Production and characterization of monoclonal antibodies against human prostate specific antigen

Prostate Specific Antigen [PSA] is an important laboratory marker for diagnosis of prostatic cancer. Thus, development of diagnostic tools specific for PSA plays an important role in screening, monitoring and early diagnosis of prostate cancer. In this paper, the production and characterization of a panel of murine monoclonal antibodies [mAbs] against PSA have been presented. Balb/c mice were immunized with PSA, which was purified from seminal plasma. Splenocytes of hyperimmunized mice were extracted and fused with Sp2/0 cells. By adding selective HAT medium, hybridoma cells were established and positive clones were selected by ELISA after four times of cloning. The isotypes of produced mAbs were determined by ELISA and then purified from ascitic fluids using Hi-Trap protein G column. The reactivities of the mAbs were examined with the purified PSA and seminal plasma by ELISA and western blot techniques. Furthermore, the reactivities of the mAbs were assessed in Prostate Cancer [PC alpha], Benign Prostatic Hyperplasia [BPH] and brain cancer tissues by Immunohistochemistry [IHC]. Five anti-PSA mAbs [clones: 2G2-B2, 2F9-F4, 2D6-E8, IgG1/K] and clones [2C8-E9, 2G3-E2, IgG2 alpha/K] were produced and characterized. All mAbs, except 2F9-F4 detected the expression of PSA in PCa and BPH tissues and none of them reacted with PSA in brain cancer tissue in IHC. Besides, all mAbs could detect a protein band around 33 kD alpha in human seminal plasma in western blot. These mAbs can specifically recognize PSA and may serve as a component of PSA diagnostic kit in various biological fluids

High omega-3: omega-6 fatty acids ratio increases fatty acid binding protein 4 and extracellular secretory phospholipase A2IIa in human ectopic endometrial cells

Endometriosis, a common chronic inflammatory disorder, is defined by the atypical growth of endometrium- like tissue outside of the uterus. Secretory phospholipase A2 group Ha [sPLA2-IIa] and fatty acid binding protein4 [FABP4] play several important roles in the inflammatory diseases, Due to reported potential anti-inflammatory effects of omega-3 and omega-6 fatty acids, the purpose of the present study was to investigate the effects of omega-3 and omega-6 polyunsaturated fatty acids [PUFAs] on fatty acid binding protein 4 and extracellular secretory phospholipase A2IIa in cultured endometrial cells. Ectopic and eutopic endometrial tissues obtained from 15 women were snap frozen. After thawing and tissue digestion, primary mixed stromal f and endometrial epithelial cell culture was performed for 8 days in culture mediums supplemented with normal and high ratios of omega-3 and omega-6 PUFA. sPLA2-IIa in the J culture medium and FABP4 level was determined using enzyme immuno assay [EIA] technique. Within ectopic endometrial cells group, the level of cellular FABP4 and extracellular sPLA2-IIa were remarkably increased under high omega-3 PUFA exposure compared with control condition [p=0.014 and p=0.04 respectively]. Omega-3 PUFAs may increase the level of cellular FABP4 and extracellular sPLA2-IIa in ectopic endometrial cells, since sPLAIIa and FABP4 may affect endometriosis via several mechanisms, more relevant studies are encouraged to know the potential effect of increased cellular FABP4 and extracellular sPLA2-IIa on endometriosis

Cloning, expression and characterization of recombinant human Fc receptor like 1, 2 and 4 molecules

The Fc receptor like [FCRL] molecules belong to the immunoglobulin [Ig] superfamily with potentially immunoregulatory function. Among the FCRL family FCRL2 and 4 are predominantly expressed on memory B cells and FCRL1 is a pan- B cell marker. To date, no ligand has been identified for the human FCRL1, 2 and 4 molecules. Cloning, expression, purification and structural analysis of the extracellular domain of human FCRL1, 2 and 4 proteins. In this study, the extracellular part of human FCRL1, 2 and 4 were subcloned into prokaryotic expression vectors pET-28b [+] and transformed into BL21-DE3 E.coli strain. Protein expression was optimized by fine adjustments such as induction time, incubation temperature and expression hosts. Recombinant FCRL proteins were purified by metal affinity chromatography using Ni-NTA resin. Purified FCRL proteins were further characterized by SDS-PAGE and immunoblotting using His-tag and FCRL specific polyclonal antibodies. Our results demonstrated that FCRL1, 2 and 4 were successfully expressed in pET-28b [+] vector. Optimization of the expression procedure showed that IPTG induction at OD600 = 0.9 and overnight incubation at 37[degree]C resulted in the highest expression levels of FCRL proteins ranging from approximately 15% [FCRL1] to 25% [FCRL2 and 4] of the total bacterial lysate proteins. These purified recombinant proteins are potentially a valuable tool for investigating the immunoregulatory function of FCRL molecules and the production of specific mAbs for immunotherapeutic interventions.

Differential WNT gene expression in various subtypes of acute lymphoblastic leukemia

Dysregulation of WNT signaling has been reported in many malignancies. This study was conducted to investigate the expression pattern of 14 members of the WNT gene family in different immunophenotypic subtypes of ALL. Semi-quantitative RT-PCR was performed on samples from 71 ALL patients and 36 age-matched healthy individuals. The ALL patients were categorized into B-ALL [76%], T-ALL [22.6%] and mixed lineage [1.4%] and the B-ALL cases were further classified into pro-B, pre-BI, pre-BII and immature/mature-B based on immunophenotypic results. Among the WNT genes, WNT-7B [p=0.026], WNT-9A [p=0.020] and WNT-16B [p=0.023] were significantly over-expressed, whereas WNT-2B [p=0.033], WNT-5A [p=0.016], WNT-7A [p<0.0001] and WNT-10A [p<0.0001] were down-regulated in B-ALL. Among the T-ALL subtype, however, significant down-regulation of WNT-2B, WNT-5B, WNT-7A, WNT-10A and WNT-11 was evident. Comparison between B-ALL subtypes showed significant over-expression of WNT-7B, WNT-9A and WNT-5B in certain subtypes. Our results suggest contribution of the WNT genes in leukemogenesis of ALL

Comparative expression profile of orphan receptor tyrosine kinase ROR1 in Iranian patients with lymphoid and myeloid leukemias

It has recently been shown that ROR1, a member of the receptor tyrosine kinase family, is overexpressed in leukemic B cells of Chronic Lymphocytic Leukemia [CLL] and a subset of Acute Lymphoblastic Leukemia [ALL]. In this comparative study the expression profile of ROR1 mRNA was investigated in Iranian patients with CLL and Acute Myelogenous Leukemia [AML] and the results were compared with those previously reported in our Iranian ALL patients. RT-PCR was performed on bone marrow and/or peripheral blood samples of 84 CLL and 12 AML patients. CLL samples were classified into immunoglobulin heavy chain variable region [IGHV] gene mutated [n=55] and unmutated [n=29] and also indolent [n=42] and progressive [n=39] subtypes. ROR1 expression was identified in 94% of our CLL patients, but none of the AML patients expressed ROR1. No significant differences were observed between different CLL subtypes for ROR1 expression. Taken together the present data and our previous results on ROR1 expression in ALL, our findings propose ROR1 as a tumor-associated antigen overexpressed in a large proportion of lymphoid [CLL and ALL], but not myeloid [AML] leukemias. Expression of ROR1 seems to be associated to lineage and differentiation stages of leukemic cells with a potential implication for immunotherapy

Optimization of gene transfection in murine myeloma cell lines using different transfection reagents

Purification and isolation of cellular target proteins for monoclonal antibody [MAb] production is a difficult and time-consuming process. Immunization of mice with murine cell lines stably transfected with genes coding for xenogenic target molecules is an alternative method for mouse immunization and MAb production. Here we present data on transfection efficiency of some commercial reagents used for transfection of murine myeloma cell lines. Little is known about transfectability of murine myeloma cell lines by different transfection reagents. Mouse myeloma cell lines [SP[2]/O, NSO, NS1, Ag8, and P3U1] were transfected with pEGFP-N1 vector using Lipofectamine 2000, jetPEI and LyoVec commercial transfection reagents in different combinations. The transfection permissible HEK293-FT cell line was used as a control in transfection procedure. Transfected cells, expressing the Enhanced Green Fluorescent Protein [EGFP], were analyzed by flow cytometry 48 hrs post transfection. Our results showed transfection efficiency of 71%, 57% and 22% for HEK293-FT, 5.5%, 3.4% and 1% for SP[2]/O, 55.7%, 21.1% and 9.3% for NSO, 8.2%, 6% and 5.5% for NS1, 22%, 49.2% and 5.5% for Ag8 and 6.3%, 21.5% and 4.6% for P3U1 cell lines after transfection with Lipofectamine 2000, jetPEI and LyoVec reagents, respectively. Our data indicate that NSO and Ag8 are efficiently transfected by Lipofectamine 2000 and jetPEI reagents. Finally, we propose Ag8 and NSO cell lines as suitable host cells for efficient expression of target genes which can be used for mouse immunization and MAb production

Immunophenotypic subtyping of leukemic cells from Iranian patients with acute lymphoblastic leukaemia: association to disease outcome

Immunophenotypic characterization of the leukemic cells has been widely used as a tool for diagnosis, classification, stratification and prognosis of leukaemia. To investigate the immunophenotypic subtype profiles of Iranian patients with acute lymphoblastic leukemia [ALL] and its association to disease outcome. In this study, a total of 60 Iranian patients with ALL were immunophenotyped by flow cytometry using a panel of monoclonal antibodies specific for CD2, CD3, CD5, CD10, CD13, CD14, CD19, CD20, CD33, CD34, CD45, HLA-DR and TdT molecules. The samples were initially categorized into T-ALL [n=9], B-ALL [n=50] and mixed lineage [n=1] based on the expression patterns of CD3 and CD19 molecules. B-ALL patients could further be classified into four subtypes, including Pro-B [n=7, 11.7%], Pre-B I [n=28, 46.7%], Pre-B II [n=13, 21.7%] and immature/mature B cells [n=2, 3.3%] on the basis of expression of CD10, CD19, CD20, HLA-DR and TdT. Clinical manifestations and laboratory findings of the patients did not reveal association with immunophenotypic sub-types of ALL, with the exception of mediastinal mass and WBC count at the time of diagnosis which were found to be significantly higher in patients with T-ALL compared with B-ALL [p=0.001 and 0.014], respectively. Our results indicate that overall the immunophenotypic profile of Iranian ALL patients is similar to previous reports and it might be used for monitoring of minimal residual disease and prognosis