Morphogenetic clonal growth of kidney epithelial cell line MDCK

MDCK (Madin-Darby canine kidney) cells were cultured either dispersed within hydrated collagen gel (HCG) or seeded atop a collagen substrate and then immediately overlaid with HCG. Individual cells exhibited clonal growth in three dimensions to form spherical cysts made up of a simple epithelium enclosing a fluid-filled lumen. The cells of MDCK cysts were polarized with the basolateral surface in contact with the collagen gel and the apical surface bordering the lumen. The ultrastructure of MDCK cysts showed similarities to distal nephron. The cells bore apical microvilli and solitary cilia and had occluding junctions and a simple basolateral surface. MDCK cysts increased in size (greater than 800 microns diameter) with continued culture. MDCK cysts grown between layers of HCG were stripped free of the overlying collagen to give direct access to basolateral surface membrane. Unlike monolayer culture, morphogenetic clonal growth of cell line MDCK produces a polarized cell population with a true lumenal and basolateral surface. Collagen-gel-cultured MDCK cysts provide an easily manipulable in vitro cell system that may offer unique advantages for the study of renal cell structure and function.     

Evaluation of chromosomal diagnosis for hereditary adenomatosis of the colorectum

Hereditary adenomatosis, particularly familial polyposis coli (FPC) and Gardner's syndrome (GS), has been investigated from family pedigrees and chromosomal markers for precancer and cancer. FPC and GS are much alike in phenotypes. Studies are in progress to determine if the two adenomatous diseases are controlled by the same DNA sequence. Chromosome numerical and structural instability is a good diagnostic criterion for hereditary adenomatous diseases where risk factors are already determined to the level of 0.5 probability from pedigree analysis. This has been applied successfully at the pediatric age level to identify family members who carry the gene but have no adenomas in the colorectum. Sister chromatid exchange (SCE) did not distinguish plasma samples from FPC, GS, or solitary adenoma patients form each other or from controls with no adenomas. SCE did distinguish invasive from recurrent and noninvasive cancer. The chromosome #2 polymorphism observed at 2q-21.3 has not been confirmed as a deletion, but is under investigation with more refined methods.     

Human papillomavirus types in anogenital warts of children

Tissue from anogenital warts of 25 children, 10 of whom were suspected of being victims of sexual abuse, was investigated by dot blot and Southern blot techniques for human papillomavirus (HPV) types. HPV DNA was detected in 22 children, two of whom had double infections. The genital HPV types 6 and/or 11 were detected in 20 children, and in three children other HPV types were found. One had HPV 18 (as well as 11); in a second child a possible skin type, HPV 2, was detected; and the third child was infected with an unidentified type. In three cases genital wart material was available from one of the parents, and in all three the HPV type was the same as that of the child. For nine other children one or both parents were reported to have genital warts. The source of infection appeared to be the adult genital tract, but sexual contact might not be the only means of transmission.     

The kinetics of specific immune responses in rhesus monkeys inoculated with live recombinant BCG expressing SIV Gag, Pol, Env, and Nef proteins

Development of an effective preventive or therapeutic vaccine against HIV-1 is an important goal in the fight against AIDS. Effective virus clearance and inhibition of spread to target organs depends principally on the cellular immune response. Therefore, a vaccine against HIV-1 should elicit virus-specific cytotoxic lymphocyte (CTL) responses to eliminate the virus during the cell-associated stages of its life cycle. The vaccine should also be capable of inducing immunity at the mucosal surfaces, the primary route of transmission. Recombinant Bacille Calmette-Guérin (BCG) expressing viral proteins offers an excellent candidate vaccine in view of its safety and ability to persist intracellularly, resulting in the induction of long-lasting immunity and stimulation of the cellular immune response. BCG can be administered orally to induce HIV-specific immunity at the mucosal surfaces. The immunogenicity of four recombinant BCG constructs expressing simian immunodeficiency virus (SIV) Gag, Pol, Env, and Nef proteins was tested in rhesus macaques. A single simultaneous inoculation of all four recombinants elicited SIV-specific IgA and IgG antibody, and cellular immune responses, including CTL and helper T cell proliferation. Our results demonstrate that BCG recombinant vectors can induce concomitant humoral and cellular immune responses to the major proteins of SIV.     

Evaluation of Streptococcus pneumoniae Type XIV Opsonins by Phagocytosis-Associated Chemiluminescence and a Bactericidal Assay

The relative roles of serum factors required for opsonization of type XIV Streptococcus pneumoniae were investigated by means of luminol-enhanced chemiluminescence (CL), bactericidal, and immunofluorescence assays employing adult sera containing high (>1,000 ng of antibody nitrogen per ml) or low (<200 ng of antibody nitrogen per ml) antibody concentrations as determined by radioimmunoassay. Specific antibody concentration correlated directly with both total and heat-labile CL activity (P < 0.005) and with the bactericidal index (P < 0.05) at a serum concentration of 10%. The importance of specific antibody as an opsonin was confirmed by the abolition of CL activity and immunoglobulin immunofluorescence observed after absorption of heated sera with type XIV pneumococcal cells and by the dose response in CL and bactericidal activity observed with the addition of immunoglobulin G to hypogammaglobulinemic serum. A role for the classical complement pathway in opsonization was indicated by significantly greater CL integrals for high-antibody sera than for low-antibody sera depleted of factor D and by the bactericidal activity noted for untreated, but not magnesium ethylene glycol-bis(β-aminoethyl ether)-N,N-tetraacetic acid-chelated low-antibody sera. The alternative pathway contributed more than half of the CL activity of both high- and low-antibody sera. However, after magnesium ethylene glycol-bis(β-aminoethyl ether)-N,N-tetraacetic acid chelation, only sera with high antibody concentrations or agammaglobulinemic serum reconstituted with immunoglobulin G with high specific antibody levels supported significant bactericidal activity. Therefore, type-specific antibody and complement promote opsonization of type XIV S. pneumoniae, and this may occur via either complement pathway. These results suggest that CL is a suitable tool to delineate serum factors and their contribution to opsonization, but results must be related to other functional assays.     

High-level expression of EphA2 receptor tyrosine kinase in prostatic intraepithelial neoplasia

EphA2 is a transmembrane receptor tyrosine kinase that is overexpressed in many carcinomas. Specific targeting of EphA2 with monoclonal antibodies is sufficient to inhibit the growth, migration and invasiveness of aggressive cancers in animal models. Using immunohistochemical analyses, we measured the expression of EphA2 in prostatic adenocarcinoma, high-grade prostatic intraepithelial neoplasia, and adjacent benign prostate tissue from ninety-three radical prostatectomy specimens. These results were related to multiple clinical and pathologicalcharacteristics. The fraction of cells staining positively with EphA2 in benign prostatic epithelium (mean, 12%) was significantly lower than that in high-grade prostatic intraepithelial neoplasia (mean, 67%, P < 0.001) and prostatic adenocarcinoma (mean, 85%, P < 0.001). Moreover, the intensity of EphA2 immunoreactivity in prostatic adenocarcinoma was significantly higher than in benign prostatic tissue (P < 0.001) or high-grade prostatic intraepithelial neoplasia (P < 0.001). Benign prostatic epithelium showed weak or no immunoreactivity for EphA2 in all cases examined. Whereas EphA2 immunoreactivity related to neoplastic transformation, it did not correlate with other clinical and pathological parameters examined. Our data suggest that EphA2 levels increase as prostatic epithelial cells progress toward a more aggressive phenotype. Progressively higher levels of EphA2 in high-grade prostatic intraepithelial neoplasia and prostatic carcinoma are consistent with recent evidence that EphA2 functions as a powerful oncogene. Moreover, the presence of high levels of EphA2 in these cells suggests opportunities for prostate cancer prevention and treatment.