Human antiphospholipid antibodies induce TNFα in monocytes via Toll-like receptor 8
The antiphospholipid syndrome (APS) is characterized by recurrent arterial and/or venous thromboses, pregnancy loss and the presence of antiphospholipid antibodies (aPL). One of the discussed mechanisms of this thrombotic activity in APS patients is attributed to TNFalpha secretion in monocytes after aPL stimulation. To investigate this mechanism in detail, we employed a monoclonal aPL and IgG fractions of APS patients for stimulation of human peripheral monocytes. Stimulation with this monoclonal aPL resulted in an increased expression and secretion of TNFalpha, caused by specific upregulation of TLR8 mRNA and protein expression levels. To confirm the specificity of this finding we could d…
A phase I dose-escalation study of IMAB362 (Zolbetuximab) in patients with advanced gastric and gastro-oesophageal junction cancer
Introduction IMAB362 (Zolbetuximab) is a chimeric monoclonal antibody that binds to Claudin-18.2, a target antigen specific to cancer cells. In vitro, IMAB362 mediates cell death through antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity; thus, IMAB362 may serve as a potent, targeted immunotherapeutic agent. Methods This first-in-human phase I study enroled adult patients (N = 15) with advanced gastric or gastro-oesophageal junction cancer into five sequential single dose-escalation cohorts (33, 100, 300, 600, and 1000 mg/m2) following a 3 + 3 design. Safety/tolerability, including determination of maximum tolerated dose and recommended phase II dose, were the pr…
TLR7 and TLR8 ligands and antiphospholipid antibodies show synergistic effects on the induction of IL-1beta and caspase-1 in monocytes and dendritic cells.
TLRs represent the first line of defense against invading pathogens in the innate immune system. Certain cytokines are important mediators and essentially necessary to assure an appropriately regulated immune response. Recent data gave initial evidence that IL-1beta is one of the most relevant members of these regulating cytokines. We investigated the induction of IL-1beta production in monocytes and pDCs stimulated with ligands for TLR7 and TLR8 and with antiphospholipid antibodies (aPL). Using human monocytes and pDCs for stimulation with specific TLR7 and TLR8 ligands such as resiquimod (R848) and single stranded RNA (RNA42) as well as with a human monoclonal aPL HL5B resulted in a speci…
Nucleic acid recognizing Toll-like receptors and autoimmunity
The understanding of autoimmune diseases experienced an impressive boost since the Toll-like receptors (TLRs) have been identified as possible key players in autoimmune pathophysiology. Although these receptors recognize a variety of structures derived from viruses, bacteria, and fungi leading to subsequent initiation of the relevant immune responses, recent data support the idea that TLRs are crucial in the induction and perpetuation of certain autoimmune diseases, especially the systemic lupus erythematosus (SLE). In this review, we will summarize recent data on involvement of TLRs in the development of autoimmune diseases. We will focus on TLRs 7, 8, and 9 that were originally identified…
Clr-a: A Novel Immune-Related C-Type Lectin-like Molecule Exclusively Expressed by Mouse Gut Epithelium
Abstract The mouse gut epithelium represents a constitutively challenged environment keeping intestinal commensal microbiota at bay and defending against invading enteric pathogens. The complex immunoregulatory network of the epithelial barrier surveillance also involves NK gene complex (NKC)–encoded C-type lectin-like molecules such as NKG2D and Nkrp1 receptors. To our knowledge, in this study, we report the first characterization of the orphan C-type lectin-like molecule Clr-a encoded by the Clec2e gene in the mouse NKC. Screening of a panel of mouse tissues revealed that Clec2e transcripts are restricted to the gastrointestinal tract. Using Clr-a–specific mAb, we characterize Clr-a as a …