Atsuo Noguchi

Transient Expression of CD20 Antigen (Pan B Cell Marker) in Activated Lymph Node T Cells

In contrast to the case of peripheral T cells, the surface expression of CD20 antigen and the expression of CD20 mRNA in monkey lymph node (LN) T cells underwent a noticeable increase when they were cultured with mitogen and interleukin‐2 (IL‐2). To confirm in vivo regulation of CD20 expression during the activation of LN T cells, we examined LNs derived from monkeys experimentally inoculated with simian immunodeficiency virus (SIV). Significant expression of CD20 antigen was detected in the T cells of the LNs at the stage of lymphadenopathy. These findings suggest that lymphocyte activation in the LNs induced expression of the CD20 molecule in some T cells.

Sequence analysis of DPB1-like genes in cynomolgus monkeys (Macaca fascicularis)

Two sequences o f Mafa-DPBl-like alleles o f the cynomolgus monkey major histocompatibil i ty complex were determined without using cloning techniques. In the present study, eight cynomolgus monkeys belonging to two families (Fig. 1) were selected f rom the Malaysian colonies at the Tsukuba Primate Center. Using the polymerase chain reaction (PCR)-SSCP method (Hoshino et al. 1992) with a pr imer set (Kimura and Sasazuki 1992) for the human DPB1 exon 2, two different homozygous patterns as well as several heterozygous patterns were identif ied (Fig. 1A, B). Subsequently, the two sequences o f the homozygous D N A s were determined using an automated D N A sequencer. The nucleotide sequences o f these two alleles (MafaDPB1*M25 and M09; Fig. 2) were closer to those o f human DPB1 alleles (the average percentage identity between the nucleotide sequences o f the two macaque alleles and those o f human alleles DPB1 *02011, 0401, and 0101 is 89%; Marsh and Bodmer 1991) than to the human DPB2 pseudogene (75%; Kapper and Strominger 1986). The findings obtained by compar ing the two macaque allele sequences were consistent with the observation that there are many more nonsynonymous than synonymous substitutions at the human HLADPB1 locus. The present results clearly demonstrate that cynomolgus monkeys have DPBl-l ike alleles. It is presumed, therefore, that macaques have at least one DPB1 locus and that nonsynonymous nucleotide substitutions are prevalent in the gene.

Silkworm haemolymph factor(s) interacting with vertebrates complement system

Two complement-related activities were found in the haemolymph of the silkworm, Bombyx mori. One was detected as a ‘classical C3-like’ activity (CC3LA) to cooperate with mammalian or anuran ‘classical R3’ reagent to induce enhanced lysis of rabbit IgM-rich haemolysin-sensitized sheep erythrocytes. Another is detected as an alternative pathway inhibiting activity (APIA). Silkworm haemolymph (SWHL) was fractioned by DEAE cellulose, CM cellulose and Sephadex G-200 chromatographies. In every step of the fractionation procedure, these two activities were eluted in the same regions, suggesting that these two activities are carried on a single factor.

Distribution of U5 antigen on lymphocyte subsets in human and nonhuman primates

The U5 monoclonal antibody developed by immunizing mice with Japanese monkey lymphocytes could react with lymphocytes of primate species including Old World monkeys, apes, and human. However, the distributions of U5 antigen on major functional subsets of lymphocytes were different in primate species. The U5 antigen was mainly distributed on natural killer (NK) cells in human, but on B cells in Old World monkeys. On the other hand, U5 antigen was detected on both B and NK cells in chimpanzees and gibbons, indicating that the distribution of U5 antigen on lymphocyte might change from B cells to NK cells during primate evolution.

Chromosome sorting of primates: Isolation and identification of Y chromosome in green monkeys

Single laser flow cytometry was applied to the karyotype analysis of green monkeys. Clear sex difference in flow karyotype was recognized in this monkey, because Y chromosome could be identified as a single peak in the histogram of male specimens. We could isolate Y chromosome of this species by the use of a cell sorter, and demonstrate by polymerase chain reaction that the sorted-out chromosomes contained the Y chromosome specific nucleotide sequence (SRY). This chromosome sorting technique provides a powerful strategy for constructing the DNA library specific to Y chromosome in this species.

Complement system in elasmobranchs

Abstract Serum of the Japanese smooth dogfish, Triakis scyllia , was nonhemolytic against rabbit red blood cells (RRBC) and sheep red blood cells (SRBC), but enhanced the activities of heterologous fish sera (sera from Orectolobus japonicus , Squalus mitsukurii and the carp, Cyprinus carpio ) to lyse red cells (RRBC or SRBC) except in case of RRBC- lysis by carp serum. Addition of sub-hemolytic concentration of Squalus or carp serum induced SRBC-lysing activity of Triakis serum. The reaction involved in this enhancement of RRBC (or SRBC)-lysis required divalent cations, Ca ++ and/or Mg ++ , and therefore a complement-like and direct red cell membrane attack by Triakis serum was strongly suggested. Zymosan-treated carp serum did not cooperate with Triakis serum to generate enhanced SRBC-lysis, which indicated a cooperative reaction between Triakis serum factor(s) and carp late complement component(s). Zymosan-treatment reduced the hemolytic activity of the carp serum, whereas it did not cause any detectable reduction in the hemolytic activity of Squalus and Orectolobus sera.

PROPERDIN-LIKE PATHWAY IN THE SERUM OF THE LAMPREY (LAMPETRA JAPONICA)

Publisher Summary Lamprey hemolytic system appears very different from gnathostome complement system. This chapter discusses a study to examine the properdin-like pathway in the serum of the lamprey (Lampetra japonica). Lamprey sera (LS) reacted with rabbit red cells (RRBC) through two successive steps. RRBC-lysis through these complements was inhibited by pretreatment of RRBC with LS, whereas no such Inhibition was observed for LS-treated EA. This difference between the results of RRBC and EA strongly suggest that some site(s) on RRBC capable of reacting with properdin system might be involved in the interaction between RRBC and LS. In the first step, factor X in LS reacted with RRBC, in the absence of divalent cations, to generate an intermediate complex, RRBC-X. In the second step, RRBC-X reacted with some other factor(s) in LS to further generate RRBC, and this step was Mg2+-dependent. Both RRBC and RRBC-X activated, but RRBC did not activate bullfrug complement in EGTA.GVB.2Mg2+. These results strongly suggested a primitive properdin or properdin-like system in the lamprey.