Correlation between profile of circulating mononuclear cells and clinical manifestations in patients with pemphigus vulgaris

Phenotypes of 38 samples of mononuclear (PBMC) cells from 11 different patients with pemphigus vulgaris (PV) at different stages of the disease were explored looking for a possible relationship between cell immunity, mucocutaneous or mucosal lesion intensity and capacity of serum autoantibodies to elicit the disease in mice. PBMC from 5 patients with mucocutaneous lesions and sera with IgG capable of inducing the disease in neonatal mice had a high proportion of mature monocytes with CD14low DRhigh, and co-expressing CD16 and CD11b. In addition, a high proportion of CD19+CD5+ activated B cells and a very low proportion of naive CD4+CD45RA+ and CD8+CD11b+ T lymphocytes was observed. Monocytes from these patients expressed inducible nitric oxide synthase (iNOS). In contrast, PBMC from 6 patients, with lesions restricted to mucosal membranes and IgG lacking the capacity to induce the disease in mice, contained a high proportion of CD14high DRlow co-expressing CD16 circulating macrophages, CD8+CD11b+ T cells, and a low proportion of activated B lymphocytes. The results suggest a possible association between proportion of different antigen presenting cells (monocytes with high HLA-DR and low CD14 expression and activated B lymphocytes, or differentiated monocytes/macrophages), type of PV and capacity of serum autoantibodies to elicit the disease in mice.     

Marked increase of CD5 + B cells in hyperthyroid Graves' disease

We examined the proportions of B lymphocytes bearing CD5 cell surface antigen (CD5+ B cells), which are capable of making autoantibodies, in peripheral blood from patients with various thyroid diseases. The level of CD5+ B cells was markedly increased (>9.0%) above the normal range (0.5-7.7%) in untreated, hyperthyroid patients with Graves' disease, although about 10% of the patients had no detectable serum thyroid-stimulating hormone (TSH) receptor antibody (TRAb). However, the levels of CD5+ B cells were normal in untreated patients with destructive thyrotoxicosis due to aggravation of Hashimoto's thyroiditis or subacute thyroiditis. In patients with stimulated hyperthyroid Graves' disease the levels of CD5+ B cells were correlated with those of thyroid hormones and TRAb, all significantly increased. However, once hyperthyroidism was controlled by anti-thyroid drugs, CD5+ B cells were decreased, followed in turn by reduction of TRAb. We conclude that the proportion of CD5+ B cells is useful as a therapeutic index and for diagnosis of Graves' disease and its differentiation from destruction-induced thyrotoxicosis.     

"Diabetic rosettes": a cellular immunity marker in subjects at risk for type I diabetes

The authors have previously described a marker of cell-mediated, called "diabetic rosettes", revealed by the increased binding of CD3 CD4 lymphocytes from type I diabetic patients to beta-cell membrane antigens, as compared to lymphocytes from control subjects. In the present study, they have detected such "diabetic rosettes" in some subjects at risk for type I diabetes. The mean value of lymphocytes adhering to beta (RINm5F)-cells (beta-CL) was statistically higher in those subjects at risk than in control blood bank donors (p = 0.003). When a positive test was arbitrarily defined as a value of beta-CL higher than the 95th percentile of controls, 20 p. cent of the subjects at risk were classified as beta-CL+. No difference was observed between two subgroups of subjects at risk: first degree relatives of type I diabetic patients, and non-diabetic subjects with transient hyperglycaemia. "Diabetic rosettes" were associated with HLA DR 3/4 heterozygosity (p less than 0.04) and with a "low" acute insulin release to IV glucose (p = 0.05). They were not associated with islet-cell antibodies, insulin autoantibodies, or "activated" (HLA DR+) T-lymphocytes. The authors suggest that "diabetic rosettes" represent a marker of cellular immunity in some subjects at risk for type I diabetes.     

CD5+ B cells and naturally occurring autoantibodies in cancer patients.

We have determined the percentage of CD5+ B lymphocytes in the peripheral blood of cancer patients and healthy controls, using antibodies directed at the CD5 and CD19 (pan-B) markers. The frequencies of CD5+ B cells, expressed as a percentage of total B cells, ranged from 14.3 to 57.5% in the controls and from 14.8 to 82.8% in the patient population. One-third of the cancer patients had frequencies greater than 2 s.d. above the mean of the control population. The CD5+ B cell fraction expressed as a percentage of total lymphocytes was also significantly elevated in this group of cancer patients. These results suggest that the CD5+ B cell compartment may be affected by the malignant process or by the therapy modality employed. The plasma levels of several naturally occurring autoantibodies, the products of the CD5+ B cells, were also assessed in cancer patients and controls. No significant differences were observed when reactivity to several autoantigens was measured. These included nuclear components and phospholipids.     

Monoreactive and Polyreactive Rheumatoid Factors Produced by in Vitro Epstein-Barr Virus-Transformed Peripheral Blood and Synovial B Lymphocytes from Rheumatoid Arthritis Patients

The CD5 membrane molecule, initially identified as an exclusive T-cell marker, also defines a phenotypically and functionally distinct B-lymphocyte population. In normal individuals, CD5+ B cells are committed to secrete 'natural' polyreactive (auto)antibodies, that is antibodies, mainly IgM, endowed with multiple antigen-binding capabilities, including rheumatoid factor (RF) activity. At variance with this, in rheumatoid arthritis (RA) as well as in other autoimmune conditions, monoreactive autoantibodies binding with high affinity and specificity to a given self antigen have been isolated and the cells from which they originate differently related to the CD5+ B-lymphocyte subset. Here, we studied the proportions of CD5+ B cells and the characteristics, in terms of polyreactivity and monoreactivity, of RF produced by B lymphocytes in RA patients with classified disease activity. Our results suggest that patients with a more severe disease activity have higher proportions of CD5+ B cells and higher frequencies of B lymphocytes committed to secrete RF, with the characteristics of polyreactive antibodies. On the other hand, we did not find a significant difference between the proportions of peripheral B cells producing monoreactive RF in patients with high- versus patients with low-activity RA. However, in two highly active RA patients, we found that synovial fluid, compared with peripheral blood, was significantly enriched for (IgG and IgA) monoreactive RF-producing B cells.     

Altered processing of human insulin by B lymphocytes from an immunologically insulin-resistant type I diabetic patient.

Immunologically insulin resistant (IIR) type I diabetic patients possess significantly elevated levels of anti-insulin serum autoantibodies. We investigated whether altered insulin processing by B lymphocytes contributes to this form of insulin resistance. A comparison was made of the 125I-labelled human insulin (HI) peptides processed by Epstein-Barr virus (EBV)-transformed B lymphocytes derived from HLA-identical and nonidentical IIR with non-IIR type I diabetic patients on insulin therapy and healthy non-diabetic individuals. Several peptides detected in the extracellular, membrane-associated and intracellular compartments of B cells from an IIR type I diabetic patient differed from those found in the corresponding compartments of B cells from two non-IIR type I diabetic patients and two normal individuals. These data suggest that HI is processed differently by B cells from an IIR type I diabetic patient compared with B cells from non-IIR type I diabetic patients and normal individuals. Further, we found that two of the five plasma-membrane associated processed HI peptides on the IIR patients' B cells were absent from the membrane compartments of the other B cell lines examined. Thus, it is possible that one or both of these peptides, unique to the IIR patient's B cells, consist of an immundominant epitope(s) that stimulates the production of insulin autoantibodies which mediate the onset of IIR in type I diabetes.     

Association of viral load in plasma samples of HIV-infected hemophilia patients with autoantibodies and gp120-containing immune complexes on CD4 lymphocytes

Objective: We investigated whether the induction of antilymphocyte autoantibodies and immune complexes is associated with the activity of HIV replication. Methods: Viral HIV-1 RNA was measured in the plasma samples of 84 HIV+ hemophilia patients and correlated with the IgM, IgG, IgM/IgG and IgM/IgG/gp120 load of circulating CD4⁺ lymphocytes, CD4⁺ and CD8⁺ cell counts, plasma neopterin levels and in vitro T-cell responses to mitogens and pooled allogeneic stimulator cells. Results: Compared to patients with no immune complexes, on circulating CD4⁺ lymphocytes, viral load was increased in patients with IgM, IgM/IgG or IgM/IgG/gp120 complexes. Sequential analysis of HIV+ patients showed that peaks of retroviral activity were associated with the subsequent formation of CD4⁺ lymphocyte-reactive IgM and IgG autoantibodies and gp120-containing immune complexes. Conclusion: The induction of autoantibodies and immune complexes attached to CD4⁺ lymphocytes is associated with periods of increased viral activity in HIV-infected patients.     

CD5 expression on B cells may be an activation marker for secretion of anti-myelin antibodies in patients with polyneuropathy associated with monoclonal gammopathy.

B cells expressing the CD5 marker belong to a subpopulation with potential autoreactive properties. Increased proportions of CD5+ B cells have been reported in autoimmune diseases. In patients with monoclonal gammopathy and demyelinating polyneuropathy, the M-component often consists of autoantibodies reacting with myelin components. We therefore investigated if CD5+ B cells were involved in the production of anti-myelin antibodies. There was no difference of mean value of CD5+ B cells between patients and controls. However, the proportion of CD5+ B cells was significantly correlated with the amount of anti-myelin antibodies. In seven patients, CD5+ B cells were enriched using an immunomagnetic technique. The number of CD5+ and CD5- B cells secreting anti-myelin antibodies was determined by ELISPOT. In two patients with high levels of antibodies, antibody-secreting cells were mainly, but not exclusively, CD5+ B cells. In five patients with low levels of antibodies, most cells secreting anti-myelin antibodies were CD5-. We conclude that CD5 expressed on B cells may be an activation marker, reflecting B cells producing high amounts of anti-myelin antibodies in patients with polyneuropathy associated with monoclonal gammopathy.     

Enhanced percentage of CD5+ B lymphocytes in newly diagnosed IDDM patients.

The percentage of CD5+ B lymphocytes, the prevalence of islet cell antibodies (ICA) and of anti-insulin autoantibodies (IAA) and HLA-A-B-C and DR antigens were studied in 32 newly diagnosed insulin-dependent diabetes mellitus (IDDM) patients, in 12 non-insulin-dependent diabetes mellitus (NIDDM) patients and in 12 healthy subjects. The percentage of CD5+ B lymphocytes ranged from 18% to 51.2% (mean 40.3 +/- 11%) in IDDM patients, whereas in NIDDM patients and in controls it ranged from 20% to 25.2%, (mean 21.3 +/- 4.1%) and from 16% to 24%, (mean 19.3 +/- 1.9%), respectively (P less than 0.01 vs. NIDDM patients and vs. controls). There was no correlation between a higher percentage of CD5+ B lymphocytes and the presence of ICA and/or IAA, and their titres, and/or of any HLA-A-B-C and DR antigens. Thus, an enhanced percentage of CD5+ B lymphocytes may be present in newly diagnosed IDDM patients; the possible role of this cell type in the pathogenesis of IDDM needs further investigation.     

Immunological functions of oxidized human immunoglobulin G in type 1diabetes mellitus: its potential role in diabetic smokers as a biomarker of elevated oxidative stress

The role of oxidized immunoglobulin G in type 1 diabetic smokers has been investigated in the present study. Human immunoglobulin G (IgG) was modified by reactive oxygen species (ROS). The binding characteristics of circulating autoantibodies in type 1 diabetes patients against native and modified IgG were assessed by direct binding ELISA. High degree of specific binding by 68.5% of patients sera towards ROS-modified IgG was observed in comparison to its native analogue (p< 0.05). In addition, diabetic smokers (n=28) were examined and the results were compared with diabetic non-smokers (n=26). Circulating antibodies of diabetic smokers showed substantially stronger binding to modified IgG as compared with the antibodies present in diabetic non-smokers (p< 0.05). Normal human sera (n=53) showed negligible binding with either antigen. Competitive inhibition ELISA reiterates the direct binding results. The increase in total serum protein carbonyl levels in the diabetic smokers was largely due to an increase in oxidized IgG. Diabetic smokers showed substantially higher carbonyl contents in sera as well as in purified IgG as compared with sera and IgG of diabetic non-smokers. Collectively, the oxidation of plasma proteins, especially IgG, might enhance oxidative stress in type 1 diabetes smokers.     

Relationship between CD5+ B lymphocytes and the activity of systemic autoimmunity.

We studied the relationship between CD5+ B cells and the activity of the disease process in patients with autoimmune diseases. In rheumatoid arthritis (RA), levels of CD5+ B cells were associated with autoantibody production as determined by serum rheumatoid factor and antinuclear antibodies. In addition, CD5+ B cells were significantly correlated with C-reactive protein, and data from longitudinal studies showed a marked influence of corticosteroid treatment on numbers of CD5+ B cells. Patients with systemic lupus erythematosus (SLE) had slightly elevated levels of CD5+ B cells as compared with normals, but a close association with measures of an active disease was not observed. In a group of patients with type I diabetes mellitus, CD5+ B cells were detected in patients with anti-islet cell antibodies. Our results suggest that CD5+ B cells are related to the activity of the autoimmune process and can be modulated by therapy in patients with RA. Although CD5+ B cells do not seem to have a major role in SLE, polyclonal activation might affect this B cell subset as well in this disease. Further studies are needed to define the precise role of CD5+ B cells in organ-specific autoimmunity.     

Correlation between Profile of Circulating Mononuclear Cells and Clinical Manifestations in Patients with Pemphigus Vulgaris

Phenotypes of 38 samples of mononuclear (PBMC) cells from 11 different patients with pemphigus vulgaris (PV) at different stages of the disease were explored looking for a possible relationship between cell immunity, mucocutaneous or mucosal lesion intensity and capacity of serum autoantibodies to elicit the disease in mice. PBMC from 5 patients with mucocutaneous lesions and sera with IgG capable of inducing the disease in neonatal mice had a high proportion of mature monocytes with CD14^lowDR ^gh and co-expresing CD16 and CDllb. In addition, a high proportion of CD19⁺CD5⁺ activated B cells and a very low proportion of naive CD4⁺CD45RA⁺ and CD8⁺CDllb⁺ T lymphocytes was observed. Monocytes from these patients expressed inducible nitric oxide synthase (iNOS). In contrast, PBMC from 6 patients, with lesions restricted to mucosal membranes and IgG lacking the capacity to induce the disease in mice, contained a high proportion of CD14^hlg DR^low co-expressing CD16 circulating macrophages, CD8⁺CDllb⁺ T cells, and a low proportion of activated B lymphocytes. The results suggest a possible association between proportion of different antigen presenting cells (monocytes with high HLA-DR and low CD 14 expression and activated B lymphocytes, or differentiated monocytes/macrophages), type of PV and capacity of serum autoantibodies to elicit the disease in mice     

Fetal type lymphocytes in insulin dependent diabetes mellitus.

CD5+ B and gamma/delta T lymphocytes constituting a major population in the fetus and newborn infant, represent two small subsets of the B and T lymphocyte compartment in healthy adults. There is evidence for their potential involvement and relative expansion in autoimmune disorders. In insulin-dependent diabetes mellitus (IDDM) CD5+ B lymphocyte counts have been found to be increased or normal. The aim of our study was to determine the percentage of both "fetal type" lymphocyte subsets in peripheral blood of 22 recently diagnosed children with IDDM, in that of 13 high risk subjects (islet cell antibody (ICA) positive non-diabetic Ist degree relatives of diabetic children) and in 43 healthy controls. The percentage of gamma/delta TCR+ cells and of CD5+ B lymphocytes was found to be significantly (p < 0.0001 and p = 0.03, respectively) higher in the diabetic and prediabetic groups as compared to controls. Young children with IDDM associated antibodies carry a higher risk of developing clinical IDDM than older individuals. In our hands, the percentage of both CD5+ B and gamma/delta T lymphocytes was higher in the younger population. However, age-dependent decrease for both lymphocyte subpopulations in IDDM-prediabetic patients was less than in healthy controls. Since the above subpopulations are supposed to play a role in immune response to conserved structures, these observations would suggest a higher capacity of older individuals to 'natural autoimmunity" and would explain at least in part the increased risk of antibody positive young children to develop IDDM.     

B lymphocyte subsets in Hashimoto's thyroiditis

Two B lymphocyte subsets are identified on the basis of possession or lack of a surface molecule, CD5. The CD5+ B lymphocytes synthesize autoantibodies and in the process rearrange proximal variables of immunoglobulin genes. We have here studied the proportion and absolute counts of CD5+ B lymphocytes in the peripheral blood of 31 patients with Hashimoto's thyroiditis and related the findings to their HLA phenotypes and clinical features. Although the percentage and absolute number of surface immunoglobulin-positive (B) lymphocytes was comparable in patients to those in twenty controls, % CD5+ was significantly higher in the patient group (38.1 +/- 11.6 [+/- S.D.] vs. 27.9 +/- 10.1, p = 0.009). The absolute CD5+ cells (microliters) were also higher in patients with Hashimoto's thyroiditis (77.90 +/- 37.50 vs. 55.1 +/- 29.8, p = 0.020). The proportion of CD5+ cells was even higher in HLA-DR3 positive patients (43.1% +/- 7.2, n = 13) compared to six DR3+ controls (26.17% +/- 9.7, p = 0.0005). The difference between DR3- patients and controls was not significant (28.6% +/- 10.5 vs. 34.4% +/- 13.0). As the CD5 molecule may be induced on activated B lymphocytes, this study suggests that Hashimoto's thyroiditis is associated with an increase of activated B lymphocytes engaged in autoantibody synthesis. This defect is particularly obvious in DR3+ patients.     

Circulating phenotypic B‐1 cells are decreased in common variable immunodeficiency and correlate with immunoglobulin M levels

B‐1 cells are innate‐like lymphocytes characterized by spontaneous production of ‘natural’ polyspecific antibodies, often of self‐specificity, and thought to be responsible for tissue homeostasis, mucosal protection, maintaining resting serum immunoglobulin (Ig)M levels and for early immunoglobulin production following infection. Although defined most clearly in mice, a human B‐1 cell counterpart, defined by the phenotype CD19 or 20⁺CD27⁺CD43⁺CD69 or 70^–, has been proposed recently, facilitating a study of their role in human humoral immunodeficiencies, such as common variable immunodeficiency (CVID). This study examined circulating B‐1 cells in 27 CVID patients in comparison to age‐matched controls (n = 28). Phenotypic putative B‐1 cell proportions varied widely, but there was an overall 60–70% decrease in CVID (0·039 ± 0·033% of lymphocytes, mean ± standard deviation) compared with controls (0·110 ± 0·159% of lymphocytes, P = 0·0012). This decrease was, however, explained largely by concomitant loss of total CD27⁺ memory B cells characteristic of CVID, although those with higher memory B cell proportions appeared to show a true decrease. No age‐related effects were apparent in B‐1 cell proportions. However, among CVID patients, there was a strong positive correlation between the B‐1 cell proportion and serum IgM levels, a relationship that was not evident for IgA, nor was there a relationship between memory B cell proportions and serum IgM. Patients with CVID have fewer circulating putative phenotypic B‐1 cells, which largely reflected the overall decrease in memory B cells. However, B‐1 cell proportions correlated with resting serum IgM levels, suggesting a possible role in IgM deficiency in CVID.     

Immunoglobulin heavy chain variable region gene utilization by B cell hybridomas derived from rheumatoid synovial tissue.

Rheumatoid arthritis (RA) is a chronic inflammatory disease that primarily affects synovial joints. Activated B lymphocytes and plasma cells are present in the synovial tissue and are thought to contribute to the immunopathology of the rheumatoid joint. To investigate rheumatoid synovial B lymphocytes, we have generated B cell hybridomas from synovial tissue of an RA patient. Here we describe the immunoglobulin VH gene repertoire of eight IgM- and 10 IgG-secreting synovial-derived hybridomas. The VH4 gene family is highly represented (38.5%) in this panel of hybridomas compared with the frequency of VH4 gene expression in circulating B lymphocytes reported previously (19-22%) and with the VH4 gene frequency we observed in a panel of hybridomas derived in the same manner from the spleen and tonsil of normal individuals (19%). The increased frequency of VH4 gene expression was not due to the expansion of a single B cell clone in vivo as none of these hybridomas was clonally related. Two synovial-derived hybridomas secreted autoantibodies; one (VH3+) secreted an IgM-rheumatoid factor (RF) and the other (VH4+) secreted IgM with polyreactive binding to cytoskeletal proteins and cardiolipin. The antibodies secreted by the remaining synovial-derived hybridomas were not reactive with the autoantigens tested. The VH gene usage in a proportion (5/17) of synovial-derived hybridomas that expressed CD5 antigen provided preliminary evidence that CD5+ B cells in RA synovium have a similar increase of VH4 gene expression reported for CD5+ B cells from normal individuals and patients with chronic lymphocytic leukaemia.     

Spontaneous IgM Autoantibody Production In Vitro by B Lymphocytes of Normal Human Neonates

Human neonate B lymphocytes display unique phenotypic and functional characteristics: in addition to CD1c antigens, CD5+ and CD5- subsets both express activation markers such as CD23 and Bac-1. They proliferate strongly in the presence of various lymphokines (rIL-2, rIL-4, low molecular weight BCGF), but differentiate poorly in the presence of the same lymphokines, pokeweed mitogen and Epstein-Barr virus. It has also been reported that human neonate B lymphocytes produce polyreactive autoantibodies after in vitro activation by Staphylococcus aureus Cowan I and transformation by Epstein-Barr virus. We now show that, in the absence of in vitro stimulation, human neonate B lymphocytes produce polyreactive antibodies of the IgM isotype against several autoantigens. The B lymphocytes involved expressed membrane IgD, IgM, CD23 and CD11b molecules; CD5 expression was variable. This phenotype was consistently found on a minority of B lymphocytes and is similar to that of polyreactive autoantibody-producing B cells in mice. We also found that autoantibody production in vitro could occur in the absence of any T helper effect. The function of these autoantibodies is not clearly established, but their occurrence in a large proportion of human neonates strongly suggests that they play an important role in the development of the immune system.     

Age-related changes in surface antigens on peripheral lymphocytes of healthy children.

The age-related changes in proportion of various subsets within lymphocytes were investigated in cord blood and peripheral blood from healthy children and adults. The percentages of T and B cells did not show age-related changes, whereas natural killer (NK) cells increased significantly with age. Within lymphocytes or the CD3+ T cell population the proportion of CD45RAbright+ lymphocytes decreased and that of CD45RO+ cells increased, while that of CD45RAdim+ cells showed no age-related change. Within lymphocytes, the percentage of CD45RAbright+ CD4+ cells decreased, together with a decline of that of CD4+ cells. The proportions of CD45RAbright+ CD8+ cells and S6F1bright+ CD8+ cells increased with age, and the age-dependent increase of the proportion of CD8+ cells seems to be mainly attributable to the increases in these subsets. The CD45RAdim+ CD4+ and CD45RAdim+ CD8+ cells co-expressing CD45RO at a low level nevertheless showed no age-related changes. In gamma delta T cells, both delta TCS1+ and delta TCS1- T cells increased with age, but the delta TCS1- gamma delta T cells increased more than the delta TCS1+ subset. Among lymphocytes, the percentages of CD20+, CD21+ and CD22+ cells remained similar, with no age-related changes, but the proportion of CD5+ cells within lymphocytes or B cells decreased. The proportions of CD16+ NK cells among lymphocytes increased with age, and this change was attributable to the increase of CD56+ cells.     

CD23 antigen expression on B lymphocytes and soluble CD23 levels in peripheral blood of high-risk type 1 diabetes subjects

Soluble CD23 (sCD23), a recently discovered multifunctional cytokine, is a 25-kDa molecule released by autoproteolysis from the 45-kDa CD23 molecule which is found mainly on the surface of B lymphocytes. In the present study we aimed to evaluate, in association with humoral immune and metabolic markers, the changes in CD23 antigen expression on B lymphocytes and levels of sCD23 in the peripheral blood of subjects at high risk of type 1 diabetes. The study was carried out in 28 first-degree relatives of type 1 diabetes patients (versus a control group of 28 age- and sex-matched healthy volunteers) using antibodies against different B-cell antigens: ICA, GADA, IAA, IA-2. Flow cytometry was used to measure the percentage of CD20+ (B lymphocytes) and CD20+CD23+ lymphocyte subsets, and sCD23 levels in serum were determined by enzyme immunoassay. Prediabetic subjects had a significantly (P<0.01) lower percentage of CD20+CD23+ lymphocytes in comparison with healthy age- and sex-matched controls. Expression of CD23+ on B lymphocytes was similar in subjects with ICA only and with two or more antibodies against pancreatic antigens. In the prediabetic group, the median concentration of sCD23 was lower than in the control group and was statistically significant (P < 0.02) in the subgroup of subjects with the most impaired function of pancreatic beta-cells (the lowest values of first phase of insulin release). In conclusion, our study suggests that CD23 molecule expression on B lymphocytes and sCD23 levels in peripheral blood could be additional markers for monitoring the development of type 1 diabetes and play a role in determining the efficacy of prevention trials. However, further prospective studies are needed.     

Simultaneous activation of natural killer T cells and autoantibody production in mice injected with denatured syngeneic liver tissue

Denatured syngeneic liver tissue prepared by mechanical procedures was intraperitoneally injected into adult C57BL/6 mice. In parallel with a decrease in the total number of lymphocytes in the liver, spleen, and thymus from days 1-7 after the injection, the proportion of the CD4+NK1.1+CD3(int) subset of these cells (i.e. natural killer T or NKT cells) increased in the liver. Even the absolute number of these NKT cells increased in the liver on days 14 and 21. In response to the injection of denatured liver tissue, tissue damage was induced in the liver, as shown by elevated levels of serum transaminases and hepatocyte degeneration observed by electron microscopy. Sera obtained on days 7 and 14 contained autoantibodies including anti-DNA antibodies. The proportion of CD1d(high)B cells in the liver was found to decrease on days 1-7. In other words, denatured liver tissue stimulated both NKT cells and certain B cells in the liver. These results suggest that liver lymphocytes might contain not only autoreactive T cells (e.g. CD3(int) or NKT cells) but also some B cells (e.g. B-1 cells) which produce autoantibodies and that the denatured tissue had the potential to stimulate these lymphocytes and to evoke an autoimmune-like state.