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Biomedical subjects

C W Reynolds

Publications and source records attributed to C W Reynolds.

At least 55 records · Page 3Linked to original sources
PubMed1987

Nickel--magnesium interactions in carcinogenesis: dose effects and involvement of natural killer cells.

The effects of magnesium carbonate (MgCarb) on carcinogenesis and natural killer (NK) cell modulation by nickel subsulfide (Ni3S2) were studied. Male Fischer F344/NCr rats, 50-90 g body wt, 20 rats per group, received single i.m. injections into both thigh muscles of 2.5 mg Ni3S2 alone or combined with different proportions of MgCarb; the Mg/Ni molar ratio ranged from 0.25 to 4.0. Control rats received i.m. injections of normal saline or magnesium acetate (MgAcet), or s.c. MgCarb at a site distant from Ni3S2. The animals were observed over 79 weeks for the development of tumors. The NK cell activity was determined over the first 3 weeks of the experiment in separate groups of rats treated as above, with the use of the 51Cr/YAC-1 release assay for blood and spleen cells and the peroxidase localization of Ox-8-immunoreactive lymphocytes at the injection site. I.m. administration of MgCarb mixed with Ni3S2 up to the Mg/Ni molar ratio of 1.0 inhibited the carcinogenicity of Ni3S2 in a dose-related manner; final incidence of sarcomas decreased from 100 to 55% and the appearance of first tumors was delayed from 25 to 39 weeks. Higher doses of MgCarb did not exert further effect. Distant s.c. injection of MgCarb or local i.m. application of MgAcet did not change the carcinogenic potency of i.m. Ni3S2. MgCarb or saline alone did not produce any tumors. I.m. Ni3S2 had no significant influence on the activity of NK cells in blood and spleen, while i.m. MgCarb alone did not affect the NK activity in blood but doubled it transiently in the spleen 24 h after injection. In the injected muscle, Ox-8-positive cells became abundant around MgCarb but could not be found close to Ni3S2. This inhibitory effect of Ni3S2 was partially reversed by MgCarb. Also, numerous multinucleated giant cells infiltrated the sites of injection of MgCarb alone and MgCarb + Ni3S2 but not Ni3S2 alone. The results indicate a dose-dependent and strictly local character of the inhibition by MgCarb of Ni3S2 carcinogenesis, as well as a possible involvement of NK and phagocytic cells in this inhibition.

Animals↗
PubMed1987

Antitumor activity of a Streptococcus pyogenes preparation (OK-432). I. Sequential effector mechanisms following a single OK-432 injection in F344 rats leading to the rejection of syngeneic MADB106 tumor cells.

The effector mechanisms evoked in tumor-bearing rats following a single injection of the avirulent Su strain of type 3, group A Streptococcus pyogenes (OK-432) were sequentially examined. F344 rats challenged ip with a lethal dose of the syngeneic MADB106 mammary carcinoma could survive more than 100 days when given 50 mg OK-432/kg ip 1 day after tumor challenge. When the responsible effector mechanisms were examined in this therapeutic model, two distinct effector phases distinguished by the number of tumor cells were evident. Phase I, 1-6 days following OK-432 injection, resulted in a sharp decrease in tumor cell numbers and was related to the direct antitumor cytotoxicity of OK-432 and was coincident with an increase in the number of polymorphonuclear neutrophils. However, by day 6 a sharp increase in tumor cell numbers was again observed. Subsequently, a second phase of tumor cell destruction was observed 7-20 days following OK-432 injection and was reflected in a strong lymphocyte-mediated cytotoxicity response as well as the production of complement-dependent cytotoxic antibody against the MADB106 tumor cells. Further, the adoptive transfer of either peritoneal exudate cells or sera from the phase II animals revealed that both factors may be responsible for the antitumor activity observed in this therapeutic model. In conclusion, this study has demonstrated that the antitumor effects seen with OK-432 are due to a combination of sequential effector mechanisms leading to the eventual rejection of established tumor.

Animals↗
PubMed1987

Antitumor activity of a Streptococcus pyogenes preparation (OK-432). II. Analysis of the cytotoxic lymphocytes induced by OK-432 injection into tumor-bearing F344 rats.

In the present study, the antigenic phenotype and target cell specificity of the cytotoxic lymphocytes observed in F344 rats following the ip inoculation of a syngeneic MADB106 mammary carcinoma and the single injection of OK-432 were examined. When the cytotoxicity of peritoneal exudate cells (PECs) was measured in a 4-hour 51Cr release assay, appreciable cytotoxicity against MADB106 tumor cells was evident by day 7-14 following OK-432 injection. With the use of an antibody (R1-3B3) and complement depletion of cytotoxic PECs, the MADB106 killer cells appeared to consist of both R1-3B3- (non-T) and R1-3B3+ (T) cells, with most of the anti-MADB106 killing residing in the R1-3B3- cell population. The R1-3B3- killer cells were further defined as: a) phenotypically asialoGM1+, b) present in athymic nude rats, and c) accompanied by some augmentation of YAC-1 killing [the prototype rat natural killer (NK) target], suggesting that some of these R1-3B3- killer cells were typical NK cells. However, it was also observed that most of the R1-3B3- cells that killed MADB106 tumor cells were: 1) phenotypically or functionally different from either cytotoxic T-cells or typical NK cells; 2) observed only in MADB106 tumor-bearing rats challenged with OK-432; 3) not present on day 1-2 following OK-432 injection, the time when YAC-1 killing was maximally augmented; and 4) present in high numbers in a secondary response following reinoculation of the MADB106 tumor cells into cured rats. The in vivo relevance and possible derivation of these various cytotoxic lymphocyte populations in the syngeneic tumor-bearing hosts are discussed.

Animals↗
PubMed1986

Natural killer cell activity in the rat. V. The circulation patterns and tissue localization of peripheral blood large granular lymphocytes (LGL).

Large granular lymphocytes (LGL) and T cells were separated from blood by centrifugation on discontinuous gradients of Percoll, were labeled with [3H]uridine or [111In]oxine, and were injected i.v. into syngeneic euthymic or athymic nude rats. The tissue distribution of these labeled cells was monitored for up to 24 hr after transfer by scintillation counting of tissue homogenates and autoradiography of tissue sections. In normal euthymic rats, the main sites of LGL localization were the alveolar walls of the lungs and spleen red pulp; however, they were not detectable in the major traffic areas of T lymphocyte recirculation, the spleen white pulp, and lymph nodes. Furthermore, the density of labeled LGL was very low in the small intestine, thymus, kidney, and liver, although on a per-organ basis, about 10% of the injected radioactivity was found in the liver by 24 hr post-injection. When 111In-labeled LGL were injected i.v. into rats with an indwelling thoracic duct cannula, they completely failed to enter the thoracic duct lymphocyte (TDL) population over an observation period of 6 days. This finding was markedly different from the results obtained with T cells and was consistent with the lack of natural killer and antibody-dependent cellular cytotoxicity activity observed among TDL, even in rats pretreated with the biological response modifier, poly I:C. LGL in athymic nude rats also failed to recirculate between blood and lymph. However, in contrast to normal euthymic animals, a significant increase in the localization of radiolabeled LGL to lymph nodes was observed in nude rats between 30 min and 24 hr. Taken as a whole, these findings define the areas within the lungs and spleen in which blood LGL normally localize, and clearly demonstrate that LGL do not normally recirculate between blood and lymph.

Animals↗
PubMed1986

Analysis of T cell receptors in highly purified rat and human large granular lymphocytes (LGL): lack of functional 1.3 kb beta-chain mRNA.

Recent reports have suggested that the T cell receptor for antigen is somehow involved in the cytotoxicity of natural killer (NK) cells. However, we now report that highly purified, freshly isolated large granular lymphocytes (LGL) from both the human and rat, as well as LGL cultured in the presence of recombinant IL 2, express only the 1.0 kb beta-chain mRNA. The lack of a 1.3 kb mRNA, indicative of a functional beta-chain rearrangement, strongly suggests that a functional T cell receptor beta-chain is absent in freshly isolated LGL, thus making it extremely unlikely that this molecule is involved in target cell recognition by NK cells. These results also suggest that LGL are derived from a lineage distinct from T cells or develop before a functional rearrangement of the T cell receptor beta-chain.

Animals↗
PubMed1985

Lack of gene rearrangement and mRNA expression of the beta chain of the T cell receptor in spontaneous rat large granular lymphocyte leukemia lines.

Using the murine cDNA clone for the beta chain of the T cell antigen receptor, we have examined four highly cytotoxic rat large granular lymphocyte (LGL) leukemia lines for the expression of unique rearrangements and mRNA transcription of the genes coding for the T cell antigen receptor. In contrast to normal rat T cells and nine rat T cell lines, the LGL leukemia lines exhibited no detectable gene rearrangements in the beta chain locus after digestion of LGL DNA by four restriction enzymes. Northern blots containing RNA from these LGL tumor lines demonstrated a low level of aberrant or nonrearranged beta chain transcription (less than 10 copies per cell) but virtually no translatable 1.3 kilobase message. These results demonstrate that LGL leukemia lines which mediate both natural killer (NK) and antibody-dependent cell-mediated cytotoxicity (ADCC) activities do not express the beta chain of the T cell receptor. The nature of the NK cell receptor for antigen remains elusive.

Animals↗
PubMed1985

Large granular lymphocyte (LGL) lymphoproliferative diseases: naturally cytotoxic tumors in man and experimental animals.

It has recently become clear that in the spleen and blood of both rodents and man that a unique subpopulation of lymphocyte is the mediator of virtually all of the inherent natural killer (NK) and antibody-dependent cell-mediated cytotoxic (ADCC) activity. Because of their large size, eccentric kidney-shaped nucleus and prominent cytoplasmic granules, these cytotoxic cells, termed large granular lymphocytes (LGL), can be readily identified in Geimsa stained cytocentrafuge preparations. Unfortunately, the relatively low numbers of these cells in normal lymphoid tissues has made the detailed analysis of LGL quite difficult. Recently however, a number of investigators have reported both rodent and human leukemias or leukocytosis in which there was an abnormally high number of circulating lymphocytes with either the appearance and/or function of LGL. The present manuscript reviews this literature with an emphasis on the biological and clinical characteristics of this lymphoproliferative disease. Emphasis is also placed on the usefulness of these cells for the detailed analysis of LGL morphology and function.

Acute Disease↗
PubMed1985

Direct evidence for the role of LGL in the inhibition of experimental tumor metastases.

The role of NK cells in the control of the metastatic spread of tumor cells was studied. Rats pretreated with rabbit anti-asialo GM1 (anti-asGM1) serum exhibited a diminished ability to destroy circulating MADB106 mammary adenocarcinoma cells, which in turn caused an increased incidence of experimental pulmonary metastasis. The anti-asGM1 treatment caused a selective inhibition of NK activity without detectable effect on T cell-mediated immunity, and overall had no effect on the cytotoxic activity or numbers of alveolar macrophages (alv.M phi) or monocytes. The suggestion of a role for NK cells in resistance to metastases from the MADB106 tumor cells was confirmed by the adoptive transfer of 5 X 10(6) highly purified large granular lymphocytes (LGL) into NK-depressed animals 2 hr before tumor challenge. This transfer of LGL, highly enriched in NK activity, partially or fully restored the ability of these rats to inhibit the development of pulmonary metastases. This ability to adoptively transfer resistance to metastases appeared to be confined to the LGL population, because transfer of the same number of mature peripheral blood T cells had no effect on tumor development. These results provide the first unequivocal evidence that LGL, with high NK activity, are involved in in vivo resistance to tumors, particularly in the elimination of potentially metastatic tumor cells from the circulation and capillary beds.

Adenocarcinoma↗
PubMed1984

Augmentation of organ-associated natural killer activity by biological response modifiers. Isolation and characterization of large granular lymphocytes from the liver.

Natural killer (NK) activity in the rat and human has been attributed to cells having the morphology of large granular lymphocytes (LGL). However, this association has been less clear in the mouse, largely because of difficulties in obtaining highly enriched populations of LGL from normal spleen and blood. We have previously observed that the administration of the biological response modifier (BRM) maleic anhydride divinyl ether (MVE-2) strongly augmented NK activity in lung and liver, and the augmented NK activity coincided with increased resistance to the formation of experimental metastases in these organs. The degree of NK augmentation was most striking in the liver, an unexpected and previously unreported observation. In the present study, both MVE-2 or Corynebacterium parvum induced a dramatic augmentation of liver NK activity, which reached maximum levels 3-5 d after treatment. This augmentation of NK activity in the liver coincided with a large increase in the number of lymphoid cells with the morphological characteristics of LGL that could be isolated from enzymatically digested suspensions of perfused liver. The yield of LGL per liver following BRM treatment corresponded to a 10-50-fold increase as compared to normal mice. LGL were purified from these enzymatically digested suspensions of perfused liver by depletion of adherent cells on nylon wool columns and subsequent enrichment for low-density lymphoid cells by fractionation on Percoll density gradients. The enrichment of LGL correlated with greatly increased NK activity against YAC-1. Conversely, the higher-density fractions were depleted of both LGL and NK activity. This increase in NK activity in the liver was suppressed by in vivo treatment with anti-asialo GM1 (asGM1) serum. This treatment also resulted in a corresponding reduction in both the total number and percentage of LGL. By flow cytometry analysis, the phenotype of the majority of these highly cytolytic LGL isolated from the livers of BRM-treated mice were asGM1+, Thy-1+, Ly-5+, Qa-5+, Mac-1+, and Gma-1+, whereas these LGL were Ly-1-, Lyt-2-, L3T4-, and surface Ig-. We conclude that the livers of BRM-treated mice can provide a rich source of highly active mouse LGL that could be used for further characterization of this lymphocyte subset. Further, these studies imply a potential for BRM therapy of neoplastic or viral diseases through augmentation of organ-associated immune responses.

Adjuvants, Immunologic↗
PubMed1984

Cytolytic activity of purified cytoplasmic granules from cytotoxic rat large granular lymphocyte tumors.

Purified cytoplasmic granules from cytotoxic rat large granular lymphocytes (LGL) tumors were cytolytic to erythrocytes, splenocytes, and a number of different lymphoid tumor cells. Granule concentrations of approximately 1 microgram/ml granule protein were adequate to lyse 100% of the erythrocytes, while the nucleated cells required up to 100 micrograms/ml granule protein to achieve complete lysis. Cytoplasmic granules purified from noncytotoxic lymphoid cells did not contain detectable cytolytic activity; purified granules from rat mast cells and rat liver lysosomes likewise failed to display cytolytic activity. However, granules prepared from normal rat peripheral blood LGL were cytolytic. Granule-mediated lysis of erythrocytes and nucleated cells was complete within 3 min at room temperature. The lytic activity required calcium at concentrations of 10(-4)-10(-2) M; magnesium or barium failed to replace calcium, while strontium could replace calcium at 10(-3)-10(-2) M when nucleated cells were the target. Exposure of LGL tumor granules to calcium before the addition of target cells resulted in an inactivation of granule cytolytic activity over the course of 20 min at room temperature. Granule cytolytic activity was heat and Pronase sensitive, and could be solubilized by 2 M salt. Examination of granules exposed to calcium in the electron microscope using negative staining showed that calcium treatment of granules results in the formation of ring-shaped structures previously described to be associated with LGL-mediated cytotoxicity. These results provide support for the hypothesis that the cytotoxic processes mediated by LGL are a secretory event characterized by the release of cytolytic material from the cytoplasmic granules after triggering by a surface receptor. The results further suggest that the ring structures visible in the electron microscope are associated with the lytic event.

Animals↗
PubMed1984

Natural killer activity in the rat. IV. Distribution of large granular lymphocytes (LGL) following intravenous and intraperitoneal transfer.

Highly enriched populations of rat large granular lymphocytes (LGL) and T lymphocytes were prepared on discontinuous density gradients of Percoll, labeled with either 111In-oxine or 51Cr and injected either intravenously (iv) or intraperitoneally (ip) into normal syngeneic recipients. Following iv inoculation of labeled LGL or T cells into normal recipients, a large proportion of radioactivity (18 to 33%) was recovered within minutes in the lungs. By 2 to 4 hr following transfer, significantly more LGL (13.5%) than T cells (6.4%) remained in the lungs. This difference persisted through 48 hr (5.4 vs 0.8%). Decreasing levels of radioactivity in the lungs were accompanied by corresponding increases in counts in the spleen and liver. At early time points, a significantly higher proportion of T cells was found to distribute to the spleen, while labeled LGL persisted for longer periods in the blood as well as in the lungs. Following ip inoculation into normal recipients, there was a slow clearance of radiolabeled LGL and T cells from the peritoneal cavity, with less than 20% of the radiolabel found in peripheral organs by 24 hr. These results demonstrate a distribution pattern for LGL and T cells that resembles the previously reported proportions of these cells in various organs. In addition, these studies provide a firm basis for the formulation of further experiments to examine the usefulness of adoptive immunotherapy with LGL or immune T cells.

Animals↗
PubMed1984

Liposomes as targets for granule cytolysin from cytotoxic large granular lymphocyte tumors.

Purified cytoplasmic granules from rat large granular lymphocyte tumors having natural killer activity and/or antibody-dependent cell-mediated cytotoxicity induced a rapid, dose-dependent release of the water-soluble marker carboxyfluorescein from liposomes made of phosphatidylcholine. A solubilized, partially purified cytolytic preparation termed "cytolysin" from these granules showed identical properties. Marker release induced by granules or the cytolysin was strongly dependent on the presence of Ca2+ at a concentration of 0.1 mM or higher in the medium; Ca2+ could be replaced by higher concentration of Sr2+ but not by Ba2+ or by Mg2+. These properties strikingly parallel the lytic effects that granules and granule cytolysin exert on cells. Marker release from liposomes was stopped instantaneously when an excess of EGTA was added to the medium. The remaining carboxyfluorescein inside the liposomes was present at the original internal concentration, indicating that marker release was all-or-none from individual liposomes. Liposomes comprised of lipid in the solid phase released marker more slowly than did comparable liposomes containing fluid-phase lipids. Variation of the lipid headgroup had only minor effects on the cytolysin-induced marker release. Electron microscopy of liposomes exposed to cytolysin in the presence of Ca2+ showed cylindrical structures of 15-nm diameter inserted into the membrane concomitant with the penetration of negative stain into the liposome. These properties of large granular lymphocyte granule cytolysin strongly suggest that it operates through a mechanism similar to the membrane attack of complement.

Animals↗
PubMed1984

Papovaviral sialoadenitis in athymic nude rats.

A wasting disease was found in 32 athymic nude rats. The rats had parotid sialoadenitis with intranuclear inclusion bodies in ductal and acinar epithelial cells. Other common lesions included bronchitis, bronchiolitis and secondary bacterial pneumonia. Less commonly, rhinitis and Harderian adenitis were seen. Intranuclear inclusions were also seen in bronchial epithelium of 1 rat, Harderian gland acini of 1 rat and laryngeal glands of 2 rats. Viral particles, averaging 45 nm in diameter, sometimes in crystalline arrays, were found in the nucleus of parotid epithelial cells. By the use of the avidin-biotin-peroxidase complex (ABC) immunoperoxidase technique, antibodies to disrupted SV40 virus (the group specific antigen of the polyomavirus (miopapovavirus) genus of the papovavirus family) reacted with intranuclear inclusions and cytoplasm of parotid epithelium and inclusions in lung and Harderian gland. The viral antigen did not cross react with antibodies to mouse polyoma, mouse K or disrupted bovine papilloma viruses.

Animals↗
PubMed1984

Natural killer activity in the rat. III. Characterization of transplantable large granular lymphocyte (LGL) leukemias in the F344 rat.

Six transplantable large granular lymphocyte (LGL) tumor lines in F344 rats were examined for natural killer (NK) and antibody-dependent cell-mediated cytotoxicity. Tumor cells from all six lines were highly cytotoxic, even at low effector to target ratios, when tested against NK-susceptible targets, but were unreactive against an NK-resistant target (C58NT)D) and a macrophage-susceptible target (P815). Three lines showed significant levels of lysis against antibody-coated tumor cells. After in vivo transplantation, the levels of cytotoxicity steadily increased in three lines and decreased in one. The cytotoxic activity of one line (RNK-16) remained high through 12 transplant generations. Tumor cells injected i.p. spread via the lymphatics to regional lymph nodes, mediastinal nodes, blood, and eventually the bone marrow. Leukemia occurred concurrently with organ enlargement and increased levels of NK. Studies in (F344 X W/Fu)F1 rats clearly demonstrated that the cytotoxic cells from leukemic animals were the transplanted tumor cells themselves and not merely the activation of normal host LGL. These results demonstrate that naturally occurring, transplantable LGL leukemias are an easily obtainable and excellent source of materials for those studies requiring a large number of functionally active LGL.

Animals↗
PubMed1984

T gamma-lymphoproliferative disease and related disorders in humans and experimental animals: a review of the clinical, cellular, and functional characteristics.

T gamma lymphocytes are those lymphocytes that express receptors for both the Fc portion of IgG and sheep erythrocytes. A very high proportion of normal T gamma lymphocytes are large granular lymphocytes (LGL), the cell responsible for most, if not all, natural killer (NK) and antibody-dependent cell-mediated cytotoxicity (ADCC) in humans, rats, and mice. In general, these cells are large lymphocytes with prominent azurophilic granules in the cytoplasm. Recently, a group of lymphoproliferative disorders made up predominantly of T gamma lymphocytes has been described. The most common and best studied of these disorders we refer to as "chronic T gamma-lymphoproliferative disease" (T gamma-LPD). In most cases, this disease represents the abnormal expansion of LGL, which is reflected by an increase in functionally active NK or ADCC effector cells. The chronic T gamma-LPD lymphocytes are generally characterized as E- and EA-rosette positive, acid-phosphatase, and beta-glucuronidase positive and express the pan-T antigens OKT3/Leu-4, OKT11/Leu-5, the suppressor-associated antigens OKT5,8/Leu-2, and the NK-associated antigens Leu-7/HNK-1. Typically, the patients are older, predominantly males and characteristically have a lymphocytosis of predominantly T gamma lymphocytes with lymphocyte infiltration of the bone marrow and often the spleen. While chronic T gamma-LPD is not usually an aggressive disease, the patients are often neutropenic and have recurrent bacterial infections requiring antibiotic therapy. Some patients have benefited from cytotoxic chemotherapy., but most patients have not required chemotherapy. An experimental LGL leukemia in F344 rats appears morphologically, functionally, and clinically similar to the human chronic T gamma-LPD and serves as an experimental model for further examining the ontogeny and function of LGL and may be applicable for exploring new and more effective means for the treatment of patients with chronic T gamma-LPD.

Adult↗