[Antibody levels of measles, rubella and mumps viruses in healthy population in Shanghai from 2010 to 2020]

Objective: To determine IgG antibody levels of measles, rubella, mumps in healthy population in Shanghai from 2010 to 2020 and analyze the trend of antibody changes in different age groups. Methods: 10 828 healthy people without measles, rubella and mumps in Shanghai were included in the study from 2010 to 2020. Serum samples were collected from 12 age groups, and the serum IgG antibody of measles, rubella and mumps were detected by ELISA. The difference of antibody positive rates and antibody levels were analyzed. Results: The median age M (Q₁, Q₃) of 10 828 objects were 8 years old (9 months old, 20 years old). Males accounted for 48.34% (5 234/10 828) and females accounted for 50.92% (5 514/10 828). Unknown gender information accounted for 0.74% (80/10 828), and 27.03% (2 927/10 828) of participants had unknown MMR immunization history. The total positive rates of measles, rubella and mumps IgG antibody were 76.78%, 64.46% and 64.29% and their GMCs were 541.45 mIU/ml, 31.76 IU/ml and 133.73 U/ml respectively. There were significant differences in serum IgG antibody GMC of measles, rubella and mumps in each year (F_measles=180.74, P<0.001; F_rubella=189.95, P<0.001; F_mumps=122.40, P<0.001). The positive rate of measles antibody was higher than that of rubella and mumps, and the difference was statistically significant (χ²=518.09, P<0.001). Conclusion: The level of measles IgG antibody in healthy people in Shanghai is higher, while the level of rubella and mumps IgG antibody is slightly lower.

Atomic structure, tensile property, and dislocation behavior of Fe-W interfaces from molecular dynamics simulation

Molecular dynamic simulations based on a recently constructed potential reveal that quasi-repeating patterns could appear in both Fe(110)/W(110) and W(110)/Fe(110) interfaces, and that three kinds of atomic displacements of Fe atoms because of the Fe-W interaction intrinsically bring about the interesting quasi-repeating patterns of the Fe-W interfaces. It is also found that the Fe-W interface becomes more brittle with less critical strains under tensile loading than pure Fe or W, which is fundamentally attributed to the movement of the interface dislocations as a result of the lattice mismatch between Fe and W. Interestingly, the dislocation loops could be formed in the Fe-W interface under tensile loading due to the pinning of the100edge dislocations by the edge dislocations of1/2111, whereas no dislocation loop would be generated in pure Fe or W.

Strain-stress relationship and dislocation evolution of W-Cu bilayers from a constructed n-body W-Cu potential

An n-body W-Cu potential is constructed under the framework of the embedded-atom method by means of a proposed function of the cross potential. This W-Cu potential is realistic to reproduce mechanical property and structural stability of WCu solid solutions within the entire composition range, and has better performances than the three W-Cu potentials already published in the literature. Based on this W-Cu potential, molecular dynamics simulation is conducted to reveal the mechanical property and dislocation evolution of the bilayer structure between pure W and W_0.7Cu_0.3 solid solution. It is found that the formation of the interface improves the strength of the W_0.7Cu_0.3 solid solutions along tensile loading perpendicular to the interface, as the interface impedes the evolution of the dislocation lines from the W_0.7Cu_0.3 solid solutions to the W part. Simulation also reveals that the interface has an important effect to significantly reduce the tensile strength and critical strain of W along the tensile loading parallel to the interface, which is intrinsically due to the slip of the edge or screw dislocations at low strains as a result of the lattice mismatch.

[Phenotype and mechanism of inducible ppp2r1a knockout mouse model]

Objective: Investigate the effects of inducible ppp2r1a knockout on main physiological function in adult mice and study the mechanism. Methods: Ppp2r1a(flox/flox) mice and CAGG-CreER mice were hybridized to obtain 20 CAGG-CreER ppp2r1a(flox/flox) and 20 mice in homozygous group. Two groups of mice were divided into 4 groups respectively, finally we got 8 groups with 5 mice in each group. Tamoxifen was injected intraperitoneally to acquire inducible ppp2r1a knockout mice. The knockout efficiency of PP2A Aα in vital organs was measured by Western blot. At 0, 2, 4 and 6 days after injection, we measured body weight, histopathological change, peripheral blood cell counts and blood biochemical. Real-time PCR was performed to measure expression of liver glucolipid metabolism genes. Results: After tamoxifen injection for 6 days, the knockout efficiency of PP2A Aα in vital organs was 35%, 12%, 15%, 60%, 69% and 72%, respectively in heart, liver, spleen, lung, kidney and brain. After tamoxifen injection for 6 days, the weight of homozygous mice was lower than that of wild type mice, with values of (17.42±1.76) g and (21.69±1.82) g, respectively (P<0.05). Moreover, the activity level, abdominal and renal fat were significantly decreased in homozygous mice. Homozygous mice survived no more than 7 days. Compared with wild type mice, the organ coefficient of spleen of homozygous mice was decreased at the 6th day, with values of (0.59±0.10)% and (0.36±0.05)% respectively (P<0.05). Obvious spleen atrophy and marked decrease of nucleated cells were showed by performing HE staining. Tunel staining revealed increased apoptosis ratio of splenic lymphocytes in homozygous mice. The levels of alanine aminotransferase (ALT) and aspartate transaminase (AST) of homozygous mice were higher than wild type mice (P<0.05). The values of ALT and AST in homozygous mice were (153.68±62.80) U/L and (193.2±44.28) U/L. The corresponding values in wild type mice were (41.02±12.91) U/L and (69.40±9.55) U/L. The above results indicated that ppp2r1a knockout caused liver damage. Blood sugar level of homozygous mice was lower than in wild type mice (P<0.05), with values of (4.20±1.99) mmol/L and (8.88±0.65) mmol/L respectively. Plasma total cholesterol (TC), high density lipoprotein (HDL) and β-hydroxybutyric acid (β-HB) level of homozygous mice were higher than those of wild type mice (P<0.05). The values of TC, HDL and β-HB in homozygous mice were (3.12±0.39), (1.53±0.38) and (2.49±0.89) mmol/L. The corresponding values in wild type mice were (1.69±0.92), (0.78±0.50) and (0.45±0.30) mmol/L respectively. The above results indicated that ppp2r1a loss interfered glucose and cholesterol metabolism. In addition, we also found that the white blood cell count (WBC) and lymphocyte count (LYM) of homozygous mice were lower than in wild type mice (P<0.05). The values of WBC and LYM in homozygous mice were (1.88±0.89)×10(9)/L and (0.92±0.37)×10(9)/L respectively. The corresponding values in wild type mice were (3.91±0.80)×10(9)/L and (2.74±0.52)×10(9)/L respectively. The mRNA levels of glucose-6-phosphatase (G6P) and phosphoenolpyruvate carboxykinase (PEPCK) of homozygous were lower than wild type mice (P<0.05). The fold change of G6P and PEPCK in homozygous mice was 0.46±0.11 and 0.72±0.07 respectively. The corresponding fold change in wild type mice was 1.02±0.07 and 1.02±0.06 respectively. Conclusion: Whole body ppp2r1a is essential for the survival of adult mice, due to the important role in maintaining the metabolism of glucose and cholesterol of liver.

Independent and interactive effects of incremental heat strain, orthostatic stress, and mild hypohydration on cerebral perfusion

The purpose of this study was to identify the dose-dependent effects of heat strain and orthostasis [via lower body negative pressure (LBNP)], with and without mild hypohydration, on systemic function and cerebral perfusion. Eleven men (means ± SD: 27 ± 7 y; body mass 77 ± 6 kg), resting supine in a water-perfused suit, underwent progressive passive heating [0.5°C increments in core temperature (T_c; esophageal to +2.0°C)] while euhydrated (EUH) or hypohydrated (HYPO; 1.5-2% body mass deficit). At each thermal state, mean cerebral artery blood velocity (MCAv_mean; transcranial Doppler), partial pressure of end-tidal carbon dioxide ([Formula: see text]), heart rate (HR) and mean arterial blood pressure (MAP; photoplethysmography) were measured continuously during LBNP (0, -15, -30, and -45 mmHg). Four subjects became intolerant before +2.0°C T_c, unrelated to hydration status. Without LBNP, decreases in [Formula: see text] accounted fully for reductions in MCAv_mean across all T_c. With LBNP at heat tolerance (+1.5 or +2.0°C), [Formula: see text] accounted for 69 ± 25% of the change in MCAv_mean. The HYPO condition did not affect MCAv_mean or any cardiovascular variables during combined LBNP and passive heat stress (all P > 0.13). These findings indicate that hypocapnia accounted fully for the reduction in MCAv_mean when passively heat stressed in the absence of LBNP and for two- thirds of the reduction when at heat tolerance combined with LBNP. Furthermore, when elevations in T_c are matched, mild hypohydration does not influence cerebrovascular or cardiovascular responses to LBNP, even when stressed by a combination of hyperthermia and LBNP.

[The relationship between histone H3Ser10 phosphorylation and DNA damage in periphery blood lymphocytes of polycyclic aromatic hydrocarbons exposed workers]

Objective: To investigate the effect of polycyclic aromatic hydrocarbons (PAHs) exposure on the level of histone H3Ser10 phosphorylation (p-H3S10) and DNA damage degree in peripheral blood lymphocyte (PBLCs). Method: 75 coke oven workers from Benxi steel plant in Liaoning Province of China (PAHs-exposed group) and local 50 hot rolling workers (control group) were recruited in this study with age, working years, labor intensity and high temperature for matching factors using cluster sampling method in 2014. HPLC-fluorescence was performed to determine the level of urinary 1-hydroxypyrene (1-OHP), DNA damage and specific histone modification were measured in PBLCs of the subjects through comet assay and ELISA assay, respectively. Linear regression model analysis was used to analyze the differences among PAHs exposure, DNA damage and p-H3S10 level in two groups. The Mediation analysis was used to analyze the regulated relationships between urinary 1-OHP, DNA damage and histone modification through the bootstrap method. Results: Age of the control and the exposed group were (45.32±8.32) and (43.87±5.67) years old (P=0.284). The concentration of urinary 1-OHP, OTM value, Tail DNA% and p-H3S10 level in exposure group were higher than that in control group, while the M (P(5)-P(95)) of p-H3S10 levels in control and exposed group were 2.21 (0.68-4.71), 4.54 (1.85-23.91) (P<0.001). The degree p-H3S10 level was increased after the subgroups which were (2.59±1.19)%, (3.24±2.81)%, (5.55±3.25)%, (8.77±7.84)%, respectively, divided by quantitated 1-OHP concentration as P(0)-P(25), P(26)-P(50), P(51)-P(75) and P(76)-P(100) (P<0.001). We also found the correlations between urinary 1-OHP and p-H3S10 level or OTM value or Tail DNA%, β (95%CI) were 0.264 (0.167-0.360), 0.500 (0.299-0.702), and 0.510 (0.384-0.671), respectively (P<0.001). Similar result was also observed between p-H3S10 level and OTM value or Tail DNA%, β (95%CI) were 0.149 (0.073-0.226) and 0.220 (0.132-0.308) (P<0.001). Moreover, the mediation effect value of DNA damage on PAHs induced p-H3S10 alteration was 0.054(P=0.040). Conclusion: The results suggested that PAHs exposure could induce DNA damage and an increase in histone H3Ser10 phosphorylation in PBLCs. Particularly, the alteration of H3S10 phosphorylation may play an important role in regulating cell DNA damage repair.

A fluorescent probe for H2S in vivo with fast response and high sensitivity

In this work, a fluorescent probe has been designed and synthesized that could be applied for monitoring and imaging exogenous or endogenous H₂S in live MCF-7 cells and in live mice with the fastest response.

Experimental autoimmunity to thyrotropin receptor

Since the cloning of a full length cDNA encoding the thyrotropin receptor (TSHr), several laboratories have been actively trying to develop an optimal animal model to understand the pathogenesis of TSHr mediated autoimmune diseases and have made considerable progress. To date, results from our laboratory have indicated that the nature of the antigen, and the adjuvant used for immunization, immunogenetic background of the animal and fine specificities of antibodies elicited might play an important role in determining the qualitative nature of the antibody response. Although an ideal animal model for either Graves' disease or primary myxedema is not yet available, ongoing studies in our laboratory and elsewhere hold promise for establishing animal models for various TSHr mediated autoimmune diseases in the near future.

Expression and characterization of a Rana pipiens amelogenin protein

Amelogenin, the major protein of developing enamel matrix, controls enamel crystal growth via unique supermolecular features. While much has been contributed to our understanding of mammalian amelogenin function, little is known about how amelogenin and its unique physico-chemical features have evolved among vertebrates. Here we report, for the first time, amphibian amelogenin recombinant protein expression and characterization in Rana pipiens. In order to characterize R. pipiens amelogenin, the newly discovered amelogenin coding sequence was amplified, subcloned, and expressed in Eshcerichia coli. Our newly generated R. pipiens amelogenin-specific antisera resolved a major 19-kDa band on western blots of frog tooth extracts and revealed an enamel organ tissue-specific localization pattern using immunohistochemistry. Using mass spectroscopy, a single major compound with a molecular weight of 21.6 kDa was detected, which corresponded to the amino acid sequence-based molecular weight prediction of the His fusion recombinant protein. Dynamic light scattering studies resolved 41-nm radius subunits compared with 14-nm radius subunits from mouse recombinant amelogenin controls. Transmission electron microscopy revealed defined spherical subunits in R. pipiens matrix self-assembly in contrast with a homogeneous 'stippled' matrix in mouse amelogenin matrix self-assembly. Our data suggest that R. pipiens amelogenin is distinguished from mammalian amelogenins by a number of unique physico-chemical properties which may be related to specific modes of crystal formation in frog enamel.

Adjuvant effects of cholera toxin b subunit on immune response to recombinant thyrotropin receptor in mice

We had previously shown that BALB/c mice immunized with the extracellular domain of human thyrotropin receptor (ETSHR) developed moderate hyperthyroxinemia. The antibody responses in these mice were predominantly of the IgG1 subclass. Since cholera toxin B subunit (CT-B) has direct effects on the thyroid, and is known to activate B lymphocytes and cause enhanced IgG1 production, we tested the ability of CT-B to modulate the antibody response to ETSHR. CT-B is unique in that it not only elicits a strong immune response to itself, but more importantly, when given with other antigens acts as a potent adjuvant. In the present study, BALB/c mice given ETSHR with CFA or CT-B via ip route showed higher titers of antibodies to ETSHR when compared to mice similarly immunized with ETSHR alone, or with IFA. Antibodies in ETSHR+CT-B immunized mice were mostly of the IgG1 subclass and reacted predominantly with ETSHR peptides 1 (aa 22-41), 21 (aa 322-341), and 23 (352-371). In contrast, animals immunized with ETSHR+CFA showed IgG1, IgG2a and IgG2b responses and reacted with peptides 1 and 21. Furthermore, mice immunized with ETSHR along with CT-B showed significantly higher levels of thyrotropin (TSH) binding inhibitory immunoglobulins (TBII) compared to those that did not receive CT-B. None of the mice immunized with a control antigen showed antibody response to ETSHR. These results suggested that CT-B could enhance and modulate immune response to ETSHR.

BALB/c mice produce blister-causing antibodies upon immunization with a recombinant human desmoglein 3

Pemphigus vulgaris (PV) is an Ab-mediated autoimmune blistering disease of mucotaneous surfaces. Over 95% of the patients with PV express DR4 or DRw6, and the disease is characterized by the presence of autoantibodies directed against desmoglein 3 (Dsg 3), a protein expressed on keratinocytes. An appropriate animal model is required to understand immunoregulation and to address the role of immunogenetic components in the production of pathogenic Abs that are characteristic of PV. Therefore, we turned to the development of a mouse model. Four strains of female mice (BALB/c, DBA/1, SJL/J, and HRS/J) were screened for their ability to produce pathogenic anti-Dsg 3 Abs. We demonstrated that only BALB/c mice immunized with a full-length Dsg 3 can produce pathogenic Abs capable of causing acantholysis of human foreskin in culture and blistering in neonatal mice. This observation suggested that either H-2d or the BALB background contains the immunogenetic makeup necessary for the production of pathogenic anti-Dsg 3 Abs. No correlation was noted between a given isotype and the pathogenic potential of autoantibodies from different strains of mice. Similarly, the pattern of reactivity of Abs with a panel of 46 synthetic peptides that span the entire Dsg 3 failed to reveal any association between binding specificity and the pathogenic potential, and suggested that pathogenic Abs might recognize conformational epitopes. Moreover, our studies showed that the epitopes recognized by pathogenic Abs are contained within the extracellular Dsg 3.

Comparison of immune responses to extracellular domains of mouse and human thyrotropin receptor

The mouse and human thyrotropin receptors show greater than 87% homology in their amino acid sequences. However, glycosylated extracellular domains of mouse (mET-gp) and human (hET-gp) thyrotropin receptors showed differences in their ability to react with patient autoantibodies to thyrotropin receptor (TSHR). To test for potential differences in their immunogenicity, we immunized BALB/c mice with either gel pure non-glycosylated ectodomain of human TSHR (ETSHR II), or hET-gp (hET-gp III), or mET-gp (mET-gp III). Alternatively, mice were primed with gel pure hET-gp or mET-gp and subsequently immunized with insect cells expressing hET-gp (hET-gp II) or mET-gp (mET-gp II) respectively. All groups of mice immunized with TSHR developed high titers of antibodies against the respective immunogens. As shown earlier, sera obtained from mice immunized with ETSHR showed strong reactivity to peptide 1 (aa 22-41) and weak reactivity to peptides 23 (aa 352-371), 24 (aa 367-386), 25 (aa 382-401), and 26 (aa 397-415). Mice immunized with hET-gp or mET-gp showed comparable titers to peptides 1 and 23 and lower reactivity to other peptides. Mice immunized with hET-gp showed higher TBII reactivity (52.2%) compared to mice immunized with either ETSHR (20.9%) or mET-gp (34.5%). Peptides from the C-terminal region of ETSHR could neutralize the TBII activities of sera from mice immunized with ETSHR or hET-gp but not mET-gp. Compared to corresponding control mice, T4 levels in mET-gp II mice were only marginally higher. These data suggested that outcome of immunization with mouse ETSHR is comparable to that seen after immunization with human ETSHR.

Thyrotropin-receptor-mediated diseases: a paradigm for receptor autoimmunity

Autoantibodies to the thyrotropin receptor (TSHR) can act as thyrotropin agonists or antagonists, or can cause thyroid hypertrophy. Neither the autoantibody-binding sites on the TSHR nor the intracellular mechanisms by which the autoantibodies mediate their diverse functional effects are completely understood. This article reviews how cloning of the TSHR has contributed to our understanding of its structure and function, and has allowed induction of experimental autoimmunity to the TSHR.

Induction of blister-causing antibodies by a recombinant full-length, but not the extracellular, domain of the pemphigus vulgaris antigen (desmoglein 3)

Pemphigus vulgaris (PV) is mediated by autoantibodies to desmoglein 3, the pemphigus vulgaris antigen (PVA). PVA and an extracellular domain of PVA-Ig fusion protein (PV-Ig) can completely adsorb the blister-causing Abs from PV patient sera, suggesting that the extracellular segment of PVA might be sufficient to induce pathogenic Abs. To test this, we immunized rabbits with either PVA or its extracellular domain (EPVA) expressed in insect cells in our laboratory. When Igs were passively transferred from these rabbits into neonatal mice, anti-PVA, but not the anti-EPVA, induced blisters. To understand the basis for their differential pathogenic effects, we examined the properties of these sera. Both sera showed comparable ELISA titers and indirect immunofluorescence reactivity against monkey esophagus, a source of native PVA. Moreover, EPVA, like PVA adsorbed blister-causing Abs from sera of PV patients and rabbits immunized with PVA. In contrast, when IgG preparations were incubated with fura-2-AM (acetyloxymethyl ester)-loaded human keratinocytes in culture, only IgG from anti-PVA serum induced intracellular calcium mobilization. These data showed that PVA but not EPVA can elicit Abs that induced blisters in neonatal mice and mediate intracellular signaling through calcium mobilization.

Induction of blister-causing antibodies by a recombinant full-length, but not the extracellular, domain of the pemphigus vulgaris antigen (desmoglein 3)

Pemphigus vulgaris (PV) is mediated by autoantibodies to desmoglein 3, the pemphigus vulgaris antigen (PVA). PVA and an extracellular domain of PVA-Ig fusion protein (PV-Ig) can completely adsorb the blister-causing Abs from PV patient sera, suggesting that the extracellular segment of PVA might be sufficient to induce pathogenic Abs. To test this, we immunized rabbits with either PVA or its extracellular domain (EPVA) expressed in insect cells in our laboratory. When Igs were passively transferred from these rabbits into neonatal mice, anti-PVA, but not the anti-EPVA, induced blisters. To understand the basis for their differential pathogenic effects, we examined the properties of these sera. Both sera showed comparable ELISA titers and indirect immunofluorescence reactivity against monkey esophagus, a source of native PVA. Moreover, EPVA, like PVA adsorbed blister-causing Abs from sera of PV patients and rabbits immunized with PVA. In contrast, when IgG preparations were incubated with fura-2-AM (acetyloxymethyl ester)-loaded human keratinocytes in culture, only IgG from anti-PVA serum induced intracellular calcium mobilization. These data showed that PVA but not EPVA can elicit Abs that induced blisters in neonatal mice and mediate intracellular signaling through calcium mobilization.

Purification and characterization of a recombinant human thyroid peroxidase expressed in insect cells

Thyroid peroxidase (TPO) is an essential enzyme for thyroid hormone biosynthesis and is an autoantigen against which antibodies are found in a number of autoimmune thyroid disorders. Large quantities of pure TPO are essential for understanding its structure and role in normal thyroid function and thyroid diseases. In this study, we describe the production of human TPO (hTPO) using a baculovirus expression vector in insect cells. TPO was sequentially extracted from insect cells using various buffers and the protein was purified to homogeneity on a C4 reversed-phase semipreparative column using high-performance liquid chromatography. The purified protein was identified as hTPO by enzyme-linked immunosorbent assay, Western blot, and amino acid sequence analyses. Carbohydrate analysis of the recombinant hTPO showed that the protein is glycosylated and mannose is the major oligosaccharide. We have extended the carbohydrate analysis by establishing the occurrence of N-acetyl galactosamine which suggested that the recombinant hTPO might contain O-glycosyl moieties. Purified hTPO reacted specifically with sera from patients with Hashimoto's thyroiditis. Crude as well as purified hTPO did not show any enzymatic activity when produced in Sf9 insect cells grown in serum free medium. In contrast, hTPO produced in the presence of 10% fetal bovine serum containing 1 microgram/ml of haematin was enzymatically active. However, the enzymatic activity of the recombinant hTPO was lower than that often found with hTPO purified from thyroid tissue. Availability of purified hTPO in relatively large quantities should allow further structural and immunological studies.

Recombinant desmoglein 3 has the necessary epitopes to adsorb and induce blister-causing antibodies

The development of an animal model for studying the pathogenesis of pemphigus vulgaris (PV) has been hampered by the unavailability of the purified full-length autoantigen desmoglein 3 (Dsg 3).Therefore, we expressed Dsg 3 using a baculovirus expressed system. The expressed protein was identified as Dgs 3 by its reactivity with a pan-cadherin anti-serum, an anti-serum to a Dsg 3 synthetic peptide, or patient serum, and by amino-terminal sequencing. Carbohydrate analysis showed that recombinant Dsg 3 was glycosylated. While a majority of the recombinant protein was cell associated, by immunoprecipitation, some Dsg 3 was demonstrated in the medium. The Dgs 3 could adsorb out blister-causing antibodies from patient sera. Rabbit anti- Dsg 3 antibodies induced by the recombinant Dsg 3 showed specific binding to intercellular spaces of monkeys esophagus by indirect immunofluorescence. Moreover, these antibodies induced PV-like blisters in neonatal mice and weakly bound perilesional epidermis. Availability of large quantities of relatively pure Dsg 3 should now facilitate studies aimed at understanding Dsg 3 structure and pathogenesis of PV, with implications for developing specific immunotherapies.

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

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

High frequency of B cells capable of producing anti-thyrotropin receptor antibodies in patients with Graves' disease

Hyperthyroidism in Graves' disease (GD) is mediated by antibodies to the thyrotropin receptor (TSHr). Patients that go into remission show a decline in antibody titer. However, upon cessation of treatment with anti-thyroid drugs a significant proportion of patients relapse and TSHr antibodies (TSHrAb) are present in their circulation. This suggests that B cells capable of producing TSHrAb persist despite treatment. To determine the frequency of these cells, B cells from six patients with GD and four healthy controls were infected with Epstein-Barr virus and cultured in 96-well plates at varying cell concentrations. A higher frequency of B cells capable of producing TSHrAbs was detected in patients with GD, relative to normal controls. For example, at 2 x 10(5) cells per well, 100% of wells containing cells from either patients with GD or controls were positive for immunoglobulin (Ig) production. In contrast, 27% of the wells containing cells from Graves' patients, and only 3% from controls, were positive for TSHrAb. Higher titers of TSHrAbs were produced in cultures containing lymphocytes from patients with GD and were predominantly of IgG isotype. All patients with GD who had high thyrotropin binding inhibitory immunoglobulins also had higher frequencies of TSHr-specific B cells. These findings show that TSHrAb-producing B cells are present at a higher frequency in the peripheral circulation of patients with GD.

Induction of hyperthyroxinemia in BALB/C but not in several other strains of mice

We recently expressed the extracellular domain of the human TSHR (ETSHR) protein using a baculovirus expression system and purified it to homogeneity. The ETSHR specifically binds both TSH and antibodies to TSHR. In the present study, C57BL/6J, SJL/J, BALB/cJ and B10BR.SgSnJ mice were immunized with the recombinant ETSHR or an equivalent amount of control antigen. All strains of mice produced high titers of antibody against the TSHR protein which were capable of blocking the binding of TSH to native TSHR. However, only BALB/cJ mice showed significantly elevated levels of thyroxine in their sera compared to the control mice. Similarly, BALB/cJ mice primed with ETSHR and then challenged with thyroid membranes showed significantly elevated levels of thyroxine. In addition, histopathological examination of thyroid glands from affected mice showed morphological changes characterized by hydropic and subnuclear vacuolar changes and focal scalloping, with no apparent inflammation or glandular destruction. Moreover, mice with elevated thyroxine levels showed increased in vivo thyroidal uptake of 131Iodine. Together, these data suggest that BALB/cJ mice are susceptible to the induction of hyperthyroxinemia.

Heterogeneity in cellular and antibody responses against thyrotropin receptor in patients with Graves' disease detected using synthetic peptides

Graves' disease (GD) is characterized by the presence of autoantibodies to the thyrotropin receptor (TSHr). These antibodies bind to the TSHr and stimulate thyroid cells, thus causing hyperthyroidism. To understand the regulation of TSHr-specific immune responses in Graves' disease, it is important to evaluate the T-cell response in patients with GD against TSHr. In this study we used 11 different peptides that were derived from two regions (i.e. amino acid, AA 12-46 and 316-397) unique to the TSHr when compared to other glycoprotein hormone receptors, and which also have the highest predicted immunogenicity. We evaluated both lymphocyte proliferation as a measure of T-cell response and antibody binding to each of these peptides in nine patients with GD and eight healthy subjects. Patients with GD showed considerable lymphocyte proliferative and antibody responses against several of these peptides. There was considerable heterogeneity in immune responses amongst the patients. Moreover, our data suggested that several peptides contained both T cell and antibody reactive epitopes and might represent some of the highly immunogenic regions of the TSHr.

Dual mechanism of perturbation of thyrotropin-mediated activation of thyroid cells by antibodies to the thyrotropin receptor (TSHR) and TSHR-derived peptides

To further define the epitopes with which anti-TSH receptor (anti-TSHR) antibodies react and mediate their biological effects, we used antibodies against the extracellular domain of TSHR (ETSHR) protein and nine peptides derived from the ETSHR. Peptides were chosen based on their predicted immunogenicity as well as their uniqueness to the TSHR. Antipeptide antibodies showed varying degrees of reactivity against ETSHR, with antipeptide-2-(352-366) and -3A-(357-372) showing relatively stronger reactivity with the receptor. Antibodies were tested for their ability to stimulate thyroid cells and were found to be ineffective in causing both cAMP release and iodide uptake. However, anti-3A and anti-ETSHR showed blocking TSHR antibody (TSHRAb) activities of 76.9% and 79.7%, respectively, which were significantly different (P < 0.005) compared to that of preimmune serum. Anti-2 and -91 (AA 32-46) also showed blocking TSHRAb activities of 37.5% and 35.6%, respectively (P < 0.05). Antisera were also tested for their ability to block TSH binding to thyroid membranes in a RRA. Anti-ETSHR, but not any of the antipeptide antibodies, displayed TSH binding inhibitory immunoglobulin activity. These findings suggest that there might be different mechanisms that mediate blocking TSHR antibody activity. One mechanism involves the inhibition of TSH binding to the receptor, and the other probably involves a step subsequent to TSH binding.

Immunization of mice with Yersinia enterocolitica leads to the induction of antithyrotropin receptor antibodies

It is well established that autoimmune Graves' disease, which is characterized by hyperthyroidism, is mediated by autoantibodies to the thyrotropin receptor (TSHr). Although what initially triggers this autoantibody response is not known, a number of studies have suggested that Yersinia enterocolitica, an enterobacteria, could initiate the immune response against the TSHr. In this study, we produced antibodies against purified extracellular domain of human TSHr (ETSHr) and showed that anti-ETSHr antibodies reacted with envelope preparations from Y. enterocolitica. This reactivity was specifically blocked by preincubating sera with purified ETSHr. Moreover, antibodies reactive with ETSHr were induced by immunizing mice with Y. enterocolitica but not with Shigella flexneri SA100, Salmonella typhimurium TML, and Listeria monocytogenes. Anti-Y. enterocolitica antisera specifically reacted with the ETSHr protein and the reactivity could be blocked both by ETSHr and Y. enterocolitica envelope proteins. Our studies provide the first direct evidence that immunization with Y. enterocolitica can lead to the production of antibodies capable of reacting with TSHr and might provide the initial stimulus necessary for breakdown of self-tolerance to TSHr, eventually leading to the development of autoimmunity to TSHr.

Immunization of mice with Yersinia enterocolitica leads to the induction of antithyrotropin receptor antibodies

It is well established that autoimmune Graves' disease, which is characterized by hyperthyroidism, is mediated by autoantibodies to the thyrotropin receptor (TSHr). Although what initially triggers this autoantibody response is not known, a number of studies have suggested that Yersinia enterocolitica, an enterobacteria, could initiate the immune response against the TSHr. In this study, we produced antibodies against purified extracellular domain of human TSHr (ETSHr) and showed that anti-ETSHr antibodies reacted with envelope preparations from Y. enterocolitica. This reactivity was specifically blocked by preincubating sera with purified ETSHr. Moreover, antibodies reactive with ETSHr were induced by immunizing mice with Y. enterocolitica but not with Shigella flexneri SA100, Salmonella typhimurium TML, and Listeria monocytogenes. Anti-Y. enterocolitica antisera specifically reacted with the ETSHr protein and the reactivity could be blocked both by ETSHr and Y. enterocolitica envelope proteins. Our studies provide the first direct evidence that immunization with Y. enterocolitica can lead to the production of antibodies capable of reacting with TSHr and might provide the initial stimulus necessary for breakdown of self-tolerance to TSHr, eventually leading to the development of autoimmunity to TSHr.

Analysis of autoantibody reactivity in patients with Graves' disease using recombinant extracellular domain of the human thyrotropin receptor and synthetic peptides

Graves' disease is characterized by hyperthyroidism leading to enhanced production of thyroid hormones. Hyperthyroidism is primarily mediated by the binding of autoantibodies to the thyrotropin receptor (TSHr). In the past, either thyroid cells or thyroid membranes were used as a source of TSHr to detect anti-TSHr antibodies. Recently, we expressed the extracellular domain of the human TSHr (ETSHr) using the baculovirus expression system. In this study, we used ETSHr protein in an ELISA to detect anti-TSHr antibodies. Our data show that this assay can be used to analyze and quantitate isotype specific antibodies against the TSHr. To map immunogenic epitopes on the TSHr, we tested patients sera against synthetic peptides derived from two highly immunogenic regions (amino acid, AA 12-46 and 316-397) of the receptor. Although sera from patients with Graves' disease reacted with several peptides, they showed particularly strong reactivity against peptides from a relatively narrow region (i.e. AA 352-394) of the TSHr. The present study demonstrates the usefulness of the recombinant ETSHr to detect and characterize anti-TSHr antibodies in a simple and sensitive ELISA, and has lead to the identification of some of the immunoreactive epitopes on the TSHr.

Alterations in the functional characteristics of macrophages induced by hypercholesterolemia

Intimal accumulation of monocyte-derived lipid-filled macrophages is an important early event in diet-induced hypercholesterolemia. To better understand the functional alterations in macrophages in hypercholesterolemia, we determined several variables in rat peritoneal macrophages putatively associated with atherogenesis including adhesion to, spreading and locomotion on an endothelial monolayer, migration and phagocytic capacities, and superoxide anion (O2-) production. Compared with macrophages from normal rats (NM0s), macrophages from hypercholesterolemic rats (HM0s) revealed a higher rate of adherence to endothelial cells (ECs) and plastic with more extensive cytoplasmic spreading. Towards a chemoattractant of zymosan-activated serum, HM0s exhibited greater chemotactic migration and more prominent aggregation than NM0s. A computerized film analysis using time-lapse cinemicrophotography disclosed that HM0s moved faster on ECs; the average speed of HM0s was almost twice that of NM0s. HM0 phagocytic activity of fluorescent latex beads was significantly heightened (P less than 0.01). By contrast, there was no significant difference in O2- production between the two groups. These results indicate that hypercholesterolemia may initiate and accelerate the atherosclerotic process, at least in part, by modifying a number of functional properties of macrophages.

[Establishment of the vascular intimal model in vitro and its application in studying atherosclerosis]

An endothelial culture model in vitro mimicking the vascular intima in vivo was designed which was composed of an upper and a lower well separated by a layer of amnion membrane, and upon which endothelial cells (ECs) isolated from the human umbilical vein were cultured. The upper well, the subendothelial amnion, and the lower well were analogical to the vascular lumen, the subendothelial tissue and the extravascular space, respectively. In comparison with the ECs cultured on the plastic, dishes, ECs cultured on the amnion membrane maintained more morphologic features as in vivo and could be cultured for up to 15 days without apparent detachment. Monocytes, loaded in the upper wells, were able to adhere to the cytoplasmic membrane of ECs. Furthermore, with the presence of the chemotactic factor (fMLP) in the lower well, monocytes showed active migrating ability passing through the EC junctions. If LDL (100 micrograms/ml) was added in the media simultaneously, monocytes might be aggregated beneath the subendothelial space and some of them took an foamy appearance. In conclusion, the culture model is of value in the study of experimental inflammation and atherosclerosis.

Abnormalities in platelets and vascular endothelial cells induced by glycated lipoproteins

We studied the effects of glycated lipoproteins of low- and high-density (LDL and HDL) on platelets and vascular endothelial cells. After pretreatment for 5 minutes at 37 degrees C, the thrombin-induced synthesis of thromboxane B2 in washed platelets was significantly increased by glycated LDL as compared with native LDL (198.9 +/- 16.2 vs 90.3 +/- 29.4 ng/10(9) platelets, n = 8, p less than 0.01). Platelet aggregation was also increased by glycated LDL as compared with native LDL. After treatment with platelet-rich plasma for 5 hours at 37 degrees C, these values were suppressed by native HDL vs the control (buffer), but not by glycated HDL. Abnormalities in the release of 6-keto prostaglandin F1 alpha and lactate dehydrogenase from vascular endothelial cells were also induced by glycated LDL and/or HDL. These observations suggest that abnormalities induced in platelets and vascular endothelial cells by glycated lipoproteins may play an important role in the development of atherosclerosis in patients with diabetes mellitus.

Age-related decline in prostacyclin synthesis by human aortic endothelial cells. Qualitative and quantitative analysis

To investigate the functional alteration of human aortic endothelial cells with aging, prostacyclin synthesis was qualitatively and quantitatively examined. The endothelial cells of human aortas and umbilical veins or inferior vena cavae were immunohistochemically examined and found positive for prostacyclin, but the intensity of aortic endothelial cells from older subjects was low. In addition to the endothelial cells, smooth muscle cells in the thickened intima, not the media, of the aorta were also immunoreactive. Endothelial cells were successfully cultured from human aortas obtained from infants through aged subjects and were subdivided into three groups: young, middle, and old. Prostacyclin synthesis by endothelial cells from all types of blood vessels was extremely great at the primary culture, but decreased abruptly in the following subcultures. Among the aortic endothelial cells, the young group synthesized the largest amount of prostacyclin in a conventional culture condition, with synthesis progressively decreasing in the older groups. The in vitro prostacyclin biosynthesis was supported by the qualitative analysis on the tissue sections. These results indicate that prostacyclin synthesis of the aortic endothelial cells decreases with age, but intimal smooth muscle cells potentially have a back-up mechanism and substitute this synthesis to some extent. The decreased synthesis of prostacyclin with age may play an important role in the development and advancement of thrombosis and atherosclerosis.

Atherosclerosis- and age-related multinucleated variant endothelial cells in primary culture from human aorta

Endothelial cells were cultured from human aortas and inferior venae cavae of autopsied subjects ranging in age from infancy to 85 years. Endothelial cells in 32 of more than 100 attempted cultures were pure enough for evaluation. Emerged endothelial cells in primary culture were classified into two types: typical endothelium and variant endothelium. Typical endothelial cells were small, round to polygonal shaped, and were arranged uniformly. Their diameter ranged from 50 to 70 microns. Variant endothelial cells were larger, ranging from 100 to 200 microns in diameter, and giant endothelial cells measuring more than 250 microns in diameter were scattered among them. Variant endothelial cells were usually multinucleated and possessed endothelium-specific markers of vWF and Weibel-Palade bodies. No incorporation of [3H]thymidine was found in the nuclei of cultured variant endothelial cells. Although most cultured endothelial cells were of the typical type, variant endothelial cells were interspersed throughout the culture. The ratio of variant endothelial cells to typical cells correlated well with the severity of atherosclerosis, but less so with aging. The number of variant endothelial cells in cultures from inferior venae cavae was slight and constant throughout all age groups. The presence of multinucleated endothelial cells in in vivo aortas was confirmed by both scanning and transmission electron microscopy. They sometimes existed in colonies in the aortas from elderly subjects with intimal-thickened or advanced atherosclerotic lesions. These results indicate that variant endothelial cells were present in vivo and their ratio in primary culture reflected the in vivo population. It is likely that these cells were formed by adhesion of adjacent typical endothelial cells and that this process was affected more by atherosclerosis than by aging. Although it is not clear if the multinucleated variant cells were formed before the formation of atherosclerotic plaque or after the plaque formation, they will contribute to further development of atherosclerotic lesions, which in turn cause malfunction of the cell membrane. We suggest that there is a cyclic effect of these processes for multiplication of the variant endothelial cells and advancement of atherosclerotic lesions.

Atherosclerosis and macrophages

Atherosclerosis is undoubtedly a disease of many facets and in this review we have merely touched one angle of this issue. The best-established cause of the disease is hypercholesterolemia. Since the important role of macrophages in lipoprotein metabolism has been confirmed, current interest is focused on the role of macrophages in atherosclerosis. The origin and tissue distribution of foam cells have been discussed in detail, because they are the principal cells in the earliest lesions, the so-called fatty streaks. Once thought to be derived exclusively from smooth muscle cells, foam cells are now known to originate largely from monocytes that enter the intima and become transformed into macrophages. Exactly how monocytes are recruited and retained in the artery wall is not fully understood, but it is certain that the initial event involves adhesion to the endothelial surface followed by penetration under the influence of a chemotactic factor(s). Hypercholesterolemia contributes much to this phenomenon by affecting both monocyte-macrophages and endothelial cells. Intensive current research is increasing our understanding of the dynamic interaction between macrophages and both lipoproteins and vascular cells, and its immediate relevance to lesion formation. Closer scrutiny of the biology and molecular mechanism of the process of atherosclerosis may ultimately permit intervention in and slowing of the progress of this catastrophic human disease using new modalities.

Atherosclerosis and endothelium. Part II. Properties of aortic endothelial and smooth muscle cells cultured at various ambient pressures

Human aortic endothelial cells and smooth muscle cells (SMCs) were cultured at various ambient pressures and their properties were examined. The following results were obtained. 1) Endothelial cells were damaged when cultured at higher ambient pressures of 80 and 160 mmHg. This left cellular islands with central confluence showing no evident growth because of strong contact inhibition. 2) Aortic endothelial cells released high levels of prostacyclin, with significantly elevated release at higher ambient pressures, while intimal SMCs released a small amount of prostacyclin, and medial SMCs a minimal amount. 3) Prostacyclin release by aortic endothelial cells was inhibited in the presence of low concentrations of linoleic acid hydroperoxide (LAHO). Intimal and medial SMCs, however, showed no LAHO inhibition. These results indicate that the properties of both endothelial cells and SMCs vary according to in vitro and probably in vivo conditions. Their specific roles in the pathogenesis of various vascular disorders including atherosclerosis should be carefully considered.

Combined treatment of autoimmune MRL/Mp-lpr/lpr mice with cholera toxin plus irradiation. Combined treatment of autoimmune MRL/l mice

MRL/Mp-lpr/lpr (MRL/1) mice spontaneously develop autoimmune diseases like systemic lupus erythematosus (SLE) from 2 months of age, accompanied by massive lymphadenopathy. Such mice of 2 months of age were treated with 1 microgram cholera toxin (CT) every 7 days and/or with 400 rad of one-shot 60Co irradiation. CT treatment alone markedly improved nephritis as evaluated by proteinuria and moderately suppressed lymphadenopathy and anti-DNA antibody production, while irradiation alone prominently improved lymphadenopathy but showed little effect on both nephritis and anti-DNA antibody production. On the other hand, when mice were treated with the combination of CT plus irradiation, autoimmune nephritis as well as anti-DNA production and lymphadenopathy were almost completely inhibited. Taken together, each agent exerts the improvement effect at the different points from each other in an abnormal immunological circuit displayed in MRL/1 mice. This kind of combined treatment may be applicable to the clinical use for autoimmune diseases.

Drug-induced in vitro tolerance to allogeneic antigens. II. Further analysis of in vitro-tolerized spleen cells in a fully allogeneic murine combination

C3H/HeSlc (C3H, H-2k) spleen cells were made tolerant in vitro to C57BL/6CrSlc (B6, H-2b) at the cell-mediated cytotoxicity (CMC) level by in vitro stimulation for 48 hr with mitomycin C (MMC)-treated B6 spleen cells, and treatment with 5 micrograms/ml of 5-fluorouracil for a further 9 hr. These cells were given intraperitoneally to neonate (C3HxB6) F1 mice to examine whether these tolerized spleen cells would cause lethal graft-versus-host disease (GVHD). Despite the lack of CMC, the tolerized C3H spleen cells caused lethal GVHD in most of the neonate F1 mice. Evaluating from various immune parameters, it was evident that T cell populations responsible for IL-2 production, cytostasis, and delayed footpad reaction (DFR) were retained intact after in vitro tolerance induction, probably because of their less-proliferative characteristics in response to fully allogeneic antigen stimulation, and were considered to be responsible for lethal GVHD. Contribution of natural killer (NK) cells to lethal GVHD was not ruled out.

Treatment of autoimmune MRL/Mp-lpr/lpr mice with cholera toxin

The autoimmune manifestations of MRL/Mp-lpr/lpr(MRL/l), a murine model of systemic lupus erythematosus (SLE), were alleviated by administering 1 microgram cholera toxin (CT) every 14 days. The beneficial effects were: (i) significant prolongation of survival time, (ii) prevention of lymphadenopathy, (iii) improvement of T cell mitogenic responses and suppression of a B cell mitogenic response, (iv) decrease in serum anti-DNA and anti-Sm antibodies, (v) increase in IL-2 production by stimulation of spleen cells with concanavalin A (Con A). It is possible that CT may be effective for treatment of murine lupus nephritis by modulating polyclonal lymphocyte activation. This type of immunomodulation may pave the way toward treatment of lupus and other autoimmune diseases.

Drug-induced tolerance to allografts in mice. XII. The relationships between tolerance, chimerism, and graft-versus-host disease

When AKR/J Sea (AKR, H-2k) mice were primed i.v. with 1 X 10(8) viable spleen cells from naive C3H/He Slc (C3H, H-2k) mice and treated i.p. with 200 mg/kg cyclophosphamide (CP) 2 days later, a minimal degree of mixed chimerism associated with tolerance to C3H skin was established without graft-versus-host disease (GVHD) and maintained for at least one month. When AKR mice were primed i.v. with 1 X 10(8) viable spleen cells from C3H mice preimmunized i.v. 7 days earlier with 5 X 10(7) viable AKR spleen cells, and treated with 200 mg/kg CP, chimerism became exclusive, but lethal GVHD occurred in the AKR mice. Moreover, most of normal AKR mice primed with the preimmunized C3H spleen cells without CP died of GVHD. In contrast, in a major histocompatibility complex (MHC)-incompatible combination of AKR (H-2k)-C57BL/6 Cr Slc (B6, H-2b), mixed chimerism, tolerance to skin allografts, and GVHD were not observed, whether or not the mice had been treated with naive or preimmunized B6 spleen cells with or without CP.

Drug-induced tolerance to allografts in mice. X. Augmentation of split tolerance in murine combinations disparate at both H-2 and non-H-2 antigens by the use of spleen cells from donors preimmunized with recipient antigens

In a fully allogeneic murine combination of C3H/HeSlc (C3H) (H-2k) and C57BL/6CrSlc (B6) (H-2b), C3H mice were primed i.v. with 1 X 10(8) spleen cells from B6 mice preimmunized i.v. with 5 X 10(7) C3H spleen cells and then were given i.p. 200 mg/kg cyclophosphamide (CP) 2 days later (Im-B6-Sc plus CP group). The tolerant state in those recipient mice was compared with that in mice made tolerant conventionally with 1 X 10(8) naive B6 spleen cells plus 200 mg/kg CP (naive-B6-Sc plus CP group). B6 skin was rejected in an almost normal fashion in both the naive-B6-Sc plus CP group and the Im-B6-Sc plus CP group. However, EL4 tumor allografts (B6 origin) inoculated after complete rejection of B6 skin grafts were specifically accepted in both groups. Moreover, the tumor growth in the Im-B6-Sc plus CP group was faster than that in the naive-B6-Sc plus CP group. Mixed lymphocyte reaction, cytotoxic T lymphocyte activity, and antibody production against the tolerogen were depressed more profoundly in the Im-B6-Sc plus CP group than in the naive-B6-Sc plus CP group. These observations were consistent with the results from tumor allografting. The other immunological parameters examined in the present study, including helper T cell activity and delayed foot-pad reaction, were retained in the Im-B6-Sc plus CP group at the same levels as in the naive-B6-Sc plus CP group. These observations were consistent with the results from skin allografting. In conclusion, tumor allograft tolerance was made more profound by the use of spleen cells from donors preimmunized with recipient antigens as the tolerogen than by the use of naive spleen cells. However, skin allograft tolerance was not achieved at all by these same treatments. The contribution of graft-versus-host disease to this phenomenon was excluded by the chimeric analysis in AKR/JSea (H-2k) mice given the preimmunized (with AKR antigens) B6 spleen cells plus CP. These results strongly support the existence of a less proliferative lymphocyte population which does not evoke cell divisions to mature even after the strong stimulation with the preimmunized spleen cells and is resistant to tolerance induction.

Drug-induced tolerance to allografts in mice. IX. Establishment of complete chimerism by allogeneic spleen cell transplantation from donors made tolerant to H-2-identical recipients

Graft-versus-host reaction (GVH) after allogeneic spleen cell transplantation was completely suppressed in an H-2-matched murine combination (AKR/J Sea [H-2k]----lethally irradiated C3H/He Slc [H-2k]) by pretreatment of the donors with recipient spleen cell antigen plus cyclophosphamide (CP). Irradiated recipients receiving cells became chimeric. In contrast to the H-2 matched combination, lethal GVH reaction could not be prevented in an H-2-mismatched fully allogeneic combination (C57BL/6 Cr Slc [H-2b]----lethally irradiated C3H/He Slc [H-2k]) by pretreatment of the donors. The results suggest that the effectors responsible for the GVH reaction were abrogated by pretreatment of the donors with allogeneic recipient spleen cells plus CP in the H-2-matched combination, but donor pretreatment failed to abrogate GVH reaction in the H-2-mismatched combination.