Soluble HLA-G molecules increase during acute leukemia, especially in subtypes affecting monocytic and lymphoid lineages.

Human leukocyte antigen G (HLA-G) molecules exhibit immunomodulatory properties corresponding to nonclassic class I genes of the major histocompatibility complex. They are either membrane-bound or solubly expressed during certain tumoral malignancies. Soluble human leukocyte antigen G (sHLA-G) molecules seem more frequently expressed than membrane-bound isoforms during hematologic malignancies, such as lymphoproliferative disorders.

Total soluble HLA class I and soluble HLA-G in multiple myeloma and monoclonal gammopathy of undetermined significance.

Serum beta2-microglobulin, the light chain of the HLA class I molecular complex, remains one of the best survival prognostic factors in multiple myeloma, but other HLA class I molecules might be of interest in monoclonal gammopathies. In this study, we evaluate total soluble HLA class I (HLA-Is) and soluble HLA-G (HLA-Gs) in 103 patients with newly diagnosed multiple myeloma, 30 patients with monoclonal gammopathy of undetermined significance (MGUS), and 30 healthy subjects, studying their prognostic value in multiple myeloma. In multiple myeloma patients, HLA-Is and HLA-Gs median values were 0.

MHC class II signaling function is regulated during maturation of plasmacytoid dendritic cells.

Dendritic cells (DC) play a central role in the immune response, linking innate and adaptative responses to pathogens. Myeloid DC (MDC) produce interleukin-12 in response to bacterial stimuli, whereas plasmacytoid DC (PDC) produce high levels of type I interferon upon viral infection. Human leukocyte antigen (HLA)-DR engagement has been shown to induce apoptosis in various antigen-presenting cells (APC).

Loss of heterozygosity, a frequent but a non-exclusive mechanism responsible for HLA dysregulation in non-Hodgkin's lymphomas.

The frequent alteration of human leucocyte antigen (HLA) class I molecule expression observed in non-Hodgkin's lymphomas (NHL), similarly to solid tumours, has been reported to favour tumoral escape from the immune system. In order to identify the underlying mechanisms, we analysed 15 HLA defective NHL including partial (n = 10) and total class I (n = 5) loss, as well as HLA class II defects (n = 5). The HLA defect concerned HLA-A and -B antigens in 14 of 15 cases.

Capacity of myeloid and plasmacytoid dendritic cells especially at mature stage to express and secrete HLA-G molecules.

Human leukocyte antigen (HLA-G), a class Ib major histocompatibility complex molecule, is potentially relevant in the immune response through its various immune cell functions. Its expression noticed in some malignancies has also been shown on macrophages and dendritic cells (DC) in tumoral and inflammatory diseases. As DC constitute a key component in the immune response, this work aimed at assessing the expression of HLA-G at transcriptional and proteic levels during differentiation and maturation of the different DC subsets.