Enhancement of monoclonal antibody production after single and combination treatment of the hybridoma cells with all-trans retinoic acid and docosahexaenoic acid: An in vitro and in vivo study.

Murine hybridoma cells can produce monoclonal antibody (MAb) and the production of these antibodies in culture and peritoneum can be affected by different factors, including stimulants, inhibitors and supplements. Among these factors, the impact of micronutrients on the production of MAbs by mouse hybridoma cells has not fully been explored. In this study the murine hybridoma cells, M3C5, were cultured and treated with different concentrations of ATRA and DHA, alone, in combinations, and at different time of exposure. Then, changes in the production of MAb in culture medium were evaluated using ELISA. The hybridoma cells after single and combined treatment with ATRA, DHA and vehicles were IP injected to Balb/c mice and the changes in production of MAb in ascites were determined by ELISA. The results showed that single and combined treatment of ATRA and DHA elevated the production of MAb by hybridoma cells in both in vivo and in vitro. The production of MAb following in vitro single treatment with 1 µM of ATRA and 10 µM of DHA for 2 days was significantly increased. The in vitro effects of ATRA on increase of MAb production was obtained more than DHA. The MAb productions in combined treatment with 0.5 µΜ of ATRA plus 5 µΜ of DHA were significantly increased in in vivo and in vitro. However, the effect of DHA was obtained more significant in in vivo conditions. The results of this study showed for the first time that in vitro and in vivo treatments of ATRA and DHA could increase the production of MAb in mouse M3C5 hybridoma cells.

Vitamin A Decreases Cytotoxicity of Oxidized Low-Density Lipoprotein in Patients with Atherosclerosis.

BACKGROUND: Oxidized low-density lipoprotein (ox-LDL) is implicated in initiation and progression of atherosclerosis. Previously, we found that ox-LDL increases vulnerability of peripheral blood mononuclear cells (PBMCs) in atherosclerotic patients compared to controls. Vitamin A induces proliferation of PBMCs. The aim of this study was to determine the effect of vitamin A supplementation on PBMC survival against LDL and different doses of ox-LDL. METHOD: In this double-blind placebo-controlled trial, we recruited 35 atherosclerotic patients and 38 healthy controls and randomly allocated them into placebo and vitamin A groups, which received either placebo or 25,000 IU/day of vitamin A for 3 months. PBMCs were isolated, cultured, and stimulated by 1 µg/mL LDL as well as 1 µg/mL and 50 µg/mL ox-LDL. The stimulation indexes (SIs) of PBMCs were calculated to identify cell viability. Additionally, the circulating ox-LDL levels were measured by ELISA. RESULTS: Viability of PBMCs stimulated by 50 µg/mL ox-LDL significantly increased following vitamin A supplementation in patients (p < 0.01). The levels of circulating ox-LDL were not changed by vitamin A treatment. Ox-LDL levels were strongly and positively correlated to SI of PBMCs stimulated by 1 µg/mL LDL and1 µg/mL ox-LDL in all groups. CONCLUSION: Vitamin A decreases cytotoxicity of high-dose ox-LDL and improves PBMC viability. The protective effect of vitamin A is not mediated by an antioxidative mechanism, but may instead have been due to intracellular protection of the apoptotic machinery or induction of proliferation of the cells. Higher levels of ox-LDL increase PBMC irritability in all participants.

The effect of vitamin A supplementation on stimulated T-cell proliferation with myelin oligodendrocyte glycoprotein in patients with multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune disease whereby myelin sheath of the central nervous system is destroyed. Vitamin A is known to play a role in the immune system. It has been recognized that some metabolites of vitamin A can be used effectively to treat experimental autoimmune encephalomyelitis (EAE). AIMS: The effect of vitamin A as retinyl palmitate on T-cell proliferation in MS patients. SETTING AND DESIGN: This study is a double blind clinical trial of two test groups over a period of 6 months. MATERIALS AND METHODS: Thirty five multiple sclerosis (MS) patients were divided into two groups. One group received 25,000 IU/day vitamin A (as retinyl palmitate) and the other group were administered a placebo. The peripheral blood mononuclear cells (PBMCs) were separated and stimulated with myelin oligodendrocyte glycoprotein (MOG) and phytohemagglutinin (PHA) before and after the trial period. BrdU calorimetric assay was performed to measure cell proliferation. STATISTICAL ANALYSIS: Analysis of covariance (ANCOVA) and paired t-test were used to analyze the data. RESULTS: Observations showed statistical significant differences in the reduction of cell proliferation in the presence of MOG and fetal calf serum (FCS) in the culture medium, between patients receiving vitamin A and the placebo (P = 0.046). Although, this difference was not significant between the two vitamin A and placebo groups in MOG treatment with human serum, a decrease was observed in the group of patients taking vitamin A supplements (P = 0.019). Phytohemagglutinin did not cause any change in cell proliferation between the two groups. CONCLUSION: The results suggest supplementation with retinyl palmitate in patients with MS reduce MOG stimulatory effects on T-cells.

The influence of feeding linoleic, gamma-linolenic and docosahexaenoic acid rich oils on rat brain tumor fatty acids composition and fatty acid binding protein 7 mRNA expression.

BACKGROUND: Experimental studies indicate that gamma linolenic acid (GLA) and docosahexaenoic acid (DHA) may inhibit glioma cells growth but effects of oral consumption of these fatty acids on brain tumor fatty acid composition have not been determined in vivo. METHODS: GLA oil (GLAO; 72% GLA), DHA oil (DHAO; 73% DHA) were fed to adult wistar rats (1 mL/rat/day) starting one week prior to C6 glioma cells implantation and continued for two weeks after implantation. Control group were fed same amount of high linoleic acid safflower oil (74-77% linoleic acid). Fatty acid composition of tumor samples was determined in a set of 8-12 animals in each group and serum fatty acid in 6 animals per each group. Gene expression of tumor fatty acid binding protein 7 (FABP7), epidermal growth factor receptor (EGFR), peroxisome proliferator activated receptor gamma (PPAR-gamma) and retinoid x receptor-alpha (RXR-alpha) were determined in a set of 18 animals per group. RESULTS: DHAO feeding increased EPA of brain tumors and decreased ratio of n-6/n-3 fatty acids. Serum levels of EPA were also increased in DHAO group. A similar trend in serum and tumor levels of DHA were observed in DHAO group but it did not achieve statistical significance. GLAO increased serum concentration of GLA but had no significant effect on tumor GLA or dihomo-gamma linolenic acid (DGLA) concentrations. Gene expression of FABP7 was up-regulated in tumors of DHAO group but no other significant effects were observed on EGFR, PPAR-gamma or RXR-alpha expression, and expression of these genes in tumors of GLAO were not different from SFO group. CONCLUSION: Dietary supplementation of DHA containing oil could be an effective way to increase levels of long chain n-3 fatty acids in brain tumors and this increase may be mediated partly by up-regulation of FABP7 expression.