Iranian Biomedical Journal
Volume:16 Issue: 3, Jul 2012

Targeting of CD20 antigen with monoclonal antibodies has become the mainstay in the treatment of non-Hodgkin''s lymphomas and immunotherapeutic depletion of malignant B cells. Accessibility of antigen is one of the crucial factors in development of monoclonal antibodies against this antigen. One major problem in expression of full length CD20 is aggregation and misfolding. Therefore, production of a polypeptide is easer and favorable comparing to that of a full length transmembrane protein CD20. In this study, we expressed the extra membrane loop of hCD20 (exCD20) consisting of a non-glycosylated 47-amino acids region. The exCD20 coding sequence was amplified by PCR and cloned in pET32a(+) expression vector. The desired protein was expressed in fusion with thioredoxin and 6× His tag in E. coli Origami strain. ELISA and Western-blotting data were performed to indicate the functionality of this protein. We have obtained the exCD20 recombinant protein which can be detected in ELISA and Western-blot experiments. This recombinant fusion protein was soluble and stable without aggregation and misfolding problems. The recombinant extra membrane loop of human CD20 protein in fusion with thioredoxin (exCD20) can be used in function assays and some applications such as ELISA, immuneblotting, affinity purification, immunization, screening, and development of anti-CD20 antibodies.

Gap junctions composed of connexins (Cx) are functional in cell defense by propagation of toxic/death molecules to neighboring cells. Hippocampus, one of the brain regions with particular vulnerability to damage, has a wide network of gap junctions. Functional response of astrocytic Cx30 and neuronal Cx32 to hippocampal damage is unknown. We infused lipopolysaccharide (LPS) intracerebroventricularly (2.5 µg/rat) once daily for two weeks to create neuroinflammation. The mRNA and protein levels of the Cx were measured in the hippocampus after 1st, 7th and 14th injection by real-time PCR and Western-blot techniques. A significant increase in Cx32 and Cx30 gene expression was observed after 7th and 14th injection of LPS with no significant change in their protein abundance. Transcriptional overexpression of hippocampal Cx30 and Cx32 could be an adaptive response to production of intracellular toxic molecules but it is not accompanied with post- transcriptional overexpression and might have no functional impact.

Infection with Escherichia coli O157:H7 rarely leads to bloody diarrhea and causes hemolytic uremic syndrome with renal failure that can be deadly dangerous. Intimin, translocated Intimin receptor (Tir), and enterohemorrhagic E. coli (EHEC) secreted protein A (EspA) proteins are the virulence factors expressed by locus of enterocyte effacement locus of EHEC. This bacterium needs EspA as a conduit for Tir delivery into the host cell and the surface arrayed Intimin, which docks the bacterium to the translocated Tir. Here we used triplet synthetic gene (eit) which was designed from three genes: espA coding EspA 120 lacking 36 amino acids from the N-terminal of the protein, eae coding Intimin constructed of 282 amino acids from the C-terminal and tir coding Tir 103, residues 258-361 which interacts with Intimin. The multimeric gene was cloned in two eukaryotic vectors pAAV-multiple cloning site-green fluorescent protein and pCI-neo. The pAAV was used for gene expression assay in cell line 293T and pCI-neo-EIT (EspA, Intimin, Tir) was used as DNA vaccine in mice. Test groups were injected intramuscularly with pCI-neo-EIT four times and mice control group was injected under the same conditions with PBS or pCI-neo vector. The titration of serums showed that BALB/c mice were successfully immunized with DNA vaccine compared to control groups and also they were protected against challenges of live oral using E. coli O157:H7. The results suggest that the DNA vaccine could induce protective immunity either alone or in combination with purified antigens to reduce EHEC infection.

Salivary gland tumors (SGT) are rare lesions with uncertain histopathology. One of the major signaling pathways that participate in the development of several tumors is protein kinase A. In this pathway, glycogen synthase kinase β (GSK3β) and cAMP responsive element binding protein (CREB3) are two genes which are supposed to be down regulated in most human tumors. The expression level of the genes was evaluated in SGT to scrutinize their possible under expression in these tumors.

Forty eight fresh tissue samples were obtained from patients with benign and malignant SGT, including pleomorphic adenoma, warthin’s tumor, mucoepidermoid carcinoma (MEC), salivary duct carcinoma and carcinoma ex pleomorphic adenoma. Eight normal samples were used as controls. Quantitative real-time PCR was used to analyze the expression level of interest genes.

Data was analyzed by statistical methods. GSK3β was downregulate in all samples and all results were statistically significant (P<0.05). CREB3 did not show a significant decrease or increase in its mRNA expression, but the results were significant in MEC and salivary duct carcinoma.

GSK3β down regulation has been reported in many human tumors. This gene stimulates CREB3, inducing cell proliferation and oncogenesis. Our findings showed GSK3β down regulation; however, CREB3 expression level was close to normal group. No association between CREB3 expression and inactivated GSK3β could be postulated in SGT.

Testosterone and its metabolites have important roles in learning and memory. The current study has conducted to assess the effect of pre-training, post-training and pre-probe trial intrahippocampal CA1 administration of 3α-anderostanediol (one of the metabolites of testosterone) and indomethacin (as 3α-hydroxysteroid dehydrogenase enzyme blocker) on acquisition, consolidation and retrieval in Morris water maze (MWM) task.

Adult male rats were bilaterally cannulated into CA1 region of hippocampus and then received 3α-diol (0.2, 1, 3 and 6 μg/0.5 μl/side), indomethacin (1.5, 3 and 6 μg/0.5 μl/side), indomethacin (3 μg/0.5 μl/side) + 3α-diol (1 μg/0.5 μl/side), 25-35 min before training, immediately after training and 25-35 min before probe trial in MWM task.

Our results showed that injection of 3α-diol and indomethacin significantly increased the escape latency and traveled distance to find hidden platform in acquisition and consolidation stage, but did not have any effect on retrieval of spatial learning as compared with the control group.

It is concluded that intra-CA1 administration of 3α-diol and indomethacin could impair spatial learning and memory in acquisition and consolidation stage. Also, intrahippocampal injection of indomethacin + 3α-diol could not change spatial learning and memory impairment effect of indomethacin or 3α-diol in MWM task.

Galantamine is a drug used for the treatment of Alzheimer’s disease and some other cognitive disorders. It is an inhibitor of acetylcholinesterase; however, interaction with nicotinic acetylcholine receptors has also been reported. Owing to the significant role of cholinergic anti-inflammatory pathways in neuro-immunomodulation, we decided to examine the effect of galantamine on tularemia-infected BALB/c mice. Animals were infected with Francisella tularensis LVS and treated with galantamine (0.1 mg/kg of body weight). Total mortality over the course of tularemia infection was assessed and interleukin 6 (IL-6) and interferon gamma (IFN-) in plasma samples were measured by enzyme-linked immunosorbent assays. Apart from the cytokine assays, biochemical markers such as inorganic phosphate, uric acid, lactate dehydrogenase, gamma glutamyltransferase, creatinine phosphokinase and amylase were assayed. The modulation of immunity by galantamine depended on two opposing processes: up-regulation of IFN- and down-regulation of IL-6. Tularemia infection resulted in significant nephropathy, as hyperphosphataemia and hyperuricaemia occurred in infected animals. In addition, galantamine resulted in the mitigation of nephropathy, and markers of kidney dysfunction were modulated. Alterations in mortality were also found in this study. Galantamine can significantly influence the immune response via the cholinergic anti-inflammatory pathway. Despite the decrease in IL-6 levels, galantamine treatment enhanced protection against the intracellular pathogen F. tularensis, resulting in the remission of some pathology and reduced mortality.

Fatty acids are known to be critically important in multiple biological functions. Phospholipid fatty acids of follicular fluid, an important microenvironment for the development of oocytes, may contribute to the women’s fertility and the efficacy of assisted reproduction techniques. The aim of this study was to investigate the effect of fatty acid composition of follicular fluid phospholipids on women undergoing assisted reproductive techniques. Follicular fluid samples were obtained from 100 patients, referred to Tabriz Alzahra Hospital. Seventy-nine subjects underwent in vitro fertilization (IVF) and the remaining 21 underwent intracytoplasmic sperm injection (ICSI). Total lipid of follicular fluid was extracted and fatty acids were analyzed by gas-liquid chromatography. Saturated fatty acids (SFA, P = 0.002) and the ratio of SFA to polyunsaturated fatty acids (P = 0.001) were correlated negatively with a number of mature oocytes after age adjustment. Linoleic acid (P = 0.006) was positively correlated, while the level of arachidonic acid was negatively correlated with fertility percentage after adjustment for body mass index, sperm count, sperm motility. Since phospholipids are one of the major components of lipid metabolism, the results of this study highlight the importance of this component in follicular fluid lipid metabolism. Consequently, it is proposed as an index in determination of the rate of success in assisted reproductive techniques such as IVF/ICSI.

Mucopolysaccharidosis type-VI (MPS-VI), which is inherited as an autosomal recessive trait, results from the deficiency of N-acetylgalactosamine 4-sulfatase (arylsulfatase B) activity and the lysosomal accumulation of dermatan sulfate. In this study, ARSB mutation analysis was performed on three unrelated patients who were originally from the West Azerbaijan province of Iran.

After PCR and direct DNA sequencing, DNA extraction was performed.

Sequencing analysis revealed a novel homozygous missense mutation in the ARSB gene at c.1457A>G [p. D486V] in three unrelated Iranian MPS-VI patients with different phenotype severity.

The mutation type in three patients was the same; probably, because of a foundation effect on their population.