Leucoagglutinin induces differential proliferation of lymphocyte subsets

In this study we have established culture conditions that allow the preferential and rapid expansion of either T cell receptor (TCR)+/CD3+16- T lymphocytes or TCR-/CD3-16+ natural killer (NK) cells, or the non-selective outgrowth of both subsets. Optimal proliferation of lymphocytes was obtained using a combination of irradiated allogeneic peripheral blood lymphocytes (PBL) and irradiated Epstein Barr virus (EBV) transformed lymphoblastoid B cell lines (B-LCL). Addition of 1 microgram/ml leucoagglutinin to the culture medium induced a preferential outgrowth of TCR+/CD3+16- T lymphocytes. The proportion of TCR-/CD3-16+ NK cells was decreased to 5% or less, although still a 2000-fold multiplication of TCR-/CD3-16+ NK cells was obtained at day 13. Without leucoagglutinin a 1000-fold increase of about 70% pure TCR-/CD3-16+ NK cells was obtained at day 13. Intermediate concentrations of leucoagglutinin (0.1-0.3 micrograms/ml) resulted in a non-selective expansion of both NK cells and T cells. Irrespective whether leucoagglutinin was added or not, the number of TCR+/CD3+8+ lymphocytes increased more rapidly relative to the TCR+/CD3+4+ lymphocytes resulting in an increased TCR+/CD3+8+ population size. Also under limiting dilution conditions leucoagglutinin increased the frequency of proliferating cells. In contrast to the preferential outgrowth of TCR+/CD3+8+ lymphocytes in bulk cultures, approximately 80% of the clones generated was TCR+/CD3+4+, demonstrating a growth promoting effect of TCR+/CD3+4+ lymphocytes on TCR+/CD3+8+ lymphocytes in PBL bulk cultures.     

Early postnatal development of the immune system in piglets: the redistribution of T lymphocyte subsets

In this study, we have characterised postnatal changes in T lymphocyte subsets, especially γδ T lymphocytes, in blood, spleen and lymph nodes. Detection was carried out using two-colour flow cytometry and three-colour immunohistochemistry. During ontogeny, there was a significant increase in the total percentage of γδ T cells in the spleen and blood. In the lymph nodes, there were no age-dependent changes in the total percentage of γδ T cells, but the percentage of the γδTCR⁺CD8⁺ subpopulation significantly increased. The tissue distribution of γδTCR⁺CD8⁺ and γδTCR⁺CD8⁻ cells in the lymph nodes is random and not collocated with a particular area of the organ. Furthermore, postnatal development was characterised by an increasing frequency of CD8⁺CD3⁺CD4⁻γδTCR⁻, which was compensated by a decreasing proportion of CD4⁺ lymphocytes. Double positive CD4⁺CD8⁺ lymphocytes were rare during the first month of life and a significant age-dependent increase of these cells was found in all the compartments monitored.     

Lysis of herpes simplex virus-infected targets: II. Nature of the effector cells

Peripheral blood lymphocytes (PBL) from patients with herpes simplex virus (HSV)-1 recurrences in the cornea only (Group I) exhibited reduced lysis of HSV-1-infected targets compared to PBL from patients with oral-facial and corneal HSV recurrences (Group II). The cytotoxic lymphocytes appeared to belong to a subpopulation of natural killer (NK-HSV) cells. Monoclonal antibodies to human lymphocyte differentiation antigens were used to define the surface phenotype of the NK-HSV cells. Most of the NK-HSV activity was mediated by lymphocytes expressing the surface markers Leu-7⁺ (HNK-1), OKT3⁺ (pan T), OKM1⁺ (myeloid and NK), Leu-2^? (cytotoxic/ suppressor T cell), and Leu-8^? (regulatory T cell). In contrast, lysis of K562 cells (NK-K562) was mediated by lymphocytes bearing the surface phenotype Leu-7⁺, OKT3^?, OKM1⁺, Leu-2^+/?, and Leu-8^?. The low level of NK-HSV activity in PBL from Group I donors appeared to be due to active suppression by suppressor T lymphocytes. Depletion of Leu-2⁺ cells from PBL of Group I donors resulted in significant augmentation of NK-HSV activity. Similar treatment of PBL from Group II donors either had no effect or slightly diminished the NK-HSV activity.     

Effect of histamine and histamine antagonists on natural and antibody-dependent cellular cytotoxicity of human lymphocytes in vitro

The in vitro effect of histamine and its antagonists, cimetidine and clemastine fumarate, on natural killer (NK) and antibody-dependent cellular Cytotoxicity (ADCC) activities of human lymphocytes was investigated. The histamine 1 (H1) antagonist, clemastine fumarate, and the histamine 2 (H2) antagonist, cimetidine, but not histamine alone, inhibited the NK and ADCC activities of lymphocytes when added directly to the mixture of effector and target cells in a ⁵¹Cr-release assay. This inhibition was proportional to the concentration of drugs added and was observed at various effector to target ratios against several targets. H1 and H2 antagonists also inhibited NK activities of T cells as well as Percoll-separated, NK-enriched effector cells. The inhibition was significantly reversed by histamine. In target binding assays, clemastine fumarate and cimetidine also decreased the target binding capacity of effector lymphocytes. Further, PBL precultured with histamine (10^?3–10^?4M) for 24 hr showed a significant decrease in their NK and ADCC activities. In coculture experiments, PBL precultured with histamine suppressed the NK activity of normal autologous effector lymphocytes. PBL precultured with histamine showed an increased number of OKT8⁺ cells, as estimated using monoclonal antibodies. The suppression of Cytotoxicity was not due to either direct toxicity, steric hindrance, crowding, or cell death, but by functionally viable suppressor cells. An immunoregulatory role for histamine in NK and ADCC reactions is proposed.     

Participation of NK1.1+ T Cells in the Rejection of lpr αβT Cells When Bone Marrow Cells of Ipr Mice Are Transplanted into B6 Mice

When C57BL/6 (B6) mice were irradiated (9 Gy) and received bone marrow (BM) cells of B6-lpr/lpr mouse origin (i.e., lpr→B6), all mice died within 6 days. In the irradiated B6 mice, radioresistant CD3^? IL-2Rβ⁺ NK cells and IL-2Rβ CD3^int cells (i.e., CD3^int cells of extrathymic origin) remained, especially in the liver. There were two subsets, NK1.1⁺ and NK1.1^?, among the IL-2Rβ⁺ CD3^int cells. However, the NK1.1⁺ subset (i.e., NK1.1⁺ T cells) was much more radioresistant, and the majority of CD3^int cells belonged to this subset in irradiated mice. The expansion of lymphocytes from injected BM cells did not occur in the irradiated B6 mice. However, such expansion did take place in irradiated B6-lpr/lpr mice injected with both BM cells of B6-lpr/lpr and B6 origin. As a result, the mice subjected to BM cells survived. Irradiated B6 mice were treated in vivo with anti-NK1.1 mAb or anti-asialoGM₁ antibody to eliminate NK cells alone or both NK cells and NK1.1⁺ T cells. When irradiated B6 mice were pretreated with anti-NK1.1 mAb, the mice could survive. These results suggest that intact NK1.1⁺ T cells of extrathymic origin may recognize abnormal BM cells with the lpr gene and inhibit the expansion of lymphocytes, including abnormal double-negative CD4^?8^? cells, in B6-lpr/lpr mice. To inhibit the expansion of lymphocytes, mechanisms other than Fas ligand/Fas molecules on extrathymic T cells may be responsible.     

An epidemiological analysis of monitoring of the immune status of chernobyl nuclear accident liquidators for early detection of risk groups and diagnosis of cancer diseases. Communication 2. Dependence of the rate and changes in the immune status on radiation accident risk factors

It was demonstrated that malignant neoplasms (MNs) most frequently develop in the liquidators involved in the cleanup activities after the Chernobyl nuclear accident (ChNA) in 1986 (43.75%) and the liquidators involved in long-term activities, one-quarter of whom also participated in the cleanup in 1986. The specific features of the immune status (IS) depending on the period and year of the cleanup activities in the ChNA area were determined. In the cohort with a confirmed MN diagnosis, the observed deviations in the people who participated in these activities only in 1986 and on a permanent basis, including 1986, coincided in their pattern but differed in the magnitude of changes in immunological characteristics. Long-term participation during the extreme period and, correspondingly, higher exposure caused an increase in the contents of CD8⁺ T cells, CD16⁺ lymphocytes, and activated T lymphocytes, as well as decreases in the total immunoregulatory index, percentage of CD3-16/56⁺ (NK), and total IgE and a more pronounced deficiency in B lymphocytes. Differences between the groups of liquidators who participated in the cleanup activities in 1986 and 1987 were detected. The liquidators-1987 display the most pronounced deviations in the IS characteristics. Permanent presence in the ChNA area in 1986 and 1987 caused a similar effect but the magnitude of changes in the content of CD4⁺ T lymphocytes (↓), content of CD8⁺ T lymphocytes (↑), and immunoregulatory index (↓) was considerably higher in liquidators-1987. The permanent cleanup activities in Chernobyl in 1987 caused a deficiency in CD4⁺ T lymphocytes; more pronounced increase in the content of CD8⁺ T lymphocytes; decrease in CD4⁺/CD8⁺ index; change in the ratio of NK-T to NK cells; elevation in the counts of CD95⁺, HLA-DR⁺, and activated T lymphocytes; and decrease in the level of total IgE. Any increase in the expression of cell activation markers was undetectable in the liquidators-1986 involved in the cleanup activities on a long-term basis. The specific features of the IS changes depending on the dose of external γ-irradiation were determined. It was shown that the MN rate in liquidators increases with age relative to the number of examined people in each age cohort. The differences in the IS age-related dynamics in liquidators with and without MNs were detectable in stable contents of CD3⁺, CD4⁺, and CD8⁺ T lymphocytes; immunoregulatory index; and contents of CD95⁺ cells and serum IgA at ages of 40 to 70 years old with a subsequent decrease in these parameters and elevation in the content of CD8⁺ T lymphocytes with age in the absence of MNs; continuous increase in CD3-16/56⁺ (NK) cells in the presence of MNs; and decreases in these values after 70 years in the absence of MNs. In both groups of liquidators older than 70 years (with and without MNs), a deficiency in the T-cell component (CD3⁺ and CD4⁺ T lymphocytes and CD4⁺/CD8⁺ ratio) and an increase in the counts of CD8⁺ T lymphocytes are characteristic of the IS. A growing deficiency in CD4⁺ T lymphocytes during the monitoring on the background of increasing content of CD8⁺ T lymphocytes, which additionally contributes to the weakening of immune regulation due to progressing abnormalities in the ratio of regulatory T-lymphocyte subpopulations, can be regarded as one of the characteristics that suggest an adverse life expectancy prognosis for people with MNs.     

Immunological and nutritional factors in elderly people in low-level care and their association with mortality

Background

This study examines associations between markers of nutritional status and lymphocyte subsets and seeks to determine if lymphocyte profile is predictive of survival in elderly Australians residing in aged care facilities. Aged yet still ambulatory subjects (n?=?88, 73% female) living in low-level care and requiring minimal assistance were studied for 143 weeks. At baseline when participants were aged (mean?±?SD) 86.0?±?5.9 years, dietary intake was determined by 3-day weighed food record, body composition was assessed by dual energy X-ray absorptiometry (DXA) and a venous blood sample was taken.

Results

At baseline assessment, study participants were consuming nutrient-poor diets and most had symptoms of chronic disease. Although overweight, 40% exhibited sarcopenia. Markers of nutritional status did not relate closely to immune cell numbers (absolute or relative), which on average were within the normal range. Men had lower numbers of CD3⁺CD4⁺ cells (CD4⁺ T cells), a higher proportion of CD3^? CD16^± CD56^± (natural killer (NK) cells) and a higher ratio of NK: CD4⁺ T cells than women (all P?<?0.05). The main age-related changes evident were decreased T cells, particularly low CD4⁺ T cell counts, and increased numbers of CD19⁺ (B-cell) and NK cells. During the 143 week duration of follow-up, about one quarter of the study participants died, with death more likely in men than women (P?<?0.01). Poor survival was predicted by the presence of decreased numbers of CD4⁺ T cells (hazard ratio (HR) 0.919, P?<?0.01) and expanded numbers of NK cells (HR 1.085, P?<?0.05) in the blood, and therefore the presence of a high NK: CD4⁺ T cell ratio (HR 30.521, P?<?0.01).

Conclusions

The NK: CD4⁺ T cell ratio may potentially have clinical utility for predicting longevity in elderly populations. Further studies are needed in other elderly populations to confirm this finding.

     

Regulation of IL-21 signaling by suppressor of cytokine signaling-1 (SOCS1) in CD8(+) T lymphocytes

Mice lacking the gene for suppressor of cytokine signaling 1 (SOCS1) show defective homeostasis of T lymphocytes due to accumulation of CD8⁺ T cells, resulting at least partly from dysregulated IL-15 signaling. IL-15 alone does not stimulate proliferation of naïve CD8 T cells, but can synergize with IL-21 to induce proliferation, suggesting a potential role for IL-21 in the defective homeostasis of CD8⁺ T lymphocytes in SOCS1^−/− mice. Since IL-21 strongly induced SOCS1 mRNA in CD8⁺ T cells, we investigated whether SOCS1 regulates their response to IL-21. CD8⁺ T cells isolated from SOCS1-deficient mice proliferated vigorously in response to IL-21 + IL-15. In CD8⁺ T lymphocytes expressing transgenic TCR, IL-21 + IL-7 provided a stronger stimulus to naïve cells whereas IL-15 + IL-21 potently stimulated memory cells. Compared to truly naïve or memory cells, SOCS1^−/− H-Y TCR⁺ CD8⁺ T cells displayed CD44^loLy6C^hiCD122^intCD127^lo partial memory phenotype and exhibited stronger response to IL-15 + IL-21 than truly naïve cells. In SOCS1^−/− CD8⁺ T cells, IL-21 caused greater reduction in IL-15 threshold for activation in a dose-dependent manner. SOCS1 deficiency did not modulate IL-21Rα expression or sensitivity to IL-21, but delayed the loss of IL-21-induced phospho-STAT3 signal. These results show that SOCS1 is a critical regulator of IL-21 signaling in CD8⁺ T cells, and support the notion that sustained IL-21 signaling might also contribute to the aberrant T cell homeostasis in SOCS1-deficient mice.     

Relationship between CD107a expression and cytotoxic activity

NK cells play important roles in innate immunity against tumors and infections of the host. Studies show that CD107a (LAMP-1) may be a marker for degranulation of NK and activated CD8⁺ T cells. In our study, the relationship between the expression of CD107a, cytokine secretion and cytotoxic activity in CD56⁺ NK, CD8⁺ T cells and lymphocytes has been determined after various stimuli. Effector cells from PBMCs of healthy subjects were isolated and K562 cell line was used as target of cytotoxicity. IL-2 stimulation resulted in a significant increase of CD107a expression in CD56⁺ NK, CD8⁺ T cells and lymphocytes. Increased expression of CD107a after IL-2 stimulation of NK cells was parallel to the increase of cytotoxicity. Our results suggest that CD107a expression may be a sensitive marker for the cytotoxic activity determination.     

Increased tumor-infiltrating CD8+Foxp3+ T lymphocytes are associated with tumor progression in human gastric cancer

Background

CD8⁺Foxp3⁺ T lymphocytes have been detected in tumors. However, the distribution, phenotypic features, and regulation of these cells in gastric cancer remain unknown.

Methods

The levels of CD8⁺Foxp3⁺ T lymphocytes in the peripheral blood, tumor-draining lymph nodes, non-tumor tissues, and tumor tissues of patients with gastric cancer were detected by flow cytometry. Foxp3 induction in CD8⁺Foxp3^? T cells was investigated in vitro. The suppressive function of CD8⁺Foxp3⁺ T lymphocytes was analyzed by their effect on CD4⁺ T-cell proliferation and IFN-γ production. The percentages of CD8⁺Foxp3⁺ T lymphocytes were evaluated for the association with tumor stage.

Results

The frequency of CD8⁺Foxp3⁺ T lymphocytes in tumor tissues was significantly higher than that in non-tumor tissues, and similar results were also observed in tumor-draining lymph nodes compared with peripheral blood. Most intratumoral CD8⁺Foxp3⁺ T lymphocytes were activated effector cells (CD45RA^?CD27^?). TGF-β1 levels were positively correlated with the frequency of CD8⁺Foxp3⁺ T lymphocytes in tumor tissues, and in vitro TGF-β1 could induce the generation of CD8⁺Foxp3⁺ T lymphocytes in a dose-dependent manner. Furthermore, intratumoral CD8⁺Foxp3⁺ T lymphocytes suppressed the proliferation and IFN-γ production of CD4⁺ T cells. Finally, intratumoral CD8⁺Foxp3⁺ T lymphocytes were significantly increased with tumor progression in terms of tumor-node-metastasis (TNM) stage.

Conclusions

Our data have shown that increased intratumoral CD8⁺Foxp3⁺ T lymphocytes are associated with tumor stage and potentially influence CD4⁺ T-cell functions, which may provide insights for developing novel immunotherapy protocols against gastric cancer.     

Immune cell phenotype and functional defects in Netherton syndrome

Background

Netherton syndrome (NS) is a rare life-threatening syndrome caused by SPINK5 mutations leading to a skin barrier defect and a severe atopic diathesis. NS patients are prone to bacterial infections, but the understanding of the underlying immune deficiency is incomplete.

Results

We analyzed blood lymphocyte phenotypes and function in relation to clinical infections in 11 Finnish NS patients, aged 3 to 17?years, and healthy age-matched controls. The proportion of B cells (CD19⁺) and naïve B cells (CD27^?, IgD⁺) were high while memory B cells (CD27⁺) and switched memory B cells (CD27⁺IgM^?IgD^?), crucial for the secondary response to pathogens, was below or in the lowest quartile of the reference values in 8/11 (73%) and 9/11 (82%) patients, respectively. The proportion of activated non-differentiated B cells (CD21^low, CD38l^ow) was below or in the lowest quartile of the reference values in 10/11 (91%) patients. Despite normal T cell counts, the proportion of naïve CD4⁺ T cells was reduced significantly and the proportion of CD8⁺ T central memory significantly elevated. An increased proportion of CD57⁺ CD8⁺ T cells indicated increased differentiation potential of the T cells. The proportion of cytotoxic NK cells was elevated in NS patients in phenotypic analysis based on CD56DIM, CD16⁺ and CD27^? NK cells but in functional analysis, decreased expression of CD107a/b indicated impaired cytotoxicity.The T and NK cell phenotype seen in NS patients also significantly differed from that of age-matched atopic dermatitis (AD) patients, indicating a distinctive profile in NS. The frequency of skin infections correlated with the proportion of CD62L⁺ T cells, naïve CD4⁺ and CD27⁺ CD8⁺ T cells and with activated B cells. Clinically beneficial intravenous immunoglobulin therapy (IVIG) increased naïve T cells and terminal differentiated effector memory CD8⁺ cells and decreased the proportion of activated B cells and plasmablasts in three patients studied.

Conclusions

This study shows novel quantitative and functional aberrations in several lymphocyte subpopulations, which correlate with the frequency of infections in patients with Netherton syndrome. IVIG therapy normalized some dysbalancies and was clinically beneficial.

     

HLA-Dr-expressing CD8bright cells are only temporarily present in the circulation during subcutaneous recombinant interleukin-2 therapy in renal cell carcinoma patients

The effect of subcutaneous recombinant interleukin-2 (rIL-2) therapy on the activation status of peripheral blood lymphocytes (PBL) of 17 renal cell carcinoma patients was investigated in a longitudinal study. The expression of the activation markers HLA-Dr and CD25 on cytotoxic T cells, helper T cells, and natural killer (NK) cells, was analysed using two-colour flow cytometry of whole-blood samples. In addition, the ability of isolated PBL to proliferate in vitro in response to various stimuli was investigated. The absolute amounts of NK cells and HLA-DR-expressing NK cells increased continuously during the whole course of therapy. The absolute amounts of T cells and HLA-Dr-expressing T cells, however, showed an early increase only during the first 1 or 2 weeks of therapy, after which the absolute amounts of HLA-Dr-expressing T cells decreased. In particular, the absolute amount of HLA-Dr-expressing CD8bright⁺ T cells was significantly lowered in the second half of therapy. PBL collected on day 7 of therapy (post-cycle-1 PBL) showed, as compared to those collected prior to therapy (pretherapy PBL), a decreased proliferative response in vitro after stimulation with phytohaemagglutinin, concanavalin A, soluble CD3 mAb (WT32) or rIL-2. This decreased in vitro response of post-cycle-1 PBL was also reflected in a decrease in the percentage of CD8bright⁺ T cells expressing HLA-Dr in cultures with rIL-2 or CD3 mAb, in contrast to cultures of pretherapy PBL, which showed an increase of this percentage. We conclude that T cells are the predominantly stimulated subpopulation during the first 2 weeks of subcutaneous rIL-2 therapy. The significant decrease in the absolute amounts of HLA-Dr-expressing T cells in the peripheral blood during the second half of therapy may partly be explained by a decreased responsiveness to rIL-2, but a selective redistribution of HLA-Dr-expressing cells may also be involved.     

Changes in blood lymphocyte numbers with age in vivo and their association with the levels of cytokines/cytokine receptors

Background

Alterations in the number and composition of lymphocytes and their subsets in blood are considered a hallmark of immune system aging. However, it is unknown whether the rates of change of lymphocytes are stable or change with age, or whether the inter-individual variations of lymphocyte composition are stable over time or undergo different rates of change at different ages. Here, we report a longitudinal analysis of T- and B-cells and their subsets, and NK cells in the blood of 165 subjects aged from 24 to 90 years, with each subject assessed at baseline and an average of 5.6 years follow-up.

Results

The rates of change of T-(CD4⁺ and CD8⁺) and B-cells, and NK cells were relative stable throughout the adult life. A great degree of individual variations in numbers of lymphocytes and their subsets and in the rates of their changes with age was observed. Among them, CD4⁺ T cells exhibited the highest degree of individual variation followed by NK cells, CD8⁺ T cells, and B cells. Different types of lymphocytes had distinct trends in their rates of change which did not appear to be influenced by CMV infection. Finally, the rates of CD4⁺, CD8⁺ T cells, naive CD4⁺ and naïve CD8⁺ T cells were closely positively correlated.

Conclusion

Our findings provide evidence that the age-associated changes in circulating lymphocytes were at relative stable rates in vivo in a highly individualized manner and the levels of selected cytokines/cytokine receptors in serum might influence these age-associated changes of lymphocytes in circulation.

     

Elevated level of peripheral CD8+CD28− T lymphocytes are an independent predictor of progression-free survival in patients with metastatic breast cancer during the course of chemotherapy

Purpose

Suppression of cellular immunity resulting from tumorigenesis and/or therapy might promote cancer cells’ growth, progression and invasion. Here, we explored whether T lymphocyte subtypes from peripheral blood of metastatic breast cancer (MBC) female patients could be used as alternative surrogate markers for cancer progress. Additionally, plasma levels of interleukin (IL)-2, IL-4, IL-6, IL-10, IFN-γ, and transforming growth factor-β1 were quantitated from MBC and healthy volunteers.

Experimental design

This study included 89 female MBC patients during the post-salvage chemotherapy follow-up and 50 age- and sex-matched healthy volunteers as control. The percentages of T lymphocyte subpopulations from peripheral blood and plasma levels of cytokines were measured.

Results

Both CD8⁺CD28^? and CD4⁺CD25⁺ were elevated in MBC patients compared to the control cohort (P < 0.05). In contrast, CD3⁺ and CD8⁺CD28⁺cells were significantly lower in MBC patients (P < 0.0001, P = 0.045, respectively). MBC patients had elevated levels of immunosuppressive cytokines IL-6 and IL-10. Patients with elevated CD8⁺CD28^? and CD4⁺CD25⁺ cells showed increased levels of IL-6, and only patients with elevated CD8⁺CD28^? had decreased interferon-γ. Univariate analysis indicated increased CD3⁺CD4⁺ or CD8⁺CD28⁺correlated with prolonged progression-free survival (PFS), while elevated CD8⁺CD28^?associated with shorten PFS. The percent of CD8⁺CD28^? T lymphocytes is an independent predictor for PFS through multivariate analysis.

Conclusions

This study suggests that progressive elevated levels of CD8⁺CD28^? suppressor T lymphocytes represent a novel independent predictor of PFS during post-chemotherapy follow-up.     

Blood,transmitters and neuropeptides

Abstract

Total T lymphocytes and their subsets CD3⁺8⁺, CD3M⁺, CD4⁺45R⁺, respectively TCRab⁺ and TCRgd⁺ cells as well as CD19⁺B cells exhibited significantly circadian variations in venous blood from healthy men with peak times between 23.00 to 24.00 h, respectively around 21.00 h. Natural killer (NK) cells peaked between 11.00 and 12.00 h insignificantly. A similar inverse relationship was found between T (B) cells and plasma levels of ACTH, cortisol and human growth hormone, whereas NK cells and prolactin levels may be related in another way.     

Distribution of Several Activating and Inhibitory Receptors on CD3<Superscript>−</Superscript>CD16<Superscript>+</Superscript> NK Cells and Their Correlation with NK Cell Function in Healthy Individuals

The aim of this study was to estimate the distribution and density of a representative set of activating and inhibitory receptors on gated natural killer (NK) cells, as well as on their bright and dim subsets, and to correlate the receptor expression with NK cell activity for healthy individuals on CD3⁻CD16⁺ NK cells. We show that in 43 healthy controls NK cell activity against K562 target cells was 37.34% (E:T, 80:1) by standard chromium release assay. The expression of receptors on NK cells and their subsets was analyzed by flow cytometry. The cytotoxic CD3⁻CD16^bright NK subset constituted 78.97%, while the regulatory CD3⁻CD16^dim NK subset constituted 21.03% of NK cells. We show the distribution of NKG2D, CD161, CD158a, and CD158b receptors on CD3⁻CD16⁺ NK cells in peripheral blood lymphocytes (PBLs), on gated NK cells, and on the CD3⁻CD16^bright and CD3⁻CD16^dim subsets. Contrary to CD158a and CD158b killer immunoglobulin-like receptors (KIRs), there is a significant positive correlation of NKG2D and CD161 expression with NK cytotoxicity. We show the kinetics of change in CD3⁻CD16⁺NK/K562 conjugate composition, together with the stronger target binding capacity of CD16^bright NK cells. Furthermore, we show that after coculture of PBLs with K562 the expression of CD107a, a degranulation marker, on CD3⁻CD16⁺NK cells and subsets is time dependent and significantly higher on the cytotoxic CD3⁻CD16^bright NK subset. The novel data obtained regarding expression of NK cell activating and inhibitory receptors for healthy individuals may aid in detecting changes that are associated with various diseases.     

Enhancement of Astragalus polysaccharide on the immune responses in pigs inoculated with foot-and-mouth disease virus vaccine

The effects of Astragalus polysaccharides (APS) on the immune response in pigs immunized with foot-and-mouth disease virus (FMDV) vaccine were investigated. Fifteen pigs were randomly divided into five groups. Four groups were vaccinated with a FMDV inactivated vaccine. Pigs in three experimental groups were administered varying doses of APS (APS1, 5 mg/kg; APS2, 10 mg/kg; APS3, 20 mg/kg). The influence of APS on the number of CD3⁺CD4⁻CD8⁺ cytotoxic T cells, CD3⁺CD4⁺CD8⁺ T helper memory cells, and CD3⁻CD4⁻CD8⁺ natural killer cells among peripheral blood lymphocytes (PBL) in the three APS groups were significant compared to the vaccine group. In vitro stimulation of PBL by Con A and LPS in APS groups induced a stronger proliferative response at 2 and 6 weeks post-inoculation (PI). APS markedly increased the titer of FMDV-specific antibody in a dose-dependent manner, and up-regulated mRNA expression of IFN-γ and IL-6. APS could potentially be used as an immunomodulator for a FMDV vaccine and provide better protection against FMDV.     

Decrease in pool of T lymphocytes with surface phenotypes of effector and central memory cells under Influence of TCR transgenic β-chain expression

Peripheral T lymphocytes can be subdivided into naive and antigen-experienced T cells. The latter, in turn, are represented by effector and central memory cells that are identified by different profiles of activation markers expression, such as CD44 and CD62L in mice. These markers determine different traffic of T lymphocytes in the organism, but hardly reproduce real antigenic experience of a T lymphocyte. Mechanisms of homeostasis maintenance of T lymphocytes with different activation phenotypes remain largely unknown. To investigate impact of T cell receptor (TCR) transgenic chains on formation of T lymphocytes, their peripheral survival and activation surface phenotypes, we have generated the transgenic mouse strain expressing transgenic β-chain of TCR 1D1 (belonging to the Vβ6 family) on the genetic background B10.D2(R101). Intrathymic development of T cells in these transgenic mice is not impaired. The repertoire of peripheral T lymphocytes in these mice contains 70–80% of T cells expressing transgenic β-chain and 20–30% of T cells expressing endogenous β-chains. The ratio of peripheral CD4⁺CD8^? and CD4^?CD8⁺ T lymphocytes remained unchanged in the transgenic animals, but the percent of T lymphocytes with the “naive” phenotype CD44^?CD62L⁺ was significantly increased, whereas the levels of effector memory CD44⁺CD62L^? and central memory CD44⁺CD62L⁺ T lymphocytes were markedly decreased in both subpopulations. On the contrary, T lymphocytes expressing endogenous β-chains had surface phenotype of activated T cells CD44⁺. Thus, for the first time we have shown that the pool of T lymphocytes with different activation phenotypes depends on the structure of T cell receptors.