Subpopulations Of Lymphoid Cells Research Articles

Isolation and Characterization of a New Member of the HumanLy6Gene Family(LY6H)

TheLy6family of genes encodes glycosylphosphatidylinositol-anchored cell surface glycoproteins expressed on various types of cells. Intriguing patterns of expression ofLy6genes on specific subpopulations of lymphoid and myeloid cells suggest that Ly6 molecules may be involved in the development and homeostasis of hematopoietic cells. We have isolated a new member of the humanLy6gene family,LY6H,from a human fetal brain cDNA library. Fluorescencein situhybridization and radiation hybrid analyses assignedLY6Hto chromosome 8, where other members of theLy6gene family are also located. Northern analysis revealed thatLY6His highly expressed in particular subdivisions of human brain and also in MOLT-3 and -4 acute lymphoblastic leukemia cells. These data suggest that LY6H may play a role(s) in both the central nervous system and the immune system.

Characterization and phenotypic analysis of differentiating CD34+ human bone marrow cells in liquid culture.

Our current understanding of human haematopoietic stem cell biology is based in part on the characterization of human CD34+ bone marrow cell differentiation in vitro. CD34 is highly expressed on early stem cells and haematopoietic progenitor cells with clonogenic potential and is gradually lost during differentiation and commitment. However, CD71 (transferrin receptor) is expressed at low levels on early stem cells and generally increases during haematopoietic progenitor cell proliferation. We reasoned that the combination of these surface markers would provide a useful framework for the simultaneous analysis of multiple lineage differentiation of CD34+ haematopoietic progenitor cells in liquid culture. In this report, we identify the phenotype of distinct subpopulations of myeloid, erythroid and lymphoid cells in liquid suspension culture using differential expression of CD34 vs. CD71 in combination with specific lineage markers. Freshly isolated human CD34+ bone marrow cells were introduced into suspension culture and monitored over a 6-d period using 3-colour flow cytometry. This is the first demonstration that differential expression of CD34 vs. CD71 can be used to simultaneously monitor differentiation of multiple haematopoietic cell lineages in liquid suspension culture, facilitating the study of cytokine-, drug- or chemical-induced alterations in haematopoietic progenitor cell differentiation in vitro.

Characterisation of monoclonal antibodies specific for sea bass (Dicentrarchus labraxL.) IgM indicates the existence of B cell subpopulations

Three monoclonal antibodies (MAb) against sea bass IgM (Dicentrarchus labraxL.) were selected (WDI 1–3) based on ELISA, Western blot and FACS analysis. Further characterisation was done by immunofluorescence on cytocentrifuge slides and immuno-electron microscopy. All MAb were found to be of the IgG1/|gkisotype and were effective in detectingVibrio anguillarum-ordalii antibody titres with an ELISA. Under denaturing conditions in Western blots, all MAb reacted with a tetrameric, dimeric and monomeric form of serum IgM. Under reducing conditions WDI 1 recognises the heavy (H) chain (±78kDa) and both WDI 2 (slightly) and WDI 3 (strongly) recognise the light (L) chain (±28kDa) in Western blots of whole serum and Protein A isolated sea bass IgM. The average percentages (N=6) of surface IgM+(B) cells in peripheral blood leucocytes (PBL), head kidney, trunk kidney, spleen, thymus and gut for the different MAb were estimated by FACS. The highest was in PBL (33%) stained with WDI 3 and the lowest in thymus (1%). All MAb showed specific immunogold labelling of a subpopulation of lymphoid cells in both PBL and spleen and of plasma cells and some macrophages in spleen. Additional percentage staining in FACS analysis using different combinations of the three MAb, as well as double immunofluorescence staining of cytocentrifuge preparations and Coomassie blue staining of SDS–PAGE of Protein A purified IgM under reduced conditions, strongly suggest the existence of at least two H and L chains expressed in different combinations in at least two subpopulations of B cells in sea bass. From these results it is also concluded that the combination of WDI 1 with WDI 3 stains all or almost all B cells.

Production and characterization of new monoclonal antibodies that distinguish subsets of mink lymphoid cells.

Several hybridoma clones that produce monoclonal antibodies (MAbs) reacting with subpopulations of mink lymphoid cells were established. Two of the MAbs, MTS-4.3 and MTS-9.3, reacted with relatively small populations of surface immunoglobulin (Ig)-negative (Ig-) lymphocytes. MTS-4.3+ and MTS-9.3+ cells were distributed in the thymic cortex and medulla, paracortical areas of lymph nodes, and periarterial lymphoid sheaths of the spleen, indicating that these MAbs identify T lymphocytes. Another MAb, MTB-5.6, reacted with a large proportion of surface Ig+ lymph node cells, but not with surface Ig- cells. In immunohistochemistry this MAb stained dendritic epithelial cells of thymic cortex, large polygonal cells of thymic medulla, a large proportion of lymphocytes in the mantle zone of lymphoid follicles, dendritic-shaped cells of paracortical area, and some lymphocytes and macrophage-like cells of medullary cords and sinuses of lymph nodes. The expression of the cell-surface antigen reacting with MTB-5.6 on Ig+ lymph node cells was increased after concanavalin A stimulation. These new reagents may be useful to analyze cellular basis of the abnormal immune responses observed in Aleutian mink disease, a classical model of human autoimmune diseases.

Lymphoid cell subpopulations containing vasoactive intestinal peptide in the rat

In the present study we describe the cell types containing immunoreactive vasoactive intestinal peptide (IR-VIP) in rat thymus, spleen, and lymph nodes. Indirect immunofluorescence staining and flow cytometry indicated that all lymphoid organs studied contained VIP-positive cells, with the spleen and lymph nodes having a higher proportion than the thymus. Vasoactive intestinal peptide was found in both lymphocytes and nonlymphoid cells, lymphocytes predominating among VIP-positive cells. Double immunofluorescent staining and flow cytometry showed that all lymphoid subpopulations identified contained variable proportions of VIP-positive lymphocytes. Immunocytochemical staining of cell suspensions for both light and electron microscopy showed the cytoplasmic localization of the IR-VIP. These findings, coupled to our previous results, are consistent with the idea that VIP may have a lymphoid origin and could be active in local immune responses.

Strain-dependent migration of CD4 and CD8 lymphocyte subsets to lymph nodes in NOD (nonobese diabetic) and control mice.

Subpopulations of lymphoid cells were compared with respect to their ability to migrate into peripheral lymphoid organs of nonobese diabetic (NOD) mice and various strains of control mice. In short-term, in vivo homing studies, no major differences in the pattern of homing of B and T cells were observed among all mouse strains studied. On the other hand, CD4 cells localized consistently more efficiently than CD8 cells in both PP and LN of adult NOD and BALB/c mice, whereas both populations migrated roughly equivalently in LN of adult DBA/2, CBA, and C57BL/6 mice. No age-dependent differences in the homing of CD4 and CD8 cells were observed in BALB/c mice. On the contrary, in 2-week-old NOD mice, CD4 and CD8 cells migrated equally well. The preferential entry of CD4 cells in adult NOD and BALB/c did not result from increased blood transit time of CD8 cells. On the other hand, the preferential migration of CD8 cells was observed in the liver, whereas the two T-cell subsets migrated equally well in the lungs. The differences in the homing characteristics of CD4 and CD8 cells among NOD, BALB/c, and C57BL/6 mice were not related to modifications in the level of expression of adhesion molecules such as MEL-14, LFA-1, and Pgp-1.

Induction of αvβ3 integrin-mediated attachment to extracellular matrix in β1 integrin (CD29)-negative B cell lines

β 1 integrin containing complexes have been implicated as the primary adhesion structures in many lymphocyte extracellular matrix (ECM) interactions. However, many B lymphocytes lack surface expression of the β 1 subunit, implying that this subpopulation of lymphoid cells must employ alternate adhesion structures if they are to maintain an interactive capacity with ECM. An examination of the adherence properties of the β 1 integrin-negative B cell line JY indicated that these cells exhibit little or no basal adherence to any of the ECM components examined. However, these cells could be induced to adhere to the ECM components fibronectin, laminin, and vitronectin following treatment with PMA. Blocking studies with monoclonal antibodies indicated the α v β 3 integrin complex was involved in the attachment to each of these ligands. However, the adherence to fibronectin displayed a complex pattern of inhibition suggesting the involvement of other ECM receptors. The utilization of the α v β 3 complex was not unique to the JY cell line. Other B cell lines were observed to employ α v β 3, and these lines similarly lacked expression of β 1 integrin. These results indicate that α v β 3 can act as a lymphoid ECM-adhesion structure which may provide an alternative means for lymphocytes to interact with ECM. Furthermore, these studies provide evidence for the presence of lymphoid-associated α v β 3 integrins with regulatable activity, which contrasts with the constitutive adhesive potential of these complexes when present on other cell types.

The production of growth hormone and insulin-like growth factor-I by the same subpopulation of rat mononuclear leukocytes

In the present study, we evaluated the subpopulation of lymphoid cells from normal and hypophysectomized rats producing GH and IGF-I in vitro. The data show that removal of the pituitary results in depression of GH production in spleen, thymus, and bone marrow and an increase in the peripheral blood leukocytes. The changes in the percentage of cells producing GH in hypophysectomized animals are not due to a single cell type but appears to influence the T-helper, T-cytotoxic, and B-cell subsets. Interestingly, no significant changes in the levels of GH RNA were detected between control and hypophysectomized animals after the in vitro culture. We also found that the increase in GH production in spleen cell cultures after mitogen stimulation could be accounted for by an increase in the percentage of T cells producing GH. Lastly, we demonstrated that the cells positive for GH production were also positive for IGF-I production. This later finding coupled with our previous results suggest that an autocrine regulatory circuit may be important for the production of leukocyte-derived irGH and irIGF-I within the immune system.

Thymopentin in Sézary syndrome.

Response to the treatment of Sézary syndrome (a cutaneous T-cell lymphoma) is poor. Since patients with this syndrome are elderly, aggressive chemotherapy is poorly tolerated and deep immunodepression may result in fatal opportunistic infections. Immunomodulating therapy seems important in the management of Sézary syndrome. In a pilot study, we assessed the efficacy of thymopentin (TP-5), a synthetic pentapeptide, correlating clinical responses to the histologic and immunologic effects of the drug. Twenty Sézary syndrome patients received 50 mg TP-5 intravenously three times a week for a mean time of 16.3 months. Skin and lymph node histology and immunohistochemistry, circulating lymphoid cell subpopulations, and soluble interleukin-2 receptors were evaluated before treatment and during follow-up. Eight complete remissions and seven partial remissions were obtained (75%). No change was observed in three patients, and disease progression was observed in two patients. The median duration of response was 22 months (complete remission, 25.5 months; partial remission, 14 months). Four-year survival probability was 53.9%. The responses were obtained when circulating Sézary cells were less than 2600/mm3. A significant reduction of CD4+ cells paralleled a CD8+ cell increase. An increase in NK cells (CD16+ and CD56+) was accompanied by significantly longer survival. Serum soluble interleukin-2 receptor values were a useful monitor of the clinical course and treatment. Loss of epidermotropism, reduction of Langherhans' cells, and HLA-DR+ keratinocytes were found. TP-5 is a potentially useful agent in the treatment of a subgroup of patients with Sézary syndrome; its activity seems to be mediated by an effect on a normal NK cell-like subpopulation. The biological and clinical role of this therapy in combination with conventional treatments will be the subject of future investigations.

Renal cell carcinoma.

The behavior of renal cell carcinoma remains one of the most unpredictable of the genitourinary neoplasms. Once this disease has spread beyond the confines of the kidney, it is extremely difficult to control. This year, emphasis has focused on the characteristic cytogenetic and chromosomal changes that are seen in this tumor that help to explain partially its enigmatic behavior. Immunotherapy remains the mainstay of nonsurgical therapy. Recent studies have examined the efficacy of using combinations of interferons, interleukin-2, or specific subpopulations of lymphoid cells to control metastatic renal cell carcinoma. The role of surgery in metastatic disease, tumor extending into the vena cava, and parenchyma-sparing operations continues to be examined. This review examines the most recent literature on each of these aspects in the treatment of this difficult and challenging tumor.

Expression of CD31 epitopes on human lymphocytes: CD31 monoclonal antibodies differentiate between naive (CD45RA+) and memory (CD45RA‐) CD4‐positive T cells

The CD31 antigen, a member of the immunoglobulin superfamily with a possible cell adhesion function, is expressed on approximately 50% of peripheral blood lymphoid cells at relatively low intensity (10-20% of the level on monocytes). In the accompanying paper we showed that a mAb, 5A2.G5, which identifies a glycosylation-dependent epitope of the CD31 antigen, bound to fewer lymphocytes than two other CD31 mAb, B2B1 and 2BD4, although the 3 antibodies bound equally well to monocytes. We have now analyzed the pattern of expression of epitopes of the CD31 antigen on lymphoid cell subpopulations using two-color immunofluorescence and flow cytometry. Large granular lymphocytes (CD16+), CD8-positive T cells and B cells (SMIg+) were mostly CD31-positive as indicated by the binding of mAb B2B1 and 2BD4. Single populations displaying some overlap with the negative control were obtained in each case. In contrast, CD4-positive T cells fell into two discrete populations with respect to CD31 antigen expression. mAb 5A2.G5 displayed weaker binding to all lymphoid cell types, indicating that the pattern of glycosylation of the CD31 antigen differs between lymphocytes (of all types) and cells of the myeloid lineages. The heterogeneity of CD31 antigen expression by CD4-positive cells was further examined by dual-labelling of purified CD4 cells with mAb B2B1 and CD45RA or CD29 mAb which identify naive and memory T cells respectively. The CD31 antigen was found to be preferentially expressed by the CD45RA-positive, naive cell population.

The production of growth hormone by subpopulations of rat mononuclear leukocytes

In this study we analyzed the production of GH mRNA and secretion of GH by purified subpopulations of rat lymphoid cells. The data demonstrate that mononuclear leukocytes from various tissues, including spleen, thymus, bone marrow, Peyer's patches, and peripheral blood, all have the ability to produce GH mRNA and secrete GH. Data obtained with cells separated by adherence, nylon wool columns, and positive and negative sorting with monoclonal antibodies that define B, monocyte, T helper and T cytotoxic cells show that several different cell types have the ability to produce GH mRNA. The results suggest that B cells, macrophages, and T helper cells produce more GH mRNA and protein than that of T cytotoxic cells. Natural killer (NK) cells also produce detectable levels of GH mRNA and protein. To validate that leukocyte GH RNA produced in vitro was similar in structure to pituitary GH RNA, we studied the RNA by reverse transcription and the polymerase chain reaction. A sample of the PCR reaction products, analyzed by gel electrophoresis, showed a single major DNA band corresponding in length (600 base pairs) to the distance between the 5′ ends of the two GH-specific primers. The DNA band was specifically labeled with a GH-specific probe after Southern transfer to nitrocellulose. Leukocyte GH purified by immunoaffinity chromatography from culture fluids was shown to be bioactive based on its ability to stimulate the incorporation of tritiated thymidine in primary rat spleen cell cultures. The bioactivity could be blocked with specific antibodies to rat GH. Taken together, the data suggest that there is heterogeneity within lymphocytes regarding their ability to produce GH and are consistent with the idea that GH may be active in local immune responses.

Suppression of T lymphocyte subpopulations by THC.

THC (delta-9-tetrahydrocannabinol) is considered the major psychoactive component of marijuana. It is widely acknowledged that THC can depress various parameters of the immune response. These parameters include lymphocyte proliferation, macrophage spreading, and antibody production (1–3). Studies have suggested that THC has different magnitudes of effect depending on the lymphoid organ analyzed (2) as well as the age of the animal (4). Different lymphoid organs of adult mice as well as identical organs from mice of various ages have unique proportions of lymphoid cell subpopulations. This study examines the effect of THC on lymphoid cell subpopulations using the lymphoblastogenic assay (LBT) as well as analysis of cell subpopulations by the fluorescent activated cell sorter (FACS).KeywordsSpleen CellFluorescent Activate Cell SorterLymphoid OrganIdentical OrganFluorescent Activate Cell Sorter AnalysisThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Determination of mixed chimerism by a simple flow cytometry method

A simple, sensitive and accurate method was developed to determine the level of lymphoid chimerism in bone marrow-transplanted rodents. The method is based on flow cytometry using polyclonal alloantisera and labeled second step anti-IgG antibodies. Using mixtures of spleen cells from different mouse strains, it was demonstrated that low levels of chimeric cells (less than 1%) could easily be detected. Moreover, using two-color fluorescence analysis, the level of chimerism could also be determined in subpopulations of lymphoid cells, e.g., CD4 or CD8 cells and was found to be identical to the results obtained in unseparated lymphoid populations. The method was compared to the complement dependent cytotoxicity assay (CDCA) and to the flow cytometric determination of chimerism using labeled monoclonal antibodies against specific MHC antigens. CDCA was found to be more labor intensive and could only estimate the composition of the cell mixtures without detecting low levels of chimerism (< 5%). The results of flow cytometry, using directly labeled monoclonal antibodies or polyclonal antibodies with second step reagents, were identical. It is concluded that, due to its simplicity and high sensitivity, the method described permits reliable determination of the level of mixed chimerism in rodents and is an excellent alternative when no anti-MHC mAbs are available.

In vivo dynamics of pulmonary lymphoid cell subpopulations generated against pulmonary metastasis: evaluation by broncho alveolar lavage fluid

The dynamics of lymphoid cell subpopulations in bronchoalveolar lavage fluid (BALF) and the systemic lymphoid organs of mice after intravenous injection of B16 melanoma cells were examined with a fluorescence-activated cell sorter. The lymphoid cell subpopulations of BALF and mediastinal lymph nodes showed significant changes in numbers and proportions, while those of other lymphoid organs including inguinal lymph nodes, thymus and spleen, showed little change. In week 1, the cells with a Thy-1.2+, Lyt-1+, L3T4-, Lyt-2- phenotype and asialo-Gm1+ cells in BALF significantly increased and L3T4+ cells slightly increased in number. By week 3, the numbers of Lyt-2+ cells in BALF markedly increased in number (by about 90 times) compared with controls. The number of Thy-1.2+ cells in mediastinal lymph nodes also increased significantly by week 3. Mice that had been pretreated with an immunosuppressive dose of cyclophosphamide were also inoculated intravenously with B16 melanoma cells. In these mice, a significantly increased number of pleural tumors developed and the number of Thy-1.2+ cells in BALF was markedly reduced from week 1 to 3. The results indicate that L3T4 and Lyt-2 double negative T-cells and natural killer (NK) cells may be generated and/or mobilized to the lung in an early phase of experimental metastasis of B16 melanoma cells and that at a later stage, when multiple metastases develop, T-cells with a Lyt-2+ phenotype markedly increase, probably as an expression of a host reaction against proliferating metastatic tumor cells.

Preferential infiltration of macrophages during early stages of insulitis in diabetes-prone BB rats.

The subpopulation of lymphoid cells at the different stages of insulitis in BB rats was determined by immunohistochemical techniques with various monoclonal antibodies, including the recently developed OX41, which distinguishes macrophages from T-lymphocytes, OX19 for pan-T-lymphocytes, W3/25 for both helper T-lymphocytes and macrophages, OX8 for cytotoxic T-lymphocytes and natural killer cells, and OX12 for B-lymphocytes. The major population of infiltrated cells found during the early stages of insulitis appeared to be macrophages. This preceded invasion by a mixed population of cells, including both T- and B-lymphocytes and/or natural killer cells. The preferential infiltration of macrophages during the early stages of insulitis strongly suggested that there might be an initial change in the target beta-cells that precedes their immune destruction, although the amplification of immune response by activated T-lymphocytes and natural killer cells at a later stage seemed to be required for the clinical expression of the disease.

Effects of transforming growth factor-beta on human lymphokine-activated killer cell precursors. Autocrine inhibition of cellular proliferation and differentiation to immune killer cells.

With subpopulations of human lymphoid cells that were enriched for lymphokine-activated killer (LAK) cell precursors, studies were performed to examine the effects of transforming growth factor-beta (TGF-beta) on their IL-2-dependent growth and differentiation to killer cells. The majority of the LAK precursor cells appeared to reside in nonadherent, non-T, and non-B lymphocyte populations that expressed CD11 and CD16 Ag. These cells were induced to proliferate and become LAK cells by high concentrations of rIL-2 alone in the apparent absence of any prior activation with mitogen or Ag. The partially purified lymphocyte subpopulations generated varying but several-fold greater levels of LAK killing on a per cell basis than did unfractionated lymphocytes. The exogenous addition of TGF-beta to the LAK precursor cultures, markedly inhibited IL-2-stimulated growth as well as the development of LAK activity in a dose-dependent manner. The antimitotic effect of TGF-beta was reversible; inhibition of proliferation could be largely restored by increasing the concentration of IL-2 in culture. In contrast, TGF-beta inhibition of cytotoxicity was relatively independent of the concentration of IL-2. Further, LAK precursors constitutively expressed TGF-beta mRNA and high affinity receptor for TGF-beta. Activation of LAK precursors with IL-2 alone, resulted in a three- to fivefold up-regulation of intracellular TGF-beta mRNA and TGF-beta biologic activity secreted in the culture media. Furthermore, Northern blotting revealed that the resting LAK precursors did not express the Tac-mRNA. Receptor binding studies with 125I-IL-2 suggested the presence of a single class of IL-2R with an apparent Kd of intermediate range (beta-chain of IL-2R) on the unstimulated cells. Stimulation with high concentrations of Il-2 induced Tac-mRNA (both the 3.5- and 1.5-kb transcripts) and resulted in the expression of high affinity IL-2R (Kd approximately 10(-11) M) on these cells. Suppression of IL-2-dependent responses by TGF-beta was accompanied by a selective down-regulation of the 1.5-kb Tac-mRNA as well as by reduction in high affinity IL-2R. The results suggest a negative autocrine control of TGF-beta on IL-2-dependent growth and differentiation of human LAK cells, possibly related to regulate the killer activation function.

Fine-needle aspiration biopsy in the monitoring of liver allografts. II. Applications to human liver allografts.

Serial fine-needle aspiration biopsies (FNAB) were used for clinical monitoring of human liver allografts. Nine liver allograft recipients were monitored with FNAB at 1-3 day intervals. No complications were recorded. All patients underwent at least 1 inflammatory episode of acute rejection; altogether 11 episodes, all reversible, were recorded. The inflammatory infiltrate consisted mainly of lymphoid cells, including lymphoid blasts, with minor involvement of monocytes, monoblasts, and macrophages. Further analysis of lymphoid cell subpopulations by immunoperoxidase techniques demonstrated an increase of T cells during rejection, both the CD4 (T4) and CD8 (T8) subsets were increased. A slight increase of B cells in the graft was also seen. The CD4/CD8 (T4/T8) ratio was first low, peaked at the onset, and decreased toward the end of the episode. No clear correlations to the intragraft cellular events were recorded in corresponding blood specimens. However, an episode of eosinophilia was seen in the blood at the beginning of rejection, correlating with fever in the recipient. Degenerative changes in the parenchymal cells and bile droplets in the hepatocytes, indicating cholestasis and hepatocyte damage, were seen during all episodes of rejection, and these changes persisted even 10 days after the inflammation had subsided. The FNAB-findings correlated well with biochemical laboratory parameters, but the diagnosis of rejection could be established by the FNAB already 1-5 days earlier than elevated serum values indicated liver dysfunction.

Fine-needle aspiration biopsy in the monitoring of liver allografts. I. Correlation between aspiration biopsy and core biopsy in experimental pig liver allografts.

We have used allogeneic pig liver transplants to investigate the structure of inflammation in acute liver allograft rejection. An inflammatory episode of acute cellular rejection was observed in 9/10 allografts in nonimmunosuppressed recipients, when monitored with simultaneous fine-needle aspiration biopsies (FNAB) and core needle biopsies (NB). The intensity of inflammation in FNAB was quantitated using the corrected increment method and correlated with NB findings. In FNAB, all inflammatory episodes were detected on the 4th day after transplantation with lymphoid blast and lymphocyte infiltration, later accompanied by monocytes and macrophages. Maximal intensity of inflammation was recorded in FNAB on day 14. In NB, histology demonstrated distinct inflammation in the portal area on day 4. The predominantly lymphocytic infiltration, also containing varying numbers of plasma cells, eosinophils, neutrophils and macrophages, reached its maximum 7-14 days after transplantation. With the indirect immunoperoxidase technique, lymphoid cell subpopulation analysis of FNAB demonstrated an increase of both T4 and T8 cells during rejection. The T4/T8 ratio was first low, and increased at the beginning of the episode, on day 4, but decreased again on days 7 and 14. The number of B cells in the graft was also elevated during rejection. The cellular changes in the corresponding blood specimens followed approximately the same lines, although the changes were less prominent. NB immunohistology, using immunoperoxidase and frozen sections, correlated well with FNAB results, and demonstrated a T4 predominance in the portal area on day 4 but a T8 predominance on days 7 and 14. In addition to lymphoid cells, macrophages/granulocytes were also frequent in the portal area and scattered in the parenchyma on days 7 and 14. An additional inflammatory cell component in liver allograft rejection, detectable only in the NB, was eosinophils in the portal area, recorded in maximum on day 14. Taken together, the inflammatory changes in the FNAB and NB were similar, and time-related changes of cellular infiltrate in FNAB and NB correlated closely.

Central catecholamine neurotoxin administration: 1. Immunological changes associated with the suppression of experimental autoimmune encephalomyelitis

Central nervous system (CNS) depletion of norepinephrine (NE) using 6-hydroxydopamine (6-OHDA) prior to disease induction suppressed the clinical signs of experimental autoimmune encephalomyelitis (EAE). This treatment did not have an effect on the degree of mononuclear cell infiltration when spinal cord sections were examined and stained with hematoxylin and eosin, nor on serum levels of anti-myelin basic protein antibodies. However, investigation of the subpopulations of lymphoid cells within the perivascular lesions showed an increase in cells bearing the T suppressor cell phenotype, OX8 +, in the 6-OHDA-treated EAE rats when compared to saline-control-treated EAE rats. Examination of other cellular subsets showed no differences in the numbers of T helper cells, macrophages, or B cells within the lesions of the two groups. Furthermore, histofluorescent estimation of catecholamines in spinal cord sections from 6-OHDA- and saline-control-treated EAE rats demonstrated that catecholamines were indeed depleted in the rats with suppressed clinical EAE. These findings suggest that 6-OHDA depletion of CNS NE may remove an effector amplification mechanism, or trigger a T suppressor cell mechanism, or both, leading to suppression of the effector phase of EAE, clinical paralysis.