The effect of piroxicam on interleukin production and responsiveness in patients with ankylosing spondylitis

Interleukin (IL) production and responsiveness of peripheral blood lymphocytes (PBL) from 10 patients with ankylosing spondylitis (AS) were compared with that of 15 age-matched control subjects. Patients discontinued all antiinflammatory medication seven days prior to testing. After the initial assessment, piroxicam 20 mg daily was given to five patients for 30 days and the studies repeated. Interleukin was generated by the addition of staphylococcal protein A (SpA) to serum-free microcultures of PBL. 48-hour culture supernatants were assayed for interleukin by determining their capacity to induce mouse thymocyte proliferation in the presence of a suboptimal dose of concanavalin A. Interleukin activity was quantified by profit analysis of enhanced³H-thymidine uptake. Normal resting PBL are unable to respond to IL-2 without prior activation. Thus responsiveness to interleukin was determined by culturing PBL for 48 hours with or without SpA and exposing the cells to an internal laboratory interleukin standard.³H-thymidine uptake was measured after a further 4 days.The production of interleukin by PBL from AS patients (23.9±6.0 IL units/ ml) was comparable with that from control subjects (23.4±8.9 units/ml). Interleukin generation in the five patients given oral piroxicam was similar before (27.0±6.2 units/ml) and after therapy (23.6±9.3 units/ml). Also similar were the minimal responsiveness to exogenous interleukin of resting PBL from controls as well as AS patients pre- and post-piroxicam therapy. This last observation is in contrast with previous data from patients with recently active rheumatoid arthritis whose PBL were responsive to exogenous interleukin even without prior mitogenic stimulation. When cultures were pre-activated with SpA before being exposed to interleukin, PBL from untreated AS patients showed enhanced responsiveness to exogenous interleukin (mean cpm 183,000±95,472) when compared with control subjects (mean cpm 97,914±96,232). This difference was not statistically significant. However, following piroxicam therapy in four of five patients, the enhanced responsiveness was partially reversed towards normal (mean cpm 251,360±73,382 to 170,300±69,237). Further studies on the effect of piroxicam in prostaglandin mediated enhanced proliferation of PBL to mitogens or interleukin may be fruitful.     

Anti-thyroid drugs and lymphocyte function. I. The in vitro effect on blastogenesis and suppressor cell activity

The in vitro effect of the anti-thyroid drugs (ATD), propylthiouracil (PTU) and methimazole (MMI) on blastogenesis of peripheral blood mononuclear cells (PBMC) from healthy subjects was studied in 72 hr PHA stimulated cultures. PTU in therapeutic concentrations (10 micrograms/ml) suppressed blastogenesis only when added at the last 18 hr of culture, while at 100 micrograms/ml significant suppression (25%) was recorded also for PTU present throughout culture. PTU had no cytotoxic effect on Raji cells as tested by 51Cr release assay and 3H-thymidine incorporation. Moreover, strong and irreversible suppression (33%) was induced in resting PBMC on 1 hr pre-incubation with PTU. These findings and the fact that suppression was recorded only in cultures exposed to suboptimal concentration of PHA (0.5 micrograms/ml) speak against a direct anti-metabolic effect. MMI in therapeutic concentration (1 microgram/ml) and tri-iodothyronine (T3) in pharmacological concentration (10(-7)M) were much less active. Suppression of blastogenesis by PTU appeared to be mediated through suppressor cell enhancement as indicated by: (a) the augmented blastogenesis following 24 hr pre-incubation, commonly ascribed to suppressor cell depletion, was blunted by pre-incubation with PTU; (b) mixing PTU pre-treated with untreated cells reduced the expected response to PHA and (c) PTU pre-incubated, mitomycin treated cells suppressed blastogenesis of autologous or allogeneic responder cells.     

Soluble interleukin-2 receptor and soluble CD8 antigen in active rheumatoid arthritis

Concentrations of soluble interleukin-2 receptor (sIL-2R) and of soluble CD8 antigen (sCD8) in sera and in supernatants of phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) derived from patients with active rheumatoid arthritis (RA) were studied. sIL-2R concentrations in sera derived from patients with RA (1484 +/- 382 U/ml) were significantly higher than in sera derived from healthy controls (380 +/- 110 U/ml; P less than 0.0005). In contrast, supernatants of PHA-stimulated PBMC derived from patients with RA contained similar amounts of sIL-2R (727 +/- 467 U/ml) as those derived from healthy control individuals (833 +/- 508 U/ml; P greater than 0.1). When investigated for the presence of sCD8 antigen, sera derived from patients with RA contained significantly lower amounts (30 +/- 28 U/ml) than sera derived from healthy controls (405 +/- 136 U/ml; P less than 0.0005). Similarly, PHA stimulation of PBMC derived from patients with RA resulted in a significantly lower production of sCD8 (35 +/- 46 U/ml) as compared to the one obtained by PHA stimulation of PBMC derived from healthy controls (177 +/- 59 U/ml; P less than 0.0005). This difference could not be explained by a lower proliferative response to PHA by PBMC derived from patients with RA (21,474 +/- 14,022 cpm) as compared to healthy controls (29,549 +/- 11,188 cpm; P greater than 0.05). Our data demonstrate that PBMC derived from patients with active RA differ from PBMC derived from healthy individuals concerning their ability to produce sIL-2R and sCD8.     

Effect of thymic hormone treatment on several immune functions of nude mice

Studies of the effect of short-term, intense treatment with thymic hormone on mitogen response, cytotoxicity to EL-4 lymphoma and natural killer cell (NK) activity was investigated Balb/c nude mice (about 12-16-week-old) were treated 5 times per week for 3 weeks with: Facteur Thymic Serique (FTS) and Thymopentin (TP5, Thymopoietin 32-36) at 1 microgram and 10 ng; TM4 1 ng (an enzyme resistant variant of FTS); Thymosin Fraction V (TF5), 10 and 1 microgram; and 0.1 ml saline, and killed 2 days after the last treatment. The animals were monitored for changes in weight, hematocrit, peripheral blood lymphocyte (PBL) and spleen mitogen response. Additional groups of nude mice were immunized with 1 x 10(7) 5000 R irradiated EL-4 cells 10 days before sacrifice and tested for the presence of cytotoxic T-lymphocytes (CTL). The results show that weight and hematocrit were similar among the groups. Treatment with FTS significantly elevated the number of PBL. Spleen stimulation in mice treated with 1 microgram TP5 was depressed to mitogen concanavalin A (ConA) and lipopolysaccharide (LPS) stimulation. The phytohemagglutinin (PHA) response was not different among the treatment groups. The PBL mitogen response to ConA and LPS was generally increased over saline control in the hormone treated groups but was not statistically significant. The PHA response was only slightly elevated. No CTL was generated in nude mice in any of the groups. However, there was a statistically significant general depression of NK activity in all of the hormone treated animals compared with saline. The results indicate that the basic differentiation defect of the T-cells of nude mice cannot be restored to full functional activity by short-term treatment.     

Experimental infection of human leukocytes with parainfluenza 1 (6/94) virus.

Parainfluenza 1 (6/94) virus replicated in both unstimulated and phytohemagglutinin (PHA)-stimulated human peripheral blood leukocytes (PBL). After exposure of PBL to 6/94 virus at a multiplicity of infection of 1, the presence of viral antigen was demonstrated by immunofluorescence in the cytoplasm of less than 1% of unstimulated PBL and 1 to 5% of macrophages. Small amounts (less than 50 mean egg infective doses per ml in most instances) of cell-free virus were present in 18 of 30 (60%) cell cultures tested from 3 to 8 days postinfection. Cell-free virus peaked 6 days postinfection. Virus replication was enhanced in PHA-stimulated cells. Approximately 1 to 10% of PHA-stimulated PBL contained viral antigen as evidenced by immunofluorescence, and cell-free virus was present in 19 of 25 (76%) of the cell cultures tested from 3 to 8 days postinfection. Paramyxovirus nucleocapsids and tubular aggregates were seen in the cytoplasm of approximately 5% of PHA-stimulated PBL and were visualized only in lymphocytes. No other unusual intracytoplasmic or intranuclear structures were seen.     

Lymphocyte response to T-cell mitogen during experimental gingivitis in humans.

This study was conducted to evaluate the dose response relationships of peripheral blood lymphocytes (PBL) by stimulation of phytohemagglutinin (PHA) during the onset of oral inflammation. Eleven dental students underwent a 3-week experimental gingivitis program (Löe et al., 1965). At time zero, weeks 1, 2, and 3, and after 1 week of reinstituted oral hygiene (week 4), the plaque accumulations were evaluated, the degree of gingival inflammation was assessed, and a blood sample was taken. Quadruplicate microcultures each containing 2 x 10(5) PBL in 0.2 ml of tissue culture medium 199 and 10% fetal calf serum were stimulated with five concentrations of PHA (10 to 0.5 mug/ml) and incubated for 78 h at 37 C in 5% CO2. [3H]thymidine was added to each culture for the final 8 h. The cultures were then harvested and counted by liquid scintillation, and stimulation indexes (SI) were determined. At time zero the maximum PBL response occurred at a PHA concentration of 5 mug/ml (SI = 100). During weeks 1, 2, and 3 the location of the maximum PBL response shifted to a lower PHA concentration (1.0 mug/ml) and increased to over SI =400. The phenomenon of shifting peak PHA responses to lower PHA concentrations could be observed after only 1 week of developing gingival inflammation. The PBL response returned to pre-experimental values after 1 week of reinstituted oral hygiene, which resolved the oral inflammation. The findings show that a dose response relationship exists between PHA concentrations and the PBL response. If these dose response changes seen during developing gingival inflammation are ignored, either a decrease, increase, or no change in PBL response can be shown depending upon the PHA concentration evaluated. Owing to the dose-dependent nature of this PBL response, it is advisable to routinely use dose response curves in order to properly evaluate the full responsiveness of PBL to mitogenic substances.     

Phagocytosis of unopsonized zymosan particles by trypsin-sensitive and β-glucan-inhibitable receptors on bone marrow-derived murine macrophages

Murine bone marrow cells, plated at 4 X 10(4) cells/well and cultured in 50% fibroblast CM, yielded pure populations of large, individual, adherent cells that were phagocytic and morphologically indistinguishable from macrophages. Adherent macrophages appeared in small numbers with 24 h of culture, increased to maximal cell numbers within 10 days of culture, and remained at these cell densities for at least 11 weeks in culture. The capacities of adherent macrophages to ingest unopsonized zymosan particles and EsIgG, at inputs of 1.25 X 10(7) targets, were expressed by 7 and 40% of the cells derived from 24-hour cultures, respectively, were increased at nearly identical rates to comparable maximal levels within 10-14 days of culture and were exhibited by essentially all adherent cells derived from 2-11-week cultures. The percentage of adherent macrophages from twelve 3-6-week cultures ingesting greater than or equal to 1, greater than or equal to 6 and greater than or equal to 10 zymosan particles was 89 +/- 5, 47 +/- 11 and 14 +/- 9% (mean +/- SD, n = 12), respectively, and the percentage ingesting greater than or equal to 1, greater than or equal 6 and greater than or equal to 10 EsIgG was 86 +/- 5, 49 +/- 10 and 14 +/- 8%, respectively. Incubation of adherent macrophages with mannan-free ss-glucan particles at inputs of 5 X 10(5)-5 X 10(7)/ml initiated a phagocytic response comparable to that obtained with the same doses of zymosan particles which contained mannan and beta-glucan. Preincubation of adherent macrophages with 100 micrograms/ml of a fully soluble beta-glucan, laminarin, and solubilized barley beta-glucan reduced subsequent macrophage phagocytosis of greater than or equal to 6 zymosan particles by 53 and 40%, respectively. In contrast, yeast alpha-mannan was less than 1% as active, and 10 mg/ml reduced the number of adherent macrophages ingesting greater than or equal to 1 zymosan particles by 64%. At concentrations as high as 2 mg/ml, laminarin and barley beta-glucan had no effect on Fc receptor-mediated ingestion of EsIgG, and mannan at 20 mg/ml also failed to inhibit EsIgG ingestion. Pretreatment of adherent macrophages with 20 micrograms/ml of trypsin reduced the number of cells ingesting greater than or equal to 1 zymosan particles from 89 to 10% and those ingesting greater than or equal to 6 zymosan from 43 to 0%, whereas pretreatment with as much as 100 micrograms/ml of trypsin failed to decrease macrophage ingestion of EsIgG.(ABSTRACT TRUNCATED AT 400 WORDS)     

Lectin interactions with the Jurkat leukemic T-cell line: quantitative binding studies and interleukin-2 production

Phytohemagglutinin (PHA), concanavalin A (Con A), pea lectin, and wheat germ agglutinin (WGA) have been used to investigate their binding properties to Jurkat 77 6.8 leukemic human T cells and their ability to induce these cells to produce interleukin-2 (IL-2). Binding studies showed that the Jurkat cells fixed 0.82 +/- 0.11 microgram pea lectin, 2.02 +/- 0.17 micrograms Con A, 1.85 +/- 0.07 micrograms PHA and 8.88 +/- 0.61 micrograms WGA. Scatchard plots were linear, indicating that the binding process was homogeneous with respect to the binding constant. PHA and Con A bound with the highest affinity [Kass (apparent) approximately equal to 9 x 10(9) M-1], followed by pea lectin and WGA [Kass (apparent) approximately equal to 3 x 10(9) M-1]. The number of lectin binding sites was in agreement with the results of saturation experiments. We also evaluated the effect of the presence of 12-O-tetradecanoylphorbol-13-acetate (TPA) on the binding process. Results show that there were no gross alterations in the value of (apparent) Kass in the case of PHA and WGA. In contrast, the presence of TPA decreased the affinity of Con A and modified the Scatchard profile for pea lectin, which was curvilinear with a concavity turned upward. In this case, data were (apparent) K1 = 17.7 x 10(9) M-1 ("high-affinity" sites) and (apparent) K2 = 2.6 x 10(9) M-1 ("low-affinity" sites). The four lectins shared the ability to stimulate Jurkat 77 6.8 cells to secrete IL-2. Optimal lectin concentrations were 20 micrograms/ml (PHA) and 50 micrograms/ml (WGA and Con A). Pea lectin failed to display a dose-response relationship, and IL-2 production increased proportionally with lectin concentration. Con A was the most efficient stimulator (250 U/ml), followed by WGA (160 U/ml) and PHA (108 U/ml). Addition of TPA potentiated Jurkat cell response. In this case, Con A and pea lectin were the most efficient stimulators (470 U/ml), followed by PHA (316 U/ml) and WGA (271 U/ml). Here, also, pea lectin failed to show a dose-response relationship. Our data do not reveal an obvious relationship between the binding parameters and the ability of the lectins to induce IL-2 production. We suggest that the efficiency of the four lectins to stimulate IL-2 production in the case of the Jurkat 77 6.8 variant is most likely related to the nature of their specific cell surface receptor(s).     

Influence of inactivated feline retrovirus on feline alpha interferon and immunoglobulin production.

The effect of ultraviolet-inactivated feline leukaemia virus (UV-FeLV) on the development of feline immunoglobulin-secreting cells (ISC) was investigated using a reverse haemolytic plaque assay. Low concentrations of UV-FeLV at 2 X 10(-4) to 2.0 micrograms/ml stimulated the production of ISC. By contrast, the same concentration of UV-FeLV suppressed the development of pokeweed mitogen (PWM)-driven ISC. Maximum suppression of ISC occurred at 50 micrograms/ml of UV-FeLV. The generation of an interferon resistant to acid, heat and sodium dodecyl sulphate (SDS) in the media of lymphocyte cultures incubated with PWM was also significantly suppressed in the presence of 0.2 microgram/ml of UV-FeLV. These findings suggest that non-infectious viral particles appear to modify feline immunoglobulin and interferon-secreting systems.     

Mitogenic activity of 12-O-tetradecanoyl phorbol-13-acetate on peripheral blood lymphocytes from young and aged adults.

The effect of age on the proliferative response to 12-O-tetradecanoyl phorbol-13-acetate (TPA) was examined using peripheral blood lymphocytes from 185 adults. TPA-induced DNA synthesis measured by cellular 3H-thymidine incorporation was found, like the responses of cells activated by PHA and Con A, to markedly diminish with advancing age. The presence of indomethacin (1 microgram/ml) or Ro 20-5720 (10 micrograms/ml) in TPA activated cell cultures, unlike PHA stimulated cultures, did not result in augmentation of 3H-thymidine incorporation by cells from elderly individuals. These results demonstrate that prostaglandin synthesizing suppressor cells are not responsible for the age-related depression of cellular immune function observed in TPA activated cells and confirm the observation that decreased production and/or utilization of soluble mediators, such as IL-2, may account for the diminished mitogen responsiveness of lymphocytes from elderly individuals.     

Differential release of mediators from human basophils: differences in arachidonic acid metabolism following activation by unrelated stimuli

We have examined the release of histamine and LTC4 from purified human basophils challenged with several different stimuli, both physiological and nonphysiological. Basophils (n = 16) challenged with 0.1 micrograms/ml anti-IgE released 38 +/- 4% of their available histamine and 39 +/- 12 ng LTC4/10(6) basophils within 15-30 min. F-Met peptide (n = 8) caused the release of 54 +/- 8% histamine and 42 +/- 25 ng LTC4/10(6) basophils within a period of 2-5 min. C5a caused the release of 22 +/- 3% histamine from selected donors but failed to initiate any LTC4 release unless combined with D2O or 5 mM extracellular calcium. The two nonphysiological stimuli A23187 and TPA caused extensive histamine release, 67 +/- 8 and 82 +/- 11%, respectively, and while A23187 initiated a large and rapid release of leukotriene, TPA failed to release any LTC4 even when combined with D2O or 2-5 mM extracellular calcium. Increased concentrations of extracellular calcium enhanced anti-IgE and f-Met peptide induced release of LTC4 but inhibited the A23187 induced release of leukotriene. A single peak of immunoreactive leukotriene C4 that comigrated with the authentic standard was identified using HPLC followed by radioimmunoassay. No LTD4 or LTE4 could be detected. Purified human basophils incubated with 0.2 microM [3H]AA incorporated 290 pmol/10(6) cells, or 32 +/- 5% of the available label within 60 min. The [3H]AA was taken principally into the phospholipids (73 +/- 5%), with 20 +/- 3% as neutral lipid, and only 5 +/- 2% remaining as the free acid. Three phospholipid subclasses, phosphatidylcholine, PC (24 +/- 2%), phosphatidylinositol, PI (22 +/- 1%), and phosphatidylethanolamine, PE (15 +/- 3%), accounted for the majority of the incorporated [3H]AA while the remainder of the phospholipids accounted for less than 5% of the total cpm. HPLC analysis of the lipid mediators released during stimulation with 0.1 micrograms/ml anti-IgE revealed [3H]LTC4 (2.4 +/- 1.0%), [3H]5HETE (1.0 +/- 0.1%), unmetabolized [3H]AA (91 +/- 2%), and an unidentified peak (3.4 +/- 1.4%). The unknown metabolite eluted with the prostaglandins, was inhibited by indomethacin, and appeared to have a relatively high specific activity. It may thus represent an artifact of the labeling procedure rather than a novel basophil-derived prostaglandin.     

1 alpha,25-dihydroxyvitamin D3 inhibits pokeweed mitogen-stimulated human B-cell activation: an analysis using serum-free culture conditions.

The effect of 1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on pokeweed mitogen-induced generation of human immunoglobulin-secreting cells (ISC) was studied in serum-free culture. Human peripheral blood mononuclear cells (1.75 X 10(6)/ml) were cultured in 200 microliter microculture wells containing Iscove's MEM supplemented with 20 micrograms/ml of human transferrin, 20 micrograms/ml of soybean lecithin and 1 mg/ml of delipidated bovine albumin. The culture supported ISC generation of all isotypes, and the optimal concentration of pokeweed mitogen was 1 microgram/ml. After stimulation with a suboptimal concentration (0.3 micrograms/ml) of pokeweed mitogen, 1,25-(OH)2D3 suppressed the ISC generation at a dose range between 10(-9) M and 10(-7) M, and maximal inhibition was obtained at 10(-7) M. 1,25-(OH)2D3 had no effect on the spontaneous ISC generation. The effect was specific for 1,25-(OH)2D3 and no suppression was obtained by 24R,25-dihydroxyvitamin D3 or 25-hydroxyvitamin D3.     

T helper/inducer (CD4+) cells prestimulated with PPD induce monocytes to produce interleukin-1 beta.

We obtained peripheral blood mononuclear cells (PBMC) from four healthy, tuberculin purified protein derivative (PPD) reactive donors and cultured these cells in media containing PPD (low dose = 200 ng/ml or high dose = 1 micrograms/ml). Five days after the addition of PPD, T cells were isolated, washed, and added to autologous adherent cell cultures at a 1:1 ratio. Adherent cells were then cultured for 24 h in media only (baseline), media plus lipopolysaccharide (LPS, 2 micrograms/ml; positive control), or media containing the prestimulated T cells. After 24 h, supernatants were harvested and interleukin 1 beta (IL-beta) levels were assayed by radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA). The results show that T cells prestimulated with low dose PPD (200 micrograms/ml) did not induce IL-1 production by adherent cells (mean increase over baseline 0.2 +/- 1.3 standard deviation [SD] ng/ml, P = 0.61). However, T cells prestimulated with high dose PPD (1 microgram/ml) did induce adherent cells to secrete IL-1 beta (mean increase over baseline 1.7 +/- 0.62 [SD] ng/ml, P = 0.01), but this induction was abolished when cell-to-cell contact was prevented by use of double well chambers (mean increase over baseline 0.1 +/- 0.36 [SD] ng/ml, P = 0.69). Prestimulated T helper (CD4+) cells were able to induce monocytes to secrete IL-1 beta but prestimulated CD8+ T cells were not. These data suggest that when T helper (CD4+) cells are sufficiently activated they acquire the ability to induce monocytes to secrete IL-1 beta. Cell-to-cell contact between monocytes and T cells is required. This function of activated T cells may be important in the normal cellular immune response.     

Disulfiram as a radiation modifier

The radiation modifying effect and toxicity of tetraethylthiuram disulfide (disulfiram) have been studied. Disulfiram (DSM) inhibits aldehyde dehydrogenase, dopamine-beta-oxygenase, microsomal mixed-function oxidases and cytochrome P-450 enzymes. It is widely used for aversion therapy in alcoholism. Disulfiram also inhibits tumor formation by several known carcinogens. A biphasic toxicity pattern of DSM is reported in the L-929 mouse fibroblast culture system. Disulfiram is 100 percent toxic at 2 X 10(-7) M (0.05 micrograms per ml), 23 percent toxic at 3 X 10(-7) M (0.1 microgram per ml), and 100 percent toxic again at 3.4 X 10(-6) M (1.0 microgram per ml). The pattern is similar to the biphasic toxicity pattern of DMS's major metabolite, sodium diethyldithiocarbamate (DTC). Reports of both radiation protection and radiation enhancement by DTC exist. Previously, a radioprotective effect by 2 X 10(-6) M DTC (dose modifying factor = 1.26) has been demonstrated in the L-929 cell system. To date, no radiation modifying properties of DSM have been reported. Our investigation of DSM as a radiation modifier at 3 X 10(-7) M (0.1 microgram per ml) did not show significant improvement in survival of irradiated cells treated with DSM relative to the irradiated control group, as determined by absence of a difference in the Do of the two groups. Considering DSM's close structural relationship to DTC, it is possible that DSM may exhibit a radioprotective effect when applied in a different concentration than what was used in our research.     

Duck lymphocytes. II. Culture conditions for optimum transformation response to phytohaemagglutinin

The lymphocyte transformation (LT) test was performed with duck blood lymphocytes in 96-well microtitre trays against nine concentrations (0.1-100 micrograms/ml) of phytohaemagglutinin (PHA). It was found that incubation at 41.6 degrees C (duck body temperature) gave better results than incubation at 37 degrees C, and that a 6 h pulse with [3H]thymidine gave better results than an 18 h pulse. Cell concentration was very critical: successful duck LT required rather high concentrations of cells (approximately 4 X 10(6)/ml, equivalent to approximately 8 X 10(5)/culture) while lower and higher concentrations gave inferior results. Duck serum supported LT optimally when used at a concentration of 10-15%, but a serum pool from adult (approximately 6-month-old) ducks gave superior results to sera from younger birds. Foetal calf serum supported duck LT strongly when used at 20%, but only poorly at 10%, while chicken serum supported duck LT when used at 5-20%. Ultroser G was an ineffective supplement, and the addition of 5% tryptose phosphate broth to other supplements had variable effects. Using optimum culture conditions, maximum LT responses were obtained after 2-3 days' culture, when it was possible to obtain stimulation indices of 500-5000. The addition of PHA to cultures could be delayed for up to 18 h without affecting LT, but thereafter the cells rapidly lost responsiveness.     

Investigations on magnesium and chromium antagonism in the skin of experimental animals.

Investigations were performed over 30 days on 25 male rats Wistar breed divided into five groups. Animals received intraperitoneally (i.p.) potassium dichromate (KDCH) 5 mg/kg (basal doses, b.d.), 2 mg/kg (0.4 b.d.) and 100 mg Mg Cl2/kg body weight (b.w.). In performed investigations the highest concentration of chromium in animal skin 1.17 +/- 0.11 micrograms/g was observed by i.p. administration of KDCH 5 mg/kg b.w. Simultaneous i.p. administration of KDCH 5 mg/kg b.w. and MgCl2 100 mg/kg b.w. resulted in significant lower concentration of chromium (in comparison to the preceding group) in animal skin: 0.8 +/- 0.2 microgram/g (p < 0.001). In i.p. administration of KDCH in the doses of 0.4 b.d. the concentration of Cr in the skin amounted to 0.55 +/- 0.1 microgram/g. Values of Cr in the skin in exposed groups were significantly higher than in the control group, (p < 0.001).     

Effect of anti-IL-6 and anti-10 monoclonal antibodies on the suppression of the normal T lymphocyte mitogenic response by steady state sickle cell disease sera

Previously published work has shown that sera from healthy sickle cell disease (SCD) patients inhibits normal lymphocyte mitogenic response to phytohemagglutinin (PHA) in vitro. The current study is to attempt to ascertain what effect antibody to type 2 cytokines, interleukin (IL)-6 and 10, have on the suppression of lymphocyte PHA response by SCD sera. Peripheral blood mononuclear cells (PBMC), separated by density gradient were obtained from 2 healthy normal donors. Sera from 50 healthy SCD patients, 50 normal healthy controls and pooled normal O, Rh+ (O+) sera were utilized in standard in vitro PHA stimulation of PBMC cultures. Mitogenic responses were expressed as mean counts per minute (cpm) of triplicate cultures. Fifty triplicate cultures of PHA stimulated normal PBMC were done with 10% normal pooled O+, normal control and SCD steady state sera only. In addition 50 cultures were done with SCD sera containing 1 microg/ml of anti-IL-6 monoclonal antibody, as well as 28 SCD serum cultures containing 1 microg/ml of anti-IL-10 monoclonal antibody. The final 11 SCD serum culture experiments contained a combination of both anti-IL-6 and anti-IL-10 antibody, each at the concentration of 1 microg/ml. Results revealed > 15% suppression of mitogenic response in the SCD sera supplemented cultures as compared to control sera in 47/50 (94%) and in 40/50 (80%) of normal pooled O+, as calculated by mean cpm. The degree of suppression ranged from 17% to 98% in individual experiments. The addition of anti IL-6 antibody alone significantly improved mean cpm (> 20%) in 19/50 (38%) of SCD serum responses compared to O+ sera and 23/50 (46%) of control sera. Complete correction occurred in 9/50 (18%) of all SCD serum suppressions as compared to O+ sera and 6/50 (12%) when compared to control sera. Similarly, anti-IL-10 antibody decreased suppression of the mean cpm of SCD serum cultures in 18/28 (64%) and completely corrected 3/18 (11%). The combined antibody data revealed >20% increase in mean cpm in 10/11(91%) experiments. Inhibitors of mitogenic response were present in a significant percentage of the SCD sera utilized in the present study. The significant corrective effects of both monoclonal antibodies would seem to support the original hypothesis that high circulating levels of type 2 cytokines may represent the cell-mediated dependent inhibitory factors expressed in the sera of many healthy SCD patients.     

Differentiation of Pasteurella haemolytica biotypes A and T with growth inhibitors.

Differentiation of type A and type T cultures of Pasteurella haemolytica was accomplished by paper disks containing 0.3 microgram of penicillin G, which produced zones of inhibition larger than 10 mm with type A but not with type T strains. Basic fuchsin (0.2 microgram/ml), brilliant green (0.005 microgram/ml), methylene blue (3.1 micrograms/ml) in brain heart infusion broth permitted the growth of type T but that of type A isolates.     

EFFECT OF ANTI-IL-6 AND ANTI-10 MONOCLONAL ANTIBODIES ON THE SUPPRESSION OF THE NORMAL T LYMPHOCYTE MITOGENIC RESPONSE BY STEADY STATE SICKLE CELL DISEASE SERA

Previously published work has shown that sera from healthy sickle cell disease (SCD) patients inhibits normal lymphocyte mitogenic response to phytohemagglutinin (PHA) in vitro. The current study is to attempt to ascertain what effect antibody to type 2 cytokines, interleukin (IL)-6 and 10, have on the suppression of lymphocyte PHA response by SCD sera. Peripheral blood mononuclear cells (PBMC), separated by density gradient were obtained from 2 healthy normal donors. Sera from 50 healthy SCD patients, 50 normal healthy controls and pooled normal O, Rh+ (O+) sera were utilized in standard in vitro PHA stimulation of PBMC cultures. Mitogenic responses were expressed as mean counts per minute (cpm) of triplicate cultures. Fifty triplicate cultures of PHA stimulated normal PBMC were done with 10% normal pooled O+, normal control and SCD steady state sera only. In addition 50 cultures were done with SCD sera containing 1 μg/ml of anti-IL-6 monoclonal antibody, as well as 28 SCD serum cultures containing 1 μg/ml of anti-IL-10 monoclonal antibody. The final 11 SCD serum culture experiments contained a combination of both anti-IL-6 and anti-IL-10 antibody, each at the concentration of 1 μg/ml. Results revealed > 15% suppression of mitogenic response in the SCD sera supplemented cultures as compared to control sera in 47/50 (94%) and in 40/50 (80%) of normal pooled O+, as calculated by mean cpm. The degree of suppression ranged from 17% to 98% in individual experiments. The addition of anti-IL-6 antibody alone significantly improved mean cpm (> 20%) in 19/50 (38%) of SCD serum responses compared to O+ sera and 23/50 (46%) of control sera. Complete correction occurred in 9/50 (18%) of all SCD serum suppressions as compared to O+ sera and 6/50 (12%) when compared to control sera. Similarly, anti-IL-10 antibody decreased suppression of the mean cpm of SCD serum cultures in 18/28 (64%) and completely corrected 3/18 (11%). The combined antibody data revealed > 20% increase in mean cpm in 10/11(91%) experiments. Inhibitors of mitogenic response were present in a significant percentage of the SCD sera utilized in the present study. The significant corrective effects of both monoclonal antibodies would seem to support the original hypothesis that high circulating levels of type 2 cytokines may represent the cell-mediated dependent inhibitory factors expressed in the sera of many healthy SCD patients.