Review of studies on the immunological capacity in the bursectomized chick

Veterinary Immunology and Immunopathology, 16 (1987) 77-84 Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands

REVIEW OF STUDIES ON THE IMMUNOLOGICAL MIZED CHICK

CAPACITY

OkMORIYA Department of Bacteriology, Saitama Medical Iruma, Saitama, 350-0~, Japan (Accepted

26 February

77

IN THE BURSECTO-

School,

Moroyama,

1987)

ABSTRACT Moriya, 0., 1987. Review of studies on the immunological capacity in the bursectomized chick. Vet. Immunol. Immunopathol., 16:

77-84.

This paper summarizes data on the immunological capacity in the bursectomized chick. A series of experiments described by Glick and Sadler represented the functional importance of the bursa of Fabricius for the humeral immunity in chicken. Later studies of immune responses in bursaless chickens reported by Lerner et al. contributed to our knowledge of bursa-independent humeral immunity and demonstrated anextra-bursal site for B-cell differentiation. Bursectomy at an early stage of chicken development changes the immune responses after hatching. Here I present my current understanding of embryonic B-cell populations (bursa-dependent and independent) following in eve bursectomy which may influence B-cell differentiation with reference to our experiments on J chain production. INTRODUCTION In eve bursectomy

(Bx) has proven highly

chicken and such treatment aid in depleting

immunosuppressive

is routinely used by investigators

certain B-cell populations

The role of the bursa of Fabricius

(Warner et al., 1969).

in the development

system of the chicken was first investigated Bx before hatching

resulted

specific

antibody formation

(Cooper et al., 1966).

cant reduction

in a marked impairment

however,

in the ability to produce

buted to the fact that at the embryonic differentiating tissues. provide ponses.

an excellent Recently,

opportunity

however,

ponse has been detected

0165-2427/87/$03.50

Ig.

This has been attri-

stage only a few B-cells lymphoid

before hatching may therefore to study the nature of B-cell res-

a bursa-independent

(Glick,

of

The same treat-

does not lead to a signifi-

in the bursa have reached peripheral

Chicken bursectomized

of the immune

by Glick and Sadler

(1961).

ment a few days after hatching,

in as an

humeral

immune res-

1977; Hirota et al., 1976; Lerner

© 1987 Elsevier Science Publishers B.V.

78 et al., 1971;

Sato and Abe,

197S).

Furthermore,

repeated immuni-

zation led to normal or higher levels of IgM, but had a negligible influence

on IgG production

(Hirota et al., 1976). propose

in embryonally bursectomized

In this connection,

that at least some B-cell precursors

side the bursa of Fabricius Lerner et al., 1971; independent

immune

(Glick,

Sato and Abe,

1979).

has been designed mainly to examine sites for B-cell differentiation

for further understanding

out-

The existence of a bursaconcept.

This review

the existence of extrabursal

with attention to the bursal deli-

(testosterone)

ground of the agammaglobulinemia

can differentiate

1977; Hirota et al., 1976;

system is an interesting

neation following hormonal

chicken

some investigators

treatment,

and the back-

in the bursectomized

chick embryo

of the effect of Bx on the immune response

after hatching. I.

Possible mechanisms underlying

bursectomized

Bx ?

suppression in the

chick embryo

This section describes question:

immune

what changes

Jankovic

experiments

addressed to the following

in the development of B-cells are caused by

et al.(197~)

reported

that Bx of the early embryo

caused a depletion of lymphocytes containing IgM-containing

cells in bone marrow,

ther reported a decrease

the Bu marker and of

spleen and thymus.

They fur-

in the density of y-chain determinant on

the surface of B-cells in the bursectomized

embryo.

The impaired

capacity for synthesis of cell surface ~ lead to decreased binding cells.

I have demonstrated J chain-positive

antigen-

cells and

observed cells covered with Ig determinants

on their surface detect-

able by the fluorescent

although the J chain-

positive nants

antibody technique,

cells were not the same as those covered with Ig determi-

(Moriya and Ichikawa,

, 198~,a,b).

1979; Moriya,

By using this fluorescent

the number of splenic J chain-positive sterone-treated

embryos

in ovo with testosterone. chain synthesis

a reduction in

cells was found in testo-

(Moriya and Ichikawa,

(197~) demonstrated 7S monomeric of bursectomized

1983; Moriya and Ichikawa

technique,

198~,a).

Ivanyi

IgM in the sera of chicken treated

The monomeric

IgM detected in the sera

chick does not contain J chain. or block the secretion of Ig.

Bx may affect J

By chemical reduct-

ion of whole Ig, a lower levl of J chains was detected in the serum obtained from testosterone-treated alkaline urea/polyacrylamide the result of a deficiency

gels

chicks by electrophoresis (Fig. 1).

on

This finding may be

in the B-cell system.

Recently,

a

79

Q~O O

Fig. i. Densitometer analysis of J chain peak in serum separated by electrophoresis on alkaline urea/PAGE. Sample sera were reduced with 2-ME and alkylated with iodoacetamide. ( - - ) Normal serum, .....) Bx chicken serum, both from 20 day, before hatching.

defect in the generation of light chain diversity chickens has been reported by Jalkanen et al. ing of the generation

in the relative

Another possible

(198h) and a block-

of Ig diversity by in ovo Bx has also been

reported by Huang and Dreyer a decrease

(1978).

These findings partly

mechanism of immune inhibition chicken.

effect when transferred

(1976)

also reported

suppressive. Grenbenau bursal

In addition

et al. (1979)

These findings

2.

immune

suppressive

activity by injecting cells are induced

for the immune regulation.

system

that the bursa is the only source of IgH

cells

The immunodeficiency

(Alten et al., 1968; Glick and Sadler caused by Bx, however,

defined in the primary immune response. erythrocytes

Palladino

chicken treated with testosterone.

and are responsible

, IgA and IgG producing 1961).

into normal chicken.

that spleen and bone marrow cells are

induced

It is widely accepted

(197h) have

chicken have a

support the concept that suppressor

Bursa-independent

suppress~

to these adult agammaglobulinemias,

cells from embryonic

by testosterone

is active

Blase et al.

shown that bone marrow cells from bursectomized et al.

imply

size of the B-cell pool due to Bx.

ion by cells from bursectomized suppressive

in bursectomized

was not significantly

seems to be

IgH production

affected

to sheep

if the chicken was

80

treated with the same antigen repeatedly (Sat0 and Abe, 1975). Interestingly,

the capacity for antibody production, as measured

by serum IgM level and the number of plaque-forming Cells, was increased by Bx (Sato and Abe, 1975).

These findings imply that

the bursa has a role in the maturation from IgM- to IgG-producing cells and suggest the possible presence of bursa-independent production.

IgM

These authors propose the possibility that the bursa

is not essential for all antibody productions.

Similarly, Jankovic et al. (1975) postulated that the chicken has two antibody producing systems, one bursa-dependent and the other bursa-independent.

Lerner et al.

(1971) suggested that the bursa functions as a micro-

environment for inducing the transition from IgM production to IgG or IgA production, and that another lymphoid tissue, such as the bona marrow, is available in bursaless chick. Thus, the studies described here indicate that the bursa provides the microenvironment leading repertoire.

to

I

Somatic mutations for the expansion of the Ig

However, the gene rearrangements for the production of different isotypes of Ig molecules probably occur at within and extrabursal sites. Comparative studies of B-cell development in the

twrsa

support

for

and bone marrow of the chicken after hatching provide the

view

that bone marrow plays an important role in

tha generation of the B-cell repertoire (Kincade et al., 1973). For this reason, some role of the bone marrow in the generation and seeding of B-cells is probably not different in hormonally bursectomixed chick from normally developed chick. suggested

Subba Rao et al. (1978)

that elevated IgM levels may represent the specific anti-

bodies to a considerable number of environmental antigens. this

However,

is not reasonable bec,ause IgG and IgM production in bursaless

chickens may be due to the failure of a switch from IgM to IgG production, thus allowing continuous production of IgM without negative control of IgG.

Another explanation for immune enhance-

ment by Bx is bursa-derived suppressor cells that is class-specific (Droge, 1971). The origin of suppressor cells in the bursa is, however, not known exactly. Studies are therefore in progress to evaluate more precisely the functional subpopulations in the bursa. 3.

Functional B-cell existance at extrabursal sites in embryonic

lymphoid tissues Elevated levels of IgM production, induced by Bx, by the bursa independent immune system have been shown previously. Some investigators argue that Bx can totally prevent the development of antibody

81 forming capacity, and the possible presence of functional B-cells in extrabursal sites is suggested (Lerner et al., 1971; Sato and Abe, 1975). An adoptive cell-transfer system reported by Toivanen et al. (1972,a,b, 1973, 1974) has resolved the problem of the presence of a microenvironment for B-cell differentiation.

Survival

pattern, gain in body weight and microscopic morphology of lymphoid tissues were studied to assess the function of B-cells taken from embryonic lymphoid tissues in addition to the specific antibody formation. These authors considered that the cells derived from liver and yolk sac from embryonic stages contain the B-cell function for humoral immunity and the embryonic bursal cells were most effective on the reconstitution of the bursa dependent lymphoid system. Eskola and Toivanen (1976) further demonstrated that bursa cells, even from different stages of development, were the only cells capable of functional and morphological reconstitution. They propose, on the basis of their findings, that cells from embryonic spleen, bone marrow or thymus had no reconstituting effect on the recipient's humoral immune system, indicating that these embryonic tissues taken just before hatching do not include precursors for B-cell llne. erent

By taking cells from embryos at diff~

stages of development, bone marrow cells were shown to be

almost incapable of functional reconstitution 1972,a,b).

(Toivanen et al.,

Different results based on the repopulation capacity

have been presented by Moore and 0wen (1967). from the 13th to 18th days of incubation,

They showed that

spleen, bone marrow and

peripheral blood contain cells capable of reconstituting.

We have

also reported reconstituting capacity in bursa-impaired embryos, and the bursal and splenic cells taken from normal embryos at the corresponding stage were effective on the splenic frequencies of B-cell line except antibody-forming capacity (Moriya and Ichikawa, 1978).

These results lead to the concept that some embryonic

lymphoid tissues may act as differentiation sites of the bursaindependent B-cell lineage. It is possible that the early removal of the bursa by Bx leads to activation of potential sites for B-cell differentiation. Moticka (1975) postulated that the bone marrow could be such a non bursal site.

Moticka's suggestion is in complete agreement with

observations on J chaln-positive cells in testosterone-treated embryos (Moriya and Ichikawa, 198~,a).

J chaln-positive cells in

embryonic bone marrow were present in almost the same number as in untreated controls.

This finding implies a negligible effect of

82 testosterone suggesting

on the B-cell

the possible

the microenvironment

subpopulations

presence

in bone marrow,

of accessory

lymphoid

again

tissues

as

for B-cell differentiation.

CONCLUSION Studies on Bx of embryos have some B-cell

function.

shown that in ovo Bx can impair

The immunodeficient

to involve

B-cell deficiency

mechanism.

On the contrary,

increased

partly caused by Bx in some cases. complicated

by such contradictory

ly a confusion

observations.

as to the role of the bursa It is possible,

a bursa-independent

B-cell

attempted

to analyze

ing the mechanisms embryonic

ACKNOWLEDGEMENT The author wishes sity,

for critical

in studyduring the

Understanding

elucidation

of these

of the chicken

K. Sato,

and many valuable

that

review has

advances

particularly

treatment.

to thank professor

reading

immune

role in the chick

The present

some of the recent

mechanisms would lead to a further B-cell system.

There is present-

in the humoral

a different

system.

of B-cell delineation,

stage by testosterone

is made more

but not yet demonstrated,

line plays

from that of the bursa-dependent

suppressive

levels of serum IgM are

Interpretation

system of chicken.

mainly

state induced by Bx seems

and in part an active

Nagoya Univer-

suggestions.

REFERENCES Alten, P.V.J., Cain, W.A., Good, R.A. and Cooper, M.D., 1968. Gamma globulin production and antibody synthesis in chickens bursectomized as embryos. Anat. Rec. I~6:23-26. Blase, R.M., Weiden, P.L., Koski, I. and Dooley, N., 1974. Infectious agammaglobulinemia transmission of immunodeficiency with grafts of agammaglobulinemic cells. J. Exp. Med. 140: 1097-1101. Cooper, M.D., Peterson, R.D.A., South, M.A. and Good, R.A., 1966. The function of the thymus system and the bursa system in the chickens. J. Exp. Med. 123:75-102. Droge, W., 1971. Amplification and suppressive effect of thymus cells. Nature, 23~:549-551. Eskola, J. and Toivanen, A., 1976. Cell transplantation into immunodeficient chick embryos. Reconstituting capacity of cell f~om the bursa of Fabricius, spleen, bone marrow, thymus and liver of 18-day old embryos. Cell. Immunol. 26:68-77. Glick, B. and Sadler, C.R., 1961. The elimination on the bursa of Fabricius and reduction of antibody production in birds from eggs dipped in hormone solution. Poultry Sci. h0:185-189. Glick, B., 1977. The bursa of Fabricius and immunoglobulin synthesis. Int. Rev. Cytol. 48:345-~02.

83 Grenbenau, M.D., Lerman, S.P., Chi, D.S. and Thorbecke, G.J., 1979. Transfer of agammaglobulinemia in the chicken. I. Generation of suppressor activity by injection of bursal cells. Cell. Immunol. 51:92-108. Hirota, Y., Suzuki, T., Chazono, Y. and Bito, Y., 1976. Humoral immune responses characteristics of testosterone propionate treated chicks. Immunol. 30:3hl-3h8. Huang, H. and Dryer, W., 1978. Bursectomy in ovo blocks the generation of immunoglobulin diversity. J. Immunol. 121:1738-17h7. Ivanyi, J., 1975. Immunodeficiency in the chicken. Ii. Production of monomeric IgM following testosterone treatment or infection with Gumboro disease. Immunol. 28:1015-1021. Jalkanen, S., Jalkanen, M., Granforts, K. and Toivanen, P., 198h. Defect in the generation of light chain diversity in bursectomized chickens. Nature, 311:69-71. Jankovic, B.D., Knezevic, Z., Isakovic, K., Mitrovic, K., Markovic, M.B. and Rajcevic, M. 1975. Bursal lymphocytes and IgM-containg cells in chicken embryos bursectomized at 52-6h hours of incubation. Eur. J. Immunol. 5:656-659. Kincade, P.W., Self, K.S. and Cooper, M.D., 1973. Survival and function of bursa-derived cells in bursectomized chickens. Cell. Immunol. 8:93-102. Lerner, K.G., Glick, B. and McDuffie, F.C., 1971. Role of the bursa of Fabricius in IgG and IgM production in the chicken: Evidence for the role of a non-bursal site in the development of humoral immunity. J. Immunol. i07:h93-503. Lydyard, P.M., Grossi, C,E. and Cooper, M.D. 0ntogeny of B cells in the chicken. I. Sequential development of clonal diversity in the bursa. J. Exp. Med. Ihh:77-97. Moore, W.T. and Owen, J.J.T., 1967. Chromosome marker studies in the irradiated chick embryo. Nature, 215:1081-1082. Moriya, 0. and Ichikawa, Y., 1978. Immune reconstitution in the immunodeficient chickens by transfer of embryonic lymphoid cells. Microbiol. Immunol. 22:269-277. Moriya, O. and Ichikawa, Y., 1979. 0ntogeny of spontaneous antigen binding cells in developing chick embryos. Immunol. 37:857861. Moriya, 0., 1983. Ontogeny of lymphocytes expressing J chain in chickens. Cell. Immunol. 80:78-83. Moriya, O. and Ichikawa, Y., 198h, a. J chain positive cells in bursectomized chicks. Immunology Letters, 7:289-291. Moriya, 0. and Ichikawa, Y., 198h, b. Loss of J chain during the primary response in chickens. Cli. Exp. Immunol. 58:719-723. Moticka, E.J., 1975. Development of immunological competence in chicken. Amer. Zool. 15:135. Palladino, M.A., Lerman, S.P. and Thorbecke, G.J. 1976. Transfer of hypogammaglobulinemia in two inbred chicken starin by spleen cells from bursectomized donors. J. Immunol. 116:1673,1676. Sato, K. and Abe, S., 1975. The possible presence of a bursaindependent IgM producing system in chicks. Immunol. 28:293298. Subba Rao, D.S.V., McDuffie, F.C. and Glick, B., 1978. The regulation of IgM production in the chick: Roles of the bursa of Fabricius. J. Immunol. 120:738-787. Toivanen, P., Toivanen, A. and Good, R.A., 1972,a. Ontogeny of bursal function in chicken, i. Embryonic stem cell for humoral immunity. J. Immunol. 109:1058-1070. Toivanen, P., Toivanen, A., Linna, J. and Good, R.A., 1972, b. 0ntogeny of bursal function in chicken, ii. Post embryonic stem cell for humoral immunity. J. Immunol. 109:1071-1080.

84 Toivanen, P. and Toivanen, A., 1973. Bursal and postbursal stem cells in chicken. Functional characteristics. Eur. J. Immunol 3:585-593. Toivanen, P., Toivanen, A. and Tamminen, P., 1974. Bursal and postbursal cells in chicken. Occurrence of postbursal cells in bone marrow, thymus and spleen. Eur. J. Immunol. ~:h05-1410. Warner, N.L., Uhr, J.W., Thorbecke, G.J. and Ovary, Z., 1969. Induction of agammaglobulinemia and the loss of all antibody forming capacity by hormonal bursectomy. J. Immunol. 103: 1317-1330.