory
in the humoral immune response,
takes more time than the antibody response itself.
Maximum memory levels in carp are usually not reached
before
3
months
after the initial contact with the antigen (Rijkers et al-,
1980b;
Lamers et al., 1985a,b).
Moreover, following bath vaccination the du—
ration of memory was
limited, upto 8 months, whereas following i.m.
injection
memory had not faded away after 1 year.
This
feature should be taken into account
in
memory studies in cyprinid fish, and in vaccination trials;
it WOUld
be advantageous to keep carp, after vaccination at "optimal" temperatures in a
relatively clean environment during 2—3.
In mammals
the induction and maintenance of immunological memory
iS
related to certain structural requirements in the lymphoid organs.
In this res-