YPT/rab proteins are ras-like small GTPbinding proteins that serve as key regulators of vesicular transport. The mRNA levels of two YPT/rab genes in pea plants are repressed by light, with the process mediated by phytochrome. Here, we examined the mRNA expression and the location of the two proteins, pra2-and pra3-encoded proteins, using monoclonal antibodies. The pra2 and pra3 mRNA levels were highest in the stems of dark-grown seedlings. The corresponding proteins were found in the cytosol and the membranes of the stems. Most of thepra2 protein was in the growing internodes, especially in the growing region, but the pra3 protein was widespread. These results suggest that the pra2 protein is important for vesicular transport in stems, possibly contributing to stem growth in the dark, and that the pra3 protein is important for general vesicular transport. The amounts of pra2 and pra3 proteins decreased with illumination. The decrease in these proteins may be related to the phytochrome-dependent inhibition of stem growth that occurs in etiolated pea seedlings.

These findings indicate that the AT2R gene may not play a major role in the development of renal hypoplasia and other CAKUT in humans, at least in the Japanese population.

A novel interleukin‐2 (IL‐2)‐dependent cell line, HANK1, was established from a patient with CD56+ NK/T‐cell lymphoma arising in the retroperitoneum. Morphologically, HANK1 is a pleomorphic large cell line with irregular nuclei, which contains azurophilic granules in the cytoplasm. Immunophenotypic analysis showed that HANK1 expressed CD2, CD3ɛ, CD56, TIA‐1, granzyme B, and HLA‐DR, but no other T‐lineage markers. These features were the same as seen in the original tumour, and are highly characteristic of nasal and ‘nasal‐type’ NK/T‐cell lymphoma as described in the proposed W.H.O. classification. Genotypically, this cell line also demonstrated the germline configuration of the T‐cell receptor β, γ and the immunoglobulin heavy chain genes and clonal integration of the Epstein‐Barr virus (EBV) together with antigen expression with a type II latency pattern (LMP‐1+ and EBNA2−). Furthermore, Southern blot analysis using the EBV termini as probes confirmed its derivation from the original lymphoma, and revealed that it contained multiple copies of the EBV genome. Dose‐dependent growth on IL‐2 was observed in an in vitro study with a doubling time of 3 d at maximal stimulation. These data indicate that HANK1 seemed to preserve the biological characteristics of the original tumour and therefore may serve as a good model for the further analysis of unusual ‘nasal‐type’ NK/T‐cell lymphoma.

Treatment with IDEC-C2B8 (C2B8), the chimeric anti-CD20 antibody, was shown in a phase I-II study to be very effective for the treatment of low-grade B-cell lymphoma, in contrast to the results of most previous immunotherapies with monoclonal antibodies. In a study designed to elucidate the reason for this efficacy, two cell lines derived from lymphomas with BCL2 gene rearrangement (SU-DHL-4 and SU-DHL-6) showed remarkable growth inhibition and cell-death, and two other cell lines derived from a diffuse lymphoma (RC-K8) and a mantle cell lymphoma (SP-49) showed moderate growth inhibition, but neither a CD20 weakly positive cell line (NALL-1) nor a negative cell line (MOLT-4) showed any growth inhibition. An examination of the intensity of cell-surface CD20 expression showed no correlation between intensity and degree of growth inhibition among the four cell lines showing growth inhibition. Morphological examination revealed condensed and fragmented nuclei and budding of the plasma membrane, both characteristic of apoptosis, with some cells in these cell lines showing growth inhibition by C2B8. Such apoptosis was also confirmed by flow cytometric analysis, suggesting that, at least in part, apoptosis plays a role in this growth inhibition. This growth-inhibitory mechanism may thus account for the effectiveness of C2B8 antibody therapy.

No abstract