The testis and epididymis are productively infected by SIV and SHIV in juvenile macaques during the post-acute stage of infection.
BACKGROUND
Little is known about the progression and pathogenesis of HIV-1 infection within the male genital tract (MGT), particularly during the early stages of infection.


RESULTS
To study HIV pathogenesis in the testis and epididymis, 12 juvenile monkeys (Macacca nemestrina, 4-4.5 years old) were infected with Simian Immunodeficiency Virus mac 251 (SIVmac251) (n = 6) or Simian/Human Immunodeficiency Virus (SHIVmn229) (n = 6). Testes and epididymides were collected and examined by light microscopy and electron microscopy, at weeks 11-13 (SHIV) and 23 (SIV) following infection. Differences were found in the maturation status of the MGT of the monkeys, ranging from prepubertal (lacking post-meiotic germ cells) to post-pubertal (having mature sperm in the epididymal duct). Variable levels of viral RNA were identified in the lymph node, epididymis and testis following infection with both SHIVmn229 and SIVmac251. Viral protein was detected via immunofluorescence histochemistry using specific antibodies to SIV (anti-gp41) and HIV-1 (capsid/p24) protein. SIV and SHIV infected macrophages, potentially dendritic cells and T cells in the testicular interstitial tissue were identified by co-localisation studies using antibodies to CD68, DC-SIGN, alphabetaTCR. Infection of spermatogonia, but not more mature spermatogenic cells, was also observed. Leukocytic infiltrates were observed within the epididymal stroma of the infected animals.


CONCLUSIONS
These data show that the testis and epididymis of juvenile macaques are a target for SIV and SHIV during the post-acute stage of infection and represent a potential model for studying HIV-1 pathogenesis and its effect on spermatogenesis and the MGT in general.
Shehu-Xhilaga
Miranda
M
Infectious Diseases Unit, Alfred Hospital, Prahran, Australia. Miranda.Xhilaga@med.monash.edu.au
Kent
Stephen
S
Batten
Jane
J
Ellis
Sarah
S
Van der Meulen
Joel
J
O'Bryan
Moira
M
Cameron
Paul U
PU
Lewin
Sharon R
SR
Hedger
Mark P
MP
D000818:Animals; D003713:Dendritic Cells / Q000821:virology; D004195:Disease Models, Animal; D004822:Epididymis / Q000473:pathology / Q000821:virology*; D016655:HIV Core Protein p24 / Q000032:analysis; D015700:HIV Envelope Protein gp41 / Q000032:analysis; D015497:HIV-1 / Q000302:isolation & purification*; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000821:virology; D008254:Macaca nemestrina; D008264:Macrophages / Q000821:virology; D008297:Male; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D012367:RNA, Viral / Q000032:analysis; D016097:Simian Acquired Immunodeficiency Syndrome / Q000821:virology*; D015302:Simian Immunodeficiency Virus / Q000302:isolation & purification*; D013093:Spermatogonia / Q000821:virology; D013601:T-Lymphocytes / Q000821:virology; D013737:Testis / Q000473:pathology / Q000821:virology*
D016655:HIV Core Protein p24; D015700:HIV Envelope Protein gp41; D012367:RNA, Viral