Cytomegalovirus infection of murine testicular interstitial Leydig cells

Abstract

We studied the susceptibility of mouse testicular interstitial Leydig cells to cytomegalovirus both in vivo and in vitro. The in vivo studies included intratesticular and intraperitoneal infection of 6-week-old mice with murine cytomegalovirus (MCMV); the in vitro studies involved an MCMV-Leydig cell interaction using a Leydig tumor cell line (1-10). MCMV-specific antigens were detected in interstitial Leydig cells in sections of MCMV-inoculated testes by an indirect immunofluorescence test. MCMV DNA was also localized in the same testes cells derived from mice, which received intratesticular and intraperitoneal MCMV inoculations, respectively, by in situ DNA-RNA hybridization. Cytopathic effects were seen in MCMV-infected 1-10 cell cultures 2 or more days after exposure to MCMV. The infected cells showed intranuclear inclusions characteristic of cytomegalovirus when stained with May-Grunwald-Giemsa stain. The indirect immunofluorescence test was also positive with MCMV-infected 1-10 cells. MCMV DNA was detected in these cells by in situ DNA-RNA cytohybridization, and the presence of viral particles in MCMV-infected 1-10 cells was confirmed by electron microscopy. Thus, we conclude that the interstitial Leydig cell is susceptible to MCMV infection both in vivo and in vitro.Cytomegalovirus (CMV) infection is one of the most common congenital infections in humans and can lead to a wide variety of birth defects (4,11,13,19,23). The genital system is often among the affected areas. Human CMV is frequently isolated from human semen (14; unpublished data). The origin of infection and susceptible cell types in the testes are still unclear. Therefore, as an initial step, we used the murine CMV (MCMV) system to study this problem with the interstitial Leydig cell. Testicular interstitial Leydig cells develop very early in life and may be one of the target cells for CMV-induced congenital defects of the male genital system. Steroidal secretions of Leydig cells are required for the development and maintenance of the male reproductive function (5). It is possible that infection of Leydig cells may contribute to venereal transmission of CMV and also disrupt the Leydig cell function. To investigate the susceptibility of Leydig cells to CMV infection, we inoculated mice intratesticularly and intraperitoneally with MCMV and studied the outcome. We also studied the CMV-Leydig cell interactions in vitro using a Leydig cell line (1-10; American Type Culture Collection, Rockville, Md.) derived from a mouse testicular interstitial cell tumor (22). Both our in vivo and in vitro studies demonstrate that these cells are susceptible to MCMV. MATERIALS AND METHODSVirus. Stock salivary gland MCMV (Smith strain) was plaque purified and passaged (multiplicity of infection [MOI], 0.005), in either secondary or tertiary mouse embryo fibroblast (MEF) cultures before use. MEF cultures were derived from Sendai virus-free late-pregnancy CF-1 mouse embryos and were cultured in minimum essential medium containing 100 U of penicillin and 100 ,ug of s...

Pathogenesis of murine cytomegalovirus infection: identification of infected cells in the spleen during acute and latent infections

“…As with HCMV, MCMV infects a variety of organs and cell types. The spleen, liver, adrenal gland, salivary gland, kidney, lung, ovary, and testis have been shown to be infected (1,2,8,9,23,39,42,44), and in most cases, the infected cells appeared to be epithelial, interstitial, or parenchymal cells. Neurons are also infected by MCMV (13), and occasional infected endothelial cells have been observed (39,44).…”

Murine cytomegalovirus infection of mouse testes

“…As an initial step in the determination of the origin of testicular infection and the susceptible cell types in the testes, we examined the interaction of MCMV with the testicular interstitial Leydig cells of mice. Our results indicated that Leydig cells are susceptible to MCMV both in vivo and in vitro (3). In this paper, we are reporting evidence that MCMV can replicate in sperm cells of immunologically competent mice.…”

“…1). It also caused infection of the Leydig cells located in the testicular interstitial spaces, as shown in our previous report (3). The testes were examined by subjecting frozen testicular sections to in situ [3H]cRNA-DNA cytohybridizations (6, 13).…”

“…The genital organs of mice are also susceptible to murine cytomegalovirus (MCMV) infection (3,6,8,20). Since MCMV can be found in the ejaculate of infected males, the virus may be sexually transmitted, thereby affecting the outcome of pregnancy (20; our unpublished data).…”

Some genomic and biological characteristics of selected bovine herpesviruses

“…Likewise, Dutko and Oldstone (1979), using the same type of techniques, localized MCMV DNA in purified spermatozoa and in immature sperm cells, giving strong support to the argument of an acute and latent infection by MCMV of male germ-line cells. In addition, it was reported that interstitial Leydig cells of testicles are susceptible to MCMV infection both vivo and' in vitro (Baskar et al, 1983). These authors suggested the possibility that MCMV, by infecting Leydig cells, may upset hormonal balance and impede gametogenesis.…”