Search results for "amer"
showing 10 items of 2105 documents
Isolation of CD4+ T cells from murine lungs: a method to analyze ongoing immune responses in the lung.
2007
The regulation of the cellular immune response in lung diseases is not yet fully understood. Isolating different subsets of immune cells directly from the lung is therefore an indispensable method of gaining detailed knowledge on the function of these cells in this organ. This protocol describes a method of isolating and magnetically labeling CD4+ lung T cells, which are then loaded and retained on the column while all other cells run through it (positive selection). The yield of this isolation is approximately 5 x 10(5) to 1.5 x 10(6) CD4+ cells from a murine lung. These cells can be further investigated by several methods such as flow cytometry, western blot analysis, RT-PCR, immunostaini…
Rapid identification and sorting of viable virus-reactive CD4+ and CD8+ T cells based on antigen-triggered CD137 expression
2008
Abstract Current methods for the detection and isolation of antigen-specific CD4 + and CD8 + T cells require the availability of peptide/MHC multimers or are restricted to cells that produce cytokines after antigen contact. Here we show that de novo cell surface expression of the TNF-receptor family member CD137 (4-1BB) identifies recently activated, but not resting, human CD4 + and CD8 + memory T cells. Maximum CD137 expression level is uniformly observed in both T-cell subsets at 24h after stimulation with antigen. In experiments with CMV and EBV-reactive T cells, we confirmed the specificity of CD137 expression by co-staining with peptide/HLA tetramers. Substantial proportions of CD137 +…
Increasing functional avidity of TCR-redirected T cells by removing defined N-glycosylation sites in the TCR constant domain
2009
Adoptive transfer of T lymphocytes transduced with a T cell receptor (TCR) to impart tumor reactivity has been reported as a potential strategy to redirect immune responses to target cancer cells (Schumacher, T.N. 2002. Nat. Rev. Immunol. 2:512-519). However, the affinity of most TCRs specific for shared tumor antigens that can be isolated is usually low. Thus, strategies to increase the affinity of TCRs or the functional avidity of TCR-transduced T cells might be therapeutically beneficial. Because glycosylation affects the flexibility, movement, and interactions of surface molecules, we tested if selectively removing conserved N-glycoslyation sites in the constant regions of TCR alpha or …
Optimized Protocol for the Detection of Multifunctional Epitope-Specific CD4+ T Cells Combining MHC-II Tetramer and Intracellular Cytokine Staining T…
2019
Analysis of multifunctional CD4+ T cells is fundamental for characterizing the immune responses to vaccination or infection. Major histocompatibility complex (MHC)/peptide tetramers represent a powerful technology for the detection of antigen-specific T cells by specific binding to their T-cell receptor, and their combination with functional assays is fundamental for characterizing the antigen-specific immune response. Here we optimized a protocol for the detection of multiple intracellular cytokines within epitope-specific CD4+ T cells identified by the MHC class II tetramer technology. The optimal procedure for assessing the functional activity of tetramer-binding CD4+ T cells was based o…
2 Isolation of T Cells and Establishment of T-cell Lines and Clones
1998
Publisher Summary This chapter elaborates the isolation of T cells and the establishment of T-cell lines and clones. The study of human T cells is best performed using purified cells because the presence of other cell types may have indirect effects on T-cell function. For any kind of functional assay on T-cell specificity, antigen-presenting cells are necessary. T cells appear to play a major role in the development, maintenance, and also resolution of these forms of bacteria-associated arthritides. The E-rosetting technique describes a procedure for separating T cells and non-T cells from a population of MNCs. This method is based on the ability of human T cells to bind to sheep erthrocyt…
B7-1 and B7-2 act differentially in the induction of a T cell response: their impact for a HLA-matched and HLA-mismatched anti-tumor immunotherapy.
2005
The efficacy of T cell-based immunotherapy is primarily due to efficient cellular activation that requires the engagement of 2 separate signals, i.e., via the T cell receptor complex and via co-stimulatory molecules the prototype of which is CD28. In cellular activation, the CD28 ligands B7-1 (CD80) and B7-2 (CD86) are thought to play nearly identical roles in T cell activation. We monitored the T cell response upon co-culture with HLA Class I-matched and mismatched renal carcinoma cells, respectively, that express different levels of B7-1 and B7-2, respectively. In a HLA Class I-mismatched co-culture, T cell proliferation, IFN-γ and GM-CSF secretion equally depend on the levels of B7-1 and…
How credit ratings affect sovereign credit risk: cross-border evidence in Latin American emerging markets
2017
This article builds upon previous literature by providing a better understanding of how contagion changes in bordering sovereign CDS emerging markets resulting from credit rating events. To that end, we follow the novel GVAR methodology using data from six Latin American emerging countries during an extensive sample period from 2004 to 2014. Our findings show evidence for the existence of significant and asymmetric cross-border effects. In particular, a competition effect is observed before the event occurs, indicating that non-event countries suffer (benefit) from upgrades (downgrades) in Brazil, Mexico and Chile (in Argentina and Brazil). In contrast, an imitation effect is observed after…
The Affective Turn and Sacred Femininity in African American Women's Literature
2017
Després del llarg viatge a través de l’Atlàntic a bord dels vaixells esclavistes, els africans van veure’s obligats a enfrontar-se a la seua completa alienació física, social i també espiritual en les terres de l’anomenat ‘Nou Món’. La seua anterior concepció de l’univers com a un lloc on poden exisitir-hi un ventall il·limitat de déus es va veure estroncat per la imposició social d’un univers on l’esclau va perdre tant el seu sentit d’espai com de temps. Així doncs, la evolució històrica del poble afroamericà s’esmerça en conrear una concepció sagrada del seu entorn des del mateix moment en que arriben a terres americanes. Aquesta obligada gestació espiritual els commina a acollir i, alhor…
La presencia negra en el Perú
2021
LOS ESCALVOS NEGROS AFRICXANOS HAN SIDO LOS PRINCIPALES PROTAGONISTAS SILENCIOSOS Y NO VISIBILIZADOS EN LA VIDA SOCIAL, ECONOMICA Y CULTURAL EN LA HISTORIA DEL PERU. SIN EMBARGO, A PESAR DE SU POSICION SUBORDINADA, DISCRIMINADA Y SEGREGADA, LOS AFROAMERICANOS TUVIERON LA CAPACIDAD DE INTERACTUAR EN LA ECONOMIA, LAS ARTES, LA RELIGION PERUANAS NO OCASIONALMENTE, SINO DE FORMA HABITAUL, COTIDIANA Y PERMANENTE.
Mixed Messages and Conflicting Loyalties: Reevaluating the Californio Community of San Diego during the Mexican-American War (1846-1848)
2014
An important element in the identity constructs of both sides of the border, the Mexican-American War of 1846-1848 is often depicted exclusively through a nationalist perspective, with strong associations of victor and vanquished. This article explores how the Californio community in San Diego was divided during this conflict with active support given to both nations involved. While such a division can be examined and understood in a local context, it poses problems for the national discourses surrounding the acquisition of California by the United States. We wish then to focus on this fratricidal rift that has largely disappeared from the public remembrance of this period, including its ef…