PHENOTYPICAL HETEROGENEITY OF TESTICULAR MACROPHAGES DENDRITIC CELLS IN NORMAL ADULT MICE - AN IMMUNOHISTOCHEMICAL STUDY

The distribution of macrophage/dendritic cell antigens was investigate d immunohistochemically in frozen testis sections of normal A/J mice u sing a panel of rat monoclonal antibodies against murine macrophage/de ndritic cell antigens (F4/80, BM8, MP23, MOMA1, MOMA2, M5/114, BMDM1 a nd NLDC145). Sections of lymphoid organs were employed as positive con trols. Stained macrophages/dendritic cells in the testicular interstit ium were various in shape, such as irregular-, elongate-, round- or ov al-shaped cytoplasm with short or long cytoplasmic protrusions, but, t he most conspicuous morphology was irregular. The testicular macrophag es/dendritic cells were subdivided into four types of cells by their l ocalization; various-shaped cells associated with Leydig cells and oth er interstitial cells (Type I); stretched cells attached to the semini ferous tubular wall (Type II); stretched cells attached to the blood v essel wall (Type III); and stretched cells attached to the inner side of the testicular capsule (Type IV). Examination of the staining patte rn of the various antibodies showed that the macrophage/dendritic cell antigens differed from each other in amount present and localization, indicating phenotypical heterogeneity of the testicular macrophages. Additionally, a few macrophages were identified in the testicular caps ule and in the tubuli recti but never in the seminiferous tubules.