Non-invasive in vivo imaging of brain and retinal microglia in neurodegenerative diseases.

Microglia play crucial roles in immune responses and contribute to fundamental biological processes within the central nervous system (CNS). In neurodegenerative diseases, microglia undergo functional changes and can have both protective and pathogenic roles. Microglia in the retina, as an extension of the CNS, have also been shown to be affected in many neurological diseases. While our understanding of how microglia contribute to pathological conditions is incomplete, non-invasive in vivo imaging of brain and retinal microglia in living subjects could provide valuable insights into their role in the neurodegenerative diseases and open new avenues for diagnostic biomarkers. This mini-review provides an overview of the current brain and retinal imaging tools for studying microglia in vivo. We focus on microglia targets, the advantages and limitations of in vivo microglia imaging approaches, and applications for evaluating the pathogenesis of neurological conditions, such as Alzheimer's disease and multiple sclerosis.

The immunomodulatory effects of the C-type lectin protein of Toxocara canis on experimental autoimmune encephalomyelitis.

Toxocara canis is a global zoonosis infection that can cause chronic and long-term toxocariasis in their paratenic host. The excretory-secretory (ES) products of T. canis larvae are considered to be responsible for the Th2 polarization and regulatory immune responses in toxocariasis. The C-type lectin family is one of the most prominent components of ES products of T. canis infective larvae. This study aimed to investigate the ameliorative effect of a T. canis C-type lectin recombinant protein (rCTL), on experimental autoimmune encephalomyelitis (EAE) which is a T-cell-mediated autoimmune disease of the central nervous system. C57BL/6 mice were subcutaneously treated with 30 µg rCTL, three times at an interval of 1 week. EAE was induced by myelin oligodendrocyte glycoprotein 35-55 peptide (MOG35-55 peptide) immunization, and weight and clinical scores were evaluated. Real time polymerase chain reaction was performed to evaluate the expression levels of T-bet, Gata3, and Foxp3 in splenocytes. In addition, the levels of interleukin 4, interferon gamma, and tumour growth factor-ß (TGF-ß) were quantified by enzyme-linked immunosorbent assay in splenocyte culture supernatants. The results indicated that the rCTL decreased clinical disability scores and delayed the onset of EAE. Furthermore, the data showed that rCTL treatment modulated the immune response, which was associated with upregulation of the mRNA expression of the Foxp3 gene and higher production of TGF-ß in rCTL-treated mice. This study demonstrated that rCTL might be a potential agent to ameliorate EAE symptoms by stimulating anti-inflammatory responses.

Phylogenetic Analysis of C Type Lectin from Toxocara canis Infective Larvae and Comparison with the C Type Lectin Family in the Immune System of Mouse and Human.

BACKGROUND: C type lectin (CTL) family is a type of calcium-dependent proteins found in vertebrates and invertebrates. The objective of this study was to perform a comparative analysis and phylogenetic inferring for understanding the similarities and differences of carbohydrate recognition domain (CRD) domain of Toxocara canis CTL and other nematodes, and similar C type lectin involved in the immune system of mouse and human as their host. METHODS: The female T. canis was retrieved from the 2-6 months puppies (Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, 2015). To collect T. canis eggs, the worms were cultured for 5 d until they were embryonated. The hatching process was accelerated for collecting the stage 2 larvae, and the larvae were cultured for a week. A cDNA library was made from the total mRNA of T. canis infective larvae. The PCR amplification for C type lectin gene was performed and the amino acids were analyzed using the alignment method and the construction of phylogenetic tree. RESULTS: The suspension sample maintained at 30 ºC for four weeks could embryonate 90%-100% of eggs. T. canis CTL gene was 657 bp in length and encoded a protein with 219 amino acids. The CTL of species of Strongylida order were closely placed in the tree, whereas the members of Ascaridida orders were located in a separate branch. High levels of similarity (36%-44%) and conservation of C type lectin from T. canis with mouse and human C type lectins. Its C type lectin showed a higher similarity with asialoglycoprotein receptor (ASGPR), macrophage lectin, dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN), MINCLE receptor of mouse and human. CONCLUSION: Analysis of CRD domain of C type lectin protein could make a better understanding of their role in the interaction of nematode parasite with their hosts.

Evaluation of Dot Immunogold Filtration Assay (DIGFA) By Recombinant Protein EPC1 for Anti- Echinococcus granulosus IgG Antibody.

BACKGROUND: Cystic echinococcosis is an important zoonosis caused by the Echinococcus granulosus with a substantial impact in human and animal health in endemic areas. The purpose of the present study was serodiagnosis optimizing of dog echinococcosis in order to achieve a rapid diagnostic method. METHODS: Eight dogs were challenged with protoscoleces in order to have positive echinococcosis serum and 2 two-month old puppies were used as uninfected controls. Colloidal gold was prepared by controlled reduction of a boiling solution of chloroauric acid (H [AuCl4]) with sodium citrate and labeled with recombinant EPC1. Dot immunogold filtration assay (DIGFA) was developed by coating rEPC1 labeled colloidal gold on nitrocellulose membrane. The canine sera, taken three times including, 15, 28 and 35 days post infection were tested. A total of 30 serum samples including 24 sera from 8 infected dogs and 6 sera from 2 puppies were comparatively detected with both DIGFA and ELISA. RESULTS: Gold labeled antigen, showed a dark purple dot with agglutination particles in positive sera and light purple dot without agglutination in negative sera. Among 30 serum samples, 23 were positive and 7 were negative with DIGFA and 24 were positive, 6 were negative with ELISA. CONCLUSION: DIGFA as a rapid and simple procedure could be utilized in quickly diagnosis of echinococcosis.

Immunoproteomics approach for EPC1 antigenic epitope prediction of G1 and G6 strains of Echinococcus granulosus.

It is important to establish the diagnosis of cystic echinococcosis (CE) infection and begin control management. Currently, it is difficult to make an accurate diagnosis of CE without the availability of an accurate test, which requires the use of sensitive and specific antigens. Using recombinant antigens the sensitivity and specificity of the CE serology assays could be improved considerably. Recently, a highly antigenic protein named EPC1was characterized and isolated from an Echinococcus granulosus protoscoleces. The current study was designed to assess the sequences of EPC1 isolated from different intermediate hosts of E. granulosus. In addition, identification of a highly antigenic linear B cell epitope was found within EPC1 antigen candidate. The EPC1 sequence contains coding and non-coding regions and was compared between two predominant strains (G1 and G6) in Iran. Sequence polymorphism was not found in protein coding regions, suggesting that these regions may be useful for identification of protein expression as an antigen. The average antigenic activity for the whole protein is above 1.1, and hydrophobicity below 0 indicates that it is hydrophilic. Structural analysis showed alpha helical regions in amino acids 6-25, 35-44, 52-62, and 72-78. Nine B cell epitope residues were identified out of 67 total residues. The identity of EPC1 sequence in both G1 and G6 genotypes affects the antigenic efficacy of EPC1and suggests the recombinant protein will be useful in serological assays in the regions where the two strains are prevalent.