Interferon-α mediating the functional damage of CD56dimCD57+natural killer cells in peripheral blood of systemic lupus erythematosuss / 北京大学学报(医学版)

OBJECTIVE@#To investigate the regulatory effect of interferon-α (IFN-α) on the apoptosis and killing function of CD56dimCD57+ natural killer (NK) cells in systemic lupus erythematosus (SLE) patients, and to explore the specific mechanism.@*METHODS@#A total of sixty-four newly treated SLE patients and sixteen healthy controls (HC) enrolled in the Second Hospital of Dalian Medical University were selected as the research subjects. And the gene expression levels of molecules related to NK cell-killing function were detected by real-time quantitative polymerase chain reaction. CD56dimCD57+ NK cells were co-cultured with the K562 cells, and the apoptotic K562 cells were labeled with Annexin-Ⅴ and 7-amino-actinomycin D. Peripheral blood mononuclear cells were treated with 20, 40, and 80 μmol/L hydrogen peroxide (H2O2), and treated without H2O2 as control, the expression level of perforin (PRF) was detected by flow cytometry. The concentration of IFN-α in serum was determined by enzyme linked immunosorbent assay. The expression levels of IFN-α receptors (IFNAR) on the surface of CD56dimCD57+ NK cells were detected by flow cytometry, and were represented by mean fluorescence intensity (MFI). CD56dimCD57+ NK cells were treated with 1 000 U/mL IFN-α for 24, 48 and 72 h, and no IFN-α treatment was used as the control, the apoptosis and the expression levels of mitochondrial reactive oxygen species (mtROS) were measured by flow cytometry and represented by MFI.@*RESULTS@#Compared with HC(n=3), the expression levels of PRF1 gene in peripheral blood NK cells of the SLE patients (n=3) were decreased (1.24±0.41 vs. 0.57±0.12, P=0.05). Compared with HC(n=5), the ability of peripheral blood CD56dimCD57+ NK cells in the SLE patients (n=5) to kill K562 cells was significantly decreased (58.61%±10.60% vs. 36.74%±6.27%, P < 0.01). Compared with the control (n=5, 97.51%±1.67%), different concentrations of H2O2 treatment significantly down-regulated the PRF expression levels of CD56dimCD57+ NK cells in a dose-dependent manner, the 20 μmol/L H2O2 PRF was 83.23%±8.48% (n=5, P < 0.05), the 40 μmol/L H2O2 PRF was 79.53%±8.56% (n=5, P < 0.01), the 80 μmol/L H2O2 PRF was 76.67%±7.16% (n=5, P < 0.01). Compared to HC (n=16), the serum IFN-α levels were significantly increased in the SLE patients (n=45) with moderate to high systemic lupus erythematosus disease activity index (SLEDAI≥10) [(55.07±50.36) ng/L vs. (328.2±276.3) ng/L, P < 0.001]. Meanwhile, compared with HC (n=6), IFNAR1 expression in peripheral blood CD56dimCD57+ NK cells of the SLE patients (n=6) were increased (MFI: 292.7±91.9 vs. 483.2±160.3, P < 0.05), and compared with HC (n=6), IFNAR2 expression in peripheral blood CD56dimCD57+ NK cells of the SLE patients (n=7) were increased (MFI: 643.5±113.7 vs. 919.0±246.9, P < 0.05). Compared with control (n=6), the stimulation of IFN-α (n=6) significantly promoted the apoptosis of CD56dimCD57+ NK cells (20.48%±7.01% vs. 37.82%±5.84%, P < 0.05). In addition, compared with the control (n=4, MFI: 1 049±174.5), stimulation of CD56dimCD57+ NK cells with IFN-α at different times significantly promoted the production of mtROS in a time-dependent manner, 48 h MFI was 3 437±1 472 (n=4, P < 0.05), 72 h MFI was 6 495±1 089 (n=4, P < 0.000 1), but there was no significant difference at 24 h of stimulation.@*CONCLUSION@#High serum IFN-α level in SLE patients may induce apoptosis by promoting mtROS production and inhibit perforin expression, which can down-regulate CD56dimCD57+ NK killing function.

Aconite aqueous extract inhibits the growth of hepatocellular carcinoma through CCL2-dependent enhancement of natural killer cell infiltration / 中西医结合学报

OBJECTIVE@#Aconite is a traditional Chinese herbal medicine that has been found to inhibit the development of liver cancer; however, its exact molecular mechanisms in this process remain unclear. This study explores how aconite aqueous extract (AAE) inhibits hepatocellular carcinoma (HCC).@*METHODS@#An in vivo mouse model of subcutaneous liver cancer was established. After AAE treatment, immunohistochemistry (IHC) was used to determine the effect of AAE on natural killer (NK) cells. Subsequently, C57BL/6 mice were used to establish the subcutaneous tumor model, and a group of these mice were treated with anti-PK163 antibody to remove NK cells, which was verified by flow cytometry and IHC. The effect of AAE on the proliferation of HCC cells in vitro was determined using cell counting kit-8. The effect of AAE on chemokine production in HCC cells was measured using real-time quantitative polymerase chain reaction and an enzyme-linked immunosorbent assay. The effect of AAE on the migration of NK cells was determined using a transwell assay. Finally, the molecular mechanism was investigated using the Western blotting method.@*RESULTS@#We demonstrated that the ability of AAE to induce overexpression of the cytokine C-C motif chemokine ligand 2 (CCL2) in HCC cells is fundamental to the infiltration of NK cells into the tumor bed. Mechanistically, we found that the upregulation of CCL2 was achieved by the activation of c-Jun N-terminal kinase but not extracellular regulated protein kinase or p38.@*CONCLUSION@#Our findings suggest that AAE can be used as an effective immune adjuvant to enhance antitumor immunity by increasing NK cell infiltration into tumors, which could help to improve the efficacy of HCC treatments. Please cite this article as: Yang KD, Zhang X, Shao MC, Wang LN. Aconite aqueous extract inhibits the growth of hepatocellular carcinoma through CCL2-dependent enhancement of natural killer cell infiltration. J Integr Med. 2023; 21(6): 575-583.

Progress in Chimeric Antigen Receptor-Modified Natural Killer Cells for Multiple Myeloma / 中国医学科学院学报

Although the development of novel drugs has significantly improved the survival of patients with multiple myeloma (MM) over the past decades,the lack of effective therapeutic options for relapsed and refractory MM results in poor prognosis.The chimeric antigen receptor (CAR) T-cell therapy has achieved considerable progress in relapsed and refractory MM.Nevertheless,this therapy still has limitations such as cytokine release syndrome,neurotoxicity,and off-target effects.Natural killer (NK) cells,as a critical component of the innate immune system,play an essential role in tumor immunosurveillance.Therefore,CAR-modified NK (CAR-NK) cells are put forward as a therapeutic option for MM.The available studies have suggested that multiple targets can be used as specific therapeutic targets for CAR-NK cell therapy and confirmed their antitumor effects in MM cell lines and animal models.This review summarizes the anti-tumor mechanisms,biological characteristics,and dysfunction of NK cells in the MM tumor microenvironment,as well as the basic and clinical research progress of CAR-NK cells in treating MM.

Understanding endometriosis from an immunomicroenvironmental perspective / 中华医学杂志(英文版)

Endometriosis, a heterogeneous, inflammatory, and estrogen-dependent gynecological disease defined by the presence and growth of endometrial tissues outside the lining of the uterus, affects approximately 5-10% of reproductive-age women, causing chronic pelvic pain and reduced fertility. Although the etiology of endometriosis is still elusive, emerging evidence supports the idea that immune dysregulation can promote the survival and growth of retrograde endometrial debris. Peritoneal macrophages and natural killer (NK) cells exhibit deficient cytotoxicity in the endometriotic microenvironment, leading to inefficient eradication of refluxed endometrial fragments. In addition, the imbalance of T-cell subtypes results in aberrant cytokine production and chronic inflammation, which contribute to endometriosis development. Although it remains uncertain whether immune dysregulation represents an initial cause or merely a secondary enhancer of endometriosis, therapies targeting altered immune pathways exhibit satisfactory effects in preventing disease onset and progression. Here, we summarize the phenotypic and functional alterations of immune cells in the endometriotic microenvironment, focusing on their interactions with microbiota and endocrine and nervous systems, and how these interactions contribute to the etiology and symptomology of endometriosis.

Research progress in leveraging biomaterials for enhancing NK cell immunotherapy / 浙江大学学报·医学版

NK cell immunotherapy is a promising antitumor therapeutic modality after the development of T cell immunotherapy. Structural modification of NK cells with biomaterials may provide a precise, efficient, and low-cost strategy to enhance NK cell immunotherapy. The biomaterial modification of NK cells can be divided into two strategies: surface engineering with biomaterials and intracellular modification. The surface engineering strategies include hydrophobic interaction of lipids, receptor-ligand interaction between membrane proteins, covalent binding to amino acid residues, click reaction and electrostatic interaction. The intracellular modification strategies are based on manipulation by nanotechnology using membranous materials from various sources of NK cells (such as exosome, vesicle and cytomembranes). Finally, the biomaterials-based strategies regulate the recruitment, recognition and cytotoxicity of NK cells in the solid tumor site in situ to boost the activity of NK cells in the tumor. This article reviews the recent research progress in enhancing NK cell therapy based on biomaterial modification, to provide a reference for further researches on engineering NK cell therapy with biomaterials.

Can natural killer cell activity help screen patients requiring a biopsy for the diagnosis of prostate cancer?

ABSTRACT Purpose To evaluate the usefulness of natural killer cell activity (NKA) in diagnosing prostate cancer (PC). Materials and Methods The medical records of patients who underwent transrectal prostate biopsy (TRBx) at Korea University Ansan Hospital between May 2017 and December 2017 were retrospectively reviewed. NKA levels were measured using NK Vue® Tubes (ATgen, Sungnam, Korea). All blood samples were obtained at 8 AM on the day of biopsy. Patients with other malignancies, chronic inflammatory conditions, high prostate-specific antigen (PSA) level (>20ng/mL), or history of taking 5-alpha-reductase inhibitor or testosterone replacement therapy were excluded. Results A total of 102 patients who underwent TRBx for PC diagnosis were enrolled. Among them, 50 were diagnosed with PC. Significant differences in age and NKA level were observed between the PC and no-PC groups. Receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off of NKA level for the prediction of PC was 500pg/dL, with a sensitivity of 68.0% and a specificity of 73.1%. In addition, NKA level (0.630) had the greatest area under the ROC curve compared to those for the ratio of total PSA to free PSA (0.597) and PSA density (0.578). Conclusions The results of this pilot study revealed that low NKA and high PSA levels were likely to be associated with a positive TRBx outcome. NKA detection was easy and improved the diagnostic accuracy of PC.

Leucemia agresiva de células natural killer en un paciente pediátrico / Agressive NK-cell leukemia in a pediatric patient

Resumen Introducción: Las neoplasias de células natural killer (NK) son poco frecuentes y representan <5% de todas las neoplasias linfoides. Comprometen diferentes entidades clínicas, como la leucemia de células NK, que es una neoplasia hematológica altamente agresiva con un pronóstico precario, que se presenta en hombres jóvenes y se observa con mayor frecuencia en ascendencia asiática. El virus de Epstein-Barr (VEB) parece estar relacionado con la patogenia de esta leucemia. Caso clínico: Se presenta el caso de un paciente de sexo masculino de 1 año y 7 meses de edad, quien inició su padecimiento con síndrome anémico, febril, infiltrativo e hiperleucocitosis. En el aspirado de médula ósea se detectaron blastos de morfología L2 (96%), inmunofenotipo CD56 (80.87%) y desoxinucleotidil transferasa terminal (84.11%). En la biopsia de médula ósea se identificó CD2+ membranoso, CD3+ citoplásmico y CD56+ membranoso; la serología para VEB fue positiva. El paciente recibió dos esquemas diferentes de quimioterapia basados en metotrexato, ifosfamida, etopósido, dexametasona y L-asparaginasa, y se documentó remisión parcial. Actualmente, se encuentra vivo con la enfermedad. Conclusiones: La leucemia de células NK es rara en adultos jóvenes, pero aún más en pacientes en edad pediátrica. Además, es de muy difícil tratamiento, ya que solo se cuenta con algunos reportes de casos, la sobrevida es de semanas a meses y las oportunidades de tratamiento se limitan. Recientemente, se ha evidenciado la utilidad del trasplante de médula ósea alogénico o células de cordón umbilical, y se ha logrado una sobrevida a 2 años. Las posibilidades terapéuticas en estos pacientes se encuentran en estudio. Se espera lograr en un futuro cercano la remisión completa y sobrevida a 5 años.

Abstract Background: Natural killer (NK) cell neoplasms are rare and represent <5% of all lymphoid neoplasms. They involve different clinical entities, of which one is NK cell leukemia, a highly aggressive hematologic neoplasm with poor prognosis that presents in young men and is more frequently seen in Asian descent. Epstein-Barr virus (EBV) seems to be related to the pathogenesis. Case report: A male patient of 1 year and 7 months of age, who began his condition with anemic, febrile, infiltrative syndrome and hyperleukocytosis is described. Bone marrow aspirate showed L2 morphology blasts (96%), CD56 (80.87%) and terminal deoxynucleotidyl transferase (84.11%) immunophenotype. Bone marrow biopsy showed membranous CD2+, cytoplasmic CD3+ and membranous CD56+; serology positive to EBV. The patient received two different chemotherapy schemes based on methotrexate, ifosfamide, etoposide, dexamethasone and L-asparaginase, which resulted in partial remission. Currently, the patient lives with the disease. Conclusions: NK cells leukemia is rare in young adults, but even more in pediatric patients, for which it is very difficult to treat because only a few cases have been reported in the literature, the survival varies from weeks to months and the chances of treatment are limited. Recently, the usefulness of allogeneic bone marrow transplantation or umbilical cord cells has been demonstrated, achieving a 2-year survival. The therapeutic possibilities in these patients are under study. In the near future, we hope to achieve the complete remission of the disease and a 5-year survival.

Novel identification and characterisation of Transient receptor potential melastatin 3 ion channels on Natural Killer cells and B lymphocytes: effects on cell signalling in Chronic fatigue syndrome/Myalgic encephalomyelitis patients

BACKGROUND: Transient receptor potential melastatin 3 (TRPM3) cation channels are ubiquitously expressed by multiple cells and have an important regulatory role in calcium-dependent cell signalling to help maintain cellular homeostasis. TRPM3 protein expression has yet to be determined on Natural Killer (NK) cells and B lymphocytes. Multiple single nucleotide polymorphisms have been reported in TRPM3 genes from isolated peripheral blood mononuclear cells, NK and B cells in Chronic fatigue syndrome/Myalgic encephalomyelitis (CFS/ME) patients and have been proposed to correlate with illness presentation. The object of the study was to assess TRPM3 surface expression on NK and B lymphocytes from healthy controls, followed by a comparative investigation examining TRPM3 surface expression, and cytoplasmic and mitochondrial calcium influx in CD19+ B cells, CD56bnght and CD56dim cell populations from CFS/ME patients. RESULTS: TRPM3 cell surface expression was identified for NK and B lymphocytes in healthy controls (CD56bright TRPM3 35.72 % ± 7.37; CD56dim 5.74 % ± 2.00; B lymphocytes 2.05 % ± 0.19, respectively). There was a significant reduction of TRPM3 surface expression on CD19+ B cells (1.56 ± 0.191) and CD56bright NK cells (17.37 % ± 5.34) in CFS/ME compared with healthy controls. Anti-CD21 and anti-IgM conjugated biotin was cross-linked with streptavidin,and subsequently treatment with thapsigargin. This showed a significant reduction in cytoplasmic calcium ion concentration in CD19+ B lymphocytes. CD56bright NK cells also had a significant decrease in cytoplasmic calcium in the presence of 2-APB and thapsigargin in CFS/ME patients. CONCLUSIONS: The results from this preliminary investigation identify, for the first time, TRPM3 surface expression on both NK and B lymphocytes in healthy controls. We also report for the first time, significant reduction in TRPM3 cell surface expression in NK and B lymphocytes, as well as decreased intracellular calcium within specific conditions in CFS/ME patients. This warrants further examination of these pathways to elucidate whether TRPM3 and impaired calcium mobilisation has a role in CFS/ME.

O exercício físico e as células natural killer: uma revisão sistemática da literatura / Physical exercise and the natural killer cells: a systematic review

A célula natural killer, linfócito atuante no sistema inato, tem como funçãodestruir células tumorais ou infectadas por vírus. Essas células podem sofrer alterações com o exercício físico,qualitativa e quantitativamente, fato este que não é bem estabelecido na literatura. A presente revisão tem porobjetivo descrever a influência do exercício físico na contagem e função das células natural killer (NK Foi realizadauma busca em bases de dados internacionais, na qual 916 estudos originais com seres humanos relacionadosao exercício físico e às células NK foram encontrados, porém apenas 21 estudos atenderam a proposta doestudo. Observar-se na literatura que não há um consenso sobre a influência do exercício sobre a contageme a função das células NK. Essas diferenças nas respostas podem ser explicadas pelos diferentes protocolos deexercícios físicos, bem como pelos diferentes métodos de contagem dessas células. A intensidade e a duraçãodo exercício físico, em uma ampla margem, podem influenciar quantitativa e qualitativamente as células naturalkiller. Contudo, as características do estímulo físico ofertado permeiam as respostas das células natural killer.

The natural killer cell, lymphocyte active in the innate system, serves todestroy tumor cells or virus-infected. These cells are subject to change with physical exercise, qualitatively andquantitatively, this fact is not well established in the literature. The aim of this review is to describe the influenceof physical exercise in the count and function of natural killer cells. We performed a search in internationaldatabases, in which 916 original studies in humans related physical exercise and natural killer cells were found,but only 21 studies met the study proposal. It can be seen in the literature that there is no consensus on theinfluence of exercise on the count and function of natural killer cells. These differences in the responses canbe explained by the different protocols of physical exercise. The intensity and duration of exercise, may affectquantitative and qualitative natural killer cells. However, the features of the physical stimulus offered permeatethe responses of natural killer cells.

Expression of TLR2 and TLR4 in lesions of patients with tegumentary american leishmaniasis / Expressão de TLR2 e TLR4 em lesões de pacientes com leishmaniose tegumentar americana

OBJECTIVES: The aim of this study was to describe the pattern of expression of Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) in skin biopsies of patients with American tegumentary leishmaniasis (ATL) caused by Leishmania braziliensis. METHODS: This prospective study evaluated 12 patients with ATL caused by Leishmania braziliensis confirmed by polymerase chain reaction. Immunohistochemistry was performed to determine the expression of TLR2 and TLR4. The number of NK cells, dendritic cells and macrophages in the tissue were calculated. The cytokine expression was determined using the anti-TNF-α, anti-IFN-Γ, anti-IL-1 and anti-IL-6. Double immunostaining reactions were used to determine the cell expressing TLR2 and TLR4. RESULTS: The numbers of cells expressing TLR2 and TLR4 were 145.48 ± 82.46 cell/mm² and 3.26 ± 4.11 cell/mm² respectively (p < 0.05). There was no correlation of TLR2 and TLR4 with the amount of cytokines and the number of NK cells, dendritic cells or macrophages. The double immunostaining revealed that TLR2 was expressed by macrophages. CONCLUSION: In human cutaneous leishmaniasis caused by Leishmania braziliensis, TLR2 is the most common TLR expressed during active disease, mainly by macrophages although without correlation with the amount of cytokines and number of cells.

OBJETIVOS: O objetivo deste estudo foi descrever o padrão de expressão dos receptores toll-like 2 e 4 (TLR2 e TLR4) em biópsias de pele de pacientes com leishmaniose tegumentar americana (LTA). MÉTODOS: Este estudo prospectivo avaliou 12 pacientes com LTA causada por Leishmania braziliensis confirmada por reação em cadeia da polimerase. Imunohistoquímica foi realizada para determinar a expressão de TLR2 e TLR4. O número de células NK, células dendríticas e macrófagos foi calculado no tecido. A expressão de citocinas foi determinada usando anti-TNF-α, anti-IFN-Γ, anti-IL-1 e anti-IL-6. Dupla marcação foi usada para determinar a célula responsável pela expressão de TLR2 e TLR4. RESULTADOS: O número de células expressando TLR2 e TLR4 foi 145.48±82.46 cell/mm² e 3.26 ± 4.11 cell/mm² respectivamente (p < 0.05). Não houve correlação entre a quantidade de expressão de TLR2 e TLR4 com a quantidade de citocinas e o número de células NK, macrófagos e células dendríticas. A dupla marcação revelou que o TLR2 é expresso por macrófagos. CONCLUSÃO: Na LTA causada por Leishmania braziliensis, TLR2 é o TLR mais comum na doença ativa, principalmente por macrófagos sem correlação com a quantidade de citocinas e outras células.

[Effects of a single incremental exhausting exercise on circulating numbers of lymplocyes subsets in male athletes]

Intense exercise activity has been known as one of the immune system suppressor. The purpose of the present study was to examine the effect of a single incremental exhausting exercise on circulting numbers of T cell and NK cell subsets in healthy young male athletes. Twenty male subjects with mean age 22/4 +/- 1/8 [SD] yr, mean Vo2max 41/7 +/- 7/1 [SD] ml/kg/min and mean BMI 23 +/- 1/87 [SD] kg/m2 were divided randomly into two control group [n=10] and experimental group [n=10]. The experimental subjects performed a standard bicycle ergometer test whereas the control subjects did not participate in any exercise activity. Blood samples were collected pre-, immediately post-, and 2 hours post-exercise. The T and and NK lymphocyte subsets were analyzed with flow cytometry. There was a significant increase in the percentage of T [CD8] and NK [CD16/56] and a significant decrase in the percentage of T [CD4] and the ratio of CD4/CD8 from pre-, to immediately post-exercise [p<0.05]. Both changes returned to pre-exercise values at 2 hours post-exercise. Addtionally, no significant changes was found in the percentage of CD56 and CD16 [NK] cells following exercise Findings of this study indicate a single intense and short-term training session caused transient and temporary changes in circulating lymphocytes counts. Thus, it is reommonded that the interval between training designed in a way that the immune system reverts back to its original status

Impaired responses of leukemic dendritic cells derived from a human myeloid cell line to LPS stimulation

Several myeloid leukemia-derived cells have been reported to possess the ability to differentiate into dendritic cells (DC). MUTZ-3, a myeloid leukemia cell line, responds to GM-CSF, IL-4 and TNF-alpha, and acquires a phenotype similar to immature monocyte-derived DC (MoDC). In the present study, MUTZ-3-derived DC (MuDC) showed high level expression of HLA class II molecules, CD80 and CD86, and were able to function as potent antigen presenting cells as previously reported. Interestingly, MuDC maturation was induced by CD40-mediated stimulation, but not by LPS stimulation. We analyzed CCR1, CCR7 and Toll-like receptor (TLR) expressions in MuDC, and measured IL-10 and IL-12 production after maturation stimuli. Although MuDC expressed the mRNA for TLR4, a major component of the LPS receptor system, they did not show an enhanced level of CCR7 or cytokine production after LPS stimulation. In contrast, they responded to CD40 stimulation, which resulted in increased levels of CD83, CD86 and CCR7. Moreover, while LPSstimulated MoDC could potently stimulate NK cells in a DC-NK cell co-culture, LPS-stimulated MuDC failed to stimulate primary NK cells. Taken together, our findings suggest that, although MuDC express TLR4, unlike TNF-alpha and IL-1beta, LPS does not stimulate MuDC to acquire mature phenotypes, and they may have impaired activity to initiate innate immune response.

Determination of laboratory reference ranges for lymphocyte immunophenotype subsets in healthy adult Japanese using flow cytometry.

This study represents a comprehensive evaluation of normative values for lymphocyte immunophenotype subsets using flow cytometry techniques in a Japanese population. Lymphocyte reference ranges were determined for percentage and absolute count of T, B, and NK cells in healthy adult Japanese using an extensive two-color immunophenotyping panel and consistently applied quality control methodology. Reference values were also determined for activation markers on CD3+ lymphocytes CD3+/CD25+, CD3+/CD38+ and CD3+/HLA-DR+. Differences in age and gender were observed for specific lymphocyte subsets. Comparison of the Japanese study with a Thai multi-center study that used similar methodology also demonstrated ethnic differences in lymphocyte reference ranges. The results in this study strongly suggest that reference values derived from studies in one population may not be applied to another population even when similar protocols for reagents, instruments and procedures are used although such studies do appear useful for epidemiological comparisons.

External quality control study of lymphocyte subset tests in Japan.

We have evaluated external quality assurance of lymphocytes subset tests in Japan. The data suggest: 1) Values of lymphocyte subsets were variable at each medical laboratory in Japan. 2) Value of CD3 did not varied so much, but that of CD 19/20 or NK marker was widely varied. 3) Values of CD4 and CD8 varied in small extension. 4) CV of values was relatively low when analysis was carried out in commercial laboratories or when antibodies and instrument of Ortho-Clinical Diagnostics were used. 5) In some cases, CV was also relatively low if number of cell washing times was low or if self made lytic agents were used for cell lysing.

The role of natural killer cells in the early period of infection in murine cutaneous leishmaniasis

In order to study the role of natural killer (NK) cells during the early period of Leishmania infection, BALB/c mice were selectively and permanently depleted of NK cells by injection with 90Sr and subsequently infected with Leishmania (Leishmania) amazonensis (HSJD-1 strain). 90Sr is known to selectively deplete NK cells, leaving an intact T- and B-cell compartment and preserving the ability to produce both interferon alpha and IL-2. This method of depletion has advantages when compared with depletion using anti-NK cell monoclonal antibodies because the effect is permanent and neither activates complement nor provokes massive cell death. In the present study, after one month of treatment with 90Sr, the depletion of NK cells was shown by a more than ten-fold reduction in the cytotoxic activity of these cells: 2 x 106 spleen cells from NK-depleted animals were required to reach the same specific lysis of target cells effected by 0.15 x 106 spleen cells from normal control animals. The histopathology of the skin lesion at 7 days after Leishmania infection showed more parasites in the NK cell-depleted group. This observation further strengthens a direct role of NK cells during the early period of Leishmania infection

Metodos de cuantificacion de la actividad citotoxica natural: un estudio comparativo / Quantitation methods of the natural killer cell activity: a comparative study

Las unidades liticas constituyen en la actualidad una de las formas mas usadas de cuantificacion de la actividad citotoxica natural. En el presente trabajo se utilizaron represiones lineales y no lineales propuestas en la literatura para el calculo de estas, con el objetivo de comparar el comportamiento de dichos modelos. Fueron ajustadas ecuaciones de regresion lineal de: a) por ciento de cromo desprendido vs la cantidad de celulas electoras, b) por ciento de cromo desprendido vs el logaritmo de la cantidad de celulas efectoras y c) arcoseno de la raiz cuadrada de la proporcion de cromo desprendido vs la cantidad de celulas efectoras; asi como una ecuacion no lineal de la forma Y = A* [1/exp(/k*x)], donde Y es el por ciento de Cr desprendido. A la lisis maxima experimental, x la proporcion efectoras-diana y K la pendiente de la recta que se obtiene al plotear In(A-Y) vx x. Los modelos fueron comparados desde un punto de vista estadistico, se utilizaron indicadores de bondad de ajuste, prueba de significacion de la regresion para las ecuaciones lineales y porcentajes de variacion explicados por los modelos, asi como desde un punto de vista biologico a partir de su adecuacion al fenomeno en estudio. El modelo de regresion no lineal usuado mostro ventajas apreciables en este sentido