The relationship of delayed hypersensitivity and circulating antibody to experimental allergic thyroditis in inbred guinea pigs

Transfer of an autoimmune nephrosis in the rat by means of lymph node cells

An autoimmune nephrosis produced in rats by repeated injections of kidney extract with Freund's adjuvant has been transferred by means of lymph node cells to recipient animals rendered tolerant by neonatal injection with spleen cells from prospective donors. Transfer of the disease was manifested in the recipients by the development of proteinuria, hypoalbuminemia, hypercholesterolemia,and histological changes. The latter consisted of glomerular epithelial swelling, increase in basement membrane material and the presence of protein droplets in the glomerular and tubular epithelium. Appropriate control experiments were negative. Attempts to transfer with serum were unsuccessful. The transfer described is believed to provide evidence for an immunological mechanism for kidney and adjuvant induced nephrosis in the rat.

THE EFFECT OF 6-MERCAPTOPURINE AND AMINOPTERIN ON EXPERIMENTAL IMMUNE THYROIDITIS IN GUINEA PIGS

The influence of 6-mercaptopurine and aminopterin was studied on immune response and immune thyroiditis in guinea pigs immunized with thyroid extract. 1. Both compounds depressed delayed hypersensitivity to thyroglobulin and immune thyroiditis. 2. Antibody formation to thyroglobulin was strongly depressed by aminopterin but not significantly influenced by 6-mercaptopurine. 3. Immune response and thyroiditis were suppressed as long as the compounds were administered; after discontinuation of treatment, immune response and thyroiditis appeared in the same time intervals as observed in control animals after initiation of immunization. 4. Treatment with 6-mercaptopurine and aminopterin 10 days after immunization lead to suppression of delayed hypersensitivity and thyroiditis. 5. Treatment with 6-mercaptopurine of animals after onset of thyroiditis lead to suppression of delayed hypersensitivity and disappearance or diminution of round cell infiltration in the thyroid. 6. The results are discussed in terms of the pathogenesis of experimental immune thyroiditis, the mode of action of these antimetabolites on this experimental immune disease, and in view of the potential value of these compounds in human diseases.

THE COURSE OF EXPERIMENTAL AUTOALLERGIC THYROIDITIS IN INBRED GUINEA PIGS. THE PATHOLOGIC CHANGES AND THEIR RELATIONSHIP TO THE IMMUNE RESPONSE OVER A 2 YEAR PERIOD

Experimental allergic thyroiditis produced in strain 13 histocompatible guinea pigs after a single immunization with thyroid extract and Freund's adjuvant was followed for more than 2 years. The disease appeared as early as 5 days and persisted for the entire period studied, although it regressed in the later stages. Circulating antithyroid antibody was detected at low levels as early as 7 days after immunization, and increased to a peak at the time of most severe disease. Thereafter, antibody decreased, but was still detectable in most animals as late as 2 years. There was no correlation between antibody levels and extent of disease except at the 7 week stage. Delayed sensitivity to thyroid antigen was found as early as 5 days after immunization, and appeared to precede the development of thyroiditis in many animals. It correlated closely with thyroiditis at 5 days and 7 weeks. At 6 months, the delayed skin reaction was decreased, and a modified type of reaction appeared which persisted as long as 26 months. The time relationship of delayed sensitivity, thyroiditis, and circulating antibody continue to confirm the role of delayed sensitivity in the pathogenesis of this disease. The accumulated data demonstrating production of thyroiditis without antibody, and the converse, tend to strengthen this view.

Influence of adjuvants on the induction of autoantibodies to the thyrotropin receptor

To determine the influence of adjuvant on the induction of antibodies to thyrotropin receptor (TSHR), we immunized BALB/c mice with a extracellular domain of the TSHR (ETSHR) protein in complete Freund's adjuvant (CFA), Titer Max (TM) and Gerbu. Similarly, control groups of mice were immunized with bovine serum albumin (BSA) in each of the different adjuvants. As determined by ELISA, ETSHR given along with CFA elicited high titers of antibodies to ETSHR which were mainly restricted to the IgG1 subclass. Mice immunized with ETSHR in TM also developed high titers of anti-ETSHR antibodies but had higher levels of both IgG1 and IgG2a. However, immunization with ETSHR in Gerbu resulted in low titers of antibodies, restricted to IgG1 subclass. Immunization of mice with BSA in each of the three adjuvants induced higher antibody titers to BSA. The subclass of antibodies in mice immunized with BSA in CFA and TM were predominantly IgG1 and IgG2a with lower levels of IgG2b, whereas in Gerbu treated group, antibody to BSA was restricted to IgG1 subclass. Analysis of specificity of antibodies against ETSHR, in mice immunized with ETSHR, revealed that irrespective of the adjuvant used, the dominant reactivity was against peptide 1 (AA 22-41) with weaker reactivity against several other. peptides. The only exception was in mice immunized with ETSHR in TM which also showed significant reactivity against peptide 23 (AA 352-371). Mice immunized with the ETSHR in CFA or in TM showed elevated levels of serum TSH binding inhibitory immunoglobulins (TBII). However, mice immunized with ETSHR in Gerbu, which had lower titers of antibodies to ETSHR, showed normal TBII levels. These studies showed that adjuvant composition could influence the titer, subclass and fine specificity of antibodies to ETSHR which in turn could affect the development of TBII activity.

Induction of experimental autoimmune myasthenia gravis with acetylcholine receptors using a nonionic block copolymer as adjuvant

To induce autoimmune diseases in animals, the auto-antigen has to be emulsified in adjuvants (e.g., complete Freund's adjuvant) containing microbial products such as Mycobacterium tuberculosis. But these powerful immunoadjuvants are not without undesirable immune response to the microbial proteins and induction of adjuvant arthritis, which could interfere with the antigen specific autoimmune response to be tested. This study was performed to evaluate the requirement of microbial products in the induction of experimental autoimmune diseases, and to identify an adjuvant without unwanted immune responses. C57BL/6 mice were inoculated with Torpedo acetylcholine receptors (T-AChR) emulsified in Titermax (TM), an adjuvant containing nonionic block copolymer and no microbial products, and evaluated for experimental autoimmune myasthenia gravis (EAMG) susceptibility. Mice immunized with T-AChR in TM demonstrated characteristic myasthenic muscle weakness with electrophysiological defect, elevated serum anti-AChR antibodies, and muscle AChR loss. None of the mice that received TM alone had muscle weakness, serum anti-AChR antibodies or muscle AChR loss. The data imply that microbial products are not critical in the induction of autoimmune diseases like myasthenia gravis in mice. Further, nonionic block copolymer could be an ideal adjuvant in the induction of autoimmune diseases in animals.

Experimental thyroid autoimmunity in the dog

Thyroid autoimmunity was induced in 6 crossbred dogs by a single injection of thyroid extract in complete Freund's adjuvant alone, or followed by reimmunization with thyroid extract and incomplete Freund's adjuvant or peanut oil. Total thyroxine levels, autoantibodies to thyroglobulin and thyroid microsomal antigen and thyroid histopathological changes were sequentially monitored for up to 150 days. All dogs developed fluxuating levels of thyroid autoantibodies detectable by enzyme-linked immunosorbent-assay (ELISA). Histopathological damage was observed in one or more thyroid gland biopsies in 4 of the dogs, in 3 cases the lesions were of lymphocytic thyroiditis, in the fourth dog the lesion was a granulomatous reaction. Histopathological thyroid damage was observed in biopsies taken during periods of maximal autoantibody titer. Fixed immunoglobulin was not demonstrable in thyroid gland biopsies by direct immunofluorescence. In 5 dogs total thyroxine levels fell to below the normal range at some period during the study. However in only one dog did this correlate with a time when biopsy findings revealed histopathological thyroid damage. High levels of thyroid autoantibody may indicate histopathological thyroid damage in dogs, however lower levels of thyroid antibody may be found without evidence of histological damage or alteration in thyroid function.

Immunopharmacological studies on experimental glomerulonephritis

Immunopharmacological studies on modified nephrotoxic serum (NTS) nephritis in rats were conducted. The modified NTS nephritis was produced by an intravenous (i.v.) injection of NTS in a subnephrotoxic dose (sub-dose) into the rats which had been previously immunized with rabbit IgG (RGG) and complete Freund's adjuvant (CFA). In previously immunized rats, typical nephritic syndrome was demonstrated with respect to the elevation of urinary protein, serum cholesterol, blood urea nitrogen (BUN) and histopathologic scores of the kidneys. No changes in complement levels were found. By adoptive transfer experiments, it was found that sensitized lymphocytes were essential for causing the nephritis. The potency of the sensitized lymphocytes was reinforced by passing them through a nylon wool or Sephadex G-10 column after treatment with rabbit anti-rat F(ab')2 antibody and complement. The administration of cyclophosphamide, prednisolone, tilorone or cis-1-methyl-4-isohexylcyclohexane carboxylic acid (IG-10) showed a clear remission of nephritis. Cobra venom factor (CoVF) and Cu-chlorophyllin complement inhibitors showed a contradictory efficacy on the nephritis. CoVF which decreased the serum CH50 value did not produce any remission of the nephritis, whereas Cu-chlorophyllin, which slightly decreased CH50 values produced a significant decrease in urinary protein and serum cholesterol. The macrophage-toxic agents carrageenan and dextran sulfate, also did not produce a remission of nephritis. These findings suggest that the participation of T cells is important for the onset of this nephritis and that macrophages and complement do not appear to be involved.

Humoral and cellular immune response to thyroglobulin in different inbred rat strains

The role of humoral and cellular immunity in experimental autoimmune thyroiditis was examined in inbred rat strains. A significant relationship between thyroiditis and both in vitro proliferative responses to rat thyroglobulin and in vivo delayed hypersensitivity (ear test) was observed in responsive rats. Comparison of the autoantibody response and thyroiditis among rat strains revealed no direct correlation of RT1 genotype with either parameter.

Thyroid transplantation developing autoimmune thyroiditis following thymectomy and irradiation

Post-irradiation transplantation of normal thyroids under the renal capsule of syngenetic thymectomized and irradiated (Tx-X) rats leads to the development of thyroiditis in the ectopic grafted thyroids. A close correlation was observed between the extent of the lesions in the grafted and recipient's own thyroid. The histopathology of both grafted and recipient thyroid was similar and was characterized by infiltration with mononuclear cells together with some plasma cells. Conversely, grafting of affected thyroids from Tx-X rats to normal animals resulted in the regression of the lesion in the graft and no evidence thyroiditis was observed in either the graft or the recipient's thyroid when these were examined 60 days post-grafting. Thyroids derived from normal animals grafted to syngenetic normal rats were found to remain healthy and intact over a 60-day period. In contrast to normal animals, Tx-X rats were unable to reject totally in transplanted allogeneic thyroids by 28 days post-grafting, suggesting that some impairment of cell-mediated immunity follows this treatment. These findings indicate that the pathological change occurring in the thyroid gland of Tx-X rats is not attributable to the local effect of irradiation of the thyroids and adds further support to the concept that the process is immunologically mediated by thyroid-specific circulating components in the absence of normal immune regulatory function.

Electron microscopic and immunohistochemical studies on Hashimoto's thyroiditis

Three types of Hashimoto's thyroiditis, lymphoid type (L-type), oxyphilic epithelium (O-type) and pronounced epithelial destruction (p-type), were ultrastructurally and immunohistochemically studied. In both the L-type and the O-type, two different kinds of follicles, active and degenerated ones, were ultrastructurally found. Although the follicular conformation was generally conserved, focal basement membrane damage was frequently found around the generated follicles. Some plasma cells and lymphocytes transversed the basement membranes and could be seen in the spaces between adjacent epithelial cells. In the P-type, most epithelial cells were replaced by fibrillar fibrous bundles, and destructive products probably derived from epithelial cells were scattered in the stroma. Immunoglobulin (IgG, IgA and IgM) deposittions was found not only in some basement membranes, colloid, epithelial cells and peeled-off cells in the follicles but also in the stroma. Some of the infiltrating plasma cells and lymphocytes had immunoglobulins in the cytoplasm. The intensity o the positive staining was by far the strongest for IgG, and the number of immunoglobulin-containing immunocytes was also the largest for IgG.

Autoimmune murine thyroiditis IX. Relationship of humoral and cellular immunity to thyroiditis in high and low responder mice

Good responder (C57/Br/cd) and poor responder (C57BL/10) mice were immunized with mouse thyroid extract in Freund's complete adjuvant. The good responder mice first showed antibody to thyroglobulin on the seventh day while the poor responder animals had slightly lower titers and antibody did not appear until day 12. The first signs of thyroid infiltration appeared on day 4 in the responder strain, and severe lesions were seen between the third and fifth week. In contrast, the poor responder mice showed almost no evidence of infiltration. The macrophage disappearance reaction, a measure of cell-mediated immunity, was similar in the responder and nonresponder strains.

Spontaneous autoimmune thyroiditis in the BUF rat

The inbred BUF rat develops autoimmune thyroiditis spontaneously. The incidence is related to the age of the animal and is increased by neonatal thymectomy and by treatment with methylcholanthrene. Autoantibodies to thyroglobulin can be demonstrated by indirect immunofluorescence and hemagglutination, but skin tests are negative. The "spontaneous" autoimmune disease may be due to the conjunction of an unusually vigorous immunological response to thyroglobulin and the loss of thymic suppressor function.

Parietal cell antibodies. Part II. Cytotoxic activities of parietal cell antibodies. Experiment 1. The observations on cytotoxic activities of parietal cell antibodies to normal human parietal cells in vitro. Experiment 2. The histochemical changes of rat stomach after administrations of rabbit anti-rat gastric mucosa sera

Cytotoxic activities of P.C.A. to normal parietal cells were demonstrated in vitro. The changes were very similar to those of thyroid cells provoked by Hashimoto serum. The cytotoxic component was found to be immunoglobulin G. Complement was not added. Rabbit anti-rat gastric mucosa sera had no effects on the gastric secretion in rats, but histochemical changes were demonstrated. The changes were transient and returned to the normal state 60 minutes after injection of Anti-RGM sera. Activities of succinic dehydrogenase were most affected, particularly 3 minutes after injection. Decrease of activities gradually recovered to the normal condition. The comparison of C.A.G. with C.Th. was made. By the comparison between C.A.G. and C.Th., and by the results of experiments, the author considers that C.A.G. has the immunologically identical aspects with C.Th.. The author also considers that some immunological mechanisma are playing a role in the pathogenesis of C.A.G.

Insoluble particulate antigen(s) in cell-mediated immunity of autoimmune thyroid disease

Cell-mediated immunity (CMI) in patients with Grave's disease, chronic thyroiditis, and primary hypothyroidism was observed by assay of lymphocyte-mediated cytotoxicity (LMC) and leukocyte migration inhibition (LMC). Lymphocyte responsivity to phytohemagglutinin (PHA) is normal in these disease. In the LMC assay, lymphocytes of patients in each category responded to the antigens of thyroid homogenates, but not purified human thyroglobulin. Cytotoxicity is least in Graves disease and most obvious in primary hypothyroidism. In the LMI assay, patients lymphocytes responded to thyroid microsomal--mitochondrial antigens, but not to thyroid cell sap. Lymphocytes of Graves disease patients also responded to liver microsomal mitochondrial antigens. The particulate antigens lost activity when solubilized by ultrasonication or KCL extraction. There is no correlation between the PHA responsivity of lymphocytes and thyroid function, or between CMI and serum antithyroid antibodies or thyroid size. Treated and untreated patients had similar evidence of CMI. These data indicate that function of thymus-derived lymphocyte in vitro is not disturbed in autommune thyroid disease and that CMI against thyroid antigens can be demonstrated by assay of LMC and LMI. Insoluble particulate antigens appear more important than soluble antigens in CMI. LMC, resumably induced by soluble cytotoxic factor, "lymphotoxin," may play an important role in the progress of the autoimmune thyroid disease to hypothyroidism.

Roles of T and B lymphocytes in the termination of unresponsiveness to autologous thyroglobulin in mice

The data presented in this paper support the hypothesis that unresponsiveness to autologous thyroglobulin (Tg) exists in the T cells and responsiveness exists in the B cells. Such a conclusion is based on the results of antigen-binding studies where few, if any, thymocytes recognized syngeneic Tg. Comparable numbers of antigen-binding lymphocytes for syngeneic Tg were found in the spleens of normal intact mice and of nude mice. The latter fact suggested that B cells exist which recognize self-constituents. From antigen-suicide experiments, a clearer picture of the susceptibility of B cells to iodinated self-antigen and of the obligatory role of antibody in the induction of lesions was developed. Only bone marrow cells (B cells) were affected by [(125)I]syngeneic Tg, in which case the incidence of lesions was diminished. From adoptive transfer experiments, the results demonstrate that unresponsiveness may be terminated by immunization with a mixture of heterologous (cross-reacting) Tg's. In this situation T cells are required since a B-cell reconstituted host failed to make antibody (plaque-forming cells) and to develop lesions. T cells in this form of an unresponsive state may recognize determinants on the heterologous Tg unrelated to autologous Tg and as such stimulate the normal complement of B cells to produce antibody that both reacts with autologous and heterologous Tg.

Cellular events during the induction of experimental thyroiditis in the rabbit

With a modification of the Jerne plaque technique to enumerate plaque-forming cells (PFC) to bovine and rabbit thyroglobulin, the cellular kinetics of the antibody response were followed during two 5-day series of injections of an aqueous preparation of bovine thyroglobulin. The results support the suggestion that thyroiditis in the rabbit is mediated by antibody. The peak PFC appear in the spleen at the end of the second series of injections and are considerably greater for bovine than for rabbit thyroglobulin. PFC also appear in the thyroid gland; however, the numbers of PFC for bovine and rabbit thyroglobulin were similar, and they did not reach a peak until 7 days after the peak PFC in the spleen. There was an excellent correlation between the appearance of PFC in the thyroid gland and the appearance of thyroid lesions. The disappearance of antibody to rabbit thyroglobulin from the serum also correlated with the appearance of lesions. Migration inhibition factor (MIF) activity was not produced at any time throughout the study when rabbit thyroglobulin was added to peritoneal exudates of immunized rabbits containing circulating antibody to rabbit thyroglobulin. MIF activity was observed when bovine thyroglobulin was added to similar cells in the later stages of the study after lesions were present.

Autosensitization in vitro

Autosensitization of rat or mouse lymphoid cells against syngeneic fibroblast antigens was induced in cell culture. Rat lymphoid cells autosensitized by this method were able to produce immunospecific lysis of syngeneic target fibroblasts in vitro or GvH reactions in newborn rats. Autosensitized mouse spleen cells mediated similar GvH reactions when injected into newborn mice. The nature of the system used to induce immunity in vitro appears to argue against the possibility that lymphocytes capable of reacting against self-antigens could arise by mutation in cell culture. Hence, it is likely that cells potentially reactive against self-antigens preexisted in the lymphoid cell donors. The ability of autosensitized cells to mediate immune reactions in vivo suggests that the immunogenic self-antigens present on sensitizing fibroblasts also were accessible in the intact animals. Loss of natural self-tolerance in vitro, therefore, can be explained most simply by the existence of lymphocytes which are reversibly tolerant to self. Hence, ontogenic elimination of potentially self-reactive cells may not be the only basis for natural tolerance. Regulatory mechanisms, such as antigen excess, may have to function in vivo to prevent differentiation of self-tolerant lymphocytes. These regulatory mechanisms appear to be annulled in the cell-culture system. The present system thus may offer a new approach to studies of tolerance and regulation of cellular immunity.

Passive transfer of experimental allergic thyriditis, delayed hypersensitivity to thyroglobulin and anti-thyroglobulin antibody formation in inbred Lewis rats

Inbred Lewis rats regularly develop experimental allergic thyroiditis, delayed skin hypersensitivity and Arthus reactivity, and produce anti-thyroglobulin antibodies 14–21 days after immunization with bovine thyroglobulin in adjuvant.

Attempts have been made to transfer thyroiditis to normal rats by means of thymus, spleen or lymph node cells, as well as by serum containing anti-thyroid antibodies. The following types of lymphoid cells were used: viable or non-viable cells from donors immunized with bovine thyroglobulin in adjuvant, cells from donors sensitized only with adjuvant, cells from donors immunized with adjuvant alone and mixed with thyroglobulin prior to the injection into recipients, and cells from donors injected with egg albumin in adjuvant.

Thyroglobulin-sensitive lymph node cells were most effective in transferring thyroiditis, delayed skin hypersensitivity and anti-thyroglobulin antibody production; spleen cells exhibited slight activity, whereas thymus cells were incapable of inducing immune responses. Passively produced thyroiditis was characterized by mild inflammatory lesions. The incidence of delayed skin hypersensitivity in positive recipients was much higher than the occurrence of thyroiditis. Prolonged treatment of intact animals with immune or normal rat serum did not induce lesions typical of allergic thyroiditis.

It was concluded that passive induction of experimental allergic thyroiditis can be accomplished in inbred Lewis rats by immunologically active lymphoid cells. The role of anti-thyroid antibodies in the pathogenesis of thyroiditis was discussed.

The cellular infiltrate in Hashimoto's disease and focal lymphocytic thyroiditis

The lymphoid cells infiltrating the thyroid in three examples of Hashimoto's disease and three examples of focal lymphocytic thyroiditis have been studied by light and electron microscopy. The cell types found were small lymphocytes, plasma cells and plasmablasts, immunoblasts, and cells morphologically intermediate between immunoblasts and small lymphocytes. The infiltrate was similar in the two conditions studied and resembled the cell response found in other conditions thought to be due to delayed hypersensitivity. It is considered that these similarities support the views that focal lymphocytic thyroiditis is a focal form of Hashimoto's disease and that delayed hypersensitivity is important in the pathogenesis of these conditions.

Antigens in thymus and muscle effective in inducing experimental autoimmune thymitis and the release of thymin

Hartley guinea-pigs immunized with homologous thymus or muscle in Freund's complete adjuvant (FCA) developed experimental autoimmune thymitis, with lymphocytic accumulations in the thymic medulla and electromyographic evidence of a block in neuromuscular transmission similar to that of humans with myasthenia gravis. These animals immunized with homologous tissues had a higher incidence of thymitis than animals similarly immunized with bovine tissues; yet, unlike the latter, no serum autoantibodies could be demonstrated by immunofluorescence.

Muscle was considered to be thymitogenic because there are common antigens in striated muscle and myoid cells of the thymus. Muscle was thymitogenic in doses down to 50 μg while thymus was thymitogenic in doses down to 5 μg. Since muscle contains far more muscle anitgen than thymus, these results were interpreted as showing that thymus probably contains thymitogen(s) which are distinct from, and even more potent than, muscle thymitogen.

Animals with thymitis also had electromyographic evidence of neuromuscular block to single stimuli, increasing with repetitive stimulation. The incidence of neuromuscular block closely paralleled the incidence of thymitis, whether the thymitis was induced by thymus or muscle. Thus the release of thymin, the thymic substance causing neuromuscular block, appeared to be a general consequence of inflammation of the thymus and was not related to the type of antigen initiating thymitis.

The biological effects of anti-thyroid antibodies. Thyroid eosinophilia following passive transfer of anti-thyroglobulin antibody

Guinea-pigs that received a passive transfer of rabbit antiserum to guinea-pig thyroglobulin developed an eosinophilic infiltrate of the thyroid. The infiltrate varied in intensity in different guinea-pigs, developed over a 1–24-hour period, and resolved in 4–9 days. The antibody that was injected was localized to the interstitial areas of the thyroid gland. It is proposed that thyroglobulin is also present in the interstitial areas either normally or as a result of the antiserum injection and that the eosinophils appeared in response to the presence of thyroglobulin—anti-thyroglobulin complexes in these areas.