Exosomes (EXO) derived from tumour cells have been used to stimulate antitumour immune responses, but only resulting in prophylatic immunity. Tumour-derived heat shock protein 70 (HSP70) molecules are molecular chaperones with a broad repertoire of tumour antigen peptides capable of stimulating dendritic cell (DC) maturation and T-cell immune responses. To enhance EXO-based antitumour immunity, we generated an engineered myeloma cell line J558HSP expressing endogenous P1A tumour antigen and transgenic form of membrane-bound HSP70 and heat-shocked J558HS expressing cytoplasmic HSP70, and purified EXOHSP and EXOHS from J558HSP and J558HS tumour cell culture supernatants by ultracentrifugation. We found that EXOHSP were able to more efficiently stimulate maturation of DCs with up-regulation of Iab, CD40, CD80 and inflammatory cytokines than EXOHS after overnight incubation of immature bone-marrow-derived DCs (5 × 106 cells) with EXO (100 μg), respectively. We also i.v. immunized BALB/c mice with EXO (30 μg/mouse) and assessed P1A-specific T-cell responses after immunization. We demonstrate that EXOHSP are able to stimulate type 1 CD4+ helper T (Th1) cell responses, and more efficient P1A-specific CD8+ cytotoxic T lymphocyte (CTL) responses and antitumour immunity than EXOHS. In addition, we further elucidate that EXOHSP-stimulated antitumour immunity is mediated by both P1A-specific CD8+ CTL and non-P1A-specific natural killer (NK) responses. Therefore, membrane-bound HSP70-expressing tumour cell-released EXO may represent a more effective EXO-based vaccine in induction of antitumour immunity.

Active T cells release bioactive exosomes (EXOs). However, its potential modulation in immune responses is elusive. In this study, we in vitro generated active OVA-specific CD8+ T cells by cultivation of OVA-pulsed dendritic cells (DCOVA) with naive CD8+ T cells derived from OVA-specific TCR transgenic OTI mice and purified EXOs from CD8+ T cell culture supernatant by differential ultracentrifugation. We then investigated the suppressive effect of T cell EXOs on DCOVA-mediated CD8+ CTL responses and antitumor immunity. We found that DCOVA uptake OTI T cell EXOs expressing OVA-specific TCRs and Fas ligand via peptide/MHC Ag I–TCR and CD54–LFA-1 interactions leading to downregulation of peptide/MHC Ag I expression and induction of apoptosis of DCOVA via Fas/Fas ligand pathway. We demonstrated that OVA-specific OTI T cell EXOs, but not lymphocytic choriomeningitis virus-specific TCR transgenic mouse CD8+ T cell EXOs, can inhibit DCOVA-stimulated CD8+ CTL responses and antitumor immunity against OVA-expressing B16 melanoma. In addition, these T cell EXOs can also inhibit DCOVA-mediated CD8+ CTL-induced diabetes in transgenic rat insulin promoter-mOVA mice. Interestingly, the anti–LFA-1 Ab treatment significantly reduces T cell EXO-induced inhibition of CD8+ CTL responses in both antitumor immunity and autoimmunity. EXOs released from T cell hybridoma RF3370 cells expressing OTI CD8+ TCRs have a similar inhibitory effect as T cell EXOs in DCOVA-stimulated CTL responses and antitumor immunity. Therefore, our data indicate that Ag-specific CD8+ T cells can modulate immune responses via T cell-released EXOs, and T cell EXOs may be useful for treatment of autoimmune diseases.

Scr-based equations did not appear to be inferior to Cys C-based equations as a means to estimate GFR in renal transplant patients.

Protein electrophoresis is commonly used as an aid in the diagnosis of monoclonal gammopathies and is performed in many laboratories in Canada and throughout the world. However, unlike many other diagnostic tests, there is limited guidance for standardization and neither guidance nor specific recommendations for clinical reporting of serum (SPE) or urine (UPE) protein electrophoresis and immunotyping available in the literature. Therefore, a Canadian effort was undertaken to recommend standards that cover all aspects of clinical reporting with an ultimate goal towards reporting standardization. The Canadian Society of Clinical Chemists (CSCC) Monoclonal Gammopathy Interest Group (MGIG), which is composed of CSCC members with an interest in protein electrophoresis, has formed a Monoclonal Gammopathy Working Group (MGWG) to take initial steps towards standardization of SPE, UPE and immunotyping. Candidate standardization recommendations were developed, discussed and voted upon by the MGWG. Candidate recommendations that achieved 90% agreement are presented as consensus recommendations. Recommendations that did not achieve 90% consensus remain candidate recommendations and are presented with accompanying MGWG discussion. Eleven consensus recommendations along with candidate recommendations for nomenclature, protein fraction reporting, test utilization, interference handling and interpretive reporting options are presented.