A phase II trial of murine monoclonal antibody 17-1A and interferon-γ: Clinical and immunological data

Summary A group of 15 patients with metastatic colorectal adenocarcinoma received a combination of interferon (0.1 mg/m², days 1–15) and the murine monoclonal antibody 17-1A (400 mg, days 5, 7, 9 and 12). The treatment was tolerated with minimal toxicity. Of the 14 evaluable patients, 13 developed human antibody to murine 17-1A, with 11 patients demonstrating antibody to the variable region of 17-1A (anti-idiotype). Antibody to the variable region was inhibited by 17-1A but not by mouse immunoglobulin. Sera from patients with substantial anti-idiotype reactivity were capable of inhibiting the binding of murine 17-1A to antigen expressing LS174-T cells thus indicating the presence of antibody directed against the 17-1A combining site (mirror-image anti-idiotype). The median survival of the whole group was 56 weeks and there was no correlation between clinical response/survival and the development of anti-idiotype antibody.Supported by the Veterans Administration Medical Center and by Public Health Services grant CA 45 232 from the National Cancer Institute, National Institutes of Health, Department of Health and Human Services     

The occurrence of polyenoic very long chain fatty acids with greater than 32 carbon atoms in molecular species of phosphatidylcholine in normal and peroxisome-deficient (Zellweger''s syndrome) brain.

The n-6 tetra- and pentaenoic fatty acids with carbon chain lengths greater than 32 found in normal brain are located predominantly in a separable species of phosphatidylcholine. A similar phospholipid is found in increased amounts in the brain of peroxisome-deficient (Zellweger's syndrome) patients, but the fatty acid composition differs in that penta- and hexaenoic derivatives predominate. Our data strongly suggest that the polyenoic very long chain fatty acids are confined to the sn-1 position of the glycerol moiety, while the sn-2 position is enriched in saturated, monounsaturated and polyunsaturated fatty acids with less than 24 carbon atoms. It is postulated that these unusual molecular species of phosphatidylcholine may play some, as yet undefined, role in brain physiology.     

Aerial Dispersal and Epiphytic Survival of Pseudomonas syringae during a Pretest for the Release of Genetically Engineered Strains into the Environment

Prospective experimental field evaluation of genetically engineered microorganisms, such as microbial pest control agents, raises issues of how to properly ascertain their fate and survival in the environment. Field trials with recombinant organisms must reflect requirements for sampling and monitoring. Field trials were conducted at Tulelake, Calif., to monitor the numbers of viable cells of a nonrecombinant strain of Pseudomonas syringae that entered the atmosphere and landed on plants and soil during and after an aerosol spray application. An exponential decrease in numbers of viable cells deposited at increasing distances from three sprayed plots was observed. The relative rate of survival of cells sprayed directly on plants was more than 10 times higher than that of cells dispersed through the air to similar adjacent plants. Results are being used to gain experience with the characteristics of a release site that influence containment or dispersal and to develop appropriate sampling methodologies for evaluating survival and dispersal characteristics of genetically engineered bacteria released into the environment. The ability to make predictions about microbial dispersal and survival will reduce the uncertainties associated with environmental releases of recombinant organisms.     

Lymphocyte recognition of lymph node high endothelium. VII. Cell surface proteins involved in adhesion defined by monoclonal anti-HEBFLN (A.11) antibody

Lymphocyte entry into lymph nodes (LN) and Peyer's patches (PP) occurs specifically at high endothelial cell venules (HEV). We previously isolated a high endothelial binding factor (HEBFLN) from rat lymph that blocked the lymphocyte binding sites of HEVLN but not HEVPP. In this study, mouse monoclonal anti-HEBFLN antibody (A.11) was used to investigate rat lymphocyte surface structures mediating adhesion to high endothelium. The A.11 antigen was expressed on the majority of thoracic duct lymphocytes (TDL), spleen, LN, PP cells, but was only detected on few (1 to 10%) thymus and bone marrow cells (indirect immunofluorescence). The treatment of TDL with the A.11 IgG blocked their ability to bind to HEVLN. This effect was specific, inasmuch as A.11 antibody did not block lymphocyte binding to HEVPP, and an anti-leukocyte-common antigen monoclonal antibody, OX1, did not block lymphocyte binding to HEVLN. In addition, the A.11 antigen isolated from the lymph and detergent lysates of TDL by antibody affinity chromatography had the capacity to block the lymphocyte binding sites of HEVLN but not HEVPP. Immunoprecipitation studies revealed that the A.11 antibody recognized the radioiodinated surface membrane proteins of TDL and TDL-derived T cells and B cells, which resolved with SDS-PAGE autoradiography into three polypeptides with relative m.w. of approximately 135,000, 63,000, and 40,000. We conclude that the A.11 antigen is a component of the lymphocyte surface recognition structure that mediates adhesion to high endothelial cells of rat peripheral lymph nodes.     

Mice coisogenically immunized against H-2 class I antigens on transfected l cells reject transplanted embryonal carcinoma cells

Evidence is presented of the ability of H-2 class I antigens to function as teratocarcinoma transplantation (Gt) antigens. Coisogenic immunization against H-2 class I antigens expressed on transfected L cells is shown to induce resistance to embryonic carcinoma (EC) cell allografts. The K^b, D^b, D^d, and, in appropriate recipients, L^d antigens can function as Gt antigens. The protocol presented may be useful for the molecular identification of other genes encoding histocompatibility antigens.     

Membrane adhesion in photosynthetic bacterial membranes. Light harvesting complex I (LHI) appears to be the main adhesion factor

We have reconstituted pigment-protein complexes isolated from Rhodopseudomonas palustris photosynthetic membranes into phospholipid liposomes. The various complexes were tested for their ability to promote adhesion of the liposome membrane in the presence and absence of Mg²⁺ ions. Samples containing a reaction center (RC)/light-harvesting I (LHI) complex appeared to stack in a manner resembling control thylakoids in 2 and 5 mM Mg²⁺. We also tested for the effects of Mg²⁺ on detergent extractablity of pigment-protein complexes from intact membranes. Mg²⁺ sharply reduced the amount of LHI solubilized from membranes, while having little effect on the extractability of the light harvesting II complex (LHII) and the RC. Based on these results we suggest that LHI is the principal adhesion factor of R. palustris thylakoids.Abbreviations LHC light harvesting complex - OG octyl glucoside - RC reaction center This paper is dedicated to Professor G. Drews on the occasion of his 60th birthday     

Role of protein synthesis in the survival of carbon-starved Escherichia coli K-12.

In a typical Escherichia coli K-12 culture starved for glucose, 50% of the cells lose viability in ca. 6 days (Reeve et al., J. Bacteriol. 157:758-763, 1984). Inhibition of protein synthesis by chloramphenicol resulted in a more rapid loss of viability in glucose-starved E. coli K-12 cultures. The more chloramphenicol added (i.e., the more protein synthesis was inhibited) and the earlier during starvation it was added, the greater was its effect on culture viability. Chloramphenicol was found to have the same effect on a relA strain as on an isogenic relA+ strain of E. coli. Addition of the amino acid analogs S-2-aminoethylcysteine, 7-azatryptophan, and p-fluorophenylalanine to carbon-starved cultures to induce synthesis of abnormal proteins had an effect on viability similar to that observed when 50 micrograms of chloramphenicol per ml was added at zero time for starvation. Both chloramphenicol and the amino acid analogs had delayed effects on viability, compared with their effects on synthesis of normal proteins. The need for protein synthesis did not arise from cryptic growth, since no cryptic growth of the starving cells was observed under the conditions used. From these and previous results obtained from work with peptidase-deficient mutants of E. coli K-12 and Salmonella typhimurium LT2 (Reeve et al., J. Bacteriol. 157:758-763, 1984), we concluded that a number of survival-related proteins are synthesized by E. coli K-12 cells as a response to carbon starvation. These proteins are largely synthesized during the early hours of starvation, but their continued activity is required for long-term survival.