DNA-synthesizing T and non-T cells in chronic lymphocytic leukemia.

In 21 patients with chronic lymphocytic leukemia (CLL) and in 8 hematologically normal persons the number of DNA-synthesizing peripheral blood lymphocytes was investigated by autoradiographic techniques. The lymphocytes were differentiated by EN-rosette tests into T and non-T lymphoid cells. The results show a normal number of proliferating T lymphoid cells and an increased number of proliferating non-T lymphoid cells in clinical stages O-I. Stages III-IV demonstrate a significant increase of the proliferation rate of both T and non-T lymphoid cells. The possible pathogenetic factors and the prognostic value of these results are discussed.     

The multiple mixed lymphocyte reaction: variables important in the test as a measure of lymphocyte competence in man.

In order to utilize the mixed lymphocyte reaction (MLR) as an assay of T-lymphocyte competence, pools of target lymphocytes obtained from different individuals are used to increase the magnitude and decrease the variation of the in vitro response. We evaluated variations in MLR response due to variations in target cell populations. Response increased with an increased target/responder cell ratio. Peak response occurred with a target/responder cell ratio of between 1:1 and 1:4. Response to a pool of lymphocytes from different individuals increased as the number of individuals contributing to the pool increased. Peak stimulation occurred with three to four different donors to the target cell pool. Stimulation produced by pooled target cells resulted in a higher mean index of stimulation and decreased variation of response as compared to stimulation produced by target cells from individual donors. Stimulation produced by pooled target cells was approximately equal to the sum of the stimulation produced by each of the target cell populations acting alone. These findings indicate a practical method of modifying the MLR as a test of T-lymphocyte function.     

不同临床类型乙型病毒感染者外周血T 细胞亚群与血清HBV DNA 载量 及HBeAg 滴度相关性分析

目的:探讨慢性乙型肝炎病毒(HBV)感染患者外周血T细胞亚群与血清HBV DNA载量及HbeAg滴度的关系。方法:选取103名HBV感染患者和20名健康者为研究对象。流式细胞术检测外周血T细胞亚群,聚合酶链式反应及酶免疫分析法分别检测血清HBV DNA载量及HbeAg滴度。结果:慢性乙型肝炎患者和慢性HBV携带者外周血CD3+T、CD4+T淋巴细胞亚群百分数低于健康对照组,结果有统计学意义(P<0.05或0.01;而CD8+T细胞亚群则呈现相反趋势,结果亦有统计学意义(P<0.05或0.01)。HBeAg阴性组中,HBVDNA水平与CD8+T细胞亚群百分数呈正相关(r=0.567,P<0.01),与CD4+/CD8+T细胞亚群百分数比值呈负相关(r=-0.601,P<0.01),而与CD3+T、CD4+T细胞亚群百分数无相关性。HBeAg阳性组中,HBV DNA水平及HbeAg滴度与CD3+T、CD4+T、CD8+T细胞百分数及CD4+/CD8+T细胞百分数均无相关性(P>0.05)。结论:不同临床类型的慢性乙型肝炎病毒感染患者外周血T细胞亚群存在不同程度细胞免疫功能降低和细胞免疫调节异常。HbeAg阴性的HBV感染患者,其血清HBV DNA水平与外周血T淋巴细胞免疫存在相关性。     

Flow cytometric analysis of T-lymphocyte subpopulations in B-cell chronic lymphocytic leukemia: correlation with clinical stage

Several authors have studied the T-lymphocyte subpopulations in B-cell chronic lymphocytic leukemia (B-CLL), but previous studies were performed after preceding enrichment procedures, which are known to cause selective losses of certain subpopulations. To correct for this deficiency we used flow cytometric analysis, which enabled us to measure subpopulations directly on total blood samples. We studied T-lymphocyte subsets with OKT monoclonal antibodies in 45 patients with B-CLL. Serum levels of IgG, IgA and IgM were assayed simultaneously and findings were correlated with clinical stage (Rai classification). The absolute number of CD4-positive cells decreased in more advanced Rai stages, while the absolute number of CD8-positive cells increased, resulting in a progressive reduction in CD4/8 ratio. Results from patients in stages with equal prognosis (Rai I and II, Rai III and IV) were similar and when these results were grouped the observed differences were highly significant and clearly correlated with all prognostic groups.     

不同临床类型乙型病毒感染者外周血T细胞亚群与血清HBVDNA载量及HBeAg滴度相关性分析

目的：探讨慢性乙型肝炎病毒（HBV）感染患者外周血T细胞亚群与血清HBVDNA载量及HbeAg滴度的关系。方法：选取103名HBV感染患者和20名健康者为研究对象。流式细胞术检测外周血T细胞亚群,聚合酶链式反应及酶免疫分析法分别检测血清HBVDNA载量及HbeAg滴度。结果：慢性乙型肝炎患者和慢性HBV携带者外周血CD3可、CD4T淋巴细胞亚群百分数低于健康对照组,结果有统计学意义（P〈0．05或0．01;而CD8＋T细胞亚群则呈现相反趋势,结果亦有统计学意义（P〈0．05或0．01）。HBeAg阴性组中,HBVDNA水平与CD8T细胞亚群百分数呈正相关（r=0．567,P〈0．01）,与CD47CD8＋T细胞亚群百分数比值呈负相关（r=-0．601,P〈0．01）,而与CD3＋T、CD4＋T细胞亚群百分数无相关性。HBeAg阳性组中,HBVDNA水平及HbeAg滴度与cD3＋1r、cD41、CD8叮细胞百分数及CD47CD8＋T细胞百分数均无相关性（P〉0．05）。结论：不同临床类型的慢性乙型肝炎病毒感染患者外周血T细胞亚群存在不同程度细胞免疫功能降低和细胞免疫调节异常。HbeAg阴性的HBV感染患者,其血清HBVDNA水平与外周血T淋巴细胞免疫存在相关性。     

Trypanosoma musculi: characterization of the T-lymphocyte dependency of immunity by selective immunomodulation of the mouse, Mus musculus

Trypanosoma musculi is a hemoflagellate parasite producing a characteristic course of infection in the mouse, terminating in elimination of the parasite from the vascular system with permanent immunity to reinfection. While this elimination is known to require functional T lymphocytes, the role of these cells has remained undefined. The current study examined the role of T-lymphocyte dependency by the selective in vivo depletion of T-lymphocyte subsets by monoclonal antibodies or immunosuppressive pharmacologic agents. In the former approach, monoclonal antibodies specific for the murine T-lymphocyte surface antigens Thy 1.2, Lyt 2, or L3T4 were administered to mice, resulting in functional depletion of either all T lymphocytes or the T-helper or T-cytotoxic subsets. Subsequent infection with T. musculi revealed that elimination of the T-helper, but not the T-cytotoxic, phenotype resulted in a prolonged and elevated parasitemia. This enhancement of parasitemia was similar to that produced with depletion of all T lymphocytes (i.e., Thy 1.2+ cells), suggesting that the T-helper cell was most important in parasite elimination. In the latter approach, pharmacologic agents displaying selective immunosuppressive activity were employed to inactivate, rather than destroy, T-lymphocyte subpopulations. In vivo inactivation of T-helper lymphocytes by the fungal metabolite cyclosporin-A enhanced the level of parasitemia in treated animals and resulted in a protracted duration of infection. In contrast, treatment with the highly substituted anthracenedione AEAD, which has been demonstrated to selectively inactivate T-cytotoxic cells, had no appreciable effect on the kinetics of infection. These results strongly suggest that the T-lymphocyte dependency of Trypanosoma musculi elimination is due predominantly to the action of the T-helper, rather than T-cytotoxic, lymphocyte.     

Delineation of the development of T lymphocytes from leukemic null lymphocytes upon induction by conditioned medium

Null lymphocytes, lacking B- and T-lymphocyte markers, were isolated from PBL of patients with acute lymphocytic leukemia. Upon culture in the presence of medium produced from PHA-stimulated allogeneic lymphocytes, induction of these cells to T lymphocytes occurred. Within 18 hr, they acquired the capacity to form SRBC rosettes and bind complement components, IgG or IgM. This differentiation, as supported by cell cycle kinetic analysis, was accompanied by lymphocyte activation, inferable from warm SRBC rosetting. Capping of these rosettes was identified as indicative of early T lymphocytes. During T-lymphocyte development subclasses bearing complement receptors, followed by IgG and finally IgM receptors appeared. The emergence of subclasses, functionally expressed by a gain in MLC responsiveness and stimulatory capacity reflected T-lymphocyte maturation. Simultaneous with the later decrease of the subclasses was a decrease in MLC reactivity. This elucidation of T-lymphocyte development may help in dissection of the lymphoid system.     

5-氮杂胞苷对T淋巴细胞Jurkat miR-126及IFN-γ、GATA3、ROR-γ、Foxp3表达的影响

目的:探究甲基化酶抑制剂5-氮杂胞苷(5-azacytidin,5-aza)对T淋巴细胞(Jurkat)mi R-126、Th1/Th2、Th17/Treg细胞亚群及因子IFN-γ、GATA3、ROR-γ和Foxp3的调控作用。方法:采用不同浓度5-aza干预T淋巴细胞,24 h、48 h后检测其对细胞增殖抑制作用;实时荧光定量PCR、Western Blot检测5-aza干预后mi R-126表达水平以及IFN-γ、GATA3、ROR-γ和Foxp3的m RNA及蛋白表达水平;流式细胞术检测5-aza干预后Th1/Th2、Th17/Treg细胞亚群分化比例。结果:甲基化酶抑制剂干预T淋巴细胞后,细胞抑制率随5-aza浓度增大及作用时间延长呈递增趋势(P<0.01);细胞抑制率在24 h、48 h,低、中、高浓度下分别为(14.73±0.93)%、(32.67±8.40)%、(60.87±5.78)%以及(18.98±0.73)%、(39.80±8.42)%、(64.11±6.04)%;抑制率在24 h与48 h之间无差异(P>0.05)。甲基化酶抑制剂干预后mi R-126表达降低(P<0.01);IFN-γ蛋白表达降低(P<0.05)、Th1细胞亚群数目降低(P<0.01);GATA3 m RNA和蛋白表达升高(P<0.05)、Th2细胞亚群数目增加(P<0.01);ROR-γ蛋白表达降低(P>0.05)、Th17细胞亚群数目降低(P<0.05);Foxp3 m RNA和蛋白表达升高(P>0.05)、Treg细胞亚群数目增加(P<0.05)。结论:甲基化酶抑制剂可以下调Jurkat细胞mi R-126基因表达;下调Th1、Th17细胞亚群分化,上调Th2、Treg细胞亚群分化;调控细胞因子IFN-γ、GATA3、ROR-γ和Foxp3的表达。     

The involvement of T lymphocytes in the pathogenesis of endometriotic tissues overgrowth in women with endometriosis

BACKGROUND: Endometriosis, uncontrolled proliferation of ectopic and eutopic endometriotic tissues, is common in women at reproductive age, and may affect fertility. The role of macrophages in the pathogenesis is well proved, but engagement of T cells in the pathogenesis of endometriosis is a matter of controversy. AIMS: T-cell involvement in the pathogenesis of endometriosis was the objective of our study performed on women aged 24-46 years with diagnosed endometriosis. All the patients that were studied underwent diagnostic laparoscopy. METHODS: We evaluated the distribution of T-lymphocyte subpopulations in peripheral blood (PB), peritoneal fluid (PF) and in endometriotic tissues (ET), as well as cytokines [interleukin (IL)-2, IL-4, IL-10, IL-12, interferon (IFN)-gamma] production by peripheral blood lymphocytes. IFN-gamma, tumor necrosis factor (TNF)-alpha, IL-4 and IL-6 were investigated for their intracellular presence. The experiments were carried out before and after 6 months treatment with the GnRH-Analogous Goserelin (Zeneca Pharmaceuticals). The number of performed investigations is presented. Statistical analysis was performed using Statistica/Win 5.0 software and Student''s t-test, the paired Student t-test and Fisher''s exact test when appropriate. RESULTS: We have compared the lymphocyte subset re-distribution with regard to the American Fertility Society (AFS) stages and scores, but no differences were observed. The significant increase in CD4:CD8 ratio, the decrease in the number of natural killer (NK) cells in PB and the decrease in CD4:CD8 ratio in PF and ET of women with endometriosis was noted. The diminished IFN-gamma secretion by phytohemagglutinim (PHA)-stimulated lymphocytes in vitro derived from women with endometriosis and increased IL-4 production may be responsible for defective immunosurveillance against overgrowth of endometriotic tissues. The diminished NK cells number in PB of women with endometriosis argues for such a hypothesis. The increased deposits of proinflammatory IL-6 and TNF-alpha in the T lymphocytes of women with endometriosis may be related to T-regulatory lymphocyte function and their inability to suppress cell proliferation in endometriosis. GnRH-Analogous Goserelin treatment normalises cytokine production and induces patient recovery. CONCLUSIONS: The significant functional and phenotypic differences between the lymphocytes from healthy women and women with endometriosis were noted. The diminished IFN-gamma production in relation to decreased NK cells number and the increased IL-4 production before the treatment and normalisation after the treatment suggest the involvement of the deregulated T-cell system in the growth stimulation and recruitment of endometriotic cells. The increased CD4:CD8 ratio, IL-6, TNF-alpha deposits and diminished anti-inflammatory IL-10 production by lymphocytes may participate in the pathogenesis of endometriosis, and may secondarily affect the monocyte/macrophage function.     

Participation of the cyclase system in the molecular mechanisms of differentiation control of immunocompetent cells

The effects of polypeptide thymic and bone marrow factors on the cyclase system of rat thymus and spleen lymphocytes were studied. It was shown that the induction of maturation of rat T-lymphocyte precursors into immunocompetent T-cells under effects of the thymic factor is accompanied by the activation of the adenylate cyclase system and the elevation of the cAMP/cGMP ratio. The observed increase in the cGMP level in splenic lymphocytes suggests the presence of cAMP- and cGMP-dependent steps of in the reaction of T-lymphocyte maturation. The bone marrow factor causes an elevation of the cAMP level only in splenic lymphocytes, which points to differences in the lymphocyte subpopulations that are sensitive to thymus and bone marrow factors. Impairments in T-lymphocyte maturation in patients with immunodeficiencies are concomitant with shifts in the isoenzyme spectrum of lactate dehydrogenase in peripheral blood lymphocytes as well as with changes in the sensitivity of the cAMP system to the thymic factor and isoproterenol. These disturbances are relieved by administration of the thymic factor. The roles of the cyclase system and polypeptide thymic and bone marrow factors in the molecular mechanisms of immunocompetent cell maturation are discussed.     

An attempt to use the natural binding of bacteria to lymphocytes in examining atopic patients

The termination of different subsets in apparently homogeneous cell population of T lymphocytes seems to be extremely important in the investigation of allergic diseases and can be of diagnostical use. It has been proved that the dysfunction of those subsets is very important pathogenetic mechanism of atopy. The existing technique using monoclonal antibodies to cell surface markers is rather expensive and has even some disadvantages. It has been published recently that some strains of bacteria were capable to bind spontaneously to human lymphocytes. Simultaneous use of more bacterial strains permitted to identify two B-cells and four T-cells subsets. The interaction of lectins on the lymphocyte surface and polysaccharide substances of the bacterial cell wall is supposed to be the mechanism of binding. In the present study an attempt was made to find out whether there is a difference in the binding of bacteria to lymphocytes between normal subjects and atopics and whether changes occur in this phenomenon after application of immunotherapy. It has been found that this qualitatively novel way of binding cannot be used for laboratory characterization of atopic subjects. No differences were observed in T-lymphocyte subsets identified by bacterial adherence between allergic and normal subjects. Immunotherapy failed to influence the binding. No correlation has been found with the method using monoclonal antibodies. Statistical evaluation revealed considerable dispersion of results obtained.     

Increased frequency of micronuclei in B and T8 lymphocytes from smokers

The frequency of micronuclei was measured in peripheral B lymphocytes and some T lymphocyte subpopulations from 5 medium-tar cigarette smokers, and 5 non-smokers with no regular exposure to tobacco smoke. The peripheral lymphocytes were stimulated in vitro with phytohemagglutinin and B lymphocytes and the various T lymphocyte subsets were classified by a recently developed MAC (Morphology, Antibody, Chromosomes) method which allows the immunologic identification of different cell lineages. An increased frequency of micronuclei was observed in B and especially in the suppressor/cytotoxic T8 lymphocytes from smokers, as compared with non-smoker values. In non-smoker cultures, no differences in the frequency of micronuclei were observed among the different T lymphocyte subsets. In these cultures, B cells tended to have a higher frequency of micronuclei than did T cells. The proportions of B cells and the various T subpopulations among mitotic and interphasic lymphocytes from smokers and non-smokers were also determined. The proportions of B cells and T cell subsets among all mitotic lymphocytes were similar in smokers and non-smokers. Contrarily, a significant decrease in the proportion of T8 lymphocytes among all interphasic lymphocytes was observed in cultures derived from smokers.     

Protein malnutrition up-regulates growth hormone receptor expression in rat splenic B lymphocytes

The reciprocal interaction between the endocrine and immune systems has been the subject of active research during the last decade, and an important body of evidence has accumulated supporting the role of the GH/IGF axis in immune function. More recently, the GH/IGF axis has been postulated as playing an important role in the modulation of stress conditions, such as catabolic stages, aging-related disorders, immunodeficient aids patients and malnutrition. Whether these effects are exerted through endocrine, autocrine or paracrine mechanisms remains to be determined for different immune cell types and tissues. The aim of the current study was to define which specific subsets of lymphocytes are the primary targets for GH action. In addition, the regulatory role of stress induced by protein restriction was investigated with respect to the relative distribution of GH receptor positive lymphoid cells. Normal growing rats were fed isocaloric diets with variable protein content (0, 4, 8, 12 and 20%) for a period of 14 days. The lymphoid cells were then separated from spleen, lymph nodes and peripheral blood lymphocytes. Flow cytometry analysis measured the binding characteristics of Fluos-rrGH to lymphocytes together with specific PE-labelled mAbs defining CD4+ and CD8+ T cells and B lymphocytes. The pattern of expression of the GH receptor differed among the lymphoid tissues and cell subsets. Spleen was the most responsive organ to protein deprivation with highest GH receptor expression in B lymphocytes, followed by CD4+ T cells. As the protein intake was decreased from 20% to 0%, the percentage of GHR positive cells increased from 12% to 52% in splenic B lymphocytes and from 8% to 17% in CD4+ T cells. In contrast, only 10%-13% of lymphocytes in lymph nodes and 2%-4% in circulation, showed binding sites to GH associated with protein deprivation. In conclusion, the increase in GH receptors on lymphocytes under catabolic stress induced by protein malnutrition gives support to the hypothesis of a modulatory role of the GH/IGF axis in preserving the homeostasis of immune tissues.     

Characterization of T-lymphocyte subpopulations infiltrating primary breast cancer

Summary Characterization of T-lymphocyte subpopulations adjacent to and infiltrating the primary tumor of breast cancer was carried out using a direct immunofluorescence procedure with the antibodies anti-(Leu-2a) for suppressor/cytotoxic (CD8⁺) and anti-(Leu-3a) for helper/inducer (CD4⁺) T-lymphocytes. Fifty-six primary malignant tumors with lymphoid infiltration were studied. The majority (58.9%) were infiltrating duct carcinoma. There were metastases to axillary lymph nodes in 6.67% of the patients. Massive lymphoid infiltration (>40 lymphocytes per ×400 microscopic field) was found in 19.6% of the tumors and moderate infiltration (20–40 lymphocytes per field) in 51.8%. In all the tumors studied there was a reversed CD4⁺/CD8⁺ ratio as compared to that found in normal peripheral blood. In 66.1% the CD4⁺/CD8⁺ ratio (helper/suppressor) was less than 1.0. The reversed ratio was due to a significant decrease in the number of helper cells (P<0.0005). The most significant drop was in the stroma area (P<0.0001) as well as in the tumor tissue (P=0.001). Of particular interest was the significant positive correlation between the age of the patients and an increased number of CD4⁺lymphocytes in the stroma (P=0.02). Significant negative correlations were found between a reduced number of CD4⁺ lymphocytes or CD4⁺/CD8⁺ ratio and several histological parameters: tumor diameter, pleomorphism, nucleus/cytoplasm ratio. There was also a significant positive correlation between the total number of CD8⁺ lymphocytes infiltrating the tumor tissue and the number of axillary lymph nodes with metastatic disease (P=0.03). It is suggested that the reversed ratio of CD4⁺/CD8⁺ lymphocytes may significantly affect the host/tumor immune surveillance.     

Characterization of thymus-derived lymphocyte subsets in acute Epstein-Barr virus-induced infectious mononucleosis.

Changes in thymus-derived (T) lymphocyte subpopulation numbers were studied in patients with acute and convalescent Epstein-Barr virus (EBV)-induced infectious mononucleosis (LM). T cell subsets were characterized by the presence of Fc receptors for IgG (TG), for IgM (TM) or by the absence of either receptor (Tnon-M, non-G). We found that in acute IM, total numbers of T and B lymphocytes were elevated (p less than 0.01). Of the T lymphocyte subsets, the total number of Tnon-M, non-G lymphocytes was increased six fold compared to normal subjects (p less than 0.001) and included the majority of the atypical T lymphocytes. The number of total TG and TM lymphocytes was moderately increased (p less than 0.05). In convalescent IM patients, the number of total T cells remained slightly elevated (p less than 0.02) whereas proportions and absolute numbers of B lymphocytes and T cell subsets returned to near normal levels. Thus, acute Epstein-Barr virus-induced IM is associated with a T lymphocytosis which is composed predominantly of atypical T cells which lack detectable Fc receptors for IgG or IgM.     

Characterization of porcine T lymphocytes and their immune response against viral antigens.

T lymphocytes play a central role in the antigen-specific immune response against various pathogens. To detect and to characterize porcine T lymphocytes, monoclonal antibodies (mAb) against leukocyte differentiation antigens had been raised and classified for their specificity. Analyses of porcine T lymphocytes with specific mAb against CD4 and CD8 differentiation antigens revealed differences in the composition of the porcine T-lymphocyte population compared to other species. In addition to the known subpopulations, CD4+CD8- T helper cells and CD4-CD8+ cytolytic T lymphocytes, extra-thymic CD4+CD8+ T lymphocytes and a substantial proportion of CD2-CD4-CD8- T cell receptor (TcR)-gamma delta+ T cells could be detected in swine. Functional analyses of porcine T-lymphocyte subpopulations revealed the existence of two T-helper cell fractions with the phenotype CD4+CD8- and CD4+CD8+. Both were reactive in primary immune responses in vitro, whereas only cells derived from the CD4+CD8+ T-helper-cell subpopulation were able to respond to recall antigen in a secondary immune response. With regard to T lymphocytes with cytolytic activities, two subsets within the CD4-CD8+ T-cell subpopulation could be defined by the expression of CD6 differentiation antigens: CD6- cells which showed spontaneous cytolytic activity and CD6+ MHC I-restricted cytolytic T lymphocytes including virus-specific cytolytic T lymphocytes. These results enable now a detailed view into the porcine T-cell population and the reactivity of specific T cells involved in the porcine immune response against pathogens. Furthermore this knowledge offers the possibility to investigate specific interactions of porcine T lymphocytes with virus-specific epitopes during vaccination and viral infections.     

Immune status of Greek patients with beta-thalassemia major negative for anti-HIV

Patients with thalassemia who receive multiple blood transfusions are at risk for the acquired immunodeficiency syndrome. Peripheral blood lymphocyte subpopulations were studied in 22 multitransfused thalassemic patients; 10 patients were without splenectomy and 12 were studied after splenectomy. Both groups were negative for anti-HIV. Four additional patients who were found positive for anti-HIV and ten healthy controls were also included in this study. Patients without splenectomy compared to controls and to patients after splenectomy showed a significant decrease of both percentage (p less than 0.001) and absolute numbers (p less than 0.001) of Leu-7+ cells without significant abnormalities of T4/T8 ratio (1.56 +/- 0.4). Patients after splenectomy compared to controls and to patients without splenectomy showed a significant increase of the absolute numbers of lymphocytes and lymphocytes subsets T11+, T3+, T4+, T8+ and SmIg+ cells. In the seropositive patients for HIV only a significant increase of the absolute number of T8+ cells was observed while the T4/T8 ratio was 1.24 +/- 0.73. The decrease in the percentage of Leu-7+ cells in patients without splenectomy correlated inversely to the total amount of blood transfused. In conclusion patients with thalassemia had normal T4/T8 ratio and did not show the abnormal immunologic profile that has been reported in haemophiliacs.     

Increased incidence of Ia antigen-bearing T lymphocytes in the spontaneously diabetic BB rat

The frequency of Ia-positive T lymphocytes in spontaneously diabetic BB rats was assessed by using monoclonal antibodies and a fluorescence-activated cell sorter. These cells peaked in frequency during the early stages of hyperglycemia, with a gradual decline toward normal as the disease progressed. Significantly increased numbers of Ia-positive T cells were detected in both helper (W3/25+) and cytotoxic-suppressor (OX8+) subsets. The elevated levels of Ia-positive T lymphocytes in these rats may be relevant to the immune destruction of their beta cells.     

Cytochemical profile of immunoregulatory T-lymphocyte subsets defined by monoclonal antibodies

Immunogold staining in combination with enzyme cytochemistry was used to determine the cytochemical profile of the immunoregulatory T-lymphocyte subpopulations defined by the monoclonal antibodies OKT3, OKT4, OKT8, and OKM1 in normal peripheral blood. Leukocyte suspensions were first incubated with the monoclonal mouse antibodies and then with colloidal gold-labeled goat antimouse antibodies. The cells were fixed and cytocentrifuge preparations were made. Cytochemical reactions for the detection of peroxidase, acid alpha-naphthyl acetate esterase, acid phosphatase, and beta-glucuronidase were performed on these preparations. Under light microscopy, lymphocytes reacting with the monoclonal antibodies had numerous dark granules around their surface membrane. In the cytoplasm the intracellular enzymatic activities were stained. The T-lymphocytes were characterized by a dot-like activity for the three enzymes. No significant difference could be found between the cytochemical profile of the T-helper (OKT4 positive) and T-cytotoxic suppressor cell populations (OKT8 positive). A few cells with lymphocyte morphology reacted with the OKM1 monoclonal antibody. Their cytochemical characteristics were different from those of mature T-cells (OKT3 population) or mature monocytes. From the comparison of their cytochemical characteristics, we can conclude that there is little correlation between the immunoregulatory T-lymphocyte subsets defined by these monoclonal antibodies and those defined by Fc receptors.