Testicular immune cell populations and macrophage polarisation in adult male mice and the influence of altered activin A levels

S. Indumathy, D. Pueschl, B. Klein, D. Fietz, M. Bergmann, H. C. Schuppe, N. Da Silva, B. E. Loveland, M. J. Hickey, M. P. Hedger, K. L. Loveland

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13 Citations (Scopus)


Detailed morphological characterization of testicular leukocytes in the adult CX3CR1gfp/+ transgenic mouse identified two distinct CX3CR1+ mononuclear phagocyte (macrophage and dendritic cell) populations: stellate/dendriform cells opposed to the seminiferous tubules (peritubular), and polygonal cells associated with Leydig cells (interstitial). Using confocal microscopy combined with stereological enumeration of CX3CR1gfp/+ cells established that there were twice as many interstitial cells (68%) as peritubular cells (32%). Flow cytometric analyses of interstitial cells from mechanically-dissociated testes identified multiple mononuclear phagocyte subsets based on surface marker expression (CX3CR1, F4/80, CD11c). These cells comprised 80% of total intratesticular leukocytes, as identified by CD45 expression. The remaining leukocytes were CD3+ (T lymphocytes) and NK1.1+ (natural killer cells). Functional phenotype assessment using CD206 (an anti-inflammatory/M2 marker) and MHC class II (an activation marker) identified a potentially tolerogenic CD206+MHCII+ sub-population (12% of total CD45+ cells). Rare testicular subsets of CX3CR1+CD11c+F4/80+ (4.3%) mononuclear phagocytes and CD3+NK1.1+ (3.1%) lymphocytes were also identified for the first time. In order to examine the potential for the immunoregulatory cytokine, activin A to modulate testicular immune cell populations, testes from adult mice with reduced activin A (Inhba+/−) or elevated activin A (Inha+/−) were assessed using flow cytometry. Although the proportion of F4/80+CD11b+ leukocytes (macrophages) was not affected, the frequency of CD206+MHCII+cells was significantly lower and CD206+MHCII correspondingly higher in Inha+/− testes. This shift in expression of MHCII in CD206+ macrophages indicates that changes in circulating and/or local activin A influence resident macrophage activation and phenotype and, therefore, the immunological environment of the testis.

Original languageEnglish
Article number103204
Number of pages8
JournalJournal of Reproductive Immunology
Publication statusPublished - Nov 2020


  • Flow cytometry
  • Lymphocytes
  • Mononuclear phagocytes
  • Morphometry
  • Testis

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