Inhibition of phosphatidylserine recognition heightens the immunogenicity of irradiated lymphoma cells in vivo.

Strategies to enhance the immunogenicity of tumors are urgently needed. Although vaccination with irradiated dying lymphoma cells recruits a tumor-specific immune response, its efficiency as immunogen is poor. Annexin V (AxV) binds with high affinity to phosphatidylserine on the surface of apoptotic and necrotic cells and thereby impairs their uptake by macrophages. Here, we report that AxV preferentially targets irradiated lymphoma cells to CD8+ dendritic cells for in vivo clearance, elicits the release of proinflammatory cytokines and dramatically enhances the protection elicited against the tumor. The response was endowed with both memory, because protected animals rejected living lymphoma cells after 72 d, and specificity, because vaccinated animals failed to reject unrelated neoplasms. Finally, AxV-coupled irradiated cells induced the regression of growing tumors. These data indicate that endogenous adjuvants that bind to dying tumor cells can be exploited to target tumors for immune rejection.

Polymorphisms in the Hsp70 gene locus are genetically associated with systemic lupus erythematosus.

BACKGROUND: Heat shock proteins (Hsps) play a role in the delivery and presentation of antigenic peptides and are thought to be involved in the pathogenesis of multifactorial diseases. OBJECTIVE: To investigate genes encoding cytosolic Hsp70 proteins for associations of allelic variants with systemic lupus erythematosus (SLE). METHODS: Case-control studies of two independent Caucasian SLE cohorts were performed. In a haplotype-tagging single-nucleotide polymorphism approach, common variants of HspA1L, HspA1A and HspA1B were genotyped and principal component analyses were performed for the cohort from the Oklahoma Medical Research Foundation (OMRF). Relative quantification of mRNA was carried out for each Hsp70 gene in healthy controls. Conditional regression analysis was performed to determine if allelic variants in Hsp70 act independently of HLA-DR3. RESULTS: On analysis of common genetic variants of HspA1L, HspA1A and HspA1B, a haplotype significantly associated with SLE in the Erlangen-SLE cohort was identified, which was confirmed in the OMRF cohort. Depending on the cohorts, OR ranging from 1.43 to 1.88 and 2.64 to 3.16 was observed for individuals heterozygous and homozygous for the associated haplotype, respectively. Patients carrying the risk haplotype or the risk allele more often displayed autoantibodies to Ro and La in both cohorts. In healthy controls bearing this haplotype, the amount of HspA1A mRNA was significantly increased, whereas total Hsp70 protein concentration was not altered. CONCLUSIONS: Allelic variants of the Hsp70 genes are significantly associated with SLE in Caucasians, independently of HLA-DR3, and correlate with the presence of autoantibodies to Ro and La. Hence, the Hsp70 gene locus appears to be involved in SLE pathogenesis.

Rheumatology Common Toxicity Criteria (RCTC): An Update Reflecting Real-World Use.

INTRODUCTION: The Outcome Measures in Rheumatology Clinical Trials (OMERACT) Rheumatology Common Toxicity Criteria (RCTC) version 2.0 was published in 2007 by the OMERACT Drug Safety Working Group, building on limited experience with RCTC version 1.0, to facilitate standardization of assessment (grading) and reporting of adverse events (AEs) commonly seen in rheumatic disease clinical trials (Woodworth et al. in J Rheumatol 34:1401-1414, 2007). OBJECTIVES: The objectives of this study were to (1) report the real-world performance of RCTC 2.0; (2) report immediately correctable errors in RCTC 2.0, and provide a revised RCTC 2.1; and (3) begin to identify the need for a comprehensive revision of RCTC 2.0. METHODS: Safety data outputs for several large rheumatic/autoimmune disease clinical trials in which RCTC 2.0 was used were evaluated for accuracy of reporting and the ability to assess differences among treatments. We examined RCTC 2.0 tables for errors, as well as for omission of terms for AEs that commonly occur in more recent rheumatology clinical trials. We also considered recommendations from recent US Food and Drug Administration (FDA) and international initiatives such CDISC (Clinical Data Interchange Standards Consortium) to improve the consistency of safety data collection and interpretability of safety data analyses. RESULTS: RCTC 2.0 enabled comparisons of safety data across treatment groups, including grading. However, we discovered inaccuracies in laboratory results grading and omission of AE terms now recognized to occur in rheumatic disease clinical trials. CONCLUSION: The RCTC 2.0 performed as intended, although some inaccuracies and omissions were found. We provide a corrected version, RCTC 2.1, and also recommend further revision of the RCTC within OMERACT guidances to include AEs that have been reported in rheumatology clinical trials since RCTC 2.0 was published. Ideally, a revised RCTC 3.0 would not only facilitate standardized assessment and reporting of AEs, but would also expand and encourage accurate comparison of the safety profiles of treatments for rheumatic/autoimmune diseases.

Exposure of anionic phospholipids serves as anti-inflammatory and immunosuppressive signal--implications for antiphospholipid syndrome and systemic lupus erythematosus.

In contrast to necrotic cells, the clearance of apoptotic ones usually is an anti-inflammatory process which elicits only a marginal immune response. During apoptosis phosphatidylserine (PS) is exposed on the outer leaflet of the cytoplasmic membrane and serves as target for the PS receptor of phagocytes. The latter is responsible for anti-inflammatory signalling and the induction of TGFbeta. We were interested whether the immunogenicity of apoptotic cells can be increased by masking PS. We observed that treatment of xenogeneic apoptotic cells with annexin V (AxV) significantly increased the humoral immune response against surface epitopes of these cells. Furthermore, AxV-coated irradiated tumour cells were able to elicit a long lasting tumour specific cytotoxic T lymphocyte response. AxV efficiently blocked the uptake of irradiated cells by macrophages but not by dendritic cells. Furthermore, AxV skewed the phagocytosis of irradiated cells towards inflammation. Investigation of patients with autoimmune diseases further supported the role of anionic surface phospholipids for anti-inflammatory clearance of apoptotic cells. Impaired clearance and opsonisation with anti-phospholipid-antibodies are discussed to be responsible for the development of systemic lupus erythematosus and anti-phospholipid-syndrome, respectively. Presentation of cryptic epitopes from late apoptotic cells in a proinflammatory context may challenge T cell tolerance. In addition, accumulation of uncleared apoptotic debris in the germinal centres of lymph nodes may result in the survival of autoreactive B cells.

Periarticular bone structure in rheumatoid arthritis patients and healthy individuals assessed by high-resolution computed tomography.

OBJECTIVE: To define the nature of structural bone changes in patients with rheumatoid arthritis (RA) compared with those in healthy individuals by using the novel technique of high-resolution microfocal computed tomography (micro-CT). METHODS: Fifty-eight RA patients and 30 healthy individuals underwent a micro-CT scan of the proximal wrist and metacarpophalangeal joints. Bone lesions such as cortical breaks, osteophytes, and surface changes were quantified on 2-dimensional (2-D) slices as well as by using 3-D reconstruction images, and exact localization of lesions was recorded. RESULTS: Micro-CT scans could detect bone lesions <0.5 mm in width or depth. Small erosions could be observed in healthy individuals and RA patients, whereas lesions >1.9 mm in diameter were highly specific for RA. Cortical breaks were mostly found along the radial sites of the metacarpal heads. No significant difference in the presence of osteophytes between healthy individuals and RA patients was found. Cortical surface changes, presumably cortical thinning and fenestration, became evident from 3-D reconstructions and were more pronounced in RA patients. CONCLUSION: Micro-CT allows exact detection of morphologic changes of juxtaarticular bone in healthy individuals and RA patients. Even healthy individuals occasionally show bone changes, but the severity of these lesions, with the exception of osteophytes, is greater in RA patients. Thus, micro-CT allows accurate differentiation among physiologic bone changes in joints and among types of pathologic bone damage resulting from RA.