Studies of the Producer Cell of Interferon in Human Lymphocyte Cultures

The producer cells of interferon were studied in human leucocyte cultures stimulated by a variety of stimulants, including phytohemagglutinin (PHA), pokeweed mitogen (PWM), Corynebacterium parvum (CP) and Herpes Simplex Virus (HSV). When the cells were fractionated by the use of neuraminidase-treated sheep red blood cells (SRBC), the T cell population responded with interferon production to PHA and PWM but not to CP or HSV. However, the non-T population showed a vigorous response to the latter two stimuli. In contrast, nylon column eluate cells enriched for T cells responded well to CP and HSV with production of interferon. To resolve these contradictory data, we have used combinations of techniques. Nylon column eluate cells were further separated by SRBC and it was found that the nylon non-adherent rosetting cell did not produce interferon in response to HSV or CP whereas the nylon-nonadherent non-rosetting cell did. In additional experiments more elaborate techniques were used. Leucocytes were treated by plastic adherence and iron filings, passed over a nylon column and subsequently over an Ig-anti-Ig column, then rosetted with SRBC. Again only the non-rosetting population produced interferon. In parallel experiments the capacity of the different cell populations to lyse three types of target cells in a chromium release assay as a test for natural killer (NK) cell activity was investigated. There was some correlation between interferon production and NK cell activity. Thus, our data indicate that interferon is produced by non-T, non-B cells, possibly by cells related to NK cells.