CbpM and CbpG of Streptococcus Pneumoniae Elicit a High Protection in Mice Challenged with a Serotype 19F Pneumococcus

Among many pneumococcal antigens, choline-binding proteins (CPBs) display a high immunogenicity in animal models. This study aims to determine the immunogenicity of CbpM, CbpG and CbpL proteins of Streptococcus pneumoniae in a mice model. The genes were cloned into pET21a expression vector and the recombinant proteins were produced. Mice were immunized with the purified recombinant proteins. Subsequently, the mice were challenged with S. pneumoniae ATCC 49619 (2×106 CFU) and their survival and bacterial clearances were followed 24 hours after infection. The antibody responses of the mice were determined by ELISA assay. The opsonophagocytosis assay was performed using rabbit's sera. Passive immunization was carried out using two doses of anti-CbPs antibodies. Finally, these mice were  experimentally infected with virulent bacteria and the protective effects of two doses of 10 and 100 µg/mL by monitoring the survival rate and bacterial clearance were determined at 2, 3 and 7 days after bacterial challenge. The mice actively immunized with CbpM, CbpG and CbpL recombinant proteins showed survival rate of 100%, 85% and 75%, respectively. The survival rates among passively immunized mice groups which received 100 µg/mL dose of anti-CbpM, anti-CbpG and anti- CbpL were 50%, 50% and 25%, respectively. The rates of opsonization with rabbit's antibodies against CbpM, CbpG, and CbpL  at 100 µg/mL doses was 45.6%, 14.7% and 82.3%, and at 10 µg/mL was 12.9%, 12.2% and 9.35%, respectively. Our findings suggest that the recombinant proteins particularly CbpM and CbpG can protect the mice against pneumococcus19F serotype and effectively induce a protective antibody response. Thus, CbpG and CbpM proteins might be used as suitable vaccine candidate in pneumococcal vaccine formulations.

Differential Effects of Inhibitory and Stimulatory Anti-HER2 Monoclonal Antibodies on AKT/ERK Signaling Pathways

Objective:

Homo- and heterodimerization of the receptor tyrosine kinase HER2 hyperactivate several downstream signaling pathways, leading to uncontrolled growth and proliferation of tumor cells. Anti-HER2 monoclonal antibodies (mAbs) may induce different effects on HER2 dimerization and signaling.

Methods:

The effect of two inhibitory (2A8, 1T0) and one stimulatory (1H9) anti-HER2 mAbs either alone or in combination with trastuzumab was investigated on AKT and ERK signaling pathways and HER2 degradation in a human breast cancer cell line (BT-474) by Western blotting.

Result:

While 1H9 mAb had no significant effect on AKT and ERK signaling pathways, 1T0 and 2A8 mAbs inhibited phosphorylation of both pathways. Combination of 1T0 mAb with trastuzumab resulted in significant synergistic inhibition of both pathways and HER2 degradation, much more potently than the combination of trastuzumab and pertuzumab.

Conclusion:

Our data indicate that anti-HER2 mAbs may induce different signaling pathways depending on their effect on tumor cell growth and proliferation. The significant inhibition of ERK and AKT phosphorylation by 1T0 alone or particularly in combination with trastuzumab suggests its potential therapeutic application for targeted immunotherapy of HER2 overexpressing malignancies.

Quantum Dot-labeled Tags Improve Minimal Detection Limit of CA125 in Ovarian Cancer Cells and Tissues

In recent years, a lot of attention has been paid to quantum dot (QD) nanoparticles as fluorescent sensors for sensitive and accurate detection of cancer biomarkers. Here, using a homemade specific monoclonal antibody against CA125 and QD525- or FITC-labeled probes, expression of this marker in an ovarian cancer cell line and cancer tissues were traced and optical properties of fluorophores were compared qualitatively and quantitatively. Our results clearly showed that besides lower background and exceptionally higher photobleaching resistance, QD525 exhibited higher fluorescent intensity for both ovarian cancer cell and tissues at different exposure times (p<0.0001) and excitation filter sets (p<0.0001) exemplified by significantly higher staining index (p<0.016). More importantly, the FITC-labeled probe detected antigen-antibody complex at minimum concentration of 0.3 mg/mL of anti-CA125, while reactivity limit decreased to 0.078 mg/mL of anti-CA125 when QD525-labeled probe was applied showing four times higher reactivity level of QD525 probe compared to the same probe labeled with FITC. Based on our results, it seems that QDs are inimitable tags for sensitive detection and localization of ovarian cancer micrometastasis and molecular demarcation of cancer tissues in surgical practice, which subsequently figure out accurate therapeutic approaches.

Design and Synthesis of a Biocompatible 1D Coordination Polymer as Anti-Breast Cancer Drug Carrier, 5-Fu: In Vitro and in Vivo Studies

Designable coordination polymers with suitable chemical diversities and biocompatible structures have been proposed as a promising class of vehicles for drug delivery systems. Here, we hydrothermally synthesized a novel one-dimensional (1D) coordination polymer, [Zn(H₂O)₆K₂(H₂BTC)₂(H₂O)₄](H₂BTC)₂·2H₂O, where H₃BTC = benzene-1,3,5-tricarboxylic acid (trimesic acid), cp.1. As the hydrogen bonds stabilized 1D chains in three dimensions, the cp.1 could be a good candidate for delivering small-molecule chemotherapeutics such as 5-fluorouracil (5-Fu). The synthesized cp.1 showed a remarkable 5-Fu loading of 66% with encapsulation efficiency of 98% and almost complete release process. The 5-Fu-loaded cp.1 displayed a time-dependent cytotoxicity effect against breast cancer cell lines MCF-7 and 4T1. The cellular uptake of cp.1 particles was investigated via confocal laser scanning microscopy using fluorescein isothiocyanate and LysoTracker Red staining. Furthermore, the in vivo antitumor impact of 5-Fu-loaded cp.1 was studied on 4T1 breast cancer BALB/c mice model. The intratumor treatment of 5-Fu-loaded cp.1 demonstrated beneficial antitumor efficacy by postponing tumor growth. These results suggest that the 5-Fu-loaded cp.1 microparticles with a great locoregional delivery can be efficient anticancer drug carriers for further clinical treatments.

All-trans retinoic acid in combination with sodium butyrate enhances specific monoclonal antibody productivity in recombinant CHO cell line

The effects of all-trans retinoic acid (RA) and sodium butyrate (NaBu) on growth, viability and antibody production of two types of transfected Chinese hamster ovary cell lines (CHO-K1 and CHO-S) were investigated using a batch mode cell culture. By adding 0.5 mM NaBu in the CHO-K1 cell culture, the cell specific productivity (Q_p) and antibody concentration increased by five- and threefold, respectively. The optimal concentration of RA was 100 nM which resulted in twofold increase in antibody production. In a combination model, RA applied at early growth phase of CHO-K1 cells followed by addition of NaBu with lowering culture temperature at the end of stationary phase resulted in two- and threefold increase in Q_p and final antibody concentration, respectively. The latter strategy was also applied on suspended CHO-S cells with enhanced Q_p and antibody concentration, but to a lesser extent than the CHO-K1 cells. In conclusion, our results demonstrate that the addition of RA and NaBu along with lowering the culture temperature can increase cell culture period as well as Q_p and the final concentration of recombinant monoclonal antibody in both CHO-K1 and CHO-S cells without any significant change in binding affinity of the mAb.

Diminished Frequency of Menstrual and Peripheral Blood NKT-Like Cells in Patients With Unexplained Recurrent Spontaneous Abortion and Infertile Women

Systemic monitoring of immune system may not precisely outline the local immune status in the uterus. This survey is a continuation of our previous studies on potential usefulness of menstrual blood (MB) immunophenotyping as a tool for investigation of immunological disturbances in pregnancy-related disorders. Peripheral blood (PB) and MB from healthy fertile (n = 15), unexplained recurrent spontaneous abortion (URSA; n = 15), and unexplained infertile women (n = 8) were collected simultaneously in the second day of their menstrual cycle and frequency of natural killer T (NKT)-like cell subpopulations were assessed by flow cytometry. Menstrual blood of all experimental groups contained higher percentage of TCRαβ⁺, CD45RO⁺, and CD16^- NKT-like cells compared to corresponding PB. Frequency of MB NKT-like cells in unexplained infertile participants was lower than fertile and URSA groups. Compared to normal participants, patients with URSA had lower frequency of PB TCRαβ⁺ and higher CD16⁺, while in infertile woman frequencies of PB CD45RO⁺, CD45RO^-, CD16^-, IL17⁺, and MB CD45RO⁺ NKT-like cells were lower. Although, PB and MB seemingly have the same histological nature, our results showed that MB contained different composition of NKT-like subsets with different cytokine profiles and could be viewed as one potential biological sample for evaluation of patients with infertility and URSA.

Immunization with HER2 extracellular subdomain proteins induces cellular response and tumor growth inhibition in mice

AIM

We investigated cellular and protective immune responses in mice vaccinated with recombinant HER2 extracellular subdomains.

MATERIALS & METHODS

Balb/C mice were immunized with recombinant full HER2 extracellular domain and subdomain proteins. Humoral and cellular immune response and antitumor effect was evaluated using a syngeneic mice tumor model.

RESULTS

All recombinant proteins induced secretion of IL-4 and particularly IFN-γ and IL-17 cytokines. Challenging of immunized mice with stable 4T1-HER2 transfected cells resulted in partial but significant tumor growth inhibition in all groups of mice particularly those immunized with fHER2-ECD together with CPG.

CONCLUSION

Our results suggest that the recombinant HER2-ECD subdomains induce mainly Th1 and Th17 responses, which seem to contribute to tumor growth inhibition in syngeneic mice.

Rearing and Biology of Phlebotomus sergenti, the Main Vector of Anthroponotic Cutaneous Leishmaniasis in Iran

BACKGROUND

Establishment of sand flies laboratory colonies is essential to understand various biological aspects of Phlebotominae sand flies. The aims of the current study were to establish the colony of Phlebotomus sergenti Parrot (1917), the main vector of anthroponotic cutaneous leishmaniasis in old world, and to study biological parameters of this species.

METHODS

The sand flies were reared at 26-28 °C temperature, 14:10 (light: dark) photoperiod and 70-80% relative humidity. Larval diet was a composted mixture of rabbit faces and rabbit pellets which is prepared through a special process. First to fifth generations of P. sergenti were used to define biological parameters.

RESULTS

Results showed that, P. sergenti blood feeding percentage were 42% on chicken, 21% on BALB/c and 37% on golden hamster. Average time of blood digestion, egg incubation, 1^st instar larva, pupa and adult emerging was recorded at 3.4, 8.7, 15, 33.3 and 41.2 days after blood feeding, respectively. Mean number of laid eggs was 55.1 and retained eggs were 35 per a female. Fecundity and production rate were 61.6%, and 42.2% respectively. Average longevity recorded at 15.2 days for females and 14.8 days for males.

CONCLUSION

Colony of P. sergenti has been established for the first time in Iran. Average interval time from egg to adult of this species was 32.5 days. Chicken and golden hamster were recommended as a blood source for colony initiation and routine blood feeding, respectively.

Generation and Characterization of Siglec-F-Specific Monoclonal Antibodies

Siglec-F (SF) is a surface glycoprotein expressed by mouse eosinophils and induces caspase- and mitochondria-dependent apoptosis after engagement with its cognate ligand or specific antibodies. This targeting eosinophils by monoclonal antibodies may help diverse diseases associated with increased frequency of eosinophils including allergy and asthma. In this paper, production of murine and rat monoclonal antibodies (mAbs) against Siglec-F has been addressed. Balb/c mice were immunized with siglec-F1 (SF1) and siglec-F2 (SF2) synthetic peptides conjugated to a carrier protein. Rats were immunized with Chinese hamster ovary CHO cells overexpressing Siglec-F (CHO-SF) or with Siglec-F-human immunoglobulin FC fusion protein (CHO-SF-Ig). Hybridomas were produced by standard protocol and screened for their reactivity by enzyme-linked immunosorbent assay (ELISA), western blotting (WB), and flow cytometry. In parallel, polyclonal antibodies were generated in New Zealand White rabbits immunized with SF1 and SF2 peptides. Three mouse and three rat mAbs were generated against synthetic peptides and SF-Ig, respectively. All mouse monoclonal and rabbit polyclonal antibodies reacted well with immunizing molecules in ELISA and detected specific band of Siglec-F in WB. However, they failed to detect native molecule in flow cytometry analysis. Quite the contrary, rat mAbs did not reacted with the denatured protein in WB, instead exhibited significant reactivity with CHO-SF cells in flow cytometry. Based on the heavily glycosylated nature of Siglec-F, it seems that generation of anti-SF antibodies able to detect native protein needs a properly folded molecule for immunization. Monoclonal antibodies reported here are invaluable tools for studying linear and conformation epitopes of SF and tracing mouse eosinophils.

Epitope Mapping of Human HER2 Specific Mouse Monoclonal Antibodies Using Recombinant Extracellular Subdomains

Background: Human epidermal growth factor receptor 2 (HER2) is overexpressed in several human malignancies and numerous studies have indicated that it plays important roles in the development and maintenance of the malignant phenotype. Targeting of HER2 molecules with monoclonal antibodies (mAbs) is a promising therapeutic approach. However, anti-HER2 mAbs affect cancer cells differently, depending on the distinct epitopes which are the targets. Methods: Reactivity of a panel of 8 mouse anti-HER2 mAbs was investigated by ELISA and Western blotting using different subdomains of the extracellular domain (ECD) of HER2. All subdomains, including I, II, III, IV, I+II, III+IV and full HER2-ECD were constructed and expressed in CHO cells. Cross-reactivity of the mAbs with other members of the human HER family and Cynomolgus HER2 was also studied by ELISA. The mAbs were also tested by immunohistochemistry (IHC) using HER2 positive breast cancer tissues. Results: Our results demonstrated that 3 out of 8 mAbs detected conformational epitopes (1T0, 2A8 and 1B5), while 5 mAbs identified linear epitopes (1F2, 1H9, 4C7, 1H6 and 2A9). Three of the mAbs recognized subdomain I, one reacted with subdomain I+II, 2 recognized either subdomain III or IV and 2 recognized subdomain III+IV. However, none of our mAbs recognized the subdomain II alone. The mAbs displayed either inhibitory or stimulatory effects on HER2-overexpressing tumor cells and did not react with other members of the human HER family. The pattern of IHC results implied better reactivity of the mAbs recognizing linear epitopes. Conclusions: Our findings suggest that paired subdomains of HER2 are essential for mapping of mAbs recognizing conformational epitopes. Moreover, there seems to be no association between subdomain specificity and antitumor activity of our anti-HER2 mAbs.

Hersintuzumab: A novel humanized anti-HER2 monoclonal antibody induces potent tumor growth inhibition

Humanized monoclonal antibodies (mAbs) against HER2 including trastuzumab and pertuzumab are widely used to treat HER2 overexpressing metastatic breast cancers. These two mAbs recognize distinct epitopes on HER2 and their combination induces a more potent blockade of HER2 signaling than trastuzumab alone. Recently, we have reported characterization of a new chimeric mAb (c-1T0) which binds to an epitope different from that recognized by trastuzumab and significantly inhibits proliferation of HER2 overexpressing tumor cells. Here, we describe humanization of this mAb by grafting all six complementarity determining regions (CDRs) onto human variable germline genes. Humanized VH and VL sequences were synthesized and ligated to human γ1 and κ constant region genes using splice overlap extension (SOE) PCR. Subsequently, the humanized antibody designated hersintuzumab was expressed and characterized by ELISA, Western blot and flow cytometry. The purified humanized mAb binds to recombinant HER2 and HER2-overexpressing tumor cells with an affinity comparable with the chimeric and parental mouse mAbs. It recognizes an epitope distinct from those recognized by trastuzumab and pertuzumab. Binding of hersintuzumab to HER2 overexpressing tumor cells induces G1 cell cycle arrest, inhibition of ERK and AKT signaling pathways and growth inhibition. Moreover, hersintuzumab could induce antibody-dependent cell cytotoxicity (ADCC) on BT-474 cells. This new humanized mAb is a potentially valuable tool for single or combination breast cancer therapy.

Investigating the Antiangiogenic, Anti-drug Resistance and Apoptotic Effects of Soy Isoflavone Extract Alone or in Combination with Docetaxel on Murine 4T1 Breast Tumor Model

BACKGROUND

One major concern in the treatment of cancer patients during chemotherapy is drug resistance. Here we investigated the effects of soy isoflavone extracts alone or in combination with Docetaxel on the drug resistance, angiogenesis, apoptosis, and tumor volume in mouse 4T1 breast tumor model.

METHODS

Sixty female BALB/c mice were randomly divided into 4 groups: control, dietary soy isoflavone extract [Iso, 100 mg/kg diet (0.01%)], Docetaxel (10 mg/kg) injection, and the combination of dietary soy isoflavone extract and intravenous Docetaxel injection (Docetaxel + Iso). One week after the third injection, the breast tumors of eight mice from each group were excised to analyze NF-κBp65' vascular endothelial growth factor receptor-2 (VEGFR2) and Pgp gene and protein expressions and the other seven mice were monitored for survival rate analysis until they died.

RESULTS

NF-κBp65 gene and protein expressions were significantly lower in the Docetaxel + Iso group in comparison with that of the Docetaxel group. VEGFR2 protein expression in the Docetaxel + Iso and Iso groups was significantly lower than that of the Docetaxel group.

CONCLUSION

These findings may indicate that the combined use of isoflavone extracts together with chemotherapeutic agents has more efficient anti-carcinogenic effects than their individual use.

NanoMIL-100(Fe) containing docetaxel for breast cancer therapy

Metal-organic frameworks, such as MIL-100, have been recently introduced as promising drug carriers due to their notable characteristics such as stability, biocompatibility and owning large porosity which may admit a broad range of drugs with different molecular sizes. In this study, we firstly proposed an accessible top-down approach using ultrasound method to prepare nanoMIL-100 and secondly, evaluated its potentials as an anticancer nanocarrier. This is the first report that docetaxel (DTX) as a highly hydrophobic anticancer drug was encapsulated in nanoMIL-100 with the drug payload of 57.2 wt%. Characterizations of the prepared nanoMIL-100 and DTX-loaded nanoMIL-100 were performed by PXRD, FT-IR, N₂ adsorption, DLS and FE-SEM. Moreover, the drug loading and release processes were quantified by HPLC. The in vitro release of DTX from the prepared nanocarrier was investigated in two pH values, 7.4 and 5.5. The toxic effect of DTX-loaded nanoMIL-100 was examined on human breast cancer cell line, MCF-7, and a significant decrease was observed in IC₅₀ value (0.198 μg/mL) at the first 24 h in comparison with the free drug (4.9908 μg/mL). This nanocarrier may, thus offer promising potentials as a novel cytotoxic drug delivery system.

Polymorphisms in the Estrogen Receptor Beta Gene and the Risk of Unexplained Recurrent Spontaneous Abortion

BACKGROUND

Recurrent Spontaneous Abortion (RSA) is caused by multiple genetic and non-genetic factors. Around 50% of the RSA cases have no known etiology and are considered as Unexplained RSA (URSA). Estrogens, via binding to their receptors, play an important role in female reproduction. This study aimed to investigate whether single nucleotide polymorphisms (SNPs; +1082G/A, +1730G/A and rs1256030 C/T) in the estrogen receptor beta (ESR2) gene are associated with susceptibility to URSA in a population of Iranian women.

METHODS

In this case-control study, the study groups consisted of 240 subjects with a history of URSA and 102 fertile women as controls. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were measured on day 2-3 of menstrual cycle. Two functional SNPs, +1082G/A (a silent mutation in exon 5) and +1730G/A (3' untranslated region of the exon 8), and one intron, rs1256030C/T, in the ESR2 gene were genotyped, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

Serum levels of LH were significantly increased in URSA women. No significant differences in distribution of +1082G/A, +1730G/A and rs1256030C/T between URSA and control groups were observed.

CONCLUSION

Our findings suggest that the studied SNPs on ESR2 gene may not be associated with URSA.

Production and Characterization of a Novel Monoclonal Antibody Against Human Sortilin

Sortilin, as a member of Vps10p-domain sorting receptor family, is overexpressed in a number of malignancies, including ovarian carcinoma. Antibodies against sortilin may contribute to further clarification of sortilin functional activities in signal transduction, intracellular sorting of proteins, and endocytosis. The aim of this study was to produce a monoclonal antibody against a synthetic peptide derived from extracellular N-terminal region of sortilin to be used as a tool for investigating sortilin characteristics in ovarian carcinoma. A synthetic peptide derived from the last 50 amino acids of extracellular domain of sortilin protein was selected and conjugated to keyhole limpet hemocyanin and used to immunize mice. The anti-sortilin monoclonal antibody (MAb), clone 2D8, was purified from supernatant of final hybridoma clone using peptide-affinity chromatography column. Reactivity of antibody with the immunizing peptide was assessed in ELISA. Furthermore, flow cytometry and Western blot analyses were used to investigate the reactivity of antibody with its target in a panel of ovarian carcinoma cell lines or tissues. MAb 2D8 was able to recognize the coated immunizing peptide in ELISA and detect its protein target, sortilin, in flow cytometry and Western blot analyses. The achieved data suggest that the developed monoclonal antibody may be applicable as a research tool for detection of sortilin protein in Western blot as well as flow cytometry tests.

Localization of immunodominant epitopes within the "a" determinant of hepatitis B surface antigen using monoclonal antibodies

The common "a" determinant is the major immunodominant region of hepatitis B surface antigen (HBsAg) shared by all serotypes and genotypes of hepatitis B virus (HBV). Antibodies against this region are thought to confer protection against HBV and are essential for viral clearance. Mutations within the "a" determinant may lead to conformational changes in this region, which can affect the binding of neutralizing antibodies. There is an increasing concern about identification and control of mutant viruses which is possible by comprehensive structural investigation of the epitopes located within this region. Anti-HBs monoclonal antibodies (mAbs) against different epitopes of HBsAg are a promising tool to meet this goal. In the present study, 19 anti-HBs mAbs were employed to map epitopes localized within the "a" determinant, using a panel of recombinant mutant HBsAgs. The topology of the epitopes was analyzed by competitive enzyme-linked immunosorbent assay (ELISA). Our results indicate that all of the mAbs seem to recognize epitopes within or in the vicinity of the "a" determinant of HBsAg. Different patterns of binding with mutant forms were observed with different mAbs. Amino acid substitutions at positions 123, 126, 129, 144, and 145 dramatically reduced the reactivity of antibodies with HBsAg. The T123N mutation had the largest impact on antibody binding to HBsAg. The reactivity pattern of our panel of mAbs with mutant forms of HBsAg could have important clinical implications for immunoscreening, diagnosis of HBV infection, design of a new generation of recombinant HB vaccines, and immunoprophylaxis of HBV infection as an alternative to therapy with hepatitis B immune globulin (HBIG).

Differential expression profiles of the salivary proteins SP15 and SP44 from Phlebotomus papatasi

Background

Sand fly saliva has been shown to help parasite establishment and to induce immune responses in vertebrate hosts. In the current study, we investigated the pattern of expression of two Phlebotomus papatasi salivary transcripts in specific physiological and seasonal conditions at a hyperendemic area of zoonotic cutaneous leishmaniasis (ZCL) in Iran.

Methods

Sand flies were collected during 2012–2013, and grouped according to physiological stages such as unfed, fed, semi-gravid, gravid, parous, nulliparous, infected or non-infected with Leishmania major and also based on the season in which they were collected. Quantitative Real-Time PCR was applied for assessment of the expression of two relevant salivary transcripts, PpSP15 and PpSP44, associated to protection from and exacerbation of ZCL, respectively.

Results

The expression of PpSP15 and PpSP44 transcripts was significantly up-regulated (1.74 and 1.4 folds, respectively) in blood fed compared to unfed flies. Among four groups of fed, unfed, semi-gravid and gravid flies, the lowest levels of PpSP15 and PpSP44 expression were observed in gravid flies. Additionally, the expression levels of both PpSP15 and PpSP44 transcripts in P. papatasi collected during summer were significantly up-regulated (3.7 and 4.4 folds, respectively) compared to spring collections. In addition, the PpSP15 transcript exhibited a significant up-regulation (P < 0.05) in non-infected flies compared to those infected with L. major.

Conclusions

This study contributes to our knowledge of the differential expression of salivary genes among different groups within a P. papatasi population under natural field conditions. Cutaneous and visceral leishmaniasis are of public health importance in many parts of Iran and neighbouring countries where P. papatasi is the proven and dominant sand fly vector for ZCL, the most prevalent and endemic form of the disease in Iran. Therefore, the current study could be helpful in understanding the influence of salivary genes on Leishmania transmission by phlebotomine sand flies. Our findings demonstrate the differential expression of salivary transcripts under various physiological conditions potentially influencing the sand fly capacity for parasite transmission as well as the outcome of disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1633-z) contains supplementary material, which is available to authorized users.

A shift in the balance of T17 and Treg cells in menstrual blood of women with unexplained recurrent spontaneous abortion

To determine usefulness of menstrual blood for assessment of differential frequency of T cell subsets, peripheral blood (PB) and menstrual blood (MB) from healthy fertile (n=15), unexplained recurrent spontaneous abortion (URSA) women (n=15) and unexplained infertile women (n=8) were collected in the second day of menstrual bleeding. Frequency of T cell subsets was measured by flow cytometry. URSA and unexplained infertile patients had higher frequency of TCRαβ(+)CD3(+)CD56(-) and CD45RO(+) T cells as well as CD45RO(+)/CD45RO(-) ratio in PB as compared to MB. Frequency of CD3(+)TCRγδ(+) cells in PB of unexplained infertile and MB of URSA patients were significantly lower than that in fertile group. In all groups MB contained higher percentage of CD4(+)CD25(+)Foxp3(+) regulatory and lower percentages of CD16(+) T cells compared to PB. T17 cells (CD3(+)CD56(-)IL-17(+)) was found to be significantly higher in MB of only fertile and unexplained infertile subjects and not URSA patients in comparison with PB. Compared to PB, only fertile women had higher T17:Treg ratio in their MB. URSA women had significantly lower MB T17 cells and T17:Treg ratio compared to those in fertile and unexplained infertile women. Based on the findings presented here, we speculate that MB has its own unique immune milieu which is not solely continuation of the immune environment of secretory endometrium. Indeed, immunophenotyping of MB immune cells could potentially be a useful tool for investigation of immunological disturbances in pregnancy-related disorders.

Production and characterization of a peptide-based monoclonal antibody against CD44 variant 6

The gene that codes for the CD44 family members consists of 20 exons, nine of which encode the standard form of the molecule. The other exons can be inserted in various combinations into the membrane proximal region of the extracellular domain of the protein, giving rise to variant isoforms (CD44v). CD44 variants, especially the CD44v6, have been reported to regulate tumor invasion, progression, and metastasis of carcinomas. Producing a high affinity monoclonal antibody against human CD44v6 provides a powerful tool to monitor and trace CD44v6 function in different biological fluids. In this study, a synthetic peptide from CD44v6 was conjugated to keyhole limpet hemocyanin (KLH) and injected into BALB/c mice. Splenocytes from the immunized mice were fused with murine SP2/0 myeloma cells followed by selection of antibody producing hybridoma cells. After screening of hybridoma colonies by ELISA, high affinity antibodies were selected and purified by affinity chromatography. Western blot, immunocytochemistry, and flow cytometry experiments were used to characterize the antibodies. Six stable hybridoma cell lines, designated as 1H1, 1H2, 2A12, 2G11, 3H3, and 3H7, were obtained. Flow cytometry and immunocytochemistry results showed that the new monoclonal antibodies recognized CD44v6 on the cell surface. This novel panel of anti-CD44v6 antibodies has the potential for investigating the role of CD44v6 in cancer pathogenesis.

Spontaneous Immunity Against the Receptor Tyrosine Kinase ROR1 in Patients with Chronic Lymphocytic Leukemia

Background

ROR1 is a receptor tyrosine kinase expressed in chronic lymphocytic leukemia (CLL) and several other malignancies but absent in most adult normal tissues. ROR1 is considered an onco-fetal antigen. In the present study we analysed spontaneous humoral and cellular immunity against ROR1 in CLL patients.

Materials and Methods

Antibodies against ROR1 were analysed in 23 patients and 20 healthy donors by ELISA and Western blot. Purified serum IgG from patients was tested for cytotoxicity against CLL cells using the MTT viability assay. A cellular immune response against ROR1 derived HLA-A2 restricted 9 aa and 16 aa long peptides were analysed using peptide loaded dendritic cells co-cultured with autologous T cells from CLL patients (n = 9) and healthy donors (n = 6). IFN-γ, IL-5 and IL-17A-secreting T cells were assessed by ELISPOT and a proliferative response using a H3-thymidine incorporation assay.

Results

The majority of CLL patients had antibodies against ROR1. Significantly higher titers of anti-ROR1 antibodies were noted in patients with non-progressive as compared to progressive disease. The extracellular membrane-close ROR1 KNG domain seemed to be an immunodominant epitope. Ten patients with high titers of anti-ROR1 binding antibodies were tested for cytotoxicity. Five of those had cytotoxic anti-ROR1 antibodies against CLL cells. ROR1-specific IFN-γ and IL-17A producing T cells could be detected in CLL patients, preferentially in non-progressive as compared to patients with progressive disease (p<0.05).

Conclusion

ROR1 seemed to spontaneously induce a humoral as well as a T cell response in CLL patients. The data support the notion that ROR1 might be a specific neo-antigen and may serve as a target for immunotherapy.

Restricted antibody response to Bordetella pertussis filamentous hemagglutinin induced by whole-cell and acellular pertussis vaccines

BACKGROUND

Filamentous hemagglutinin (FHA) is a principal virulence factor, an important immunogenic antigen of Bordetella pertussis, and a major component of many acellular pertussis vaccines. In the present study, the human antibody response to different regions of FHA was determined in healthy children and adults vaccinated with either whole-cell or acellular pertussis vaccines.

METHODS

To define the immunodominant regions of FHA, four overlapping recombinant fragments were expressed and produced in Escherichia coli and then purified by His-tagged based affinity chromatography. Two groups comprising healthy preschool children (n = 50) and adults (n = 26) were vaccinated with a single dose of commercial whole-cell and acellular DTaP vaccines, respectively. An antigen-based ELISA was applied to measure serum levels of anti-FHA antibody to both native and recombinant proteins in vaccinated volunteers.

RESULTS

In both groups of vaccinated individuals, the anti-FHA antibody response was mainly directed against epitopes located within a fragment of FHA spanning amino acid residues 1877-2250 of the mature FHA molecule (p < 0.001). No or little antibody was detected against the other recombinant segments of FHA.

CONCLUSION

Our results suggest that the human antibody response to FHA is directed to an immunodominant region located within residues 1877-2250 of the FHA molecule. Characterization and epitope mapping of the major components of acellular pertussis vaccine and future modifications in vaccine formulation may improve its efficacy and protectivity.