Helper and suppressor functions of human mononuclear cells depleted of antigen-binding T8+ cells

We have utilized the antigen-binding function of a subset of T8+ cells to remove these cells in vitro from human peripheral blood mononuclear cells. This was carried out by treating the cells with streptococcal antigen (SA), monoclonal anti-SA antibody and complement. The concentration of SA binding to T8+ cells differs with the HLA-DR type of the cells: 1 ng SA binds to DRw6+ cells and elicits T helper activity, whereas 1000 ng SA elicits T suppressor activity, in an assay for antibody-forming cells. After depletion of the antigen-binding cells by the SA-specific complement-dependent killing technique, the helper function of the DRw6+ cells was lost but suppression was elicited not only by 1000 ng but also by 1 ng SA. Similarly, DRw6- cells which bind 1000 ng SA to elicit helper activity and 1 ng to elicit suppression, when depleted of the SA-binding cells, resulted in loss of helper activity but again, suppression could be elicited by both 1000 and 1 ng SA. We suggest that treatment of mononuclear cells with antigen, the specific antibody and complement removes the T8+ antigen-binding cells which present antigen to T helper cells and results in the loss of helper function. Suppressor function is however, not only retained with the original concentration of SA but also expressed with that required to elicit helper function in the untreated cells. These findings are consistent with our hypothesis that the antigen-binding and presenting T8+ cells also function as contrasuppressor cells. Thus, the T8+ subset of cells have a dual function, to present antigen and to activate T helper cell function, and to prevent suppressor cells from inhibiting the helper cells.

Separation and characterization of a subset of human T8+ cells which function as antigen-presenting and contrasuppressor cells

The lectin Vicia villosa (VV) binds preferentially a subset of T cells. Separated VV-adherent cells (AC) do not generate helper function alone, but when added to VV-non-adherent cells (NAC), they can present streptococcal antigen (SA) and induce helper function as effectively as monocytes, at a ratio of 1 VV-AC to 4 VV-NAC. Further separation into a T8+ subset of VV-AC and reconstitution with T4+ helper cells (HC) has established that the T8+ VV-AC induces T4+ cells to helper activity. However, in addition to antigen presentation, the T8+ subset of VV-AC has a contrasuppressor function, for it can prevent T8+ suppressor cells from inhibiting T4+ HC function. The results suggest that a T8+ subset can present antigen to T4+ HC, activate helper function and prevent suppression. The T8+ VV-AC may have considerable biological significance in its dual function of countering the dominant suppressor activity and presenting antigen to induce helper activity.

Detection of cross-reacting murine I-J like determinants on a human subset of T8+ antigen binding, presenting and contrasuppressor cells

Murine I-J gene products have been found in T suppressor cells (SC) and factors, macrophages and contrasuppressor cells (CSC). However, a human counterpart of the murine I-J has not been reported. As there is strong evidence that some murine anti-Ia antisera cross-react with human Ia antigens, the possibility was tested that mouse anti-I-J antibodies might cross-react with corresponding human class II determinants. Indeed, this revealed that three anti-I-J monoclonal antibodies (MoAb) and two antisera tested react with human mononuclear cells and that a significantly greater proportion of T8+ than T4+ cells or monocytes (Mo) react with the I-J antibodies. This was corroborated by autoradiography with significant inhibition of 125I-SA (streptococcal antigen) binding to T8+ cells but not to Mo by the MoAb or antisera to murine I-J. Functional reconstitution experiments of T4+ helper cells with the SA binding and presenting T8+ Vicia villosa adherent cells (VV-AC) and assessment of specific antibody forming cells to SA suggest that the antigen presenting function of this T8+ subset can be significantly inhibited by killing with the MoAb to I-J and complement. Furthermore, the subset of T8+ VV-AC also functions as CSC, for killing with MoAb to I-J and complement significantly inhibited the contrasuppressor function. This is consistent with the presence of I-J gene products in murine CSC. However, similar treatment of T8+ VV-NAC (non-adherent cells) or monocytes (Mo) failed to affect the suppressor or accessory helper function of these cells, respectively. Phenotypic characterization, inhibition of 125I-SA binding and reconstitution experiments for helper and suppressor functions, suggest that a subset of T8+ antigen binding, presenting and CSC may express determinants cross-reacting with murine I-J molecules.

Sequential development of helper and suppressor functions, antibody titers and functional avidities to a streptococcal antigen in rhesus monkeys

Sequential development of antibody titer, functional avidity, helper and suppressor activities were investigated in rhesus monkeys. These were immunized with a single dose of 0.1 microgram to 10 mg of a streptococcal protein antigen (SA) in aluminium hydroxide. The IgG antibody titers followed the classical pattern first established in mice, of high-dose and low-dose tolerance with intermediate doses of immunity. This was correlated with a similar pattern of functional avidity of IgG antibodies, as measured by a dissociation assay. Helper and suppressor functions were assayed in parallel by inducing the corresponding factors from monkey lymphocytes in Marbrook flasks and testing the factors which cross the species barrier in cooperative cultures with CBA mouse spleen B cells. A progressive modulation of helper and suppressor activities was elicited by the increasing doses of SA, during the initial 28 days after immunization. Thus, dominant suppressor with minimal helper activity, IgG antibody titer and functional avidity were elicited by 0.1 microgram SA. However, 1 or 10 micrograms SA induced dominant helper with minimal or transient suppressor activity and high IgG antibody titers and functional avidity. Somewhat intermediate responses were elicited by 100 micrograms SA, but 1 mg and especially 10 mg SA induced dominant suppressor and minimal helper activity, with low IgG antibody titers and functional avidities. When the immune response was established, about 28 days after immunization, the intermediate dose of SA elicited IgG antibodies with high titer and functional avidity, high T cell helper but low suppressor activities. In contrast, both high- and low-dose SA induced partial tolerance, with low IgG antibody titer, functional avidity and T cell helper activity. These studies suggest cyclical development of helper and suppressor functions during the 4 weeks after immunization. The emergence of a dominant helper or suppressor function is antigen dose dependent.

A comparative trial of intra-nasal beclomethasone dipropionate and sodium cromoglycate in patients with chronic perennial rhinitis

A double-blind crossover study has compared intra-nasal sodium cromoglycate (SCG) with beclomethasone dipropionate (BDP), and both drugs with placebo, in fifty-two chronic perennial rhinitis patients. BDP was significantly more effective in relieving symptoms than SCG (76.9% and 50% of the patients improved respectively, P < 0.01). Both drugs were more active than placebos but while BDP was very clearly more effective (P < 0.0005) SCG was only marginally better than its placebo (P < 0.05, Fisher; P = 0.068, chi 2). BDP was selected by 56% of the patients as the best agent for continuing therapy at the end of the trial. By contrast SCG was preferred by the same number of patients as chose the two placebos (11.5%).

Effects of craniofacial structures on mouse palatal closure in vitro

Heads of Swiss-Webster mouse fetuses of four ages spanning days 12-13 of gestation, were partially dissected by removing the brain (B), tongue (T) and mandible (M) alone or in combination (BT, BM, BTM). Preparations were suspended in a gassed, circulating culture system such that palatal closure must take place against gravity. Closure occurred earlier than in vivo and required the posterior half of the mandible be intact and the tongue removed.

Automated enzymic determination of ethanol in blood, serum, and urine with a miniature centrifugal analyzer

We describe an automated spectrophotometric reaction-rate method for determination of ethanol in serum and urine with a miniature centrifugal analyzer. The theanol is selectively oxidized in the presence of alcochol dehydrogenase and NAD+ to form NADH, which is measured by the rate of change of its absorbance. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer-generated working curve based on aqueous ethanol standards. Blood, serum, or urine specimens need not be deproteinized. The method permits duplicate analysis of at least 30 samples per hour. Coefficients of variation and relative errors are about 2-3% for ethanol concentrations of 0.3-3.0 mug per 2 mul of sample. Analytical recovery of ethanol added to serum is 92-103% (average, 98.5%). Comparisons with distillation-oxidation, gas-chromatographic, and conventional enzymic procedures give satisfactory agreement.

Automated enzymic determination of ethanol in blood, serum, and urine with a miniature centrifugal analyzer

We describe an automated spectrophotometric reaction-rate method for determination of ethanol in serum and urine with a miniature centrifugal analyzer. The theanol is selectively oxidized in the presence of alcochol dehydrogenase and NAD+ to form NADH, which is measured by the rate of change of its absorbance. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer-generated working curve based on aqueous ethanol standards. Blood, serum, or urine specimens need not be deproteinized. The method permits duplicate analysis of at least 30 samples per hour. Coefficients of variation and relative errors are about 2-3% for ethanol concentrations of 0.3-3.0 mug per 2 mul of sample. Analytical recovery of ethanol added to serum is 92-103% (average, 98.5%). Comparisons with distillation-oxidation, gas-chromatographic, and conventional enzymic procedures give satisfactory agreement.

A new in vitro system for studying secondary palate development

An in vitro system was devised which supports palate development in partially dissected embryonic mouse heads. The heads were suspended in the culture chamber so that they were not held in a fixed orientation and were constantly surrounded with a fluid medium. Under these circumstances the developing palate must effect closure without the aid of gravitational forces. The culture medium was constantly circulated, gassed with 95% O2, 5% CO2 using hollow fiber gas permeation devices, and kept at 34 degrees C. Swiss-Webster mouse embryos of 12 days 12-18 h (ca. 48 h prior to expected in vivo closure) or 13 days 8-14 h (ca. 24 h prior to closure) were used to test the ability of the system to support palatal development. Embryonic heads were dissected in one of two ways before culture: brain and tongue removed, or brain, tongue and mandible removed. After 24 h in culture, preparations of either age with only the brain and tongue removed had made substantially greater progress than their counterparts with the brain, tongue and mandible removed. With only the brain and tongue removed, the palatal shelves were contacting, adhered or fused in 67% of the older embryos of the same age cultured with the brain, tongue and mandible removed had shelves that were not fully elevated and still separated by a moderate gap. Thus for maximal progress in the present system, the oral cavity must be intact except for the tongue.

A new in vitro system for studying secondary palate development

An in vitro system was devised which supports palate development in partially dissected embryonic mouse heads. The heads were suspended in the culture chamber so that they were not held in a fixed orientation and were constantly surrounded with a fluid medium. Under these circumstances the developing palate must effect closure without the aid of gravitational forces. The culture medium was constantly circulated, gassed with 95% O2, 5% CO2 using hollow fiber gas permeation devices, and kept at 34°C. Swiss-Webster mouse embryos of 12 days 12–18 h (ca. 48 h prior to expected in vivo closure) or 13 days 8–14 h (ca. 24 h prior to closure) were used to test the ability of the system to support palatal development. Embryonic heads were dissected in one of two ways before culture: brain and tongue removed, or brain, tongue and mandible removed. After 24 h in culture, preparations of either age with only the brain and tongue removed had made substantially greater progress than their counterparts with the brain, tongue and mandible removed. With only the brain and tongue removed, the palatal shelves were contacting, adhered or fused in 67 % of the older embryos, whereas most of the embryos of the same age cultured with the brain, tongue and mandible removed had shelves that were not fully elevated and still separated by a moderate gap. Thus for maximal progress in the present system, the oral cavity must be intact except for the tongue.

A Versatile Minidisc Module for a Centrifugal Analyzer

We have developed a centrifugal minidisc module, which extends the versatility of the centrifugal analyzer system with respect to radiation sources, wavelength selectors, radiation detectors, and the analysis performed by the system. The motor, brake, power supply, and control circuitry for the sample/reagent minidisc unit has been repackaged in a compact module, which is easily attached to an optical reference base. Appropriate wavelength selectors, source, and detector modules can then be easily aligned with the minidisc module. Use of a programmable ultraviolet—visible monochromator can provide the automated wavelength selection necessary for application to simultaneous multi-type analyses. Design features of the centrifugal minidisc module are presented, and its versatility is illustrated.

Incorporation of a High-Speed Decimal Data Processor into a Centrifugal Analyzer

We incorporated a new high-speed data processor into a centrifugal analyzer system. The data processor is compact and inexpensive, yet it is capable of performing the essential control and data-manipulation functions that are usually performed by a minicomputer. The ease with which the system can be programmed to perform a typical analytical procedure is illustrated. The interaction of system components during the analysis is described, with emphasis on the role of the processor. Analytical results are presented.

A Centrifugal Analyzer with a New All-Digital Measurement System

An accurate, all-digital measurement system has been developed for use in a centrifugal analyzer system. The output of the radiation detector is converted directly to a digital count by a new type of charge-to-count converter. The converter is characterized by exceptional linearity and stability, and has a wide dynamic range. A gating and counting unit integrates the output of the charge-to-count converter and simultaneously measures the period of integration. The integration effectively discriminates against noise and allows an optimum amount of information to be extracted from the signal during the measurement period. Measurement of the integration period reduces requirements for synchronization and control devices, thus simplifying overall analyzer design. Control and data manipulation functions are performed by a minicomputer. The programs were written in OS/8 FORTRAN. The basic measurement principles of the new system and test results are described.