Search PubMed⌕ Search

Biomedical subjects

W F Doe

Publications and source records attributed to W F Doe.

At least 73 records · Page 4Linked to original sources
PubMed1985

Minactivin expression in human monocyte and macrophage populations.

Adherent monolayer cultures of human blood monocytes, peritoneal macrophages, bone marrow macrophages, and colonic mucosa macrophages were examined for their ability to produce and secrete minactivin, a specific inactivator of urokinase-type plasminogen activator. All except colonic mucosa macrophages produced and secreted appreciable amounts of minactivin, but only blood monocytes were stimulated by muramyl dipeptide (adjuvant peptide) to increase production. The minactivin from each of these populations could be shown to preferentially inhibit urokinase-type plasminogen activator and not trypsin, plasmin, or "tissue"-type plasminogen activator (HPA66). A plasminogen-activating enzyme present in monocyte cultures appeared unaffected by the presence of minactivin and could be shown to be regulated independently by dexamethasone.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1985

Lymphokine-activated and natural killer cell activity in human intestinal mucosa.

The activity of natural effector (NE) cells was studied in lamina propria lymphocytes (LPL) obtained from 61 histologically normal specimens of human intestine, which included 45 resected for colon carcinoma and 16 resected for nonmalignant conditions. The mean spontaneous natural killer (NK) cell activity in LPL (1.7 X 10(2) cytotoxic units (C.U.)/10(5) cells) was very low in contrast to that found in peripheral blood mononuclear cells (PBMC) (38.5 X 10(2) C.U./10(5) cells). Significant NK activity was detected in only 16 (47%) of the tissues resected for carcinoma, and in five (38%) of those removed for nonmalignant conditions. Exposure to human leucocyte interferon resulted in only minimal increases in cytotoxicity for K562 target cells. Consistent with these findings, large granular lymphocytes represented less than 0.5% of freshly isolated LPL. Cultures of LPL from both carcinoma and nonmalignant conditions in MLA144-conditioned medium (CM), a source of interleukin 2 (IL 2), generated marked increases in cytotoxicity to levels comparable with or exceeding those found in PBMC. (Mean cytotoxicities were 90.4 X 10(2) and 49 X 10(2) C.U./10(5) cells, respectively.) Cytotoxicity induced by culture in MLA144-CM could be blocked by pretreatment of LPL with the monoclonal antibody anti-Tac directed against the IL 2 receptor. In addition, LPL cultured in recombinant human IL 2 were induced to levels of cytotoxicity that were similar to those induced by MLA144-CM. These data indicate that IL 2 is the factor in MLA144-CM responsible for generating lymphokine-activated killer (LAK) cells in LPL. The IL 2-activated LPL killer cells were OKT11+, OKT3-, Leu-7-, Leu-11b-, as determined by antibody and complement-mediated lysis, and the precursor cells in the lamina propria necessary for generation of killer cells by IL 2 were also OKT11+, OKT3-, Leu-7-, Leu-11b-. These studies indicate that LAK cells may be an important potential source of nonspecific cytotoxicity in the intestinal mucosa.

Carcinoma↗
PubMed1983

Isolation and preliminary characterization of human intestinal macrophages.

Methods for the isolation and culture of macrophages from normal human intestine are described. After disaggregation using sequential treatments of dithiothreitol, ethylenediaminetetraacetate, collagenase, and deoxyribonuclease, Percoll density gradients (1.064 SG) produced single cell suspensions from which macrophages were readily purified by adherence to plastic. Macrophages were characterized by morphology, phagocytosis, cytoplasmic staining for nonspecific esterase, presence of membrane Fc receptors, Ia-like antigens, and lysozyme synthesis and secretion. In 10 separate experiments, recovery of viable mononuclear cells was 2.9 +/- 0.6 x 10(6) cells/g of mucosa. Thirty percent of these cells were phagocytic. After adherence to plastic, the macrophage recovery was 1.05 +/- 0.2 x 10(6) cells/g mucosa and 90% +/- 0.4% of the adherent cells in the monolayer were phagocytic. Fifty-five percent of the adherent cells showed Fc receptors for immunoglobulin G, while 94% expressed the Ia-like antigen on their membrane. The successful isolation and culture of human intestinal macrophages in large numbers will allow detailed study of their role in the mucosal immune response in health and disease.

Cell Survival↗
PubMed1982

Chronic inflammatory bowel disease--increased plasminogen activator secretion by mononuclear phagocytes.

The secretion of the neutral protease plasminogen activator (PA) by cultured macrophages (M phi) was studied in hospitalized patients suffering from chronic inflammatory bowel disease (IBD). There was markedly enhanced secretion of PA by M phi derived from circulating monocytes of the IBD population (18) compared to an age-matched population (16) which was not afflicted by intestinal disease (P less than 0 . 001). Mean M phi PA activity was greater in the population of 11 Crohn's disease patients (P less than 0 . 01) than in a group of seven ulcerative colitis sufferers (P less than 0 . 05) when compared to the control population. While both the treated and untreated hospitalized IBD populations showed increased M phi PA specific activity, results for the nine untreated patients (5 . 56 +/- 1.14 units/micrograms M phi DNA) were substantially higher than those found in the treated IBD population (2 . 91 +/- 0 . 62 units/micrograms M phi DNA) (P less than 0 . 01). These findings reflect the activity of M phi in IBD and suggest a means by which tissue injury is mediated in these conditions.

Adult↗
PubMed1981

Increased circulating T alpha lymphocyte population in bronchogenic and colonic carcinoma.

The proportion of T lymphocytes bearing membrane receptors for IgA (T alpha cells) was markedly increased in the peripheral blood of patients suffering from cancers of the colon and bronchus compared to an age-matched normal population and to age-matched control patients being treated for non-malignant chronic inflammatory conditions of the intestine and lung. By contrast, the percentage of the T lymphocyte population having Fc-IgG receptors (T gamma cells) and Fc-IgM receptors (T mu cells) in mucosal malignancy was similar to that found in the two control populations. It is suggested that the increased percentage of T alpha cells found in colonic and bronchogenic carcinoma patients may reflect an as yet unknown regulatory function for this subset.

Carcinoma, Bronchogenic↗
PubMed1980

Cytotoxic cells induced during lymphocytic choriomeningitis virus infection of mice: natural killer cell activity in cultured spleen leukocytes concomitant with T-cell-dependent immune interferon production.

The characteristics and specificities of spleen and peritoneal cytotoxic cells generated during lymphocytic choriomeningitis virus (LCMV) infection of C3H/St mice were examined. Activated natural killer (NK) cell activity was identified in fresh leukocyte populations from the 2nd to 8th days postinfection, whereas virus-specific cytotoxic T-cell activity was detected from the 6th to 14th days. When leukocytes were cultured overnight at 37 degrees C before assay, T-cell activity was still observed, but nonspecific activated NK cell-like cytotoxicity was only detected on the 6th and to a lesser degree the 8th day postinfection. Overnight culture of leukocytes taken earlier in the infection eliminated their NK cell activity. Similar activities were seen with spleen cell, plastic-adherent peritoneal cell, and nonadherent peritoneal cell populations. The virus-specific cytotoxicity observed with adherent peritoneal cells was due to contamination with cytotoxic T cells, as shown by H-2-restricted cytotoxicity and sensitivity to anti-theta antibody and complement. The nonspecific cultured day 6 effector cell from either the spleen or peritoneum displayed killing specificities and other physical properties identical to those of activated NK cells, but had sensitivities to anti-theta antibody and complement intermediate between activated day 3 NK cells and cytotoxic T cells. Culture stable NK-like cells were not found in athymic nude mice, suggesting a T-cell-dependent mechanism. Whereas LCMV spleen homogenates contained 10-fold-higher levels of interferon at day 2 than at day 6 postinfection, substantially more (nearly 20-fold) interferon was made in cultures of day 6 cells than day 2 cells. Spleen interferon was predominantly type I, whereas the culture interferon was predominantly type II, as shown by acid lability studies. Significant levels of interferon were produced by nylon-wool-passed day 6 spleen cells, and virtually all interferon production was eliminated by treatment of either day 2 or day 6 cells with antibody to theta antigen and complement, suggesting that T cells produced the interferon in vitro. Furthermore, athymic nude mice had no culture-stable NK cells 6 days postinfection, and spleen cells from them failed to produce significant levels of interferon in vitro. Addition of interferon (type I, fibroblast) to cultured C3H spleen cells affect the already elevated levels of cytotoxicity in day 6 cultures, suggesting that the NK cells in the day 6 culture were already activated. Our results suggest that T cells responding to LCMV infection secrete interferon type II which causes the continued activation of NK cells in culture. The resulting population of activated NK cells therefore appears to be relatively stable in culture and to express more theta antigen because of this T-cell dependence. Although one could mistakenly or allospecific cytotoxic T cells or cytotoxic macrophages, more careful examination shows that they are most likely activated NK cells...

Animals↗
PubMed1979

An overview of intestinal immunity and malabsorption.

Intestinal immune responses are adapted to function at external mucosal surfaces. Specialized forms of antibody, secretory immunoglobulin A (IgA) and immunoglobulin M (IgM), provid humoral immunity but little is known of local cell mediated immune reactions. Antigens in the intestinal lumen gain preferential access via Peyer's patches in which sensitised lymphocytes proliferate before entering the lymphatic system. These lymphoblasts return to the intestinal mucosa via the bloodstream to provide predominantly IgA antibody responses. Secretory IgA antibody can neutralize viruses, bacteria and toxins, and appears to block the entry of some food antigens into the lamina propria. Disturbances of intestinal immunity may result in malabsorption. Immunodeficiency states are often associated with malabsorption due to Giardia lamblia infestation. In alpha chain disease there is a malignant expansion of plasma cells in the intestinal mucosa which secrete an abnormal heavy chain fragment of IgA. Arthus type hypersensitivity reactions to milk proteins and gluten may contribute to the mucosal injury in patients suffering from milk allergy and coeliac disease.

Giardiasis↗
PubMed1979

Immunodiagnosis of alpha chain disease.

Since the early diagnosis of alpha chain disease (alphaCD)) is essential to successful treatment and to epidemiological studies, the available immunodiagnostic techniques were compared for their sensitivity, specificity and ease of performance on a panel of sixteen sera, comprising ten alphaCD sera and six control sera containing either IgA myeloma protein or high levels of polyclonal IgA. Immunoselection by immunoelectrophoresis into gel containing a specially developed anti-Fabalpha antiserum provided the most sensitive and specific detection system for alphaCD protein. The same technique using anti-light chain antiserum for immunoselection was also highly sensitive, but proved less specific, being prone to false positives with difficult IgA myeloma proteins. Somewhat less sensitive, but specific and simple to perform, was immunoelectrophoresis using an antiserum recognizing the conformational specificities of Fabalpha as well as those of the constant region of alpha chains. Immunoselection using the Ouchterlony or rocket techniques proved to be less sensitive and prone to false positives when some IgA myeloma sera were tested.

Antibody Specificity↗
PubMed1979

Macrophage stimulation by bacterial lipopolysaccharides. III. Selective unresponsiveness of C3H/HeJ macrophages to the lipid A differentiation signal.

Peritoneal macrophages from the endotoxin-unresponsive C3H/HeJ substrain of mice were entirely refractory to activation in vitro by protein-free LPS, a defect that was not overcome by co-culture of spleen cells from the responder C3H/St substrain with LPS resistant C3H/HeJ macrophages. The defect in responsiveness appears confined to the lipid A activation signal since C3H/HeJ macrophages were fully activated after in vitro treatment by lipid A protein (LAP)--LPS complex, isolated LAP, and BCG. Moreover, after exposure to allogeneic tumor cells in vivo, C3H/HeJ macrophages were cytotoxic for tumor target cells in vitro. By contrast, macrophages from the responder C3H/St strain were fully activated by protein-free LPS to become cytolytic for tumor cells in vitro. C3H/HeJ macrophages, therefore, exhibit a highly selective defect characterized by unresponsiveness to the lipid A activation signal of protein-free LPS and resistance to the toxic effects of high concentrations of LPS that were lethal to the responder C3H/St strain.

Animals↗
PubMed1979

Characterization of an antiserum specific for the Fabalpha fragment. Its use for detection of alpha-heavy chain disease protein by immunoselection.

An antiserum to the Fabalpha fragment of human IgA was prepared by injecting K-and lambda-type IgA1 myeloma protein Fab fragments in complete Freund's adjuvant into a goat. After appropriate absorptions, the antiserum reacted specifically with Fabalpha fragments, normal IgA, and K- and lambda-type IgA1 and IgA2 myeloma proteins. This antiserum contained predominantly antibodies to determinants shared by different IgA myeloma proteins and expressed on isolated alpha chains. These determinants were presumably located on the first constant domain of the alpha chain (Fd fragment). When incorporated into agarose, the anti-Fabalpha antiserum is a potentially valuable reagent for screening human sera for alpha-heavy chain disease proteins by an immunoelectrophoretic method of immunoselection.

Animals↗
PubMed1978

Macrophage stimulation by bacterial lipopolysaccharides. I. Cytolytic effect on tumor target cells.

Bacterial lipopolysaccharides (LPS) stimulate mouse peritoneal macrophages to kill tumor cells in vitro. Lysis is confined to tumor cells where it is nonspecific; both allogeneic and syngeneic cells being susceptible. Stimulation by LPS appears to be due to direct interaction between LPS and macrophages and does not involve participation by lymphocytes. After exposure to LPS, a latent period must elapse before macrophages can lyse tumor cells. The cytolytic mechanism requires contact between target cells and viable effector cells which maintain their lytic capacity for a sustained period and can kill on repeated occasions. The generation of a macrophage cytolytic effect by LPS is critically dependent upon the absolute number of macrophages which must be sufficient to produce confluent monolayers. These findings indicate that LPS stimulation of macrophages in vitro represents a valuable model system for the study of the mechanisms of macrophage stimulation and of the mediation of tumor cell death.

Animals↗