Proportions Of Lymphocyte Subpopulations Research Articles

Influence of Heterologous and Homologous Vaccines, and Their Components, on the Host Immune Response and Protection Against Experimental Caprine Paratuberculosis.

Vaccination against paratuberculosis, a chronic disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map), has been considered as the most effective control method. However, protection is incomplete, and the mechanisms operating in the response of the animals to vaccination are not fully understood. Therefore, this study analyzed the immune response and the effects on protection against Map infection, elicited by paratuberculosis (Silirum®) and tuberculosis (heat-inactivated M. bovis [HIMB]) vaccines and their components in a caprine experimental model. Fifty goat kids were divided into 10 groups (n = 5) according to their vaccination (Silirum®, HIMB and nonvaccinated), immunization (inactivated bacteria or adjuvant), and/or infection. Oral challenge with Map was performed 45 days postvaccination/immunization (dpv), and animals were euthanized at 190 dpv. Peripheral immune response and proportion of lymphocyte subpopulations were assessed monthly by enzyme-linked immunosorbent assay and flow cytometry analysis, respectively. Local immune response, proportion of tissue lymphocyte subpopulations, Map detection (polymerase chain reaction), and histological examination were conducted in gut-associated lymphoid tissues. All infected groups developed paratuberculosis granulomatous lesions despite vaccination or immunization. The Silirum® and HIMB-vaccinated groups showed a considerable lesion reduction consistent with a significant peripheral cellular and humoral immune response. Besides, a lower number of granulomas were observed in groups immunized with inactivated bacteria and adjuvants in comparison to nonvaccinated and infected group. However, despite not being significant, this reduction was even higher in adjuvant immunized groups, which developed milder granulomatous lesion with no detectable peripheral immune responses associated with immunization. No changes in the peripheral and local proportion of lymphocyte subsets or local immune response were detected in relation to either vaccination/immunization or infection. Despite that paratuberculosis and tuberculosis vaccination showed a partial and cross-protection against Map infection, respectively, only histological examination could assess the progression of infection in these animals. In addition, the pattern observed in the reduction of the lesions in adjuvant immunized groups suggests the possible involvement of a nonspecific immune response that reduces the development of granulomatous lesions.

IN VIVO BIODOSIMETRY OF PORCINE T-LYMPHOCYTE SUBSETS AND NK CELLS.

The aim of the present study was to evaluate the biodosimetric potential of peripheral blood lymphocytes, particularly of T-cell subsets (null and T helper) and natural killer cells (NK), upon exposure to gamma irradiation (60Co) in vivo. For this purpose, the change in relative numbers of NK cells and T-lymphocyte subsets, as well as in the H2AX phosphorylation rate, were evaluated as potential early markers of the lymphocytic response to irradiation in vivo. These experiments were performed on a Large White Pig model. As a result, significant but not dose-dependent changes in the proportion of lymphocyte subpopulations (NK cells, null and T helper cells) were found after exposure to ionising radiation in vivo. On the other hand, circulating NK cells showed relatively higher radioresistance capacity when compared to the T-lymphocyte subsets; however, gamma-H2AX expression showed no significant difference between the evaluated lymphocyte subsets.

Elevated peripheral blood B lymphocytes and CD3+CD4-CD8- T lymphocytes in patients with non-small cell lung cancer: A preliminary study on peripheral immune profile.

It has been established that the tumor microenvironment (TME) has a crucial role in enabling tumors to evade from host immune responses. Previous studies demonstrated that tumor cells are not only able to reshape immune milieu at the tumor site, but also exert systemic effects, which has been demonstrated to be important for metastasis. At present, how the peripheral immune environment change in the tumor-bearing host is unclear. The present study identified a number of changes in the proportions of lymphocyte subpopulations and the levels of cytokines in patients with NSCLC, which may provide a preliminary profile of the immune environment in the peripheral blood of patients harboring a tumor. These findings expand on the present knowledge on how tumors can alter the immune system to benefit its growth and metastasis, which may provide a potential novel strategy for immunotherapy.

Maternal cigarette smoking and its effect on neonatal lymphocyte subpopulations and replication

BackgroundSignificant immunomodulatory effects have been described as result of cigarette smoking in adults and pregnant women. However, the effect of cigarette smoking during pregnancy on the lymphocyte subpopulations in newborns has been discussed, controversially.MethodsIn a prospective birth cohort, we analyzed the peripheral lymphocyte subpopulations of smoking (SM) and non-smoking mothers (NSM) and their newborns and the replicative history of neonatal, mostly naive CD4 + CD45RA + T cells by measurements of T-cell-receptor-excision-circles (TRECs), relative telomere lengths (RTL) and the serum cytokine concentrations.ResultsSM had higher lymphocyte counts than NSM. Comparing SM and NSM and SM newborns with NSM newborns, no significant differences in proportions of lymphocyte subpopulations were seen. Regardless of their smoking habits, mothers had significantly lower naive T cells and higher memory and effector T cells than newborns. NSM had significantly lower percentages of CD4 + CD25++ T cells compared to their newborns, which was not significant in SM. There were no differences regarding cytokine concentrations in newborns of SM and NSM. However, NSM had significantly higher Interleukin-7 concentrations than their newborns. Regardless of smoking habits of mothers, newborns had significantly longer telomeres and higher TRECs than their mothers. Newborns of SM had significantly longer telomeres than newborns of NSM.ConclusionsApart from higher lymphocyte counts in SM, our results did not reveal differences between lymphocyte subpopulations of SM and NSM and their newborns, respectively. Our finding of significantly longer RTL in newborns of SM may reflect potential harm on lymphocytes, such as cytogenetic damage induced by smoking.

Immunological adjuvant efficacy of glycyrrhetinic acid liposome against Newcastle disease vaccine

The aim of this study is to investigate whether the activity of inducing immune response of glycyrrhetinic acid (GA) could be enhanced after GA was encapsulated with liposome. Three hundred and fifty 14-day-old chickens were randomly assigned to 7 groups and vaccinated with Newcastle disease (ND) vaccine. Simultaneously, the chickens in experimental groups were injected with the glycyrrhetinic acid liposome (GAL) at three doses, GA and blank liposome, respectively. The activity of serum antibody titer, concentrations of immunoglobulins G (IgG) and immunoglobulins M (IgM), lymphocytes proliferation, the proportions of lymphocyte subpopulations (CD4(+) and CD8(+)) was determined after vaccination. GAL was evaluated for inducing humoral immunity and cellular immunity in chicken against Newcastle disease (ND) vaccine. The results showed that GAL not only could significantly enhance the antibody titers, IgG and IgM in ND vaccine immunized chicken, but also significantly promote the lymphocyte proliferation and the proportions of CD4(+) and CD8(+), as comparison with GA, BL and VC control groups. Moreover, the effects appear a dose-dependent manner and a time-dependent manner. These indicated that GAL could significantly promote the activation potential of humoral immunity and cellular immunity in chicken and present certain dose-effect and time-effect relationships. The formulations of GA and liposome can further enhance the immune response against ND vaccine compared with the adjuvant alone.

Semi-supervised Nonnegative Matrix Factorization for gene expression deconvolution: A case study

Heterogeneity in sample composition is an inherent issue in many gene expression studies and, in many cases, should be taken into account in the downstream analysis to enable correct interpretation of the underlying biological processes. Typical examples are infectious diseases or immunology-related studies using blood samples, where, for example, the proportions of lymphocyte sub-populations are expected to vary between cases and controls.Nonnegative Matrix Factorization (NMF) is an unsupervised learning technique that has been applied successfully in several fields, notably in bioinformatics where its ability to extract meaningful information from high-dimensional data such as gene expression microarrays has been demonstrated. Very recently, it has been applied to biomarker discovery and gene expression deconvolution in heterogeneous tissue samples.Being essentially unsupervised, standard NMF methods are not guaranteed to find components corresponding to the cell types of interest in the sample, which may jeopardize the correct estimation of cell proportions. We have investigated the use of prior knowledge, in the form of a set of marker genes, to improve gene expression deconvolution with NMF algorithms. We found that this improves the consistency with which both cell type proportions and cell type gene expression signatures are estimated. The proposed method was tested on a microarray dataset consisting of pure cell types mixed in known proportions. Pearson correlation coefficients between true and estimated cell type proportions improved substantially (typically from about 0.5 to approximately 0.8) with the semi-supervised (marker-guided) versions of commonly used NMF algorithms. Furthermore known marker genes associated with each cell type were assigned to the correct cell type more frequently for the guided versions. We conclude that the use of marker genes improves the accuracy of gene expression deconvolution using NMF and suggest modifications to how the marker gene information is used that may lead to further improvements.

Changes of blood count, lymphocyte subpopulations and immunoglobulin levels in nephroblastoma long term survivors

The aim of this study was to investigate the frequency of blood count, lymphocyte subpopulations, and immunoglobulin levels alterations in a group of healthy nephroblastoma long-term survivors. The group included 122 nephroblastoma longterm survivors who were at least five years post anticancer therapy and free of any sign of recurrence The proportion of lymphocyte subpopulations was analyzed by flow cytometry using antibodies anti CD45 FITC/CD14 PE, anti CD3 FITC/ CD16+CD56 PE, anti CD4 FITC/ CD8 PE and anti CD20 FITC. Immunoglobulin G, A, and M levels were evaluated by immunoturbidimetry. Total blood count was also examined. The occurrence of decreased immunoglobulin levels, leukocytes, lymphocytes, and granulocytes count, proportion of T lymphocytes and their CD4+ subpopulation are not frequent. The most frequently decreased lymphocyte subpopulation was CD8 (15.5%). The most frequent abnormal findings were increased proportion of NK cells (38.5 %), B lymphocytes (38,52 %), decreased number of erythrocytes (25.2 %), hemoglobin levels (41.7 %) and hematocrit (13.9 %). The only significant differences between results of immunological examination and course of the disease were more frequently decreased proportion of CD4+ lymphocytes in recurrent disease survivors and lower IgA levels in survivors after radiotherapy. We found decreased at least one immunological parameter in one fifth of the survivors. The most frequently altered parameter was hemoglobin, which was decreased in 41.7 % of survivors. Decraesed hemoglobin may worsen quality of survivors life. Key words: nephroblastoma long-term survivors, blood count, lymphocyte subpopulations, immunoglobulin G, A, M serum levels.

Adenoid as a source of lymphocytes in the surface secretions of nasopharynx

The significance and protective efficacy of surface secretions on mucosal membranes in the upper airways are well recognized. The aim of our study was to reveal the role of the adenoids as a source of cellular components in the mucosal secretion. The adenoid removed because of its hypertrophy and the samples of surface secretions taken by "imprint method" described by Ebenfelt et al. from the group of 38 children were examined by flow cytometry. The lymphocyte subsets with following antigens: CD3, CD4, CD8, CD19, CD23, CD16+56, CD45RA, CD45RO, HLA-DR were analyzed. Two groups were studied: (1) AH, children with adenoid hyperplasia without otitis media; (2) OME, children with adenoid hyperplasia and persistent otitis media with effusion. Age-related changes in percentages of lymphocyte subpopulations were analyzed. The percentage of lymphocyte subsets in adenoid and secretion were similar, however, in the surface secretion there was higher proportion of lymphocytes B and NK and lower of T. There was no correlation between percentages of lymphocyte in adenoid and surface secretion except for lymphocytes Th with memory phenotype and lymphocytes B with marker CD23(+). In adenoid the percentage of T and Th lymphocytes increased with age and the percentage of B lymphocytes decreased. In the secretion age-related changes were less pronounced and only the percentage of lymphocytes B CD23(+) showed positive correlation with age. In cases of otitis media with effusion there was higher proportion of lymphocytes B (CD19(+) and CD19(+)CD23(+)) and lower of lymphocytes Ts and Th with naive phenotype in the secretion. In adenoid however, the cases of OME revealed lower percentage of lymphocytes B and higher of lymphocytes Ts. Similar proportions of lymphocyte subpopulations in surface secretion and in adenoid imply that adenoid is the source of those cells. However, lack of correlation between the percentages of lymphocytes in secretion and in adenoid suggest that the process of lymphocyte migration has active and selective character.

Increased proportion of Fas positive CD8+ cells in peripheral blood of patients with COPD

Chronic obstructive pulmonary disease (COPD) is characterised by chronic inflammation in pulmonary tissue and is also associated with systemic effects. The objective of this study was determination of lymphocyte subpopulation and the expression of Fas receptor on lymphocytes derived from peripheral blood of patients with stable COPD (n=18) and a control group: asymptomatic smokers (n=12) and non-smokers (n=12). Flow cytometry method with monoclonal antibodies was used for evaluation of lymphocyte subsets: CD4+ and CD8+ and the expression of Fas (CD95) on T lymphocytes. We found an elevated proportion of CD8+ cells in the blood of COPD patients. Proportion of Fas+ T lymphocytes was significantly higher in patients with COPD when compared with asymptomatic smokers and non-smokers (mean: 84.4% vs. 71.6% vs. 61.0% for Fas+/ CD4+ and 88.1% vs. 73.8% vs. 58.3% for Fas+/CD8+ lymphocytes). The proportion of Fas positive CD8+ cells significantly correlated with the degree of airway obstruction and hypoxemia. The significant correlations of Fas positive CD4+ and Fas positive CD8+ with smoking history expressed as pack years smoked were observed. Our observation of an elevated proportion of circulating lymphocytes bearing Fas receptor may play a role in induction of these cells' apoptosis and indicate the role of Fas/ FasL pathway in the changes in proportion of lymphocyte subpopulations in patients with COPD.

Assessment of lymphocyte subpopulations and cytokine secretion in children exposed to arsenic

Exposure of several human populations to arsenic has been associated with a high incidence of detrimental dermatological and carcinogenic effects. To date, studies examining the immunotoxic effects of arsenic in humans, and specifically in children, are lacking. Therefore, we evaluated several parameters of immunological status in a group of children exposed to arsenic through their drinking water. Peripheral blood mononuclear cells (PBMCs) of 90 children (6 to 10 years old) were collected. Proportions of lymphocyte subpopulations, PBMC mitogenic proliferative response, and urinary arsenic levels were evaluated. Increased urine arsenic levels were associated with a reduced proliferative response to phytohemaglutinin (PHA) stimulation (P=0.005), CD4 subpopulation proportion (P=0.092), CD4/CD8 ratio (P=0.056), and IL-2 secretion levels (P=0.003). Increased arsenic exposure was also associated with an increase in GM-CSF secretion by mononucleated cells (P=0.000). We did not observe changes in CD8, B, or NK cell proportions, nor did we observe changes in the secretion of IL-4, IL-10, or IFN-gamma by PHA-activated PBMCs. These data indicate that arsenic exposure could alter the activation processes of T cells, such that an immunosuppression status that favors opportunistic infections and carcinogenesis is produced together with increased GM-CSF secretion that may be associated with chronic inflammation.

Biotin Deficiency Blocks Thymocyte Maturation, Accelerates Thymus Involution, and Decreases Nose-Rump Length in Mice

Biotin deficiency in experimental animals causes low body weight as well as several phenomena suggestive of an altered immune system. We reported previously that chronic biotin deficiency in mice decreases body weight and alters the number and proportion of lymphocyte subpopulations in the spleen. To further characterize the effects of biotin deficiency, we studied in detail the maturation of thymocytes and the status of biotin in the thymus, as well as the body length of biotin-deficient mice. Male Balb/cAnN mice were fed for up to 20 wk either standard control diet, a biotin-deficient diet, or a biotin-sufficient diet. At different times, nose-rump length, weight of the thymus, spleen and liver, total number of cells in the spleen and thymus, pyruvate carboxylase (PC) and propionyl CoA carboxylase (PCC) activity in thymus cells, and the proportion of distinct thymocyte subsets were determined. These variables did not differ between mice fed the control and biotin-sufficient diets. In contrast, biotin-deficient mice differed from biotin-sufficient mice in all of the analyzed variables. PC and PCC specific activities of thymocytes of mice fed the biotin-depleting diet decreased during the first 4 wk by 84.5%. The maturation of thymocytes in biotin-deficient mice was arrested at the double-negative stage. Our results suggest that biotin deficiency in mice causes an accelerated involution of the thymus and decreases nose-rump length, but these effects do not correlate in magnitude or in temporality with the sharp decrease in the activity of the biotin-dependent carboxylases. As such, the possibility that the aforementioned effects are not related directly to the prosthetic function of biotin should be considered.

A new mutation, ataxia and male sterility (ams), of autoimmune‐prone MRL/lpr mouse is not linked to lpr gene but associated with reduction of spleen size and alteration of lymphocyte subpopulations

We describe changes in the immune system of the newly established mutant line, ataxia and male sterility (AMS) mouse, and that the putative ams mutation is independent of lpr but seemed to affect lymphoproliferation in its mother strain, MRL/lpr. The mean weights of the spleen and lymph nodes of ams-lpr double-homozygous mouse were reduced compared with lpr single-homozygous mouse. Comparison between ams single-homozygous and control mice revealed 45-50% reduction of the spleen weight in the former for which reduction of the number of nucleated cells contributed greatly. In the lymphocyte/monocyte fraction of the spleen, there were significant changes in the proportion of lymphocyte subpopulations, with a reduction of B cells, an increase in CD4 and CD8 T cells, and a decrease in the CD4 : CD8 ratio. In vitro response of splenocytes to concanavalin A showed inconspicuous dose- and time-dependent responses in ams homozygous spleen, suggesting functional alteration of the immunological response. Our results indicate that ams mutation affects the immune system in addition to its two other major effects on the central nervous system and male reproductive system.

Novel quantitative trait loci controlling development of experimental autoimmune encephalomyelitis and proportion of lymphocyte subpopulations.

The B10.RIII mouse strain (H-2(r)) develops chronic experimental autoimmune encephalomyelitis (EAE) upon immunization with the myelin basic protein 89-101 peptide. EAE was induced and studied in a backcross between B10.RIII and the EAE-resistant RIIIS/J strain (H-2(r)), and a complete genome scan with microsatellite markers was performed. Five loci were significantly linked to different traits and clinical subtypes of EAE on chromosomes 1, 5, 11, 15, and 16, three of the loci having sex specificity. The quantitative trait locus on chromosome 15 partly overlapped with the Eae2 locus, previously identified in crosses between the B10.RIII and RIIIS/J mouse strains. The loci on chromosomes 11 and 16 overlapped with Eae loci identified in other mouse crosses. By analyzing the backcross animals for lymphocyte phenotypes, the proportion of B and T cells in addition to the levels of CD4(+)CD8(-) and CD4(-)CD8(+) T cells and the CD4(+)/CD8(+) ratio in spleen were linked to different loci on chromosomes 1, 2, 3, 5, 6, 11, and 15. On chromosome 16, we found significant linkage to spleen cell proliferation. Several linkages overlapped with the quantitative trait loci for disease phenotypes. The identification of subphenotypes that are linked to the same loci as disease traits could be most useful in the search for candidate genes and biological pathways involved in the pathological process.

The effect of experimental infectious mastitis on leukocyte subpopulations and cytokine production in non-lactating ewes.

The interactions between leukocytes and cytokines during the acute response to intramammary infections in the dry mammary gland of sheep were studied. Dry ewes were experimentally infected in one udder half with either Staphylococcus aureus or Escherichia coli, or infused with saline as control. Udder secretion samples, blood samples and udder tissue samples were collected before and 4, 8 and 24 h after infections/infusions. Total and differential leukocyte counts were calculated in both blood and mammary secretions, and flow cytometry was used to detect the presence of CD4+, CD8+, WC1+, IL-2R+, CD18+ or L-selectin + lymphocytes, CD18+ or L-selectin + neutrophils, and CD14+ leukocytes. Moreover, the concentrations of interleukin-1 beta (IL-1 beta), interleukin-8 (IL-8) and granulocyte-macrophage colony stimulating factor (GM-CSF) in udder secretions were measured using ELISA, and RT-PCR was used to detect the presence of corresponding cytokine mRNA in udder tissue biopsies. The results suggest an association between the concentrations of IL-1 beta, IL-8 and the intensity of neutrophil infiltration of the infected gland. Immunologically relevant changes in proportions of lymphocyte subpopulations might also occur in the acute phase of the inflammatory reaction of the udder. Greater cellular and cytokine responses to E. coli infection may have contributed to the milder clinical picture and more rapid resolution of infection than that seen for S. aureus. Enhancing the production of pro-inflammatory cytokines may improve defence against bacterial mastitis.

Beta2-Adrenoceptor Density of Human Lymphocytes After Nitroprusside-Induced Hypotension

The present study was undertaken to assess the influence of nitroprusside-induced hypotension on beta2-adrenoceptor density. Twenty-four patients undergoing noseseptum corrections under general anesthesia were allocated randomly to a nitroprusside or control group. beta2-Receptor density on lymphocytes was measured by binding studies using (-)125 I-iodocyanopindolol. Lymphocyte subpopulations B, T, T (helper), Tsuppressor, and natural killer cells were determined simultaneously by flow cytometry. Five of 12 nitroprusside-treated patients developed significant intraoperative increases of epinephrine levels (+ 69% versus preoperatively) which were not seen in the remaining seven patients. In these five patients, beta2-receptor density of unfractionated lymphocytes was 26% lower (P < 0.05) on the first day after surgery compared with preoperative values. Since no changes in proportions of lymphocyte subpopulations were observed, these results are not caused by redistribution phenomena inducing a decrease of subsets with a high number of beta receptors. These findings suggest that beta2-adrenergic responsiveness might be diminished after nitroprusside treatment in some patients. (Anesth Analg 1995;81:1250-4)

Lymphocyte subpopulations in lymph and blood draining from the uterus and ovary in sheep

Lymphocyte subsets in utero-ovarian peripheral lymph and uterine and jugular venous blood were analysed with the aid of monoclonal antibodies, polyclonal antisera and flow microfluorometry. The proportion of various lymphocyte subpopulations, as determined by monoclonal antibodies (mAbs) and polyclonal antisera, was found to vary between utero-ovarian peripheral lymph and jugular and uterine venous blood. T cell levels were higher in utero-ovarian peripheral lymph (approx. 80% CD5 +, 50% CD4 + and 23% CD8 +) than peripheral blood (approx. 55% CD5 +, 18% CD4 + and 12% CD8 +). Conversely, in lymph, 10% of lymphocytes were B cells compared to 30% in blood. There were 20–30% MHC II + cells in utero-ovarian peripheral lymph and 40–50% in blood. The level of CD45R + cells in utero-ovarian peripheral lymph was low (2%) compared to peripheral blood (approx. 55% in pregnant and 25% in non-pregnant ewes). The proportion of lymphocyte subpopulations in lymph was similar for pregnant and non-pregnant ewes. However, some differences in levels in peripheral blood were evident between uterine and jugular venous blood and pregnant and non-pregnant ewes. CD4 + cells were higher in the uterine vein (14%) than in the jugular vein (11%) of pregnant ewes. The uterine and jugular veins in pregnant ewes contained approx. 50% MHC II + cells compared to 30% in non-pregnant ewes. Likewise, the proportion of CD45R + cells was higher in uterine and jugular venous blood of pregnant ewes (approx. 58%) compared to non-pregnant ewes (around 25%).

Symptomatic Treatment of Recurrent Malignant Pleural Effusions with Intrapleurally AdministeredCorynebacterium parvum

Intrapleural injection of Corynebacterium parvum (CBP) has been recently proposed as a useful symptomatic treatment of recurrent malignant effusions. Although the result is often a fibrotic thickening of the pleura, CBP is thought to stimulate the effector cells present in the effusion and, possibly, to activate the antitumor cytotoxic activity of the pleural fluid mononuclear cells. To test this hypothesis, we studied 7 patients with recurrent malignant pleural effusions caused by lung cancer and evaluated the cellular composition, the proportions of lymphocyte subpopulations, and the cytotoxic activity of mononuclear cells in the pleural fluid before and 7 days after injection of CBP in the pleural space. The CBP treatment induced a marked decrease in the rate of accumulation of pleural fluid (p less than 0.01) and in the concentration of immune effector cells in the pleural exudate (p less than 0.001). These changes were associated with a decrease in the percentages of pleural fluid monocytes and lymphocytes present (p less than 0.01, each comparison) and to a marked increase in the percentages of pleural fluid neutrophils (p less than 0.001). No significant changes in the proportions of T- and B-lymphocytes or in the proportions of helper/inducer and suppressor/cytotoxic T-cells or of natural killer cells were observed in the pleural exudate after CBP treatment (p greater than 0.2, each comparison). In addition, the cytotoxic activity of pleural fluid mononuclear cells was similar before and after CBP treatment (p greater than 0.2), and the levels of interferon, as a marker of immunoactivation of mononuclear cells, were not changed after treatment (p greater than 0.2).(ABSTRACT TRUNCATED AT 250 WORDS)

A preliminary report on bone transplantation. 1. An immunohistochemical study on the distribution and proportions of lymphocyte subsets in lymphoid organs of normal rats.

Although the rat is often used in experiments on bone transplantation, very few immunohistochemical studies on the distribution and proportions of lymphocyte subpopulations and subsets in rat lymphoid organs have been performed, in comparison with other animals. A preliminary immunohistochemical investigation using the immunofluorescence and avidin-biotin-peroxidase complex methods was therefore undertaken to clarify this aspect in various lymphoid organs taken from rats.The results obtained were as follows : 1. Ia-positive cells largely indicative of B cells were localized in the lymphoid follicles of lymph nodes, follicular areas of Peyer's patches and non-periarteriolar lymphatic sheath (PALS) areas of the spleen.2. T cells were densely distributed in the lymphoid pulp of lymph nodes, interfollicular areas of Peyer's patches and PALS areas of the spleen.3. Helper T-and asialo GM1-positive cells were localized in the lymphoid pulp of lymph nodes, interfollicular areas of Peyer's patches and spleen red pulp. The numbers of positive cells with these phenotypes were smaller than those of Ia-and pan T-positive cells.4. These results indicate that the distribution and proportions of lymphocyte subpopulations and subsets in rat lymphoid organs are generally similar to those of other animals such as the mouse.

Lymphocyte subpopulations of plateletapheresis products collected with the fenwal CS‐3000 cell separator

To determine whether any lymphocyte subset is preferentially harvested and transfused as a consequence of plateletapheresis with the Fenwal CS-3000 Blood Cell Separator, the proportions of lymphocyte subpopulations in platelet concentrates were compared to their proportions in the donors' peripheral venous blood immediately prior to platelet collection. There was no difference in the proportion of B cells (surface immunoglobulin positive), T cells (OKT3 positive), helper/inducer T cells (OKT4 positive), suppressor/cytotoxic T cells (OKT8 positive), and natural killer cells (Leu 7 positive) in the donors' peripheral venous blood and the plateletapheresis product. Thus, although previous studies have demonstrated the ability to separate lymphocyte subpopulations by density centrifugation and velocity sedimentation, plateletapheresis with the CS-3000 harvests the lymphocyte subpopulations studied in the same proportions in which they circulate in donors' peripheral venous blood.

IMMUNOLOGICAL EFFECTS OF SOLARIUM EXPOSURE

Normal volunteers underwent a standard course of treatment to acquire a suntan in a commercial solarium, and tests of immune function were carried out before, on completion, and 2 weeks after completion of radiation exposure. Compared with age and sex matched concurrent controls, the test subjects had reduced skin test responses to dinitrochlorobenzene (DNCB), slightly reduced blood lymphocyte numbers, and changes in the proportion of lymphocyte subpopulations. This included a relative increase in total (OKT3 +) T-cell numbers which was attributable to an increase in the OKT8 + suppressor/cytotoxic subset of T cells. OKT4 + helper T cells were reduced and there was a significant decrease in the OKT4/OKT8 ratio. Other changes included a significant increase in suppressor T-cell activity against IgG production in vitro and depression of natural killer cell activity. These changes were still present in some subjects 2 weeks after solarium exposure.