Kunihiro Notake

Molecular cloning of the gene coding for the human T cell differentiation antigen CD7

The CD7 molecule is a differentiation antigen found on the surface of T lymphocytes and also on a very minor fraction of acute nonlymphocytic leukemia (ANLL). To study the genomic structure of the CD7 gene, two clones (SY4 and SY22) were isolated by screening a genomic library with a CD7 cDNA probe. Restriction mapping of these two phage clones showed that both overlapped each other, covering a total length of 23 kilobases (kb). Transfection of mouse L cells demonstrated that SY22 contains the gene expressing the CD7 antigen reactive with monoclonal CD7 antibody (Tp40), while SY4 does not. Subcloning of a 10.5 kb fragment from a 14.4 kb insert of SY22 contained the structural gene for the CD7 antigen. Detailed restriction mapping and partial sequence analysis revealed the CD7 gene to consist of four exons. By RNase protection assay, multiple initiation sites — 122 base pairs (bp) to — 38 bp from ATG translation initiation site were demonstrated. The promoter region had high G+C content and contained two SP1 binding sites (CCGCCC) and an AP2 binding site (CCCCAGGC), but lacked CAAT and TATA motifs.

Development and Regression of Shope Papillomas Induced in Newborn Domestic Rabbits

Summary Newborn domestic rabbits were inoculated at birth with Shope papil-loma virus and kept under observation for more than 6 months. Over 16 weeks were required for spontaneous regression and such was observed in only 7 out of 55 animals (13%). Serum antibodies against the papilloma virus and cells were elicited in these animals and skin reaction of the delayed type was also elicited against the virus. The low regression rate was not attributed, therefore, to immunological tolerance against the papilloma. Multiple papillomas were produced in some of the animals, but neither infectivity nor virus particles were detected in the papillomas. Thanks are due to M. Ohara for assistance with the manuscript.

A human monoclonal antibody recognizing a surface antigen on stomach cancer cells.

Lymph‐node lymphocytes of a patient with stomach cancer were fused with the mouse‐human heterohybridoma, HM‐S. A clonc (2F9) was isolated that showed stable production of an IgM antibody reactive with NUGC‐4 stomach cancer cell line. This antibody reacted predominantly with a cell surface antigen on cell lines originating from gastro‐intestinal cancer and adenocarcinoma of lung, whereas it was not generally reactive with other types of cancers, or with normal kidney cells or fibroblasts. Biotin‐labeled 2F9 antibody clearly stained cell smears and the nude mouse tumor of NUGC‐4, hut it did not show a positive reaction with stomach cancer tissues obtained from more than 10 patients, indicating that the antigen detected is very weakly expressed on tumor cells or on a limited number of stomach cancers. The antigen shed from NUGC‐4 cell line was detected in the culture supernatant. 2F9 antibody precipitated a glycoprotein with a molecular weight of over 200 kilodaltons as well as a possible glycolipid, from NUGC‐4 cells labeled with [3H]glucosamine or [35S]‐H2SO4. Periodic acid treatment of the tissue section decreased reactivity with 2F9 antibody, but heat, neuraminidase or protease treatment did not. These results suggested that the epitope is present on a carbohydrate moiety not containing sialic acid, and that a part of the antigen molecule is sulfated.

Production of a monoclonal antibody inhibiting the killer activity

We established the hybridoma producing the monoclonal antibody (mAb) 3C3 by immunizing rats with mouse natural killer (NK)-like cells. The 3C3 mAb seemed to react mainly with T cells and T-lineage cell lines. The 3C3 antigen also seemed to be coincidentally expressed on a part of asialo GM1+ cells from nude mice, suggesting its expression on NK cells. Treatment of effector cells with 3C3 mAb markedly inhibited the killer activity against RL male-1 cells, but less so against YAC-1 cells, in vitro. It is suggested that the cell surface molecule defined by 3C3 mAb was closely associated with the killer activity of T cells and NK cells.

Production of interleukin-2 by YAC-1 cells stimulated with interleukin-1 and its augmentation of the natural killer activity

The production of interleukin-2 (IL-2) by YAC-1 cells stimulated with interleukin-1 (IL-1) was examined in the in vitro culture system. The IL-2 activity was detectable in the culture supernatant of YAC-1 cells stimulated with either a mouse IL-1 preparation or human purified IL-1. This activity could be detected 1 h after stimulation with IL-1. The addition of monoclonal antibody reactive with mouse IL-2 receptor completely blocked the IL-2 activity in the culture supernatant of IL-1-stimulated YAC-1 cells. Further, the culture supernatant of IL-1-stimulated YAC-1 cells augmented the NK activity in mouse spleen cells. The role of the IL-2 activity in the culture supernatant of IL-1-stimulated YAC-1 cells on augmentation of the NK activity is discussed.

Detection of HPV infection by DNA-RNA hybridization and cytological findings.

ヒトパピローマウイルス (humam papilloma virus, HPV) のRNAプローブ (No.6, 11, 16, 18, 31, 33, 35の混合RNA) を用いて子宮頸部異形成上皮および子宮頸癌患者におけるHPVの感染の有無について検討した.1) HPV-DNA陽性はclass IIIa 4例中2例 (50%), class IIIb 4例中2例 (50%), class IV 2例中1例 (50%), class V 6例中2例 (33%) に認められた.したがって, class IIIa以上の16例中7例 (44%) にHPV-DNA陽性を認めた.2) 組織診とHPV-DNA陽性の検討では, 軽度異形上皮が1例中1例 (100%), 上皮内癌が7例中3例 (43%), 扁平上皮癌が7例中2例 (29%) であった.3) HPV-DNA陽性7例のうち, 細胞診上の特徴とされているkoilocytesは3例に認められた.4) 子宮癌検診を行った86例では85例がHPV-DNA陰性で, 細胞診はclass IおよびIIであり, 残る1例はHPV-DNA陽性であり, かつ細胞診の結果もIIIaであった.