Isolation and Identification of Cellulose-Binding Proteins from Sheep Rumen Contents▿

To extend our understanding of the mechanisms of plant cell wall degradation in the rumen, cellulose-binding proteins (CBPs) from the contents of a sheep rumen were directly isolated and identified using a metaproteomics approach. The rumen CBPs were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and some CBPs revealed endoglucanase activities toward carboxymethyl cellulose. Using mass spectrometry analyses, four CBPs were identified and annotated as known proteins from the predominant rumen cellulolytic bacterium Fibrobacter succinogenes: tetratricopeptide repeat domain protein, OmpA family protein, fibro-slime domain protein, and cellulose-binding endoglucanase F (EGF). Another CBP was identified as the cellulosomal glycosyl hydrolase family 6 exoglucanase, Cel6A, of Piromyces equi. F. succinogenes cells expressing EGF were found to be major members of the bacterial community on the surface or at the inner surface of hay stems by immunohistochemical analyses using anti-EGF antibody. The finding that four of the five CBPs isolated and identified from sheep rumen contents were from F. succinogenes indicates that F. succinogenes is significantly involved in cellulose degradation in the rumen

IgE Plasma Cell Leukemia Harboring t(11;14) and 1q Amplification

IgE plasma cell neoplasm is the rarest subtype of plasma cell neoplasms and is known for its poor prognosis and high incidence of t(11;14). However, t(11;14) has been classified as a standard-risk rather than high-risk cytogenetic abnormality in multiple myeloma. We have been unable to explain the discrepancy that the hallmark of IgE plasma cell neoplasm with a poor prognosis is a standard-risk cytogenetic abnormality. Here, we report a case of IgE primary plasma cell leukemia with extramedullary lesions of the liver, stomach, and lymph nodes. Plasma cell infiltration was pathologically confirmed in each organ. Cytogenetic analysis of plasma cells revealed t(11;14) and amplification of 1q21. Chemotherapy, with immunomodulatory imide drugs, proteasome inhibitors, and CD38 antibodies, was unsuccessful. In IgE plasma cell neoplasm, coexistence of other cytogenetic abnormalities with t(11;14) may be important. Investigating the presence of cytogenetic abnormalities coexisting with t(11;14) is not only useful for evaluating prognosis but also important for understanding the pathogenesis of the disease. Recently, venetoclax, an oral BCL2 inhibitor, has demonstrated promising efficacy in plasma cell neoplasm patients harboring t(11;14). Development of an effective venetoclax-based regimen for treating aggressive IgE plasma cell neoplasm with t(11;14) is expected