Low-molecular-weight polysaccharide antigens isolated from Rhodopseudomonas gelatinosa.

Strain-specific low-molecular-weight polysaccharides of different chemical compositions were obtained from cells of nine different wild-type strains of the phototrophic bacterium Rhodopseudomonas gelatinosa. The polysaccharides are free of typical capsule components like hexuronic or aminohexuronic acids but contain (except that of strain 39/2) substantial amounts of phosphorus. A number of unusual o-methyl sugars (2-o-methyl-D-galactose, 2,3-di-o-methyl-D-galactose, 2-o-methyl-L-fucose) as well as 3,6-dideoxy-D-xylo-hexose (abequose) were identified in the R. gelatinosa polysaccharides. o-Methyl and dideoxy sugars however, are typical constituents of O-specific chains of the lipopolysaccharides of gram-negative bacteria (Rhodospirillaceae and Enterobacteriaceae, respectively). Considering both the R-type character of the R. gelatinosa lipopolysaccharides and the occurrence of these strain-specific ETEROPOLYSACCHARIDES, THE ASSUMPTION SEEMS TO BE JUSTIFIED THAT THE LOW-MOLECULAR-WEIGHT POLYSACCHARIDES ARE RELATED TO O-specific chains of lipopolysaccharides (haptens) rather than to capsular or slime antigens. In serological terms the polysaccharides of R. gelatinosa have to be classified as K-antigens. They are able to cover the O-specificity of the respective different strains and confer on them additional specificity which is demonstrable by bacterial agglutination.     

HLA antigens and affective disorders

A total of 168 patients with different types of affective disorders were examined with respect to their HLA antigens. The frequency of the A10 antigen was found to be increased in the patients particularly in those with the unipolar type of disease. The frequency of the A1 antigen was decreased among unipolar patients. A decreased frequency of the B7 antigen was found in the total material of patients, and in particular in those with a bipolar type of disease. Our results were in disagreement with findings by other investigators. So far there is no conclusive evidence for association between any HLA antigen and affective disorders.     

HLA antigens in cardiomyopathic Chilean chagasics.

The distribution of HLA antigens in a sample of 124 Chagas serologically positive Chilean individuals was studied. The sample was subdivided according to the presence or absence of chagasic cardiomyopathy, in order to search for genetic differences associated with this pathological condition. The frequency of antigen B40 in the presence of antigen Cw3 was found to be significantly lower in subjects with cardiomyopathy. We tentatively suggest that the presence of these antigens among noncardiomyopathics is associated with a decreased susceptibility to develop chagasic cardiomyopathy in the Chilean population.     

Shared HLA antigens and reproductive performance among Hutterites.

Shared histocompatibility antigens between spouses may affect reproductive outcome adversely as a result of prenatal selection against compatible fetuses. Evidence from both animal and human studies suggest that histocompatible fetuses may not initiate a maternal immunologic response that prevents rejection of the embryo. Therefore, parents sharing HLA antigens may produce compatible fetuses and consequently experience a greater frequency of early fetal losses and show poorer reproductive outcome than couples not sharing antigens. In the Hutterites, an inbred human isolate that proscribes contraception, we tested the hypothesis that couples sharing HLA antigens have poorer reproductive outcomes than couples who do not. The Hutterites are characterized by high fertility and large family sizes. Couples that share zero (no. = 21), one (no. = 15), and more than one (no. = 10) HLA-A or HLA-B antigens were compared for reproductive performance. Median intervals between births were larger among couples that share more than one antigen in eight of 11 intervals examined. In addition, the median intervals from marriage to first, fifth, and tenth birth were consistently larger among couples that share more than one antigen. Differences among the groups appear to become larger with increasing parity, suggesting that the effect of histocompatibility on reproductive performance becomes more evident in later pregnancies. These differences in reproductive performance between couples that share zero, one, or more than one HLA-A or HLA-B antigens may have significant evolutionary consequences. However, our results demonstrate that sharing HLA antigens does not preclude normal pregnancy and caution should be exercised before concluding that shared HLA antigens are solely responsible for repeated fetal losses.     

The preparation of liposomes bearing human (HLA) transplantation antigens.

The incorporation of HLA antigens into liposomes is described. At and above the lipidphase-transition temperature, between 50 and 80% of the added antigenic activity may be incorporated into liposomes in the form of multilamellar vesicles. The antigen appears to be asymmetrically orientated with respect to the lipid bilayer.     

The HLA system antigens in delayed sexual development

Frequency distribution of HLA antigens of A and B loci was examined in 138 adolescent boys aged 14-18 with delayed sexual development (DSD) of stages I-III, residing in the north-eastern region of Ukraine. Increase of A28- and B40-antigens and haplotypes A1-B40, A28-B40, A10-B40 determination frequencies was established. There were revealed positive and negative correlation between some of HLA antigens and DSD. Relative and attributive risks of DSD formation were calculated.     

HLA antigens and clinical subgroups of schizophrenia

Frequencies of HLA A, B, C, and DR antigens were studied in 100 schizophrenic patients and 919 controls from South Sweden. The patients were diagnosed according to the DSM III criteria and divided into four clinical subgroups (hebephrenic, paranoid, residual, and undifferentiated). In the schizophrenic patients as a whole significant increases were found for A2, A3, B17, B27, and Cw2 and decreases for A1, A11, and B8. A previous positive association with A9 from the same population was not confirmed. A significant heterogeneity between the four clinical subgroups was found for A3 and Bw35. Most of the associations between HLA antigens and schizophrenia reported in the literature appear to be fortuitous and dependent on the large number of trials made. However, confirmed increases have been found for A9 and B17, and confirmed decreases have been observed for A1 and B7. Some evidence for a heterogeneity between clinical subgroups was found in the present as well as in previous investigations.     

HLA DR antigens and susceptibility to insulin-dependent diabetes mellitus.

Two novel analytic methods to evaluate the roles of the HLA alleles of the human major histocompatibility complex in disease predisposition have been formulated and applied to insulin-dependent diabetes mellitus (IDDM). The HLA-DR antigens, as they are presently defined, are shown not to directly predispose individuals to IDDM. This result does not discount the possibility that subdivision of the DR antigens will yield the predisposing agents. In Caucasian populations, after consideration of the predisposing effect of the antigens DR3 and DR4, the protective effect of DR2 in predisposition is demonstrated. Additionally, DR1 and possibly DRw8 exhibit a higher than expected frequency in patients.     

The immunologic and hematopoietic profiles of mesenchymal stem cells derived from different sections of human umbilical cord

Mesenchymal stem cells （MSCs） have been widely used in allogeneic stem cell transplantation. We compared im- munologic and hematopoietic characteristics of MSCs derived from whole human umbilical cord （UC）, as well as from different sections of UCs, including the amniotic membrane （AM）, Wharton＇s jelly （WJ）, and umbilical vessel （UV）. Cell phenotypes were examined by flow cytometry. Lymphocyte transformation test and mixed lymphocyte reaction were performed to evaluate the immuno-modulatory activity of MSCs derived from UCs. The mRNA expression of cytokines was detected by real- time polymerase chain reaction. Hematopoietic function was studied by co-culturing MSCs with CD34＋ cells iso- lated from cord blood. Our results showed that MSCs separated from these four different sections including UC, W J, UV, and AM had similar biological characteristics. All of the MSCs had multi-lineage differentiation ability and were able to differentiate into osteoblasts, adipocytes, and chondrocytes. The MSCs also inhibited the proliferation of allogeneic T cells in a dose-dependent manner. The relative mRNA expression of cytokines was examined, and the results showed that UCMSCs had higher interleukin-6 （IL6）, ILll, stem cell factor, and FLT3 expression than MSCs derived from specific sections of UCs. CD34＋ cells had high propagation efficiencies when co-cultured with MSCs derived from different sections of UCs, among which UCMSCs are the most efficient feeding layer. Our study demonstrated that MSCs could be isolated from whole UC or specific sections of UC with similar immuno- modulation and hematopoiesis supporting characteristics.     

HLA antigens, phytohemagglutinin stimulation, and corticosteroid response.

Although it is clear that the major histocompatibility complex is associated with lymphocyte glucocorticoid sensitivity in mice, there has been less evidence for a similar relationship in man. We have typed 158 individuals for: (1) 13 A locus and 16 B locus antigens, (2) degree of stimulation of their purified lymphocytes by phytohemagglutinin A (PHA), and (3) degree of inhibition of the PHA stimulation by prednisolone and prednisolone-21-hemisuccinate. In contrasts of individuals with a particular antigen (homozygous or heterozygous) with all remaining individuals, HLA-B7 was found to be associated with an enhancing effect on the log stimulation by PHA while other antigens of these series did not have significant associations. In similar contrasts, A10 was associated with a decrease in sensitivity to glucocorticoid inhibition of PHA stimulation as measured by the log I50 of the suppression of PHA stimulation. Other antigens of these series were not found to have significant associations with the glucocorticoid sensitivity of lymphocytes in this assay.