Mild/moderate hemophilia A patients carrying certain mutations in the C1 domain of factor VIII (FVIII) have a higher risk of inhibitor occurrence. To analyze the mechanisms responsible for inhibitor development in such patients, we characterized FVIII-specific CD4(+) T-cell clones derived from a mild hemophilia A patient carrying an Arg2150His substitution in the C1 domain and who presented with a high titer inhibitor toward normal but not self-FVIII. All T-cell clones recognized synthetic peptides encompassing Arg2150. The peptides were presented to the T-cell clones by DRB1*0401/DRB4*01 or DRB1*1501/DRB5*01. Interestingly, the latter haplotype was previously reported as being associated with an increased incidence of inhibitor formation. Peptide I2144-T2161 also bound to other DR molecules such as DRB1*0101 and DRB1*0701, indicating that the peptide binds to major histocompatibility complex (MHC) class II molecules expressed in more than 60% of the population. None of the T-cell clones recognized recombinant FVIII carrying the substitution Arg2150His, even when FVIII was presented by an FVIII-specific B-cell line. The mutation likely alters T-cell recognition of the mutated peptide associated to MHC molecules, because the mutated peptide bound to immunopurified DR molecules nearly as effectively as the native peptide. These observations demonstrate that T cells of this patient with mutation Arg2150His distinguish between self- and wild-type FVIII and provide a plausible mechanism for the frequent occurrence of an inhibitor in patients carrying this substitution. A similar phenomenon may occur with other mutations associated to an increased incidence of inhibitor formation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1182/blood-2002-05-1369 | DOI Listing |
Cancers (Basel)
December 2024
Department of Cancer Immunotherapy, Fukuoka General Cancer Clinic, Fukuoka 812-0018, Japan.
: Neoantigens have attracted attention as ideal therapeutic targets for anti-tumour immunotherapy because the T cells that respond to neoantigens are not affected by central immune tolerance. Recent findings have revealed that the activation of CD4-positive T cells plays a central role in antitumor immunity, and thus targeting human leukocyte antigen (HLA) class II-restricted neoantigens, which are targets of CD4-positive T cells, is of significance. However, there are very few detailed reports of neoantigen vaccine therapies that use an HLA class II-restricted long peptide.
View Article and Find Full Text PDFFront Immunol
January 2025
Leeds Institute of Medical Research, School of Medicine, University of Leeds, St. James University Hospital, Leeds, United Kingdom.
Background: There has been limited success of cancer immunotherapies in the treatment of ovarian cancer (OvCa) to date, largely due to the immunosuppressive tumour microenvironment (TME). Tumour-associated macrophages (TAMs) are a major component of both the primary tumour and malignant ascites, promoting tumour growth, angiogenesis, metastasis, chemotherapy resistance and immunosuppression. Differential microRNA (miRNA) profiles have been implicated in the plasticity of TAMs.
View Article and Find Full Text PDFCancer Cell
December 2024
Pre-Cancer Immunology Laboratory, University College London Cancer Institute, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6BT, UK; Cancer Research UK Lung Cancer Centre of Excellence. Electronic address:
In this issue of Cancer Cell, Son et al. highlight an unexpected role for skin β-papillomaviruses in the protection against skin carcinogenesis. T cell immunity to skin papillomaviruses blocks the expansion of p53 mutant clones in ultraviolet (UV) radiation-damaged skin, preventing the development of skin cancer.
View Article and Find Full Text PDFPLoS One
January 2025
School of Information and Technology, Wenzhou Business College, Wenzhou, Zhejiang, China.
Liver cancer is the sixth most frequent malignancy and the fourth major cause of deaths worldwide. The current treatments are only effective in early stages of cancer. To overcome the therapeutic challenges and exploration of immunotherapeutic options, broad spectral therapeutic vaccines could have significant impact.
View Article and Find Full Text PDFBr J Haematol
January 2025
Department of Haematology, University College London Hospital, London, UK.
Systemic light chain (AL) amyloidosis is a rare clonal plasma cell disorder characterized by the production of amyloidogenic immunoglobulin light chains, which causes the formation and deposition of amyloid fibrils, leading to multi-organ dysfunction. Current treatment is directed at the underlying plasma cell clone to achieve a profound reduction in the monoclonal free light chain production. The standard-of-care first-line therapy is a combination of daratumumab, cyclophosphamide, bortezomib and dexamethasone (D-VCd regimen), resulting in high rates of haematological and organ responses.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!