The Human la System

CD8+ T Cell Phenotype and Function in Childhood and Adult-Onset Connective Tissue Disease

CD8+ T cells are cytotoxic lymphocytes that destroy pathogen infected and malignant cells through release of cytolytic molecules and proinflammatory cytokines. Although the role of CD8+ T cells in connective tissue diseases (CTDs) has not been explored as thoroughly as that of other immune cells, research focusing on this key component of the immune system has recently gained momentum. Aberrations in cytotoxic cell function may have implications in triggering autoimmunity and may promote tissue damage leading to exacerbation of disease. In this comprehensive review of current literature, we examine the role of CD8+ T cells in systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis, polymyositis, and dermatomyositis with specific focus on comparing what is known about CD8+ T cell peripheral blood phenotypes, CD8+ T cell function, and CD8+ T cell organ-specific profiles in adult and juvenile forms of these disorders. Although, the precise role of CD8+ T cells in the initiation of autoimmunity and disease progression remains to be elucidated, increasing evidence indicates that CD8+ T cells are emerging as an attractive target for therapy in CTDs.

Immunomodulatory Effects of Vitamin D in Thyroid Diseases

Vitamin D is a secosteroid with a pleiotropic role in multiple physiological processes. Besides the well-known activity on bone homeostasis, recent studies suggested a peculiar role of vitamin D in different non-skeletal pathways, including a key role in the modulation of immune responses. Recent evidences demonstrated that vitamin D acts on innate and adaptative immunity and seems to exert an immunomodulating action on autoimmune diseases and cancers. Several studies demonstrated a relationship between vitamin D deficiency, autoimmune thyroid disorders, and thyroid cancer. This review aims to summarize the evidences on the immunomodulatory effect of vitamin D on thyroid diseases.

Diagnostic and Prognostic Relevance of the Immunophenotype in Acute Myelocytic Leukemia

The immunophenotype of 72 cases with acute myelocytic leukemia was investigated with a panel of monoclonal antibodies. When the morphologic criteria of the FAB classification was compared with the normal myeloid and erythroid pathway of differentiation identified by MoAbs, a relationship was found with FAB M5 and M6. Moreover, a constant negativity to HLA-DR and CD15 antigens in M3 and the contemporaneous expression of HLA-DR and CD11b antigens on the M4 and M5 leukemic cells were observed. We identified phenotypically distinct groups of patients with different responses to therapy. In fact, patients whose leukemic cells did not express the HLA-DR antigen showed, in a univariate analysis, a significantly higher percentage of complete remissions than did HLA-DR-positive patients. Multivariate discriminant analysis, in line with this result, showed that the parameters of discriminant capacity were, in order of statistical significance, young age, low WBC count and the lack of DR expression, respectively. A trend for a better response to therapy, without any statistical relevance, was also observed in CD11b-negative and CD33-positive cases. Similar results were detected In patients who expressed either DR or CD11b, or none of these markers. These findings indicate that immunophenotype may identify some FAB subtypes. Moreover, in some cases the phenotypic profile can provide useful information about the clinical outcome.

Intravenous immunoglobulin treatment responsiveness depends on the degree of CD8+ T cell activation in Kawasaki disease

Kawasaki disease (KD) has become the most common cause of acquired heart disease in children and is also a risk factor for ischemic heart disease in adults. However, Kawasaki disease lacks specific laboratory diagnostic indices. Thus, this study analyzed the T cell activation profiles of Kawasaki disease and assessed their value in the diagnosis of Kawasaki disease and the prediction of intravenous immunoglobulin (IVIG) sensitivity. We analyzed human leukocyte antigen-DR (HLA-DR), CD69 and CD25 expression on peripheral blood CD4+ and CD8+ T cells during the acute phase of KD. We compared the percentages of HLA-DR+/CD69+/CD25+ T cells in the CD4+ and CD8+ T cell populations of IVIG-effective and IVIG-resistant groups. Receiver operating characteristic curves were used to assess the diagnostic value of the above parameters. The median percentage of CD8+HLA-DR+ T cells and the median ratio of CD8+HLA-DR+ T cells/CD8+CD25+ T cells were significantly elevated in the patient group compared with those in the control group during the acute phase of KD. Regarding the diagnosis of Kawasaki disease, the area under the ROC curve was 0.939 for the percentage of CD8+HLA-DR+ T cells. There was a significant difference in the ratio of CD8+HLA-DR+ T cells/CD8+CD69+ T cells between IVIG-resistant patients and IVIG-sensitive patients. Regarding IVIG sensitivity, the area under the ROC curve was 0.795 for it. Excessive CD8+ T cell activation, as well as an imbalance between CD8+ T cell activation and inhibition, underlies the pathogenesis of Kawasaki disease. The percentage of CD8+ HLA-DR+ T cells may be used as an index to diagnose Kawasaki disease. IVIG inhibits CD8+ T cell activation, but excessive CD8+ T cell activation may cause IVIG resistance. The ratio of CD8+HLA-DR+ T cells/CD8+CD69+ T cells may be used as a predictor of IVIG sensitivity.

Relationship between T-cell HLA-DR expression and intravenous immunoglobulin treatment response in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is an acute febrile illness associated with the development of vasculitis. Administration of intravenous immunoglobulin (IVIG) is the standard treatment for KD. However, IVIG treatment is not effective in approximately 15% of children with KD. Some reports have presented evidence of immunological responses in IVIG-resistant KD patients. We assessed the possibility that T-cell activation is a contributing mechanism underlying this phenomenon.

METHODS

We analyzed human leukocyte antigen-DR (HLA-DR) expression on peripheral blood CD4+ and CD8+ T cells in 82 children with KD who were admitted to the hospital between October 2007 and February 2012. We compared the percentages of HLA-DR+ T cells among the CD4+ T-cell and CD8+ T-cell populations for the IVIG-effective and IVIG-resistant groups.

RESULTS

Among the 82 subjects, 51 had IVIG-effective KD and 31 children had IVIG-resistant KD. The percentages of HLA-DR+ T cells among the CD4+ T-cell and CD8+ T-cell populations in the IVIG-effective group were significantly lower than those in the IVIG-resistant group.

CONCLUSION

Our results suggest that increased T-cell HLA-DR expression is associated with IVIG resistance in KD patients, indicating that HLA-DR expression would be a useful tool for predicting IVIG responsiveness during KD pathogenesis.

An ordered sequence of expression of human MHC class-II antigens during B-cell maturation?

Studies with monoclonal antibodies confirm that human MHC class-II antigens are encoded by at least three pairs of loci. Here Keith Guy and Veronica van Heyningen suggest that as B cells mature theproducts of these loci are expressed in the sequence SB → DR → DC antigens - a sequence which parallels the order of the genes on chromosome 6.

Extensive FDG uptake and its modification with corticosteroid in a granuloma rat model: an experimental study for differentiating granuloma from tumors

INTRODUCTION

Increased (18)F-fluorodeoxyglucose (FDG) uptake in inflammatory lesions, particularly in granulomatous inflammation (e.g., sarcoidosis), makes it difficult to differentiate malignant tumors from benign lesions and is the main source of false-positive FDG-PET findings in oncology. Here, we developed a rat granuloma model and examined FDG uptake in the granuloma. The effects of corticosteroid on FDG uptake in the granuloma were compared with those in a malignant tumor.

METHODS

Rats were inoculated with Mycobacterium bovis bacillus Calmette-Guérin (BCG) or allogenic hepatoma cells, and subdivided into control and pretreated (methylprednisolone acetate, 8 mg/kg i.m.) groups. Radioactivity in tissues was determined 1 h after the FDG injection. FDG-PET was performed in rats bearing BCG granulomas or tumors before and after prednisolone treatment.

RESULTS

Mature epithelioid cell granuloma-formation and massive lymphocyte-infiltration were observed in the control group of granuloma, histologically similar to sarcoidosis. The mean FDG uptake in the granuloma was comparable to that in the hepatoma. Prednisolone reduced epithelioid cell granuloma-formation and lymphocyte-infiltration. Prednisolone significantly decreased the level of FDG uptake in the granuloma (52% of control), but not in the hepatoma. The FDG uptake levels in the granulomas and tumors were clearly imaged with PET.

CONCLUSION

We developed an intramuscular granuloma rat model that showed a high FDG uptake comparable to that of the tumor. The effect of prednisolone pretreatment on FDG uptake was greater in the granuloma than in the tumor. These results suggest that BCG-induced granuloma may be a valuable model and may provide a biological basis for FDG studies.

Cross-linking of MHC class II molecules interferes with phorbol 12,13-dibutyrate-induced differentiation of resting B cells by inhibiting Rac-associated ROS-dependent ERK/p38 MAP kinase pathways leading to NF-kappaB activation

In addition to their essential role in antigen presentation, major histocompatibility complex (MHC) class II molecules have been described as the receptor associated with signal transduction regulating B-cell function. In previous experiments, we found that cross-linking of MHC class II molecules with corresponding anti-MHC class II antibodies inhibited NF-kappaB-activated signaling pathways associated with the proliferation and differentiation of the LPS-stimulated primary and resting B-cell line, 38B9. We also found that exposure to the anti-MHC class II antibody reduced the production of ROS, which function as secondary signal transducers, in the phorbol 12,13-dibutyrate (PDBU)-treated (but not in the LPS-treated) resting B-cell line. In this study, we investigated the molecular mechanisms in the ROS-associated signaling pathway leading to PDBU-induced NF-kappaB activation that results in B-cell differentiation and speculated that the signaling pathway was inhibited by exposure to the anti-MHC class II antibody. We also found that this inhibition was mediated through down-regulation of the activated Rac/ROS-associated ERK/p38 MAPK signaling pathway in PDBU-treated 38B9 cells. Collectively, these findings suggest that ROS-associated molecules are involved in MHC class II-associated negative signal transduction in resting B cells.

The expression of human leukocyte antigen-DR and CD25 on circulating T cells in cutaneous lupus erythematosus and correlation with disease activity

BACKGROUND

Lupus erythematosus (LE) is a chronic autoimmune disease with a broad clinical spectrum reaching from primarily cutaneous manifestations [cutaneous LE (CLE)] up to systemic disease [systemic LE (SLE)]. In patients with SLE, the expression of activation markers on circulating T cells reflects disease activity. Here, we investigated whether this also holds true for patients with CLE.

PATIENTS AND METHODS

The expression of the activation markers human leukocyte antigen (HLA)-DR and CD25 on circulating T lymphocytes was measured by flow cytometry in 24 patients suffering from different types of active CLE. Simultaneously, the disease activity was assessed clinically using a CLE activity index. Eighteen healthy donors were analyzed for control purposes.

RESULTS

HLA-DR was expressed on a significantly elevated percentage of both CD4+ and CD8+ circulating T cells in active CLE patients when compared with healthy controls. The percentage of HLA-DR-expressing T lymphocytes closely correlated with the disease activity. Interestingly, in disseminated scarring chronic discoid LE, a significantly increased percentage of CD25+ cells was observed only in the subset of skin-homing cutaneous lymphocyte antigen (CLA)+CD4+ and CD8+ T cells.

CONCLUSION

Our results provide evidence that activation markers on peripheral blood T cells might help to objectively assess the disease activity in CLE. Furthermore, a significant population of CD25+CLA+CD8+ T cells can only be detected in a subgroup of patients with disseminated scarring CLE and might reflect the systemic expansion of activated cytotoxic T lymphocytes involved in destruction of epidermal tissue.

The genetics of autoimmune-mediated rheumatic diseases: clinical and biologic implications

This article emphasizes the interpretation of the meaning and significance of the genetic aspects of susceptibility to certain autoimmune-mediated rheumatic diseases. The familial aggregation and identical twin concordance that provides the basis of considering these as genetic diseases are reviewed. Major histocompatibility complex (MHC) genes are taken as the primary examples of candidate genes that regulate the immune response; the potential function of these genes in predisposing to autoimmune diseases is analyzed. Autoimmune diseases are discussed as the consequence of the role of MHC molecules encoded by different alleles that exhibit distinct peptide-binding properties and select a self reactive T-cell repertoire. The low penetrance rates of autoimmune-mediated rheumatic disease is used as an argument that stochastic events in the generation and postthymic maturation of the somatically expressed T-cell repertoire account for the characteristically delayed onset of these diseases. The importance of self-reactivity in the physiologic immune response is used as an argument that the events that are responsible for the development of an autoimmune disease are an untoward exaggeration of normal immune responsiveness, but not a qualitatively distinct biologic event.

HLA-DR expression on lymphocyte subsets as a marker of disease activity in patients with systemic lupus erythematosus

A major problem in the management of SLE patients is to predict a flare or to distinguish between active and quiescent disease. Serological markers are widely used to assess disease activity, but many patients have close to or normal values for these parameters while exhibiting obvious disease-related signs and symptoms. This study aimed to determine which serological parameters, among ESR, ANA and anti-dsDNA antibody titres, CH50 and the HLA-DR expression on circulating T-lymphocyte subsets, best reflected the development of SLE flares. Sixty SLE patients were included, 34 with quiescent disease throughout the entire follow-up period and 26 who experienced an SLE flare defined as having active disease. According to univariate analysis, all parameters were significantly higher for patients with active disease, with the percentage of CD8+DR+ cells being the most significant parameter (P = 10-7). Multivariate logistic regression analysis identified three independent variables enabling the identification of a lupus flare: CH50, the CD8+DR+ and CD4+DR+ cell percentages among total lymphocytes. The CD8+DR+ cell percentage is the biological parameter most significantly associated with a flare (P < 0.001), even more powerful than CH50 (P < 0.01). HLA-DR expression on CD8+ lymphocytes clearly coincided with disease evolution in seven patients enrolled as having quiescent disease, but who experienced one flare during follow-up that subsequently resolved. The percentage of circulating CD8+DR+ lymphocytes appears to be a biological marker which accurately reflects disease activity. A larger prospective study is needed to demonstrate the real efficacy of this marker in predicting an exacerbation in SLE patients.

Human leukocyte antigen II expression in sperm cells: comparison between fertile and infertile men

Human leukocyte antigens (HLA) class II transcripts in mature spermatozoa of healthy volunteers have recently been demonstrated using reverse transcription polymerase chain reaction (RT-PCR). HLA II expression was investigated on ejaculated sperm cells in fertile and infertile men by RT-PCR and flow cytometry. Among 22 fertile and 20 infertile men, 18 were selected for the study because they showed no contamination with non-sperm cells. HLA II mRNA transcripts were expressed in all but 1 of 8 infertile subjects and in only 2 of 10 fertile ones. The cytofluorometric analysis on three RT-PCR positive samples confirmed the presence of class II antigens on cell surfaces. These data clearly confirm the presence of both HLA II mRNA and surface molecules on human sperm cells. In addition, an interesting nonrandom distribution of positivity among fertile and infertile samples regarding HLA II expression (p < .025) suggests a possible correlation with infertility.

Biological implications of HLA-DR expression in tumours

HLA-DR antigens show restricted tissue distribution in comparison with the more extensive expression of HLA class I molecules. This constitutive expression is genetically controlled by well-defined mechanisms. In addition, DR antigen expression can be induced by a variety of cytokines through different molecular genetic events that convert DR-negative epithelia into positive cells. In this review we analyse the two major pathological situations in which abnormal DR expression occurs: autoimmune diseases and tumour development. We hypothesize that conversion to DR-positivity may produce two opposite effects in both clinical situations: (1) a useful one in tumours associated with a good prognosis; and (2) a harmful one in autoimmune diseases with increased tissue damage.

Relationship between frequent episodes of peritonitis and altered immune status

A 60-year-old Native American diabetic female patient had a history of nine episodes of peritonitis (both relapsing and persistent) during the year that she was treated with continuous ambulatory peritoneal dialysis (CAPD). At the start of CAPD the patient had an inverted CD4 to CD8 ratio that decreased from 0.97 to 0.50 in 1 year. This finding was due to a decrease in CD4+ cells and an increase in CD8+ cells that were also positive for CD57 (Leu-7) and HLA-DR (Ia) antigen, suggesting a state of activation. The serology indicated a cytomegalovirus immunoglobulin G titer of 1:2,048. The patient also had significantly increased natural killer cells. These alterations suggest the presence of a chronic viral infection that may have caused the patient to be immunosuppressed, thereby predisposing her to repeated episodes of peritonitis.

Reduced activation of suppressor T lymphocytes by specific antigens in autoimmune thyroid disease

In order to study the activation of suppressor T lymphocytes by thyroid-specific antigens in autoimmune thyroid disease (AITD), we have investigated the effects of the organ-specific antigens, thyroperoxidase (TPO), thyroglobulin (Tg), and thyroid microsomal antigen (TMc), as well as renal microsomes (RMc) as a control antigen, on the activation of suppressor T lymphocytes; this was accomplished by measuring major histocompatibility complex class II (HLA-DR) expression on their surfaces by flow cytometric analysis. Peripheral blood mononuclear cells (PBMC), obtained from 33 patients with Graves' disease (GD), 26 with Hashimoto's thyroiditis (HT), 5 with nontoxic nodular goiter (NTG), and 30 normal persons (N), were cultured for 7 days in the presence or absence of TPO, Tg, or RMc at final concentration of 10, 100, and 1000 ng/ml. Cultured cells were stained with fluorescent-conjugated monoclonal antibodies (anti-CD8, anti-CD11b, and anti-HLA-DR), and the activation of CD8+ and CD8+CD11b+ (pure suppressor) T cells by the antigens was analyzed on a flow cytometer. In the absence of antigen, i.e., the autologous mixed lymphocyte reaction (AMLR), CD8+ and CD8+CD11b+ T lymphocytes from patients with GD and HT showed significantly lower activation as compared to N. We measured the Stimulation Index (Sl) of activated T lymphocytes to compare antigen-specific activation between CD8+ and CD8+CD11b+ cells from normal persons and patients. With stimulation of 100 and/or 1000 ng/mL of TPO or Tg, Sl of activated CD8+ cells was significantly (p < 0.05 to 0.01) lower in GD and HT as compared with N.(ABSTRACT TRUNCATED AT 250 WORDS)

Major histocompatibility complex and human papillomavirus type 16 E7 expression in high-grade vulvar lesions

To determine whether expression of the human papillomavirus (HPV) type 16 E7 open reading frame influences expression of major histocompatibility complex (MHC) antigens on the surface of squamous epithelial cells, serial frozen sections from seven HPV type 16-positive, high-grade vulvar intraepithelial neoplasia (VIN 2-3) lesions were tested for viral transcription by RNA-RNA in situ hybridization, for MHC expression by immunohistochemical staining with antibodies to MHC class I and II molecules, and for keratinocyte differentiation by immunohistochemical staining with anti-filaggrin and cytokeratin 10 antibodies. Despite the histologic appearance of high-grade VIN lesions, expression patterns of cytokeratin 10 and filaggrin suggested a certain degree of keratinocyte differentiation in all specimens. These differentiation markers were especially prominent in parakeratotic and hyperkeratotic superficial areas, which did not express MHC antigens or contain E7 mRNA. Expression of MHC class I molecules within dysplastic tissues was greater than within HPV type 16-negative, normal vulvar epithelium from the same patients. In five of the VIN 2-3 specimens anti-MHC class I antibodies reacted more strongly with cells of the basal and suprabasal layers than with cells of the epithelial surface. In one lesion basal cells stained less intensively than surface cells, whereas in another specimen all epithelial layers were equally MHC class I positive. Staining with anti-MHC class II antibodies was generally restricted to isolated foci, representing invading lymphocytes, tissue macrophages, and Langerhans cells. In two lesions, however, there was heterogeneous keratinocyte expression of MHC class II proteins, perhaps due to inflammation. Major histocompatibility complex antigen detection was independent of the presence or distribution pattern of E7-specific transcripts. Hence, a correlation between MHC and E7 expression appears unlikely in warty VIN lesions.

Immunophenotypic analysis of extranodal non-Hodgkin's lymphomas in the oral cavity

Fifty cases of extranodal non-Hodgkin's lymphoma arising in the oral cavity were reclassified using the updated Kiel classification. In order to determine the antigenic phenotype of the proliferating cells in oral lymphoma, we used a panel of paraffin effective antibodies that are known to react with lymphocyte- and histiocyte-associated antigens. The median age of the patients was 53 years, with a male predominance (M:F = 1.9: 1). The great majority of oral non-Hodgkin's lymphomas were B-cell lymphomas. There were 12 low-grade B-cell lymphomas (comprising one mucosa-associated lymphoid tissue, four centrocytic and seven centroblastic-centrocytic lymphomas) and 25 high-grade tumors (comprising 17 centroblastic, two immunoblastic, two Burkitt's and four lymphoblastic lymphomas). All 37 B-cell malignancies showed reactivity for L 26 and KiB 3. A monotypic immunoglobulin staining pattern, as revealed by light chain restriction, was found in 21 cases (57%) of the non-Hodgkin's lymphomas confirming their B-cell origin. Furthermore, monotypic staining for kappa-chain predominated (16/21 kappa, 5/21 lambda). Only a small number (6 cases) was of T-cell lineage and all cases showed positive reaction for UCHL 1, MT 1 and DFT 1. In one of six T-cell lymphomas, Ber-H 2 positive anaplastic large cell lymphoma was detected. Such a case was documented for the first time in the primary extranodal non-Hodgkin's lymphoma of the oral cavity. Five cases could be assigned with certainty to the histiocytic system. These cases were positive for cathepsin D and KP 1 LN 3, which recognized Ia (HLA-DR) antigens, was demonstrated most frequently in high-grade B-cell lymphomas, T-cell lymphomas and true histiocytic lymphomas.

Seasonal variation and sex differences of circulating macrophages, immunoglobulins and lymphocytes in healthy school children

Subpopulations of T and B lymphocytes and levels of serum immunoglobulins G, A, M, E and subclasses G1, G2 and G3 were studied in 45 healthy school children aged 8-16 years during four seasons of the year. There were significant increases in CD4+ T helper cells, total T lymphocytes and CD4+/CD8+ (helper/cytotoxic) T-cell ratio during the spring season. While the levels of CD8+ T cells and total B lymphocytes remained statistically unchanged during all four seasons, the levels of natural (HNK-1) killer cells and macrophages increased significantly during the autumn and summer seasons respectively. The levels of immunoglobulins G, A, M and E remained statistically unchanged during all four seasons. Girls had higher levels of CD4+ T cells and a higher CD4+/CD8+ T-cell ratio than boys. Girls also had slightly higher levels of immunoglobulin G and M. These observations suggest that seasonal variations of some immunological parameters occur in healthy children. This may be an adaptive response to variable climatic and other environmental factors. These natural variations due to seasonal changes should be taken into account when immunological tests are used in clinical investigations.

Interleukin 2 therapy: current role in surgical oncological practice

The use of recombinant interleukin 2 (rIL-2) in clinical practice has opened up new and beneficial avenues in the treatment of certain malignant diseases. Although rIL-2 can stimulate a range of host antitumour defence mechanisms, only 30-40 per cent of patients who are treated will respond to such therapy as assessed by a reduction in tumour volume. The effect of rIL-2-based treatment schedules on delaying progression of disease and on overall survival in comparison with standard current treatments and chemotherapeutic regimens is not clear. Randomized clinical trials are required to evaluate precisely the role of rIL-2 in various therapeutic combinations and to ascertain the optimum therapeutic regimens for individual tumour types. Studies currently under way should provide more insight into the possible beneficial effects of immunotherapy with rIL-2. More basic research is required to ascertain how rIL-2 may produce its antitumour effects and why the therapeutic results obtained in humans have been so selective and less beneficial than those in experimental animals.

Suppression of murine collagen-induced arthritis by treatment with a novel thiazole derivative, SM-8849

The antiarthritic activity of a novel thiazole derivative, SM-8849, was compared with that of indomethacin and D-penicillamine, in mice with collagen-induced arthritis. SM-8849 reduced the incidence and severity of disease in collagen-immunized mice, as assessed by clinical observation. This efficacy was also confirmed by radiographic and histologic studies. Indomethacin produced an apparent reduction of the clinical score, but had only a marginal effect on bone destruction. D-penicillamine did not produce any improvement. Unlike indomethacin and D-penicillamine, SM-8849 reduced the serum levels of anti-type II collagen antibodies. Flow cytometric analysis of spleen cells from arthritic mice revealed an increase in T cells expressing activation antigens (class II antigens) in comparison with normal mice. Treatment with SM-8849, but not indomethacin or D-penicillamine, prevented the increase in Ia-bearing T cells. The results suggest that an effect of SM-8849 on immunocompetent cells may be responsible for the antiarthritic activity of the compound, and this would distinguish its action from that of traditional antirheumatic drugs.

Immunophenotype of multinucleated and mononuclear cells in giant cell lesions of bone and soft tissue

AIMS

To compare the antigenic phenotype of giant cells in giant cell lesions of bone and soft tissue with that of osteoclasts and macrophage polykaryons.

METHODS

Formalin fixed, paraffin wax embedded sections of 106 giant cell lesions, 19 granulomatous, and 14 osteoclast containing lesions were immuno-histochemically stained for leucocyte common antigen (LCA), CD68, and HLA-DR.

RESULTS

Osteoclasts and giant cells of giant cell tumour of bone and giant cell reparative granuloma could be distinguished by their generalised absence of HLA-DR reaction from macrophage polykaryons and giant cells in other giant cell lesions of bone and soft tissue. Staining for LCA, CD68, and HLA-DR was useful in distinguishing reactive histiocytic giant cells and osteoclasts from tumour giant cells.

CONCLUSIONS

A panel of macrophage associated antigens should be diagnostically useful in differentiating the histological nature of giant cells in various giant cell lesions of bone and soft tissue.

T-cell chronic lymphocytic leukemia. T-cell function and lymphokine secretion

The leukemic T-cells of the six patients with T-cell chronic lymphocytic leukemia (T-CLL), four with CD4 and CD45R-positive (CD4+ CD45R*) T-CLL and two with CD8 and CD45R-positive (CD8+ CD45R+) T-CLL phenotype were studied for detailed immunologic phenotypic and functional characteristics. The levels of soluble interleukin-2 receptors were elevated significantly in the serum of all four patients with CD4+ CD45R+ T-CLL. Moreover, the CD4+ CD45R+ T-CLL patients' T-cells, after in vitro stimulation with phytohemagglutinin and concanavalin A, expressed elevated percentages of interleukin-2 receptors on cells and secreted high interleukin-2 activity. The B-cell growth factor (BCGF) activity from three patients with CD4+ CD45R+ T-CLL was enhanced, but B-cell differentiation factor (BCDF) activity of the all T-CLL patients was decreased. Reduced BCGF and BCDF activity of the leukemic T-cells was one possible mechanism of hypogammaglobulinemia detected in two patients with T-CLL. All T-CLL patients' leukemic T-cells had diminished immunoregulatory functional activity in allogeneic mixed lymphocyte reactions. These observations suggest that leukemic T-cells from T-CLL patients have many immunologic functional defects that may be important in their proliferative potential.

Cytokines in proliferative vitreoretinopathy

This study determined the presence of interleukin 1 (IL-1), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF alpha), tumour necrosis factor beta (TNF beta), interferon gamma (IFN gamma), transforming growth factor beta 2 (TGF beta 2) and fibroblast proliferation activity (FPA) in vitreous aspirates from eyes undergoing vitrectomy for the treatment of retinal detachment complicated by proliferative vitreoretinopathy (PVR) or uncomplicated retinal detachment (RD). Cadaveric vitreous from normal subjects were used as controls. The results showed that IL-1 and IL-6 predominated in vitreous from eyes with PVR or RD, and that concentrations of IL-6 greater than 20 pg/ml were more frequently found in PVR than in RD (p = 0.031) or control specimens (p = 0.006). Low levels of TNF alpha were observed in 4/18 eyes with PVR, 1/15 eyes with RD and 1/15 control vitreous, and small concentrations of TNF alpha were seen in 3/18 eyes with PVR, 1/15 eyes with RD and 2/15 control vitreous. IFN gamma was detected in 12/18 eyes with PVR, but only in 5/15 eyes with RD (p = 0.048) and 6/15 control specimens. TGF beta 2 was present in all vitreous samples at concentrations ranging from 100 to 4,500 pg/ml with no significant differences among the three groups. Control vitreous possessed the greatest FPA when compared with vitreous from eyes with PVR (p = 0.031) or RD (p = 0.048). These observations provide further evidence that cytokine-mediated pathways of inflammation are involved in the pathogenesis of PVR and point to the possible involvement of IL-1, IL-6 and IFN gamma in cellular interactions leading to chronicity.

Activated T lymphocyte subsets in experimental allergic neuritis

Changes in activated T cell subsets in peripheral blood were examined during the course of experimental allergic neuritis (EAN), using two-color immunofluorescence flow cytometry. Both CD4+ and CD8+ activated T cells decreased transiently before the onset of clinical signs, and increased just around the time of onset of the disease. In contrast, during the recovery phase, the numbers of CD4+ activated T cells returned to the normal range, whereas CD8+ activated T cells continued to increase. These findings imply that activation of CD4+ helper/inducer cells contributes mainly to the evolution of EAN, and that of CD8+ suppressor cells are necessary for recovery.

Natural killer cells and lymphocyte subsets in active MS and acute inflammation of the CNS

Cerebrospinal fluid (CSF) and peripheral blood (PB) lymphocyte subsets were determined by flow cytometry (FCM) in 15 patients with active multiple sclerosis (MS) and 15 patients with acute inflammatory diseases (ID) of the central nervous system (CNS) in order to establish correlations between the two groups of diseases, as well as between the CSF and PB subsets distribution. A panel of monoclonal antibodies was applied to all the samples: Leu3 (CD4), Leu4 (CD3), Leu2 (CD8), Anti-HLA-DR, Leu11 (CD16). Statistical analysis did not show differences in CD3+ nor in CD3+ DR+ T-cells both in the CSF and PB in the two groups of patients. CD4+ cells were significantly higher in the CSF than in the PB, while CD8+, DR+ CD3- and CD16+ cells were constantly lower in the CSF without differences between the two groups of diseases.

Bacterial meningitis: T cell activation and immunoregulatory CD4+ T cell subset alteration

Meningitis is the most important cause of acquired postnatal deafness and neurologic disorders in children. To determine if cell-mediated immunity is casually related to the pathogenesis of bacterial meningitis, T cell subsets were quantitated from blood of the 29 children with clinical and bacteriologic diagnosis of Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis bacterial meningitis. The CD4+ T cells increased and CD8+ T cells decreased in patients with meningitis as compared to patient control subjects (bacterial infections without meningitis) and normal healthy control subjects. An elevated percentage of CD25+ (interleukin-2 receptors) and HLA-DR+ (immune-response gene-associated antigen) T cells were detected from all patients with meningitis. All 29 patients with meningitis had highly elevated CD4+ CD45R+ (suppressor-inducer) cells and reciprocally depressed CD4+ CDw29+ (helper-inducer) cells compared with healthy age-matched normal and patient control subjects. These findings indicate characteristic immunologic T cell abnormalities from meningitis. The abnormal increase in the CD4+ CD45R+ suppressor-inducer or "virgin" cells and expression of activation antigens on T cells may be of help in future understanding of abnormal immune reactions from bacterial meningitis. However, deficiency of the CD4+ CDw29+ helper-inducer or "memory" cells may contribute to the impaired helper function for B cell-induced protective antibody synthesis to bacterial capsular polysaccharides found in this disease.

Genetically determined coincidence of Kaposi sarcoma and psoriasis in an HIV-negative patient after prednisolone treatment. Spontaneous regression 8 months after discontinuing therapy

We report the case of drug-induced, acrolocalized Kaposi sarcoma (KS), arising multicentrically in both palms and soles of a male patient who has had widespread psoriasis since 12 years of age. This 59-year-old man, of Mediterranean origin, was HIV antibody-negative and had received oral prednisolone treatment over 5 months for chronic obstructive lung disease (initial dose: 75 mg/d). Eight months after discontinuing oral treatment the KS nodules regressed spontaneously and finally disappeared completely without additional treatment. Light and electron microscopic investigations confirmed the diagnosis of KS, whereas laboratory tests excluded HIV infection and suggested mild immune dysfunction. The existence of HLA loci predisposing to KS and to psoriasis (A1, DR5, DR7, DR11) was characteristic for the simultaneous occurrence of these two diseases. This case report demonstrates the complex interrelationships between genetic predisposition, drugs leading to immune suppression, and the evolution of an unusual neoplasm.

The cell biology of antigen processing

T lymphocytes recognize antigen only after a series of intracellular events known as antigen processing. The result of antigen processing is the production of short segments of the primary peptide sequence bound to a polypeptide-binding groove on major histocompatibility complex (MHC) molecules. Antigen originates from one of two sites: intracellular or extracellular. There are two corresponding pathways for antigen processing and two corresponding classes of MHC molecule. Analysis of each pathway has demonstrated that their separation is not purely anatomical, but is maintained by molecular interactions with other molecules. Antigen processing has been shown to regulate the overall immune response, but the mechanisms involved remain obscure.

Neurobiology of human oligodendrocytes in culture

Enriched populations of oligodendrocytes were isolated from adult human brains of 3-15 hours postmortem using the trypsinin digestion-Percoll density gradient method and were cultured for an extended period of time up to 6 months. Cell type specific antigens that were expressed by oligodendrocytes were galactocerebroside, myelin basic protein, proteolipid protein, 2'3'-cyclic nucleotide 3'-phosphohydrolase and myelin-associated glycoprotein. In addition, HLA-A,B,C and HLA-DR, respectively, Class I and Class II antigens of the major histocompatibility complex, were demonstrated on oligodendrocytes. Three classes of gangliosides, GM1, GM4, and GD3, were also demonstrated on oligodendrocytes, while GM1 and GM4 gangliosides were detected on the surface of astrocytes. The presence of "transitional" or "bipotential" glial cells that were derived from oligodendrocytes and that expressed both oligodendroglial and astrocytic phenotypes was demonstrated. Treatment of the cells by cyclic AMP and its derivatives reversed this dual phenotypic expression back to the oligodendroglial trait. Electron microscopic examination of oligodendrocytes indicated that they were capable of synthesizing and assembling myelin sheaths in culture in the absence of any neuronal signal input.

Bacillus Calmette-Guérin-treated superficial bladder cancer: correlation of morphology with immunophenotyping

Thirty-five biopsies from 19 patients with superficial transitional cell carcinoma of the bladder, treated with intravesical bacillus Calmette-Guérin (BCG), were assessed histologically and immunohistochemically. Pretreatment biopsies were available for comparison in all cases and five cases of non-specific cystitis were also examined. The inflammatory infiltrate was assessed with a streptavidin-biotin-peroxidase method using UCHL1, MT1, LN3, L26, HAM56, MAC387, Leu7 and anti-S100 in paraffin sections, and in 18 specimens were frozen tissues were available, Leu1, 2, 3, 4, 14, OKT10, HLA-DR and anti-Tac antibodies were applied. Post-treatment bladder biopsies showed severe oedema and a variable degree of inflammation. A granulomatous inflammation was seen in 11 cases, with granulomas present in six prostatic biopsies and acid-fast bacilli in two cases. The lymphoid infiltrate in all biopsies were largely T lymphocytes with a predominance of T helper cells present, often as a band-like infiltrate pressing against the residual epithelium, or the denuded bladder surface, and distributed in the vicinity of the granulomas. Activated lymphocytes were prominent in seven cases, although a moderate infiltrate of such cells was seen in all instances. Tac antigen was only occasionally expressed, and in a few NK cells were present among the infiltrates. In eight cases, HLA-DR was expressed in epithelial cells following BCG treatment, whereas all pre-treatment epithelial were negative.

Analysis of lymphocyte subsets of bone marrow in patients with rheumatoid arthritis by two colour immunofluorescence and flow cytometry

Lymphocyte subsets defined by monoclonal antibodies were investigated in bone marrow and peripheral blood of 17 patients with rheumatoid arthritis (RA); 13 patients with osteoarthritis or aseptic necrosis served as controls. Patients with RA were found to have a raised OKT 4/8 ratio both in bone marrow and peripheral blood in comparison with the controls. Furthermore, bone marrow of RA showed a lower percentage of OKT 8+ T cells than that of controls. The percentage of HLA-DR+ T cells was higher in bone marrow than in peripheral blood of RA, though a slightly lower percentage was detected in bone marrow than in peripheral blood of controls. Thus T cell subsets in bone marrow of RA differ significantly from those of controls. Patients with RA had a higher OKT 4/8 ratio and a higher percentage of HLA-DR+ T cells in bone marrow than controls, suggesting that T cell subsets in bone marrow of RA are in an immunologically activated state and that T cell subsets are affected by rheumatoid inflammation in bone marrow of RA.

Activated CD4-positive T-lymphocytes and impaired cell-mediated immunity in patients with carcinoma of the urinary bladder with schistosomiasis

Patients with schistosomiasis of the urinary bladder (SB) associated with carcinoma of the bladder (SCB) or carcinoma of the prostate (SCP) have a variety of immunologic abnormalities, including the presence of HLA-DR+ and interleukin-2 receptor-positive (IL-2R+) T-lymphocytes in circulating blood. This study demonstrated that, the HLA-DR+ and IL-2R+ antigens are selectively expressed on majority of the CD4+ T-lymphocytes of patients with SCB, whereas, these antigens are expressed almost equally on both CD4+ and CD8+ T-lymphocytes of patients with SB and SCP. Expressions of HLA-DR+ and IL-2R+ antigens in CD4+ T-lymphocytes, and a depressed response of this T-cell subset to phytohemagglutinin and Concanavalin A stimulations seems to be the characteristic feature of these patients with SCB. In addition, the autologous mixed lymphocyte reaction (AMLR) and allogenic mixed lymphocyte reaction (MLR) was depressed in patients with SCB. However, patients with SCP demonstrated a normal MLR, even though the AMLR was highly depressed. The immunoregulatory role of the HLA-DR+, IL-2R+, CD4+ helper/inducer T-lymphocytes, and the AMLR and MLR abnormalities we have identified in patients with SCB may be important and could play a role in the pathobiology of these diseases in humans.

The definition of five B lymphocyte alloantigens closely linked to BoLA class I antigens

B lymphocyte alloantigens in cattle were identified by serological analysis. Alloantisera were raised by skin implant immunization or leucocyte immunization and were absorbed with platelets to reduce class I-specific antibody activity. Leucocyte absorptions were done to reduce the complexity of some antisera. A panning technique was used to prepare B-enriched and B-depleted lymphocytes. Antisera which displayed anti-B cell activity over a number of dilutions were tested against 115 Charolais cattle, and 13 antisera were used to define five B lymphocyte alloantigens. These antigens were present on B lymphocytes but did not appear to be present, at least at the same density, on the majority of T lymphocytes or platelets. Family studies suggested that these antigens are coded by one or two loci which are closely linked to the bovine class I loci. These results suggest the five antigens are class II antigens of the major histocompatibility complex (MHC) of cattle.

Increased circulating HLA-DR+ CD4+ T cells in systemic lupus erythematosus: alterations associated with prednisolone therapy

Patients with active systemic lupus erythematosus (SLE) in the circulation have a selective increase of a subset of the CD4+ helper/inducer T cells bearing HLA-DR+, major histocompatibility complex class II antigens. We studied prednisolone-induced alterations of HLA-DR+, CD4+, and CD8+ T-cell subsets in three patients with active SLE. Prednisolone therapy was accompanied by a drastic reduction in circulating HLA-DR+, CD4+ T-cell subsets, serum anti-DNA titre, normalization of the serum immunoglobulin profile, and CD4+ T-cell responses to phytohaemagglutinin and concanavalin A. These changes in immune functions were associated with eventual improvement in the clinical condition of active SLE. A low percentage of HLA-DR+, CD8+ T-cell subsets was present in the circulation, which was not changed by prednisolone therapy. These results suggest that HLA-DR+, CD4+ T-cell subsets play a major role in the pathogenesis of active SLE, and that prednisolone-induced immunosuppression in this disease is mediated by changes in the HLA-DR+, CD4+ T-cell subsets in circulating blood.

Induction of class II major histocompatibility complex antigen expression in human granulosa cells by interferon gamma: a potential mechanism contributing to autoimmune ovarian failure

We investigated the possibility that major histocompatibility complex (MHC) class II antigens and interferon gamma, a product of activated T lymphocytes, play a role in human autoimmune oophoritis. MHC class II molecules initiate immune responses by presenting antigens to T-helper lymphocytes; interferon gamma can induce class II antigen expression at ectopic sites and has been implicated in the cause of various autoimmune disorders. We studied the expression of class II MHC antigens in ovaries from normal women of reproductive-age and from women with premature autoimmune ovarian failure. Immunoperoxidase technique applied to tissue sections of nine normal human ovaries revealed class II MHC antigen expression only on occasional cells of macrophage morphology; granulosa cells were negative regardless of stage of follicular maturation. In contrast, extensive and intense class II antigen expression was observed in granulosa cells in ovarian biopsy sections from four patients with premature autoimmune ovarian failure. Immunofluorescence and radioimmunoassay techniques used to detect and quantitate MHC antigens revealed that class II antigen expression could be induced and class I MHC antigen expression was enhanced in granulosa cell cultures after the addition of interferon gamma. These data provide evidence that autoimmune oophoritis is associated with ectopic expression of MHC class II antigens by ovarian granulosa cells, and that this phenomenon can be induced by the immunologic cytokine interferon gamma.

A sensitive and specific ELISA using monoclonal capture antibodies for the detection of HLA antigens in blood stains

A double antibody ELISA technique is described to detect HLA antigens in extracts of blood stains. The assay involves capture of free HLA determinants using an immobilized monoclonal antibody directed against monomorphic regions of HLA class I and HLA class II antigens. The captured antigens are then detected using alloantisera directed against the polymorphic regions of the captured HLA entities. The technique is able to detect specific HLA-A, B, and DR antigens in extracts prepared from blood smears as well as from dried and freshly thawed lymphocytes. The assay may be of potential use in forensic medicine, particularly in instances where extraction of nucleic acids for fingerprinting is not feasible.

Proliferative vitreoretinopathy membranes. An immunohistochemical study

Proliferative vitreoretinopathy (PVR) is the leading cause of failure after retinal detachment surgery. Therefore, both the extracellular matrix and cellular components of preretinal membranes from 23 eyes with PVR were characterized immunohistochemically. The membrane stroma was composed primarily of types I, II, and III collagen. Laminin and both heparan sulfate proteoglycans and collagens types IV and V were co-distributed in discrete regions within the stroma. Glial and retinal pigment epithelial (RPE) cell populations were identified in these membranes using specific immunohistochemical markers as was a small but significant macrophage population. Double-labeling experiments indicated that RPE cells in these membranes expressed the class II histocompatibility antigen HLA-DR, although neither the RPE monolayer in situ nor cultured RPE cells was HLA-DR positive unless induced by gamma interferon. Only rare isolated vascular endothelial cells were detected in 5 of the 23 membranes.

Class I and class II HLA antigen expression by transitional cell carcinoma of the bladder: correlation with T-cell infiltration and BCG treatment

HLA class I and II glycoproteins from transitional cell carcinoma (TCC) and from perineoplastic and healthy vesical mucosa were characterized together with infiltrating cells by means of immunochemistry using specific monoclonal antibodies on frozen sections obtained during resection or radical cystectomy. Specimens were taken from 11 patients with TCC and five with healthy bladder mucosa. Four patients with TCC and four with healthy mucosa had been previously treated with a course of intravesical bacillus Calmette-Guerin (BCG). Ten out of 11 TCC samples expressed class I glycoproteins with a membrane pattern (diffuse in seven, focal in three) as normal epithelial cells from either controls or perineoplastic bladder. Interestingly, eight out of 11 TCC samples expressed class II antigens on their membrane that were also present in six cases in the perineoplastic tissue while the epithelial cells from four out of five normal bladders were completely negative. The epithelial display of class II antigens in the non-neoplastic areas and in the normal bladder correlates (p less than 0.001) with the degree of cellular infiltrate while such a relationship was not found between the HLA II expression of neoplastic cells and the infiltrate. BCG treatment was associated with a higher amount of inflammatory cells, prevalently T "activated" cells (CD5+,DR+), with a CD4/CD8 ratio always greater than 1. In the light of the role played by HLA glycoproteins in immune mechanisms, these results could help explain the positive action of BCG and the relative immunosensitivity of TCC.

In vitro phenotypic and functional characterization of human pigment epithelial cell lines

We have characterized human retinal pigment epithelium (HRPE) for the expression of cell surface antigens. Primary HRPE cultures, established cell lines, and freshly brushed pigment epithelial cells all express HLA-ABC but not HLA-DR antigens. However, both primary cultures and established cell lines can be induced by gamma interferon stimulation to express HLA-DR in a dose dependent manner. Only freshly brushed HRPE cells express Fc, and no cells demonstrated the presence of C3b. Our results show that HRPE cells change in culture, as reflected by the loss of Fc receptors, but retain the ability to synthesize HLA-ABC spontaneously and HLA-DR upon stimulation.

Peripheral nerve vasculitis: immune characterization of the vascular lesions

Quantitative immunohistochemical analyses were performed on 22 nerve biopsy specimens from patients with systemic vasculitis (n = 14) or isolated vasculitis of peripheral nerve (n = 8). In the vascular lesions the cellular infiltrates were composed primarily of T cells (71 +/- 18%; mean +/- SD) and macrophages (27 +/- 17%), and the majority of the T cells (65 +/- 20%) were cytotoxic/suppressor CD8 cells. B cells were seen in only 4 cases and constituted less than 2% of all cells. Natural killer cells and polymorphonuclear leukocytes were rare, and a leukocytoclastic response was not observed. Fourteen biopsy specimens had vascular deposits of immunoglobulins G and M and complement components C3 and C5b-9 membrane attack complex, while 4 had only the latter. The fact that the immunoglobulin and complement deposits were seen only in vessels that had corresponding intense cellular infiltrates suggests an important, but perhaps not primary, role for immune complexes in causing the vascular lesions. Statistical analysis revealed striking similarities in the lesions of patients with isolated nerve vasculitis and those with systemic vasculitides, suggesting a common pathogenic mechanism. Collectively, our observations suggest an important role for a T-cell-dependent cell-mediated process as a primary mechanism of vessel injury in peripheral nerve vasculitis.

The necessity of both allogeneic antigens and stem cells for cyclophosphamide-induced skin allograft tolerance in mice

We have reported that in an H-2 identical murine combination of AKR/J (AKR, H-2k, Thy1.1) and C3H/HeJ (C3H, H-2k, Thy 1.2), specific tolerance to C3H skin in AKR mice is induced only when both intravenously (i.v.) 1 x 10(8) viable C3H spleen cells and, two days later, intraperitoneally (i.p.) 200 mg/kg cyclophosphamide (CP) have been given. To further examine this mechanism of tolerance, we used 2000R-irradiated C3H spleen cells as an antigen source and bone marrow cells depleted of Thy1.2+ cells and Ia+ cells as a stem cell source. When a mixture of 1 x 10(8) irradiated spleen cells and 3 x 10(7) bone marrow cells was used as tolerogen and 200 mg/kg CP was administered two days later, a profound and specific long-lasting tolerance was induced. This tolerant state, however, was less profound than that induced with spleen cells plus CP. When the number of irradiated spleen cells was fixed at 1 x 10(8), the tolerant state was dose-dependent on the quantity of bone marrow cells. On the other hand, when the number of bone marrow cells was fixed at 1 x 10(6), tolerance induction depended on the dosage of irradiated spleen cells. Tolerance induced with irradiated spleen cells plus bone marrow cells and CP was tolerogen specific. Tolerance was never induced when the bone marrow cells had been irradiated with 2000R prior to injection. Transfer experiments showed that the tolerant state, in its acute phase, appeared to be predominantly based on reduction of functionally reactive cells. The prolongation of skin allograft survival in tolerant mice could not be attributed directly to suppressor cells, nor was any evidence of suppressive factor induction observed. In the chronic phase, however, the importance of the suppressive mechanisms appeared to be relatively increased. EPICS analysis of the thymocytes using fluorescein-conjugated anti-Thy1.1 and anti-Thy1.2 antibodies showed that a minimal degree of mixed chimerism had been established in the tolerant mice. Moreover, both T cells and Ia+ cells had beneficial effects on the induction of tolerance. We conclude that in the tolerance induced by spleen cells plus CP, histocompatibility antigens expressed on the surface of the spleen cells were essential to the antigen-stimulated cell destruction mechanism. Stem cells contained in the spleen cells also appeared to be crucial for maintaining tolerance by establishing a minimal degree of mixed chimerism.

Human fetal Schwann cells in culture: phenotypic expressions and proliferative capability

In this report we examined the phenotypic expressions and the proliferative capability of cultured human fetal Schwann cells. Antigens that were expressed included laminin, nerve growth factor receptor, neural cell adhesion molecule, S-100 protein, and that recognized by the monoclonal antibody HNK-1. In addition, HLA-A,B,C and HLA-DR, respectively, class I and class II antigens of the major histocompatibility complex, were demonstrated on Schwann cells. Mitotic capability was high, with an average of 34% of Schwann cells undergoing proliferation over a 2-day period.