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

Production and characterization of a marine monoclonal antibody against human ferritin

Ferritin is an iron storage protein, which plays a hey role in iron metabolism. Measurement of ferritin level in serum is one of the most useful indicators of iron status and also a sensitive measurement of iron deficiency. Monoclonal antibodies may be useful as a tool in various aspects of ferritin investigations. In this paper, the production of a murine monoclonal antibody [mAb] against human ferritin was reported. Balb/c mice were immunized with purified human ferritin and splenocytes of hyper immunized mice were fused with Sp2/0 myeloma cells. After four times of cloning by limiting dilution, a positive hybridoma [clone: 2F9-C9] was selected by ELISA using human ferritin. Anti-ferritin mAb was purified from culture supernatants by affinity chromatography. Determination of the antibody affinity for ferritin by ELISA revealed a relatively high affinity [2.34 10[9] A/[1]] and the isotype was determined to be lgG2a. The anti-ferritin mAb 2F9-C9 reacted with 79.4% of Hela cells in flow cytometry. The antibody detected a band of 20 kDa in K562 cells, murine and human liver lysates, purified ferritin in Western blot and also ferritin in human serum. This mAb can specifically recognize ferritin and may serve as a component of ferritin diagnostic bit if other requirements of the hit are met

Comparison of the photobleaching and photostability traits of alexa fluor 568- and fluorescein isothiocyanate- conjugated antibody

Synthetic fluorescent dyes that are conjugated to antibodies are useful tools to probe molecules. Based on dye chemical structures, their photobleaching and photostability indices are quite diverse. It is generally believed that among different fluorescent dyes, Alexa Fluor family has greater photostability than traditional dyes like fluorescein isothiocyanate [FITC] and Cy5. Alexa Fluor 568 is a member of Alexa Fluor family presumed to have superior photostability and photobleahing profiles than FITC. In this experimental study, we conjugated Alexa Fluor 568 and FITC dyes to a mouse anti-human nestin monoclonal antibody [ANM] to acquire their photobleaching profiles and photostability indices. Then, the fluorophore/antibody ratios were calculated using a spectrophotometer. The photobleaching profiles and photostability indices of conjugated antibodies were subsequently studied by immunocytochemistry [ICC]. Samples were continuously illuminated and digital images acquired under a fluorescent microscope. Data were processed by ImageJ software. Alexa Fluor 568 has a brighter fluorescence and higher photostability than FITC. Alexa Fluor 568 is a capable dye to use in photostaining techniques and it has a longer photostability when compared to FITC

Production of monoclonal antibody against human nestin

We have employed a peptid-based antibody generation protocol for producing antibody against human nestin. Using a 12-mer synthetic peptide from repetitive region of human nestin protein devoid of any N-or O-glycosylation sequences, we generated a mouse monoclonal antibody capable of recognizing human, mouse, bovine, and rat nestin. A wide variety of nestin proteins ranging from 140-250 kDa was detected by this antibody. This antibody is highly specific and functional in applications such as ELISA, flow cytometry, immunocytochemistry, and Western blot assays

Conjucation of R-Phycoerythrin to a polyclonal antibody and F [ab'] 2 fragment of a polyclonal antibody by two different methods

R-phycoerythrin [R-PE], a fluorescent protein from phycobiliprotein family, is isolated from red algae. Conjugation of antibodies to R-PE facilitates multiple fluorescent staining methods. In the present study polyclonal antibodies and polyclonal F[ab']2 fragment antibodies were conjugated to R-PE by two different methods. The efficiency of the methods was evaluated using Immunocytochemistry [ICC] and Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis [SDS-PAGE]. In the first conjugation method, PE was attached to SMCC linker followed by conjugation of antibody to PE-SMCC. In the second method, SH groups were added onto R-PE molecule, while the antibody was attached to SPDP linker. Then, the antibody-SPDP molecule was conjugated to R-PE. Our results showed that the two conjugation methods did not have any abrogative effects on the antibody binding activity

Assessment of thyroglobulin expression in reproductive organs at different stages of mouse estrous cycle

Prevalence of abortion is higher in women with autoimmune thyroid disease. In the majority of cases, however, no abnormality of thyroid function is detected despite the high levels of antithyroid antibodies. The direct influence of such harmful autoantibodies in female reproductive organs may serve a role in pregnancy loss. In this study, expression of thyroglobulin in the reproductive tissues of cycling mice has been evaluated. Stages of estrous cycle were determined by cellular morphology and ratio of epithelial cells to leukocytes in vaginal smear of Balb/C mice. At each phase, the mice were sacrificed and their uterus, ovary and fallopian tubes were removed. Expression of thyroglobulin-specific transcript in endometrium was investigated by two sets of primers using reverse transcriptase-polymerase chain reaction [RT-PCR]. In addition, expression of thyroglobulin in reproductive tissues was assessed by immunohistochemistry and dot blot analysis. The results showed that thyroglobulin mRNA is not expressed in endometrial tissue of Balb/C mice at any stage of estrous cycle. Immunohistochemical analysis also confirmed that thyroglobulin or its cross reactive-antigens are not expressed at the protein level in the female reproductive organs. The results showed that thyroglobulin was not expressed in the reproductive organs of female mice. It is plausible that antithyroglobulin antibodies could interact with newly-generated antigens during placentation and pregnancy

Ectopic expression of sortilin 1 [NTR-3] in patients with ovarian carcinoma

Gene expression profiling of ovarian carcinoma tissues has shown an increase of four-fold expression of SORTl gene. Sortilin 1 [NTR-3] is a 95-100 kDa protein normally expressed in heart, brain, placenta, skeletal muscle, spinal cord, thyroid, and testis. However, its expression has never been reported in normal ovary. Here, we report expression of sortilin 1 in ovarian carcinoma tissues both at gene and protein levels. Sortilin 1 was expressed in all ovarian carcinoma patients [n=15] as well as ovarian carcinoma cell lines [n=5] regardless of their phenotypic characteristics. Non-malignant ovaries [n=6] did not express sortilin 1. The molecular basis for this ectopic expression is not yet clear. Our results showed a major cell surface expression of sortilin 1 rather than ER-Golgi compartment where it is mainly expressed. This finding may introduce sortilin 1 as a novel tumor marker for diagnosis of ovarian carcinoma and may signify its therapeutic value in targeted therapy