TCR reconstitution in Jurkat reporter cells facilitates the identification of novel tumor antigens by cDNA expression cloning

The identification of novel tumor antigens is of extreme importance for effective immunotherapy against cancer. A major obstacle in this field is the limited life span of tumor-specific cytotoxic T lymphocytes (CTLs) in vitro. Therefore we searched for a method to isolate the tumor specificity of these CTLs, i.e., their T-cell receptors (TCRs) and transfer it to an immortalized T-cell line. For this purpose, a TCR-negative Jurkat T-cell line was equipped with a nuclear factor of activated T cells (NFAT)-luciferase reporter construct to allow measurement of TCR-mediated activation. To establish the feasibility of this tumor-specific TCR transduction, we cloned the TCR genes of a known T-cell clone specific for the tumor antigen CAMEL (CTL-recognized antigen on melanoma) into a retroviral construct. Jurkat reporter cells transduced with this construct, Jrt-TCRalpha3beta5, were tested for their reactivity against CAMEL-expressing melanoma cells, peptide-loaded T2 cells and CAMEL-transfected COS-1 cells. The melanoma cell lines were poorly recognized, but peptide-pulsed and -transfected cells effectively stimulated NFAT signaling. The activation of TCR(+) Jurkat reporter cells was shown to be dependent on the antigen density on the target cells and the expression level of the coreceptor CD8 on the Jurkat cells. To verify the benefit of this TCR reconstitution method for identification of novel antigens, pools of the cDNA library from which CAMEL was originally cloned were transfected in COS-1 cells and screened with Jrt-TCRalpha3beta5. Identical cDNA pools were found that were positive with these cells and with the CAMEL-specific CTL clone. Our results illustrate that TCR-reconstituted Jurkat reporter cells are a useful tool in the identification of novel tumor antigens by cDNA expression cloning.     

Desensitization of soluble guanylate cyclase in renal cortex during endotoxemia in mice

Acute endotoxemic renal failure involves renal vasoconstriction, which presumably occurs despite increased nitric oxide (NO) generation by inducible NO synthase in the kidney. The present study examined the hypothesis that the renal vasoconstriction during endotoxemia occurs in part because of desensitization of soluble guanylate cyclase (sGC). Endotoxic shock was induced in male B6/129F2/J mice by an intraperitoneal injection of Escherichia coli lipopolysaccharide. The endotoxemia resulted in shock and renal failure as evidenced by a decrease in mean arterial pressure and an increase in serum creatinine and urea nitrogen. Serum NO increased in a time-dependent manner, reaching the highest levels at 24 h, in parallel with induction of inducible NO synthase protein in the renal cortex. In renal cortical slices obtained from endotoxemic mice, cyclic guanosine monophosphate (cGMP) increased significantly at 6 h and 15 h as compared with control but normalized at 24 h after injection of lipopolysaccharide. Incubation of renal cortical slices in the presence of a phosphodiesterase inhibitor isobutylmethylxantine did not alter the pattern of changes in cGMP. Incubation of renal cortical slices with 2 mM sodium nitroprusside resulted in a similar accumulation of cGMP in slices taken from control and endotoxemic mice at 6 h and 15 h. However, in slices from 24-h endotoxemic mice, accumulation of cGMP in response to sodium nitroprusside was significantly lower. This lower stimulability of sGC was not paralleled by a decrease in its abundance in renal cortex on immunoblot. Taken together, these results demonstrate a desensitization of sGC in renal cortex during endotoxemia, which may contribute to the associated renal vasoconstriction.     

Comment on ‘Predicting recurrence in axillary node negative breast cancer patients’, by Rosner and Lane

on behalf of the Nottingham Breast Unit     

Establishment and characterization of 7 ovarian carcinoma cell lines and one granulosa tumor cell line: Growth features and cytogenetics

The characteristics of 7 newly established ovarian carcinoma cell lines and one granulosa tumor cell line obtained from tumor samples of 7 patients with varying histology of the primary tumor are reported. The cell lines were isolated from 5 serous carcinomas, a mucinous carcinoma, an endometrioid carcinoma and a granulosa cell tumor. All cell lines were passaged at least 25 times and showed stable growth rates. Colony-forming efficiency varied on plastic from 2 to 57% and in agar from 0.01 to 9.30%. The DNA index of the granulosa tumor cell line was diploid, while the ovarian carcinoma cell lines were all aneuploid. In 2 cell lines polyploidisation occurred during culturing. A thorough cytogenetic analysis of 7 cell lines revealed that the granulosa tumor cell line has only minor cytogenetic abnormalities (+5, 22_q+). In contrast, the epithelial ovarian-cancer cell lines gave very complex karyotypes with numerous markers and structurally rearranged chromosomes. The chromosomes most often in excess were 15 and 20. Structural rearrangements of chromosomes 1, 3, 7 and 11 were prominent in all ovarian cell lines. In addition, we found changes in chromosomes X, 5, 8 and 13 that have rarely been described before.     

Prevalence of behaviour disorders in low birthweight infants

OBJECTIVE--To determine the prevalence of behaviour disorders in low birthweight infants. DESIGN--Children of birth weight < or = 2000 g born to mothers resident in Merseyside in 1980-1 assessed using the Rutter parent and teacher behaviour questionnaires and the Conner modification of the Rutter teacher questionnaire. Children attending normal schools were assessed with controls matched for age, sex, and class in school. Children attending special schools were assessed unmatched. SUBJECTS--233 matched case-control pairs attending normal primary schools and 46 unmatched children attending special schools. SETTING--Primary and special schools. MAIN OUTCOME MEASURES--Emotional, conduct, and undifferentiated behaviour disorders and hyperactivity. RESULTS--On the parental questionnaire screen, 36% of the cases and 22% of the controls had a behaviour disorder and on the teacher questionnaire the proportions were 27% and 12% respectively. Hyperactivity was significantly more common among male cases than their controls (21% v 5.0%) but differed little among female cases and controls (9% v 7%). CONCLUSIONS--Improving neonatal survival of low birthweight infants is accompanied by a higher prevalence of behaviour disorders. The long term implications for psychiatric morbidity and other adult disease must be monitored.     

Effect of the Concurrent LHRH Antagonist Administration with a LHRH Superagonist in Rats

Purpose. The purpose of this study was to investigate the effect of anovel LHRH antagonist, Orntide acetate, on the initial testosteroneelevation in rats during treatment with a LHRH superagonist,Leuprolide acetate.Methods. Thirteen groups of a rat animal model were administeredeither liquid Orntide or Orntide PLGA microspheres before or simultaneouslywith Leuprolide injections. Serum levels of testosterone weremonitored during the time course of the study using a radioimmunoas say method.Results. Administration of a single daily dose of liquid Orntide resultedin testosterone suppression within 6 h to levels below 0.5 ng/ml(castration level). However, combined administration of liquid Orntide andliquid Leuprolide did not have a significant effect on the initialtestosterone elevation in studied rats. Similarly, there was no effect when liquidOrntide was co-administered with Leuprolide microspheres. Administrationof Orntide microspheres 48 h before Leuprolide microspheressuppressed testosterone levels below the castration level within 24 h,however, did not prevent a rise in testosterone serum concentration uponadministration of Leuprolide microspheres. Also, a second testosteronepeak was observed between days 3 and 15 in the animals which weresimultaneously treated with Orntide microspheres and Leuprolidemicrospheres.Conclusions. Orntide acetate was found to be an effective LHRHantagonist with a rapid onset of pharmacological action and a shortbiological half-life. Administration of a single dose of liquid Orntideor Orntide microspheres, resulted in rapid testosterone suppressionwithout an initial elevation, as seen with LHRH superagonists. However,combined administration of Orntide and Leuprolide did not havean effect on the initial testosterone elevation in rats.     

BENIGN GASTROCOLIC FISTULA ASSOCIATED WITH PERITONITIS

SUMMARY Gastrocolic fistula is most often related to malignancy or previous gastric surgery. It is an uncommon complication of benign gastric ulceration in patients who have not had a previous operation. Benign gastrocolic fistula associated with peritonitis is extremely rare — this case is only the fourth ever reported. The patient presented with an acute abdomen, and subsequent investigations demonstrated a gastrocolic fistula of benign aetiology.