Cellular mediated immunity to the lymphogranuloma venereum agent

Abstract

A possible correlation between the skin test and the presence of a cellular mediated immunity has been investigated using a lymphogranuloma venereum (LGV) antigen. The macrophage inhibition (MI) and macrophage spreading inhibition (MSI) tests were used to detect evidence of a cellular mediated immunity. A positive correlation was obtained between the diameter of the skin reactions and the in vitro inhibition of macrophages. Further experimentation demonstrated that the in vitro inhibition of macrophages was not mediated by cytophilic antibodies but mediated partially or completely by a macrophage inhibition factor. Electrofocusing experiments were carried out on a sonicated LGV agent to isolate and identify the antigens which induced the cellular mediated immunity; four fractions with approximate pI (isoelectric point) values of 1.44, 1.38, 10.38, and 12.77 demonstrated a strong inhibition of macrophages in vitro. The antigen containing fractions had smaller amounts of nitrogen, higher ratios of non-reducing sugars per nitrogen content, and extremely high as well as low isoelectric point values as compared with fractions which exhibited no MSI reactions. The possibility of these antigens occurring as repeating units in the structure of the agent is discussed briefly.