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Background: Evidence on seroconversion profile of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients is limited. We mainly aimed to evaluate seroconversion and persistence of virus-specific antibodies in patients infected by coronavirus disease 2019 (COVID-19)., Methods: This prospective study was conducted on 118 patients with COVID-19 presentations admitted to three hospitals in Iran and recovered from the disease, during April and May 2020. Presence of COVID-19 was confirmed by Polymerase Chain Reaction (PCR) testing on nasopharyngeal swabs. Serum samples were collected at different time points, including 0-5, 6-15, 16-25, 26-35, and 36-95 days of clinical symptom onset. For measurement of SARS-CoV-2-specific IgG and IgM antibody titers, Iran's Food and Drug Administration-approved SARS-CoV-2 ELISA kits were used., Results: Serologic assay revealed that 37.3% of patients (n=44) were positive for IgM at 0-5 days interval after clinical symptom onset. This rate was 60.2% (n=71) for IgG. There were increasing IgM and IgG seroconversion rates during first 25 days of clinical symptom onset, but seropositivity started to decrease thereafter, which was more evident for IgM (17.9%) than IgG (58.9%) at the 36-95 days post symptoms appearance. In other words, it was found that 83.6% of IgM-positive and 32.9% of IgG-positive patients in the first month of clinical symptom onset became seronegative in the third month of clinical symptom onset., Conclusion: The findings demonstrated that antibody responses to SARS-CoV-2 infection were developed in recovered COVID-19 patients; however, some of them were seronegative three months after onset of relevant symptoms. Furthermore, the stability of anti-SARS-CoV-2 antibodies could also correct our expectations from COVID-19 vaccination responses., Competing Interests: Conflict of Interest All authors declare no conflict of interest., (Copyright© 2022 Avicenna Research Institute.)

The emergence of SARS-CoV-2, responsible for coronavirus disease-2019 (COVID-19), has become a major global health problem. The molecular testing is the accepted assay in SARS-CoV-2 detection. However, there are several reasons for low sensitivity by RNA detection, causing challenges in SARS-CoV-2 diagnosis. In this study, we aimed to investigate serological patterns of SARS-CoV-2 specific IgM, and IgG in 111 hospitalized, and 34 recovered COVID-19 patients and 311 prepandemic normal serum specimens by ELISA. The validity of the ELISA kits was evaluated using samples from normal and recovered cases. This showed that 98.1%, and 98.4% of prepandemic normal samples were negative for anti-SARS-CoV-2 IgM, and IgG, respectively. Assessment of 34 COVID-19 confirmed recovered patients showed a test sensitivity of 76.5%, and 94.1% for IgM, and IgG, respectively. In COVID-19 hospitalized patients, 42.3%, and 51.4% were positive for IgM and IgG, respectively. Viral RNA was not detectable in 43.3% of the hospitalized patients. Interestingly, combined molecular and serological testing improved the sensitivity of COVID-19 diagnosis to 79.6%. Using PCR with combined IgM/IgG results augmented the patient diagnosis sensitivity to 65.3% and 87.2% in ≤ 7 days, and > 7 days intervals, respectively. Overall, serological tests in combination with PCR can improve the sensitivity of COVID-19 diagnosis., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly transmits in general population, mainly between health-care workers (HCWs) who are in close contact with patients., Objective: To study the seropositivity of HCWs as a high-risk group compared to general population., Methods: 72 samples were obtained from HCWs working in Masih Daneshvari hospital as one of the main COVID-19 admission centers in Tehran, during April 4 to 6, 2020. Also we collected 2021 blood samples from general population. The SARS-CoV-2 specific IgM, and IgG antibodies in the collected serum specimens were measured by commercial ELISA kits., Results: Based on the clinical manifestations, 25.0%, 47.2%, and 27.8% of HCWs were categorized as symptomatic with typical symptoms, symptomatic with atypical symptoms, and asymptomatic, respectively. Symptomatic individuals with typical and atypical symptoms were 63.2% and 36.8% positive in RT-PCR test, respectively. Anti-SARS-CoV-2 IgM and IgG antibodies were detected in 15.3% and 27.8% of HCWs samples, respectively. Antibody testing in the general population indicated that SARS-CoV-2 specific IgM and IgG were found in (162/2021) 8%, and (290/2021) 14.4%, respectively. The frequency of positive cases of IgM and IgG were significantly increased in HCWs compared to general population (p= 0.028 for IgM and p= 0.002 for IgG)., Conclusion: The frequency of SARS-CoV-2 specific antibodies in HCWs was higher than general population indicating a higher viral transmission via close exposure with COVID-19 patients.

Background: Multiple sclerosis is a chronic incapacitating disease of the central nervous system, it has been reported that the disturbance in the development and function of Treg subpopulations is associated with the disability status in the RRMS. Accordingly, in the current study, the objective was to specify nanocurcumin effects on Treg cells frequency, and function in patients with RRMS., Methods and Materials: 50 patients with RRMS were enrolled in this study in which 25 were treated for at least six months with nanocurcumin capsules while the other half received placebo capsules as the control group. The blood sample was collected prior to the administration of nanocurcumin and placebo capsules and following six months. At baseline and after a six-month treatment, the frequency of Treg lymphocytes, the expression of transcription factor related to these cells and the secretion levels of cytokines were assessed by flowcytometry, real-time PCR and ELISA, respectively., Results: A significant reduction was observed in the proportion of peripheral Treg cell frequency, and the levels of TGF-β, IL-10 and FoxP3 expression in patients with RRMS. Our data revealed that the frequency of Treg cells (p = .0027), the expression of FoxP3 (p = .0005), TGF-β (p = .0005), and IL-10 (p = .0002) and the secretion levels of the TGF-β (p = .033), and IL-10 (p = .029) in cultured PBMCs are increased in nanocurcumin-treated group compared to placebo group., Conclusion: The results of the current work indicated that nanocurcumin is capable of restoring the frequency and function of Treg cells in MS patients., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In the current study, we aimed to identify nanocurcumin effects on microRNAs (miRNAs) in the peripheral blood of patients with relapsing-remitting multiple sclerosis (RRMS). We intended to investigate the expression pattern of these miRNAs in experimental settings in vivo. The expression levels of the selected 27 miRNAs known to be involved in the regulation of immune responses were analyzed in 50 RRMS patients and 35 healthy controls. The miRNA expression profiles were investigated by quantitative PCR (qPCR) at baseline and after 6 months of nanocurcumin therapy. Our data revealed that the expression of a number of microRNAs including miR-16, miR-17-92, miR-27, miR-29b, miR-126, miR-128, miR-132, miR-155, miR-326, miR-550, miR-15a, miR-19b, miR-106b, miR-320a, miR-363, miR-31, miR-150, and miR-340 is regulated by nanocurcumin. The results of the current work indicate that nanocurcumin is able to restore the expression pattern of dysregulated miRNAs in MS patients. We discovered that some miRNAs are deregulated in untreated patients compared with healthy controls and nanocurcumin-treated patients. This is a new finding that might represent the potential contribution of these miRNAs to MS pathogenesis. Taken together, these data provide novel insights into miRNA-dependent regulation of the function of B and T cells in MS disease and enrich our understanding of the effects mediated by a therapeutic approach that targets B and T cells., (© 2017 Wiley Periodicals, Inc.)

Background: Prostate cancer is known as the most common malignancy in men. Chitosan has generated great interest as a useful biopolymer for the encapsulation of small interfering RNA (siRNA). Due to cationic nature, chitosan is able to efficiently encapsulate siRNA molecules and form nanoparticles. Furthermore, the biocompatible and biodegradable attributes of chitosan have paved the way for its potential application in the in vivo delivery of therapeutic siRNAs. In this study, we aimed to design chitosan/CMD nanoparticles for the efficient encapsulation of the anti-cancer drugs SN38 and Snail-specific siRNA., Methods: Physicochemical characteristics, growth inhibitory properties, and anti-migratory capacities of the dual delivery of SN38-Snail siRNA CMD-chitosan nanoparticles were investigated in prostate cancer cells., Results: Our findings provided evidence for the suggestion that, ChNP-CMD-SN38-siRNA treated cells, the mRNA level of snail decreased from 1.00 to 0.30 (±0.14) and 0.09 (±0.04) after 24h and 48h, respectively. Additionally, the fold induction of E-cadherin and Claudin-1 increased from 1.00 to now 3.12 (±0.62), 3.02 (±0.28) after 24h and 5.6 (±0.91), 4.42 (±0.51) after 48h, respectively. Also, co-delivery of SN38 and Snail-specific siRNA by an appropriate nanocerrier (chitosan nanoparticles) could reduce the viability, proliferation, and migration of PC-3 cells., Conclusions: In conclusion, ChNPs encapsulating SN38 and Snail-specific siRNA may represent huge potential as an effective anti-cancer drug delivery system for the treatment of prostate cancer., (Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.)

CD4 + CD25 + regulatory T (Treg) cells and Th17 cells play important roles in peripheral immunity. Immune responses are main elements in the pathogenesis of ischemic stroke (IS). The contribution of Th17 cells in IS patients has not been proved, and whether the balance of Treg/Th17 cells is changed in IS patients remains unidentified. In the present study, we studied Th17 and Treg cell frequency, cytokine secretion, expression of transcription factors, and microRNAs related to Th17 and Treg cells differentiation, which is compared between IS patients and control group. Thirty patients with IS and 30 individuals as control group were enrolled in this study. The frequency of Th17 and Treg lymphocytes, the expression of transcription factors and microRNAs related to these cells, and the serum levels of associated cytokines were assessed by flow cytometry, real-time PCR, and ELISA, respectively. A significant reduction in proportion of peripheral Treg cell frequency and the levels of TGF-β and FOXP3 expression were observed in patients with IS compared with controls, while the proportions of Th17 were increased dramatically, and these effects were along with increases in the levels of IL-17A and RORγt expression in IS patients. The levels of mir-326 and mir-106b-25 expression were increased in patients with IS. These studies suggest that the increase in proportion of Th17 cells and decrease in Treg cells might contribute to the pathogenesis of IS. Manipulating the balance between Tregs and Th17 cells might be helpful for the treatment of IS.

Here, we investigated the effects of dual delivery of IGF-1R siRNA and doxorubicin by chitosan nanoparticles on viability of A549 lung cancer cells line by utilization of MTT and qRT-PCR. Furthermore apoptosis and migration of treated cells were assessed by Annexin-PI and wound healing assays, respectively. The chitosan nanoparticles had about 176 nm size with zeta potential and polydispersive index about 11 mV and 0.3, respectively. The IGF-1R siRNA had synergistic effect on DOX-induced cytotoxicity and apoptosis in tumour cells. In addition, siRNA/DOX-loaded chitosan nanoparticles could significantly decrease migration and expressions of mmp9, VEGF and STAT3 in A549 cells.

RIF (repeated implantation failure) women with immunologic basis and cellular abnormalities may benefit from intravenous immunoglobulins (IVIG) as an immunomodulator based on different studies. In this study, we evaluated the effect of IVIG on the frequency and function of Th17 and Treg cells, as two important subgroups of CD 4 + T cells in implantation and pregnancy rates. Seventy-two RIF patients with preconception Th1⁄Th2 ratio and natural killer (NK) cells frequency and activity elevation were selected and divided into two groups; 40 out of 72 received IVIG, aspirin, and heparin (anoxaparin) and constituted the treatment group and 32 patients received aspirin and heparin (anoxaparin) and no IVIG and were the control group. Th17, Treg frequency, transcription factors, cytokine gene expression, and cytokine secretion were evaluated by flow cytometry, real-time PCR, and ELISA, respectively. Post-treatment evaluation of the IVIG grouprevealed a significant increase in Treg associated parameters such as Treg frequency (p = 0.0186), Foxp3 (p = 0.0004), and cytokine mRNA levels (IL-10, p = 0.0058 and TGF- β, p = 0.0038), however, in the case of Th17, a significant difference was only observed in a reduction in the RORγt mRNA level (p = 0.0218). In conclusion, IVIG therapy may be a good choice in the treatment of implantation failure in RIF women especially with an immunologic basis, and may improve the implantation and pregnancy rate by affecting immunoregulatory mechanisms such as Tregs., Abbreviations: RIF: repeated implantation failure; IVIG: intravenous immunoglobulin; Th17: T helper 17; Treg: T regulatory; NK cells: natural killer cells; PCR: polymerase chain reaction; ELISA: enzyme-linked immunosorbent assay; RORγt: RAR-related orphan receptor gamma; Foxp3: forkhead box protein P3; IL-17: interleukin-17; LMWH: low-molecular weight heparin; dNK: decidual NK cells.

The receptor tyrosine kinase (RTK) Met is the cell surface receptor for hepatocyte growth factor (HGF) involved in invasive growth programs during embryogenesis and tumorgenesis. There is compelling evidence suggesting important roles for c-Met in colorectal cancer proliferation, migration, invasion, angiogenesis, and survival. Hence, a molecular inhibitor of an extracellular domain of c-Met receptor that blocks c-Met-cell surface interactions could be of great thera-peutic importance. In an attempt to develop molecular inhibitors of c-Met, single chain variable fragment (scFv) phage display libraries Tomlinson I + J against a specific synthetic oligopeptide from the extracellular domain of c-Met receptor were screened; selected scFv were then characterized using various immune techniques. Three c-Met specific scFv (ES1, ES2, and ES3) were selected following five rounds of panning procedures. The scFv showed specific binding to c-Met receptor, and significantly inhibited proliferation responses of a human colorectal carcinoma cell line (HCT-116). Moreover, anti- apoptotic effects of selected scFv antibodies on the HCT-116 cell line were also evaluated using Annexin V/PI assays. The results demonstrated rates of apoptotic cell death of 46.0, 25.5, and 37.8% among these cells were induced by use of ES1, ES2, and ES3, respectively. The results demonstrated ability to successfully isolate/char-acterize specific c-Met scFv that could ultimately have a great therapeutic potential in immuno-therapies against (colorectal) cancers.

Background: Th17 cells and Treg cells have been proposed as new risk factors for recurrent miscarriage (RM). In this study, we investigated the effect of Intravenous immunoglobulin G (IVIG) on the levels and function of Th17 and Treg cells and pregnancy outcome in women with RM., Materials and Methods: 94 pregnant women with RM were enrolled in this study. Blood was drawn at the time of positive pregnancy. On the same day, IVIG 400mg/kg was administered intravenously for 44 patients. 50 other RM patients were included as no IVIG interfering control group. Following the first administration, IVIG was given every 4 weeks through 32 weeks of gestation. Peripheral blood was drawn after the last administration (32 weeks after pregnancy)., Results: IVIG down-regulated Th17 cells population and function and up-regulated Treg cells population and function were significant in the treated group. Pregnancy outcome in IVIG treated subjects was successful in 38 out of 44 RM women (86.3%). However, pregnancy outcome was successful in 21 out of 50 untreated RM women (42%)., Conclusion: Administration of IVIG in RM women with cellular immune cells abnormalities during pregnancy influences Th17/Treg ratio in peripheral blood and enhances Treg and decreases Th17 responses., (Copyright © 2017. Published by Elsevier B.V.)

ABSTACT Wnt/β-catenin signaling pathway through Frizzled receptors has been shown to play a key role in both normal development and tumorigenesis. Overexpression of Wnt pathway genes, such as Fzd7 in several malignancies is well-documented. Therefore, targeting of Fzd7 and its ligand inhibits cancer cells proliferation metastasis. In the present study we isolated single chain variable fragments (scFvs) against Fzd7 receptor using phage display method. Semi-synthetic human naive antibody libraries (Tomlinson I + J) was employed in panning procedure to isolate specific scFv against specific peptide from extracellular domain of Fzd7 receptor. The reactivity and growth inhibition effects of the selected antibodies was evaluated using enzyme-linked immunosorbent assay (ELISA), MTT and annexin V assays, respectively. Seven scFvs reactive to Fzd7 were selected following 4 rounds of panning. The results showed that the selected scFvs inhibits cell growth through apoptosis cell death in a triple negative breast cancer cells, MDA-MB-231. Given that Fzd7 and Wnt pathway plays a critical role in tumor progression, selected blocking scFvs represent significant potential for immunotherapy of breast cancer cells.

Background: Women with elevated natural killer (NK) cell frequency and function during pregnancy, suffer from recurrent pregnancy loss (RPL). In the present study, the possible effect of intravenous immunoglobulin (IVIG) administration on Th1 and Th2 cell frequency, cytokine secretion, and expression of transcription factors is compared between RPL patients and control group., Materials and Methods: Totally, 44 women with a history of RPL (32 women as treated group and 12 as control group) were enrolled in the study. The frequency of Th1 and Th2 lymphocytes, the expression of transcription factors related to these cells and the serum levels of associated cytokines were assessed by flowcytometry, real-time PCR and ELISA, respectively. All, assessments were performed both before and after treatment with IVIG., Results: A significant reduction in Th1 lymphocyte frequency, transcription factor expression and cytokine levels were observed in IVIG-treated group, while all the above parameters indicated a significant increase for Th2 lymphocytes. Th1/Th2 ratio decreased significantly (p value<0.0001) at the end of treatment and 28 out of 32 (87.5%) women in IVIG-treated group had live birth in comparison with 5 out of 12 (41.6%) in untreated group., Conclusion: IVIG administration proves to be an efficient therapeutic strategy which is able to enhance the success rate of pregnancy through a shift in Th2 responses. Furthermore, IVIG presents efficacy for the treatment of reproduction failures especially in subjects with immune cell abnormalities and increased NK cell level and function., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Receptor tyrosine kinase-like orphan receptor (ROR) proteins are a conserved family of tyrosine kinase receptors that function in developmental processes including cell survival, differentiation, cell migration, cell communication, cell polarity, proliferation, metabolism, and angiogenesis. ROR1 has recently been shown to be expressed in various types of cancer cells but not normal cells. Pharmacokinetics and pharmacodynamics of single-chain Fragment variable (scFv) antibodies provide potential therapeutic advantages over whole antibody molecules. In the present study, scFvs against a specific peptide from the extracellular domain of ROR1 were selected using phage display technology. The selected scFvs were further characterized using polyclonal and monoclonal phage enzyme-linked immunosorbent assay (ELISA), soluble monoclonal ELISA, colony PCR, and sequencing. Antiproliferative and apoptotic effects of selected scFv antibodies were also evaluated in lymphoma and myeloma cancer cell lines using MTT and annexin V/PI assays. The results of ELISA indicated specific reactions of the isolated scFvs against the ROR1 peptide. Colony PCR confirmed the presence of full-length V H and Vκ inserts. The percentages of cell growth after 24 h of treatment of cells with individual scFv revealed that the scFv significantly inhibited the growth of the RPMI8226 and chronic lymphocytic leukemia (CLL) cells in comparison with the untreated cells ( p < 0.05). Interestingly, 24-h treatment with specific scFv induced apoptosis cell death in the RPMI8226 and CLL cells. Taken together, our results demonstrate that targeting of ROR1 using peptide-specific scFv can be an effective immunotherapy strategy in hematological malignancies.

Recent genome-wide association studies have documented a number of genetic variants to explain mechanisms underlying autoimmune diseases. However, the precise etiology of autoimmune diseases remains largely unknown. Epigenetic mechanisms like alterations in the post-translational modification of histones and DNA methylation may potentially cause a breakdown of immune tolerance and the perpetuation of autoreactive responses. Recently, several studies both in experimental models and clinical settings proposed that the epigenome may hold the key to a better understanding of autoimmunity initiation and perpetuation. More specifically, data support the impact of epigenetic changes in autoimmune diseases, in some cases based on mechanistical observations. Epigenetic therapy already being employed in hematopoietic malignancies may also be associated with beneficial effects in autoimmune diseases. In this review, we will discuss on what we know and expect about the treatment of autoimmune disease based on epigenetic aberrations., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

The 4-1BB is a surface glycoprotein that pertains to the tumor necrosis factor-receptor family. There is compelling evidence suggesting important roles for 4-1BB in the immune response, including cell activation and proliferation and also cytokine induction. Because of encouraging results of different agonistic monoclonal antibodies against 4-1BB in the treatment of cancer, infectious, and autoimmune diseases, 4-1BB has been suggested as an attractive target for immunotherapy. In this study, single chain variable fragment phage display libraries, Tomlinson I+J, were screened against specific synthetic oligopeptides (peptides I and II) designed from 4-1BB extracellular domain. Five rounds of panning led to selection of four 4-1BB specific single chain variable fragments (PI.12, PI.42, PII.16, and PII.29) which showed specific reaction to relevant peptides in phage enzyme-linked immunosorbent assay. The selected clones were successfully expressed in Escherichia coli Rosetta-gami 2, and their expression was confirmed by western blot analysis. Enzyme-linked immunosorbent assay experiments indicated that these antibodies were able to specifically recognize 4-1BB without any cross-reactivity with other antigens. Flow cytometry analysis demonstrated an acceptable specific binding of the single chain variable fragments to 4-1BB expressed on CCRF-CEM cells, while no binding was observed with an irrelevant antibody. Anti-4-1BB single chain variable fragments enhanced surface CD69 expression and interleukin-2 production in stimulated CCRF-CEM cells which confirmed the agonistic effect of the selected single chain variable fragments. The data from this study have provided a rationale for further experiments involving the biological functions of anti-4-1BB single chain variable fragments in future studies.

Receptor tyrosine kinase-like orphan receptor (ROR1) belongs to one of the families of receptor tyrosine kinases (RTKs). RTKs are involved in the various physiologic cellular functions including proliferation, migration, survival, signaling and differentiation. Several RTKs are deregulated in various cancers implying the targeting potential of these molecules in cancer therapy. ROR1 has recently been shown to be expressed in various types of cancer cells but not in normal adult cells. Hence a molecular inhibitor of extracellular domain of ROR1 that inhibits ROR1-cell surface interaction is of great therapeutic importance. In an attempt to develop molecular inhibitors of ROR1, we screened single chain variable fragment (scFv) phage display libraries, Tomlinson I + J, against one specific synthetic oligopeptide from extracellular domain of ROR1 and selected scFvs were characterized using various immunological techniques. Several ROR1 specific scFvs were selected following five rounds of panning procedure. The scFvs showed specific binding to ROR1 using immunological techniques. Our results demonstrate successful isolation and characterization of specific ROR1 scFvs that may have great therapeutic potential in cancer immunotherapy.

Nanoparticles are widely used to deliver anticancer drugs and inhibit tumor growth without systemic toxicity. Recently, chitosan has received much attention as a functional biopolymer for encapsulation of small interfering RNA (siRNA). Because of cationic nature, chitosan efficiently encapsulate siRNA and forming nanoparticles. Moreover, biocompatible and biodegradable properties represent chitosan as potential candidate for in vivo siRNA delivery. In the present study we designed carboxymethyl dextran (CMD) chitosan nanoparticles (ChNPs) to encapsulate snail siRNA and anticancer drug doxorubicin (DOX). The effect of ChNPs-drug/siRNA on cell growth and Epithelial mesenchymal transition (EMT) gene expression of HCT-116 cell lines were investigated. Furthermore the efficacy of dual agent nanoparticle to induce apoptosis and inhibit migration of colorectal cancer cells were assessed using Annexin-V and wound healing assays, respectively. The results demonstrated that treatment with dual agent nanoparticles led to significant changes of EMT genes (i.e down regulation of MMP-9 and Vimentin and up regulation of E-cadherin), apoptosis cell death and migration inhibition in HCT-116 cells. In conclusion, ChNPs encapsulating DOX and snail siRNA can be considered as an effective anti-cancer drugs delivery system for the treatment of colorectal cancer., (Copyright © 2016 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.)

Insulin-like growth factor I receptor (IGF-IR) is expressed on breast cancer cells and involves in metastasis, survival, and proliferation. Currently, application of IGF-IR-targeting monoclonal antibodies (mAbs), alone or in combination with other drugs, is a promising strategy for breast cancer therapy. Single-chain fragment variable (scFv) antibodies have been introduced as appropriate tools for tumor-targeting purposes because of their advantages over whole antibodies. In the present study, we employed a naïve phage library and isolated scFvs against a specific epitope from extracellular domain of IGF-IR by panning process. The selected scFvs were further characterized using polyclonal and monoclonal phage ELISA, soluble monoclonal ELISA, and colony PCR and sequencing. Antiproliferative and apoptotic effects of selected scFv antibodies on breast cancer cell lines were also evaluated by MTT and Annexin V/PI assays. The results of ELISA indicated specific reactions of the isolated scFvs against the IGF-IR peptide, and analyses of PCR product and sequencing confirmed the presence of full length V H and Vκ inserts. Treatment of MCF7 and SKBR3 cells with anti-IGF-IR scFv led to a significant growth inhibition. The results also showed that scFv treatment significantly augmented trastuzumab growth inhibitory effects on SKBR3 cells. The percentage of the apoptotic MCF7 and SKBR3 cells after 24-h treatment with scFv was 39 and 30.70 %, respectively. Twenty-four-hour treatment with scFv in combination with trastuzumab resulted in 44.75 % apoptosis of SKBR3 cells. Taken together, our results demonstrate that the targeting of IGF-IR by scFv can be an effective strategy in the treatment of breast cancer and provide further evidence for effectiveness of dual targeting of HER2 and IGF-IR in breast cancer therapy.

Leishmania major is the main causal agent of cutaneous leishmaniasis (CL) that remains a serious public health concern in many tropical and subtropical countries. A long-lasting protective vaccine against leishmaniasis remains as a medical unmet need. Lipophosphoglycan 3 (LPG3) is one of the class II LPG genes from HSP90 family involved in the host immune responses. The aim of the present study is to investigate the capability of recombinant LPG3 (rLPG3) to induce Th1, Th2, Th17 responses. The results showed that rLPG3 in moderate and high concentrations significantly induced expression of Th1 lineage-specific transcription factor (T-bet) and cytokine (IFN-γ)(P < 0.05). Moreover, the Th1-stimulating effect of rLPG3 was confirmed by significant induction of IFN-γ secretion from treated T cells (P < 0.01). However, no significant effect of rLPG3 on Th2 and Th17 lineage cells was observed even in high concentration. Our findings demonstrate that rLPG3 induces Th1, but not Th2 and Th17, lineage responses. Further studies are needed to investigate adjuvant properties of rLPG3 for leishmania therapy.

Several studies have been performed to develop effective neutralizing monoclonal antibodies. The Epstein-Barr virus (EBV) can efficiently immortalize B-cells to establish lymphoblastoid cell lines (LCL) and so it has been used extensively for transformation of B-cells to produce and secrete immunoglobulin. The present study addressed the effect of TLR7/8 agonist (R848), feeder cells layer and fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) cell separation methods on the transformation efficiency of antibody-producing memory B-cells. For these studies, the antigen used for analyses of antibody formation was the tetanus neurotoxin (TeNT) derived from Clostridium tetani. The results here showed that employing an HFFF.PI6 feeder cell layer, R848 agonist and FACS-mediated purification of memory B-cells led to increased transformation efficiency. Altogether, the effects of the R848 and the feeder cells provided an efficient method for EBV transformation of human B-cells. Moreover, there was an advantage in using FACS sorting of B-cells over the MACS method in the context of EBV transformation and immortalization of precursors of antigen-specific B-cells.

In spite of specific immune effector mechanisms raised against tumor cells, there are mechanisms employed by the tumor cells to keep them away from immune recognition and elimination; some of these mechanisms have been identified, while others are still poorly understood. Manipulation or augmentation of specific antitumor immune responses are now the preferred approaches for treatment of malignancies, and traditional therapeutic approaches are being replaced by the use of agents which potentiate immune effector mechanisms, broadly called "immunotherapy". Cancer immunotherapy is generally classified into two main classes including active and passive methods. Interventions to augment the immune system of the patient, for example, vaccination or adjuvant therapy, actively promote antitumor effector mechanisms to improve cancer elimination. On the other hand, administration of specific monoclonal antibodies (mAbs) against different tumor antigens and adoptive transfer of genetically-modified specific T cells are currently the most rapidly developing approaches for cancer targeted therapy. In this review, we will discuss the different modalities for active and passive immunotherapy for cancer.

A protective response against tetanus toxin and toxoid demands efficient specific T cell and B cell responses. Tetanus neurotoxin (TeNT), a 150 kDa polypeptide, is the main cause of tetanus disease. TeNT consists of two structurally distinct chains, a 50 kDa N-terminal light (L) and a 100 kDa C-terminal heavy (H) chain. C-terminal heavy (H) chain (fragment C) has two sub-domains named as proximal HCN and carboxy sub-domain or HCC. Beside neural binding property, HCC has been recently found as an immunodominant module of TeNT. In the present study, we investigated the effects of recombinant HCC (rHCC) on the expression of lineage specific transcription factors and secretion of a panel of functional cytokines including IFN-γ, IL-4, and IL-17 from purified human T cells. Our results revealed that T-bet transcript level, as TH1 specific transcription factor, was significantly increased in the cells treated with 10 and 20 µg/ml of rHCC following 48 h treatment(p<0.05). Treated purified human T cells with rHCC showed significant increase in IFN-γ mRNA level and cytokine secretion, but not IL-4 and IL-17, following 48 h treatment. In conclusion, our results showed that treatment of T cells with r HCC resulted in development of Th1 lineage phenotype, which might lead to a specific and protective antibody mediated response against tetanus toxin.

Tetanus is a highly fatal disease caused by tetanus neurotoxin (TeNT) and remains a major threat to human and animal health, despite preventive strategies. TeNT is composed of heavy and light chain linked by a disulfide bond. The antibody response to TeNT is polyclonal and directed to multiple epitopes within both the light and heavy chains, leading to toxin neutralization. This study was undertaken to localize and compare neutralizing epitopes recognized by human and mouse TeNT-specific antibodies at a clonal level. In the present study, 22 murine hybridoma clones and 50 human lymphoblastoid cell lines secreting monoclonal antibodies (mAb) were generated against TeNT. The specificity of these mAb was determined using different recombinant fragments of tetanus toxin. Moreover, this study investigated the in vitro toxin neutralizing activity of these mAb by a ganglioside GT1b assay. The results showed that tetanus toxoid immunization in humans and BALB/c mice induced a vigorous humoral immune response against different fragments of TeNT, particularly the carboxyl-terminal fragment of the heavy chain (known as fragment C). The fragment C-specific human and mouse mAb could largely neutralize TeNT. However, while all fragment C-specific human mAb reacted with the carboxyl-terminal part of this fragment (H(CC)), the majority of the mouse mAb failed to recognize this region. These results suggested that fragment C is the major target for the TeNT neutralizing antibodies, although different epitopes seem to be targeted by human and mouse antibodies.

Leishmaniasis is one of the most common infectious diseases transmitted by an obligate intracellular genus Leishmania. As there is no efficient vaccination strategy for leishmaniasis, new immunostimulatory components may enhance protective immune responses against this parasite. Lipophosphoglycan 3 (LPG3) is an essential protein required for LPG assembling. In this study, the ability of recombinant LPG3 (rLPG) and its fragments to activate isolated healthy human T-cells and cytokine secretion was evaluated in vitro. The results showed that rLPG3 and its N-terminal fragment (rNT-LPG3) enhanced expression of CD69 on the surface of T-cells and promoted differentiation of CD4(+) T-lymphocytes toward a T-helper 1 (T(H)1) phenotype, in part, through up-regulation of interferon (IFN)-γ expression in a TLR2-independent manner. These results indicated the protective effects of LPG3 (particularly NT-LPG3 fragment) as a potent immunostimulatory component of leishmania in vaccination against leishmaniasis. Further investigations in in vivo assays are clearly warranted.

Background: Tetanus neurotoxin (TeNT) is composed of a light (LC) and heavy chain (HC) polypeptides, released by anaerobic bacterium Clostridium tetani and can cause fatal life-threatening infectious disease. Toxin HC and LC modules represents receptor binding and zinc metalloprotease activity, respectively. The passive administration of animal-derived antibodies against tetanus toxin has been considered as the mainstay therapy for years. However, this treatment is associated with several adverse effects due to the presence of anti-isotype antibodies., Objective: In the present study, we have produced the fully human single chain antibody fragments (HuScFv) from two human antibody phage display libraries., Material and Methods: Twenty-four different HuscFvs were isolated from two anti TeNT immune libraries. Our produced human ScFv (HuScFv) were converted to IgG platform and analyzed regarding their specific reactivity to TeNT., Results: All of the selected scFvs have the same VL but different VH. Three HuscFvs from the first library (TTX15, 51, 75) and two HuscFvs from the second library (TTX16, 20) were chosen to convert to IgG1 using pOptiVEC and pcDNA3.3 systems. Production of IgG1 from transfected DG44 and binding capacity of them to tetanus toxin and toxoid were measured by ELISA. ELISA results showed no detectable production of TTX16 and TTX20 IgG1. Although, TTX51 and TTX75 were converted and produced as IgG1, no reactivity to tetanus toxin and toxoid was observed. However, TTX15 was successfully produced as whole IgG1 platform with reactivity to both tetanus toxin and toxoid. The latter would be an appropriate replacement for conventional polyclonal antibodies if would meet the further characterization including specificity determination, affinity measurement and toxin neutralizing assays., Conclusion: Our results demonstrated production of functional IgG1 derived from TTX15 scFv and might be an appropriate replacement for polyclonal Tetabulin but it needs further characterization.

Kawasaki disease (KD) is an acute febrile systemic vasculitis of childhood characterized by elevated levels of inflammatory mediators at the acute stage. High-dose intravenous immunoglobulin (IVIG) is well accepted as a conventional therapy for KD. The aim of the present study was to determine the expression level of Toll like receptors (TLRs) and their corresponding signaling mediators in PBMCs of IVIG-treated KD patients. TLR2, 3, 9 and signaling mediators, MyD88 and TRIF transcript levels were determined in PBMCs from 31 KD patients, before (acute phase), 2 weeks later (sub-acute phase) and 6 weeks later (convalescent phase) of IVIG therapy using real time PCR. The mean age of the patients was 3.6 years and 65% of subjects were male and 35% were female. 20 age-matched irrelevant febrile patients and 20 healthy subjects were included as control groups. Elevated levels of TLR2, MyD88, and TRIF gene transcripts were observed in the PBMCs at acute phase of untreated KD patients in compression with normal subjects. IVIG therapy resulted in significant decrease in TLR2, 3 and 9 (60-90%) as well as MyD88 and TRIF (60-70%) transcripts following 2 and 6 weeks. With Regard to significant up-regulation of MyD88 and TRIF at the acute phase of KD, our findings suggest TLR signaling pathway potential in KD pathogenesis and may also support the assumption of an infectious background in KD. Down-regulation of TLR members and corresponding mediators in IVIG treated patient suggest general TLR pathway suppression as a novel anti-inflammatory mechanism of IVIG.

Overexpression of IL-25 receptor (IL-25R) on the surface of malignant, but not normal, breast epithelial cells contributes to tumorigenic potential of breast cancer cells. IL-25/IL-25R binding results in specific apoptosis in breast cancer cells. In this study, the inhibitory effects of anti-IL-25R scFv antibodies on three breast cancer cells were evaluated. Panning process was performed on a phage library to isolate scFvs against two specific epitopes of IL25R. The reactivities of scFvs were assessed using phage ELISA. Cell binding capacity of the selected scFvs on breast cancer cells was analyzed using flow cytometry. Anti-proliferative and apoptotic effects of scFvs were evaluated by MTT, Annexin V/PI and quantitative caspase 3 activity assays. Two scFvs with frequencies of 47% and 68% were selected against peptides I and II, respectively. Phage ELISA demonstrated the specific reactions of the scFvs against the corresponding peptides. The scFvs against peptides I and II bound to 14% and 21% of MDA-231, 28% and 32% of MCF7, and 21% and 30% of SKBR3 cells, respectively. Treatment of the breast cancer cells with IL-25 and two anti-IL-25R scFvs resulted in significant inhibition of the cell growth in these cell compared to that in IL-25R negative Raji cells. The results also demonstrated 66% and 70% apoptosis cell death and 15.5 and 17 fold increases in caspase- 3 activity in SKBR3 cells induced by scFvs I and II, respectively. Our findings suggest the targeting of IL-25R by scFvs as a new effective strategy in breast cancer immunotherapy.