The antigenic stimulus in transplantation immunity

Role of uteroglobin and transglutaminase in masking the antigenicity of implanting rabbit embryos

Using rabbit as a model, the roles of uteroglobin (UG) and transglutaminase (TG) in masking the antigenicity of early developing mammalian embryo have been investigated. Maternal lymphocytes in vitro, when mixed with mitomycin-C inactivated blastomeres, incorporated H3-thymidine, suggesting recognition of embryonic antigens by these cells. However, pretreatment of blastomeres with pregnant uterine fluid (PUF) or with UG alone or in combination with TG (coagulation factor XIIIa), resulted in a significant and dose-dependent suppression of H3-thymidine incorporation into these lymphocytes. A complete suppression was achieved at a concentration of 250 micrograms of UG/ml, in the absence of TG. However, in the presence of TG, only 1.0 micrograms of UG/ml was required for total suppression. Neither nonpregnant uterine fluid (NPUF), nor myoglobin, a nonspecific protein similar in molecular weight to UG, had any suppressive effect. Incubation of uteroglobin with anti-UG or TG with its antiserum prior to the pretreatment of blastomeres eliminated the suppressive effect of these proteins. Inhibition of TG by neopentyl chloroethyl nitrosourea (NPCNU) also eliminated the suppressive effects of uteroglobin on H3-thymidine incorporation into maternal lymphocytes. These results suggest that in the pregnant uterus UG in conjunction with TG may play a specific role in masking the antigenicity of developing embryos during implantation.

Enzymatic chemical modification of human amniotic membrane and skin as a means for the preparation of biological dressing

A non-antigenic biological dressing of amniotic membrane and skin was prepared by treatment with the enzyme ficin and dialdehyde starch. The dressing was tested in experimental animals for the coverage of full-thickness skin defects. The healing process was studied, as well as the durability of the biological dressing. Testing for flexibility, adherence and antigenicity, there was no change in the ficin-treated dressing when used even after being stored for a period of up to 2 years. The enzyme treatment did not result in a superior biological dressing.

Mechanisms of gonadal differentiation

Sex differentiation is the result of the translation of genetic sex into gonadal sex. Without recognizable masculinizing signals the embryonic gonad will undergo ovarian differentiation. The main determinant of gonadal differentiation appears to be the presence or absence of a cell surface antigen, called H-Y antigen. The regulation of H-Y antigen expression is complex and involves the interaction between regulatory sites on the Y chromosome, the X chromosome, and possibly the autosomes.

Chemical markers of transplantation individuality solubilized with sonic energy

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Serological and immunogenic activity of soluble mouse transplantation antigens controlled by the H-2 locus

The solubilization and partial purification of mouse transplantation antigens were monitored by (1) an in vitro assay for alloantigenic specificities and (2) an in vivo assay for transplantation antigens controlled by the H-2 histocompatibility locus. Antigens from A/J mice were solubilized by papain and fractionated on a Sephadex G-150 column. The eluate showed a 280 nm absorbance peak (F(1)) in the excluded volume and two peaks (F(2) and F(3)) in the included volume. H-2 specificities 1, 3, 4, 5, 11, 23, and 28 were confined to a single peak in the F(2) fraction. Fractions F(1), F(2), and F(3), were tested for their ability to accelerate skin graft rejection in noncoisogenic strains which differ at both H-2 and non-H-2 loci, and coisogenic strains which differ only at the H-2 locus. All fractions produced significant acceleration of graft rejection in the noncoisogenic strains, but only fraction F(2) produced significant acceleration in the coisogenic strains. These findings indicate that H-2 transplantation antigens detected by our in vivo assay, and H-2 alloantigenic specificities detected by our in vitro assay are solubilized by papain and are eluted in the same peak during Sephadex fractionation.

Electrophoretic purification of a water-soluble guinea pig transplantation antigen

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