[Dot hybridization with synthetic oligonucleotide; analysis of point mutation of c-ras genes].
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Animals↗
Biomedical subjects
H Shiku
Publications and source records attributed to H Shiku.
Rat cytotoxic T lymphocytes against human T-lymphotropic virus type 1-infected cells recognize gag gene and env gene encoded antigens.
T cell immune responses in syngeneic WKA/H rats were analyzed by using lymphoid cell lines, TARS-1, TART-1, and TARL-2, infected with human T-lymphotropic virus type 1 (HTLV-1). Spleen cells of rats in which these cell lines had been rejected were sensitized in vitro with the same cell lines, and cells cytotoxic to these HTLV-1+ cell lines, and cells cytotoxic to these HTLV-1+ cell lines were generated. The effector cells were CTL of the CD5+ CD8+ phenotype and showed restriction of MHC class I Ag. Direct tests as well as cold target cell inhibition tests with an array of cell populations showed that these CTL reacted only with syngeneic HTLV-1+ cell lines. When xenogeneic HTLV-1+ cell lines were similarly utilized for in vitro sensitization, rat CTL specific for syngeneic HTLV-1+ cells were generated. They were not, however, reactive with xenogeneic HTLV-1+ cells used for sensitization. Syngeneic rat cells selectively expressing gag, env, or pX gene coded Ag were prepared by infection of recombinant vaccinia viruses. In cold target cell inhibition tests of anti-HTLV-1 CTL with thus prepared cells, cytotoxicity against the syngeneic HTLV-1+ cells line, TARS-1, was inhibited by syngeneic cells expressing gag gene or env gene coded Ag. Inhibition was, however, more consistent and more dominant by cells with gag gene than those with env gene. Syngeneic cells with pX gene and MHC class I incompatible cells with gag, env, or pX gene did not inhibit cytotoxicity.
Animals↗
Correlation of c-myc expression with nuclear pleomorphism in human renal cell carcinoma.
The expression of the c-myc gene product in renal cell carcinomas was examined by immunostaining with monoclonal antibody (mAb) MYC-1. The effects of preservation and fixation of tissues on staining were first examined. In cryostat sections fixed with 4% buffered formalin for 15 min, staining was observed in the nucleus. On the other hand, in paraffin sections after fixation with 10% formalin, staining was observed in the cytoplasm, but not in the nucleus. Because c-myc protein has been shown to be a nuclear protein, the finding that c-myc protein was not detectable in the nucleus appeared to be due to the preservation or fixation procedures used. Therefore, cryostat sections fixed with 4% formalin were used to investigate the correlation between the reaction of MYC-1 mAb and nuclear pleomorphism in primary and metastatic renal cell carcinomas. Among 41 primary tumors, positive staining was observed in 2 of 17 tumors (12%) of grade 1, 17 of 21 (81%) of grade 2, and all 3 (100%) of grade 3. Among 17 metastatic tumors, positive staining was not observed in any of the 5 (0%) of grade 1 but was observed in 2 of 4 (50%) of grade 2 and all 8 (100%) of grade 3. Thus, the frequency of the positive reaction with MYC-1 mAb was correlated with nuclear pleomorphism in primary and metastatic renal cell carcinomas. The reaction of Ki-67 mAb, which recognized a nuclear antigen present in proliferating cells, was also correlated with nuclear pleomorphism. These findings suggest that the c-myc gene product plays a role in cell proliferation in renal cell carcinomas.
Antibodies, Monoclonal↗
Isolation of an IgH gene circular DNA clone from human bone marrow.
Circular DNA was obtained from human bone marrow. Then a phage library was prepared and screened by use of two probes of the IgH gene; 5'-DHQ52, containing the 5' flanking region of DHQ52, and JH4.3, containing the sequence from JH3 to the 3' flanking region of JH6. One clone, HBMC-1, that was DHQ52+JH4.3- was obtained. HBMC-1 had the germline IgH region upstream of JH1 and the 3' flanking region of DXP1. A recombination signal sequence flanking the 5' side of the JH1 segment was attached to the recombination signal sequence flanking the 3' side of DXP1 forming a head-to-head structure of two 7mers with 10 nucleotides in-between. HBMC-1 is thus considered to be a circular DNA deleted as a consequence of DXP1-JH1 joining of the IgH gene.
Base Sequence↗
Localization and subcellular distribution of cellular ras gene products in rat brain.
Localization and subcellular distribution of the cellular ras gene products (c-ras p21s) in rat brain were studied by immunofluorescence and immunoblotting using a monoclonal antibody recognizing all of Ki-, Ha- and N-ras p21s. In immunohistochemical analysis, strong immunoreactivity for ras p21s was observed in the neuropile of cerebral and cerebellar cortex. On the other hand, the immunoreactivity of the neuronal perikarya and that of white matter were weak and that of non-neuronal cells was undetectable. In subcellular fractionation analysis of cerebrum, c-ras p21s were found mostly in the particulate fractions and almost half of the particulate-bound c-ras p21s were recovered in the P2 fraction containing myelin, synaptosomes and mitochondria, approximately one-third were in the P3 fraction containing microsomes, and the rest were in the P1 fraction containing nuclei and cell debris. In further fractionation of the P2 fraction, most of c-ras p21s were associated with synaptosomal fraction. In the synaptosomal fraction, c-ras p21s were highly concentrated in the fractions rich in synaptic plasma membranes and were poorly present in the other fractions rich in synaptic vesicles, intrasynaptosomal mitochondria or postsynaptic densities. The content of c-ras p21s of the original homogenate was calculated to be 0.05% of the total protein and c-ras p21s were distributed in the fractions rich in synaptic plasma membranes with approximately 4-fold enrichment over the original homogenate. These results indicate that c-ras p21s are mainly localized in the synaptic plasma membranes and microsomes and suggest that they may participate in some specific neuronal functions at these sites.
Animals↗
Proliferative response of cloned CTL line 10B-5 upon stimulation with soluble clonotypic monoclonal antibody and its blocking by anti-Lyt-2 antibody.
Proliferation of the cloned cytotoxic T lymphocyte (CTL) line 10B-5 induced by anticlonotypic antibody and its blocking by anti-Lyt-2 mAb were studied. Clone 10B-5 was derived from spleen cells of a (BALB/c x C57BL/6)F1, (CB6F1)-nu/+ mouse immunized with UV female 1 sarcoma. 10B-5 cells lysed UV female 1 specifically and proliferated upon stimulation with UV female 1 and feeder cells in the presence of IL 2. Anti-clonotypic monoclonal antibody (mAb) N1-56 was produced by a hybridoma established by fusion of spleen cells from a CB6F1-nu/+ mouse that had been immunized by five injections of 10B-5 cells prefixed with 0.1% formaldehyde. N1-56 mAb immunoprecipitated 90 kd molecules cleavable to 45 kd molecules under reducing conditions, indicating its reaction with T cell antigen receptor (TCR). N1-56 mAb in its soluble form induced a proliferative response of 10B-5 cells. Thus, the antigen binding site of N1-56 mAb appeared to substitute for the specific antigen determinant on UV female 1 sarcoma. The F(ab')2, but not the Fab fragment of purified N1-56 mAb, stimulated proliferation, indicating that cross-linking of TCR molecules was necessary for stimulation. The proliferative response of 10B-5 cells induced by soluble N1-56 mAb was blocked by addition of anti-Lyt-2.2 mAb to the cultures. The specificity of Lyt-2 blocking was confirmed by an absorption test. The proliferative response of 10B-5 cells induced by Con A, but not that induced by IL 2, was blocked by anti-Lyt-2.2 mAb. These results indicated that blocking by anti-Lyt-2.2 mAb was at an early stage and that it could be bypassed by stimulation with IL2.
Animals↗
Preferential usage of JH2 in D-J joinings with DQ52 in murine lymphocytes.
Southern blot analysis of genomic DNA of normal mouse thymocytes with a JH4 probe, a probe for JH4 of Igh genes, consistently showed a second band in addition to a germline band. The same band was also observed in analysis with a 5' DQ probe, a 5'-flanking sequence of DQ52, thus suggesting the use of DQ52. By analyzing EcoRI- and PvuII-digested genomic DNA, the above-observed band was demonstrated to be the result of DQ52-JH2 joining. This was further confirmed utilizing a T cell leukemia line with known DQ52-JH joinings. We then quantitatively estimated the frequencies of JH segment usages in joining with DQ52, through plaque hybridization assays. Three hundred and fifty JH4-positive clones were obtained from 7 x 10(5) plaques by plaque hybridization. Forty-eight randomly selected non-germline clones were purified and the use of JH segments was determined through Southern blot analysis. Nine clones used JH1, 29 used JH2, 9 used JH3, and 1 used JH4, thus indicating an apparent preferential usage of JH2 segment. Southern blot analysis of genomic DNA of progenitor B cells in culture showed a dominant band of DQ52-JH2 joining 1 week after initiation of culture. This may indicate that the dominant DQ52-JH2 joining in thymocytes is representative of early D-J joinings in progenitor B cells.
Animals↗
The role of CD8+ and CD4+ cells in rejection of multiple minor H-disparate skin grafts.
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Animals↗
The roles of CD8+ and CD4+ cells in tumor rejection.
In vivo administrations of anti-Lyt-2.2 (CD8) mAb and anti-L3T4 (CD4) mAb selectively eliminated CD8+ cells and CD4+ cells, respectively. The relative potencies of CD8+ cells and CD4+ cells and their roles in primary tumor rejections were studied by investigating the effects of these mAbs on tumor growth. CD8+ cells were themselves fully capable of mediating rejection in 5 different tumor rejection systems: two radiation leukemia virus (RadLV)-induced leukemias, B6RV2 and BALBRVD, a radiation-induced leukemia BALBRL male 1, and a plasmacytoma BALBMOPC-70A in CB6F1 mice, and a Friend virus-induced leukemia B6FBL-3 in B6 mice. On the other hand, CD4+ cells were capable of resisting tumor growth of B6FBL-3, but not of the other four tumors. Furthermore, for efficient rejection of CB6F1UV female 1 sarcoma by CB6F1 mice, synergy of CD8+ and CD4+ cells was necessary. Blocking of UV female 1 rejection was abrogated by delayed administration of anti-L3T4 (CD4) mAb but not anti-Lyt-2.2 (CD8) mAb, indicating the involvement of CD4+ cells in only the initial phase of rejection.
Animals↗
Increased expression of ras genes in non-Hodgkin's lymphomas is not associated with oncogenic activation of those genes by point mutation.
Twenty-three cases of non-Hodgkin's lymphoma (NHL) were analyzed for expression of ras genes by in situ hybridization utilizing biotinylated DNA probes. Increased expression of Ki-ras, Ha-ras and N-ras genes was observed in 12 cases, 6 cases and 1 case of NHL, respectively. Genomic DNA extracted from these 23 cases of NHL was region-specifically amplified by means of polymerase chain reaction to examine the presence of point mutations at the 12th, 13th and 61st codons of Ki-, Ha- and N-ras genes. Dot hybridization assays with appropriate oligonucleotide probes showed no evidence of point mutation in any case of NHL examined. These results indicate that increased expression of ras genes in NHL is not associated with ras gene activation by point mutation.
Base Sequence↗
Diversity of cellular molecules in human cells detected by monoclonal antibodies reactive with c-myc proteins produced in Escherichia coli.
Six clones of monoclonal antibodies, MYC-1 to -6, were prepared by using two kinds of truncated c-myc proteins, p23 and p42, produced in Escherichia coli as immunogens. Analysis with enzyme-linked immunosorbent assays and immunoblotting assays with peptides produced in Escherichia coli showed that 5 clones of monoclonal antibodies, MYC-1 to -4 and -6, were reactive with c-myc protein encoded by exon 2. The remaining one clone, MYC-5, was reactive with the portion of c-myc protein encoded by exon 3. All monoclonal antibodies were also reactive with phosphorylated c-myc protein produced by insect cells infected by the baculovirus expression vector with the human c-myc gene. With immunoblotting assays using cellular lysates, MYC-1 and -3 detected bands at the levels of 58 kDa and 60 kDa, MYC-5 detected a band at 56 kDa and MYC-6 detected bands at 68 kDa and 75 kDa. All of these bands were detectable in nuclear extracts of HL-60 and Colo320, both of which have amplified c-myc genes, and also the extract of RmycYl which is the c-myc gene transfectant into 3Yl rat cells. None of them was detectable in peripheral blood mononuclear cells and 3Yl, both of which lacked activated c-myc genes. This indicates that these nuclear proteins are either c-myc gene products or molecules closely related to the c-myc gene. The remaining two clones, MYC-2 and -4, detected a band at the level of 85 kDa in cytoplasmic extracts of all the above-mentioned cells independent of the presence of the c-myc gene. This suggests that 85 kDa protein might be irrelevant to the c-myc gene. The 56 kDa protein was detectable by MYC-5 in phytohemagglutinin-stimulated peripheral blood mononuclear cells as well as leukemic cells of some patients.
Animals↗
Adult T cell leukaemia cells are of CD4+ CDw29+ T cell origin and secrete a B cell differentiation factor.
Cells from six cases of adult T cell leukaemia were studied with respect to phenotypical and functional features. All cells were reactive with anti-CD4 and anti-CDw29 monoclonal antibodies (antibody against helper inducer T cells) but were unreactive with anti-CD45R monoclonal antibody (antibody against suppressor inducer T cells). Functionally, these cells secreted a B cell differentiation factor detected by SKW6-CL4 cell differentiation to IgM-producing cells, this secretion being enhanced by culture with recombinant IL-2. Though these results indicate that adult T cell leukaemia cells are of mature helper inducer T cell origin, these cells strongly suppressed PWM-induced B cell differentiation in the absence of CD8+ suppressor effector T cells.
Aged↗
Blocking of cytotoxic T-cell function of MOLF/Ei mice by anti-Ly 35.1 monoclonal antibody.
Ly 35.1 antigen is an alloantigen expressed only on T cells of Mus musculus molossinus-derived inbred strains. Previous findings indicated that the genetic locus coding for Ly 35 antigen was closely linked to Ly 2/3 on chromosome 6 and that epitopes detected by Ly 2.1 and Ly 35.1 monoclonal antibodies (mAb) were closely associated, as shown by binding inhibition assay. In this study, we examined the blocking effects of anti-Ly 2.1 and anti-Ly 35.1 mAb on cytotoxic T-cell function of MOLF/Ei mice generated against BALB/c. MOLF/Ei cytotoxicity was blocked by Ly 35.1 mAb, but not by anti-Ly 2.1 mAb. Additional tests showed that cytotoxicity was blocked by Ly 3.1 mAb, but not Ly 3.2 or Ly 2.2 mAb. These results suggested that MOLF/Ei mice express Ly 3.1, but not Ly 2.1 antigen at a functional level, and that Ly 35.1 may be a functional epitope of Ly 2 antigen in the MOLF/Ei strain.
Animals↗
Effector mechanism of H-Y and non-H-2 incompatible skin graft rejection in mice.
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Animals↗
Effector cells of lethal graft-versus-host disease (GVHD) in nude mice.
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Animals↗
Anti-idiotypic antibodies against UV-induced tumor-specific CTL clones. Preparation in syngeneic combination.
In this study, we first established several CTL clones of (BALB/c x C57BL/6)F1 origin that were specific for either syngeneic UV female 1 or UV male 1 fibrosarcoma cell lines. All the CTL clones had Thy-1+ Lyt-2+ L3T4- phenotypes and showed Kd restriction when lysing the corresponding target cells. Sera obtained from syngeneic animals immunized with three CTL clones, 10B-5 for UV female 1, and CTL9 and CTL10 for UV male 1, showed specific inhibition of target cell lysis with the corresponding CTL clones. The inhibitory activities were found in sera of the majority of immunized animals. Because the inhibitory activity resides in protein A-binding fraction, mAb were produced by hybridizing spleen cells of hyperimmune animals. N1-56 was thus obtained from a mouse immunized with 10B-5 CTL clone reactive with UV female 1. N1-56 was clonotype specific, reacting with 10B-5 but not with other CTL lines or leukemia cell lines. No N1-56+ cells were detectable in thymocytes, lymph node cells, or spleen cells of either naive or UV female 1-immune CB6F1 mice. Immunoprecipitation showed that N1-56 reacts with 90,000 Mr molecules on 10B-5 CTL clone under nonreducing conditions and 45,000 Mr molecules under reducing conditions, indicating its reactivities with idiotypic determinants of TCR on the CTL clone. N1-56 inhibited lytic activity of 10B-5, but neither N1-56 nor alpha-10B-5 hyperimmune serum inhibited that of alpha-UV female 1 mixed lymphocyte tumor cell culture cells. N1-56 induced proliferation of 10B-5 without addition of Ag.
Animals↗
Production of a truncated human c-myc protein which binds to DNA.
Two kinds of truncated human c-myc proteins were produced in Escherichia coli. The human c-myc gene is composed of three exons, exons 2 and 3 having coding capacity for a protein of 439 amino acids. 252 N-terminal amino acids are encoded by exon 2, the C-terminal 187 amino acids being encoded by exon 3. One of the proteins (p42) produced in E. coli corresponds to 342 amino acids from the 98th Gln to the C-terminus, plus 21 amino acids derived from the H-ras gene at the N-terminus. The other (p23) corresponds to 155 amino acids from the 98th Gln to the 252nd Ser, plus five amino acids (Gly-Gly-Thr-Arg-Arg) at the C-terminus, plus 21 amino acids from the H-ras gene at the N-terminus. The p23 protein was produced by using cDNA in which a frame shift occurred at the boundary between exons 2 and 3. We investigated the DNA-binding activity in p42 and p23 proteins. DNA-cellulose column chromatography showed that p42 binds to DNA, whereas p23 does not. This DNA-binding activity of p42 was inhibited by antiserum prepared against p42 but not by antiserum against p23. This indicates that the DNA-binding activity of c-myc protein is localized in the portion encoded by exon 3.
Cloning, Molecular↗
Expression of c-myc oncogene product and ras family oncogene products in various human malignant lymphomas defined by immunohistochemical techniques.
The authors studied the expression of c-myc and ras family oncogene products in 43 cases of malignant lymphoma (ML) using the immunoperoxidase method. Unfixed frozen sections of lymph nodes from four patients with Hodgkin's disease and 39 with non-Hodgkin's lymphoma, together with normal lymph nodes, were studied by the avidin-biotin-peroxidase complex (ABC) technique. Two monoclonal antibodies, MYC-2 raised against recombinant human c-myc protein (reacting specifically with the c-myc products P62 and P67) and RASK-4 (raised against recombinant P21 and reacting specifically with ras-family product P21) were used. The c-myc product was detected in nuclei of ML cells and some normal, mainly germinal center, lymphocytes. When the staining intensity shown by normal germinal-center lymphocytes was graded as positive (+) or weakly positive (+/-), a very intensely positive reaction ( to ++) was observed in 37 cases (86%) of ML, a positive reaction (+) in four cases (9.3%), and a weakly positive reaction (+/-) in two cases (4.7%). The ras family oncogene product reaction was intensely positive (++) in two cases (4.7%), positive (+) in 16 cases (37.2%), weakly positive (+/-) in 13 cases (30.2%), and negative in 12 cases (27.9%). Western blot analysis confirmed an elevated level of c-myc products in two cases, which showed intense MYC-2 staining, and of ras family products in one case, which demonstrated intense RASK-4 staining. The enhanced expression of these gene products may play an important role in lymphomagenesis of such cases.
Antibodies, Monoclonal↗