Therapeutic Effect of SPK1 Gene Transfected Adipose Derived Mesenchymal Stem Cells on Experimental Autoimmune Encephalomyelitis Mice and Its Effect on T Helper Cell 17/Regulatory T Cells Balance / 中国医学科学院学报

Objective To investigate the therapeutic effect of SPK1 gene transfected adipose derived mesenchymal stem cells(ADMSC)on experimental autoimmune encephalomyelitis mice and the effect on T helper cell 17(Th17)/regulatory T(Treg) cells balance. Methods EAE was induced by myelin oligodendrocyte glycoprotein 35-55 in mice.Totally 44 mice were randomly divided into four groups:normal control group(NC group),model group(EAE group),ADMSC group,and ADMSC-SPK1 group.Forty days after injection,the pathological changes of brain and spinal cord,Th17/Treg-related inflammatory markers in brain tissue,expressions of interleukin-17A(IL-17A)and forkhead box protein p3(Foxp3)in brain and spinal cord tissue,and flow cytometric results of spleen immune cells were detected. Results Forty days after the injection,serious inflammatory cell infiltration and demyelination occurred in the brain and spinal cord of EAE group,whereas demyelination and axonal injury were improved in ADMSC group and ADMSC-SPK1 group.Compared with EAE group,the ADMSC group and ADMSC-SPK1 group had significantly improved levels of IL-17A(

CD4+CD69+ T cells and CD4+CD25+FoxP3+ Treg cells imbalance in peripheral blood, spleen and peritoneal lavage from pristane-induced systemic lupus erythematosus (SLE) mice

Abstract Background: Adaptive immune cells, including CD4+CD69+ and CD4+CD25+FoxP3+ regulatory T (Treg) cells, are important for maintaining immunological tolerance. In human systemic lupus erythematosus (SLE), CD4+CD25+FoxP3+ Treg cells are reduced, whereas CD69 expression is increased, resulting in a homeostatic immune imbalance that may intensify autoreactive T cell activity. To analyze the mechanisms implicated in autotolerance failure, we evaluated CD4+CD69+ and CD4+CD25+FoxP3+ T cells and interleukin profiles in a pristane-induced SLE experimental model. Methods: For lupus induction, 26 female Balb/c mice received a single intraperitoneal 0.5 ml dose of pristane, and 16 mice received the same dose of saline. Blood and spleen samples were collected from euthanized mice 90 and 120 days after pristane or saline inoculation. Mononuclear cells from peripheral blood (PBMC), peritoneal lavage (PL) and splenocytes were obtained by erythrocyte lysis and cryopreserved for further evaluation by flow cytometry using the GuavaEasyCyte TM HT. After thawing, cells were washed and stained with monoclonal antibodies against CD3, CD4, CD8, CD25, CD28, CD69, FoxP3, CD14 and Ly6C (BD Pharmingen TM). Interleukins were quantified using Multiplex® MAP. The Mann-Whitney test and the Pearson coefficient were used for statistical analysis, and p < 0.05 considered significant. Results: Compared with the controls, SLE-induced animals presented increased numbers of CD4+CD69+ T cells in the blood on T90 and T120 (p = 0.022 and p = 0.008) and in the spleen on T120 (p = 0.049), but there were decreased numbers in the PL (p = 0.049) on T120. The percentage of Treg was lower in blood (p < 0.005 and p < 0.012) on T90 and T120, in spleen (p = 0.043) on T120 and in PL (p = 0.001) on T90. Increased numbers of CD4+ CD69+ T cells in the PL were positively associated with high IL-2 (p = 0.486) and IFN-γ (p = 0.017) levels, whereas reduced Treg cells in the blood were negatively correlated with TNFα levels (p = 0.043) and positively correlated with TGFβ1 (p = 0.038). Conclusion: Increased numbers of CD4+CD69+ T cells and reduced numbers of CD4+CD25+FoxP3+ Treg cells with an altered interleukin profile suggests loss of autotolerance in pristane-induced lupus mice, which is similar to human lupus. Therefore, this model is useful in evaluating mechanisms of cellular activation, peripheral tolerance and homeostatic immune imbalance involved in human SLE.

Altered Tregs and oxidative stress in pregnancy associated lupus

Abstract Aim SLE is a systemic autoimmune disease generally affecting woman in the reproductive age. It is associated with an altered level of Tregs and oxidative stress while an increase in Tregs, and different antioxidant mechanisms to combat oxidative stress are essential for successful pregnancy. Hence, this study aims to determine the level of CD4+ and CD8+ Tregs and oxidative stress in pregnant lupus patients. Methods Ten healthy and 10 pregnant lupus volunteers from the North Indian population, within the age group of 20-30 years were enrolled in the study. All the patients were non-smokers, non-alcoholics and were not associated or undergoing therapy for any other disease. They had a SLEDAI of 37.4 ± 7.32 with 5.2 ± 1.93 years of disease duration. Oxidative stress was determined by measuring the enzyme activity of anti-oxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) and the level of reduced glutathione and lipids peroxidised, spectrophotometrically. Flowcytometry was performed for immunophenotyping to determine CD8+ and CD4+ Tregs. Results Elevated CD8+ Tregs and diminished CD4+ Tregs were observed in pregnant lupus patients. Oxidative stress was significantly increased as the activities of anti-oxidant enzymes and level of reduced glutathione was considerably diminished. There was a substantial increase in the amount of lipids peroxidised. Conclusion Pregnant lupus patients undergo considerable level of oxidative stress in comparison to healthy pregnant woman. The decreased level of CD4+ Tregs and an increase in CD8+ Tregs might be another important factor responsible for pregnancy associated complications. Hence, lupus leads to alterations in the necessary conditions for a successful pregnancy, which might eventually cause higher mortality, morbidity and associated complications.

Relationships of interleukin-10 with the regulatory T cell ratio and prognosis of cervical cancer patients

OBJECTIVE: This study investigated serum interleukin-10 (IL-10) levels, changes in peripheral blood CD4+CD25+ regulatory T cell (PBCDT) ratios, and the prognosis of cervical cancer (CC) patients. METHODS: Seventy patients with CC composed the observation group, and 70 healthy subjects composed the control group. The PBCDT ratios in the CC patients and healthy subjects were calculated. Serum IL-10 levels were detected with a double antibody sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS: The PBCDT ratio was higher in the patients with active CC [12.16±2.41%] than in the control subjects [6.34±1.05%]. Serum IL-10 levels were higher in the patients with CC [384±106 pg/ml] than in the control subjects [104±50 pg/ml]; the differences in both PBCDT ratio and IL-10 level were statistically significant (p<0.01). Serum IL-10 levels were positively correlated with PBCDT ratios (r=0.375, p<0.05). The 5-year patient survival rate was significantly higher in the low serum IL-10 group (64.2%) than in the high serum IL-10 group (42.8%, p=0.012). CONCLUSIONS: PBCDT ratios and serum IL-10 levels are related to CC activity. These factors are reciprocally related and influence one another, and both are involved in the development and progression of CC. Low IL-10 expression is beneficial regarding the survival of patients with CC.

T lymphocytes and macrophages in the intestinal tissues of dogs infected with Leishmania infantum / Linfócitos T e macrófagos nos tecidos intestinais de cães infectados com Leishmania infantum

Abstract This study was about a semi-quantitative analysis of T lymphocytes (CD4+ and CD8+, FoxP3+ regulatory T cells), and macrophages in the gut wall of dogs naturally infected with Leishmania infantum. Thirteen dogs were divided into three groups: group 1 (G1, n=5), dogs with canine visceral leishmaniasis (CVL) and infected with L. infantum amastigotes in the intestine; group 2 (G2, n=5), dogs with CVL but without intestinal amastigotes; and group 3 (G3, n=3), uninfected dogs (control group). There was no significant difference (p ≥ 0.05) on CD4+ and Treg cell numbers among the groups, whereas the levels of CD8+ T cells and macrophages were significantly higher in dogs from G1 group than in G2 and G3 (p ≤ 0.05), especially in intestinal segments with high parasite burden. Parasite burden correlated positively with levels of CD8+ T cells and macrophages (p ≤ 0.05), but was inversely correlated to levels of CD4+ T lymphocytes and FoxP3+ Treg cells. In conclusion, in the intestine of dogs with CVL, the increase of CD8+ T cells and macrophages population associated with high parasite burdens, but no changes of CD4+ T cells and FoxP3+ Treg cells suggest a possible immunoregulation by the parasite not dependent on Treg cells.

Resumo Este estudo foi uma análise semi-quantitativa de linfócitos T (CD4+, CD8+ e regulatórios - Treg FoxP3+) e macrófagos na parede intestinal de cães naturalmente infectados com Leishmania infantum. Treze cães foram divididos em três grupos: grupo 1 (G1, n=5) continha cães com leishmaniose visceral canina (LVC) e com amastigotas intestinais; grupo 2 (G2, n=5) continha cães com LVC, mas sem amastigotas intestinais e o grupo 3 (G3, n=3) continha cães não infectados (grupo controle). Verificou-se que não houve diferença significativa (p ≤ 0.05) no número de células CD4+ e de Treg entre os grupos, mas o número de células T CD8+ e macrófagos foi significativamente superior nos cães do grupo G1 em relação ao G2 e ao G3 (p ≤ 0,05), especialmente nos segmentos intestinais com altas cargas parasitárias. As altas cargas parasitarias correlacionaram positivamente com os números de CD8+ e macrófagos (p ≤ 0,05), mas negativamente com as células CD4+ e Treg. Em conclusão, no intestino dos cães com LVC, o aumento das populações de células T CD8+ e de macrófagos associado a altas cargas parasitárias, mas nenhuma alteração de células T CD4+ e células Treg FoxP3+ sugerem uma possível imunorregulação pelo parasita não dependente de células Treg.

Abnormal phenotypic distribution of regulatory and effector T cells in octogenarian and nonagenarian women / Distribuição fenotípica anormal das células T reguladoras e efetoras em mulheres octogenárias e nonagenárias

SummaryIntroduction:aging is associated with several immunologic changes. Regulatory (Treg) and effector T cells are involved in the pathogenesis of infectious, neoplastic, and autoimmune diseases. Little is known about the effects of aging on the frequency and function of these T cell subpopulations.Methods:peripheral blood mononuclear cells (PBMC) were obtained from 26 young (under 44 years old) and 18 elderly (above 80 years old) healthy women. T cell subpopulations were analyzed by flow cytometry.Results:elderly individuals had lower frequency of several activated effector T cell phenotypes as compared with young individuals: CD3+CD4+CD25+ (3.82±1.93 versus 9.53±4.49; p<0.0001); CD3+CD4+CD25+CD127+(2.39±1.19 versus 7.26±3.84; p<0.0001); CD3+CD4+CD25+ (0.41±0.22 versus 1.86±0.85, p<0.0001); and CD3+CD4+CD25highCD127+(0.06±0.038 versus 0.94±0.64, p<0.0001). Treg (CD3+CD4+CD25+CD127øFoxp3+) presented lower frequency in elderly individuals as compared to young adults (0.34±0.18 versus 0.76±0.48; p=0.0004) and its frequency was inversely correlated with age in the whole group (r=-0.439; p=0.013). The elderly group showed higher frequency of two undefined CD25øFoxp3+ phenotypes: CD3+CD4+CD25øFoxp3+(15.05±7.34 versus 1.65±1.71; p<0.0001) and CD3+CD4+CD25øCD127øFoxp3+(13.0±5.52 versus 3.51±2.87; p<0.0001).Conclusions:the altered proportion of different T cell subsets herein documented in healthy elderly women may be relevant to the understanding of the immunologic behavior and disease susceptibility patterns observed in geriatric patients.

ResumoIntrodução:o envelhecimento está associado a diversas alterações imunológicas. Células T reguladoras e efetoras estão envolvidas na patogênese de enfermidades infecciosas, neoplásicas e autoimunes. Pouco se sabe acerca dos efeitos da idade sobre a frequência e a função dessas populações celulares.Métodos:células mononucleares do sangue periférico foram obtidas de participantes saudáveis (26 com idade inferior a 44 anos e 18 acima de 80 anos). As subpopulações celulares foram analisadas por citometria de fluxo.Resultados:o grupo constituído por idosas apresentou menor frequência de vários fenótipos de células T efetoras ativadas em comparação com jovens: CD3+CD4+CD25+ (3,82±1,93 versus 9,53±4,49, p<0,0001); CD3+CD4+ CD25+CD127+ (2,39±1,19 versus7,26±3,84, p<0,0001); CD3+CD4+CD25high(0,41±0,22 versus 1,86±0,85, p<0,0001); CD3+CD4+CD25highCD127+(0,06±0,038 versus 0,94±0,64, p<0,0001). As células T reguladoras CD3+CD4+CD25highCD127øFoxP3+ apresentaram menor frequência em indivíduos idosos em comparação com adultos jovens (0,34±0,18 versus0,76±0,48, p=0,0004) e sua frequência foi inversamente correlacionada com a idade em todo o grupo (r=-0,439; p=0,013). O grupo de idosas apresentou maior frequência de dois fenótipos indefinidos (CD25øFoxP3+), células CD3+CD4+CD25øFoxP3+ (15,05±7,34 versus 1,65±1,71, p<0,0001) e células CD3+CD4+CD25øCD127øFoxP3+(13,0±5,52 versus 3,51±2,87, p<0,0001).Conclusão:as proporções alteradas de diferentes subpopulações de células T em idosas saudáveis contribuem para a compreensão dos padrões de comportamento e suscetibilidade a doenças imunológicas evidenciadas em pacientes geriátricos.

Eupatilin Ameliorates Collagen Induced Arthritis

Eupatilin is the main active component of DA-9601, an extract from Artemisia. Recently, eupatilin was reported to have anti-inflammatory properties. We investigated the anti-arthritic effect of eupatilin in a murine arthritis model and human rheumatoid synoviocytes. DA-9601 was injected into collagen-induced arthritis (CIA) mice. Arthritis score was regularly evaluated. Mouse monocytes were differentiated into osteoclasts when eupatilin was added simultaneously. Osteoclasts were stained with tartrate-resistant acid phosphatase and then manually counted. Rheumatoid synoviocytes were stimulated with TNF-alpha and then treated with eupatilin, and the levels of IL-6 and IL-1beta mRNA expression in synoviocytes were measured by RT-PCR. Intraperitoneal injection of DA-9601 reduced arthritis scores in CIA mice. TNF-alpha treatment of synoviocytes increased the expression of IL-6 and IL-1beta mRNAs, which was inhibited by eupatilin. Eupatilin decreased the number of osteoclasts in a concentration dependent manner. These findings, showing that eupatilin and DA-9601 inhibited the expression of inflammatory cytokines and the differentiation of osteoclasts, suggest that eupatilin and DA-9601 is a candidate anti-inflammatory agent.

Role of Regulatory T Cells in Transferable Immunological Tolerance to Bone Marrow Donor in Murine Mixed Chimerism Model

Constructing a bone marrow chimera prior to graft transplantation can induce donor-specific immune tolerance. Mixed chimerism containing hematopoietic cells of both recipient- and donor-origin has advantages attributed from low dose of total body irradiation. In this study, we explored the mechanism of mixed chimerism supplemented with depletion of Natural Killer cells. Mixed chimerism with C57BL/6 bone marrow cells was induced in recipient BALB/c mice which were given 450 cGy of gamma-ray irradiation (n = 16). As revealed by reduced proliferation and cytokine production in mixed leukocyte reaction and ELISpot assay (24.6 vs 265.5), the allo-immune response to bone marrow donor was reduced. Furthermore, the induction of transferable immunological tolerance was confirmed by adoptive transfer and subsequent acceptance of C57BL/6 skin graft (n = 4). CD4+FoxP3+ regulatory T cells were increased in the recipient compartment of the mixed chimera (19.2% --> 33.8%). This suggests that regulatory T cells may be therapeutically used for the induction of graft-specific tolerance by mixed chimerism.

Regulatory T cells: A review.

Regulatory T cells (Tregs) play a pivotal role in the homeostasis of the immune system and in the modulation of the immune response. Tregs have emerged as key players in the development and maintenance of peripheral immune tolerance. Broadly speaking, CD4+ T cells possessing the ability to suppress immune responses can be divided into two types: naturally occurring (nTreg) and inducible (iTreg) or adaptive regulatory cells. Naturally occurring thymus-derived CD4+CD25+ Tregs are a subset of T cells which have immunosuppressive properties and are 5%–10% of the total peripheral CD4+ T cells. In normal conditions, Tregs regulate ongoing immune responses and prevent autoimmunity. Imbalanced function or number of these cells, either enhanced or decreased, might lead to tumour development and autoimmunity, respectively. These cells thus play a major role in autoimmune diseases, transplantation tolerance, infectious diseases, allergic disease and tumour immunity. These natural properties make Tregs attractive tools for novel immunotherapeutic approaches. The in vivo manipulation or depletion of Tregs may help devise effective immunotherapy for patients with cancer, autoimmunity, graftversus- host disease, infectious diseases and allergic diseases. It is crucial to understand the biology of Tregs before attempting therapies, including (i) the injection of expanded Tregs to cure autoimmune disease or prevent graft-versus-host disease or (ii) the depletion or inhibition of Tregs in cancer therapy. Recent findings in murine models and studies in humans have opened new avenues to study the biology of Tregs and their therapeutic potential. This overview provides a framework for integrating these concepts of basic and translational research.

Depletion of CD25+ cells during acute toxoplasmosis does not significantly increase mortality in Swiss OF1 mice

The interleukin (IL)-2R alpha chain (CD25) is expressed on regulatory T cells (Treg), which constitute more than 85 percent of the CD25+ T cell population in a naïve mouse. CD25 is also expressed on effector T cells in mice suffering from an acute infection by the obligate intracellular protozoan parasite, Toxoplasma gondii. Lethal toxoplasmosis is accompanied by a significant loss of Treg in mice naturally susceptible to toxoplasmosis. The present study was done to explore the role of Treg cells using an anti-CD25 antibody-mediated depletion in mice naturally resistant to toxoplasmosis. Although a significant decrease in the percentage of Treg cells was observed following anti-CD25 monoclonal antibody injections, the depletion of CD25+ cells during acute toxoplasmosis did not significantly increase the mortality of Swiss OF1 mice and no significant difference was observed in the brain parasitic load between the mice in the depleted-infected and isotype-infected groups. We found no significant difference between the titres of total IgG in the sera of the mice from the two groups in the chronic phase. However, CD25+ cells depletion was followed by significantly higher levels of IL-12 in the serum of depleted mice than in that of mice injected with the isotype control antibody.

Subpopulations of Regulatory T Cells in Rheumatoid Arthritis, Systemic Lupus Erythematosus, and Behcet's Disease

Recently, subpopulations of regulatory T (Treg) cells, resting Treg (rTreg) and activated Treg (aTreg), have been discovered. The authors investigated the relationship between the change of Treg, aTreg and rTreg and autoimmune diseases. Treg cells and those subpopulations were analyzed by using the human regulatory T cell staining kit and CD45RA surface marker for 42 rheumatoid arthritis (RA), 13 systemic lupus sclerosis (SLE), 7 Behcet's disease (BD), and 22 healthy controls. The proportion of Treg cells was significantly lower in RA (3.8% +/- 1.0%) (P < 0.001) and BD (3.3% +/- 0.5%) (P < 0.01) compared to healthy controls (5.0% +/- 1.3%). The proportion of aTreg cells was also significantly lower in RA (0.4% +/- 0.2%) (P = 0.008) and BD (0.3% +/- 0.1%) (P = 0.013) compared to healthy controls (0.6% +/- 0.3%). The rTreg cells showed no significant differences. The ratio of aTreg to rTreg was lower in RA patients (0.4% +/- 0.2%) than that in healthy controls (0.7% +/- 0.4%) (P = 0.002). This study suggests that the decrement of aTreg not rTreg cells contributes the decrement of total Treg cells in peripheral blood of RA and BD autoimmune diseases. Detailed analysis of Treg subpopulations would be more informative than total Treg cells in investigating mechanism of autoimmune disease.

Análise do envolvimento de células T reguladoras na hanseníase / Analysis of the involvement of regulatory T cells in leprosy

A hanseníase é uma doença crônica causada por Mycobacterium leprae e apresenta diversas formas clínicas. O entendimento da interação parasita-hospedeiro na hanseníase evidenciou que ocorre a persistência assintomática do patógeno, caracterizando um estado de latência. Os fatores mais importantes relacionados com a permanência do patógeno são: a patogenicidade do agente infeccioso e o perfil da resposta imune, no qual os eventos de migração celular, produção de citocinas, as células efetoras e reguladoras são extremamente relevantes. As células T reguladoras (Treg) desempenham papel central na regulação da resposta imune em infecções crônicas o que favorece a persistência do patógeno. A importância de células T reguladores na hanseníase ainda é pouco conhecida. Neste trabalho investigou-se a presença de células T reguladoras em lesões e sangue periférico de indivíduos com hanseníase. Inicialmente avaliou-se a proliferação e a produção de citocinas por células mononucleares do sangue periférico (PBMC) de pacientes com hanseníase. Os resultados evidenciaram que não há diferenças quanto à proliferação de células T e produção de IFN-γ e TNF-α por células desses pacientes, mas a produção de IL-4 e IL-5 foi detectada apenas entre os pacientes com hanseníase virchoviana. Em relação à presença de células T reguladoras, os resultados evidenciaram aumento no número de linfócitos T CD4+CD25+FoxP3+ no sangue periférico de pacientes com hanseníase virchoviana. As células T reguladoras dos pacientes com hanseníase apresentaram elevada expressão de moléculas co-inibitórias PD-1, CTLA-4, GITR e ICOS. De modo relevante, as células T CD4+CD25+ isolados de pacientes com hanseníase virchoviana apresentaram maior atividade supressora quando comparado às células isoladas de pacientes com hanseníase tuberculóide. As células T CD4+CD25+ de pacientes com hanseníase virchoviana inibiram a proliferação de PBMC alogênico e a produção de IFN-γ e TNF-α...

Leprosy is caused by Mycobacterium leprae and its clinical features depend on the host immune background. The understanding of parasite-host interactions in leprosy have highlighted asymptomatic persistence of the pathogen, which indicates that this infection becomes latent. The most important factors related to the permanence of pathogens are: the pathogenicity of the infectious agents; the profile of the immune response developed by the host whose events of cellular migration, cytokines production, and the effector and regulatory cells are extremely relevant. The regulatory T cells (Treg) seem to play a central role in the regulation of the immune response in chronic infections, which favors the persistence of the pathogen. Herein, we analyzed the relation between tuberculoid and lepromatous leprosy with the presence and function of T regulatory cells from peripheral blood mononuclear cells (PBMC) and skin lesions from these patients. First, the proliferation and cytokine production of PBMC isolated from leprosy patients were analyzed. We did not observe any difference in the proliferation ability or IFN-γ and TNF-α release; however, the production of IL-4 and IL-5 was detected only in patients with lepromatous leprosy. Furthermore, T CD4+CD25+FoxP3+ cells were detected in the PBMC of patients with leprosy and these cells from lepromatous patients showed high expression of co-inhibitory molecules such as PD-1, GITR, CTLA-4 and ICOS. T CD4+CD25+cells isolated from patients with lepromatous leprosy were significantly more suppressive than the cells obtained from tuberculoid patients. In addition, TCD4+CD25+ cells isolated from patients with lepromatous leprosy inhibited allogeneic PBMC proliferation and their production of IFN-γ and TNF-α. The results also demonstrated that IL- 10 and TGF-ß were co-expressed with CD25+ cells at the inflammatory infiltrate of skin lesions from lepromatous patients, but similar results were not detected among tuberculoid...

Cancer biomarkers - Current perspectives.

In the recent years, knowledge about cancer biomarkers has increased tremendously providing great opportunities for improving the management of cancer patients by enhancing the efficiency of detection and efficacy of treatment. Recent technological advancement has enabled the examination of many potential biomarkers and renewed interest in developing new biomarkers. Biomarkers of cancer could include a broad range of biochemical entities, such as nucleic acids, proteins, sugars, lipids, and small metabolites, cytogenetic and cytokinetic parameters as well as whole tumour cells found in the body fluid. A comprehensive understanding of the relevance of each biomarker will be very important not only for diagnosing the disease reliably, but also help in the choice of multiple therapeutic alternatives currently available that is likely to benefit the patients. This review provides a brief account on various biomarkers for diagnosis, prognosis and therapeutic purposes, which include markers already in clinical practice as well as various upcoming biomarkers.

Two-signal blockade with anti-CD45RB and anti-CD154 monoclonal antibodies inhibits graft rejection via CD4-dependent mechanisms in allogeneic skin transplantation

Blockade of signal 1 or 2 for T-cell activation by the use of anti-CD45RB and anti-CD154 monoclonal antibodies (mAb) (two-signal blockade) has been proven effective in preventing or delaying graft rejection. However, the mechanisms of its immunomodulatory effects are clearly unknown and the present studies were performed to determine how the two-signal blockade modulate allogeneic immune responses, especially T-cell mediated cellular immunity, in a murine skin allograft model. We now report on the profound inhibition of alloreactive T cells by two-signal blockade via CD4-dependent mechanisms. C57BL/6 mice of BALB/c skin allograft were treated with anti-CD45RB, anti-CD154, CTLA4-Ig, or their combinations. For depletion of CD4 or CD8 T cells, the recipients received CD4-depleting or CD8-depleting mAb. We confirmed that survival of skin allograft was markedly prolongated in the two-signal blockade-treated group. In depletion study, anti-CD45RB, anti-CD154 and CD4-depleting mAb-treated group showed acute rejection of skin allograft in contrast to CD8-depleting group treated with the two-signal blockade. In the group treated with the two-signal blockade, the proportions of CD4+CD45RB(low)and CD8+CTLA-4 regulatory T cells were increased while effector CD8+ T cells, including IFN-gamma-secreting and CD8+CD62L(low)T cells, were decreased when compared with non-treated group. In contrast, the CD4-depleted group treated with the two-signal blockade resulted in recovery from immunoregulatory effects of two-signal blockade. In addition, results of IL-4 and IL-10 production were also showed CD4-dependence. Therefore, the two-signal blockade is accompanied by CD4-dependent mechanisms in allogeneic skin transplantation.

Separation of human suppressor and helper T cells by concanavalin A-coated sheep erythrocytes.

Normal human peripheral blood mononuclear leukocytes (PBML) were activated by concanavalin A (Con A). Con A-activated and non-activated T cells were separated by E (AET) rosettes (2-aminoethylisothiouronium hydrobromide treated sheep erythrocyte rosettes). Purified T cells were rosetted with Con A-coated sheep red blood cells (Con A-SRBC) at 37 degrees C resulting in Con A-SRBC rosetted and non-rosetted T cells. The Con A-SRBC rosetted T lymphocytes in the T lymphocytes from Con A-activated and non-activated PBML were 44.4 +/- 5.4 percent and 16.0 +/- 7.5 percent (Mean +/- S.D.) while the Con A-SRBC non-rosetted T lymphocytes were 55.6 +/- 5.4 percent and 84.0 +/- 7.5 percent respectively. The Con A-SRBC rosetted and non-rosetted T cells were separated by Ficoll-Hypaque gradient centrifugation. Functional studies of Con A-SRBC rosetted and non-rosetted T cells were performed by in vitro tests using pre-amplified reverse hemolytic plaque assay for measuring numbers of immunoglobulin G (IgG) secreting cells and ELISA quantitation of IgG concentration. Both techniques were used to assess the suppressor and helper functions of the Con A-SRBC rosetted and non-rosetted T cells. The Con A-SRBC rosetted cells obtained from T cells of Con A-activated PBML showed strong suppressor activities to normal PBML in both pre-amplified reverse hemolytic plaque assay and sandwidh ELISA of IgG concentration, while the Con A-SRBC non-rosetted T cells demonstrated strong helper activities to normal PBML in both assay systems.(ABSTRACT TRUNCATED AT 250 WORDS)

De Hahnemann a la inmunologia actual / From Hahnemann to the actual immunology

Los conocimientos actuales sobre inmunologia, han llegado a las mismas conclusiones que el Dr. Samuel Hahnemann en 1813 expreso sobre la dermatitis por contacto y el Rhus toxicodendron. Los inmunologos, al estudiar los efectos de diferentes haptenos capaces de producir dermatitis por contacto, entre los que esta el Rhus toxicodendron, pudieron constatar que la inmunidad celular es la directamente responsable de la patologia manifiestal; asimismo, han demonstrado que los haptenos administrados por via oral a pequenas dosis provocan la proliferacion de linfocitos T supresores que limitan y regulan la respuesta celular. Es importante hacer notar que el Dr. Hahnemann desarrollo dentro de su terapeutica el uso del Rhus toxicodendron y que este medicamento se emplea en terapia homeopatica actual para curar padecimientos en los que la inmunidad celular es la responsable de las lesiones tisulares como son algunos cuadros de dermatitis por contacto, tuberculosis, enfermedades virales y artritis reumatoide. Los inmunologos han concluido conceptos que los llevan a la terapia homeopatica en lo que se refiere a la dermatitis por contacto; quedando por comprobar experimentalmente si en los otros padecimientos en donde se usa el Rhus toxicodendron tambien intervienen los linfocitos T supresores para impedir el dano a los tejidos

Blood helper/suppressor lymphocyte ratio in sarcoidosis.

The blood helper/suppressor ratio was measured in 38 patients with biopsy-proved sarcoidosis. There was no relationship between this peripheral helper/suppressor ratio and the activity of the granulomatous process. This test needs further evaluation before its routine use in assessing activity in sarcoidosis.