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Biomedical subjects

M L Rodrick

Publications and source records attributed to M L Rodrick.

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

Immature T lymphocytes after injury characterized by morphology and phenotypic markers.

Changes in the peripheral blood mononuclear cell (PBMC) population in patients following both thermal and nonthermal injury were defined by both morphological characteristics and surface phenotype with the monoclonal antibodies T6, OKT9, OKT10, and OKIa1, using a fluorescence activated flow cytometer with gating to separate small cells of the lymphocyte series from larger forms. Lymphocytes with surface antigens that bind T6, OKT9, and OKT10 are rarely found in the peripheral blood of adult patients, except in those with malignancies of the lymphoid system. In both burn and trauma patients the percentage of lymphocytes in the PBMC population after Ficoll-Hypaque separation was significantly reduced as compared with normal controls due to increases in the number of granulocytes, large granular lymphocytes (LGL), and monocytes, often present in immature forms. T6 cells were found in significantly greater numbers in both burn and nonthermal injury patients than in a control group using both small and wide gate settings on the fluorescence-activated flow cytometer. Significant increases in the number of T9+ cells also were observed in both groups for a prolonged period following injury. Significantly increased numbers of the T10+ and Ia1+ cells were detected in burn patients. The response to injury, therefore, involves the appearance in the peripheral blood of immature cells that may express T6, T9, T10, and Ia1 surface antigens. These cells may be present in quantities otherwise seen only in malignant disease.

Adolescent↗
PubMed1987

A single dose of endotoxin activates neutrophils without activating complement.

Both complement (C) and neutrophils (PMN) are activated in critically ill patients. To evaluate the role of endotoxin in this response, we studied C activation products and PMN cell surface receptors in seven normal subjects before and after endotoxin (USRef 20 U/kg) or saline solution administered on separate occasions. By 4 hours, with endotoxin only, all subjects had myalgia, headache, an increase in body temperature and heart rate, and leukocytosis that returned to normal by 24 hours. At the same time, PMN cell surface receptors for the complement opsonin C3b increased, as measured by indirect immunofluorescence, rising to 251 +/- 44% of baseline by 4 hours (p less than 0.01) and remaining elevated at 24 hours (237 +/- 16%, p less than 0.01). PMN receptors for iC3b increased to 308 +/- 49% of baseline by 4 hours (p less than 0.02) and returned to normal by 24 hours. There was no change in plasma of C3a desArg, C4a desArg, and C5a desArg (4 hours: mean C3a: 153.4 +/- 11.5 ng/ml versus 176.2 +/- 16.2 ng/ml for saline solution, p = ns; C4a: 159.6 +/- 32 ng/ml versus 151.4 +/- 21 ng/ml, p = ns; C5a: undetectable). To confirm the lack of C activation, we examined PMN chemotaxis (CTX) to C5a for any impairment caused by prior in vivo exposure to C5a. CTX to C5a was unaffected (4 hours: 109% +/- 22% of normal versus 114% +/- 10% for saline solution, p = ns). PMN CTX to formyl-methionyl-leucine-phenylalanine and PMN phagocytosis and killing of S. aureus were also unaffected by endotoxin. Thus, a single dose of endotoxin produced a subjective febrile illness and precipitated sustained PMN activation as indicated by increased PMN cell surface complement receptor number in the absence of C activation.

Adult↗
PubMed1987

Neutrophil activation after burn injury: contributions of the classic complement pathway and of endotoxin.

We attempt to elucidate the mechanisms of neutrophil (PMN) activation after burn injury. We previously reported prolonged elevations of PMN cell surface complement (C) opsonin receptor levels after burn trauma with a corresponding period of depressed PMN chemotaxis to C5a, which suggests that the C product, C5a, was responsible for PMN activation. However, a lack of direct correlation of C activation with C receptor levels soon after injury raised the possibility of a second PMN-activating substance. We therefore investigated the effect of endotoxin (LPS) on the expression of the C receptors (CR1 and CR3) by normal human PMNs. Concentrations from 0 to 50 ng/ml of LPS 026:B6 caused a dose response increase in the PMN surface expression of CR1 and CR3 as assessed by monoclonal antibody binding and indirect immunofluorescence. The relative CR1-dependent fluorescence rose from a mean of 50 to 385 and CR3 from 50 to 300. Chelation by ethylenediaminetetra acetic acid (EDTA) did not influence this dose response, thus ruling out the possibility of C activation by LPS--an inference supported by the lack of complement activation observed with these concentrations of LPS in normal serum. A similar dose response was obtained in the absence of other cell types or serum, which implies a direct effect that mimicked that of C5a. To determine the mechanism of the later, prolonged C activation after burn injury, we next examined C activation products in 22 patients with burn injuries. Elevations of plasma C3a desArg were present and persisted for 50 days. Elevations were at maximum levels on days 9 through 13 postburn (mean +/- standard error of mean [SEM], 496 +/- 47 ng/ml versus normal 113 +/- 32; p less than 0.01). These were accompanied by elevations of C4a desArg (917 +/- 154 ng/ml versus normal 424 +/- 50; p less than 0.01), which are indicative of classic pathway activation. Finally, we examined PMN function, phagocytosis and percentage killing of Staphylococcus aureus, and found PMN function to be unaltered in the 22 patients. Thus PMN activation after burn injury appears to be caused by LPS soon after injury and by C5a later after injury and affects only selected PMN functions.

Adolescent↗
PubMed1986

Abnormalities of antibody production after thermal injury. An association with reduced interleukin 2 production.

Antibody (Ab) production was studied in 25 burned patients who were immunized with 0.5 mg of tetanus toxoid adsorbed. Anti-tetanus toxoid (TT) Ab was measured by hemagglutination, radial immunodiffusion, and an enzyme-linked immunosorbent assay, and the results for the patients were compared with those for five similarly immunized healthy controls. As measured by hemagglutination, 12 (63%) of 19 patients had lower Ab responses than all five controls (P less than .05 by chi 2), and the median Ab response during the period of maximum response was significantly less than that in controls (8 vs 15.5 log2 maximum dilution; P = .014). After the initial response, serum Ab levels were not maintained in patients, in contrast to controls. This pattern was demonstrated by all three assays; enzyme-linked immunosorbent assay demonstrated that IgG anti-TT Ab was the major class of Ab produced. In nine patients interleukin 2 production by T lymphocytes was measured simultaneously; it was significantly depressed throughout the study except during the period from 36 to 45 days. The Ab response was also impaired in this patient group. Since maintained antibody production in response to TT is known to be T-cell dependent, these results suggest that inadequate interleukin 2 production leading to reduced T-cell help may be responsible for the lack of a persistent Ab response in these burned patients.

Adolescent↗
PubMed1986

Suppression of natural killer-cell function in humans following thermal and traumatic injury.

Depressed cell-mediated and humoral immune functions have been reported to occur following severe thermal and traumatic injury. In this study we have questioned whether another immune function, natural killing (NK), is also disturbed in these injured patients. Twenty-two thermally injured patients with burns ranging from 5 to 75% of the total body surface area and 15 traumatically injured patients with injury severity scores ranging from 9 to 56 were followed postinjury and compared to 29 age-matched controls. NK activity was measured as the percentage cytotoxicity in chromium-51 release assays with K562 target cells. The more severely burned patients had significantly depressed NK activity for the 40-day period following injury that remained reduced for the duration of the study. Patients with lesser burns had reduced NK-cell function for the initial 10-day period postburn that returned slowly to the normal range. Traumatically injured patients had depressed NK-cell function during the 3- to 6-day period postinjury. The percentage of cells bearing phenotypic markers for the groups in which NK cells are found was either normal or elevated in these patients. A correlation was found between NK activity and interleukin 2 generation by mononuclear cells from these patients. In order to investigate the mechanism of NK suppression in these patients, NK-cell function was studied following the infusion of cortisol, epinephrine, and glucagon into volunteer subjects in amounts known to reproduce serum levels seen following injury of moderate severity. NK-cell function was reduced an average of 66% following infusion, suggesting that the inhibition of NK-cell function seen in patients may be mediated by the stress response to injury.

Adolescent↗
PubMed1986

Mechanisms of immunosuppression associated with severe nonthermal traumatic injuries in man: production of interleukin 1 and 2.

Depression of cell-mediated immunity in patients following severe traumatic injury has been well documented in vitro and in vivo. However, the exact mechanism of this defect is still controversial. In this study, we have investigated the ability of injured patients' peripheral blood mononuclear cells (PBMC) to produce two important immunoregulatory molecules, interleukin 1 (IL 1) and interleukin 2 (IL 2). Eighteen traumatic injury patients were studied during the course of their hospital stay and their results compared with a group of 18 normal age- and sex-matched controls. The results showed the following. (1) Production of IL 2 by normal PBMC in response to optimal doses of mitogen may vary with sex as well as age. (2) Adherent mononuclear cells from trauma patients produced at least as much IL 1 as normals. (3) IL 2 production, however, was markedly suppressed (normals, 1.6 +/- 0.2 U; traumatic injury, 0.6 +/- 0.1 U; P = 0.001) and persisted for as long as 50 days postinjury. OKT4+ cells were not significantly decreased at any time, nor were OKT8+ suppressor/cytotoxic cells increased at any time. Decreased IL 2 production in patients treated with steroids or those who were septic was not different from that in those patients who were not treated with steroids or were not septic. These results suggest that the cause of the defect in IL 2 production in traumatic injury patients is not related to a lack of the IL 1 signal, producer T cells, or Ia+ monocytes or to increased suppressor T cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed1985

Changes in T lymphocyte subsets following injury. Assessment by flow cytometry and relationship to sepsis.

The increased susceptibility of severely injured patients to infection and death from sepsis has been attributed to abnormalities in cell-mediated immunity. The authors therefore assessed the relative number of peripheral blood T helper cells and T suppressor/cytotoxic cells and total T lymphocytes identified by the monoclonal antibodies (McA) OKT4, OKT8, and OKT3, respectively, in 25 patients with burns from 5 to 85% total body surface area (TBSA) (mean: 40%) and 21 patients with nonthermal injuries (mean Injury Severity Score (ISS): 21.4). Patients were compared to 21 healthy controls. Cells reacting with the McA were detected by flow cytometry, which enabled the examination of a population of cells the size of T lymphocytes, excluding larger contaminating cells that might bind the McA. Patients with burns of 30% TBSA or greater had a significant reduction (p less than or equal to 0.05) in OKT3+ cells up to 50 days post-burn. Both septic and nonseptic burn patients had reduced numbers of OKT3+ cells, as did patients after nonthermal injury, suggesting that this reduction was due to the injury itself. Patients with smaller burns (less than 30% TBSA) as a group did not have reduced OKT4+ cells, whereas those with larger burns showed significant reductions in OKT4+ cells (P less than or equal to 0.05) at 0 to 5, 6 to 10, 11 to 20, 21 to 30, and 41 to 50 days post-burn. Seven burn patients who became septic 10 days post-burn or later had significantly lower OKT4+ cells within 10 days of injury (mean: 33.75% +/- 7.4 SEM) than 10 patients who remained free of sepsis (mean: 42.2% +/- 5.4, p = 0.004). Patients with uncomplicated nonthermal injuries failed to show any significant reduction in OKT4+ cells. Following thermal injury, a reduction in OKT8+ cells was observed up to 10 days in patients with burns less than 30% TBSA, and up to 20 days in patients with larger burns. In both groups, at no time were increased OKT8+ cells found to correlate with clinical events. In patients with nonthermal injury, OKT8+ cells generally remained near the normal range.

Adolescent↗
PubMed1984

Characterization of antigenic components from circulating immune complexes in patients with gestational trophoblastic neoplasia.

The authors have studied serial circulating immune complex (CIC) levels in 15 patients with gestational trophoblastic neoplasia (GTN) for several reasons. Gestational trophoblastic neoplasia can easily be followed from presentation to remission, and CIC changes can be compared with changes in human chorionic gonadotropin (HCG) which is a specific and quantitative marker of trophoblastic tumor load. Twelve patients with hydatidiform molar pregnancy presented with normal CIC levels (255 delta OD450 +/- 97, mean SE [standard error]) as measured by our antigen nonspecific polyethylene glycol (PEG) turbidity assay. Only after reduction in tumor load as monitored by a fall in HCG did CIC rise. In contrast, three patients with choriocarcinoma presented with significantly elevated CIC levels (513 delta OD450 +/- 147, P less than 0.05 compared to normals) which slowly declined in parallel with HCG levels following evacuation and chemotherapy. Sera at peak PEG-CIC from three patients with molar pregnancy or choriocarcinoma were precipitated with 3.75% polyethylene glycol to concentrate circulating immune complexes. Circulating immune complex levels were fractionated on Sephadex G-200 in an acid buffer (pH = 2.8). An identifiable antigenic component of the CIC in both diseases was found to be paternal HLA antigen. This was demonstrated by the ability of the latest eluting CIC fraction to inhibit paternal lymphocyte lysis using anti-HLA antisera against the husband's HLA tissue type. In each case, this fraction contained no immunoglobulin or beta-2 microglobulin and was antigenically crossreactive with only one of the husband's HLA haplotypes. The authors believe the PEG-CIC assay has allowed them to define the kinetics of host humoral response in GTN, and has provided a method for recovering immunogenic tumor-associated antigens from these complexes which may apply to other solid tumors.

Antigen-Antibody Complex↗
PubMed1984

The effect of 1,2-dimethylhydrazine (DMH) carcinogenesis on peripheral T cell subsets in the Wistar Furth rat.

1,2-dimethylhydrazine (DMH)-induced colon cancer in Wistar/Furth (W/Fu) rats is analogous in many ways to human colorectal cancer. As part of our attempt to understand the immunobiology of these tumors, we have utilized the recently available monoclonal antibodies W3/25 and OX8 to monitor helper (Th) and suppressor (Ts) lymphocyte subpopulations. Normal untreated male W/Fu rats of less than 1 year of age were phenotyped (n = 43). The mean percentage of Th and Ts was 42 +/- 1 (mean +/- SEM) and 33 +/- 1, respectively. The mean Th/Ts ratio was 1.3 +/- 0.1. A Th/Ts equal to or greater than 1 is considered "normal" in the W/Fu rat. The DMH-treated rats (20 mg/kg/wk) were evaluated in initial experiments at various intervals after treatment. Rats studied 24 hours after a single DMH injection had no alterations in T cell subsets. Rats studied 28, 32, and 65 weeks after the start of 16 weekly DMH injections were found to have a decrease in the percentage of Th and a relative increase in Ts, with Th/Ts ratios of 0.6 +/- 0.2, 0.7 +/- 0.1, and 0.7 +/- 0.1, respectively (each P less than 0.01). In a separate experiment in which rats were studied after 4, 8, and 16 weeks of DMH injections, no alterations in T cell subsets were noted. Rats (n = 5) studied at 20 weeks after the start of DMH were found to have 41 +/- 3% Th and 36 +/- 2% Ts and a Th/Ts ratio of 1.2 +/- 0.1. Three of five rats were found to have adenocarcinomas. Four of five rats had Th/Ts less than 1. One rat with Th/Ts equal to 0.9 had metastatic disease. Rats studied at 25 weeks (n = 8) were found to have more advanced carcinomas (4/8) that were causing obstruction or bleeding in the animal. There was a significant decrease in Th and Ts in this group, with 24 +/- 3% and 26 +/- 3% respectively (P less than 0.001). The Th/Ts ratio for this group was 0.9 +/- 0.1 (P less than 0.01). In other experiments, rats were treated with DMH or placebo over a 16-week period and serially bled during and after treatment. No effect of DMH treatment on T cell subsets was noted. Repeated bleeding alone was noted to cause persistent alterations of T cell subpopulation.(ABSTRACT TRUNCATED AT 400 WORDS)

1,2-Dimethylhydrazine↗
PubMed1984

Inadequate interleukin 2 production. A fundamental immunological deficiency in patients with major burns.

We studied the production of the two major mediators of cellular immune responses, Interleukin 1 (IL-1) and Interleukin 2 (IL-2), by the peripheral blood mononuclear cells of 23 burn patients (16 men, seven women, mean age 48.9 years) compared with 23 matched controls (16 men, seven women, mean age 46.7 years). Serial measurements were made of IL-1 production by adherent mononuclear cells after stimulation with lipopolysaccharide and of IL-2 production by lymphocytes after stimulation with phytohemagglutinin (PHA). Eighty determinations of IL-2 production by lymphocytes from 12 patients with greater than 30% body surface area burn revealed a mean IL-2 production of 0.71 u as compared with a mean of 1.23 u for patients with less than 30% burns (p = 0.04). Patients with greater than 30% body surface area burns had significantly reduced IL-2 production (p less than or equal to 0.05) until 60 days after injury, whereas those with smaller burns had reduced IL-2 production only at 20-29 and 30-39 days postburn. Nine burn patients with systemic sepsis showed significantly lower IL-2 production (p = 0.03) at 10-29 days postburn than nonseptic patients, and significantly less IL-2 production during septic episodes. Eight patients with greater than 50% suppression of lymphocyte response to PHA produced less IL-2 (0.4 u) than patients with less than 50% suppression, (1.07 u, p = 0.004). IL-1 production was significantly elevated as compared with controls (4.45 u vs. 3.6 u, p = 0.05) early after injury, but was subsequently within the normal range regardless of burn size. The percentage of circulating helper T-lymphocytes, the principal source of IL-2, was also reduced, although this did not always correlate with IL-2 production, which remained depressed after recovery of the helper T-cell population. These results indicate that failure to produce IL-2, a powerful mediator of cellular immune responses, is an important mechanism underlying the defective cell mediated immunity seen in burn patients.

Adult↗
PubMed1984

Depression of cellular immunity after multiple trauma in the absence of sepsis.

We have previously reported that severe burn injury was regularly accompanied by impaired lymphocyte responses to T cell mitogens, circulating suppressor lymphocytes, and serum factors suppressive of lymphocyte activation. However, in burned patients it was difficult to determine whether these manifestations of suppressed immunity were predictive of, or the result of, sepsis which was ubiquitous in this population. In an attempt to clarify this issue, we have studied 31 patients with multiple trauma (without burns) mean age, 31 years; average injury severity score, 22; range, 9-56; in whom sepsis was less common. Patients were tested for lymphocyte response to the T cell mitogens PHA and Con A, the percentage of circulating putative suppressor (OKT8) and helper (OKT4) T cells using monoclonal antibodies, circulating suppressor cell activity as revealed by functional assays, and serum suppression of lymphocyte activation. Patients were compared with ten normal volunteers (mean age, 32) studied simultaneously. Significant suppression (greater than 50% compared with controls) in lymphocyte responses to mitogens 1 to 5 days after injury was seen in 12 patients, was accompanied by a shift in the ratio of helper (OKT4) to suppressor (OKT8) T cells (patients, 0.96:1; normals, 1.82:1; p less than 0.01), and was followed by the appearance of significant (greater than 50%) serum suppressive activity in six of the 12 patients. Circulating suppressor cell activity as revealed by functional assays was also seen early after injury in three of 12 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Identification of material with paternal HLA antigen immunoreactivity from purported circulating immune complexes in patients with gestational trophoblastic neoplasia.

Circulating immune complex(es) (CIC) have been shown to rise progressively only when patients with hydatidiform molar pregnancy enter gonadotropin-documented remission. The CIC in 3 patients with gestational trophoblastic neoplasia (GTN)--1 with hydatidiform mole and 2 with choriocarcinoma--were characterized. Their clinical course was monitored by serial antigen-nonspecific polyethylene glycol (PEG) 6000-CIC assay and simultaneous human chorionic gonadotropin (HCG) assay from presentation until sustained gonadotropin-documented remission. As serial HCG progressively decreased to normal following surgical or chemotherapeutic reduction in tumor burden, PEG-CIC concurrently rose. Serum obtained at or near peak PEG-CIC levels was precipitated by 3.75% PEG 6000 and fractionated by column chromatography on Sephadex G-200 (exclusion limit, greater than 600,000 mol wt) in glycine-HCl and 1 M NaCl buffer at pH 2.8. None of the 5 elution fractions obtained from the 3 patients contained HCG or anti-HCG activity. However, in the hydatidiform molar patient, fractions 1 through 3 (mol wt greater than 67,000--and containing immunoglobulin) were shown to competitively inhibit complement-dependent antibody lysis on 1 of 4 paternal HLA haplotype (AW32) targets. In 2 of the 3 patients studied, low-molecular-weight fractions (not containing immunoglobulin) significantly inhibited reference anti-HLA binding of antisera directed against only 1 of 4 paternal HLA haplotypes. The immunospecificity of this inhibition was confirmed by criss-cross control assays in which elution fractions obtained from both of these patients were tested for inhibition of lymphocytolysis of both sets of paternal lymphocytes. None of these fractions were immunoreactive to maternal HLA haplotypes. Further analysis of serum from the hydatidiform molar patient revealed that no free complement-fixing antibody against paternal antigens could be found by conventional screening assays in unfractionated patient sera. Three of 4 paternal HLA antigens or non-complement-fixing anti-HLA immunoglobulin was detected in unfractionated pretreatment, treatment, and remission sera of the hydatidiform molar patient. Only in this patient's remission sera was unbound AW32 antigen or non-complement-fixing anti-AW32 antibody detected. These data demonstrate the successful characterization of at least 1 specific antigen fractionated from a tumor-associated immune complex. The implication that some patients with GTN may recognize and react to immunogenic paternal HLA antigens as part of their successful response to therapy for trophoblastic tumor is discussed.

Antigen-Antibody Complex↗
PubMed1983

Interaction of Ia antigen-bearing polymorphonuclear leukocytes and murine splenocytes.

Polymorphonuclear leukocytes (PMN) were induced in the peritoneum of a Balb/c mouse by ip injection of Fusobacterium nucleatum (FN) (greater than 95% PMN). A subpopulation of PMN harvested bore Ia surface antigens and stimulated a mixed lymphocyte reaction (MLR) when cultured with C57B1/6J splenocytes. The reaction was blocked by a short prior incubation of PMN with anti-Ia antibody or PMN cell depletion by the same antibody plus complement. The Ia antigen-bearing PMN were capable of antigenic modulation since incubation of PMN for 24 h rendered the cells incapable of stimulating an MLR. The Ia antigen-bearing PMN produced a soluble material that enhanced the phytohemagglutinin (PHA) response of murine splenocytes and the active material was a product of live cells since the supernatants contained no detectable lactate dehydrogenase activity. The data suggest that murine PMN subpopulations, defined by surface Ia antigen, can modulate mitogenic responses by production of an enhancing factor(s).

Animals↗
PubMed1983

Serial circulating immune complex levels and mitogen responses during progressive tumor growth in WF rats.

Inbred male WF rats were given im injections of one of two antigenically and histologically distinct syngeneic tumor isografts, adenocarcinoma DMH-W 163 or spontaneous renal cell carcinoma SPK. Serum and peripheral blood lymphocytes were harvested from tumor-bearing and normal age-matched controls before and after isograft challenge at weekly intervals. Serial circulating immune complex (CIC) levels were quantitated by polyethylene glycol (PEG) insolubilization. T-cell mitogen responses to phytohemagglutinin (PHA) and concanavalin A (Con A) were followed serially. Tumor growth was measured at least weekly. PEG-CIC values rose early after tumor injection, increased with tumor growth, and declined in some animals just before death. Mitogen response to PHA was significantly decreased in isografted tumor-bearing rats, particularly at later stages of tumor development, compared to normal uninoculated controls. Responses to Con A were variable, and suppression was not always seen in tumor bearers. In animals that did not have progressive tumor growth after isograft injection, PEG-CIC levels did not change and responses to PHA were not suppressed. Patterns of CIC change and responses to PHA were not affected by differences in tumor histology or growth rates. Thus serial CIC levels measured by the PEG assay correlate with tumor growth and precede nonspecific suppression of T-cell mitogenic response in these animal tumor models.

Animals↗
PubMed1983

Circulating immune complex levels in patients with molar pregnancy.

Circulating immune complex levels were measured in patients with molar pregnancy to investigate the relationship between circulating immune complex and trophoblastic tumor burden. When 27 (87%) of 31 patients with molar pregnancy were first seen, circulating immune complex values were in the normal range. Three of the 4 patients with elevated levels had concurrent medical illness. Eighteen patients were followed with serial measurements until gonadotropin remission was achieved and all 18 patients developed increased levels as they entered remission (P less than .001). Circulating immune complex values remained elevated during gonadotropin remission from 6 to 16 weeks and then declined to initial levels. Further investigation should be undertaken to evaluate possible interactions between circulating immune complex and host immune defenses.

Antibody Formation↗
PubMed1982

Effects of supernatants of polymorphonuclear neutrophils recruited by different inflammatory substances on mitogen responses of lymphocytes.

Two different substances, glycogen and thioglycollate, were used to recruit early peritoneal exudate cells (4h). In the acute phase of the inflammatory response the cellular infiltrate is large, and the predominant cell (greater than 95%) is the polymorphonuclear neutrophil. Supernatant had differing effects on lymphocyte responses to the mitogens PHA and LPS, also carried out in serum-free media, depending on recruiting substance and time of culture. While glycogen-recruited PMN supernatant (GPMN-S) always enhanced splenocyte responses to PHA, thioglycollate-recruited cells (TPMN-S) did not produce an enhancing factor until the cells had been in culture for 24 h. Whereas GPMN-S enhanced the splenocyte response to LPS only after 1 or 4 h of culture, TPMN-S failed to have any significant effect. Thymocyte responses to PHA were facilitated by all supernatants. Dilution of the soluble PMN factors resulted in a suppressive effect on splenocyte responses to both PHA and LPS, regardless of whether PMN were recruited by the thioglycollate or glycogen or of the time of cell incubation. These results indicate that PMN-rich cell populations of different types of activity are recruited by glycogen and thioglycollate and that these cells produce factors capable of potentiating, enhancing, or suppressing responses to T- or B-cell mitogens by normal syngeneic lymphocytes.

Animals↗