Kinetics of the pleiotropic effect of interleukin 4 on the surface properties of human B-lymphoma cells

CD58 Immunobiology at a Glance

The glycoprotein CD58, also known as lymphocyte-function antigen 3 (LFA-3), is a costimulatory receptor distributed on a broad range of human tissue cells. Its natural ligand CD2 is primarily expressed on the surface of T/NK cells. The CD2-CD58 interaction is an important component of the immunological synapse (IS) that induces activation and proliferation of T/NK cells and triggers a series of intracellular signaling in T/NK cells and target cells, respectively, in addition to promoting cell adhesion and recognition. Furthermore, a soluble form of CD58 (sCD58) is also present in cellular supernatant in vitro and in local tissues in vivo. The sCD58 is involved in T/NK cell-mediated immune responses as an immunosuppressive factor by affecting CD2-CD58 interaction. Altered accumulation of sCD58 may lead to immunosuppression of T/NK cells in the tumor microenvironment, allowing sCD58 as a novel immunotherapeutic target. Recently, the crucial roles of costimulatory molecule CD58 in immunomodulation seem to be reattracting the interests of investigators. In particular, the CD2-CD58 interaction is involved in the regulation of antiviral responses, inflammatory responses in autoimmune diseases, immune rejection of transplantation, and immune evasion of tumor cells. In this review, we provide a comprehensive summary of CD58 immunobiology.

Characterisation and in silico analysis of interleukin-4 cDNA of nilgai (Boselaphus tragocamelus) and Indian buffalo (Bubalus bubalis)

Interleukin-4 (IL-4) produced from Th2 cells modulates both innate and adaptive immune responses. It is a common belief that wild animals possess better immunity against diseases than domestic and laboratory animals; however, the immune system of wild animals is not fully explored yet. Therefore, a comparative study was designed to explore the wildlife immunity through characterisation of IL-4 cDNA of nilgai, a wild ruminant, and Indian buffalo, a domestic ruminant. Total RNA was extracted from peripheral blood mononuclear cells of nilgai and Indian buffalo and reverse transcribed into cDNA. Respective cDNA was further cloned and sequenced. Sequences were analysed in silico and compared with their homologues available at GenBank. The deduced 135 amino acid protein of nilgai IL-4 is 95.6% similar to that of Indian buffalo. N-linked glycosylation sequence, leader sequence, Cysteine residues in the signal peptide region, and 3′ UTR of IL-4 were found to be conserved across species. Six nonsynonymous nucleotide substitutions were found in Indian buffalo compared to nilgai amino acid sequence. Tertiary structure of this protein in both species was modeled, and it was found that this protein falls under 4-helical cytokines superfamily and short chain cytokine family. Phylogenetic analysis revealed a single cluster of ruminants including both nilgai and Indian buffalo that was placed distinct from other nonruminant mammals.

Chronic lymphocytic leukemia cell CD38 expression and inducible nitric oxide synthase expression are associated with serum IL-4 levels

B cell chronic lymphocytic leukemia (CLL) CD38 expression is variable and may predict outcome. Inducible nitric oxide synthase (NOS2) expression regulates CLL cell apoptosis. IL-4 and IFN-gamma regulate B cell CD38 expression and NOS2 expression. We compared IL-4 and IFN-gamma serum levels between CLL patients and normal individuals, and determined whether serum IL-4 and IFN-gamma levels correlated with CLL cell CD38 expression and NOS enzyme activity. IL-4 levels, but not IFN-gamma levels, differed between normal individuals and CLL patients. Furthermore, there was an association of IL-4 levels, but not IFN-gamma levels, with CD38 and NOS2 expression in CLL patients.

Regulation of the expression of CD45 isoforms in the Farage human B cell lymphoma line and its 10.6.1 subline

Different B-cell neoplasias vary in the expression of CD45 isoforms. In the present study two sublines of a human B cell lymphoma- the original Farage line (Farage OL) and the Farage 10.6.1 subline were used to analyze the regulation of the expression of CD45 cell surface determinants. Cells of the Farage OL line constitutively expressed both CD45RO and CD45RA determinants on their cell surface. In contrast, the majority of the cells of the Farage 10.6.1 subline expressed CD45RA, and only few cells were CD45RO+. The low molecular spliced CD45 mRNA, characteristic for CD45RO was found in Farage OL cells, but was almost undetectable in Farage 10.6.1 cells. Following exposure to interleukin-4 (IL-4) a large proportion of the Farage 10.6.1 cells expressed CD45RO while in Farage OL cells the proportion of CD45RO+ was slightly reduced. The low molecular, spliced mRNA characteristic for CD45RO, was increased in Farage 10.6.1 cells following IL4 stimulation, but was slightly reduced in Farage OL cells. The molecular weight of CD45RA molecules produced by Farage cells varied from 185 kDa to 220 kDa while that of CD45RO molecules was 175 kDa. Preliminary attempts were made to determine a possible correlation between the expression of CD45RO and apoptosis in Farage cells. In both the Farage OL and Farage 10.6.1 cells the proportion of Bcl-2+ cells was lower among CD45RO+ cells than among CD45RO- cells. The present study indicates that IL4 has different effects on the alternative splicing of CD45 mRNA in two closely related B cell lymphoma lines. Thus, factors produced by the B lymphoma cells themselves may endow the cells with different patterns of responsiveness to a single stimulatory agent.

Pathways controlling the expression of surface CD21 (CR2) and CD23 (Fc(epsilon)IIR) proteins in human malignant B cells

The aim of the present study was to analyze the pathways regulating the expression of CD21 and CD23 B-cell differentiation antigens on human malignant B cells. Exposure of Farage cells, derived from a human B-cell lymphoma, to phorbol 12-myristate 13-acetate (PMA) down-regulated CD21 and CD23 expression, while interleukin 4 (IL4) inhibited the expression of CD21 but augmented CD23 expression. When Farage cells were stained with either anti-CD21 or anti-CD23 monoclonal antibodies (mAb), subsequent exposure to IL4 failed to change the staining of the cells, indicating that IL4 did not affect the turnover of CD21 and CD23 molecules. Inhibition of protein synthesis with cycloheximide (CXM) had no effect on the expression of CD21 molecules, but abrogated their down-regulation by IL4, suggesting that IL4 induced the synthesis of proteins which modify the processing of CD21 molecules. The inhibitory effect of IL4 on the expression of CD21 and its augmentary effect on the expression of CD23 was abrogated by H7 (1-(5-Isoquinolinylsulfonyl)-2-methylpiperazine), an inhibitor of serine protein kinase. Staurosporine, an additional inhibitor of serine kinases also abrogated the effect of IL4 on CD23 expression. H8 (N-(2-[Methylamino]ethyl)-5-isoquinolinesulfonamide), a preferential inhibitor of protein kinases A and G, and genistein, an inhibitor of tyrosine kinases had no effect on IL4-induced modulation of CD21 and CD23 in Farage cells. The exposure of B-chronic lymphocytic leukemia (CLL) cells to PMA reduced the expression of CD21, but increased the expression of CD23. IL4 had no effect on the expression of CD21 on CLL-cells but strongly enhanced the level of CD23. H7, H8 and genistein each abrogated to a different extent the effect of IL4 on the expression of CD23 by CLL-cells. These data indicate that activation of serine/threonine kinases in malignant B cells inhibited the production of CD21 proteins, while different protein kinases appeared to be involved in up- and down-regulation of CD23 in different B lymphocytes.

Protection from apoptotic cell death by interleukin-4 is increased in previously treated chronic lymphocytic leukemia patients

Chronic lymphocytic leukemia (CLL) cells were cultured in a medium supplemented with 0.01-1 ng/ml interleukin-4 (IL-4) for 18 h, fixed and analyzed on a flow cytometer. The percentage of apoptotic (AP) cells with hypodiploid DNA content was determined from DNA histograms. IL-4 at 0.01 ng/ml protected from spontaneous apoptosis of cells from previously treated CLL patients, but had very little effect on apoptotic death in cultures of cells from untreated patients. The number of AP cells in the absence of IL-4 was similar in cultures from treated and untreated patients. The concentration of IL-4 which inhibited spontaneous apoptosis by 50% was less than 0.01 ng/ml for pretreated patients and close to 1 ng/ml for untreated patients. Stage of the disease had no effect on the level of spontaneous apoptosis and its sensitivity to IL-4. Protection from apoptosis by IL-4 was not accompanied by the upregulation of bcl-2 protein. The number of AP cells in methylprednisolone hemisuccinate (MP) treated cultures from previously treated patients was significantly lower than in cultures from untreated patients in the presence of 0.01-1.0 ng/ml IL-4. Treatment with the combination L-phenylalanine mustard (L-PAM)+ fludarabine induced synergistic apoptotic response. Apoptosis induced by this combination was relatively resistant to IL-4 in patients treated with chlorambucil and prednisone, but not in patients previously treated with fludarabine. Protection from cytotoxicity by IL-4 may be one of the mechanisms of acquired drug resistance in CLL.