The thyroid "microsomal" antibody revisited. Its paradoxical binding in vivo to the apical surface of the follicular epithelium.

We have shown that thyroid monolayers derived from the glands of patients with autoimmune thyroid disease have immunoglobulin (Ig) bound to their surface. This appears to have been deposited in vivo rather than during preparation of the monolayers, a view supported by our finding of such deposits on the apical margin of follicular cells in sections cut from these glands and stained with conjugated anti-immunoglobulin. It is likely that these deposits represent specific binding of so-called "microsomal" autoantibodies to the surface of the thyroid cells in vivo since staining of partially disrupted follicles ("half-melons") with Hashimoto serum containing microsomal autoantibodies in the indirect immunofluorescence (IFL) test, localized the antigen on the apical surface of the cells lining the follicular cavity. Thus, paradoxically, although the antigen is relatively inaccessible, autoantibodies do reach and combine with the thyroid surface in vivo and may therefore play a role in pathogenesis.

Reexpression of blood group ABH antigens on the surface of human thyroid cells in culture.

Using indirect immunofluorescence (IFL) on viable human thyroid cultures, it has been shown that, although adult follicular cells do not express blood group ABH antigens in vivo, they invariably reexpress the corresponding antigens on the cell surface when cultured in monolayers, even for very short periods. The absence of blood group antigens on noncultured thyroid cells was confirmed by negative IFL on cell suspensions obtained after enzymatic digestion of the glands, whereas these antigens were readily demonstrable on cell suspensions obtained by trypsinization of established monolayers. The quantitative expression of ABH antigens on individual thyroid cells was variable and the cell-surface IFL pattern due to binding of blood group isoantibodies was different from that given by organ-specific thyroid autoantibodies on viable cultures. Reexpression of blood group antigens by cultured thyroid cells could not be related to the secretor status of the donors, the presence of a particular source of serum in the culture medium or cell division in vitro. After 2-3 wk in culture, thyroid cells became morphologically dedifferentiated and no longer displayed blood group antigens, though they still expressed cell-surface beta 2-microglobulin. Fibroblasts present in the primary thyroid cultures were invariably negative for ABH antigens. These results demonstrate that the surface antigenic repertoire of cultured human cells is not necessarily identical to that present on the same cells in vivo. Furthermore, the possibility that blood group natural isoantibodies bind to the cell surface must be taken into account in experiments in which cultured thyroid cells are exposed to human sera.

HLA-DR expression by hair follicle keratinocytes in alopecia areata: evidence that it is secondary to the lymphoid infiltration.

There is evidence suggesting that alopecia areata (AA) may have an autoimmune pathogenesis, and it was recently reported that keratinocytes in the bulb of some hair follicles affected by this condition express class II HLA (HLA-DR) antigens, which are not present on the same cells in normal tissue. Since it has been proposed that an analogous ectopic HLA-DR expression by epithelial cells in other organs might be an early event leading to organ-specific autoimmunity, we have investigated the sequence in which perifollicular mononuclear cell (MNC) infiltration and ectopic HLA-DR expression on keratinocytes appear in recent-onset and long-standing cases of AA by immunostainings of affected and unaffected areas with monoclonal antibodies against leukocyte and HLA-DR antigens. In recent-onset AA lesions, ectopic HLA-DR expression on hair follicle keratinocytes was found only occasionally (in 3 out of 247 follicles examined) and was restricted to biopsies from the affected areas. This prevalence was significantly lower than the prevalence of hair follicles showing perifollicular MNC infiltrates in the same biopsies, and was also significantly lower than the prevalence of hair follicles showing ectopic HLA-DR expression on keratinocytes in the affected areas of longstanding cases. These findings suggest that in AA lesions the perifollicular MNC infiltration precedes the ectopic HLA-DR expression on hair follicle keratinocytes, and therefore argue against the notion of a primary role for that ectopic HLA-DR expression on epithelial cells in triggering the putative autoimmune response in AA.

Topical minoxidil in alopecia areata: no effect on the perifollicular lymphoid infiltration.

The therapeutic value of topical minoxidil in alopecia areata (AA) has been investigated in recent years, with variable results. Although the mechanism whereby minoxidil may stimulate hair regrowth in some cases of AA has not yet been elucidated, there have been reports of a decrease in the perifollicular infiltrates of mononuclear leukocytes (MNC)--particularly T lymphocytes--that characterize this condition, in patients "responding" to topical minoxidil. In a randomized and double-blind study, we have investigated the effect of 5% topical minoxidil versus placebo (vehicle alone) on the extent and composition of the perifollicular MNC infiltration in 20 patients having extensive AA (26-99% scalp hair loss). The proportions of hair follicles showing perifollicular infiltration by MNC and their main subsets were determined with histologic and immunohistochemical stainings of scalp biopsies obtained before treatment, after 12 weeks of randomized double-blind minoxidil versus placebo treatment, and after 12 additional weeks during which all patients received minoxidil. Six of the patients showed cosmetically acceptable hair regrowth (CAHR) at the end of the 24 weeks and this was associated with a significant decrease in the proportions of follicles infiltrated by total T and B lymphocytes, macrophages, and Langerhans cells at week 12, and by total T lymphocytes at week 24. However, no significant differences in the extent or composition of the perifollicular infiltrates were detected at week 12 between patients receiving minoxidil and placebo, or between the week-12 and week-24 biopsies of those patients who first received placebo and then minoxidil. These findings indicate that in AA the reduction in perifollicular T-cell infiltration associated with CAHR is not attributable to an effect of topical minoxidil.

Ectopic expression of HLA class II antigens on thyroid follicular cells: induction and transfer in vitro by autologous mononuclear leukocytes.

Ectopic expression of HLA class II antigens by thyroid follicular cells (TFC) might trigger the immune recognition of TFC-specific surface constituents by self-reactive T helper/inducer lymphocytes, with the consequent generation of organ-specific autoimmunity. To explore the alternative possibilities underlying this ectopic expression, i.e. that it either reflects a primary abnormality of the TFC or is secondarily induced by the autoimmune attack itself, we employed immunofluorescence staining of monolayers cultured from thyroid tissue of patients with autoimmune thyroid disease as well as neoplastic, nodular, and normal thyroid tissues to assess the role that autologous mononuclear leukocytes (MNC) and serum factors play in HLA class II induction and modulation in vitro. In all Graves' disease (GD) tissues that initially displayed HLA-DR (DR) antigens, this expression was transient. Primary TFC cultures from tissues with tumor-associated chronic thyroiditis (CT) showed more widespread and persistent DR expression than did cultures from GD tissues. However, in contrast with the findings in GD, there was no correlation between ectopic DR expression on TFC from the CT areas and the presence of organ-specific autoimmune markers. DR expression by TFC was detected in only one of the five nontoxic nodules studied, and involved a small proportion (approximately 20%) of the TFC. A similarly low proportion of DR-positive TFC was found in cultures from two papillary carcinomas, while much stronger DR expression was seen on TFC cultured from the contralateral lobes affected with CT. Only one of four follicular adenomas expressed DR on about 35% of the cultured TFC. In contrast with the rapid extinction of DR expression on TFC cultured from GD tissues after depletion of infiltrated MNC, DR antigen loss did not occur or was significantly delayed when parallel TFC monolayers were cocultured in the presence of autologous MNC from the intrathyroidal infiltrates. Coculture of DR-negative TFC from normal tissues with autologous peripheral blood MNC in individuals without detectable thyroid autosensitization also resulted in pronounced induction of DR expression on the TFC. Purified T lymphocytes from the same peripheral blood MNC preparations, however, did not induce DR expression on these normal TFC. Similarly, MNC obtained from two follicular adenomas, mostly macrophages, did not induce DR expression when cultured with autologous TFC from the same lesions. Addition of 15% autologous serum did not prevent progressive extinction of DR expression on TFC cultured from GD or tumor-associated CT tissues after depletion of infiltrated MNC.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunofluorescent vascular pattern due to EVI antibody of Chagas' disease. Its diagnostic value.

One hundred fifty-six of 1,250 sera from patients with presumed connective tissue and related diseases showed vascular staining on mouse liver cryostat sections when they were routinely checked for antinuclear factor by the indirect immunofluorescence test. In a third of the cases, the vascular immunofluorescent pattern was given by the EVI antibody reacting with the plasma membrane of striated muscle fibers and endothelial cells, as has been recently described to occur in Chagas' disease. This led to the detection of previously unsuspected Trypanosoma cruzi infection in 67.8% of the serum samples in which the EVI antibody was detected after observation of a positive vascular pattern with mouse liver cryostat sections. On the other hand, no significant relationship between Chagas infection and sera with other anti-striated-muscle immunofluorescent patterns that also showed a vascular staining on mouse liver cryostat sections was established. Consideration of the vascular pattern observed with the EVI antibody on mouse liver cryostat sections can be helpful in detection of previously ignored T. cruzi infection in patients who have connective-tissue diseases and related conditions. This is of interest in view of the fact that anergic immunodepressive therapy, often used in these patients, significantly alters the host-parasite relationship and may lead to severe dissemination of the parasite.

Investigation of the EVI antibody in parasitic diseases other than American trypanosomiasis. An anti-skeletal muscle antibody in leishmaniasis.

The specificity of a circulating antibody observed in American trypanosomiasis and reacting with endocardium, blood vessels, and the interstitium of striated muscle (EVI factor) was evaluated in the indirect fluorescent antibody test with 60 sera from patients with malaria, leishmaniasis, echinococcosis, amebiasis, African trypanosomiasis, toxoplasmosis, and trichinosis, collected from areas where Chagas' disease is not endemic. Two sera, 1 from a patient with Plasmodium falciparum malaria and 1 from a patient with a relapse pretreatment post kala-azar dermal leishmaniasis, were positive for the EVI factor. In the leishmaniasis group, 3 of 8 sera reacted with 0ovine, murine, and human skeletal muscle. In this reaction, which differs from the EVI test, the sarcolemma and the intracellular structures were stained.

Mobile mammography: the technologist's role.

This article discusses the role of the radiologic technologist in a mobile mammography screening program targeted at the economically disadvantaged in Dade County, Fla. It describes the development of process, structure and outcome standards used to guide and evaluate both the program and the radiologic technologist within this setting, highlighting the technologists' valuable contributions to the program.

Aberrant expression of class II HLA antigens by the target cell: cause or consequence of the autoimmune aggression?

Since the aberrant HLA-DR expression on thyroid follicular cells (TFC) has been found in glands already having an ongoing immune response, the possibility exists that this ectopic expression is not the primary event leading to the infiltration by autoreactive lymphocytes, but rather a consequence of that infiltration. We have explored that possibility in studies on the behaviour of TFC from normal and autoimmune glands with respect to their expression of HLA-DR antigens when they are cultured with or without autologous mononuclear cells from the intrathyroidal infiltrates or peripheral blood. Our findings suggest that 1) the ectopic expression of class II HLA antigens by TFC in autoimmune conditions is not the result of a primary or intrinsic defect of those cells but a consequence of their response to an environmental stimulus operating in situ; 2) this stimulus appears to be the lymphoid infiltration itself; 3) there are no significant differences in the responses given by TFC from autoimmune and normal glands. In alopecia areata, another presumably autoimmune condition characterized by the presence of lymphoid infiltration precedes that ectopic HLA-DR expression in vivo. In addition, we have found that human adrenocortical cells in the zona reticularis of adult glands normally express HLA-DR antigenic determinants. Therefore, the co-existence of both HLA-DR and potentially autoantigenic cell-surface constituents does not seem to be a sufficient stimulus to trigger an organ-specific autoimmune response.

HLA-DR expression by adrenocortical cells of the zona reticularis: structural and allotypic characterization.

We previously reported that human adrenocortical cells in the zona reticularis of normal glands express antigenic determinants recognized by HLA-DR monoclonal antibodies (MoAbs). In the present study, it is shown that these adrenocortical HLA-DR determinants are present on glycoproteins having similar structural characteristics, regarding subunit composition and molecular weight, to those of HLA-DR molecules present on immunocomponent cells. Furthermore, adrenocortical HLA-DR molecules include serologically-defined genetically-appropriate allotypic specificities, detectable by immunostainings with both HLA-DR human alloantisera and MoAbs against polymorphic HLA-DR determinants. The finding of a normal expression of HLA-DR antigens by these highly differentiated and biosynthetically active endocrine cells gives support to the notion that MHC class II molecules may perform biological functions in addition to those related to the immune response.

Luteinization of human granulosa cells in vivo is associated with expression of MHC class II antigens.

We previously described the presence of MHC class II (HLA-DR) antigens, structurally similar to those on lymphoid cells and bearing the genetically-appropriate allotypic determinants, on human adrenocortical cells in the zona reticularis of normal glands. We now report a similar expression by granulosa-lutein cells (GLC) in corpora lutea (CL) of normal ovaries, as detected by indirect immunofluorescence techniques with the use of mouse monoclonal antibodies (MAb). In some cases, GLC were also positive for HLA-DQ and -DP antigen expression. Neither granulosa nor theca interna cells in large antral follicles of the same ovaries showed any detectable expression of MHC class II antigens. Moreover, theca-lutein (paralutein) cells, identified by their reactivity with specific human autoantibodies in 5 of the 7 human CL examined, were also negative. Similarly, GLC, but not paralutein cells, in rhesus monkey CL showed significant cross-reactivity with anti-HLA-DR MAb. In contrast, lutein cells in ovaries from either cycling or 7-day-pregnant rats were negative for MHC class II (Ia) antigen expression. Expression of MHC class II antigens by human granulosa cells after their luteal transformation confirms the normal inducibility of certain human steroidogenic cells at the time of their further functional differentiation and enhanced biosynthetic activity, and suggests that these molecules may have additional functions beyond serving as restriction elements in the immune response.

Induction of HLA-DR expression on thyroid follicular cells by cytomegalovirus infection in vitro. Evidence for a dual mechanism of induction.

Cytomegalovirus (CMV) infection of primary cultures established from human thyroid nodular and normal (paranodular) tissues resulted in induction of human leukocyte antigen (HLA) DR expression on thyroid follicular cells (TFC), as detected by cell-surface immunofluorescence staining with monoclonal antibodies (MAb). Two distinct modalities of induction were observed. The first type occurred in cultures of normal tissue obtained from CMV-seropositive but not seronegative donors, was detected on 30% to 50% of the TFCs, even though the vast majority of these cells failed to show any morphologic or antigenic evidence of individual CMV infection, and was associated with production of gamma-interferon (gamma-IFN) in vitro. The induced molecules displayed the characteristic DR polypeptide profile on immunoprecipitation and electrophoretic analysis. These results demonstrate that CMV infection of normal thyroid cultures may induce DR expression on TFCs in the absence of pre-existing lymphoid infiltrates and suggest that the induction is the result of an in vitro response to CMV by previously sensitized immunocompetent cells present in these primary cultures. Such a response, associated with the release of gamma-IFN, would induce DR expression on neighboring uninfected cells. The second mode of induction occurred in all CMV-infected cultures, regardless of their tissue origin (nodular or normal) or the serologic status of the donors. Up to 50% of infected TFCs at a late stage of infection, having fully developed CMV antigen-positive intranuclear inclusions, also displayed the cell-surface DR-related determinant recognized by one of the four anti-DR MAbs used. This induction was restricted to TFCs, while CMV-infected fibroblastoid cells present in the monolayers were invariably negative. Induction by CMV of major histocompatibility class II antigens on human epithelial cells may have significant implications in the development of normal immune responses against local viral infection, the enhancement of alloimmune rejection of grafted organs, and the generation of organ-specific autoimmune responses.

Human cytomegalovirus ie2 negatively regulates alpha gene expression via a short target sequence near the transcription start site.

Repression of human cytomegalovirus alpha (immediate-early) gene expression is under the control of the viral ie2 gene. Here we show that ie2 negatively regulates gene expression directed by the strong cytomegalovirus enhancer via a specific 15-bp target sequence (which we term cis repression signal [crs]). This crs is located between -14 and +1 relative to the transcription start site and will function in an orientation-independent fashion, consistent with repression occurring at the transcriptional level. Repression is dominant over transactivation by ie1 gene products. The crs (5'-CGTTTAGTGAACCGT-3') does not contain previously recognized binding sites for cellular transcription factors, and a precise copy is not found elsewhere in the human cytomegalovirus genome. The position of the signal near the transcription start site appears to be important in function; addition of the crs near the transcription start site of a heterologous promoter, from the thymidine kinase gene of herpes simplex virus type 1, conferred cytomegalovirus ie2-dependent repression upon this promoter. Thus, we propose that an ie2 gene product or an induced cellular protein mediates repression by binding to crs. Negative regulation of alpha gene expression may be important during viral replication or latency.

Mitochondrial antibodies in chronic liver diseases and connective tissue disorders: further characterization of the autoantigens.

The heterogeneity of mitochrondrial autoantibodies in a variety of diseases states has been critically re-examined by a combination of immunofluorescence staining (IFL) and complement fixation tests (CFT). The different mitochondrial IFL patterns described by other workers were confirmed and extra criteria using new substrates are presented for their differential recognition. Biochemically defined mitochondrial subfractions were used in the CFT to confirm and extend the IFL classifications. The 'M1' cardiolipin antibodies of syphilis did not react with the ATPase fraction but the antigen was present in all membrane preparations and found to be chemically resistant. The major antibody specificity of the 'M3' pattern associated with drug-induced pseudolupus syndrome is a firmly bound, outer membrane component; and a second, minor reactivity is apparently to a mercurial-insensitive antigen present in the chloroform-released ATPase preparation. The 'M5' antibody pattern correlates with a digitonin-sensitive outer membrane component. Although it was not possible to differentiate within the group of liver diseases between the 'M2' antibodies of primary biliary cirrhosis and the previously described 'M4' antibodies of other chronic liver diseases, several antibody specificities were demonstrated. All sera from liver disease patients contain the antibody directed against a mercurial-sensitive protein found in the chloroform-released ATPase preparation, and, in addition, varying titres of antibodies against two or more mercurial-resistant membrane components, of which at least one is on the inner membrane and one on the outer membrane.

Adrenocortical cells of the zona reticularis normally express HLA-DR antigenic determinants.

A distinct population of normal human adrenocortical cells from adult glands spontaneously express HLA-DR, and occasionally also HLA-DQ, antigenic determinants in vivo and in vitro, as detected by immunofluorescence techniques using monoclonal antibodies on frozen tissue sections, primary cultures, and viable cell suspensions. In vivo, these antigenic determinants were found to be confined to the compact-type cells in the zona reticularis. In vitro, the adrenocortical identity of these HLA-DR+ cells was conclusively established by the characteristic change in their morphologic features induced by ACTH1-24 and by the simultaneous detection of tissue-specific adrenal autoantigens in double-label immunofluorescence staining. The cell surface expression of HLA-DR determinants by compact cells persisted in culture for several weeks and was not significantly affected by treatment with ACTH1-24. On the other hand, fetal adrenocortical cells of both transient and definitive zones were invariably negative for the expression of these HLA Class II antigenic determinants. Because normal human adrenocortical cells also express on their surface the molecules which constitute specific autoantigens in autoimmune adrenalitis, these findings argue against the notion that an ectopic HLA-DR expression associated with an otherwise "silent" autoantigen might trigger an organ-specific autoimmune response against endocrine cells. In addition, the expression of HLA-DR determinants by viable normal reticularis cells provides a readily detectable surface marker which may allow the physical separation of this population for studies in vitro.