Discovery of a novel marker for human granulocytes and tissue macrophages: RTL1 revisited.

Here, retrotransposon-like 1 (RTL1) is introduced as a marker for circulating and tissue neutrophils, tissue macrophages, and tumor-associated macrophages (TAM) and neutrophils (TAN). Anti-RTL1 polyclonal and monoclonal antibodies were produced, and their reactivity was examined by Western blotting (WB), ELISA, and immunostaining of human normal and cancer tissues. The reactivity of the anti-RTL1 antibodies with peripheral blood leukocytes and a panel of hematopoietic cell lines was examined. The generated antibodies specifically detected RTL1 in the WB of the placenta and U937 cells. The polyclonal antibody showed excellent reactivity with tissue-resident macrophages, Hofbauer cells, alveolar and splenic macrophages, Kupffer cells, and inflammatory cells in the tonsil, appendix, and gallbladder. In vitro GM-CSF-differentiated macrophages also showed a high level of intracellular RTL1 expression. TAM and TAN also showed excellent reactivity with this antibody. Almost all circulating granulocytes but not lymphocytes or monocytes expressed RTL1 at their surface. Serial sections of the appendix stained with CD15 and RTL1 and placenta stained with CD68 and RTL1 showed a considerable overlap in RTL1 expression in CD15+ granulocytes and CD68+ macrophages. A small percentage of myelomonocytic cell lines was positive for surface RTL1, while promyelocytic, monocytic, megaloblastic, and lymphoblastic cell lines were negative. Endothelial cells of normal and cancer tissues highly expressed RTL1. RTL1 could be considered a new marker for different normal tissue macrophages, TAM, circulating and tissue neutrophils, and TAN.

Expression profiling of RTL1 in human breast cancer tissues and cell lines.

Breast cancer (BC) is the most common cancer in females. In this regard, the identification of molecular alterations driving BC is an immediate need for developing effective immunotherapeutic tools. Here we investigated the expression of a placenta-specific protein, Retrotransposon-like 1 (RTL1) in a series of BC tissues and cell lines. RTL1-specific polyclonal antibody was generated and characterized. Using tissue microarray immunohistochemistry, expression of RTL1 in a total of 147 BC and 36 non-malignant breast tissues was investigated and the association of patient's clinicopathological parameters with RTL1 expression was then examined. Expression of RTL1 in four BC cells was assessed by flow cytometry, immunofluorescent staining and Western blotting. We observed a mixture pattern of nuclear and cytoplasmic RTL1 expression in most tissues examined, however nuclear expression was found to be dominant pattern of expression. The level of nuclear RTL1 expression was significantly higher in BC tissues (P < 0.001). A statistically significant association between nuclear RTL1 expression and histological grade and vascular invasion was found (P < 0.001 and P < 0.05). All cell lines expressed RTL1 with varying degrees at their surface. The most invasive BC cell line MDA-MB-231, compared to T-47D, SKBR3 and MCF7 expressed higher levels of RTL1 at their surface. Cells with a low level of surface expression, expressed high levels of intracellular RTL1 expression. Our antibody reacted with a specific band of about 125 KD in normal human placenta and all cell lines examined. In contrast to placenta, two additional bands were also observed in cancer cell lines. Our results showed for the first time that RTL1 is differentially expressed in BC compared to non-malignant breast tissues and is associated with a higher grade and vascular invasion. In BC cells with high metastatic and invasive potential, this antigen is mostly confined to cell surface compartment indicating the possibility of using antibody-based immunotherapy for advanced metastatic BC patients.

Thyroid peroxidase in human endometrium and placenta: a potential target for anti-TPO antibodies.

Autoimmune thyroid disease is the most common endocrine disorder during pregnancy. Thyroid autoantibodies (TAs) have been suggested to serve a role in implantation failure and spontaneous abortion. Until now, there are no data on the potential interaction of TAs with human reproductive organs. Here, we set out for the first time to test this hypothesis by studying the expression of thyroid peroxidase (TPO) at gene and protein level in human reproductive organs. Endometrial samples were taken from normal women, and placenta tissues were collected after full-term caesarian section. Expression of TPO messenger RNA (mRNA) was investigated by qRT-PCR. In addition, polyclonal anti-TPO antibodies were produced and the expression of TPO protein in mentioned tissues was evaluated by immunohistochemistry and Western blot analysis. The reactivity of anti-TPO antibody in human embryos was evaluated by immunofluorescent staining. For the first time, our study showed that TPO is expressed at gene and protein levels in endometrium and placenta. TPO expression was mainly localized to glandular and luminal epithelial cells in the endometrium. In placenta, the syncytiotrophoblasts and invasive trophoblast cells were the main cell types that expressed TPO protein. Specific band of approximately 110 kDa was observed in all endometrial and placental tissues by Western blot analysis. However, no expression of TPO protein was observed in human embryo. TPO expression in endometrium and placenta may explain higher frequency of abortion and infertility in patients with thyroid autoimmunity.

Discovery of a potential biomarker for immunotherapy of melanoma: PLAC1 as an emerging target.

BACKGROUND: Melanoma has increased in incidence worldwide prompting investigators to search for new biomarkers for targeted immunotherapy of this disease. Placenta specific 1 (PLAC1) is a new member of cancer-testis antigens with widespread expression in many types of cancer. Here, we aimed to study for the first time the expression pattern of PLAC1 in skin cancer samples including cutaneous melanoma, basal cell carcinoma (BCC), squamous cell carcinoma (SCC) in comparison to normal skin and nevus tissues and potential therapeutic effect of anti-PLAC1 antibody in melanoma cancer cell lines in vitro. MATERIALS AND METHODS: Polyclonal and monoclonal antibodies were applied for immunohistochemical profiling of PLAC1 expression using tissue microarray. The cytotoxic action of anti-PLAC1 antibody alone or as an antibody drug conjugate (with anti-neoplastic agent SN38) was investigated in melanoma cell lines. RESULTS: We observed that 100% (39 of 39) of melanoma tissues highly expressed PLAC1 with both cytoplasmic and surface expression pattern. Investigation of PLAC1 expression in BCC (n = 110) samples showed negative results. Cancer cells in SCC samples (n = 66) showed very weak staining. Normal skin tissues and nevus samples including congenital melanocytic nevus failed to express PLAC1. Anti-PLAC1-SN38 exerted a specific pattern of cytotoxicity in a dose- and time-dependent manner in melanoma cells expressing surface PLAC1. CONCLUSIONS: Our findings re-inforce the concept of re-expression of embryonic/placental tissue antigens in cancer and highlight the possibility of melanoma targeted therapy by employing anti-PLAC1 antibodies. The data presented here should lead to the future research on targeted immunotherapy of patients with melanoma.

Human immune response to Phlebotomus sergenti salivary gland antigens in a leishmaniasis-endemic focus in Iran.

Salivary proteins specific antibodies have been shown to be useful biomarkers of exposure to sand fly bites. This study aimed to investigate the level, duration, and dynamics of the human immune response against the SGL of Phlebotomus sergenti Parrot, 1917 (Diptera: Psychodidae), and to assess the immunoreactivity of human sera with SGL components in an endemic area of anthroponotic cutaneous leishmaniasis (ACL) in Iran. The study was carried out in 2-phase; longitudinal and cross-sectional. Sand flies were collected monthly from indoors and outdoors. In the longitudinal study, sera from healthy volunteers were collected monthly, and in the cross-sectional study, sera from healthy volunteers and patients with ACL lesion/s, were collected for immunoassay studies. The level of anti-P. sergenti saliva IgG was detected using the ELISA. Immunoreactivity of individual human sera with saliva components was also assessed by western blotting. Phlebotomus sergenti was the predominant sand fly species in the study area. The maximum and minimum percentages of IgG responses were seen in October (66%) and March (29%), respectively. Additionally, the cross-sectional study showed that 59.3% of the healthy volunteers and 80% of the patients were IgG positive. The antibody response against P. sergenti salivary gland was high during the sand fly active season and declined by the end of the activity of the vectors.  Antibody response against the SGL components of P. sergenti was transient and individual-specific. Some individuals shared a strong reaction against certain individual antigens, which could be considered as vector exposure markers for further investigation. LIST OF ABBREVIATIONS: ELISA: Enzyme-Linked Immunosorbent Assay; SDS PAGE: Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis; SGL: Salivary Gland Lysate; ACL: Anthroponotic Cutaneous Leishmaniasis; PBS: Phosphate Buffered Saline; BCA: Bicinchoninic Acid; PBS-T: Phosphate Buffered Saline Tween; FBS: Fetal Bovine Serum; HRP: Horseradish Peroxidase; TMB: 3,3',5,5'-Tetramethylbenzidine; PVDF: Polyvinylidene Difluoride; SGA: Salivary Gland Antigens; OD: Optical Density; KDa: Kilodalton; VL: Visceral Leishmaniasis; CL: Cutaneous Leishmaniasis; SGs: Salivary glands.

Evaluating the Immunoreactivity of Ailanthus Altissima (The Tree of Heaven) Pollen Extract in Atopic Patients.

IgE-mediated hypersensitivity reaction to pollens is a common health problem in atopic patients. In this regard, the assessment of the allergenicity of highly pollinating plants would be demanding. Based on the increment of Ailanthus altissima (A. altissima) tree in some parts of Iran and considering its probable role in respiratory allergy, in this study, we aimed to investigate its IgE-immunoreactivity and in diagnostic applications. One hundred and twenty-five allergic rhinitis patients who were diagnosed as high IgE responders and demonstrated seasonal rhinitis or rhinoconjunctivitis, as well as 20 healthy controls (HCs) with no allergic symptoms, were enrolled in this study. Total protein extract was prepared from A. altissima pollens and subjected to quality control experiments and finally used in ELISA and western blotting studies. Approximately 24% of the atopic patients (30 from 125) showed positive immunoreactivity to A. altissima extract. The median (IQR) of absorbance (450 nm) of the specific IgE against A. altissima pollen extract in HCs and positive groups were 0.33 (0.28-0.42) and 0.59 (0.36-0.79), respectively (p<0.001). Receiver operating characteristics (ROC) curve analysis of the specific ELISA results, revealed a cut-off value of 0.46 and a sensitivity of 70% and specificity of 100%. Western blotting with the sera positive cases revealed that the main immunoreactive proteins range from 10 to 70 kDa. This study revealed that some of A. altissima pollen proteins ranging from 10 to 70 kDa show IgE-reactivity in atopic patients and may play a role in their allergic reaction symptoms.

Evaluation of the frequency of CD5+ B cells as natural immunoglobulin M producers and circulating soluble CD5 in patients with bladder cancer.

Bladder cancer is the most common malignancy of the genitourinary tract. It is the fourth most common malignancy in men and the fifth most common malignancy in the general population, with a high recurrence rate. CD5+ B lymphocytes are a subset of B lymphocytes, which contribute to innate immune responses. These cells are involved in the spontaneous production of self-reactive natural antibodies. On the other hand, natural antibodies can recognize tumor-associated antigens, including proteins or carbohydrates, and eliminate these cells in a complement-dependent manner or via induction of apoptosis. Besides surface CD5, the soluble form of this molecule is involved in the regulation of immune system. Considering the role of CD5+ B cells in the production of natural immunoglobulin M (IgM) and role of these antibodies in antitumor responses, in this study, we aimed to investigate the frequency of CD5 in B cells and to evaluate the diagnostic potential of these cells and also soluble CD5 (sCD5) in patients with bladder cancer. Blood specimens were collected from 40 patients with bladder cancer, who were referred to Sina Hospital in Tehran, IRAN. The levels of CD5+ and CD5- B lymphocytes were measured in the peripheral blood via flow cytometry, and the levels of sCD5 and total IgM were investigated in the serum by ELISA and nephlometry techniques, respectively. The frequency of CD5+ and CD5- B cells was significantly lower in patients, compared with the healthy controls. Detectable levels of sCD5 were found in two patients (5%), while total IgM showed no significant difference between the patient and control groups. The present results suggest that B cell subsets may be affected by malignancy. Therefore, further research is needed to identify B cells and their soluble markers for diagnosis of patients with bladder cancer.

Seasonal and Physiological Variations of Phlebotomus papatasi Salivary Gland Antigens in Central Iran.

BACKGROUND: Sand fly saliva helps parasite establishment and induce immune responses in vertebrate hosts. In the current study, we investigated the modulation of Phlebotomus papatasi salivary gland antigen expression by seasonal and biological factors. METHODS: Sand flies were grouped according to physiological stages such as unfed, fed, semi-gravid, gravid, parous, nulliparous, infected or non-infected with Leishmania major and based on the season in which they were collected. Salivary gland antigens (SGAs) were analyzed using SDS-PAGE and the antibody response against SGAs in Rhombomys opimus was determined by ELISA and Western blot. RESULTS: The highest protein content was found in the salivary glands of unfed sand flies. The saliva content was higher in parous compared to nulliparous, in summer compared to spring, and in Leishmania-infected compared to non-infected flies. The salivary gland lysate (SGL) electrophoretic pattern variations were observed among sand flies with various physiological stages particularly from 4-9 protein bands of 14-70 kDa. The SGL of unfed and gravid flies had extra protein bands compared to fed and semi-gravid sand flies. There was missing protein bands in SGL of parous compared to nulliparous; and in summer compared to spring collected flies. Rhombomys opimus serum reacted strongly with an antigenic band of around 28 kDa in the SGL of all sand fly groups. CONCLUSION: Certain biological and environmental characteristics of wild populations of vector sand flies affect the protein content and antigenicity of saliva. This might have an important implication in the design of vector-based vaccines.

Placental Kisspeptins Differentially Modulate Vital Parameters of Estrogen Receptor-Positive and -Negative Breast Cancer Cells.

Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2-30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production.

Production and Characterization of Monoclonal Antibodies against Human Prostate Specific Antigen.

BACKGROUND: 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. METHODS: 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 (PCa), Benign Prostatic Hyperplasia (BPH) and brain cancer tissues by Immunohistochemistry (IHC). RESULTS: Five anti-PSA mAbs (clones: 2G2-B2, 2F9-F4, 2D6-E8, IgG1/К) and clones (2C8-E9, 2G3-E2, IgG2a/К) 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 kDa in human seminal plasma in western blot. CONCLUSION: These mAbs can specifically recognize PSA and may serve as a component of PSA diagnostic kit in various biological fluids.

Albuminated PLGA nanoparticles containing bevacizumab intended for ocular neovascularization treatment.

Bevacizumab, an anti-VEGF antibody, has demonstrated trustworthy effects in treatment of retinal and choroidal neovascularization that both are crucial sight threatening conditions. However, the weak point is the short half-life of the drug in vitreous which necessitates frequent intravitreal injections. Accordingly employing controlled-release drug delivery systems such as polymeric nanoparticles (NPs) has been suggested. In this study albuminated-PLGA-NPs containing bevacizumab were prepared and studied intended for reducing the number of injections. NPs were formulated by double-emulsion method and a single dose of NPs was intravitreally injected to rabbits. The drug concentrations in vitreous and aqueous humor were assayed in different time intervals using ELISA and intraocular pharmacokinetic parameters were calculated. Moreover, coumarin-6 loaded albuminated-PLGA-NPs were employed to evaluate the distribution and persistence of the NPs in the posterior segment. Results revealed that the bevacizumab vitreous concentration maintained above 500 ng mL(-1) for about 8 weeks and 3.3 times elevation was observed in the drug vitreous MRT compared with the control. According to coumarin-6 NP tests, fluorescence emissions in posterior tissues were observed for 56 days which confirmed the nanoparticles persistence in ocular tissues during the test span. Therefore our prepared formulation may offer improvements in treatment of eye posterior segment neovascularization.

High placenta-specific 1/low prostate-specific antigen expression pattern in high-grade prostate adenocarcinoma.

BACKGROUND: The scarcity of effective therapeutic approaches for prostate cancer (PCa) has encouraged steadily growing interest for the identification of novel antigenic targets. Placenta-specific 1 (PLAC1) is a novel cancer-testis antigen with reported ectopic expression in a variety of tumors and cancer cell lines. The purpose of the present study was to investigate for the first time the differential expression of PLAC1 in PCa tissues. METHODS: We investigated the differential expression of PLAC1 in PCa, high-grade prostatic intraepithelial neoplasia (HPIN), benign prostatic hyperplasia (BPH), and nonneoplastic/nonhyperplastic prostate tissues using microarray-based immunohistochemistry (n = 227). The correlation of PLAC1 expression with certain clinicopathological parameters and expression of prostate-specific antigen (PSA), as a prostate epithelial cell differentiation marker, were investigated. RESULTS: Placenta-specific 1 (PLAC1) expression was increased in a stepwise manner from BPH to PCa, which expressed highest levels of this molecule, while in a majority of normal tissues, PLAC1 expression was not detected. Moreover, PLAC1 expression was positively associated with Gleason score (p ≤ 0.001). Interestingly, there was a negative correlation between PLAC1 and PSA expression in patients with PCa and HPIN (p ≤ 0.01). Increment of PLAC1 expression increased the odds of PCa and HPIN diagnosis (OR 49.45, 95 % CI for OR 16.17-151.25). CONCLUSION: Our findings on differential expression of PLAC1 in PCa plus its positive association with Gleason score and negative correlation with PSA expression highlight the potential usefulness of PLAC1 for targeted PC therapy especially for patients with advanced disease.

Immunohistochemical characterization of novel murine monoclonal antibodies against human placenta-specific 1.

Human PLAC1 (placenta-specific 1) is a new member of cancer-testis antigens with 212 amino acids, and its expression is restricted to placenta and at much lower levels to testis. Recently, ectopic expression of the PLAC1 transcript has been demonstrated in a wide range of human tumors and cancer cell lines with a proposed function in tumor cell growth. No monoclonal anti-PLAC1 antibody applicable to immunohis-tochemical staining is available so far. To better understand the PLAC1 expression and localization, we aimed to produce monoclonal antibodies (mAbs) against the extracellular region of PLAC1. Mice were immunized with a synthetic peptide corresponding to the C-terminal 11 amino acids of PLAC1 conjugated with a carrier protein. Hybridomas were produced by standard protocol and screened for positive reactivity by enzyme-linked immunosorbent assay. Reactivity of final two clones was then assessed by Western blotting (WB), immunohistochemistry (IHC), and immunocytochemistry (ICC). Both clones showed a specific immunostaining pattern in human term placenta as the positive control. Reactivity was mostly localized to the cytoplasm of syncytiotrophoblasts. One of the clones showed an excellent staining signal in breast, ovary, and prostate cancer cell lines. Importantly, no reactivity was observed with human lymph node cells or prostate. None of the mAbs were able to detect PLAC1 in Western blot. Based on the present results, these mAbs can be used for detection of PLAC1 in IHC and ICC techniques.

Production and characterization of a murine monoclonal antibody against human ferritin.

BACKGROUND: Ferritin is an iron storage protein, which plays a key 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. METHODS: 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. RESULTS: Determination of the antibody affinity for ferritin by ELISA revealed a relatively high affinity (2.34×10(9) M (-1)) and the isotype was determined to be IgG2a. 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. CONCLUSION: This mAb can specifically recognize ferritin and may serve as a component of ferritin diagnostic kit if other requirements of the kit are met.

The protective effect of albumin on bevacizumab activity and stability in PLGA nanoparticles intended for retinal and choroidal neovascularization treatments.

The rapidly growing applications of antibody-based therapeutics requires novel approaches to develop efficient drug delivery systems in which biodegradable polymeric nanoparticles are amongst the best candidates. In the present study bevacizumab loaded PLGA nanoparticles were formulated by water-in-oil-in-water emulsion method. Protein inactivation and aggregation are the major drawbacks of this technique. Therefore protective ability of various stabilizers was studied during entrapment process. Probable changes in VEGF165 binding capability of bevacizumab was assayed by ELISA which portrays the antibody's bio-efficiency. Probable breakage of bevacizumab and its secondary and tertiary structural integrity upon entrapment were analyzed by SDS-PAGE and circular dichroism spectroscopy, respectively. In vitro and ex vivo released bevacizumab from the prepared nanoparticles was also investigated. Results revealed that the protein interfacial adsorption is the foremost destabilizing factor in the double emulsion method and incorporation of appropriate concentrations of albumin could protect bevacizumab against entrapment stress. Ex vivo release results, in rabbit vitreous, indicated the ability of prepared nanoparticles in prolonged release of the active antibody. Consequently this approach was an attempt to achieve sustained release PLGA nanoparticle formulation with the aim of protecting integrity and performance of entrapped bevacizumab.

Distribution of vitamin D receptor and 1α-hydroxylase in male mouse reproductive tract.

Vitamin D has been introduced as one of the main regulators of spermatogenesis. Here, for the first time, we evaluated the expression of vitamin D receptor (VDR) and 1α-hydroxylase in all organs of male mice reproductive tract by immunohistochemistry and Western blotting. Epithelial cells of epididymis, seminal vesicle, coagulating gland, ductus deferens, preputial gland, and prostate were the prominent cell types that concomitantly expressed VDR and 1α-hydroxylase. Nearly all cell types in testis expressed both proteins. Interestingly, VDR intensity in epididymis epithelial cells was reduced toward cauda, in which only strong staining of stereocilia was observed. Although been positive in caput epididymis, sperms lost their VDR expression in cauda region. In all organs, sperms failed to express 1α-hydroxylase. Specific bands of the VDR and 1α-hydroxylase were determined in all tissues, except testis in which novel unprecedented isoforms of 1α-hydroxylase were observed. Our findings could provide further convincing evidence of pivotal role of this hormone in male reproductive biology.

Accurate sensitivity of quantum dots for detection of HER2 expression in breast cancer cells and tissues.

Here we introduce novel optical properties and accurate sensitivity of Quantum dot (QD)-based detection system for tracking the breast cancer marker, HER2. QD525 was used to detect HER2 using home-made HER2-specific monoclonal antibodies in fixed and living HER2(+) SKBR-3 cell line and breast cancer tissues. Additionally, we compared fluorescence intensity (FI), photostability and staining index (SI) of QD525 signals at different exposure times and two excitation wavelengths with those of the conventional organic dye, FITC. Labeling signals of QD525 in both fixed and living breast cancer cells and tissue preparations were found to be significantly higher than those of FITC at 460-495 nm excitation wavelengths. Interestingly, when excited at 330-385 nm, the superiority of QD525 was more highlighted with at least 4-5 fold higher FI and SI compared to FITC. Moreover, QDs exhibited exceptional photostability during continuous illumination of cancerous cells and tissues, while FITC signal faded very quickly. QDs can be used as sensitive reporters for in situ detection of tumor markers which in turn could be viewed as a novel approach for early detection of cancers. To take comprehensive advantage of QDs, it is necessary that their optimal excitation wavelength is employed.

A monoclonal antibody against leptin.

Leptin is an important protein that regulates energy storage and homeostasis in humans and animals. Leptin deficiency results in various abnormalities such as diabetes, obesity, and infertility. Producing a high affinity monoclonal antibody against human leptin provides an important tool to monitor and trace leptin function in different biological fluids. In this study, recombinant human leptin was conjugated to KLH and injected into mice. After immunization, mouse myeloma SP2/0 cells were fused with murine splenocytes followed by selection of antibody-producing hybridoma cells. After screening of different hybridoma colonies by ELISA, a high affinity antibody was selected and purified by affinity chromatography. The affinity constant of the antibody was measured by ELISA. Western blot, immunocytochemistry, and flow cytometry experiments were used to characterize the antibody. The anti-leptin antibody had a high affinity (around 1.13 × 10(-9) M) for its antigen. The saturation of the antibody with leptin (20 moles leptin per 1 mole antibody) in Western blot analysis proved that the antibody had specific binding to its antigen. Immunocytochemistry and flow cytometry on JEG-3 (human placental choriocarcinoma cell) cells revealed that the anti-leptin antibody recognized intracellular leptin. In conclusion, we report here the production and characterization of a murine anti-leptin antibody with high affinity for human leptin.

Comparison of the Photobleaching and Photostability Traits of Alexa Fluor 568- and Fluorescein Isothiocyanate- conjugated Antibody.

OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULTS: Alexa Fluor 568 has a brighter fluorescence and higher photostability than FITC. CONCLUSION: Alexa Fluor 568 is a capable dye to use in photostaining techniques and it has a longer photostability when compared to FITC.

Investigating Association of Three Polymorphisms of Coagulation Factor XIII and Recurrent Pregnancy Loss.

PROBLEM: among important suspected causes of thrombophilia in women with recurrent pregnancy loss (RPL) are the polymorphisms of coagulation factor XIII (FXIII) gene. We performed a case-control study on the association between three polymorphisms of factor XIII (FXIII G103T, FXIII A614T and FXIII C1694T) and RPL in Iranian women. METHOD OF STUDY: DNA samples from peripheral blood of 100 female patients with at least two recurrent abortions, as case group, and 100 healthy women with history of at least two successful deliveries were subjected to PCR-RFLP, and the frequencies of the polymorphisms were calculated and compared between the two groups. RESULTS: the prevalence of FXIII G103T polymorphism was 29% in the case group and 17% in the control group (P = 0.158). The frequencies of FXIII A614T and FXIII C1694T were 84% and 66% in the case group and 48% and 31% in the control group (P <0.001 and P < 0.001), respectively. The two latter polymorphisms are associated with RPL in Iranian women and increase the risk of RPL. A correlation was also found between FXIII A614T and FXIII C1694T polymorphisms (P < 0.001). CONCLUSION: we suggest the evaluation of FXIII A614T and FXIII C1694T polymorphisms in women with RPL.