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1.
The existence of CD3(+)CD4(-)CD8(-) T cells in thymus and spleen has already been known. However, because of the presence of large amounts of thrombocytes in peripheral blood (PB), the proportion of CD3(+)CD4(-)CD8(-) T cells in PB has yet to be investigated. Therefore, the proportion of peripheral T cell-subsets was investigated in 6-week-old chickens. The percentage of CD3(+) cells, CD4(+) cells, CD8 alpha(+) cells, CD8 beta(+), and CD3(+)CD4(-)CD8(-) cells was 76%, 41%, 14%, 5%, and 15%, respectively. The proportion of CD3(+)CD4(-)CD8(-) cells in PB increased during egg-laying periods and in chickens treated with an analog of estrogen, while it decreased with age and in response to restraint stress. All of the CD3(+)CD4(-)CD8(-) cells expressed TCR1, and did not have NK activity. CD3(+)CD4(-)CD8(-) cells represent about 60% of peripheral TCR1(+) cells. These findings indicate that the proportion of CD3(+)CD4(-)CD8(-) cells is regulated by the endocrine and nerve systems.  相似文献   

2.
Fifteen clinically healthy calves were sampled every week during the first 5 weeks of life and thereafter every month until the age of 6 months. The percentages and absolute values of CD4+, CD8+ gammadelta TCR+ and WC1+ T cells, CD21+ B cells and NKp46+ NK cells were determined by flow cytometry, and the expression of the interleukin-2 receptor alpha chain (CD25) was measured to assess the level of activation of the lymphocyte subpopulations. Neutrophil phagocytosis, respiratory burst and bactericidal activity were measured in five different neutrophil function assays. Most of the parameters examined reached a stable level during the first 6 months of life. The proportions of CD4+ and CD8+ lymphocytes remained relatively stable during the study period, while there was a moderate decrease in the relative percentage of gammadelta T cells from birth to approximately 5 months of age. However, the absolute numbers of gammadelta T cells per millilitre of blood remained stable throughout the study period and did not display significant variation with age. The percentage of cells expressing the B-cell maturation marker CD21 increased significantly over the first 5 months of life. The proportion of NK cells showed substantial variation during the study. Marked differences in the relative proportions of the lymphocyte subpopulations were noted between the individual calves, and the individual ranking of the animals was largely maintained over time. CD25 expression was detected on a mean of 6.6% of the CD4+ cells, while a lower percentage of the other lymphocyte subpopulations expressed this receptor. Phagocytic activity was demonstrated in approximately 90% of the neutrophils, and this proportion remained stable during the entire study period, while respiratory burst activity showed a moderate decrease during the first 2 months of life. The present study shows that the T-cell subpopulations are present in peripheral blood of calves at levels comparable with adult values, while the B-cell population increases significantly with age. The decrease in the relative percentage of gammadelta T cells appears to be attributable to an increase in the absolute numbers of CD4+ and CD21+ cells, rather than a change in absolute gammadelta T-cell numbers. Furthermore, the results indicate that the neutrophilic granulocytes are functional and able to mount an effective response in young calves from the first week of life.  相似文献   

3.
Natural killer (NK) cells have been considered to be a group of lymphocytes lacking clonally distributed receptors for antigens typical of T cells and B cells. In some mammalian species, including humans, a subpopulation of CD8+ peripheral blood lymphocytes (PBLs) exhibits NK activity. This NK subpopulation has not been well characterized in mammals and its characterization is particularly poor in the dog. In this study, we demonstrated that a subset of canine CD8+ cells derived from PBLs and lymphokine (IL-2)-activated killers (LAKs) of PBLs that was CD3+, CD4?, CD21?, CD5lo, α/βTCR+, and γ/δTCR? contained substantially higher levels of mRNAs for NK cell-related receptors (NKp30, NKp44, NKG2D, 2B4, and CD16 for PBL, and NKG2D and CD56 for LAK) than the corresponding CD8? cells. This subset of CD8+ lymphocytes derived from LAKs also displayed significantly higher NK cytotoxic activity than the corresponding CD8? cells. In contrast, CD8+ cells derived from nonstimulated PBLs showed very low levels of NK cytotoxic activity. Our results indicate that, in IL-2-stimulated PBLs, canine CD8+ cells are an important subset associated with NK cytotoxic activity.  相似文献   

4.
The studies were carried out on Balb/c mice exposed to restraint stress twice for 12 h at 24 h intervals. Prior to stress exposure, the mice were treated with calf thymus extract (TFX - Jelfa) i.p. at a dose of 10 mg/kg, ten times at 24 h intervals. TFX was used per se or with zinc ions interaction, by adding zinc ions (as sulfate salt) to drinking water at a dose of 72 microg/mouse per day. The results obtained show that restraint stress dramatically decreased the total number of thymocytes and splenocytes which is also accompanied by decreasing weight ratio of the thymus and spleen. The decreasing number of thymic and spleen cells corresponded to a diminishing percentage of immature, double-positive CD4+CD8+ thymocytes, mature single-positive CD4+ thymic cells and CD4+, CD8+ and CD19+ splenocytes. Changes in the number of thymic cells affect their activity, which is expressed as a decreased proliferative response of thymocytes stimulated in vitro with concanavalin A (Con A) and phytohaemagglutinin (PHA). Besides, exposure to the restraint stress decreased interleukin-1 (IL-1) production by murine intraperitoneal macrophages stimulated in vitro with lipopolisacharide (LPS) from E. coli. Previous treatment with TFX counteracted restraint stress-induced immunosuppression, which is expressed as partial normalisation of the total number of thymic and spleen cells, accelerated regeneration of these two lymphatic organs, shortned suppressive action of restraint stress on the percentage of immature CD4+CD8+ thymocytes and CD4+ splenocytes and in total normalisation of the CD4+ thymocytes and CD8+ splenocytes. TFX administered prior to restraint stress not only counteracted the suppresive effects of stress on the proliferative activity of thymic cells stimulated in vitro with Con A and PHA, but also augmented the proliferative response of these cells to two mitogens. The immunorestorative effect of TFX was augmented by zinc supplementation.  相似文献   

5.
ABSTRACT: Natural killer (NK) cells are well recognized as playing a key role in innate immune defence through cytokine production and cytotoxic activity; additionally recent studies have identified several novel NK cell functions. The ability to study NK cells in the sheep has been restricted due to a lack of specific reagents. We report the generation of a monoclonal antibody specific for ovine NKp46, a receptor which in a number of mammals is expressed exclusively in NK cells. Ovine NKp46+ cells represent a population that is distinct from CD4+ and γδ+ T-cells, B-cells and cells of the monocytic lineage. The NKp46+ cells are heterogenous with respect to expression of CD2 and CD8 and most, but not all, express CD16 - characteristics consistent with NK cell populations in other species. We demonstrate that in addition to populations in peripheral blood and secondary lymphoid organs, ovine NKp46+ populations are also situated at the mucosal surfaces of the lung, gastro-intestinal tract and non-gravid uterus. Furthermore, we show that purified ovine NKp46+ populations cultured in IL-2 and IL-15 have cytotoxic activity that could be enhanced by ligation of NKp46 in re-directed lysis assays. Therefore we conclude that ovine NKp46+ cells represent a population that by phenotype, tissue distribution and function correspond to NK cells and that NKp46 is an activating receptor in sheep as in other species.  相似文献   

6.
旨在系统分析伯氏疟原虫感染引起宿主T细胞、NK细胞、Tim-3表达及细胞因子的变化。选取64只雌性C57BL/6小鼠随机分为8组,每组8只,分别于感染后0、4、7、9、11、13、16和19 d获取小鼠脾及外周血免疫细胞,利用流式细胞术检测小鼠主要免疫细胞亚群及免疫检查点分子Tim-3表达水平的变化;同时检测血清中细胞因子的变化。结果表明,感染疟原虫后,小鼠脾CD3+CD4+ T细胞、CD3+CD8+ T细胞及NK细胞的比例均逐渐降低(P<0.01),且伴随着3种细胞Tim-3表达量的升高(P<0.01)。小鼠外周血CD3+CD4+ T细胞的比例呈先降低后升高趋势,CD3+CD8+ T细胞的比例呈先升高后降低趋势(P<0.05);小鼠外周血CD3-NK1.1+细胞的比例呈先降低后升高趋势,但感染末期,其比例仍低于未感染组(P<0.05)。Tim-3分子在外周血CD3+CD4+ T细胞、CD3+CD8+ T细胞及CD3-NK1.1+细胞的表达均显著升高(P<0.05)。感染疟原虫后,小鼠血清中促炎细胞因子IL-2的分泌量均显著高于未感染组(P<0.05);促炎细胞因子IFN-γ、TNF-α和IL-6在血清中分泌均呈先升高后降低趋势(P<0.05);具有免疫抑制作用的细胞因子IL-10呈逐渐升高趋势,且感染后期急剧升高(P<0.001)。以上结果表明,感染疟原虫后,小鼠的特异性免疫反应发挥了一定的杀伤作用,但由于Tim-3免疫检查点分子及一些发挥免疫抑制作用的细胞因子(IL-10)的过度表达,有利于疟原虫逃避宿主的免疫捕杀作用。该研究提示了从宿主免疫抑制角度研究疟原虫感染的重要性。  相似文献   

7.
Free-ranging African lion (Panthera leo) peripheral blood mononuclear cells (PBMC) were examined using flow cytometry and antibodies developed for use in the domestic cat to determine if phenotypic changes occurred in lion lymphocytes as a result of feline immunodeficiency virus (FIV) infection. The percentage of CD8 cells from lion peripheral blood was considerably lower than in the domestic cat. Lions with elevated levels of CD8+ cells were typically infected with FIV, similar to observations in the domestic cat. Antibodies against the alpha chain of the CD8 receptor (monoclonal antibody (mAb) 3.357) did not react consistently in all lions examined. Flow cytometric analysis determined that approximately 82 and 80% of the animals from Kruger and Hluhluwe-Umfolozi National Parks in South Africa reacted with the monoclonal antibody against the alpha chain of CD8 receptor, while only 17% of the lions in Etosha National Park in Namibia cross-reacted with the CD8alpha chain. There was no apparent correlation between FIV status and CD8alpha chain reactivity. The relative isolation of Etosha from the other two parks could explain the marked difference in CD8alpha chain expression and suggests that lions similar to other mammalian species demonstrate polymorphic expression of the CD8alpha chain (197).  相似文献   

8.
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10.
为了评价硫酸化人参皂苷Rh2化学修饰前后免疫活性变化,采用MTT法及流式细胞术研究体外对ConA促鸡外周血淋巴细胞增殖的影响,采用乳酸脱氢酶释放法研究体外对鸡外周血NK细胞杀伤活性的影响。结果表明:Rh2、Rh2溶剂及硫酸化Rh2低浓度时都能促进淋巴细胞增殖,高浓度时能抑制淋巴细胞增殖,Rh2溶剂及硫酸化Rh2都显著(P〈0.05)或极显著(P〈0.01)高于同浓度的Rh2。Rh2及Rh2溶剂都能显著促进鸡外周血NK细胞杀伤活性,但Rh2极显著(P〈0.01)低于同浓度Rh2溶剂,而硫酸化Rh2表现一定促进作用。结果提示:Rb2体外能抑制免疫活性,化学修饰后的硫酸化Rh,体外能促进免疫活性。  相似文献   

11.
12.
Changes in subsets of peripheral blood mononuclear cells and lymphocyte blastogenesis reaction were observed after ozonated autohemoadministration (OAHA) in calves. Ten healthy calves were used in this study. After OAHA, CD8+ cells, CD14+ cells and WCl+cells increased (p<0.05). The level of lymphocyte blastogenesis stimulated by PHA decreased after OAHA. A significant increase in serum IL-6 activity was observed in OAHA calves. These results suggested that OAHA induced immunological changes in calves.  相似文献   

13.
为了研究荷斯坦奶牛受到双翅目昆虫侵袭时奶牛个体所表现的护身行为、外周血液中淋巴细胞亚群的变化规律,试验期间每日跟踪观察奶牛护身行为1 h,记录每5 min内侵袭奶牛的双翅目昆虫数目和奶牛的护身行为出现次数,定时采血用流式细胞仪检测外周血液中CD3+、CD4+、CD8+ T淋巴细胞和CD21+B淋巴细胞等的变化规律.结果表明:奶牛护身行为随飞来昆虫的数量而变化;外周血液中的CD3+、CD4+、CD21+水平随双翅目昆虫数量的增多而降低;CD8+水平随双翅目昆虫数量的增多而升高.  相似文献   

14.
The number of lymphocytes in chicken blood samples decreased and the number of heterophils increased in response to stressors and to increasing levels of corticosterone in the chicken feed. The ratio of heterophils to lymphocytes was less variable than the number of heterophil or lymphocyte cells, and the range of values for this ratio was greater than the range of values for heterophils and lymphocytes among control and experimental groups. The heterophil/lymphocyte ratio appears to be a more reliable indicator of levels of corticosterone in the feed and to social stress than were the plasma corticosteroid levels.  相似文献   

15.
Borna disease virus (BDV) is a neurotropic agent with capacity to cause encephalomyelitis in a wide range of animal species, including horses and cats. Recent studies also point to a link between BDV and human neuropsychiatric disorders. The pathogenesis of Borna disease (BD) has been proposed to be immune-mediated, mainly through the effects of cytotoxic T cells. We used flow cytometric analysis in order to characterize the peripheral and intracerebral T cell immune response in cats naturally infected with BDV. Our results show the presence of two different CD8+ cell populations (CD8+low and CD8+high) in the blood, spleen and brain of these cats. In the brain, CD8+low cells predominated over CD8+high cells. Since CD8+low cells have been suggested to represent a non-MHC-restricted T cell population, the recruitment of such cells to the brains of BDV-infected cats could possibly be of importance for the clearance of virus from neurones.  相似文献   

16.
We have analysed natural killer (NK) cytotoxic activity in peripheral blood and ascitic fluids of patients with advanced stage of ovarian epithelial carcinoma. All patients displayed low NK activity in peripheral blood and virtually no cytotoxicity in ascitic fluids. NK activity in ascitic fluids could be substantially augmented after regional administration of virus-modified tumor cell extracts (VMTE), and that in peripheral blood after culture of effector cells with interleukin-2 (IL-2) in vitro. Activated NK cells displayed cytotoxic activity against NK-sensitive and NK-resistant tumor cell lines as well as against fresh ovarian tumors. Parallelism was found between regional NK augmentation and regression of malignant ascites. The latter observation suggests possible NK cell role in defense against ovarian tumors.  相似文献   

17.
The lymphocyte subpopulations of peripheral blood of normal lambs and lambs experimentally infected with bovine respiratory syncytial virus (RSV) were analysed by flow cytometry, using a panel of monoclonal antibodies against specific lymphocyte epitopes. Experimental infection with bovine RSV was characterized by a significant rise in SBU-T8+ (CD8+ or cytotoxic) T cells and a significant reduction in SBU-T4+ (CD4+ or helper) T cells and B (LCA p220+) lymphocytes (P less than 0.05). The helper/suppressor (CD4/CD8) ratio was reduced from 3.91 on the day of experimental infection to 1.13 on 10 days after experimental infection (P less than 0.001). The total number of SBU-T4+ (CD4+) and B cells returned to pre-inoculation values 14 days after experimental infection but the helper/suppressor ratio remained depressed up to 21 days post-inoculation.  相似文献   

18.
Cytotoxic T lymphocytes (CTL) against mouse P815 cells were detected after stimulation of porcine peripheral blood mononuclear cells (PBMC) with irradiated Balb/c splenocytes. In vivo priming prior to in vitro stimulation slightly enhanced CTL activity, but lysis of targets was undetectable from lymphocytes from non-immune or immune animals that were not cultured with mouse splenocytes. After primary culture with Balb/c (H-2d) splenocytes, specific killing of P815 (H-2d) targets and not L929 (H-2k) targets indicated that recognition was specific for the H-2 locus. Similarly, CTL primed by mouse cells from either of two congenic strains recognized targets with alleles homologous to the stimulating cells. The anti-murine CTL was confirmed to be a CD8+ T cell based on studies using specific monoclonal antibodies to the porcine CD4 or CD8 cells. The cells responsible for the cytotoxicity of P815 targets lacked the characteristics of non-specific NK cells because (1) naive PBMC were unable to lyse NK targets (K562 cells) during the 4 h cytotoxic assay and (2) CTL killing of P815 targets increased with time after primary stimulation, whereas killing of K562 cells remained low at all times. These results suggest that porcine CTL can be readily generated against the xenogeneic mouse major histocompatibility complex.  相似文献   

19.
The lymphocyte subpopulations in the peripheral blood of normal sheep and sheep experimentally infected with Cytoecetes phagocytophila, the causative agent of tick-borne fever, were analysed by flow cytometry, using a panel of monoclonal antibodies against specific lymphocyte epitopes. Experimental infection with tick-borne fever was characterised by a significant reduction in the total number of circulating lymphocytes six days after experimental infection (P less than 0.001). This lymphocytopenia was associated with a significant reduction in the number of B (LCAp220+) and T (CD5+) lymphocytes (P less than 0.001) but there was a significant increase in the number of cells which were neither T nor B (CD5-LCAp220-) cells (P less than 0.01). The reduction in the number of T lymphocytes was due to reduced numbers of circulating CD4+ (helper) T cells, CD8+ (cytotoxic/suppressor) T cells and those with the pan T cell marker (CD5+) but without CD4 or CD8 epitopes (CD4-CD8-). All lymphocytes returned to preinoculation levels 13 to 16 days after experimental infection.  相似文献   

20.
1. An experiment was carried out to evaluate the effect of early feed restriction (FR) on immunocompetence of Ross and Arian chickens with separated sexes under heat stress (HS) conditions. 2. Chickens consumed feed ad libitum (AL) or were restricted on alternate days from 11 to 20 d of age. From 35 to 41 d of age, the HS groups were exposed to a high ambient temperature of 39 +/- 1 degreesC for 7 h each day, while the thermoneutral groups (TN) were at 33 degrees C. 3. At 21 and 42d of age, the percentage of CD4+ (helper T cells) and CD8+ (cytotoxic T cells) were determined by flow cytometry. Antibody response to sheep red blood cells (SRBC) and heterophil/lymphocyte (H/L) ratio were determined on d 21 and 42. 4. On d 21, FR elevated the CD4+, antibody titre and H/L ratio, but it decreased the CD8+ T cells. On d 42, HS decreased CD4+, CD8+, and antibody titre, but it increased H/L ratio. Under TN conditions, FR chickens had higher CD4+ than AL chickens. On d 42, FR/HS chickens had higher CD4+ and antibody titre, but they had lower CD8+ and H/L ratio than AL/HS chickens. 5. On d 42, the TN-Ross strain had lower CD4+, but they had higher CD8+ and antibody titres than the TN-Arian strain. On d 42, the HS-Arian strain had higher antibody titres and a lower H/L ratio than the HS-Ross strain. 6. Male chickens had higher CD4+, CD8+, antibody titres and H/L ratios 25 in all treatment groups. 7. In conclusion, FR early in life reduced some of the negative effects of the heat stress on the immune system of broiler chickens when exposed to high environmental temperatures later in life.  相似文献   

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