The isolation of mouse antigens carrying H2-histocompatibility specificity: some preliminary studies

THE EXPRESSION OF HISTOCOMPATIBILITY ANTIGENS ON CELLULAR AND SUBCELLULAR MEMBRANES

The mouse isoantigens determined at the major histocompatibility locus known as H-2 have been found to be closely associated with the cellular surface membranes, with the membranes of the endoplasmic reticulum, and probably with those of the lysosomes as well. Mitochondrial membranes, on the other hand, show little or no H-2 antigen activity. Membrane material prepared from certain tissues, including brain and muscle, have no detectable H-2 antigenic activity. Evidence is presented which indicates that all of the H-2 antigens of the genome are expressed as a unit, supporting the hypothesis that the complex H-2 genetic locus consists of a single cistron. It is postulated that these histocompatibility antigens form some structural or functional unit in the membranes of cells.

Chemical characteristics of microsomal liver specific antigens in the rat

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Mouse histocompatibility isoantigens derived from normal and from tumour cells

A simple method is described for preparing mouse histocompatibility antigens of high specific activity. Material is eluted from cells in hypotonic salt without allowing cytolysis; a suitable degree of hypotonicity depends on the cell type. Specificities determined by H-2 and some non-H-2 alleles have been measured by inhibition of release of radioactivity from labelled target cells incubated in isoantiserum and complement. Certain tumour cells and the antigens isolated from them have aberrant histocompatibility antigen composition.

Naturally occurring soluble H-2 specificity in mouse tissues

Liberation of radioactive chromium from labelled ascites tumour cells by mouse isoantiserum in the presence of complement has been used as a measure of cytotoxic H-2 antibody.

Specific inhibition of this reaction has been used to demonstrate the presence of substances carrying H-2 activity in saline extracts of normal and neoplastic tissues. The substances are not sedimented in 1 hour at 105,000 g, do not diffuse through dialysis tubing and are quantitatively precipitated between 25 and 50 per cent saturation with ammonium sulphate.

ULTRASTRUCTURAL AND HAEMODYNAMIC STUDIES IN CANINE RENAL TRANSPLANTS

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MOUSE TISSUE CELL ANTIGENS. SOME PROPERTIES OF CELL-BOUND COMPONENTS

Rabbit antisera against mouse cells have been absorbed with normal mouse serum and used to detect mouse cell-bound antigens. Mouse ascites tumour cells and their products have mainly been used as source of antigens but those described here are normal mouse components. Seven antigens have been found by agar diffusion precipitin methods and data are given to show that each is a separate molecular entity. Information is provided for the identification of each component.

A SEROLOGICAL ANALYSIS AND COMPARISON OF VARIOUS PREPARATIONS OF MOUSE H-2 HISTOCOMPATIBILITY ANTIGEN

Antigenic products from four laboratories have been tested under controlled conditions in simultaneous in vivo and in vitro tests. The greatest specific activity in vitro was given by an insoluble product derived from cell-free ascites fluid, but considerable activity was also obtained with another insoluble antigen produced by a different method from Sa-1 tumour cells. Two of the products gave non-specific inhibition in vitro and two were inactive. Six products were injected into C57BL mice; five were found to elicit antibody formation; one, inactive in vitro, was also inactive as measured in vivo by haemagglutinin production.