Macrophage spreading inhibition test as an alternate method for in vitro assessment of cell-mediated immunity against Entamoeba histolytica.

During cellular immune responses sensitized lymphocytes release a number of mediators collectively known as 'lymphokines'. The assaying of macrophage spreading inhibition (MSI) factor released by sensitized lymphocytes was employed as an alternative procedure for in vitro detection of cell-mediated immunity (CMI) in animals immunized with amoeba antigen preparation. The MSI test was compared with macrophage migration inhibition test. A well defined CMI was detectable in animals immunized by amoebic antigen in combination with Freund's complete adjuvant (FCA). Macrophage spreading was found greatly inhibited when peritoneal exudate cells from these animals were cultured in the presence of specific antigen. The optimal time for the development of typical reaction was 30 min. Incubation for a longer time resulted in macrophage clumping.