The miR-144/451eGFP allele, a novel tool for resolving the erythroid potential of hematopoietic precursors

A long outstanding problem is the resolution of the full potential of hematopoietic precursors. The commonly used allotypic marker Ly5 permits the tracing of lymphoid and granulocyte-macrophage (GM) output. Here we present a novel eGFP allele that allows the quantitative analysis of red blood cell (RBC) origin at the single-cell level. The miR-144/451 locus is required for erythroid development and homeostasis. Taking advantage of the fact that miR-451 is specifically and highly expressed in the erythroid lineage, we inserted an eGFP expression cassette into the miR-144/451 locus. In miR-144/451+/eGFP animals, accumulation of eGFP is exclusively observed during terminal erythroid differentiation. Expression of miR-144/451eGFP ignites immediately before the CFU-E stage and results in strong and complete labeling of all mature RBCs in circulation. Using competitive reconstitution experiments in the Ly5 transplant model, we show that eGFP linearly correlates with Ly5 expression. Thus, the miR-144/451eGFP allele represents a novel tool for the resolution of erythroid potential.

Human rheumatoid factor crossidiotypes. II. Primary structure-dependent crossreactive idiotype, PSL2-CRI, present on Wa monoclonal rheumatoid factors is present on Bla and other IgM kappa monoclonal autoantibodies.

The amino acid sequence of the L-CDR2 (complementarity-determining region) of Bla mRF (monoclonal rheumatoid factor) is identical to that of the Wa mRFs. The PSL2-CRI (crossreactive idiotype), as determined by anti-PSL2, which has been shown to be present on all Wa mRFs, is also present on the Bla mRF and other monoclonal autoantibodies. PSL2-CRI is, therefore, not unique to Wa mRFs and may be present on most IgM kappa monoclonal autoantibodies. Whether PSL2-CRI is a crossidiotype (XId) that is selectively present on autoantibodies or represents an allotypic marker for a V kappa III gene is undetermined.

Detection of polymorphic rat MHC antigen determinants in cryostat sections. A method for selecting monoclonal alloantibodies.

An immunohistological method for detection of rat MHC antigens by unconjugated primary alloantibodies is described. The procedure is based on secondary reagents specific for an allotypic marker of rat kappa light chains and makes possible differentiation between specifically bound alloantibody and the ubiquitously distributed interstitial immunoglobulin in the section. This technique can be used to pre-select monoclonal antibodies to be coupled to biotin or enzymes for histological application.

Gamma heavy chain disease: clinical aspects and characterization of a deleted, noncovalently linked gamma1 heavy chain dimer (BAZ)

This report describes the clinical and immunoglobulin features of a patient with gamma heavy chain disease (HCD), who presented with a clinical picture suggestive of an underlying malignancy rather than the usual picture of lymphoma or granulomatous disease. A unique clinical feature was the nearly total replacement of the submaxillary glands by plasma cells. The patient's serum and urine contained a paraprotein, gammaHCD protein BAZ, which belongs to the gamma1 subclass and forms noncovalently linked dimers with a molecular weight of approximately 60,000 daltons. This mutant protein exhibited a deletion which encompassed most of the variable (V) region, the first constant domain (CH 1), and the hinge region. In addition, preliminary structural analyses demonstrated the replacement of alanine by glycine in position 431 of the carboxyterminal octadecapeptide. This substitution may possibly represent another allotypic marker on IgG1 proteins.

Gamma heavy chain disease: clinical aspects and characterization of a deleted, noncovalently linked gamma1 heavy chain dimer (BAZ)

This report describes the clinical and immunoglobulin features of a patient with gamma heavy chain disease (HCD), who presented with a clinical picture suggestive of an underlying malignancy rather than the usual picture of lymphoma or granulomatous disease. A unique clinical feature was the nearly total replacement of the submaxillary glands by plasma cells. The patient's serum and urine contained a paraprotein, gammaHCD protein BAZ, which belongs to the gamma1 subclass and forms noncovalently linked dimers with a molecular weight of approximately 60,000 daltons. This mutant protein exhibited a deletion which encompassed most of the variable (V) region, the first constant domain (CH 1), and the hinge region. In addition, preliminary structural analyses demonstrated the replacement of alanine by glycine in position 431 of the carboxyterminal octadecapeptide. This substitution may possibly represent another allotypic marker on IgG1 proteins.