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Background and Objectives Dendritic cells (DCs) are promising adjuvants for clinical immunotherapy, but they are scantily distributed. Therefore, numerous in vitro methods have been developed to expand these cells while maintaining their normal functions. Current culture systems generally require the use of fetal bovine serum (FBS)-supplemented media in order to attain DCs with high immunostimulatory activity. However, the presence of exogenous animal proteins sets limits for their use in clinical trials. The purpose of this study was to establish a simple, efficient and FBS-free method for the generation of human DCs for clinical application. Materials and Methods We compared monocyte-derived DCs generated in a standard FBS-supplemented medium vs. DCs generated in an autologous plasma (AutoPl)-supplemented medium, with regard to their yield, function and longevity. Peripheral blood monocytes were isolated from buffy coats by two consecutive 2-h adherence steps in tissue culture flasks. The adherent cells were differentiated into DCs within 2 weeks by adding granulocyte–macrophage colony-stimulating factor (GM–CSF), interleukin-4 (IL-4), c-kit ligand and tumour necrosis factor-α (TNF-α). Every 2–3 days, the cells in suspension were analysed for their immunophenotype and apoptosis rate by flow cytometry. Their function was demonstrated by their allostimulatory and migratory capacity, as well as by their proteolytic activity. Results We show that more than 30 × 106 DCs can be achieved per unit of buffy coat using either AutoPl- or FBS-supplemented media. The purity of the DCs was 53·4% and 65% (P > 0·05) in AutoPl- and FBS-based medium, respectively. DCs grown in AutoPl media showed a CD80high CD83+ CD86high CD14neg HLA-DR+ CD1aneg phenotype, while FBS-generated DCs exhibited a CD80high CD83+ CD86high... [ABSTRACT FROM AUTHOR]

Alveolar macrophages of some species have been found to react specifically with several xenogeneic red cells. The reaction, which is detected by spontaneous rosette formation, has two characteristic features. (a) The spontaneous rosettes do not produce, in the absence of exogenous serum proteins, any demonstrable cell-hound immunoglobulins, or divalent ions. These properties distinguish this newly described phenomenon from those known macro- phage reactions mediated by cytophilic antibodies or by complement. (b) In contrast to the non-specific reactions of macrophages with inert particles, the reaction described here has distinct specificity and appears to utilize a membrane- associated 'receptor'-type mechanism. This receptor is not blocked by anti-globulin but is suppressed by anti-macrophage antibodies. Except for having a wider range of specificity, in some of its characteristics the receptor on macrophages appears to be analogous to the T-cell receptor for xenogeneic red cells. It. is suggested that these receptors may play a role in macrophage-T cell co-operation. and in the immune response in general. [ABSTRACT FROM AUTHOR]

Physicochemical parameters of antigen-antibody reactions in various blood group systems were studied by means of a modified Polybrene technique, performed in a continuous flow system. Antibody-dependent aggregates were deaggregated by exposure to progressively increasing temperature. The temperature at which one-half of the aggregates dissociate (T 50 per cent) has been found to depend upon thermal characteristics as well as the concentration of the antibodies involved. In accordance with the results of a kinetic study of this deaggregation phenomenon, a plot of the logarithm of the antibody concentration versus the reciprocal of T 50 per cent (in absolute temperature units) was found to produce a straight line. Such plots were obtained for different examples of anti-Rh0, -M, -I, and single examples of anti-rh', -hr', -A, -S, -Fya, -Jka and -Kell antibodies. The results indicate that each system possesses a characteristic slope, and intercept with a position in a predictable thermal area. The slopes were interpreted in terms of the activation energy required for breaking the antigen-antibody bonds. This approach provides a means by which thermal characteristics of antigen-antibody systems can be determined independently of antibody concentration. The approach allows the differentiation of serologically distinct antigen-antibody systems based upon information extracted from the dissociation behaviour of aggregated red cells. [ABSTRACT FROM AUTHOR]

This article presents the study of canine erythrocyte antibodies. An adaptation of the Polybrene technique for typing of canine erythrocytes is reported in this paper. Dog whole blood was anticoagulated with acid-citrate-dextrose in a proportion of 1:9 The samples were stored at 40, and used within 10 days. Manual typing and titrations were performed. Adaptation of this technique to canine blood study required two modifications: 15 per cent bovine serum albumin was substituted for homologous normal serum; the concentration of Polybrene was reduced to 0.033 mg/ml. Results demonstrated that the Polybrene technique is from 12.5 (anti-A) to 3200-fold (anti-He) more sensitive than the manual technique.

Cold insolubility of a serum IgA cryoimmunoglobulin was found to be inhibited by the addition of 1.5 mM sodium decanedicarboxylate in vitro. The patient with the cryoglobulin had advanced multiple myeloma complicated by severe hyperviscosity that caused lethargy and episodic loss of consciousness. Decanedicarboxylic acid administered orally resulted in transient relief of symptoms and the loss of cryoprecipitability of the paraprotein. Further in vitro studies revealed that sodium salts of long-chain monocarboxylic acids with a minimum of eight carbons, and dicarboxylic acids with a minimum of 12 carbons inhibited cryoprecipitation. Salts of short-chain carboxylic acids, by contrast, enhanced cryoprecipitation. Sodium phenolate and sodium salts of benzoic acid, 2,4-DNP, phenylpropionic acid, and salicylic acid were also inhibitory. These latter compounds, which have a ring structure, did not cause precipitation at any concentration. It was demonstrated that the presence of a free carboxylic group was required for these activities; conversion of carboxylic acid to amide resulted in the loss of both the inhibitory and cryoprecipitation-enhancing effects. Normal plasma, or plasma from five other patients who had IgG, IgM, or mixed-type cryoglobulinemia, were not affected by any of these compounds. It is suggested that in selected cases of hyperviscosity syndrome associated with cryoglobulinemia, some of these compounds, especially monocarboxylic acids with appropriate chain lengths, or those with a ring structure, may have therapeutic applications.