Interaction of B and T lymphocyte subsets with high endothelial venules in the rat: binding in vitro does not reflect homing in vivo

Lymphocytes continuously migrate through the body, and their efficient extravasation from the blood via high endothelial venules (HEV) is essential for initiating an appropriate immune response. Most investigations have focused on the lymphocyte/HEV interaction in vitro. However, to what extent such systems reflect the situation in vivo is not known. It is also unclear whether lymphocyte subsets immigrate into the HEV in proportion to their presence in the blood, and whether import capacity is limited by the HEV. When rat mesenteric lymph node lymphocytes were incubated in vitro on cryostat sections, the well-known preferential binding of B lymphocytes to HEV of Peyer's patches (PP) and T cells to HEV of axillary lymph nodes (axLN) was observed (axLN vs. PP: B lymphocytes 21.2 ± 5.0% vs. 40.6 ± 11.0%, T lymphocytes 84.6 ± 6.3% vs. 56.5 ± 12.9%). However, when labeled mesenteric lymph node lymphocytes were injected and their location within the HEV was analyzed 15 min later, no preferential interaction was seen. After injection of labeled thoracic duct lymphocytes, the percentage of labeled cells among B and T lymphocytes in the blood was significantly different (4.4 ± 0.9% vs. 8.9 ± 3.6%), whereas that in HEV of axLN (19.0 ± 6.4% vs. 16.6 ± 6.0%) and PP (30.6 ± 6.1% vs. 33.9 ± 4.4%) was comparable. Although the number of injected lymphocytes was similar in magnitude to the total blood lymphocyte pool, after injection there was no increase in lymphocyte numbers in the HEV. Thus, the adhesion assay in vitro does not completely reflect immigration into HEV in vivo. In addition, our data suggest that both the availability of lymphocyte subsets in small venules and the immigration rate into HEV are actively regulated in vivo.     

Thymidine in the micromolar range promotes rejoining of UVC-induced DNA strand breaks and prevents azidothymidine from inhibiting the rejoining in quiescent human lymphocytes

The effect and inter-individual variation in the effect of exogenously added deoxynucleosides (2×10⁻⁶ M) on rejoining of UVC-induced DNA strand breaks was examined in quiescent human lymphocytes from 25 healthy persons. Thymidine at concentrations below 2×10⁻⁶ M, effectively and with statistically extreme significance, increased rejoining of UVC-induced DNA strand breaks in the lymphocytes of every one of the 25 persons tested (p<0.0001, Wilcoxon's signed ranks test). The mean stimulation after 20 h of postirradiation repair was 48% (range 18–78%) with an inter-individual variation of 30% (coefficient of variation, CV). Deoxyguanosine stimulated rejoining in 16, but inhibited in three of 19 test persons (mean stimulation 28%, range −31 to 71%). The stimulating effect of deoxyguanosine was also extremely significant (p<0.0004). Deoxycytidine and deoxyadenosine stimulated rejoining in some persons and inhibited it in others, and without statistical significance (p values above 0.5). The stimulating effect of thymidine was significantly inhibited by deoxycytidine (p<0.05, n=12) whereas deoxyguanosine neither promoted or inhibited the stimulation by thymidine (p=1, n=12). Rejoining of DNA strand breaks induced by methyl methanesulfonate did not appear significantly stimulated or inhibited by any of the four deoxynucleosides. Finally, the inhibiting effect of azidothymidine (AZT) on rejoining of UVC-induced DNA strand breaks was nullified by the addition of thymidine. In three donors examined, 10⁻⁴ M AZT inhibited the rejoining by about 40–50%. The presence of less than 10⁻⁵ M thymidine reduced the level of UVC-induced DNA strand breaks to below the level in control lymphocytes allowed to repair without AZT. These results indicate that among the four deoxynucleoside triphosphates, dTTP has a crucial role on the repair of UVC-induced DNA damage in quiescent lymphocytes. The results also indicate that an expansion of the dTTP pool may counteract the inhibiting effect of AZT on DNA repair in quiescent lymphocytes.     

REACTIVITY OF LYMPHOCYTE SUBPOPULATIONS IN HUMAN MIXED LYMPHOCYTE CULTURE

Loss of antigenicity in the mixed lymphocyte culture (MLC) reaction of lymphocytes precultured at 22°C for 7–10 days was accompanied by a decrease in bone-marrow-derived lymphocytes (B cells) from 22 ± 1% to 13 ± 1%, and an increase in thymus-derived lymphocytes (T cells) from 65 ± 2% to 83 ± 1% (P < 0.001). Depletion of B cells from a fresh lymphocyte suspension by either antihuman immunoglobulin-coated column fractionation or by sheep red blood cell (SRBC) rosette formation resulted in a significant reduction of the cell's ability to stimulate in MLC (P < 0.001). Coating of lymphocytes with rabbit antihuman brain serum abrogated their ability to respond but not the ability to stimulate in MLC.     

Induction of DNA-strand breaks in human peripheral blood lymphocytes and A549 lung cells by sodium dichromate: association with 8-oxo-2-deoxyguanosine formation and inter-individual variability.

Hexavalent chromium [Cr(VI)] is a genotoxic carcinogen for which inhalation is a major potential route of exposure in occupational settings. In the present study, the ability of sodium dichromate to cause DNA strand breaks in three populations of cells, human whole blood cells, isolated human peripheral blood lymphocytes and cultured A549 lung epithelial cells, was investigated. Treatment with non-cytotoxic concentrations of sodium dichromate (for 1 h) resulted in a concentration-dependent increase in the number of DNA strand breaks as measured by the Comet assay. The lowest concentrations of sodium dichromate that resulted in a statistically significant (P < 0.01) increase in the number of DNA strand breaks were 500, 50 and 10 microM, respectively, in these cells. The use of formamidopyrimidine glycosylase increased the sensitivity of detection of strand breaks in A549 cells 10-fold, suggesting a role for DNA base oxidation in the mechanism of dichromate-induced DNA strand breaks. In support of this hypothesis, immunocytochemistry indicated an elevation of 8-oxodeoxyguanosine in A549 cells treated with 10 and 500 microM sodium dichromate for 1 h. We also demonstrated 2.11- and 2.5-fold ranges in the level of control and dichromate (500 microM)-induced DNA strand breaks, respectively, in cells of whole blood within a group of healthy volunteers (n = 26). A statistically significant (P < 0.001) positive Pearson's correlation (r = 0.606) was found between control and treated levels of DNA strand breaks, suggesting that factors responsible for relatively low levels of DNA strand breaks in untreated PBL may also offer protection against the formation of dichromate-induced DNA strand breaks.     

The effect of 4-week training period on plasma neuropeptide Y,leptin and ghrelin responses in male rowers

The aim was to investigate the effect of high-volume low intensity resistance training protocol combined with endurance training on plasma neuropeptide Y (NPY) concentration in rowers. Additionally, leptin and ghrelin, as markers for body energy balance concentrations, were monitored. 12 highly trained national and international level male rowers participated in this study. The participants were tested three times—after reference week (T1), after 2 weeks of high-volume training (T2) and after a recovery week (T3) for aerobic performance, energy intake and expenditure, and blood biochemical parameters. The submaximal rowing performance decreased significantly (P = 0.019) at T2. Fasting leptin decreased significantly (from 2.05 ± 0.88 to 1.28 ± 0.53 ng/mL; P = 0.009) at T2 and increased significantly (from 1.28 ± 0.53 to 1.79 ± 0.79 ng/mL; P = 0.002) at T3. Fasting ghrelin decreased significantly (from 980 ± 300.2 to 873.35 ± 198.6 pg/mL; P = 0.036) at T3 compared to T2, while no changes were found in fasting NPY. Significant decreases in exercise-induced leptin were observed at T2 (from 1.13 ± 0.5 to 1.08 ± 0.5 ng/mL; P = 0.012), PRE and POST test leptin values at T2 were significantly decreased compared to T1(1.40 ± 0.9 to 1.13 ± 0.5 and 1.44 ± 0.8 to 1.08 ± 0.5, respectively). Acute exercise-induced increases in NPY were found at T2 (from 128.1 ± 23.2 to 155.1 ± 28.9 pmol/L; P = 0.002) and at T3 (from 131.3 ± 20.5 to 159.7 ± 32.8 pmol/L, P = 0.004). In conclusion, the combination of high-volume training protocol and energy imbalance induces significant post-exercise changes in NPY, leptin, and ghrelin concentrations and decreases fasting leptin.     

B and T lymphocyte subsets enter peripheral lymph nodes and Peyer's patches without preference in vivo: no correlation occurs between their localization in different types of high endothelial venules and the expression of CD44, VLA-4, LFA-1, ICAM-1, CD2 or L-selectin

Many lymphocytes enter tissues such as peripheral lymph nodes and Peyer's patches through high endothelial venules (HEV). It is known that HEV differ in the expression of adhesion molecules as lymphocyte subsets do. Through the interaction of these molecules B and T lymphocyte subsets are thought to be preferentially directed into lymphoid organs. However, it is unclear which role these mechanisms play in vivo, since there are no studies demonstrating that blood lymphocyte subsets preferentially interact with different types of HEV in vivo. Therefore, in the present study the frequency of B, T, CD4⁺ and CD8⁺ lymphocytes in the wall of the HEV of rat peripheral lymph nodes and Peyer's patches was analyzed by immunohistology. In addition, the expression of CD44, VLA-4, LFA-1, ICAM-1, CD2 and L-selectin on B and T lymphocyte subsets of the blood was determined by flow cytometry. Although B and T lymphocytes showed significantly different levels of expression for each adhesion molecule investigated, the relation of B and T lymphocytes within the HEV of peripheral lymph nodes and Peyer's patches was strikingly comparable (38.0 ± 5.2% vs. 40.6 ± 5.7% and 62.0 ± 5.2% vs. 59.4 ± 5.7%, respectively). The same was true for CD4⁺ and CD8⁺ cells. Thus, although HEV and the blood lymphocyte subsets differ markedly in their expression pattern of adhesion molecules, the existing levels are sufficient to mediate comparable entrance of B and T lymphocyte subsets into both types of HEV.     

Breast milk cell supernatants from atopic donors stimulate cord blood IgE secretion in vitro

Breast milk cell culture supernatants from atopic mothers (nineteen) were compared by ELISA with normal breast-feeding controls (twenty-one) for regulation of cord blood lymphocyte IgA and IgE secretion in vitro. A minority of atopic (five out of nineteen) and normal (three out of twenty-one) cell supernatants stimulated cord blood lymphocyte IgA release to the same extent. The others were inactive. Stimulation was not related to breast milk cells donor atopic history or cord blood lymphocyte atopic heredity. In contrast, 70% of atopic milk cell supernatants stimulated cord blood lymphocyte cultures to form IgE (x± s.d. = 2070 ± 2240 pg/culture) while stimulatory supernatants (24%) from normal donors resulted in less lymphocyte IgE release (x ± s.d. = 680 ± 490 pg/culture) (P< 0.001). These differences did not correlate with breast milk cell supernatant IgE concentrations, cord blood donor serum IgE levels or atopic heredity.     

Sensitivity of peripheral blood lymphocytes of pilots and astronauts to γ-radiation: Induction of double-stranded DNA breaks

The levels of DNA breaks before and after in vitro irradiation (1 Gy) of lymphocytes from 17 donors, 41 pilots, and 8 astronauts were studied by comet assay. Seventeen donors, 41 pilots, and 8 astronauts were examined. The flights augmented individual differences in the levels of DNA breaks in blood lymphocytes and in the severity of injuries inflicted by radiation exposure to lymphocyte DNA. Dispersions in the distribution of the initial levels of DNA breaks in pilots and astronauts differed significantly from the control according to Fisher’s F test. The dispersion of distribution of the levels of double-stranded DNA breaks after in vitro irradiation in the group of pilots also differed significantly from the control distribution. These results necessitate evaluation of individual sensitivity to the mission conditions during medical selection. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 10, pp. 404–407, October, 2007     

Lymphocyte subsets in distinct lung compartments show a different ability to produce interferon-gamma (IFN-γ) during a pulmonary immune response

Lymphocytes play an important immunoregulatory role in pulmonary immune responses. By releasing cytokines they can control the cell–cell communication of other participating cells. Although it is well established that the lung lymphocytes, localized in distinct compartments, differ in their subset composition, little is known about cytokine production in these compartments during immune responses. Lewis rats were immunized by intravenous administration of sheep erythrocytes on day 0 and day 7 and challenged intratracheally with sheep erythrocytes on day 10. Four days after intratracheal (i.t.) challenge the composition of lymphocyte subsets (CD2⁺, CD4⁺, CD8⁺, B cells, natural killer (NK) cells) in the spleen, blood, lung perfusate, lung tissue and bronchoalveolar lavage fluid (BALF) was characterized, and intracellular IFN-γ was detected in these subsets by flow cytometry. Comparing control and immunized animals, no changes were found in lymphocyte numbers, subsets or the percentage of IFN-γ-producing lymphocytes in the spleen, blood and lung perfusate. In lung tissue and BALF, however, the absolute number of all lymphocyte subsets and the percentage of IFN-γ-producing lymphocytes were increased. When the lymphocyte subsets were analysed an increased percentage of IFN-γ-producing T cells was found in lung tissue (4.5 ± 0.6% versus 12.8 ± 1.1%) and in BALF (7.8 ± 1.4% versus 14.8 ± 1.9%) of immunized animals opposed to controls, this increase being seen in both CD4⁺ and CD8⁺ cells. Thus, there is an accumulation of T cells with an increased potential to produce IFN-γ in the lung interstitium and the bronchoalveolar space during pulmonary immune responses.     

Analysis of DNA single-strand breaks in human venous blood: A technique which does not require isolation of white blood cells

For DNA strand break analysis in human white blood cells, usually metrizoate-Ficoll centrifugation is used to isolate mononuclear cells. This procedure is time-consuming and requires at least 20 ml of blood per sample. Therefore, we developed a technique which does not require isolation of white blood cells prior to DNA strand break analysis by alkaline elution (direct method). The sensitivity of this new technique was compared to that of the standard method, which includes isolation of mononuclear blood cells. A statistically significant increase in sensitivity was observed using the direct method. After in vitro gamma-irradiation of venous blood, an increase in the elusion rate of 7.7 × 10⁻³ hr⁻¹/Gy was detected if mononuclear blood cells were isolated compared to 10.5 × 10⁻³ hr⁻¹/Gy with the new technique (P < 0.05). Incubation of venous blood with ethylene oxide for 1 hr caused an increase in the elution rate of 5.8 × 10⁻³ hr⁻¹/mM ethylene oxide for the standard and 12×10⁻³h⁻¹/mM for the direct method (P < 0.05). DNA single-strand breaks were detected in blood cells of 10 persons without any apparent genotoxic exposure. A mean normalized elution rate of 1.30 ± 0.38 (95% confidence interval) was detected in isolated mononuclear blood cells, and a similar mean normalized elution rate of 1.41 ± 0.50 was obtained using the direct method. The difference was not statistically significant. Five patients treated with a combination chemotherapy consisting of cyclophosphamide (750 mg/m² i.v.), doxorubicin (50 mg/m² i.v.), vincristine (1.4 mg/m² i.v.), and prednisolone (100 mg/m² p.o.) for non-Hodgkin's disease were analyzed for DNA single-strand breaks before and 16–18 hr after the application of chemotherapy. Increases in mean elution rate of 68% and 116% were detected using the standard and the direct methods, respectively. For the direct method, only 3 ml of venous blood were sufficient for analysis of one sample, compared to 25 ml needed if mononuclear cells were isolated, and about 4 hr of work per assay can be saved. Environ. Mol. Mutagen. 29:58–62, 1997 © 1997 Wiley-Liss, Inc.     

Effects of three consecutive days exercise on lymphocyte DNA damage in young men

Intense exercise affects the immune system. This study examines effects of three consecutive days of 1 h high-intensity exercise on lymphocyte counts, oxidative DNA damage, and apoptosis in young untrained (n = 8, 23.8 ± 3.2 years; UT) and endurance-trained (n = 8, 21.1 ± 3.7 years; TR) subjects. The subjects performed cycle ergometer exercise at 75% _boxclose_2 \dot{V}{\text{O}}_{2\max } 1 h daily for three consecutive days (exercise session). Blood samples were collected before exercise on the first day of the exercise session (day 1, D1) and at 24 h after the session (day 4, D4). Total lymphocyte counts, a lymphocyte oxidative DNA damage index using Comet assay with human 8-oxoguanine DNA glycosylase, oxidative stress markers, and apoptosis markers were measured. Lymphocyte counts at D1 in TR were significantly lower than in UT. Lymphocyte counts in TR changed little at D4 (from 1,988 ± 475 to 1,854 ± 363 cell/μl), but the lymphocyte counts in UT decreased significantly at D4 (from 2,583 ± 564 to 1,911 ± 528 cell/μl, P < 0.05). Lymphocyte oxidative DNA damage increased concomitantly with exercise sessions in both the groups (UT, from 31.3 ± 17.5 to 48.9 ± 15.7%; TR, from 21.9 ± 5.2 to 62.1 ± 12.5%, P < 0.05). Although no change was found in apoptosis markers over time, Annexin-V⁺ cells decreased in TR (effect size D = 0.8 is large). Three consecutive days of 1 h exercise decreased lymphocyte counts with increased lymphocyte oxidative DNA damage in UT. Lymphocyte counts remained unchanged irrespective of increased oxidative DNA damage in TR. Decreased lymphocyte apoptosis might prevent the decrease of lymphocytes in TR.     

Analysis of B-lymphocyte differentiation in patients infected with hepatitis C virus

To clarify whether some of the functions of B lymphocytes could be affected during hepatitis C virus (HCV) infection, phenotypic characteristics of B lymphocytes from HCV-infected patients and their capacity to differentiate into immunoglobulins (Ig)-secreting cells were studied. B lymphocytes differentiation was investigated for patients untreated and non-responders (n = 9), treated and non-responders (n = 6), responders (n = 6), long-term responders (n = 9) to therapy and seronegative controls (n = 14) following in vitro stimulation with S. aureus strain Cowan I mitogen. HCV sequences in purified B lymphocytes were detected by RT-PCR. It was found that HCV-patients harbor a similar mean percentage of B cells and a normal level of naïve B cells (% IgM⁺/IgD⁺ cells = 79.7 ± 15.4 for untreated non-responders, 57.1 ± 22.9 for treated non-responders, 44.3 ± 29.1 for responders, 75.7 ± 16 for long-term responders) as compared with controls. It was also found that peripheral blood mononuclear cells (PBMCs) of patients or controls produced similar amounts of IgG, A, and M in vitro. A total of 57% of untreated non-responders versus 17% of treated non-responders were able to produce HCV-specific antibodies. Interestingly, B lymphocytes from PBMCs able to secrete anti-HCV antibodies contained HCV positive strand RNA, although no systematic detection of the negative strand was found. These data suggest that signaling through the B cell receptor (BCR) in B lymphocytes of HCV-infected patients appears normal whatever their response to therapy. The capacity to secrete HCV-specific IgG seemed to be linked to the presence of positive strand RNA rather than virus replication. J. Med. Virol. 72:566–574, 2004. © 2004 Wiley-Liss, Inc.     

Use of Lymphocyte Platelet Binding Assay for Detecting a Preimplantation Factor: A Quantitative Assay

PROBLEM: To evaluate the ability of the lymphocyte/platelet binding assay to identify a preimplantation factor (PIF). METHOD: Percentages of binding of lymphocytes by platelets in the presence of sera from 30 known pregnant and 30 nonpregnant individuals were compared using a novel lymphocyte/platelet binding assay. The assay is performed using a combination of a heat inactivated sera with donor O+ lymphocytes, activated complement and an antibody against CD₂(T11, Ortho Pharmaceuticals). RESULTS: In nonpregnant females (23.6 ± 6.5%) and males (17.7 ± 4.7%) the percentage of lymphocytes bound by platelets was significantly different from pregnant women (56.1 ± 15.9%) (P < 0.0001). Serial sampling of blood in five women undergoing IVF/ET who had normal pregnancies showed the detection of PIF by 4 days after transfer. The lymphocyte/platelet binding assay was not influenced by hCG, progesterone and estradiol. The interassay and intraassay variabilities were <3%. CONCLUSIONS: The lymphocyte/platelet binding assay is a simple, reproducible, specific and cost efficient assay for measurement of PIF. Application of this assay will provide investigative and diagnostic tools for identifying and monitoring early pregnancy events.     

Lymphocyte glucocorticoid receptors in asthmatic and control subjects

Glucocorticoid hormones, which are widely used in the treatment of asthma, have been shown to potentiate physiological and biochemical beta-adrenergic responsiveness in asthmatics. These effects are presumably mediated through glucocorticoid receptors. In order to better understand glucocorticoid pharmacology in asthmatics, we assayed glucocorticoid receptors by directly binding a radioactively labelled glucocorticoid hormone, dexamethasone, to intact lymphocytes prepared from the peripheral blood of asthmatics and control subjects. Binding studies were performed with dexamethasone at 100 nm and 5 nm concentrations. At 100 nm dexamethasone, the mean number of lymphocyte glucocorticoid receptors (per cell) in control subjects (7191 ± 385. n= 9) was not significantly different from that in asthmatic subjects (7772 ± 437, n = 9). At 5 nm dexamethasone, the mean number of glucocorticoid receptors in control subjects (1177 ± 194, n= 5) was not significantly different from that in asthmatic subjects (1215 ± 108. n= 8). At 100 nm dexamethasone, males had significantly more receptors (7939 ± 360. n= 11) than females (6764 ± 72, n= 7). Our results suggest that the number of lymphocyte glucocorticoid receptors and the apparent affinity of dexamethasone for receptors are not related to the presence or severity of asthma; however, a significant sex effect exists which should be corrected for in future studies of lymphocyte glucocorticoid receptors.     

Insulin-like growth factor-1 attenuates glucocorticoid suppression of pig lymphocyte function

This study evaluated the effects of dexamethasone and insulin-like growth factor-1 on mitogen-induced lymphocyte immune-associated activities including metabolic reduction of the tetrazolium salt and immunoglobulin (Ig) production. Peripheral blood lymphocytes were isolated from blood samples obtained from three 6-week-old male pigs and plated in triplicate for treatment and dose (n=9 wells/treatment/dose). Cells were stimulated with specific doses and combinations of concanavalin A (ConA), pokeweed mitogen (PWM), DEX and/or IGF-1. Both Con A and PWM induced dose-dependent increases (P<0.05) in lymphocyte metabolism and IgM production. Lymphocyte metabolism and IgM production induced by submaximal concentrations of ConA and PWM were dose-dependently suppressed (P<0.05) by DEX. Treatment with IGF-1 attenuated (P<0.5) the suppressive effects of DEX on ConA- but not PWM-induced lymphocyte metabolism. The addition of IGF-1 reduced (P<0.05) DEX suppression of ConA- and PWM-induced IgM production. These results demonstrate that IGF-1 can differentially reduce the suppressive effects of DEX on lymphocytes dependent on mitogen type.     

Prostaglandin E2 suppresses phytohemagglutin-induced immune responses of normal human monoculear cells by decreasing intracellular glutathione generation,but not due to increased DNA strand breaks or apoptosis

Prostaglandin E₂ (PGE₂) at concentrations more than 1×10^–8 M markedly suppressed the cell proliferation and release of soluble molecules of interleukin-2 receptor (sIL-2R), CD4 (sCD4) and CD8 (sCD8) from phytohemagglutinin (PHA)-stimulated normal human mononuclear cells (MNC) in a dose-related manner. To further elucidate the subcellular mechanism of the inhibitory effect of PGE₂ on PHA-stimulated MNC, intracellular concentration of glutathione (GSH) in PHA-stimulated MNC was sequentially measured from day 1 to day 3 by enzymic method. Furthermore, the effect of PGE₂ on nuclear DNA including DNA strand breaks in alkali treatment and DNA fragmentation (apoptosis) of PHA-stimulated MNC were also measured. We found intracellular GSH levels were significantly decreased in the early stage of lymphocyte activation (day 1), but no evidence of increased DNA stand breaks or apoptotic process appeared in 3-day culture. In addition, butathione sulfoximine (a specific GSH inhibitor) and dibutyryl cyclic AMP also exhibited both proliferation inhibition and GSH-decreasing effect on PHA-stimulated MNC as well as PGE₂. These results suggest that the immunosupressive effect of PGE₂ is mediated by the decreased generation of intracellular GSH, but not by the increased DNA strand breaks or apoptotic mechanism in the cells.     

Lymphocyte subpopulations in the blood of newborn infants

Assays of lymphocyte subpopulations and function have been applied to cells from the cord blood of twenty-four infants. The results are compared with those obtained in healthy adults. T cells, assayed by spontaneous rosette formation with sheep red blood cells (E rosettes) were present in lower proportion in cord (53%) than in adult blood (65%). There was a higher proportion of lymphocytes bearing stainable immunoglobulin in cord (32%) than in adult blood (22%). From the blood lymphocyte counts it was calculated that both T and B lymphocytes are present in greater numbers in the newborn infants' blood than in adults. Comparison of DNA synthesis showed that cord blood leucocytes had a higher spontaneous rate, but there were only minor differences in the lymphocyte mitotic response to phytohaemagglutinin (PHA). The response of cord blood lymphocytes was slightly lower to a submaximal stimulus and higher to a maximal stimulus. There was a correlation between the submaximal response and the proportion of E rosetting cells.

The most striking differences between infant and adult blood lymphocytes were in their cytotoxic activity against homologous target cells (Chang cells). Antibody-dependent cytotoxicity (K-cell activity) was readily detected using cord blood leucocytes, though it was lower than that of adult cells. PHA-induced cytotoxicity was very low in all cord blood samples, and in many cases was almost unmeasurable. This dissociation between the two types of cytotoxic activity is consistent with other evidence that they may be mediated by different cell types.

The assays were also applied to blood samples taken from five mothers of tested infants immediately after delivery. While some differences from normal adults were found with the mothers' lymphocytes they did not mirror those of the cord blood samples. This suggests that the pattern found for cord blood lymphocytes is not due to maternal factors crossing the placenta.

     

Effect of 6-day intense Kendo training on lymphocyte counts and its expression of CD95

This study examines the effects of 6-day intensive training on lymphocyte counts and their expression of CD95. Eight healthy Kendo athletes underwent 6-day Kendo training of about 310 min each day. Blood samples were collected at 2 weeks before (PRE), the first day (Day 1), third day (Day 3), fifth day (Day 5), and 1 week after the training period (POST) to determine lymphocyte counts and CD95 expression on CD95 lymphocytes (CD4⁺, CD8⁺) using flow cytometry. The total lymphocyte counts were significantly lower at Day 3 than at PRE. The CD8⁺ cell counts were significantly lower at Day 3 than at PRE. The percentage of CD95⁺ lymphocytes was significantly higher at Day 1 and Day 3 than at PRE. The percentage of CD8⁺CD95⁺ cells did not change significantly. The total lymphocyte counts decreased and a concomitant increase of CD95⁺ lymphocyte was observed, whereas the decrease in CD8⁺ cell counts was not associated with the increase in CD8⁺CD95⁺ cells. Therefore, short-term high-intensity exercise induced a decrease in the T lymphocyte counts without increasing in CD95⁺ expression.     

Effects of rearing temperature on hematological and biochemical parameters of great sturgeon (Huso huso Linnaeus, 1758) juvenile

The effect of environmental temperature changes on hematological and biochemical parameters of Huso huso juveniles was studied. Six-month-old juveniles with mean body weight of 69.2 ± 4.1 g were subjected to different temperatures (9–14°C, 15–20°C, and 21–26°C, respectively). The hematological parameters, ion Ca2+, glucose, and the cortisol concentrations were assessed after a period of 21 days rearing at these temperatures. The results show that hematocrit, Ca²⁺, and eosinophil were affected by different temperatures. Increasing temperature led to a significant increase (P < 0.05) in the hematocrit, Ca²⁺, and eosinophil, but white blood cell count, lymphocyte, cortisol, and glucose concentrations were decreased slightly (P > 0.05). The rest of the parameters showed no significant effect with increase in environmental temperature (P > 0.05). These data show significant effect of temperature on the blood parameters of great sturgeon.     

Translational Mini‐Review Series on Immunology of Vascular Disease: Accelerated atherosclerosis in vasculitis

The cutaneous leucocyte‐associated antigen receptor (CLA) can direct Leishmania‐specific T lymphocytes towards inflamed skin lesions. Homing receptors [CLA, lymphocyte‐associated antigen 1 (LFA‐1) or CD62L] were analysed in lymphocytes from blood and cutaneous leishmaniasis (CL) lesions. CL patients with active lesions (A‐CL) presented lower levels of T lymphocytes expressing the CLA⁺ phenotype (T CD4⁺ = 10·4% ± 7·5% and T CD8⁺ = 5·8% ± 3·4%) than did healthy subjects (HS) (T CD4⁺ = 19·3% ± 13·1% and T CD8⁺ = 21·6% ± 8·8%), notably in T CD8⁺ (P < 0·001). In clinically cured patients these percentages returned to levels observed in HS. Leishmanial antigens up‐regulated CLA in T cells (CLA⁺ in T CD4⁺ = 33·3% ± 14·1%; CLA⁺ in T CD8⁺ = 22·4% ± 9·4%) from A‐CL but not from HS. An enrichment of CLA⁺ cells was observed in lesions (CLA⁺ in T CD4⁺ = 45·9% ± 22·5%; CLA⁺ in T CD8⁺ = 46·4% ± 16·1%) in comparison with blood (CLA⁺ in T CD4⁺ = 10·4% ± 7·5%; CLA⁺ in T CD8⁺ = 5·8% ± 3·4%). Conversely, LFA‐1 was highly expressed in CD8⁺ T cells and augmented in CD4⁺ T from peripheral blood of A‐CL patients. In contrast, CD62L was not affected. These results suggest that Leishmania antigens can modulate molecules responsible for migration to skin lesions, potentially influencing the cell composition of inflammatory infiltrate of leishmaniasis or even the severity of the disease.