Experimental inoculation of the adult rat testis with Sendai virus: effect on testicular morphology and leukocyte population.
BACKGROUND
Surprisingly little is known about the interactions between viruses and the male uro-genital tract. These are important, as viral testicular orchitis, induced by mumps or human immunodeficiency virus (HIV) infection for example, can lead to sterility. Moreover, semen is an essential vector in the propagation of sexually transmissible viral diseases. Here, we studied the effects of testicular infection with Sendai virus, a virus related to mumps virus, on the cellular distribution of viral particles and on testicular morphology, with particular attention to the testicular leukocyte population.


METHODS
At 5, 9, 11 or 24 h post-injection of Sendai virus through the scrotum, the testes were fixed for morphological and immunohistological studies. Localization of virus particles and numeration of leukocytes were performed using specific antibodies and morphological criteria.


RESULTS
As early as 5 h post-injection, a rapid and massive infiltration of leukocytes was observed in the interstitial tissue. The peritubular cell layer and the most external part of the basal portion of the seminiferous tubules were altered. The virus was diffusely located within the interstitial tissue 9 h following the injection whereas, after 24 h, viral proteins were restricted to the cytoplasm of infiltrated leukocytes. The number of leukocytes increased with time post-injection. Thus, 24 h post-injection, CD3+ T-cell number was 3-fold higher, ED1+ monocyte number was 4-fold higher and polynuclear cell number was 600-fold higher than in the control testes (P<0.001 all observations). In contrast, the population of resident macrophages was unaffected by Sendai virus.


CONCLUSIONS
Testicular viral infection causes inflammation including rapid recruitment of leukocytes. The experiments presented here provide a model for further studies on the etiopathology of viral orchitis, in particular that caused by mumps virus.
Melaine
N
N
GERM-INSERM U435, Université de Rennes I, Campus de Beaulieu, 35042 Rennes, France.
Ruffault
A
A
Dejucq-Rainsford
N
N
Jégou
B
B
D000818:Animals; D004195:Disease Models, Animal; D006801:Humans; D007962:Leukocytes / Q000145:classification / Q000473:pathology*; D008297:Male; D009107:Mumps / Q000473:pathology / Q000821:virology; D009920:Orchitis / Q000473:pathology* / Q000821:virology; D051381:Rats; D017207:Rats, Sprague-Dawley; D010253:Respirovirus Infections / Q000473:pathology* / Q000821:virology; D029082:Sendai virus / Q000302:isolation & purification / Q000472:pathogenicity*; D013737:Testis / Q000473:pathology* / Q000821:virology*