Homologous Thyroglobulin Research Articles

Lymphocyte locomotion in experimental allergic thyroiditis

Experimental allergic thyroiditis was produced in rats by immunization with homologous thyroglobulin (Tg). The mechanisms of lymphocyte accumulation of the thyroid lesion were analyzed by using this experimental model. The sensitized lymph node cells were cultured with Tg. After 72 hr, the cell-free supernatant was found to contain a chemotactic factor for sensitized lymphocytes. Lymph node lymphocytes from animals immunized 3 weeks previously were the best source of such sensitized lymphocytes while the cells at the latter stage could not produce the factor. The culture supernatant was applied to a Sephadex G-100 gel filtration column. The results indicate that the molecular weight of the factor is around 12,400. Among lymph node lymphocytes, nylon-wool column nonadherent lymphocytes were the most responsive; adherent lymphocytes were not responsive. Thyroglobulin itself did not chemoattract lymphocytes obtained from rats immunized with Tg. This phenomenon was in contrast to macrophage chemotaxis in the same model in which macrophage itself can move toward Tg. In any event, these results seem to indicate that a chemotactic lymphokine may be playing an important role in the pathogenesis of lymphocyte accumulation of the thyroid lesion.

Macrophage locomotion in experimental allergic thyroiditis of the rat

Wistar King A rats were immunized with homologous thyroglobulin in complete Freund's adiuvant with pertussis vaccine. The relationship between different parameters of the immune response to thyroglobulin and the inflammatory reaction of the thyroid gland was observed. The severity of thyroiditis reached its peak 3 weeks after immunization in all animals. Regression of both the inflammatory cell reaction and the degree of follicular damage began from the 4th week. Hemagglutinating antibody titer to thyroglobulin reached its peak 3 to 4 weeks after immunization and persisted until the 10th week. Delayed type skin hypersensitivity to thyroglobulin was less well correlated with the degree of thyroiditis. However, the migration inhibition of peritoneal exudate cells by thyroglobulin in vitro correlated with the development of thyroiditis, and approximately 50% inhibition was observed 2 to 5 weeks after immunization. Chemotactic activity of the macrophages to thyroglobulin by the modified Boyden chamber technique was markedly increased in the 3rd week after immunization. No chemotactic response to kidney extract was noticed during the time of observation. These results give a clue to the mechanism of accumulation of macrophages in the thyroid in experimental allergic thyroiditis.

A new mechanism for the reabsorption of thyroid iodoproteins: selective fluid pinocytosis.

Rat thyroid hemilobes were incubated in presence of exogeneous, heterologous and homologous thyroglobulins. The median density of the thyroglobulin molecules originally added to the medium was compared with that of the molecules remaining at the end of a three-hour incubation period (37 degrees C). A certain degree of specificity in the reabsorption process of thyroglobulin was found: the uptake of homologous molecules (rat) was higher than heterologous (hog) molecules. The median density of the iodoproteins remaining after the incubation did not change for the heterologous whereas it shifted towards lower density for the homologous thyroglobulins (equilibrium labelled, 35 iodine atoms/molecule). In addition, rat follicular cells display selectivity in the endocytosis of homologous thyroglobulin. Among the rat molecules, the normally iodinated are taken up more actively than the lowly iodinated or newly synthesized ones. Dissimilarity in the median density of the thyroglobulin molecules before and after endocytosis was only evident for the equilibrium-labelled, normally iodinated rat preparation: the disappearance from the medium of 25-30% of exogenous iodoproteins was sufficient to lower significantly the median density of the remaining molecules. This means that the thyroglobulin molecules having higher density are taken up preferentially by the tissue. A mechanism involving specific interactions between the iodoproteins and the surface of thyroid cell is suggested.

Allogeneic effect on induction of thyroglobulin antibodies and thyroid lesions in mice.

All previous attempts failed to induce thyroglobulin antibodies or thyroid infiltrates in mice immunized with homologous thyroglobulin without adjuvants. However, an allogeneic effect obviated the need of adjuvants for triggering thyroglobulin-reactive lymphocytes to produce thyroglobulin antibodies or thyroid lesions.

Cellular basis of the genetic control of immune responsiveness to murine thyroglobulin in mice

Cell transfer experiments were performed to determine the role of T and B lymphocytes in the genetic control of autoimmune thyroiditis. Adult female BALB/c mice H-2d), poor responders, were thymectomized, lethally irradiated, and reconstituted with T lymphocytes (thymus cell suspensions), B lymphocytes (bone marrow cells treated with anti-θ serum and complement), or T and B lymphocytes from (RF × BALB/c)F1 good responder mice. Chimeras were immunized with homologous thyroglobulin, and the thyroid antibody and pathology index were assessed. T lymphocytes but not B lymphocytes could transfer responsiveness to thyroglobulin. Adult thymectomized mice had a markedly decreased immune response to thyroglobulin. Homozygous nude (nu/nu) mice did not develop thyroiditis in contrast to heterozygous (nu/+) littermates.

Cellular and humoral immune responses in experimental autoimmune thyroiditis.

Guinea pigs were immunized once with homologous thyroglobulin in complete Freund’s adjuvant and observed for lesions in the thyroid gland as well as for different parameters of the immune response to thyroglobulin. In individual animals there was a significant correlation between the development of thyroiditis and delayed type skin hypersensitivity to thyroglobulin and the inhibition of migration of peritoneal exudate cells by thyroglobulin. Thyroid lesions and haemagglutinating antibodies to thyroglobulin were less well correlated. Lymphoid spleen cells from immunized animals lysed thyroglobulin coated chicken erythrocytes. Sera from these animals contained antibodies which in the absence of complement rendered lymphocytes from normal guinea pigs cytotoxic for thyroglobulin coated chicken erythrocytes. Presence of thyroid lesions was correlated to both these phenomena. The incidence of thyroiditis and cytotoxicity of immune spleen cells reached their peak 3–4 weeks after immunization and then decreased. The inhibition of macrophage migration reached its peak before the establishment of thyroid lesions and decreased at the same time as the incidence of thyroiditis decreased. Skin reactivity, haemagglutinating antibodies and antibody induced cytotoxicity of normal lymphocytes remained unchanged during the observation period.

Inhibition of migration of normal guinea pig blood leukocytes by homologous immune gamma 2-globulin in the presence of specific antigen.

Guinea pigs were immunized with homologous thyroglobulin in complete Freund’s adjuvant or BCG and killed tubercle bacilli. Their sera contained γ<sub>2</sub>-globulin, which in the presence of specific antigen inhibited <i>in vitro </i>the migration of blood leukocytes from nonimmunized animals. The γ<sub>1</sub>-globulin fraction did not. The relationship between the inhibitory activity of the two globulins and their hemagglutination titers was studied.

The role of mycobacteria and the effect of proteolytic degradation of thyroglobulin on the production of autoimmune thyroiditis.

Data are presented which suggest that the initial event involved in experimental autoimmune thyroiditis following injection of rabbits with homologous thyroglobulin in complete Freund's adjuvant is alteration of the thyroglobulin. Alteration of the thyroglobulin does not occur during incorporation into the adjuvant or in vitro storage in the adjuvant, and the mycobacteria in the adjuvant have no direct effect on the thyroglobulin. Most likely, the alteration results from an increase in hydrogen ion concentration within cells or local areas in the granuloma and the subsequent action of proteolytic enzymes. These conditions are probably established in the granuloma as the result of neutrophilic response to the mycobacteria in the adjuvant. Rabbits injected with aqueous preparations of homologous thyroglobulin partially degraded in vitro with pepsin at acid pH produced antibody to native thyroglobulin and developed thyroiditis. Most of these rabbits responded to a subsequent injection of native thyroglobulin given 1 month later.

Experimental thyroiditis in complement intact and deficient mice following injections of heterologous thyroglobulins without adjuvant.

SummaryExperimental thyroiditis and thyroglobulin autoantibodies have been produced in both complement intact and deficient mice by injections of a mixture of heterologous (cross-reacting) thyroglobulins without adjuvant. The severity of the immune response and incidence of thyroid lesions in mice varied from strain to strain. The Swiss Webster and A/JAX strains had the highest mean hemagglutinating antibody titer to homologous thyroglobulin in addition to being susceptible to thyroid lesions, whereas the complement intact and deficient strains of B10-D2/SN new line, DBA/1J, B10-D2/SN old line and DBA/2J showed autoantibody production without any definite thyroid lesions. Present data do not substantiate a necessary role for components of complement which are activated after the third component of complement in the production of either thyroiditis or autoantibodies in mice.

Isoantigens of Thyroglobulin and Their Significance in Experimental Autoimmune Thyroiditis

Summary Isoantibodies and isoantigens of bovine thyroglobulin were demonstrated in the present experiments. Isoantibodies to bovine thyroglobulin were easily detected in rabbits rendered unresponsive to bovine thyroglobulin obtained from a single gland and then injected with pooled arsanil-sulfanil bovine thyroglobulin prepared from glands obtained from numerous animals. Sera from such animals contained precipitating and hemagglutinating antibodies to both the tolerated bovine thyroglobulin and pooled (unaltered) bovine thyroglobulin. After absorption of the sera with the tolerated thyroglobulin, the sera no longer reacted with the tolerated thyroglobulin but still reacted with the pooled thyroglobulin. In contrast to rabbits made unresponsive to an individual thyroglobulin, rabbits unresponsive to pooled bovine thyroglobulin did not lose their unresponsive state following injections of pooled arsanil-sulfanil bovine thyroglobulin. The role of isoantigens in experimental thyroiditis is discussed. It appears that isoantigens of thyroglobulin are involved in the termination of a natural unresponsiveness to autologous thyroglobulin with production of autoimmune thyroiditis following injections of altered homologous thyroglobulin.

The Behavior of Autologous Thyroglobulin in the Circulation of Rabbits Immunized with Either Heterologous or Altered Homologous Thyroglobulin

Summary Injection of adequate doses of NaI131 into iodine deficient but otherwise normal rabbits results in disruption of thyroid structure with release of I131 thyroglobulin into the circulation. In these rabbits, the I131 thyroglobulin is eliminated at an exponential rate with a half-life of 2.3 days. The release of autologous I131 thyroglobulin in rabbits previously immunized with either arsanil-sulfanil-thyrogobulin (homologous) or a heterologous thyroglobulin causes a secondary stimulation resulting in an immune elimination of the I131 thyroglobulin and production of antibody to native rabbit thyroglobulin. Complexes formed between the circulating I131 thyroglobulin and the newly synthesized antibody deposit along the glomerular basement membrane of the kidney resulting in mild glomerular inflammatory changes and proteinuria.

In Vivo Behavior of Homologous and Heterologous Thyroglobulin and Induction of Immunologic Unresponsiveness to Heterologous Thyroglobulin

Summary Homologous and heterologous thyroglobulins were observed to have an in vivo behavior, following injection, very similar to that of homologous and heterologous serum proteins. Following injection, thyroglobulin equilibrated between the intra- and extravascular fluid spaces, and persisted in both the blood and lymph with elimination at an exponential rate. A consistent immune response was made to the injected heterologous thyroglobulin but not to the injected homologous thyroglobulin. As with serum proteins, the half-life of heterologous thyroglobulin was usually shorter than the homologous thyroglobulin and varied with the host animal. An acquired immunologic unresponsiveness was induced in rabbits by periodic injections of a heterologous bovine thyroglobulin starting on the day of birth. Thyroglobulin was found to be an excellent antigen for the study of various immunological mechanisms. In addition to the properties listed above, in small doses heterologous thyroglobulins induce a much greater antibody response than comparable heterologous serum proteins.

Immunologic Unresponsiveness to Allergic Thyroiditis in Guinea Pigs

Summary Immunologic unresponsiveness to autoimmune thyroiditis was induced in guinea pigs. A single injection of homologous thyroglobulin accompanied by eight daily injections of cyclophosphamide prevented the onset of thyroiditis after a disease-inducing challenge of guinea pig thyroglobulin. An injection of guinea pig thyroglobulin or cyclophosphamide alone did not produce specific immunity or unresponsiveness to a subsequent challenge with thyroglobulin. Picrylated guinea pig thyroglobulin or bovine thyroglobulin, in conjunction with cyclophosphamide, did not induce immunologic unresponsiveness to guinea pig thyroglobulin.

The immune response in guinea pigs injected with heterologous and altered homologous thyroglobulin.

The immune response in guinea pigs injected with heterologous and altered homologous thyroglobulin.

THE INDUCTION OF AUTOIMMUNITY IN RABBITS FOLLOWING INJECTION OF HETEROLOGOUS OR ALTERED HOMOLOGOUS THYROGLOBULIN.

Experimental autoimmunity was produced in rabbits following injection of altered homologous thyroglobulin. The thyroglobulin was altered by coupling to chemically defined haptens and by heating. With some preparations antibody to native thyroglobulin as well as thyroid lesions were produced. Injections of thyroglobulin coupled to the diazonium derivatives of arsanilic acid and sulfanilic acid were effective when given in either soluble form or incorporated into incomplete Freund's adjuvant) while injections of the same preparations precipitated by alum had relatively little effect on production of antibody or induction of lesions. The injection of native thyroglobulin in soluble form, incorporated into incomplete adjuvant or precipitated by alum usually resulted in production of little or no antibody and only rarely in the formation of lesions. The injection of a heterologous thyroglobulin into rabbits resulted in the production of antibody reacting with both the heterologous and rabbit thyroglobulin, but no thyroid lesions were observed.

Alterations in the Development of Experimental Allergic Thyroiditis Induced by Injection of Homologous Thyroid Extract

Summary The effect of 4 to 5 intraperitoneal and subcutaneous injections of guinea pig thyroid extract in saline on the development of experimental allergic thyroiditis in the guinea pig was studied; thyroiditis was induced by the injection of homologous thyroid extract in complete Freund's adjuvant. When these “nonsensitizing” injections were given either before, during or following the challenge injection, there was a marked, but temporary, suppression of thyroiditis at 12 days following sensitization, followed by a rapid recovery to control levels during the following 2 weeks. There was also a corresponding temporary suppression of delayed skin reactions and antibody to homologous thyroglobulin, which, in the group treated prior to sensitization, was also temporary. No suppression was obtained with comparable injections of bovine thyroid extract in saline. The relationship between this form of suppression and other forms of immunologic unresponsiveness in discussed.

Suppression of Experimental Allergic Thyroiditis, Delayed Sensitivity and Antibody Formation to Homologous Thyroglobulin in Guinea-Pigs by Prior Injection of Adjuvant

Suppression of Experimental Allergic Thyroiditis, Delayed Sensitivity and Antibody Formation to Homologous Thyroglobulin in Guinea-Pigs by Prior Injection of Adjuvant

Thyroglobulin antibodies in multiple thyroid diseases.

AUTOIMMUNIZATION to autogenously released thyroglobulin has recently been implicated as a causative factor in Hashimoto's thyroiditis and spontaneous myxedema. Circulating thyroglobulin antibodies have been demonstrated in the serum of patients with these diseases and serves as a basis for this hypothesis.1 2 3 4 5 Animal studies further support this thesis, for homologous thyroglobulin injection produces antibodies and lymphocytic destruction of thyroid tissue.3 , 6 7 8 Diseases other than thyroiditis and spontaneous myxedema seemed likely to offer opportunity for extrathyroidal circulation of thyroglobulin, and hence antibody formation. Accordingly we studied subjects with and without thyroid disease, determining the prevalence of circulating thyroglobulin antibodies in each group. The . . .