Role of exosome in autoimmunity, with a particular emphasis on rheumatoid arthritis

Cell-derived exosomes are identified as carriers of lipids, proteins, and genetic materials that participate in cell-cell signal communication, biological process, and cell signaling. Also, their involvement has been reported in a vast array of disorders and inflammatory conditions such as autoimmune diseases. Rheumatoid arthritis (RA), a common cause of joint disorder, is an inflammation-based disease in which the precise understanding of its pathogenesis needs to be further investigated. Also, there is only a palliative care approach for the alleviation of RA symptoms. This paper discusses the recent advances in the biology of exosomes in autoimmune disorders especially in RA, and also provides a new line of research for arthritis therapy using exosomes. © 2020 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Lt

Biochemical and immunological aspects of protein aggregation in neurodegenerative diseases

Protein aggregation is commonly associated with a large number of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and other types of pathological conditions. Misfolding and aggregation of a number of peptides and proteins have been found to occur under these conditions. In the present review, some mechanistic features of the events related to the type of structure-function relationships which may define the outcome of the abnormal conditions are discussed. The immunological responses to the aggregates and possible therapeutic strategies for prevention or control of the diseases are also reviewed. Protein aggregation and its effect on human body have become an important issue over the last two decades. Many diseases in human are related to aggregation and misfolding of different kinds of proteins; therefore, diagnosis of causes of the aggregation and their mechanisms which provoke it are important. This review describes the relations between structures and functions of already aggregated proteins, as well as proteins, which only enter initial stages of aggregation. The consequences of aggregations, which provoke many kinds of neurodegenerative disorders, are explained in details and some factors that may influence their severity are described. In addition, the immunologic responses to these aggregates are discussed. Suggestions of plausible therapies of preventing or slowing down the protein condensation diseases are presented

The Profile of Toll-like Receptor 2 (TLR2), TLR4 and Their Cytosolic Downstream Signaling Pathway in Common Variable Immunodeficiency (CVID) Patients

Common variable immunodeficiency (CVID) is the most common clinical primary antibody deficiency, characterized by increased susceptibility to recurrent bacterial infections. Since Toll-like receptors (TLRs) play an important role in the maturation and differentiation of B-cells, TLRs� defect can be involved in the pathogenesis of CVID. Therefore, we evaluated the expression of TLR2 and TLR4 and their signaling pathway; also their association with autoimmunity, B-cell subtypes and response to pneumovax-23 were assessed in CVID patients. Sixteen CVID patients were enrolled in the study. Flow cytometry was used for assessing the protein expression of TLR2 and TLR4, and real-time PCR was used for gene expression of myeloid differentiation primary response 88 (MyD88) and toll interacting protein (Tollip). We found a higher protein expression of TLR2 in CVID patients which was associated with lower number of end stage B-cells and hyporesponse to pneumovax-23 vaccination. We showed a lower mRNA expression of MyD88 and an almost equal Tollip mRNA expression in CVID patients compared with controls. There was a profound association between MyD88 gene expression and autoimmunity in CVID patients. According to the presence of the lower number of end stage B-cells and poor vaccine response in CVID patients and their correlation with the higher expression of TLR2, we hypothesized that there is a functional defect in this receptor and/or its downstream in the peripheral blood mononuclear cells (PBMCs) of CVID patients. Copyright© April 2018, Iran J Allergy Asthma Immunol. All rights reserved