Zeitschrift für Immunit?tsforschung: Immunobiology最新文献

PGE and PGF release from peritoneal exudate cells was studied in mice after injection with two ß (1–3) glucans, the antitumor active lentinan and the inactive pachyman. 4 days after injection of both polysaccharides, the spontaneous and phagocytosis-induced PGE and PGF release was markedly suppressed. However, only the immunopotentiator lentinan induced peritoneal exudate cells which exhibited a longer lasting diminished PG release. The data suggest that the T cell adjuvant lentinan may potentiate cellular immune responses by reducing synthesis of immune suppressive prostaglandins from peritoneal exudate cells.

Graft-versus-host induced immunosuppression has previously been shown to be accompanied by severe morphological changes in the thymus; furthermore chronic GvH could become acute by grafting a normal syngeneic thymus, suggesting a functional defect in the autologous thymus.

In this work, we monitored the changes occuring in two biologically active thymic stromal fractions during a state of chronic GvH reaction. It was thus observed that a soluble thymic factor (STF), normally found in the reticuloepithelial cells, was lost, and that an insoluble thymic fraction (ITF) found in a double basement membrane surrounding medullary blood vessels, became markedly hypertrophied. These changes are interpreted as being possibly related to the state of immunosuppression by interfering with normal T cell differentiation and traffic through the thymus.

The human serum proteins C-reactive protein (CRP), the 9.5 Sα₁-glycoprotein and C1q show, when tested in the agar gel diffusion under certain buffer conditions, strong precipitin reactions with polysaccharides of the galactan type, indicating that they may have lectin-like recognition sites.

In vitro incubation of human blood cells with iodinated radiographic contrast media (RCM) produced marked effects which were dose-dependent: erythrocytes showed crenation which was reversible; neutrophil leukocytes released the lysosomal enzyme β-glucuronidase; basophil leukocytes released histamine; and platelets released serotonin as well as β-glucuronidase. The release reaction could not be attributed to cell lysis, as demonstrated by the release of the cytoplasmic enzyme lactic dehydrogenase (LDH). In normal human serum, RCM produced activation of the complement system with lysis of cells. This RCM-induced complement activation seemed to occur via the alternate pathway. Stabilizers and cations present in the clinically used RCM solutions did not produce any complement changes.

It is demonstrated that previously described PDF₁-A antigens from pigeon dropping extract contain pigeon IgA. The sera of patients with pigeon breeders' disease contain precipitating antibodies against pigeon IgA, in contrast to the sera of pigeon breeders suffering from unrelated forms of pulmonary dysfunction. The degree of complement consumption by PDF₁-A antigens, pigeon serum, and pigeon IgA turned out to be correlated. No correlation was found between precipitating anti-pigeon IgA antibodies and complement consumption by pigeon IgA in patients' sera.

Two hundred and fifty lymph nodes from 100 patients with lung carcinoma and the same number of regional nodes from 119 patients with gastric ulcer were histologically evaluated by the standardized reporting system of COTTIER et al. Special attention was focused on the immunological reactions in these lymph nodes.

Histologic features suggesting actively functioning humoral and cell-mediated immune reactions were encountered more frequently in the nodes of the control series. The significance of the histologic findings is discussed and it is concluded that there is some degree of derangement of both humoral and cell-mediated immune responses in the lymph nodes draining lung carcinoma. The applicability of the reporting system used is emphasized.

Serum amyloid A protein (SAA) has been shown to be unstable at elevated temperatures. While in agreement with earlier reports, molecular weights of approximately 180,000 daltons were determined by gel filtration at 37°C and below, above 38°C additional AA-antigenic activity was found in the void volume and at the position of approximately 12,000 daltons. The latter polypeptide resembled in size and immunoreactivity SAAL in that it had AA-antigenic determinants exposed at 4°C (unlike SAA). Because the release of SAAL or a similar molecule could not be prevented by the enzyme inhibitor PMSF, a temperature-dependent dissociation of SAA is proposed.

In view of the known occurrence of amyloid following febrile conditions, the change in size and immunoreactivity of AA-antigenic proteins in vitro may indicate that a similar mechanism in vivo is important in the genesis of AA-type amyloidosis.

Permethylation analyses of the spawn material of three toad (Bufo) species allow the conclusion that the serologically determinant group in Bufo bufo spawn is identical with that found in human and hog blood-group A substances (i.e. GalNAc(α1,3) [Fuc(α1,2)] Gal -), and the serologically determinant group in Bufo viridis and Bufo calamita spawn is identical with that found in blood-group H substances (i.e. Fuc(α1,2) Gal -).

The relationship between the mitogenic lectin PNA and other mitogenic and non-mitogenic lectins was investigated. PNA labelled with ¹²⁵I was found to bind equally well to T and B lymphocytes, after neuraminidase treatment, with 3.88 × 10⁶ and 3.73 × 10⁶ binding sites respectively. Only the T cell fraction was stimulated, however, and only after neuraminidase treatment. Preincubation of neuraminidase-treated cells with non-mitogenic lectins and antiserum, which appeared to bind to the same receptor as PNA, enhanced the latter's stimulatory properties.

Capping and co-capping techniques were used to examine the topology of lectin receptors on the lymphocyte surface. The receptor glycoprotein for the mitogenic PNA lectin was found to be distinct from that possessing the Con A and PHA receptors, as well as that possessing the receptor for the non-mitogenic lectin from Helix pomatia.