Identification and functional analysis of grouper (Epinephelus coioides) B-cell linker protein BLNK

We characterized phenotypic and functional properties of B cell lines obtained from patients with multiple myeloma to determine how well they conform to particular stages of B cell differentiation. This information is a prerequisite for using such lines as tools for studying B cell growth and the regulation thereof. Two lines, GM1312 and GM1500, expressed B1 and Ia, determinants on early B cells, but expressed little, if any, T10, a determinant expressed on plasma cells. By contrast, B1 and Ia were poorly expressed on two other lines, GM2132 and U266. T10 was expressed on GM2132 but not on U266. Using a reverse hemolytic plaque assay, we also assessed the numbers of cells actively secreting immunoglobulin (IgSCs) in such cultures to provide a functional marker of B cell differentiation. We observed consistently higher numbers of IgSCs in cultures of GM2132 than in GM1500 and GM1312. These phenotypic and functional markers were stable over several months. The data suggest that such cell lines represent early (GM1312, GM1500) and later stages (GM2132, U266) of B cell differentiation, although all lines were derived from patients with multiple myeloma.

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Abstract TP166: Age-Associated Transcriptomic Alterations in Patients With Ischemic Stroke

Stroke ◽

10.1161/str.51.suppl_1.tp166 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Gina Sykes ◽

Yusra Batool ◽

Joseph Kamtchum Tatuene ◽

Sarah Zehnder ◽

Glen C Jickling

Keyword(s):

Gene Expression ◽

Functional Analysis ◽

Ischemic Stroke ◽

Immune System ◽

B Cell ◽

Differentially Expressed Genes ◽

Hemorrhagic Transformation ◽

Differentially Expressed ◽

P Value ◽

Humoral Immune

Introduction: Immune system dysregulation occurs with age. This includes an increase in inflammation, and immunosenescence, the inability to efficiently respond to new immune challenges. These changes are evident in various diseases but have yet to be evaluated in a population with ischemic stroke. Age is an important factor in stroke, contributing to stroke risk, outcome and risk of hemorrhagic transformation. This study aimed to assess the changes that occur with age in the leukocyte gene expression of patients with ischemic stroke. Methods: Two cohorts of acute ischemic stroke patients were analyzed; cohort 1 (n=94) and cohort 2 (n=79). RNA was isolated from PAXgene tubes and processed on Affymetrix microarrays. Differentially expressed genes associated with age quartiles were identified by ANCOVA, adjusted for sex and batch. Functional analysis identified age-associated pathways. Differentially expressed genes were compared with previous non-stroke aging studies in whole blood. Results: There were 61 and 442 age-associated genes in cohorts 1 and 2 respectively (FDR-corrected p<0.05, partial correlation coefficient ≥ |0.3|). Nineteen genes, including CR2, CCR6 and CXCR5 , were found in common and decreased with age among both cohorts (max-log10(p value) = 17). Functional analysis of the 61 and 442 genes revealed with advancing age there is a change in the humoral immune system, including antibody production and B cell proliferation. When compared to aging gene expression studies in controls, 52% of age-associated genes in cohort 1 and 31% of cohort 2 age-associated genes overlapped with those found in controls, and 16 of the 19 common genes to both cohorts overlapped in controls (max-log10(p value) = 15). Conclusion: In patients with acute stroke there is a change in leukocyte gene expression with advancing age. Changes included a shift in humoral immune response with a potentially impaired B cell response. While many of the age-associated alterations in gene expression present in stroke are similar to non-stroke controls, these changes warrant further investigation for their impact on stroke outcome and risk.

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