Memory CD4+ and CD8+ T lymphocyte proliferation in vaccinated dairy cows with different histories of Staphylococcus aureus mastitis.

Staphylococcus aureus mastitis constitutes a serious threat to dairy cows. The reasons why available vaccines are not fully effective remain poorly understood; thus, in the present study, we investigated CD4+ and CD8+ T lymphocyte proliferation in dairy cows vaccinated with a polyvalent mastitis vaccine that had distinct precedent Staphylococcus aureus mastitis. We studied 17 S. aureus-infected dairy cows (11 vaccinated and six unvaccinated) and eight vaccinated healthy dairy cows with no previous S. aureus mastitis infections. Flow cytometry was used to assess lymphocyte proliferation using an anti-Ki67 antibody, and monoclonal antibodies were used to identify T cell subsets. S. aureus-infected cows exhibited reduced overall lymphocyte proliferation, including CD4+ T lymphocyte proliferation, and memory lymphocyte proliferation in response to S. aureus isolate stimulus. Immunization did not influence the expansion of blood lymphocyte populations. Furthermore, CD8+ T cells, memory CD8+ T lymphocytes, and effector memory CD8+ T lymphocytes displayed reduced proliferation 21 days after the third vaccine dose compared with before vaccination at time zero. The present data demonstrates an overall negative regulation of the T-cell response suggesting its detrimental impact leading to the persistence of S. aureus intramammary infections. Furthermore, the lack of vaccination effect on T-cell mediated immunity (e.g., proliferation) may be related to poor vaccine efficacy.

Phytochemical profile and antiproliferative activity of human lymphocytes of Gomphrena virgata Mart. (Amaranthaceae).

Gomphrena virgata Mart. popularly known as 'Cangussu-branco', is used in Brazilian folk medicine to treat inflammations and infections. This work aimed to carry out phytochemical analysis and evaluate the anti-inflammatory potential of Gomphrena virgata. In the phytochemical investigation, in addition to the presence of two ecdysteroids, 20 R-dihydroxyecdysone and 20-hydroxyecdysone, identified by HPLC-PDA-MS and NMR, 22 compounds were identified by GC-MS. In the cytotoxicity study, the aqueous extract of the roots of this species did not show in vitro toxicity of PBMCs in the concentrations of 250, 500 and 1000 µg/mL when analyzed by the trypan blue exclusion method. Also, it was effective in reducing lymphocyte proliferation, stimulated with the mitogen PHA, by 26.02%, 48.57% and 50.49% when compared to dexamethasone, respectively. In this work we present information about the phytochemicals of G. virgata, showing that the species is promising in obtaining compounds with medicinal potential mainly anti-inflammatory potential.

Immunomodulatory Protective Effects of Rb9 Cyclic-Peptide in a Metastatic Melanoma Setting and the Involvement of Dendritic Cells.

The cyclic VHCDR3-derived peptide (Rb9) from RebMab200 antibody, directed to a NaPi2B phosphate-transport protein, displayed anti-metastatic melanoma activity at 50-300 µg intraperitoneally injected in syngeneic mice. Immune deficient mice failed to respond to the peptide protective effect. Rb9 induced increased CD8+ T and low Foxp3+ T cell infiltration in lung metastases and high IFN-γ and low TGF-ß in lymphoid organs. The peptide co-localized with F-actin and a nuclear site in dendritic cells and specifically bound to MIF and CD74 in a dot-blot setting. Murine bone-marrow dendritic cells preincubated with Rb9 for 6 h were treated with MIF for short time periods. The modulated responses showed stimulation of CD74 and inhibition of pPI3K, pERK, and pNF-κB as compared to MIF alone. Rb9 in a melanoma-conditioned medium, stimulated the M1 type conversion in bone marrow-macrophages. Functional aspects of Rb9 in vivo were studied in therapeutic and prophylactic protocols using a melanoma metastatic model. In both protocols Rb9 exhibited a marked anti-melanoma protection. Human dendritic cells were also investigated showing increased expression of surface markers in response to Rb9 incubation. Rb9 either stimulated or slightly inhibited moDCs submitted to inhibitory (TGF-ß and IL-10) or activating (LPS) conditions, respectively. Lymphocyte proliferation was obtained with moDCs stimulated by Rb9 and tumor cell lysate. In moDCs from cancer patients Rb9 exerted immunomodulatory activities depending on their functional status. The peptide may inhibit over-stimulated cells, stimulate poorly activated and suppressed cells, or cause instead, little phenotypic and functional alterations. Recently, the interaction MIF-CD74 has been associated to PD-L1 expression and IFN-γ, suggesting a target for melanoma treatment. The effects described for Rb9 and the protection against metastatic melanoma may suggest the possibility of a peptide reagent that could be relevant when associated to modern immunotherapeutic procedures.

Effects of polychlorinated biphenyls (PCB) on California sea lion (Zalophus californianus) lymphocyte functions upon in vitro exposure.

Polychorinated biphenyl (PCB) congeners are a cause for concern due to their persistence in the environment, their lipophilic properties that cause them to bio-accumulate in top predators, and their adverse effects on mammalian health. For example, the common urogenital carcinoma reported in California sea lions (Zalophus californianus) (CSL) is associated with high tissue levels of PCBs, but the mechanisms responsible for this association are unknown. This study investigated the effect of exposure to six PCB congeners and a congener mix at low and environmentally relevant concentrations on NK cell-like and T cell activity using in vitro assays on cryopreserved lymph node mononuclear cells isolated from dead CSL. Non dioxin-like congeners 153 and 180 increased lymphocyte proliferation at 5 and 10 ppm, while congener 138 decreased proliferation by up to 43% at 15 ppm. Dioxin-like PCBs 118 and 169 did not affect lymphocyte proliferation, while the effects of congener 105 depended on the mitogen concentration; these did not correlate with their predicted toxic equivalent factors. NK cell-like activity was affected only by the highest concentration of PCBs tested; it was increased by non-dioxin-like congeners 138 and 153, and decreased by dioxin-like congener 169. The PCB congener mix suggested that the effects of PCB congeners were not simply additive. Our results concur with effects of PCBs reported for other pinniped's lymphocytes and add further experimental support to the observation that dioxin-like PCBs are not the most toxic congeners for marine mammals, contrary to effects in other species. This is the first evidence of in vitro suppression of NK cell-like cytotoxicity by a dioxin-like congener in a pinniped. More importantly, the observed results suggest that PCBs can modulate the CSL immune system, increasing exposed individuals' susceptibility to viral and oncogenic challenges.

Behavioral Fever Drives Epigenetic Modulation of the Immune Response in Fish.

Ectotherms choose the best thermal conditions to mount a successful immune response, a phenomenon known as behavioral fever. The cumulative evidence suggests that behavioral fever impacts positively upon lymphocyte proliferation, inflammatory cytokine expression, and other immune functions. In this study, we have explored how thermal choice during infection impacts upon underpinning molecular processes and how temperature increase is coupled to the immune response. Our results show that behavioral fever results in a widespread, plastic imprint on gene regulation, and lymphocyte proliferation. We further explored the possible contribution of histone modification and identified global associations between temperature and histone changes that suggest epigenetic remodeling as a result of behavioral fever. Together, these results highlight the critical importance of thermal choice in mobile ectotherms, particularly in response to an infection, and demonstrate the key role of epigenetic modification to orchestrate the thermocoupling of the immune response during behavioral fever.

Inhibitory effect of the Pseudobrickellia brasiliensis (Spreng) R.M. King & H. Rob. aqueous extract on human lymphocyte proliferation and IFN-γ and TNF-α production in vitro

Pseudobrickellia brasiliensis (Asteraceae) is a plant commonly known as arnica-do-campo and belongs to the native flora of the Brazilian Cerrado. The alcoholic extract of the plant has been used as an anti-inflammatory agent in folk medicine, but the biological mechanism of action has not been elucidated. The present study evaluated the composition of P. brasiliensis aqueous extract and its effects on pro-inflammatory cytokine production and lymphocyte proliferation. The extracts were prepared by sequential maceration of P. brasiliensis leaves in ethanol, ethyl acetate, and water. Extract cytotoxicity was evaluated by trypan blue exclusion assay, and apoptosis and necrosis were measured by staining with annexin V-FITC and propidium iodide. The ethanolic (ETA) and acetate (ACE) extracts showed cytotoxic effects. The aqueous extract (AQU) was not cytotoxic. Peripheral blood mononuclear cells stimulated with phorbol myristate acetate and ionomycin and treated with AQU (100 μg/mL) showed reduced interferon (IFN)-γ and tumor necrosis factor (TNF)-α expression. AQU also inhibited lymphocyte proliferative response after nonspecific stimulation with phytohemagglutinin. The aqueous extract was analyzed by liquid chromatography coupled with photodiode array detection and mass spectrometry. Quinic acid and its derivatives 5-caffeoylquinic acid and 3,5-dicaffeoylquinic acid, as well as the flavonoids luteolin and luteolin dihexoside, were detected. All these compounds are known to exhibit anti-inflammatory activity. Taken together, these findings demonstrate that P. brasiliensis aqueous extract can inhibit the pro-inflammatory cytokine production and proliferative response of lymphocytes. These effects may be related to the presence of chemical substances with anti-inflammatory actions previously reported in scientific literature.

Effects of polysaccharide from Ophiopogon japonicus on immune response to Newcastle disease vaccine in chicken

In order to investigate the immune enhancement effects of Ophiopogon japonicus polysaccharide Ophiopogon japonicus (OJPS) on Newcastle disease (ND) live vaccine, chickens vaccinated against ND live vaccine was orally administered with the OJPS at high, medium and low concentrations respectively. In negative control group, chickens were given orally equal volume of physiological saline. On day 14, 21 and 28, the serum antibody titer, erythrocyte-C3b receptor rosette rate (E-C3bRR), erythrocyte-C3b immune complex rosette rate (E-ICRR) and peripheral lymphocyte proliferation were measured. The results showed that at most time points, the antibody titer, peripheral lymphocyte proliferation, E-C3bRR and elimination rate of immune complex of three OJPS administrating groups were significantly higher (P<0.05) than those in negative control group. It indicated that OJPS could significantly improve the immune efficacy of Newcastle disease live vaccine, Ophiopogon japonicus polysaccharide possessed synergistical immunoenhancement.(AU)

Effects of polysaccharide from Ophiopogon japonicus on immune response to Newcastle disease vaccine in chicken

In order to investigate the immune enhancement effects of Ophiopogon japonicus polysaccharide Ophiopogon japonicus (OJPS) on Newcastle disease (ND) live vaccine, chickens vaccinated against ND live vaccine was orally administered with the OJPS at high, medium and low concentrations respectively. In negative control group, chickens were given orally equal volume of physiological saline. On day 14, 21 and 28, the serum antibody titer, erythrocyte-C3b receptor rosette rate (E-C3bRR), erythrocyte-C3b immune complex rosette rate (E-ICRR) and peripheral lymphocyte proliferation were measured. The results showed that at most time points, the antibody titer, peripheral lymphocyte proliferation, E-C3bRR and elimination rate of immune complex of three OJPS administrating groups were significantly higher (P < 0.05) than those in negative control group. It indicated that OJPS could significantly improve the immune efficacy of Newcastle disease live vaccine, Ophiopogon japonicus polysaccharide possessed synergistical immunoenhancement.(AU)

IRF2BP2 transcriptional repressor restrains naive CD4 T cell activation and clonal expansion induced by TCR triggering.

CD4 T cell activation and differentiation mechanisms constitute a complex and intricate signaling network involving several regulatory proteins. IRF2BP2 is a transcriptional repressor that is involved in gene-expression regulation in very diverse biologic contexts. Information regarding the IRF2BP2 regulatory function in CD4 T lymphocytes is very limited and suggests a role for this protein in repressing the expression of different cytokine genes. Here, we showed that Irf2bp2 gene expression was decreased in CD4 T cells upon activation. To investigate the possible regulatory roles for IRF2BP2 in CD4 T cell functions, this protein was ectopically expressed in murine primary-activated CD4 T lymphocytes through retroviral transduction. Interestingly, ectopic expression of IRF2BP2 led to a reduction in CD25 expression and STAT5 phosphorylation, along with an impaired proliferative capacity. The CD69 expression was also diminished in IRF2BP2-overexpressing cells, whereas CD44 and CD62L levels were not altered. In vivo, transferred, IRF2BP2-overexpressing, transduced cells displayed an impaired expansion capacity compared with controls. Furthermore, overexpression of IRF2BP2 in differentiated Th cells resulted in slightly reduced IL-4 and pro-TGF-ß production in Th2 and iTregs but had no effect on IFN-γ or IL-17 expression in Th1 and Th17 cells, respectively. Taken together, our data suggest a role for IRF2BP2 in regulating CD4 T cell activation by repressing proliferation and the expression of CD25 and CD69 induced by TCR stimuli.

Assessment of human lymphocyte proliferation associated with metabolic syndrome.

BACKGROUND: Metabolic syndrome (MetS), a cluster of various metabolic conditions, has become epidemic and causes increased morbidity and mortality. PURPOSE: The aim of this study was to compare lymphocyte proliferation under two different stimuli, Concanavalin A (ConA) and insulin, in a group of patients with MetS (Group 1) and a healthy group (Group 2). METHODS: Group 1 consisted of 53 patients who met the diagnostic criteria for MetS. Group 2 consisted of 63 patients without MetS. All individuals were evaluated for lipid profile and glycemia. Lymphocyte extraction and culture were performed for each subject and lymphocyte proliferation was assessed using the Alamar blue technique. RESULTS: There was no gender difference between both groups, but in terms of age, there was a significant difference. The use of Con A at concentrations of 1 and 5 µg/mL induced a high lymphocyte proliferation in both groups. In contrast, when different concentrations of insulin were added, no significant changes in lymphocyte proliferation were observed. However, the proliferation of lymphocytes was significantly higher in Group 1 compared to Group 2 under insulin stimulus, which did not happen under ConA stimulation. Even after age and gender correction, this difference was maintained. CONCLUSIONS: The increased lymphocyte proliferative response to insulin in patients with MetS found in this study suggests a role of the lymphocyte response to insulin in the pathophysiology of MetS. This response may be used as an immuno-biological marker for MetS, although further studies to evaluate its clinical usefulness need to be conducted.

Modulation of glutathione intracellular levels alters the spontaneous proliferation of lymphocyte from HTLV-1 infected patients.

The human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus associated with neoplasias and inflammatory diseases, such as adult T-cell leukemia/lymphoma and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1-infected individuals present a spontaneous T lymphocyte proliferation. This phenomenon is related to the HTLV-1-proviral load and the persistence of the infection. Viral proteins induce many cellular mediators, which can be associated with the abnormal cellular proliferation. The intracellular levels of glutathione (GSH) are important to modulate the cellular proliferation. The aim of this study was to investigate the correlation between the modulation of intracellular GSH levels and the spontaneous lymphocyte proliferation during the HTLV-1 infection. Intracellular GSH level can be modulated by using dl-buthionine-[S,R]-sulfoximine (BSO, GSH synthesis inhibitor) and N-acetylcysteine (NAC, peptide precursor). Our results demonstrated that BSO was capable of inducing a decrease in the spontaneous proliferation of PBMC derived from HTLV-1 carriers. On the other hand, the GSH precursor induces an increase in mitogen-stimulated cellular proliferation in infected and uninfected individuals. Similar results were observed by the inhibition of ABCC1/MRP1 protein, augmenting the mitogen-induced proliferation. This effect can be related with an increase in the GSH levels since ABCC1/MRP1 transports GSH to the extracellular medium. There was a significant difference on the expression of CD69 and CD25 molecules during the lymphocyte activation. We did not observe any alterations on CD25 expression induced by BSO or NAC. However, our results demonstrated that NAC treatment induced an increase in CD69 expression on unstimulated CD8(+) T lymphocytes obtained from HTLV-1 infected individuals, healthy donors and HTLV carriers. Therefore, our results suggest that the cellular proliferation promoted by the infection with HTLV-1 and the activation phenotype of CD8(+) T lymphocytes can be regulated by changing the intracellular GSH levels; suggesting the modulation of these intracellular levels as a new approach for the treatment of pathologies associated with the HTLV-1 infection.

Effects of polysaccharide from Chuanminshen violaceum on immune response of Newcastle disease vaccine in chicken / Effects of polysaccharide from Chuanminshen violaceum on immune response of Newcastle disease vaccine in chicken

Background: Newcastle disease (ND), caused by avian paramyxovirus serotype 1 (APMV-1), also known as Newcastle disease virus (NDV), is regarded as one of the two most devastating diseases of poultry with the characteristics of serious disease and high flock mortality. It causes severe economic losses in domestic poultry, especially in chickens. At present, there were no effective drugs to treat this disease and the main method to control ND was vaccination. Moreover, new strains of virus resistant to chemotherapy continue to emerge, so does the need for a safe and effective vaccine. The immune adjuvant can make vaccine generate a strong immune response providing long-term protection against infection. With commonly usage of some immune adjuvants (e.g. mineral oil and aluminium hydroxide), many problems were occurred, such as side effects, strong local stimulation and carcinogenesis, together with complicated preparation, or failure to increase immunogenicity of weak antigen and so on. Botanical polysaccharides, as a new type of adjuvant or immunopotentiator, had become the hot research area because of their less side effects and no toxicity. The purpose of this research was to observe whether Chuanminshen violaceum polysaccharide (CVPS) possessed synergistical immunoenhancement, and offer the theoretical evidence for developing potential new-type adjuvant. Materials, Methods &a

Background: Newcastle disease (ND), caused by avian paramyxovirus serotype 1 (APMV-1), also known as Newcastle disease virus (NDV), is regarded as one of the two most devastating diseases of poultry with the characteristics of serious disease and high flock mortality. It causes severe economic losses in domestic poultry, especially in chickens. At present, there were no effective drugs to treat this disease and the main method to control ND was vaccination. Moreover, new strains of virus resistant to chemotherapy continue to emerge, so does the need for a safe and effective vaccine. The immune adjuvant can make vaccine generate a strong immune response providing long-term protection against infection. With commonly usage of some immune adjuvants (e.g. mineral oil and aluminium hydroxide), many problems were occurred, such as side effects, strong local stimulation and carcinogenesis, together with complicated preparation, or failure to increase immunogenicity of weak antigen and so on. Botanical polysaccharides, as a new type of adjuvant or immunopotentiator, had become the hot research area because of their less side effects and no toxicity. The purpose of this research was to observe whether Chuanminshen violaceum polysaccharide (CVPS) possessed synergistical immunoenhancement, and offer the theoretical evidence for developing potential new-type adjuvant. Materials, Methods &a

Effects of polysaccharide from Chuanminshen violaceum on immune response of Newcastle disease vaccine in chicken / Effects of polysaccharide from Chuanminshen violaceum on immune response of Newcastle disease vaccine in chicken

Background: Newcastle disease (ND), caused by avian paramyxovirus serotype 1 (APMV-1), also known as Newcastle disease virus (NDV), is regarded as one of the two most devastating diseases of poultry with the characteristics of serious disease and high flock mortality. It causes severe economic losses in domestic poultry, especially in chickens. At present, there were no effective drugs to treat this disease and the main method to control ND was vaccination. Moreover, new strains of virus resistant to chemotherapy continue to emerge, so does the need for a safe and effective vaccine. The immune adjuvant can make vaccine generate a strong immune response providing long-term protection against infection. With commonly usage of some immune adjuvants (e.g. mineral oil and aluminium hydroxide), many problems were occurred, such as side effects, strong local stimulation and carcinogenesis, together with complicated preparation, or failure to increase immunogenicity of weak antigen and so on. Botanical polysaccharides, as a new type of adjuvant or immunopotentiator, had become the hot research area because of their less side effects and no toxicity. The purpose of this research was to observe whether Chuanminshen violaceum polysaccharide (CVPS) possessed synergistical immunoenhancement, and offer the theoretical evidence for developing potential new-type adjuvant. Materials, Methods &a

Background: Newcastle disease (ND), caused by avian paramyxovirus serotype 1 (APMV-1), also known as Newcastle disease virus (NDV), is regarded as one of the two most devastating diseases of poultry with the characteristics of serious disease and high flock mortality. It causes severe economic losses in domestic poultry, especially in chickens. At present, there were no effective drugs to treat this disease and the main method to control ND was vaccination. Moreover, new strains of virus resistant to chemotherapy continue to emerge, so does the need for a safe and effective vaccine. The immune adjuvant can make vaccine generate a strong immune response providing long-term protection against infection. With commonly usage of some immune adjuvants (e.g. mineral oil and aluminium hydroxide), many problems were occurred, such as side effects, strong local stimulation and carcinogenesis, together with complicated preparation, or failure to increase immunogenicity of weak antigen and so on. Botanical polysaccharides, as a new type of adjuvant or immunopotentiator, had become the hot research area because of their less side effects and no toxicity. The purpose of this research was to observe whether Chuanminshen violaceum polysaccharide (CVPS) possessed synergistical immunoenhancement, and offer the theoretical evidence for developing potential new-type adjuvant. Materials, Methods &a

Effects of polysaccharide from Chuanminshen violaceum on immune response of newcastle disease vaccine in chicken

Background: Newcastle disease (ND), caused by avian paramyxovirus serotype 1 (APMV-1), also known as Newcastle disease virus (NDV), is regarded as one of the two most devastating diseases of poultry with the characteristics of serious disease and high flock mortality. It causes severe economic losses in domestic poultry, especially in chickens. At present, there were no effective drugs to treat this disease and the main method to control ND was vaccination. Moreover, new strains of virus resistant to chemotherapy continue to emerge, so does the need for a safe and effective vaccine. The immune adjuvant can make vaccine generate a strong immune response providing long-term protection against infection. With commonly usage of some immune adjuvants (e.g. mineral oil and aluminium hydroxide), many problems were occurred, such as side effects, strong local stimulation and carcinogenesis, together with complicated preparation, or failure to increase immunogenicity of weak antigen and so on. Botanical polysaccharides, as a new type of adjuvant or immunopotentiator, had become the hot research area because of their less side effects and no toxicity. The purpose of this research was to observe whether Chuanminshen violaceum polysaccharide (CVPS) possessed synergistical immunoenhancement, and offer the theoretical evidence for developing potential new-type adjuvant. Materials, Methods & Results: 200 three-yellow chickens at one day of age were randomly divided into four groups and reared in separated pens. On 7 days old, the average maternal serum hemaglutination inhibition (HI) antibody titer was less than 3 log2, all chickens of each group (the average body weight (BW) was 120 g) were vaccinated with ND live vaccine through nasal drip and eye-drop. At the same time, the chickens in three CVPS groups (high, medium and low doses of CVPS) were orally administered with 0.5 mL of CVPS at concentrations of 100 mg/kg BW, 50 mg/kg BW, 25 mg/kg BW respectively, once a day for fi ve successive day, in negative control group (NC), with 0.5 mL of physiological saline, once a day for fi ve successive day. On days 14, 21 and 28, the serum antibody titer, erythrocyte-C3b receptor rosette rate (E-C3bRR), erythrocyte-C3b immune complex rosette rate (E-ICRR), peripheral lymphocyte proliferation and peripheral CD4+/CD8+ ratio were measured. The results showed that the antibody titer, E-C3bRR, elimination rate of immune complex and peripheral lymphocyte proliferation in three CVPS groups and peripheral CD4+/CD8+ ratio in medium dosage of CVPS group were significantly higher (P < 0.05) than those in control group throughout the process of whole experiment almost. Discussion: The CVPS not only improved the E-C3bRR and accelerated the elimination rate of CIC, but also induced higher antibody titer, peripheral lymphocyte proliferation and peripheral CD4+ /CD8+ ratio in chickens vaccinated against ND live vaccine. This indicated that CVPS possessed immune-enhancement efficacy of ND live vaccine and might be expected as a candidate of new-type adjuvant.

Proliferação de linfócitos e apoptose de células CD5+ de bovinos infectados pelo vírus da leucose enzoótica bovina / Apoptosis of CD5+ cells and lymphocyte proliferation in bovine leukemia virus-infected dairy cows

Avaliaram-se a proliferação de linfócitos e a apoptose de células CD5+ de bovinos naturalmente infectados pelo vírus da leucose enzoótica bovina. Para tal, 100 vacas da raça Holandesa, em lactação, foram triadas quanto ao sorodiagnóstico para a leucose enzoótica bovina e o perfil hematológico, e 15 foram escolhidos e distribuídos uniformemente entre os três grupos, a saber: animais negativos, animais positivos alinfocitóticos e animais positivos e que manifestaram linfocitose persistente (LP). Para a avaliação da proliferação de linfócitos, procedeu-se ao isolamento das células mononucleares por gradiente de centrifugação, em que 2x10(6) linfócitos por mL foram plaqueados por poço e analisados por citometria de fluxo utilizando-se o fluorocromo CFSE-DA. A apoptose do sangue periférico deu-se utilizando a anexina V-FITC, e para a identificação das células CD5+, utilizaram-se anticorpos monoclonais. Ocorreu menor proliferação de linfócitos nos animais infectados e que manifestavam LP, e menor apoptose de células CD5+ do sangue periférico. Pode-se sugerir que o desenvolvimento da LP, resultante do aumento de linfócitos B, deve-se à redução do processo apoptótico das células CD5+, principal população infectada, e que a maior proliferação linfocitária pode se restringir apenas ao estádio inicial do desenvolvimento da LP.

The purpose of the present trail was to evaluate the lymphocyte proliferation and the apoptosis rates of CD5+ cells in dairy cows infected with bovine leukemia virus (BLV) with distinct lymphocyte profiles in infected animals known as alymphocytotic (AL) and persistent lymphocytosis (PL). A total of 100 Holstein cows were sera tested for bovine leukemia virus through agar gel immunodiffusion (AGID) and enzyme-linked immunosorbent-assay (ELISA). From these animals, 15 cows were selected and divided uniformly in 3 groups (negative, AL, LP). The lymphocyte proliferation was performed using flow cytometric measurement of CFSE-DA dye, where 2x10(6)/mL lymphocytes were plated per well. The apoptosis of CD5+ cells from peripheral blood was performed using the annexin V-FITC to measure the apoptosis rates and the identification of CD5+ was accessed using monoclonal antibodies. Animals from the LP group showed lower lymphocyte proliferation and also lower apoptosis rates of CD5+ cells compared with negative and AL animals. The development of PL which resulted from an increase in B cell count, is due to the decrease in the apoptosis rates of CD5+ cells, and the higher lymphocyte proliferation appears to be limited only in the initial stages of development of LP.

Proliferação de linfócitos e apoptose de células CD5+ de bovinos infectados pelo vírus da leucose enzoótica bovina / Apoptosis of CD5+ cells and lymphocyte proliferation in bovine leukemia virus-infected dairy cows

Avaliaram-se a proliferação de linfócitos e a apoptose de células CD5+ de bovinos naturalmente infectados pelo vírus da leucose enzoótica bovina. Para tal, 100 vacas da raça Holandesa, em lactação, foram triadas quanto ao sorodiagnóstico para a leucose enzoótica bovina e o perfil hematológico, e 15 foram escolhidos e distribuídos uniformemente entre os três grupos, a saber: animais negativos, animais positivos alinfocitóticos e animais positivos e que manifestaram linfocitose persistente (LP). Para a avaliação da proliferação de linfócitos, procedeu-se ao isolamento das células mononucleares por gradiente de centrifugação, em que 2x10(6) linfócitos por mL foram plaqueados por poço e analisados por citometria de fluxo utilizando-se o fluorocromo CFSE-DA. A apoptose do sangue periférico deu-se utilizando a anexina V-FITC, e para a identificação das células CD5+, utilizaram-se anticorpos monoclonais. Ocorreu menor proliferação de linfócitos nos animais infectados e que manifestavam LP, e menor apoptose de células CD5+ do sangue periférico. Pode-se sugerir que o desenvolvimento da LP, resultante do aumento de linfócitos B, deve-se à redução do processo apoptótico das células CD5+, principal população infectada, e que a maior proliferação linfocitária pode se restringir apenas ao estádio inicial do desenvolvimento da LP.(AU)

The purpose of the present trail was to evaluate the lymphocyte proliferation and the apoptosis rates of CD5+ cells in dairy cows infected with bovine leukemia virus (BLV) with distinct lymphocyte profiles in infected animals known as alymphocytotic (AL) and persistent lymphocytosis (PL). A total of 100 Holstein cows were sera tested for bovine leukemia virus through agar gel immunodiffusion (AGID) and enzyme-linked immunosorbent-assay (ELISA). From these animals, 15 cows were selected and divided uniformly in 3 groups (negative, AL, LP). The lymphocyte proliferation was performed using flow cytometric measurement of CFSE-DA dye, where 2x10(6)/mL lymphocytes were plated per well. The apoptosis of CD5+ cells from peripheral blood was performed using the annexin V-FITC to measure the apoptosis rates and the identification of CD5+ was accessed using monoclonal antibodies. Animals from the LP group showed lower lymphocyte proliferation and also lower apoptosis rates of CD5+ cells compared with negative and AL animals. The development of PL which resulted from an increase in B cell count, is due to the decrease in the apoptosis rates of CD5+ cells, and the higher lymphocyte proliferation appears to be limited only in the initial stages of development of LP.(AU)

Avaliação da proliferação de linfócitos T CD8+ por células dendríticas desafiadas com pró-oxidantes / Assesment of T CD8+ lympocytes proliferation by dendritic cells challenged with pro-oxidants

As células dendríticas são apresentadoras de antígeno mais eficazes para iniciar resposta primaria de linfocitos T. Quando internalizado o antígeno e processado gerando peptideos que serão apresentados por complexos de histocompatibilidade do tipo I em celulas dendriticas, os antigenos proteicos no citoplasma são processados pelo imunoproteassomo. Uma vez que celulas dendriticas estão nativamente expostas a uma serie de agentes estressantes incluindo os pro oxidantes, nosso objetivo neste trabalho foi examinar o efeito de pro oxidantes em celulas dendriticas para posterior avaliacao de linfocitos TCD8+... .

Dendritic cells are the most effect antigen presenting cells in starting sumary response of T lymphocytes. Once internalized, the antigen is processing generating peptides that are be presented the major histocompatibility complex type I, the cytosolic protein antigens must be processed by the imunoproteasome. Since dendritic cells are natively exposed to a variety of stress agents including pro oxidants our goal in this study was to examine the effect of pro oxidants in dendritic cell-induced TCD8 +... .