The presence of blood group and lymphocyte antigens on porcine granulocytes

Suspensions of highly viable (< 95 %) granulocytes minimally contaminated by other cell types were isolated from the peripheral blood of pigs by a single centrifu-gation with low molecular weight dextran and after preferential lysis of erythrocytes by hypotonic shock. A complement-dependent cytotoxic test showed the presence of antigens of the SLA major histocompatibility complex, the SLB leucocyte system and the A and E blood group systems on the granulocytes. Some SLA typing reagents against class I (SD) antigens did not react with granulocytes, however, or yielded dubious reactions. The findings showed that the reactivity of SLA sera resembles the reactivity of human HLA sera. The results also show that compatibility in the SLA, SLB, A and E systems will have to be taken into account when preparing alloimmune sera for the determination of granulocyte-specific antigens of pigs.     

Effect of a streptococcal allergen on the rosette-forming capacity of the T-lymphocytes in erysipelas patients

The reaction of antigen-dependent E-rosette formation with the hemolytic streptococcal antigen in erysipelas patients is indicative of the ambiguous role of the specific immunological transformation of the body in respect of the infective agent antigens in different clinical forms of the disease and is of prognostic importance as regards the chronic transformation of the infectious process and the development of the relapses of the disease.     

Determination of antibodies against ribosomes and various cell wall components and detection of circulating antigens of group A Streptococcus in patients with erysipelas

The level of antibodies to the ribosomes, polysaccharide A and peptidoglycan of group A streptococcus in the blood of patients with primary, secondary, and often relapsing erysipelas was studied by means of the enzyme immunoassay with the use of the sandwich techniques. For control, the sera of healthy donors were used. In the sera obtained from all groups of erysipelas patients a significant rise in the levels of antibodies to ribosomes and peptidoglycan in comparison with the controls was revealed. An increase in the level of antibodies to polysaccharide A was revealed only in patients with frequently relapsing and secondary erysipelas. Depending on the clinical form and the duration of the disease, polysaccharide A was detected in 32-51.9% of erysipelas patients and protein-ribosomal antigen was detected in 28.6-51.9% of such patients.     

Serum antibodies to group A streptococcal extracellular and cell-associated antigens in Egyptians with post-streptococcal diseases

We investigated serum antibodies to a comprehensive array of group A streptococcal antigens and superantigens in Egyptian subjects. Antibodies to Streptococcus pyogenes cell-associated proteins and to proteins released by rapidly dividing S. pyogenes were compared in four patient groups with different post-streptococcal diseases and in healthy controls. Enzyme-linked immunosorbent assays showed that total Ig and IgG to extracellular antigens were significantly higher in patients with acute rheumatic fever (ARF) compared to healthy controls, but no differences were found in either total Ig or IgG titres to cell-associated proteins between any of the groups. Western blotting showed that multiple extracellular and cell-associated antigens, covering a wide range of molecular masses, were recognised by all sera, including healthy controls. No evidence was obtained for putative dominant antigens associated with any disease group, although a low molecular mass cell-associated protein (approximately 4 kDa) was clearly recognised by two-thirds of subjects irrespective of disease status. These findings demonstrate that raised serum Ig and IgG titres to extracellular, but not cell-associated, S. pyogenes antigens are a feature of ARF in this population, and suggest that multiple S. pyogenes antigens contribute to this response.     

Epitopes of group A streptococcal M protein shared with antigens of articular cartilage and synovium

Rabbit antisera evoked by purified pepsin-extracted group A streptococcal M proteins were screened for the presence of joint cross-reactive antibodies by indirect immunofluorescence using thin sections of mouse knee joints. Pep M1, M5, and M18 antisera contained antibodies that cross-reacted with chondrocytes, cartilage, and synovium. Immunofluorescence inhibition assays showed that some of the joint cross-reactive epitopes were shared among the three heterologous serotypes of M protein. The pep M5 joint cross-reactive epitopes were localized to three different synthetic peptides of the C-terminal region of pep M5. Immunoblot analyses showed that the M5 joint cross-reactive antibodies recognized two proteins of human synovium and cartilage of molecular mass 56 and 58 kDa. The cross-reactive antibodies binding to the 56-kDa protein were inhibited by purified vimentin in immunoblot inhibition experiments. M protein-specific antibodies from patients with acute rheumatic fever were also shown to cross-react with joint tissue in a pattern similar to the rabbit antisera. Rabbit and human M protein-specific antibodies that were bound to articular cartilage activated significant levels of complement when compared to control serum, suggesting that M protein joint cross-reactive antibodies could potentially be involved in the pathogenesis of ARF and arthritis.     

The presence of blood group A-active glycolipids in cancer tissues from blood group O patients

Glycolipids were isolated from human gastric cancer tissues and normal mucosae. Sulfogalactosylceramide, ganglioside and neutral glycolipid fractions were separated by DEAE-Sephadex and silica gel column chromatography. Sulfogalactosylceramide contents were higher in the cancer tissues than in the normal mucosae. Ganglioside contents showed considerable variations but in the cancer tissues in mole percentage of ganglioside GM3 was higher than in the normal mucosae. The cancer tissues contained more neutral glycolipids than normal tissues. Glycolipids of lacto-series, including fucolipids, were markedly increased in the cancer tissues. Blood group A-active glycolipids were found in the cancer tissues from two patients with blood group O but not found in the uninvolved tissue associated with the cancer tissue.     

The occurrence of the feline A blood group antigen on lymphocytes

Sera from 300 cats were tested for the presence of anti-lymphocytic antibodies. One hundred and nineteen sera showed some activity with the majority (79) reacting only with lymphocytes from blood group A cats. Absorption of two such sera with A, AB and B erythrocytes and absorption of AB system reagents with lymphocytes from A and B blood group cats demonstrated that the A antigen is expressed on both erythrocytes and lymphocytes. Blood group and lymphocyte typing tests of foetuses indicated that the A antigen is present on these tissues as early as 46 days gestation. The erythrocytic B antigen could not be demonstrated on lymphocytes although a single antiserum, which reacted against lymphocytes from group B cats, was found. Several sera containing anti-lymphocytic antibodies which were not related to the AB type were also detected.     

The occurrence of the feline A blood group antigen on lymphocytes

Sera from 300 cats were tested for the presence of anti-lymphocytic antibodies. One hundred and nineteen sera showed some activity with the majority (79) reacting only with lymphocytes from blood group A cats. Absorption of two such sera with A, AB and B erythrocytes and absorption of AB system reagents with lymphocytes from A and B blood group cats demonstrated that the A antigen is expressed on both erythrocytes and lymphocytes. Blood group and lymphocyte typing tests of foetuses indicated that the A antigen is present on these tissues as early as 46 days gestation. The erythrocytic B antigen could not be demonstrated on lymphocytes although a single antiserum, which reacted against lymphocytes from group B cats, was found. Several sera containing anti-lymphocytic antibodies which were not related to the AB type were also detected.     

The effect of UV irradiation and of UV-irradiated autologous blood on the functional state of human peripheral blood lymphocytes

The effect of UV irradiation (UVI, 254 nm) and of UV-irradiated autologous blood on the spontaneous and mitogen-induced DNA-synthetic activity of intact lymphocytes has been studied. Lymphocytes were isolated from nonirradiated and irradiated blood, and from the mixture of UV-irradiated blood with the intact one in the volume ratio close to that in the blood stream during UV-irradiated blood autotransfusion (1:10, 1:40, 1:160). It has been shown that UVI of the whole blood caused in some donors the increase in spontaneous DNA synthesis, while in others the decrease or no statistically significant changes were observed. The analysis of the results obtained shows an inverse relation of the UVI effect to the initial level of spontaneous DNA synthesis (r = -0.68). In contrast to direct UVI effect, an addition of UV-irradiated blood to the autologous intact one resulted in an increase in spontaneous DNA synthesis in lymphocytes of all the samples examined. A 7-day cocultivation of lymphocytes, isolated from irradiated and nonirradiated blood samples, revealed a 1.8 times increase compared to the calculated value. The mitogen-induced DNA synthesis has a low sensitivity to UV rays, since the mitogens and the irradiation of optical range have presumably the common targets. It is assumed that photomodification of HLA-D/DR antigens can be a trigger mechanism for activation of immunocompetent cells by UVI.     

Role of monocytes in the inhibitory effect of calcitriol on PHA-stimulated lymphocytes

The possible role played by monocytes in the inhibitory effect of calcitriol on phytohemagglutinin (PHA)-stimulated lymphocyte proliferation was assessed by testing the effect of this sterol under different cell culture conditions. Calcitriol had a dose-dependent inhibitory effect on lymphocyte proliferation in concentrations ranging from 10(-10) up to 10(-8) M. The effect of 10(-9) M calcitriol was almost completely abolished by: a) monocyte depletion, b) inhibition of prostaglandin (PG) synthesis by indomethacin, and c) addition of exogenous interleukin-2 (IL-2). These results suggested that the inhibitory effect of calcitriol was mediated through monocytes. This possibility was substantiated by the following observations: a) the calcitriol inhibitory effect was restored when autologous adherent cells were added to monocyte-depleted PBM cells; b) the supernatant of adherent cells cultured for 24 hours in the presence of calcitriol exerted a marked inhibitory effect on lymphocyte proliferation; and c) this effect was not longer evident when adherent cells were cultured in the presence of calcitriol plus indomethacin. These data support the hypothesis that calcitriol acts, at least partially, through the monocytes, inducing an increased release of PG, with subsequent inhibition of IL-2 synthesis, then resulting in a decreased lymphocyte proliferation.     

ABH blood group antigens in O-glycans of human glycophorin A

The major O-linked oligosaccharide structures attached to human glycophorin A (GPA) have been extensively characterized previously. Our own recent findings, obtained by immunochemical methods, suggested the presence of blood group A and B determinants in O-glycans of human glycophorin originating from blood group A or B erythrocytes, respectively. Here, we elucidate the structure of O-glycans, isolated from GPA of blood group A, B, and O individuals by reductive beta-elimination, carrying A, B or H blood group epitopes, respectively. Structural studies based on nanoflow electrospray-ionization tandem mass spectrometry and earlier reported data on the carbohydrate moiety of GPA and ABH antigens allowed us to conclude that these blood group epitopes are elongations of the beta-GlcNAc branch attached to C-6 of the reducing GalNAc. The galactose linked to C-3 of the reducing GalNAc carries NeuAcalpha2-3 linked residue. Identified here O-glycans were found in low amounts, their content estimated at about one percent of all GPA O-glycans. These O-glycans with type-2 core, carrying the blood group A, B or H determinants, have not been identified in GPA so far. Our results demonstrate the efficacy of nanoESI MS/MS in detecting minor oligosaccharide components present in a mixture with much more abundant structures.     

Monoclonal autoantibodies to different epithelial structures of the thymus gland obtained by the immunization with streptococcal group A antigens

By the indirect immunofluorescence method it was shown to which epithelial thymus structures monoclonal antibodies (mAT) reacting with the different epidermal structures are directed. These mAT related to the autoantibodies were obtained earlier, as a result of lymphoid cells polyclonal activation, by the immunization of BALB/c mice with streptococcal group A nonspecific protein antigens of the cell wall. It was shown that mAT A6/1, reacting with the basal layer of the skin epithelium are directed to the epithelium of the cortical and medullar thymus zones, which is regarded as the so called endocrinal epithelium. These mAT, by the study with immunoblotting method, react with the protein of mV SOkD, B5/1 mAT to the skin epithelium, on the thymus sections react with the single cells around the Hassel bodies.     

Expression of interleukin-2 receptor on blood lymphocytes stimulated with allogeneic lymphocytes or autologous tumor cells

Summary The kinetics of interleukin-2 receptor (IL-2R) expression and the [³H]dT incorporation of blood lymphocytes after the first and the second stimulation with allogeneic leukocytes (primary and secondary MLC) or with the autologous tumor cells (primary and secondary MLTC) were compared. The expression of IL-2R paralleled the induction of DNA synthesis. The proportion of IL-2R⁺ cells of the unprimed donors peaked earlier in the secondary MLC as compared to the primary MLC (on days 3 and 5 respectively). In MLC of alloimmunized healthy individuals and in the MLTC of cancer patients the highest proportions of IL-2R⁺ cells were detected between days 2 and 3 after both the first and second stimulations. Thus the first in vitro stimulation in the MLTC showed similar kinetics to those of the secondary MLC of unprimed individuals and to the primary MLC response of the allo-immunized individuals. The findings in the MLTC substantiate the hypothesis that cancer patients can be sensitized to their own tumors. The kinetics of the appearance of the IL-2R together with the characteristics of the IL-2-propagated cultures provide useful information for the strategy of expansion of auto-tumor reactive lymphocyte populations.