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H L Mathews

Publications and source records attributed to H L Mathews.

At least 37 records · Page 2Linked to original sources
PubMed1993

A quantitative radiometric assay to measure mammalian cell binding to hyphae of Candida albicans.

A rapid and reproducible assay has been developed to measure the capacity of lymphocytes to bind to Candida albicans. Lymphocytes that bound to C. albicans were either the large granular lymphocyte cell line, YT, or interleukin-2 activated lymphocytes. Lymphocyte binding was assessed as the associated radioactivity of 51Cr-labeled lymphocytes with preformed hyphae. The assay was sensitive to detection of 0.6 lymphocytes/one hyphal form at one half maximal lymphocyte binding capacity. The assay correlated well with direct microscopic assessment of lymphocyte binding to C. albicans and provided quantitative radiometric data. Although the assay was developed for the assessment of lymphocyte adhesion to C. albicans, it can be used to measure binding of other mammalian cells (e.g., polymorphonuclear leukocytes) to this fungus. In addition, the assay may be used to identify molecules involved in the adhesion of lymphocytes and other mammalian cells to C. albicans.

Animals↗
PubMed1993

Quantitative measurement of lymphocyte mediated growth inhibition of Candida albicans.

A rapid and reproducible assay has been developed to measure the capacity of lymphocytes to inhibit the growth of Candida albicans. Fungal growth inhibition was assessed optimally as the incorporation of [3H]uridine into preformed hyphae, following interaction of the hyphae with effector lymphocytes. The assay was sensitive to the detection of fungal growth inhibition by lymphocytes at low effector to target ratios and results correlated well with other methods for measurement of anti-C. albicans growth inhibition in vitro. Although the assay was developed for the measurement of lymphocyte mediated anti-fungal activity, other mammalian cell populations can be assayed for growth inhibition of C. albicans as well. The described assay utilizes the enzyme lyticase to reduce the surface binding of C. albicans. The use of this enzyme permits the efficient harvest of large numbers of experimental samples with a multiple automated sample harvester.

Animals↗
PubMed1993

Immune cells mediate epinephrine secretion from bovine chromaffin cells in vitro.

Potential immunological influences on peripheral catecholamine secretion were investigated by measuring epinephrine secretion from chromaffin cells in vitro in response to cell-free conditioned media from mononuclear cells. Chromaffin cells were isolated from bovine adrenals whereas mononuclear cells were isolated from bovine spleen tissue or whole bovine blood. In secretion experiments epinephrine release and epinephrine remaining in cells was determined such that secretion was expressed as % of total cell content. After 90 minutes exposure to conditioned media, 22.8 +/- 1.1% of content was released compared to 1.7 +/- 0.2% with RPMI media. Secretion after filtration (< 3,000 MW cutoff) was 21.6 +/- 0.9% whereas after boiling and boiling in acid, secretion was 10.2 +/- 0.2 and 4.3 +/- 0.1% respectively. Dialysis (< 3,000 MW cutoff) reduced the 90 min conditioned media-stimulated epinephrine secretion from 22.5 +/- 3.8% to 2.3 +/- 0.3%. Neither atropine nor hexamethonium blockade altered the conditioned media-stimulated epinephrine secretion. These results suggest that mononuclear cells produce a low molecular weight substance--most likely a peptide--that contributes to the stimulation of epinephrine secretion.

Adrenal Glands↗
PubMed1993

Macrophage treatment in suckling rat endotoxic shock.

Gram-negative sepsis/septic shock in the human newborn continues to be a severe medical problem because of significant mortality and morbidity. Since macrophages detoxify endotoxin, a decreased number of macrophages may contribute to the newborn's sensitivity to endotoxin. In this study, peritoneal macrophages were used for the treatment of endotoxic shock in 10-day-old rats, and 24-hr mortality, plasma glucose, and lactate concentrations were monitored. Peritoneal macrophages were harvested from adult or 10-day-old rats. Caseinate-stimulated macrophages from adult and 10-day-old rats significantly decreased the mortality of 10-day-old rat endotoxic shock from 90% to 37.5% and 44.4%, respectively. Resident macrophages from adult and 10-day-old rats also decreased the mortality from 90% to 12.5% and 45.4%, respectively. Peritoneal macrophages from adult rats significantly ameliorated hypoglycemia during endotoxic shock in a dose-dependent manner. Macrophage treatment decreased plasma endotoxin concentration (P < 0.05). Macrophage treatment was important for host defense.

Animals↗
PubMed1992

Systemic IL-1 and adjuvant treatment of an experimental tumor. I. Immune status following tumor rechallenge.

Local adjuvant therapy of weakly immunogenic tumors protects against primary tumor challenge. However, this form of therapy does not produce long-lasting immunity to the tumor. In this study, local adjuvant therapy combined with systemic IL-1 administration produced not only primary tumor protection, but also long lasting immunity to the tumor. IL-1 and adjuvant protected animals resisted rechallenge with tumor as much as 180 days after initial tumor administration. Resistance to tumor rechallenge was IL-1 dose dependent. IL-1 and adjuvant protected animals also exhibited delayed type hypersensitivity reactions which were tumor-specific. Splenic and lymph node cell populations from IL-1 and adjuvant protected animals mounted tumor-specific lymphoproliferative responses. No such responses were observed in animals which had been administered either IL-1 or adjuvant alone. These results demonstrate that systemic IL-1 functions to augment specific immune protection when administered in conjunction with local adjuvant, resulting in long-lasting tumor immunity.

Animals↗
PubMed1992

Systemic IL-1 and adjuvant treatment of an experimental tumor. II. Immune status during primary tumor challenge.

In this investigation, systemic administration of interleukin-1 (IL-1) and local adjuvant therapy were shown to modify immunological parameters associated with the lymphatics draining the site of experimental tumor inoculation. These immunological parameters were shown to be modified early (within 7 days) following tumor inoculation and within the time period of IL-1 administration. IL-1 induced a marked increase in the number of lymphocytes within the brachial and axillary lymph nodes associated with the tumor inoculation site. This increase was characterized by an overall augmentation in the number of CD8+ and CD4+ lymphocytes. In vitro, these lymph node cells showed enhanced proliferation in response to interleukin-2 (IL-2) when compared to non-IL-1 treated animals, and were capable of mounting a potentially greater cytotoxic response for both NK sensitive and NK resistant tumor targets. Without IL-1 administration, temporal and sequential lymph node cellular changes were observed, but were diminished and delayed when compared to the IL-1 treated animals. By adoptive transfer of tumor resistance, lymph node cells from IL-1 treated animals were demonstrated to be tumor-protective in vivo. These results demonstrate that systemic IL-1 induces regional changes in the lymphatics of mice undergoing primary tumor challenge with adjuvant therapy and that these changes result in tumor protection for the host.

Adjuvants, Immunologic↗
PubMed1992

Growth inhibition of Candida albicans by interleukin-2-activated splenocytes.

Murine splenocytes, Percoll-enriched low-density lymphocytes, and interleukin-2 (IL-2)-activated lymphocytes were assessed for the capacity to limit the growth of the hyphal form of Candida albicans. No fungal-growth-inhibitory activity was exhibited for C. albicans by either splenocytes or Percoll-enriched lymphocytes. These cells were capable of cytotoxic activity for a natural killer cell-sensitive cell line. However, when cultured for several days with IL-2, splenocytes acquired the capacity to inhibit the growth of the fungus. The appearance of the antifungal activity coincided with the development of cytotoxic activity for the natural killer cell-insensitive cell line. Anti-C. albicans and antitumor activities of IL-2-activated lymphocytes were competitively and reciprocally inhibited by C. albicans and the natural killer cell-sensitive and -insensitive cell lines. The antifungal activity of the IL-2-activated lymphocytes was exhibited against a number of clinical isolates of C. albicans and related fungal species. IL-2-activated human peripheral blood lymphocytes also acquired the capacity to inhibit the growth of C. albicans. These data show that in vitro growth inhibition can be mediated by IL-2-stimulated lymphocytes which are neither fungal strain nor mammalian species restricted in their biological activity.

Animals↗
PubMed1990

Growth inhibition of Candida albicans by interleukin-2-induced lymph node cells.

Previous reports have demonstrated natural killer cells (NK) to exert growth inhibitory effects against certain fungi, but not against Candida albicans. In this investigation, interleukin-2 (IL-2)-induced lymph node cells with phenotypic and functional characteristics of NK were shown to inhibit the growth of C. albicans. Growth inhibition was evaluated by both the release of 51Cr by the fungus and the inhibition of microcolony growth of the fungus on Sabouraud's dextrose agar. Lymphoid cells derived from C57Bl/6 mice and immediately assessed for hyphal growth inhibition showed little or no activity. However, significant hyphal growth inhibition was produced by lymph node cells cultured with recombinant IL-2. Growth inhibitory activity was dependent upon the concentration of IL-2 and was mediated by nonadherent lymphocytes which lysed an NK-susceptible and to a lesser extent an NK-resistant cell line. Treatment of the IL-2-induced cells with anti-asialo GM1 but not anti-Thy-1 and complement abrogated growth inhibition of C. albicans. These results suggest that IL-2-induced lymph node cells with functional and phenotypic characteristics similar to those of activated NK, mediate in vitro growth inhibition of the hyphal form of C. albicans.

Animals↗
PubMed1983

A solid-phase radioimmunoassay to detect antibodies produced by hybridomas to antigens derived from human melanoma cells.

A solid-phase radioimmunoassay to detect antibodies that react with antigens derived from human melanoma cells is described. A soluble preparation derived from Nonidet P-40 lysates of tissue-cultured melanoma cells was dried on the surfaces of wells of polyvinyl chloride microtiter plates and fixed with 0.02% glutaraldehyde. Antibody preparations were added and incubated for 18 h at 4 degrees C. The wells were washed and bound antibodies were detected using radioactive Staphyloccoccal protein A (125I-SpA). Optimal conditions are described for all the steps employed. Concentrations of antigen selected, the amount of 125I-SpA employed and the duration of incubation of antibodies with antigen were found to be critical. The assay was sensitive and reproducible, and lent itself to the simultaneous evaluation of many individual antibody samples in a short period of time. The assay was particularly valuable for rapid screening of hybridoma supernatants for antibodies to antigens derived from melanoma cells and from a panel of other tumor and normal cells.

Animals↗
PubMed1983

The use of cellular immunoadsorbents to prepare polyclonal antibodies that distinguish between antigens derived from human melanoma cells and autologous lymphocytes.

Cellular immunoadsorbents were employed to isolate xenogeneic antibodies that reacted with a restricted group of antigens on human melanoma cells. Melanoma cells and autologous lymphoid cells were grown in tissue culture. Cellular immunoadsorbents were prepared by coupling formalin-treated melanoma and lymphoid cells to diethylaminoethyl cellulose. Rabbits were immunized with melanoma cells and antisera were passed sequentially through immunoadsorbents made of fetal bovine serum, and lymphoid cells. Unbound effluents were then passed through an immunoadsorbent prepared with melanoma cells. Antibodies binding to melanoma cells were eluted and their reactivity to melanoma-derived antigens was tested using a solid-phase radioimmunoassay. Antigens for this assay were NP-40 lysates of melanoma and lymphoid cells and fetal bovine serum. Radioactive Staphylococcal protein A was used to detect binding by the antibodies to the test antigens. The effects of formalin-fixation and storage of melanoma and lymphoid cells were studied. Storage of fixed melanoma cells for periods up to 4 months did not affect their capacity to bind antibodies. A single exposure of formalin-fixed cells to a low-pH elution buffer which was followed by neutralization did not affect binding by these cells. Antibodies isolated in this manner were of the IgG class and reacted with antigens derived from melanoma cells but not from autologous lymphocytes or fetal bovine serum. This study demonstrated the feasibility of using cellular immunoadsorbents to prepare xenogeneic polyclonal antibodies with a high degree of reactivity to antigens derived from human melanoma cells.

Animals↗
PubMed1980

Suppression and immunotherapy of the guinea pig line 10 hepatocarcinoma mediated by heat-killed disrupted Mycobacterium bovis strain Bacillus Calmette-Guérin.

Heat-killed Mycobacterium bovis strain Bacillus Calmette-Guérin cells were sonically disrupted, and their antitumor effects against the line 10 hepatocarcinoma in strain 2 guinea pigs were evaluated. When injected together with viable line 10 cells, there was complete suppression of tumor growth. Growth of tumor was also suppressed when line 10 cells were injected contralaterally at the same time as the vaccine mixture. Multiple intratumor injections of sufficient disrupted M. bovis strain B. Calmette-Guérin were therapeutically effective against 74% of 7-day-old tumors and against 40% of 14-day-old tumors. Surviving animals were usually resistant to subsequent rechallenges with line 10 cells but not to syngeneic L2C leukemia cells. By means of a competitive radioimmunoassay, antigenic determinants were detected that were expressed by disrupted but not by intact bacteria.

Animals↗
PubMed1980

Immunotherapy of the guinea pig line 10 hepatocarcinoma with a variety of nonviable bacteria.

A variety of heat-killed bacteria were tested for their capacity to induce regressions of established line 10 hepatocarcinomas in syngeneic guinea pigs. Multiple intralesional injections of heat-killed Escherichia coli, Streptococcus mutans, Listeria monocytogenes, and Propionibacterium acnes resulted in complete regression of the tumor in a majority of guinea pigs. Repeated injections of heat-killed Mycobacterium bovis strain Bacillus Calmette-Guérin caused no regressions. Surviving animals were immune to subsequent challenge with line 10 cells but not L2C cells, another syngeneic tumor.

Animals↗
PubMed1980

The use of cellular immunoadsorbents to prepare antibody that distinguishes between syngeneic surface antigens on two guinea pig hepatocarcinomas.

Xenogenic antibodies with reactivity for surface determinants of the guinea pig line-10 hepatocarcinoma were isolated by using cellular immunoadsorbents prepared by coupling formalin-treated line-10 cells to diethylaminoethyl cellulose. Antibodies prepared in this manner exhibited a high degree of reactivity for line-10 surface determinants. These antibodies also reacted with surface determinants of the syngeneic line-1 hepatocarcinoma. Further specificity of antibody reactivity to the line-10 hepatocarcinoma was accomplished by passage of the antibodies through cellular immunoadsorbents prepared with syngeneic line-1 hepatocarcinoma cells. By direct binding studies, these antibodies showed significantly reduced reactivity for line-1 cells and no reactivity for guinea pig spleen cells or for the unrelated murine EL-4 lymphoma. By a competitive radioimmunoassay, these antibodies reacted only with determinants expressed on the surfaces of line-10 cells and not on syngeneic line-1, L2C, spleen, thymus; or xenogeneic EL-4 cell surfaces. In a similar manner, line-10-associated antigens were detected in ascites fluid derived from line-10 tumor-bearing animals. The sequential use of immunoadsorbents made of antigenically distinct but syngeneic tumor cells made it possible to prepare antibodies with restricted reactivity for line-10-associated antigens and should be applicable to the isolation of "tumor-specific" antibodies in other systems.

Animals↗
PubMed1979

Purification of antibodies to bacterial antigens by an immunoadsorbent and a method to quantify their reaction with insoluble bacterial targets.

A combination of procedures was employed to develop a radioimmunoassay which quantified the binding of antibodies to antigens of either intact Propionibacterium acnes or to antigens of insoluble extracts derived from the bacteria. Reactive antibody populations were purified by use of bacterial immunoadsorbents which were prepared by coupling P. acnes to diethylaminoethyl cellulose. Binding of antibodies was detected with [125I]staphylococcal protein A ([125I]SpA) and optimal conditions for the assay defined by varying the amounts of antibodies, bacterial antigenic targets and [125I]SpA. In antibody excess, 100% of available [125I]SpA was bound by the target-antibody complexes. However, when antibody concentration was limiting, a linear relationship was demonstrated between per cent specific binding of [125I]SpA and antibodies bound to bacterial targets. These results were achieved only with immunoadsorbent-purified antibody populations and not with hyperimmune sera or IgG. The radioimmunoassay detected subtle antigenic differences and similarities between P. acnes, P. acnes extracts and a variety of unrelated microorganisms.

Animals↗
PubMed1976

Single-tube mixed agglutination test for the detection of staphylococcal protein A.

A simple, rapid mixed agglutination test using sheep erythrocytes (SRBC) sensitized with rabbit hemolysin and intact viable staphylococci is described for the detection of bound staphylococcal protein A. Soluble protein A was heat extracted from 50 clinical isolates as well as the Cowan I and Wood 46 strains of Staphylococcus aureus and titered by a hemagglutination test using sensitized SRBC and dilutions of soluble protein A. Protein A could be detected in all of these supernatants including that of S. aureus Wood 46, a strain generally considered to be protein A negative. These organisms were later retested by the mixed agglutination test and even those staphylococcal isolates expressing very low heat-extractable soluble protein A concentrations (1:2 titers) were positive, confirming the sensitivity of the test. In a screen of clinical isolates, only 4 of 235 (1.8%) coagulase-positive isolates were negative in the mixed agglutination test. Of 25 coagulase-negative isolates, none yielded a positive reaction.

Agglutination Tests↗