PROPERTIES OF MOUSE IMMUNE T‐INTERFERON (TYPE II)

I would like, if I may, to start my talk on T-interferon by attempting to justify the reason for this nomenclature. We used the term “Immune Interferon” for the first time in 1972’ to define the types of interferon (IF) exclusively produced in immunocompetent cells stimulated by specific antigens or by nonspecific stimulants like mitogens and lectins. The term “immune-interferon” is frequently used in the literature. The work done in this field by our group and other l abora t~ r i e s~ -~ has led to the conclusion that there are two different types of immune-interferons: firstly, those induced by stimulants dependent on B lymphocytes-acid-stable, antigenically related to viral IF-and secondly, IFs induced by T-lymphocyte stimulants: these are acid-unstable and antigenically distinct from viral IF (FIGURE 1). We shall refer to these interferons as Type B and Type T, taking into account inducer selectivity exclusively. Youngner introduced another very popular nomenclature for antigeninduced IF. which he defined as acid-unstable and antigenically distinct from viral I F he called it Type I1 i n t e r f e r ~ n . ~ Immune and Type I1 interferon are often synonymous in the literature. However, according to the criteria we have just defined (antigenic properties and stability at acid pH) these terms cannot be used synonymously. As a function of these two criteria we therefore consider that among immune interferons a distinction must be made between Type T. which is similar to Youngner’s Type 11. and Type B, which shares some of the characteristics of viral interferon. This is schematized in FIGURE 2. We do not claim here to suggest a final classification for immune-induced IFs, for I think it is still too early to achieve this. The present comments simply aim to avoid the confusion caused by the use of the term “immune-interferon” as a synonym for Type I1 interferon. The T-interferon prototype used in our research over the past few years was prepared by PHA stimulation of mouse splenocytes. since, as you know, PHA stimulates T lymphocytes. The method has been optimalized and at the present time we are able to prepare considerable quantities of this interferon. The crude preparation has a