Isolation of the Heterogenetic "Mononucleosis Antigen" from the Stroma of Beef Erythrocytes

Preparation of an Infectious Mononucleosis Receptor from Sheep Erythrocyte Stroma

“…Thus, the agglutinins of the serum sickness sera must react with a limited number of determinant sites on the red cell. The failure of the alcohol extracts to inhibit IM sera is contradictory to some recently published results [10], although in agreement with the original investiga tions of sheep erythrocyte receptor solubility by Schwarzweiss and T omcsik [23]. The only major difference between the extraction proce dure used here and that of F letcher and Woolfolk [10] who obtained lM-active 75% ethanol fractions, seems to be the nature of the starting material.…”

“…Most of the prior investigations into the nature of 1M and serum sickness receptors of sheep red cells have found the major differences between the two to be in alcohol solubility, i.e. the sheep IMR is not alcohol-soluble but the serum sickness receptor is, although with cattle red blood cells the situation is somewhat different, the IMR being readily extracted into 80% ethanol, while the serum sickness receptor is soluble in 100% ethanol [18,23,24], Whatever the reason, it can be stat ed that under the conditions used here, the 75% ethanol extracts certainly do not carry the 1M antigen and may be serum-sickness-specific.…”

“…Subsequently, it was shown that such sera also react ed strongly with other animal erythrocytes [1,9], The discovery of an an tigen on various animal red cells which specifically reacts with antibodies produced in IM generated numerous attempts to isolate it and to charac terize the haptenic groupings responsible for its interaction with the IMspecific antibodies. The early studies which concentrated on solubilizing the IM 'receptor' (IMR) of sheep and cattle erythrocytes by hot organic solvents produced only crude fractions [1,9,18,23,35]; however, subse quent investigations succeeded in extracting a moderately active IMR preparation from cattle erythrocyte stroma with phenol [28] and thereaft er a highly active IMR was prepared by a combination of alkaline homo genization, organic extraction and fractional precipitation [2,3,26]. This isolation procedure was completely ineffective with the sheep IMR, but a modified phenol-saline extraction was found which provided a suitable method of isolation for the ovine receptor [5].…”

Action of Proteolytic Enzymes on the “Mononucleosis Antigen” in Sheep and Beef Erythrocytes

“…Since the M antigen in beef stroma and an old preparation of iso lated M antigen resist prolonged treatment with papain as well as trypsin, it may be assumed that the M antigen in beef erythro cytes differs in some way from that of sheep. This may seem a surprising and unexpected result but it may be mentioned in this connection that Schwarzweiss and Tomcsik (8) found that the method devised by them for the isolation of the M antigen from beef stroma when applied to sheep stroma led to its partial de struction. This fact lends support to the theory that the resistance of the M substance is less in sheep than in beef erythrocytes not only towards papain but also towards ethanol at higher tempera tures.…”

“…Nevertheless from the results obtained by paper chromatography, they assumed that the M substance is a rather complex polypep tide-lipid substance with the immunologic activity residing in the polypeptide portion of the molecule. This assumption was also based to some extent on the proteolytic action of pepsin and tryp sin on the purified M substance using the technique of absorption applied by Tomcsik and Schwarzweiss (8,12,13) for this purpose. Tomcsik and Schwarzweiss observed that neither trypsin nor pepsin had any appreciable effect on the M antigen in sheep and beef stroma as measured by its ability to absorb the M anti body (13).…”