Multiple myeloma (MM) is a deadly, incurable malignancy in which antibody-secreting plasma cells (PCs) become neoplastic. Previous studies have shown that the PC niche plays a role cancer progression. Bone marrow (BM) cores from MM and a premalignant condition known as monoclonal gammopathy of unknown significance (MGUS) patients were analyzed with confocal and transmission electron microscopy. The BM aspirates from these patients were used to generate 3D PC cultures. These in vitro cultures were then assayed for the molecular, cellular, and ultrastructural hallmarks of dysfunctional PC at days 1 and 5. In vivo, evidence of PC endoplasmic reticulum stress was found in both MM and MGUS BM; however, evidence of PC autophagy was found only in MM BM. Analysis of in vitro cultures found that MM PC can survive and maintain a differentiated phenotype over an unprecedented 5 days, had higher levels of paraprotein production when compared to MGUS-derived cultures, and showed evidence of PC autophagy as well. Increased fibronectin deposition around PC associated with disease severity and autophagy dysregulation was also observed. 3D cultures constructed from BM aspirates from MGUS and MM patients allow for long-term culture of functional PC while maintaining their distinct morphological phenotypes.

The cellular mucosal and systemic effectors of gilthead sea bream (GSB) (Sparus aurata) involved in the acute immune response to the intestinal parasite Enteromyxum leei were studied in fish experimentally infected by the anal route. In the intestinal inflammatory infiltrates and in lymphohaematopoietic organs (head kidney and spleen) of parasitized fish, the number of plasma cells, B cells (IgM immunoreactive) and mast cells (histamine immunoreactive) were significantly higher, whereas the number of acidophilic granulocytes (G7 immunoreactive) decreased, compared with non-parasitized and unexposed fish. These differences were stronger at the posterior intestine, the main target of the parasite, and no differences were found in the thymus. In non-parasitized GSB, the percentage of splenic surface occupied by melanomacrophage centres was significantly higher. These results suggest that the cellular response of GSB to E. leei includes proliferation of leukocytes in lymphohaematopoietic organs and recruitment into intestines via blood circulation involving elements of innate and adaptive immunity. Acidophilic granulocytes and mast cells presented opposite patterns of response to the parasite infection, with an overall depletion of the former and an increased amount of the latter. Some differences between both cell types were also detected in regard to their granule density and cell morphology.

Th2-biased inflammation with eosinophilia and IgE production is a hallmark of helminth infections. It is pronounced in hyperreactive onchocerciasis patients (‘sowda’ or ‘local form’), who efficiently kill microfilariae resulting in severe dermatitis and lymphadenitis. In contrast, hyporeactive patients (‘generalised form’) tolerate high microfilarial loads. This is thought to be mediated by regulatory CD4+ T cells and macrophages producing suppressive cytokines such as IL-10 and transforming growth factor-beta (TGF-β). We investigated whether hyperreactivity was reflected by lower local TGF-β production, analysing stable latent TGF-β1 expression in onchocercomas, lymph nodes and skin from hyperreactive and hyporeactive patients by immunohistochemistry. TGF-β expression was compared with that of IgE, IgG1, IgG4, and the antigen-presenting, CD4+ T cell-inducing MHC class II molecule HLA-DR. TGF-β was weakly and less frequently expressed by various cell types in onchocercomas, skin and lymph nodes from hyperreactive compared to hyporeactive patients. This applied to reactions around living and dead adult worms as well as dead microfilariae. Antigen-presenting cells strongly expressed HLA-DR in both forms, but their numbers were reduced in hyperreactive nodules. Plasma cells produced more IgE and IgG1, but less of the anti-inflammatory antibody IgG4 in hyperreactive onchocercomas. In conclusion, hyperreactivity is linked with reduced local expression of TGF-β, HLA-DR and IgG4, which might contribute to the insufficient down-regulation of inflammation via TGF-β- and HLA-DR-induced regulatory lymphocytes.

A case of chronic, fluctuating plasma cell gingivostomatitis that progressed despite chemotherapy and surgery is reported. This is the first case reported of treatment with radiation therapy, and one of the few cases reported where the infiltrate has reached the larynx. After receiving low dose radiation therapy, via a conformal technique encompassing the respiratory mucosal lining from the base of tongue to carina, there has been symptomatic improvement.

We developed a two-step purification of mammalian polyadenylation complexes assembled in vitro. Biotinylated pre-mRNAs containing viral or immunoglobulin poly(A) sites were incubated with nuclear extracts prepared from mouse myeloma cells under conditions permissive for in vitro cleavage and polyadenylation and the mixture was fractionated by gel filtration; complexes containing biotinylated pre-mRNA and bound proteins were affinity purified on avidin-agarose resin. Western analysis of known components of the polyadenylation complex demonstrated copurification of polyadenylation factors with poly(A) site-containing RNA but not with control RNA substrates containing either no polyadenylation signals or a point mutation of the AAUAAA polyadenylation signal. Polyadenylation complexes that were assembled on exogenous RNA eluted from the Sephacryl column in fractions consistent with their size range extending from 2 to 4 × 106Mr. Complexes endogenous to the extract were of approximately the same apparent size, but more heterogeneous in distribution. This method can be used to study polyadenylation/cleavage complexes that may form upon a number of different RNA sequences, an important step towards defining which factors might differentially associate with specific RNAs.