Beta 2m Research Articles

Expression of Specific Granule Markers on the Cell Surface of Neutrophil Cytoplasts

The widespread assumption that cytoplasts generated from human polymorphonuclear leukocytes (PMNs) are vesicles consisting solely of cytoplasm surrounded by plasma membrane and devoid of granule activity remains to be tested. PMN cytoplasts were prepared by centrifugation of intact cells on a Ficoll step gradient in the presence of cytochalasin B. Two granule membrane markers, Mol, a fluorometrically detectable antigen, and cytochrome b, both of which have been shown to translocate to the plasma membrane during granule release, were compared for their activity in cytoplasts and intact PMNs. We found that the amount of Mol detected on the plasma membrane of intact PMNs, as compared with other membrane markers (such as antigens LFA-1 and beta 2m), increased 1.6-fold upon exposure of PMNs to Ficoll plus cytochalasin B prior to centrifugation. Another twofold increase in Mol expression occurred upon cytoplast preparation. Release of the granule enzymes, vitamin B12-binding protein, and lysozyme were also followed and correlated well (r = .78 and .92) with the amount of Mol antigen present on the cell surface. Cytochrome b was also found to be higher (1.4-fold) on plasma membranes isolated from cytoplasts than on plasma membranes isolated from intact control cells. These results indicate that some fusion of granule membranes and plasma membranes occurred during treatment of PMNs with Ficoll plus cytochalasin b and during cytoplast preparation.

Representations of $$\zeta (2n + 1)$$ and Related Numbers in the Form of Definite Integrals and Rapidly Convergent Series

Let $$\zeta (s)$$ and $$\beta (s)$$ be the Riemann zeta function and the Dirichlet beta function. The formulas for calculating the values of $$\zeta (2m)$$ and $$\beta (2m - 1)$$ ( $$m = 1,\;2,\; \ldots $$ ) are classical and well known. Our aim is to represent $$\zeta (2m + 1)$$ , $$\beta (2m)$$ , and related numbers in the form of definite integrals of elementary functions and rapidly converging numerical series containing $$\zeta (2m)$$ . By applying the method of this work, on the one hand, both classical formulas and ones relatively recently obtained by others researchers are proved in a uniform manner, and on the other hand, numerous new results are derived.

Pathogenic CD8+ Epidermis-Resident Memory T Cells Displace Dendritic Epidermal T Cells in Allergic Dermatitis

The skin is our interface with the outside world, and consequently it is exposed to a wide range of microbes and allergens. Recent studies have indicated that allergen-specific skin-resident memory T (TRM) cells play a role in allergic contact dermatitis (ACD). However, the composition and dynamics of the epidermal T-cell subsets during ACD are not known. Here we show that exposure of the skin to the experimental contact allergen DNFB results in a displacement of the normally occurring dendritic epidermal T cells (DETC) concomitant with an accumulation of epidermal CD8+CD69+CD103+ TRM cells in mice. By studying knockout mice, we provide evidence that CD8+ T cells are required for the displacement of the DETC and that DETC are not required for recruitment of CD8+ TRM cells to the epidermis following allergen exposure. We demonstrate that the magnitude of the allergic reaction correlates with the number of CD8+ epidermal TRM cells, which again correlates with allergen dose and number of allergen exposures. Finally, in an attempt to elucidate why CD8+ epidermal TRM cells persist in the epidermis, we show that CD8+ epidermal TRM cells have a higher proliferative capability and are bioenergetically more stable, displaying a higher spare respiratory capacity than DETC.

Long-Term Exposure to Pomalidomide-Dexamethasone in Pts with Refractory Myeloma

Background. The IFM2009-02 study was launched in 2009, and randomized 84 patients (pts) with pomalidomide (oral 4 mg daily) and dexamethasone (oral 40 mg weekly) given either 21 days out of 28 or continuous. Whilst the overall median PFS was 4.6 months - this end stage very advanced RRMM population, we observed that 40% of the patients had a prolonged PFS and subsequently OS in the trial.We sought to analyze the characteristics of 58 pts that had more than 3 months of pomalidomide to study the effect of long exposure to Pomalidomide.Method. IFM 2009-02 was a multicentre phase 2 study of pts with RRMM who had at best a stable disease with the last course of bortezomib and of lenalidomide, or who were refractory to bortezomib and lenalidomide (IMWG). This analysis was performed on the ITT population combining data from the 2 study arms. We have analyzed the characteristics of pts according to duration of treatment with pomalidomide and dexamethasone 3 months to one year (<1 year) or more than one year (≥1 year).Results. 60% and 40% of pts were exposed to pomalidomide for <1 year and ≥1 year, respectively. The ORR for the <1 year group was 43%, the median PFS 4.6 months (CI95% 4;6) with only 6% at 12 months, and the median OS 15 months (4;6) and 65% at 12 months, 40% at 18 months. For the ≥1 year group, the response rate and survival were strikingly different, ORR at 83%, PFS 20.7 months, OS not reached (CI95% 40;-) and 100% at 12 months, 91% at 18 months. Of the pts in the <1 year, 87% have died versus 35% in the ≥1 year group. Of note, death of most pts occurred during the follow up period post pomalidomide therapy , however in a far greater extent for the <1 year group, 96% versus 67%, that could suggest it was more difficult to salvage these pts post pomalidomide.We next sought to identify the characteristics of the 2 groups. Interestingly, the median number of prior lines was similar across groups, 5 (range 1-10), with 89% and 79% of the pts exposed to more than 3 lines and 17% and 22% exposed to more than 6 lines, for the <1 year and ≥1 year groups, respectively. 40% and 48% of pts had Bortezomib as last line, 29% and 43% Lenalidomide, 43% and 26% and alkylating agent. Similarly, 80% and 74% of pts were refractory to Bortezomib, 89% versus 87% to Lenalidomide, 65% versus 75% to alkylating agents, 74% and 87% to the last line of therapy, respectively. 74% and 70% were double refractory (Bortezomib and Lenalidomide) and 60% and 70% were triple refractory (double +last line), respectively. The time from diagnosis to IFM 2009-02 study entry was also similar between cohorts, 5.8 and 6.5 years for <1 year and ≥1 year groups; however with 6% versus 26% of pts, entering the study in less than 3 years since diagnosis. There was no difference in terms of patients characteristics between groups, either patients-based such as gender, age, weight, or myeloma-based characteristics.However, serum beta 2m level was higher at diagnosis in the <1 year compared to the ≥1 year, 54% versus 35%, with a slightly more adverse cytogenetic profile 35% versus 12%, with the limitation that this was not available for all the patients. Presence of plasmacytoma/EMD was also greater in the former group, 20% versus 4%, respectively. It seems that the <1 year had more intrinsic adverse features of the tumor cells compared to the ≥1 year group.There was no clear difference in terms of safety management of pomalidomide and/or dexamethasone, with respect to the daily dose intensity of Pomalidomide (median, 3.0 and 2.9 mg/day), and the relative dose intensity of pomalidomide that was 89% and 84%, respectively; similar to the rate of dose reduction and dose interruption.Conclusion. Pomalidomide and dexamethasone is effective and well tolerated in these heavily pre-treated MM pts refractory to Bortezomib and Lenalidomide, with approximately 40% of the patients having a prolonged exposure to treatment, which translated into a significantly prolonged OS. Our study suggests that patients with more intrinsic adverse features of Myeloma tumor cells could not have prolonged exposure to pomalidomide as they progressed within a year from start of pomalidomide. Future studies should examine optimizing pomalidomide therapy in those patients, such as using multidrug pomalidomide-based combined regimens to prolong exposure to pomalidomide and improve the survival of these patients. DisclosuresKarlin:Janssen: Honoraria; celgene: Consultancy, Honoraria; Sandoz: Consultancy. Stoppa:Celgene Jansen: Honoraria.

平常生活活動時の微量尿蛋白および酵素N-acetyl-β-D-glucosarninidase(NAG)尿中排泄の日内変動

The present investigation was performed to confirm the relationship between the circadian variation of microproteinuria and physical activity. Urine samples from 10 normal male volunteers, collected during six consecutive 4-h periods, were examined for albumin, alpha 1-, beta 2-microglobulin, NAG, electrolytes and hormones. The fluctuations in heart rate (HR) and blood pressure (BP) over 24-h were measured at 30-min and 1-h intervals, respectively. Energy expenditure (EE) was calculated using the equation of regression between HR and oxygen uptake measured on another day. The variations of HR (delta HR) and EE (delta EE) based on a 24-h average (bpm and kcal/kg/h) were used as indices of change in physical activity during an ordinary day. The correlation coefficients between delta HR and the variations of albumin (delta Alb) and beta 2-microglobulin (delta beta 2M) from the 24-h average (micrograms/h.cr 1 mg) were 0.619 and 0.670 (p less than 0.001), respectively. Increased excretions of both glomerular and tubular proteins were correlated with the increase in HR and/or EE during daytime activity. During rest time at night, the variations in alpha 1M, beta 2M and NAG excretion were different from the variations in albumin. A temporary inhibition of tubular protein excretion was observed only in the early morning (04:00-08:00), although albumin excretion was inhibited throughout the nighttime. These findings suggested that physical activity may influence the diurnal variations in protein excretions, that albuminuria may be more sensitive to daytime activity, and that fluctuation of tubular protein excretion may be preferably controlled by an endogenous mechanism. Timed overnight or first-morning urine may be recommendable as a sample for determination of microalbuminuria for screening of clinical diabetic nephropathy.

長期透析症例における破壊性脊椎関節症(DSA)の経年変化に関する検討(第1報)

This study was undertaken to evaluate destructive spondylarthropathy (DSA) in patients long-term dialysis. The patients were investigated by plain X-ray examinations twice with a three-year interval, and the changes in severity of the illness in 66 patients undergoing dialysis for over 5 years were defined. Group A (9 patients) consisted of patients with progression in grades during the three years, while group B (57 patients) consisted of patients without deterioration. There was no differences in the two groups in age, duration and the modality of dialysis. However, in group A, the level of plasma beta 2-microglobulin (beta 2M) was 33.5 +/- 14.6 micrograms/ml at the first observation, and 33.1 +/- 15.1 micrograms/ml at the second (NS). In group B, the level of plasma beta 2M was 45.6 +/- 8.13 micrograms/ml at the first observation, and 39.7 +/- 9.18 micrograms/ml at the second (p <0.05). No improvement in DSA was observed. The result of this study suggests that DSA will not improve once it has become overt, and the management for lowering the level of beta 2M may prevent the occurrence and progression of DSA.

Identification of HLA-A24-Binding Peptides of Mycobacterium tuberculosis Derived Proteins with Beta 2m Linked HLA-A24 Single Chain Expressing Cells

Tuberculosis is caused by an intracellular pathogen Mycobacterium tuberculosis (Mtb) and poses a persistent threat to global health. MHC class I-restricted CD8 cytotoxic T lymphocytes (CTL) are essential for protective immunity to Tuberculosis. Information for CTL epitopes derived from Mtb is desirable for vaccine design and assessment of T cell responses. However, the knowledge about CTL epitopes of Mtb, particularly those non-A2 HLA alleles restricted is rare. In this study, beta-2-microglobulin (beta 2m, β2m) linked HLA-A24 single chain was expressed on RMA-S cell line defective in the endogenous antigen processing and applied for screening of peptides which could stabilize the HLA-A24 complex on the cell surface. From a group of peptides predicted as binders by a computer algorithm, five peptides were shown to bind to HLA-A24 protein on the cell surface. As comparison we have also identified a dozen Mtb proteins derived peptides that bind to HLA-A2 specifically. The cell line and HLA binders present here would be useful for further identification of CD8 restricted Mtb epitopes.

CSF follow-up in HIV-1 infection: intrathecal production of HIV-specific and unspecific IGG, and beta-2-microglobulin increase with duration of HIV-1 infection.

Ninety-nine sequential cerebrospinal fluid (CSF) samples from 28 human immunodeficiency virus-1 (HIV-1)-infected patients were analyzed during the follow-up of 9 months to 4 years. Intrathecal synthesis of HIV-antibodies and IgG (p < 0.01), and the levels of beta-2-microglobulin (beta 2m) in the CSF (p < 0.05) and serum (p < 0.01) increased with duration of HIV-1 infection. No effect of duration of HIV-1 infection was observed on the individual CSF white cell counts and the levels of blood-brain-barrier (BBB) permeability. In 13 patients with HIV-1-associated central nervous system (CNS) disease, the effect of duration was seen as an increase of the individual beta 2m levels in serum (p < 0.01). Moreover, 7 of 9 patients who developed neurological disease or showed its progression during the study increased the level of beta 2m in the CSF. All of them increased the level of beta 2m in serum. In 15 neurologically healthy subjects, the effect of duration was expressed as an increase of the level of individual beta 2m in CSF (p < 0.05) and intrathecal IgG synthesis (p < 0.01). In the AIDS group, the level of beta 2m in the CSF increased, but in less severe stages the dependency of the individual CSF parameters on disease duration was not found. Our results indicate that elevated levels of beta 2m in CSF and serum appear to predict progression of neurological and systemic diseases, respectively. Elevated beta 2m in the CSF of clinically intact individuals may indicate subclinical neurological disease caused by HIV-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta-2-microglobulin is superior to N-acetyl-beta-glucosaminidase in predicting prognosis in idiopathic membranous nephropathy

An accurate prediction of prognosis in patients with idiopathic membranous nephropathy (iMN) would allow restriction of immunosuppressive treatment to patients who are at highest risk for end-stage renal disease (ESRD). Several markers of proximal tubular cell injury have been used as predictors of prognosis. In this study we compared the accuracy of urinary beta-2-microglobulin (U beta 2m) and N-acetyl-beta-glucosaminidase (U beta-NAG) in predicting renal insufficiency and remission rates. Fifty-seven patients with iMN (38 M, 19 F; age 48 +/- 16 years), a nephrotic syndrome and a serum creatinine level <135 micromol/l were studied prospectively. At baseline, a standardised measurement was carried out to determine renal function and protein excretion. The end-point renal failure was defined as a serum creatinine exceeding 135 micromol/l or an increase in serum creatinine by >50%. Remission was defined as a proteinuria <2.0 g/day with stable renal function. The mean follow-up was 80 +/- 36 months. The mean serum creatinine concentration was 89 +/- 20 micromol/l, serum albumin 24 +/- 5.3 g/l and proteinuria 8.9 +/- 4.8 g/24 h. Thus far, 28 (49%) patients have reached the predefined end point of renal failure. Multivariate analysis identified U beta 2m as the strongest independent predictor for the development of renal insufficiency. Sensitivity and specificity were 81 and 90% respectively for U beta 2m (threshold value 54 microg/mmol cr), and 74 and 81% respectively for U beta-NAG (threshold value 2.64 U/mmol cr). The overall remission rate was 44%. A remission occurred in 78% of patients with low U beta 2m and in 14% of patients with high U beta 2m, and respectively in 71% of patients with low U beta-NAG and 21% of patients with high U beta-NAG. Although both U beta 2m and U beta-NAG predicted progression and remission in iMN, U beta 2m was more accurate. High specificity in predicting prognosis should be pursued to avoid unnecessary immunosuppressive therapy. We therefore conclude that U beta 2m is superior to U beta-NAG in predicting prognosis in patients with iMN.

Factors Released from Cholestatic Rat Livers Possibly Involved in Inducing Bone Marrow Hepatic Stem Cell Priming

Previous studies have shown that bone marrow beta 2m(-)/Thy-1+ hepatic stem cells (BMHSCs) were able to engraft in vivo and differentiate into functioning hepatocytes in vitro. Our transcriptomic profiling on BMHSCs derived from rats subjected to common bile duct ligation (CBDL) demonstrated CBDL-derived beta 2m(-)/Thy-1+ BMHSCs expressed hepatocyte-like genes and shared more commonly expressed genes with hepatocytes, suggesting that an "on-site" priming of BMHSCs into hepatocyte lineage was initiated under the condition of CBDL. In this paper, transcriptomic profiling was carried out on livers from rats with CBDL to identify candidate factors released from cholestatic livers possibly involved in the priming of BMHSCs using Affymetrix Rat Genome U34A arrays. In CBDL rat livers, 1,091 probe sets were differentially expressed, of which 188 up-regulated probe sets were annotated as "extracellular" components. Gene ontology analysis showed many up-regulated genes belonged to cytokines, chemokines and growth factors, including Il1b, Il18, Ptn, Spp1, Grn, Ccl2, Cxcl1, Pf4, Tgfb, and Tgfb3. Cell differentiation and proliferation regulation factors such as Dmbt1, Efna1, Lgals1, Lep, Pmp2, and Gas6 were also induced in CBDL livers. Furthermore, many proteolysis and peptidolysis genes such as Mmp2, Mmp12, Mmp14, and Mmp23 were up-regulated in CBDL livers. Gene expression profiling showed that many cytokine-, chemokine-, growth factor- as well as certain extracellular protein-related genes were induced in CBDL livers, suggesting that these genes may be involved in hepatic BMHSCs priming.

Evaluation of Two Beta2-microglobulin Reagents by Turbidimetric Immunoassay

An increased level of beta 2-microglobulin (beta 2M) is seen in diseases such as lymphoproliferative diseases, renal diseases, solid tumors, liver diseases, certain viral infection, or chronic inflammatory diseases, etc. In this study, we evaluated a quantitative beta 2M assay for precision and linearity using an automated turbidimetric immunoassay (TIA) by Hitachi 7600-110 (Hitachi High Technologies Co., Japan). The TIA of beta 2M was compared with a chemiluminescent immunoassay (CLIA) by Immulite 2000 (Diagnostic Products Corporation, USA). Two TIAs, the Hitachi 7600-110 with Roche reagent (Roche-TIA) and the Hitachi 7600- 110 with HBI reagent (HBI-TIA), were evaluated for within-run precision, within-day precision, betweendays precision, and linearity. With 68 serum samples, two TIAs were compared with Immulite 2000 using DPC reagent (DPC-CLIA). These data were analyzed by Passing-Bablok analysis and Bland- Altman analysis. The coefficients of variation (CVs) of within-run precision, within-day precision, and between- days precision were less than 7% in all groups. The linearity tests of the two TIAs were maintained well (Roche-TIA: R2=0.9952; HBI-TIA: R2=0.9946). The comparison study indicated good correlations (Roche-TIA/DPC-CLIA: r=0.9738, y=0.9625x-0.0375; HBI-TIA/DPC-CLIA: r=0.9725, y= 1.1000x-0.3100). In Bland-Altman analysis, less than 2SD differences were observed between the two groups. Both Roche-TIA and HBI-TIA showed a good precision and excellent correlations with DPC-CLIA; therefore, TIA could be used in the routine laboratory to determine a quantitative analysis of beta 2M.

Expressed genes related to adolescent idiopathic scoliosis in spinal facet

To construct a subtractive cDNA library from the spinal facets of adolescent idiopathic scoliosis (AIS) patient with suppression subtractive hybridization (SSH) technique and clone differentially expressed genes related to AIS in spinal facet. mRNA was isolated separately from the convex side and concave side apical facets of an adolescent idiopathic scoliosis patient. Moreover, single-strand (ss) and double-strand (ds) cDNAs were synthesized in turn using SMART PCR cDNA synthesis technology. (ds) cDNAs then were digested with Rsa I and divided into two groups, and ligated to the specific adaptor 1 and adaptor 2R, respectively. After cDNAs were hybridized with each other twice and underwent two rounds of nested PCR, the PCR products were ligated with pDrive Cloning Vectors to set up the subtractive library. Sequence analysis was performed and the acquired data were aligned against the GeneBank nucleotide database. Furthermore, the spinal facets of 11 IS patients were collected. The techniques of immunohistochemistry and in situ hybridization were adopted in order to approve the gene expression difference. The images of immunohistochemistry and in situ hybridization were input to the image analysis system and were analyzed semi-quantitatively. A cDNA subtractive library of AIS in spinal facet was set up successfully with high subtractive efficiency. Beta2 Microglobulin (beta 2M) and calgranulin A (S100A8) were identified as highly differentially expressed genes in this study. All results confirm the effectiveness and sensitivity of SSH in detecting differentially expressed genes from a small amount of clinical samples. Information about such alterations in gene expression can be useful for elucidating the genetic events in the development of AIS.

Influence of breast carcinoma cells on normal endothelial cells: experimental study with a co-culture system

To study the influence of breast carcinoma cells on normal endothelial cells. Human endothelial cells were isolated from umbilical cord blood. Medium Z-MCF-7-EC was established and was used to co-culture the normal endothelium cells (ECs) and human breast cancer cells of the line MCF-7. Normal endothelial cells cultured by itself were used as control. Light microscopy and transmission electron microscopy were used to observe the morphology of the 2 kinds of endothelial cells. Expression of the genes ESM, IGFBP-3, alphavbeta3, VE-C, and Tie-2-2 was analyzed by semi-quantitative RT-PCR using a house-keeping gene beta(2m) as inner reference gene. The ECs co-cultured with MCF-7 breast cancer cells were abnormal in shape with increased size of nucleus and nucleolus, increased size ratio of nuclear to nucleoplasm, increased depth of surface fenestration, loosed and distorted endoplasm, increased size of cell-cell junctions, decreased number of surface microvilli, and tubules formed by ECs. The expression values of the genes ESM, IGFBP-3, alphavbeta3, VE-C, and Tie-2-2 in the ECs co-cultured with MCF-7 breast cancer cells were all up-regulated in comparison with those in the controls (P < 0.01, P < 0.05, P < 0.01, P < 0.01, and P < 0.05 respectively). Breast cancer cells promote formation of new vessels with endothelial cells different from the normal ECs in character and behavior.

A Comparison of Bicarbonate Hemodialysis, Hemodiafiltration, and Acetate‐free Biofiltration on Cytokine Production

Acetate-free biofiltration (AFB) is a special hemodiafiltration (HDF) modality performed with a base-free dialysate and simultaneous injection of non-pyrogenic sodium bicarbonate solution. The purpose of this study was to investigate the difference of cytokine production by conventional bicarbonate hemodialysis (BCD), standard HDF and AFB in the same patients. Eight stable hemodialysis patients were treated in random order with BCD, HDF and AFB every 4 weeks. The production of interleukin-1 beta (IL-1 beta) and interleukin-1 receptor antagonist (IL-1Ra) by peripheral blood mononuclear cells (PBMC) was investigated without stimulation and with stimulation by a small amount of endotoxin (ET)-contaminated beta 2-microglobulin (beta 2M) and lipopolysaccharide (LPS) before and after dialysis treatment in the last sessions during all periods. To serve as controls, 14 healthy volunteers participated in this study. In spontaneous IL-1Ra production, the values of before and after AFB were not significantly different from that of the controls, and the values of before and after BCD and before HDF were significantly higher than that of the controls. In LPS-stimulated PBMC, IL-1 beta production before and after AFB was not significantly different from that of the controls, and before and after BCD and HDF was significantly higher than that of the controls. In ET-contaminated beta 2M-stimulated PBMC, IL-1 beta production before and after AFB was not significantly different compared to the controls, and the production was significantly lower than that before and after BCD and HDF. In addition, IL-1Ra production after AFB was not significantly different from the controls, and the production was significantly lower than that before and after BCD and HDF. It was concluded that a lower cytokine production by AFB may have the effect of preventing dialysis-related complications.

A single viral protein HCMV US2 affects antigen presentation and intracellular iron homeostasis by degradation of classical HLA class I and HFE molecules

HFE is a nonclassical class I molecule that associates with beta 2-microglobulin (beta 2m) and with the transferrin receptor. HFE accumulates in transferrin-containing endosomes, and its overexpression in human cell lines correlates with decreased transferrin receptor (TFR)-mediated iron uptake and decreased intracellular iron pools. A mutation that interferes with proper folding and assembly of HFE complexes results in a severe iron-overload disease hereditary hemochromatosis. We previously suggested that viruses could also interfere with iron metabolism through the production of proteins that inactivate HFE, similarly to classical class I proteins. In particular, we demonstrated in a transient expression system that human cytomegalovirus (HCMV) US2 targeted HFE for proteasomal degradation. Here we demonstrate that the stable expression of HCMV US2 in HEK 293 cells constitutively expressing HFE leads to loss of HFE expression both intracellularly and on the cell surface, and the significant reduction of classical class I expression. Both HFE and classical class I molecules are targeted to degradation via a similar pathway. This HCMV US2-mediated degradation of HFE leads to increased intracellular iron pools as indicated by reduced synthesis of TfR and increased ferritin synthesis. Whether this interference with regulation of iron metabolism potentiates viral replication and/or promotes damage of HCMV-infected tissues remains to be determined. Nevertheless, the deleterious effect of US2 on the expression of HFE and classical class I major histo-compatibility complexes (MHC) provides HCMV with an efficient tool for altering cellular metabolic functions, as well as supporting the escape of virus-infected cells from cytotoxic T lymphocyte (CTL)-mediated immune responses.

Beta 2 microglobulin knockout mice are resistant to lethal intraabdominal sepsis.

beta 2 microglobulin knockout (beta2M-/-) mice lack CD8+ T and natural killer T cells. We hypothesized that beta 2M-/- mice are resistant to lethal intraabdominal sepsis. To test this hypothesis, mortality, cytokine production, and physiologic function were assessed in beta 2M-/- mice during sepsis caused by cecal ligation and puncture (CLP). beta 2M-/- mice survived significantly longer than wild-type mice after CLP but ultimately exhibited 100% mortality. Treatment of beta 2M-/- mice with anti-asialoGM1 to deplete natural killer cells conferred greater than 70% long-term survival. Compared with wild-type mice, beta 2M-/- mice treated with anti-asialoGM1 produced decreased amounts of proinflammatory cytokines and did not exhibit hypothermia or metabolic acidosis after CLP. Adoptive transfer of CD8+ T and natural killer cells into beta 2M-/- mice treated with anti-asialoGM1 re-established CLP-induced mortality. CD8 knockout mice treated with anti-asialoGM1, which are specifically deficient in CD8+ T and natural killer cells, exhibited 40% long-term survival after CLP. Furthermore, treatment of wild-type mice with antibodies to CD8 and asialoGM1 conferred a significant survival benefit compared with wild-type mice treated with nonspecific IgG. These findings demonstrate that beta 2M-/- mice treated with anti-asialoGM1 are resistant to CLP-induced mortality and that depletion of CD8+ T and natural killer cells largely accounts for the survival benefit observed in these mice.

Serum E-selectin and beta 2-microglobulin levels in Behçet's disease.

Behçet's disease is a systemic vasculitis of unknown aetiology. Endothelial cell injury plays an important role in the pathogenesis and immunopathology of systemic vasculitises, but an immunopathogenic basis is also probable in Behçet's disease. E-selectin is an indicator of endothelial injury, and beta 2-microglobulin (beta 2M) is increased in immunological disorders. The serum concentrations of these two markers were determined in 40 patients with active Behçet's disease and 40 healthy controls. E-selectin was determined by enzyme-linked immunosorbent assay and beta 2M was determined by the nephelometric method. The mean (+/- SD) serum concentration of E-selectin was 122.13 +/- 62.32 ng/ml and that of beta 2M was 0.31 +/- 0.05 mg/dl. Both concentrations were statistically significantly increased in patients with Behçet's disease compared with controls. More comprehensive studies are needed to determine whether these parameters are useful indicators of the activity of Behçet's disease.

Characterization of CD1d in mucosal immune function: an immunotherapeutic target for inflammatory bowel disease.

In addition to the classical MHC class I and class II molecules, human intestinal epithelial cells also express nonclassical MHC class I-like molecules on their cell surface. CD1d is a non-polymorphic MHC-like molecule whose expression is mainly localized to the epithelial cells of the gastrointestinal tract. The biochemical structure of CD1d on intestinal epithelial cells (IECs) exists in two forms: a 37-kD nonglycosylated, beta 2-microglobulin (beta 2M) independent and a 48-kD glycosylated, beta 2M dependent form. Immunolocalization studies suggest that the 37-kD nonglycosylated form of CD1d is limited to the apical cell surface whereas the 48-50-kD glycosylated, beta 2M dependent form of CD1d is expressed both on the apical and the basolateral surfaces. The beta 2M association with CD1d seems to be important in regulating the pattern of glycosylation and the localization of CD1d within the cell based upon studies of the structure of CD1d in a transfected model cell line and in polarized epithelial cell monolayers. The functional role of intestinal CD1d remains unknown. However, based upon in vitro studies of the antigens presented by human CD1d and mouse CD1d, CD1d expressed on IECs likely presents a very hydrophobic glycolipid molecule possibly from the cell wall of bacteria or host cells. The processed-lipid antigen presented by CD1d may then involve a yet-to-be-identified subpopulation of the resident, oligoclonal alpha beta TCR CD8+ intestinal intraepithelial lymphocyte (iIEL) T cells. Subsequently, these T cells would be very important in regulating the local immune response by producing cytokines and recruiting other immune modulating cells to destroy infected cells, regenerate normal IECs, and possibly downregulate activated T cells to maintain mucosal integrity.

Prognostic value of soluble intercellular adhesion molecule-1 (s-ICAM-1) in HIV-infected children.

Central events in the host defence system and immune-mediated damage are tightly regulated by cell adhesion molecules. Sera from 28 human immunodeficiency virus (HIV)-1 infected children divided into groups according to disease severity, six seroreverting (SR) children and 25 healthy controls were studied to detect the presence of soluble intercellular adhesion molecule-1 (s-ICAM-1). Soluble ICAM-1 levels were found to be significantly increased in HIV-infected children in comparison with SR children or healthy controls. Levels of soluble ICAM-1 were higher in patients with severe forms of HIV-infection than in those with a milder form of the disease. Significant differences in titers of s-ICAM-1 were recorded between SR children and HIV-infected children with mild disease or healthy controls. There was a significant correlation between s-ICAM-1 levels and the concentrations of beta 2 microglobulin (beta 2m) and, to a lesser extend, immunoglobulin A levels (IgA). Soluble ICAM-1 levels didn't change considerably in HIV-infected children in stable clinical conditions, independently of their clinical stage of the disease, during a follow-up period of 9-12 months. Conversely, s-ICAM-1 levels increased simultaneously with the appearance of new well-defined clinical disorders or decreased during the improvement of clinical conditions. A significant negative correlation was recorded between the titers of the s-ICAM-1 and the CD4(+) T-cell levels. These results suggest that the s-ICAM-1 might be another useful tool to evaluate disease progression.

Osteoarticular disorders of renal origin: disease-related and iatrogenic.

Osteoarticular disorders significantly limit the quality of long-term survival with chronic renal failure. beta 2M amyloidosis is a complication of chronic renal failure that has been recognized mostly in patients receiving long-term haemodialysis. Patients with beta 2M amyloidosis typically present with the triad of shoulder periarthritis, carpal tunnel syndrome, and flexor tenosynovitis of the hands. Other musculoskeletal manifestations of beta 2M amyloidosis include destructive spondyloarthropathy, cervico-occipital pseudotumours, bone cysts, and pathological fractures. At present, only renal transplantation may slow or halt the progession of beta 2M amyloidosis. Crystal-induced arthropathy, most commonly caused by basic calcium phosphate crystals, is an important cause of acute joint inflammation in the patient with renal failure. The incidence of bone and joint infection is increased in patients undergoing dialysis. Haemodialysis and peritoneal dialysis are also associated with an erosive or destructive arthropathy of finger joints, which is not explained by local amyloid deposition.