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C D Porter

Publications and source records attributed to C D Porter.

36 records · Page 2Linked to original sources
PubMed1994

Generation of interleukin-2-secreting melanoma cell populations from resected metastatic tumors.

This study aimed to determine the feasibility of producing patient-specific, interleukin-2 (IL-2)-secreting tumor cell vaccines for the treatment of metastatic melanoma. Primary tumor cell cultures were established from 26/33 resected metastatic melanoma samples. Recombinant retroviral gene transfer and expression in these cultures was optimized using an amphotropic, defective retrovirus carrying the LacZ gene. All cell cultures were infectable; those that proliferated more rapidly were infected at a higher frequency. Addition of fibroblast growth factor to the culture medium increased the rate of cell proliferation and the efficiency of infection. A single infection with an identical retrovirus carrying a human IL-2 cDNA resulted in the generation of unselected cell populations secreting up to 300 units IL-2/10(6) cells.48 hr. Multiple infections increased the level of IL-2 secretion to 5,000 units/10(6) cells.48 hr. The recombinant viral genome could be detected at approximately single copy in the multiply infected cells; no helper virus was detected. IL-2 secretion from infected cultures was maintained following cryopreservation and x-irradiation. These data demonstrate that heterogeneous tumor cell populations secreting IL-2 can be generated from individual patients to be used as autologous, irradiated cell vaccines.

DNA, Neoplasm↗
PubMed1993

X-linked chronic granulomatous disease: correction of NADPH oxidase defect by retrovirus-mediated expression of gp91-phox.

Chronic granulomatous disease (CGD) is an inherited immunodeficiency resulting from the inability of an individual's phagocytes to produce superoxide anions because of defective NADPH oxidase. The disease may be treated by bone marrow transplantation and as such is a candidate for somatic gene therapy. Two thirds of patients have defects in an X-linked gene (X-CGD) encoding gp91-phox, the large subunit of the membrane cytochrome b-245 component of NADPH oxidase. Epstein-Barr virus-transformed B-cell lines from patients with CGD provide a model system for the disease. We have used retrovirus-mediated expression of gp91-phox to reconstitute functionally NADPH oxidase activity in B-cell lines from three unrelated patients with X-CGD. The protein is glycosylated and membrane associated, and the reconstituted oxidase is appropriately activated via protein kinase C. The kinetics of superoxide production by such reconstituted cells is similar to that of normal B-cell lines. These data show the potential of gene therapy for this disease.

B-Lymphocytes↗
PubMed1992

Superoxide production by normal and chronic granulomatous disease (CGD) patient-derived EBV-transformed B cell lines measured by chemiluminescence-based assays.

We have compared assays for products of the neutrophil respiratory burst in normal EBV-transformed B cell lines stimulated with agonists of protein kinase C. Those measuring O2- directly or its immediate product, H2O2, were successful. Of these, the most sensitive were the lucigenin- and luminol-based chemiluminescence assays for O2- and H2O2 respectively. Cell lines from CGD patients, with X-linked or autosomal recessive genetic defects in the neutrophil NADPH oxidase, did not respond in these assays, indicative of their inability to produce O2-. The defects in the lines studied encompass both proteins forming the cytochrome b-245 membrane component, and the 47 kDa cytosolic component of the NADPH oxidase. The possession of the disease associated phenotype by these cell lines provides evidence that in the normal situation both neutrophils and B cells produce O2- via the same system.

Acridines↗
PubMed1992

Characterisation by restriction mapping of three subtypes of molluscum contagiosum virus.

DNA from Molluscum contagiosum virus (MCV) isolates was analysed by restriction endonuclease digestion, identifying three virus subtypes. The structural features of MCV DNA are typical of poxviral DNA. Physical maps of cleavage sites for BamHI, CIaI, and HindIII were constructed for single isolates of each subtype. These differ extensively, indicating the independence of the three subtypes. However, they are closely related, as determined by molecular hybridisation and nucleotide sequence analysis, and their genomes are essentially colinear. There is marked geographical variation in the relative incidence of MCV I and II, whilst MCV III is uniformly rare.

Adolescent↗
PubMed1991

Characterization of a molluscum contagiosum virus homolog of the vaccinia virus p37K major envelope antigen.

We present the first nucleotide sequence data for molluscum contagiosum virus (MCV), an unclassified poxvirus. A 2,276-bp XhoI fragment from a near left-terminal fragment of MCV subtype I (MCVI) and a 1,920-bp XhoI fragment from the corresponding locus of MCV subtype II (MCVII) were sequenced and analyzed for open reading frames (ORFs). A large, complete ORF of 1,167 bp was present in both fragments. The putative polypeptide has a calculated molecular mass of 43 kDa (p43K protein) and was shown to have a high degree of homology to the vaccinia virus p37K major envelope antigen (40% amino acid identity and 22% conservative changes). The nucleotide content of the MCV fragments sequenced was 66% G or C. The codon usage within the gene for p43K reflected this high G + C content, with position 3 of codons being predominantly G or C (82 and 87% for MCVI and MCVII, respectively). The MCV p43K-encoding gene has motifs immediately upstream which are similar to those required for vaccinia virus late gene expression. The location and direction of transcription of the MCV p43K-encoding gene were equivalent to those of the vaccinia virus p37K gene, revealing similarity in genetic organization between MCV and vaccinia virus. Another, incomplete ORF was identified downstream of the p43K-encoding gene in both MCVI and MCVII. The sequence immediately upstream of this ORF overlapped the termination codon of the p43K-encoding gene and contained a motif which had homology to the derived consensus sequence for vaccinia virus early gene promoters.

Amino Acid Sequence↗
PubMed1989

Molluscum contagiosum virus types in genital and non-genital lesions.

The endonuclease digest patterns of viral DNA from 48 genital and 45 non-genital molluscum contagiosum virus (MCV) lesions were examined. The overall ratio of MCVI to MCVII was 3.23:1. There was no predominance of either MCV type in genital lesions. No obvious morphological differences were seen between MCVI and MCVII lesions. MCVII was not found in any patient under 15 years old.

Adolescent↗
PubMed1988

BBC microcomputer controlled field inversion gel electrophoresis.

Agarose gel electrophoresis to separate DNA molecules is a widely used technique in molecular biology but there is an upper limit to the sizes that can be resolved. Pulsed field techniques have extended this limit but require expensive equipment. Here we describe a home-made control unit to interface conventional electrophoresis equipment to a BBC microcomputer for the purposes of field inversion gel electrophoresis.

Electrophoresis↗
PubMed1987

Molluscum contagiosum: characterization of viral DNA and clinical features.

Restriction endonuclease analysis of molluscum contagiosum virus DNA revealed two subtypes. In a study of 46 isolates from 41 patients, some with no other disorder and some with atopic dermatitis, the ratio of MCV I isolates to MCV II was 34:12. Multiple clustered lesions removed at the same time from an individual patient yielded only one type of MCV. Lesions induced by MCV I or MCV II were indistinguishable on the basis of size and form. Neither subtype was associated exclusively with lesions at certain sites or with other clinical features. Heterogeneity of DNA restriction endonuclease cleavage patterns amongst isolates of the same subtype was observed, this being greatest for MCV II.

Adolescent↗
PubMed1987

Characterization and physical mapping of Molluscum contagiosum virus DNA and location of a sequence capable of encoding a conserved domain of epidermal growth factor.

DNA from Molluscum contagiosum virus (MCV) isolates was analysed by restriction endonuclease cleavage, revealing two virus subtypes. Physical maps of cleavage sites for BamHI, ClaI and HindIII were constructed, and found to differ extensively between the two subtypes. MCV DNA was similar to Orthopoxvirus DNA with respect to size, terminal cross-linking and the presence of inverted terminal repetitions, but did not hybridize with vaccinia virus DNA. The genomes of the two MCV subtypes cross-hybridized and were colinear except for two small regions. There was sequence homology between DNA from corresponding map regions of the MCV subtypes but, in contrast to Orthopoxvirus DNA, no conservation of restriction sites. A synthetic oligonucleotide probe representing a conserved domain of epidermal growth factor, alpha-transforming growth factor and the vaccinia growth factor identified equivalent regions of both MCV genomes as having the potential to encode this domain. This locus is similar to the position of the vaccinia growth factor gene in vaccinia virus DNA. Thus MCV may induce epidermal cell proliferation and tumourigenesis by expression of an epidermal growth factor-like polypeptide.

Amino Acid Sequence↗