Brief communication: technical modifications of the human agarose microdroplet leukocyte migration inhibition assay

Computational models in immunological methods: an historical review

The utilization of computational models in immunology dates from the birth of the science. From the description of antibody-antigen binding to the structural models of receptors, models are utilized to bring fundamental understandings of the processes together with laboratory measurements to uncover implications of these data. In this review, an historical view of the role of computational models in the immunology laboratory is presented, and short mathematical descriptions are given of fundamental assays. In addition, the range of current uses of models is explored -- especially as seen through papers which have appeared in the Journal of Immunological Methods from volume 1 (1971/1972) to volume 208 (1997). Each paper which introduced a new mathematical, statistical, or computer simulation model, or introduced an enhancement to an instrument through a model in those volumes is cited and the type of computational model noted.

Monocytes and impaired leukocyte migration inhibitory factor production in head and neck squamous carcinoma

Impaired cell-mediated immunity has been consistently associated with head and neck squamous carcinoma (HNSC). Previous work has implicated monocytes in this impairment. The present study shows that in a subgroup of untreated patients with advanced HNSC, monocytes are responsible for impaired in vitro lymphokine (leukocyte migration inhibitory factor) production. In view of recent studies suggesting interactions between lymphokines and monocytes in the immune response, the present findings may be relevant to future immunotherapeutic approaches.

Expression of A9 antigen and loss of blood group antigens as determinants of survival in patients with head and neck squamous carcinoma

The murine monoclonal antibody (A9), raised to the human squamous cell carcinoma (SCC) cell-line UM-SCC-1, defines a squamous cell antigen associated with aggressive biologic behavior of SCC cell lines in vivo and in vitro. In the present investigation, A9 antigen was detected in tissue sections from 37 consecutive, previously untreated patients with SCC of the head and neck. All tumors were positive for A9 binding, although three distinct patterns (reflecting different intensities of A9 expression) were identified. The intensity of A9 expression was independent of primary tumor site, tumor differentiation, keratinization, or growth pattern. The frequency of high expression (Pattern 1) grew with increasing T class, N class, and tumor stage, and was associated with loss of blood group expression in the tumor and with low levels of lymphocyte infiltration in the tumor. Strong A9 expression had a statistically significant association with low nuclear grade (i.e., tumors with more mature and fewer enlarged nuclei, P = 0.019), low vascular/stromal response (i.e., patchy response rather than continuous, P = 0.014), and impaired in vitro lymphokine production by peripheral blood leukocytes (P = 0.0011). Of greatest interest, however, was the strong association of high A9 expression with shortened disease-free interval (DFI) (P = 0.085) and survival (P = 0.081) relative to patients with weak A9 tumor staining (Patterns 2 and 3). Similarly, the loss of blood group antigen expression was strongly associated with decreased DFI (P = 0.038) and survival (P = 0.062). While neither Pattern 1 A9 expression nor loss of blood group reach statistical significance in prediction of survival, the combination of Pattern 1 A9 expression and loss of blood group expression in primary tumors was significantly associated, both with decreased disease-free interval (P = 0.017) and with decreased overall survival (P = 0.011) (median length of follow-up = 22 months). The length of follow-up (LFU) ranged from 2 to 38 months, with a median LFU of 22 months. While the number of patients (37) is small, the significant association between the expression of these cell-surface markers with relapse and survival indicates that immunohistologic staining of the primary tumor will be an important prognostic indicator useful in identification of individual patients at greatest risk of recurrence or early death from head and neck cancer, independent of tumor size, site, or stage at presentation. These markers may thus provide means of selecting patients who should receive adjuvant therapy and more intensive monitoring for the early detection of recurrent disease.

Cell-mediated immune responses to artificial food additives in chronic urticaria

In some cases of chronic urticaria it is suspected that food additives such as tartrazine and sodium benzoate or salicylates may play a role in the pathogenesis of the condition. Since, at times, chronic urticaria may appear histologically similar to a mild cell-mediated immune response, the release of the T cell-derived lymphokine leucocyte inhibitory factor (LIF), in response to incubation with these additives and with acetylsalicylic acid (ASA), was measured in vitro using cells from normal controls, from patients with chronic urticaria with or without clinically associated additive sensitivity and from patients with asthma with or without associated ASA sensitivity. It was found that significant production of LIF occurred in response to tartrazine and sodium benzoate in those individuals with chronic additive induced urticaria. In addition, tartrazine caused LIF release from mononuclear cells of ASA-sensitive asthmatics. These results may indicate a possible role for additive-induced cell-mediated immune responses in the pathogenesis of some cases of chronic urticaria and suggest a potential diagnostic test for this condition.

Radiation leukemia virus-transformed immunocompetent T cells. II. Antigen-induced macrophage migration inhibition factor and leukocyte migration inhibition factor production

OVA-specific T cells were immortalized by infection with radiation leukemia virus (RadLV). Some clones derived from such population were shown to exhibit helper activity. We then tested clones without such function and found among them some that secreted macrophage migration inhibition factor (MIF) and leukocyte migration inhibition factor (LIF) upon exposure to the antigen in vitro. The lymphokine-producing clones, which were Thy-1+, Ly-1+ and Ly-2-, did not secrete MIF and LIF constitutively. Like other antigen-specific T cells, the immortalized clones could not be stimulated by free soluble antigen but required macrophages for presentation and for triggering the lymphokine production. The antigen-activated clones exclusively produced MIF and LIF, but not interleukin 2 or colony-stimulating factor. They neither provided helper activity nor induced delayed-type hypersensitivity. The data suggest that the T-cell clones carry the antigen receptors and that their antigen-inducible biological function is restricted to the migration inhibitory factor production.

Leukocyte migration inhibition in bacillus Calmette-Guérin vaccinated healthy adults and in tuberculosis assayed by a rapid photoelectric procedure

A sensitive photoelectric method was used for reading migrations of human peripheral blood leukocytes from agarose microdroplets. Its rapidity enabled the use of a wide range (12 logs) of in vitro concentrations of antigen. Inhibition of migration of leukocytes (LMI) of healthy subjects having had BCG vaccination in childhood was found to occur in two zones of PPD concentrations, one high, from 10(-1) to 1000 micrograms/ml with a peak at 100 micrograms/ml, and one low, from 10(-8) to 10(-2) micrograms/ml. While three-fifths of subjects showed high zone LMI, in one-fifth it was bizonal and in another fifth observed only in the low zone. In patients with active pulmonary tuberculosis LMI, prior to all treatment, was reduced, absent, or replaced by enhanced migration, particularly in the low zone or in both zones. One and a half to four months after treatment LMI was found to be bizonal, enhanced migration having disappeared. These observations suggest the participation of two cell populations with widely different sensitivity to PPD in LMI in tuberculous and BCG vaccinated subjects and the presence of migration stimulatory lymphokine(s) during active tuberculosis.

Cytotoxic and migration inhibitory effects of bisphosphonates on macrophages

Two in vitro model systems were developed to facilitate investigation of the mechanisms by which bisphosphonates block bone resorption. These systems assess the cytotoxic and the migration inhibitory activities of bisphosphonates using mouse peritoneal macrophages as osteoclast surrogates. Several bisphosphonates, 3-amino-1-hydroxypropylidene-1,1-bisphosphonate (AHPrBP), dichloromethylene bisphosphonate (Cl2MBP), 1-hydroxyethylidene-1,1-bisphosphonate (HEBP), 1-hydroxybutylidene-1,1-bisphosphonate (HBBP), 1-hydroxyhexylidene-1,1-bisphosphonate (HHBP), and 1-hydroxyoctylidene-1,1-bisphosphonate (HOBP), possess the same relative activities in these systems as they do in bone resorption systems. Calcium ion replacement studies using these systems demonstrated that bisphosphonates do not derive all their activity from sequestration of calcium ions from cells by chelation. Whereas calcium ion replacement abrogated the activity of EDTA, a nonbisphosphonate calcium chelator active in both systems, it failed to abrogate either the cytotoxic or the migration inhibitory effects of the bisphosphonates tested. Calcium ion replacement increased the migration inhibitory activity of all the bisphosphonates tested. Further, calcium ion replacement increased the cytotoxicity of HHBP and HOBP; however, it decreased the cytotoxicity of HEBP, HBBP, AHPrBP, and Cl2MBP.

Beta endorphin enhances in vitro lymphokine production in patients with squamous carcinoma of the head and neck

Recent studies of the effects of endorphins and other neuropeptides on immune mechanisms suggest that immune reactive cells have specific opioid-like and nonopioid endorphin receptors, and indicate that neuropeptides may participate in regulating in vivo immune functions. Earlier demonstrations of impaired cellular immunity and impaired lymphokine production in patients with cancer of the head and neck prompted an investigation of the in vitro effects of beta-endorphin on the production of leukocyte migration inhibitory factor (LIF) in 29 patients with head and neck cancer and in 45 normal subjects. LIF production in response to phytohemagglutinin was significantly less in the cancer patients compared to normal subjects (p less than .001). beta-endorphin significantly enhanced LIF production in the cancer patients (p = .01) to levels that did not differ significantly from normal levels. A correlation of levels of lymphocyte subpopulations in the cancer patients suggested that enhancement of lymphokine production by beta-endorphin was related to levels of T8 (suppressor/cytotoxic) cells. The results confirm earlier demonstrations of impaired lymphokine production in patients with head and neck cancer and indicate that beta-endorphin can modulate in vitro lymphokine responses in such patients. These findings suggest that neuroendocrine peptides may play an important role in regulating immune function. Further study of the role of neuropeptides in the immune response should provide additional insight into the characterization of cellular immune dysfunction associated with head and neck cancer and should lead to the development of innovative immunotherapeutic treatment strategies.

Leukocyte migration inhibition in recurrent aphthous ulceration

Leukocyte inhibitory factor (LIF) production in response to streptococcal antigens and oral mucosa was examined as a possible pathogenic mechanism in recurrent aphthous ulceration (RAU). Mononuclear cells from RAU patients and controls were stimulated with antigens prepared from two species of streptococci and from oral mucosa. Candida albicans and foreskin were tested as control antigens. There were some statistically significant differences in leukocyte migration inhibition between patients and controls with some concentrations of Streptococcus sanguis (ATCC 10556) and C. albicans, and a trend toward low migration indices with oral mucosa. However, the roughly equal numbers of patients and controls responding positively to each antigen and the large background variation suggest a lack of biological significance. LIF production did not increase consistently in the early stages and did not correlate with ulcer development in patients studied sequentially. We conclude that LIF production (at least in response to the antigens tested) plays no pathogenic role in RAU. Our data do not support the hypothesis that a specific cell-mediated sensitivity to streptococcal antigens is involved in RAU.

Production of leukocyte migration inhibitory factor (LIF) in human lymphocyte subsets exposed to polyclonal activators

Lymphocyte subsets separated on the basis of nylon-wool adherence and E and EA rosetting, and characterized for the presence of esterase-positive phagocytic cells were investigated for production of leukocyte migration inhibitory factor (LIF) in response to polyclonal T- and B-cell activators, PHA, ConA, PWM, and Epstein-Barr virus (EBV). In the nylon-passed population only the high avidity E+EA+ cells responded to ConA, PHA-induced LIF production in all E-rosetting subsets. The nylon-adherent E+ subset, which contains activated T cells, produced LIF spontaneously. B cells produced LIF when exposed to PWM or uv-inactivated EBV. In accordance with the known T-cell dependence of PWM activation, LIF was detected only in supernatants of reconstituted populations containing both B and T cells. In contrast, uv-inactivated EBV, devoid of transforming potential, elicited LIF production in the pure B-cell population. LIF production in response to polyclonal activators seemed to be independent of accessory cells since reconstitution with autologous macrophages or semipurified monokine, high-molecular-weight Interleukin 1 (IL-1), did not alter the results.

An ELISA method for quantitation of macrophage migration from agarose microdroplets

A method is described for quantitating the biological activity of macrophage migration inhibitory factor (MIF) based on the detection of macrophages migrating from agarose droplets. The migration is determined with polyclonal anti-macrophage antibodies in an ELISA assay. The numbers of macrophages thus detected correlate well with the migration as measured by a capillary tube assay for MIF.

A rapid photoelectric method for reading cell migration from agarose microdroplets

A rapid photoelectric method for reading cell migration from agarose microdroplets is described. Practically instantaneous, the method eliminates drawing and planimetry and makes feasible the use of a wide range of antigen concentrations. The results obtained are similar to those obtained by planimetry, but the photoelectric method is more sensitive. Enhancement of migration as well as inhibition were significantly demonstrated by this method. Migration inhibition of immune mouse spleen cells was found to be bizonal, with 2 peaks, one at very low antigen concentrations (10(-3) microgram/ml ovalbumin) and one at 10 microgram/ml.

Lymphokine production in T-lymphocyte subsets defined by active E-rosette formation

Human T-cell subsets, defined by active E rosette formation, were examined for their ability to produce leucocyte migration inhibitory factor (LIF) in response to mitogen or specific antigen. It was determined that T cells enriched for active rosette-forming (A+) cells produced LIF in response to concanavalin A, whereas T cells depleted of active rosette-forming (A-) cells did not. Similarly, A+ cells from a tuberculin-sensitive donor produced LIF in response to tuberculin purified protein derivative, whereas A- cells from the same donor failed to produce the mediator. Thus, T-cell production of LIF in humans appears to be restricted to those T cells capable of active rosette formation.

Immunology of human gastric cancer: a preliminary report

The immunological spectrum in fifteen patients with gastric cancer is presented. Patients were divided in three groups. Those with nonadvanced cancer, those with advanced but resectable lesions and those with advanced but nonresectable tumors. Preoperatively, elevated levels of circulating immune complexes (CIC) associated with hyporesponsiveness to phytohemagglutinin (PHA) and in mixed lymphocyte culture (MLC) as well as a positive leukocyte inhibitory serum factor (LIF-S) were found in nearly half of the patients. Inhibitory or enhancing autologous serum factors were detected. Postoperatively, immunologic parameters return to normal in patients with nonadvanced cancer, while in advanced cancer, antibody and cell-mediated immune response remained altered, with some changes associated with chemotherapy. These findings are probably related with the presence or absence of tumor and offer a distinct approach in evaluating the immunologic response of a tumor-bearing patient.

The effects of some antirheumatic drugs on an in vitro model of human polymorphonuclear leucocyte chemokinesis

1 A rapid, reproducible in vitro assay for studying the chemokinetic movement of human polymorphonuclear leucocytes (PMNs) is described. Two synthetic peptides, formyl methionyl-leucyl-phenylalanine (FMLP) and formyl methionyl-phenylalanine (FMP), were used as a standard chemokinesins. 2 Maximal chemokinetic movement was observed with peptide concentrations of 2.5 nM (FMLP) and 100 muM (FMP). EC50 values of 650.0 +/- 60.0 pM and 27.0 +/- 3.5 muM respectively are similar to those reported for chemotactic activity of the peptides in micropore filter assays. 3 The PMN chemokinetic response to FMLP was enhanced by histamine (100 nM) and vitamin C (2.5 muM). 4 Human serum albumin was shown to induce chemokinesis but to antagonize the response to FMLP in a dose-related fashion. Fibrinogen similarly antagonized the cell response to peptide. 5 Levamisole (250 nM to 2.5 muM) significantly potentiated the chemokinetic responses to FMLP and FMP in a dose-related manner. The chemokinetic response to FMLP was unaffected by D-penicillamine (250 muM to 10 mM) while alclofenac (500 muM to 1 mM), salicylic acid (250 muM to 10 mM) and indomethacin (100 muM to 1 mM) caused dose-related inhibition.

Correlation between agarose microdroplet and capillary tube procedures as assays for migration inhibition of target cells

We have compared the capillary tube assay for migration inhibition studies with our modification of the agarose microdroplet technique, using several sources of factors with inhibitory activity (lymphokines, bacterial factors) and a variety of cell types (inflammatory exudate cells, tumor cells). In all circumstances both procedures gave quantitatively similar results, and high statistical correlation was found. These results suggest that the two procedures are measuring similar properties, and in any case may be used interchangeably as assays.