In silico perspectives on the prediction of the PLP's epitopes involved in multiple sclerosis

Background: Multiple sclerosis [MS] is the most common autoimmune disease of the central nervous system [CNS]. The main cause of the MS is yet to be revealed, but the most probable theory is based on the molecular mimicry that concludes some infections in the activation of T cells against brain auto-antigens that initiate the disease cascade

Objectives: The Purpose of this research is the prediction of the auto-antigen potency of the myelin proteolipid protein [PLP] in multiple sclerosis

Materials and Methods: As there wasn't any tertiary structure of PLP available in the Protein Data Bank [PDB] and in order to characterize the structural properties of the protein, we modeled this protein using prediction servers. Meta prediction method, as a new perspective in silico, was performed to find PLPs epitopes. For this purpose, several T cell epitope prediction web servers were used to predict PLPs epitopes against Human Leukocyte Antigens [HLA]. The overlap regions, as were predicted by most web servers were selected as immunogenic epitopes and were subjected to the BLASTP against microorganisms

Results: Three common regions, AA[58-74], AA[161-177], and AA[238-254] were detected as immunodominant regions through meta-prediction. Investigating peptides with more than 50% similarity to that of candidate epitope AA[58-74] in bacteria showed a similar peptide in bacteria [mainly consistent with that of clostridium and mycobacterium] and spike protein of Alphacoronavirus 1, Canine coronavirus, and Feline coronavirus. These results suggest that cross reaction of the immune system to PLP may have originated from a bacteria or viral infection, and therefore molecular mimicry might have an important role in the progression of MS

Conclusions: Through reliable and accurate prediction of the consensus epitopes, it is not necessary to synthesize all PLP fragments and examine their immunogenicity experimentally [in vitro]. In this study, the best encephalitogenic antigens were predicted based on bioinformatics tools that may provide reliable results for researches in a shorter time and at a lower cost

Analysis of 5HT3Ra gene expression by real time PCR in systemic lupus erythematosus [SLE] patients

Systemic lupus erythemathosus is an autoimmune disease that affected many various types of tissues in 10% of world population and over 30 genes has associated with it. Nouroimmunoendocrynology concepts have shown that immune system could be affected by neuron system and vice versa, 5-hydroxytryptamine receptor a [5HT3Ra] was studied as a main receptor in these relations. In this study, peripheral blood sample were collected from [SLE] patient and normal individuals. The total cellular RNAs were extracted and the cDNAs were synthesized. This process was followed by real-time PCR using specific primers for 5HT3Ra gene and beta-actin gene as internal control. Eventually PCR products have been sequenced. Results of this study suggested that this special receptor expressed in polymorpho-nuclear cells. We found over expression of 5HT3Ra in patients in comparison with healthy individuals group. Interestingly, some nucleotide changes have been found in 5HT3Ra gene in patients but not found sequential nucleotide changes in healthy individuals group. This study supposed that over expression of 5HT3Ra gene in SLE patients lead to over activation of immune cells that derived from over stimulation of them from serotonin blood serum that finally lead to autoimmune reactions that terminated in SLE

[Bacterial overexpression of the human interleukin-2 in insoluble form via the pET Trx fusion system]

Selection of a system for successful recombinant protein production is important. The aim of this study was to produce high levels of human interleukin-2 [hIL-2] in soluble form. To this end, the pET32a vector in Escherichia coli BL21 [DE3] was used as an expression system, since it was previously used for the production of mouse IL-2 in soluble form. The results indicated that contrary to expectations, the expressed protein was in the form of inclusion bodies and perhaps amino acid differences between human and mouse IL-2 should be determinant. The hIL-2 protein is a small peptide, therefore its recovery as a biologically functional protein by the process of refolding may be feasible and could lead to high yields at the industrial scale

detection of dopamine gene receptors [DRD[1]-DRD[5]] expression on human peripheral blood lymphocytes by real time PCR

There is interrelationship between the immune and nervous systems that is accomplished by the molecular mediators. Dopamine is one of the most important neurotransmitters. Five different dopamine receptor genes [DRD1, DRD2, DRD3, DRD4, and DRD5] have been recognized and cloned. The expression of the dopamine receptors is well characterized in the brain but little work has been done to examine their expression in other organ tissues. In certain diseases of the immune and nervous systems, alterations in dopamine receptors gene expression in different cells have been reported. This suggests that dopamine and its receptors have important role in pathophysiology of above-mentioned diseases. In the present study, using Real Time Polymerase Chain Reaction [PCR] technique, we investigated dopamine receptors genes expression in PBMC of normal individuals. The PBMC was separated from normal whole blood by Ficoll-hypaque; the total cellular RNA was then extracted and the cDNA was synthesized. This process followed by real time-PCR using primer pairs specific for five dopamine receptors mRNAs and beta-actin as internal control. The results showed the presence of all types of dopamine receptors in lymphocytes of normal individuals. The specificities of the obtained PCR products for the respective dopamine receptors fragments were confirmed by sequenced analysis capillary system. In conclusion, the present study has shown that human lymphocytes express five dopamine receptors DR1-DR5. However, the conclusive evidence on the possible function of these receptors in lymphocytes remains unknown. Because lymphocytes express all of the five neuronal dopamine receptors, it is quite reasonable to consider them as a model of dopaminergic neuron