Immunohistochemical localization of retroviral-related antigens expressed in normal baboon placental villous tissue.
Endogenous retroviral particles (ERVs) have been detected in the genome of all eukaryotes. They are generally non-pathogenic except in mice where they have been found to induce tumors and immunological disorders. The ERVs have morphological features consistent with type-C retroviral particles and are commonly expressed in normal placental villous tissues. ERVs may have a role in the regulation of placental gene expression, syncytiotrophoblast formation, or pregnancy-related immunosuppression. In this study, well-characterized antibodies (monoclonal and polyclonal antibodies) raised against retroviral proteins (anti-HIV and anti-SIV) and endogenous retroviral (ERV) particles were assessed for their cross-reactivity (by using immunohistochemistry) with normal baboon placental and other adult tissues. The monoclonal antibodies to exogenous retroviral proteins (anti-HIV-2 gp120, anti-HIV-1 gp41, anti-SIVmac p27, anti-HIV-1 RT, and anti-HIV-2 core protein) showed specific immunohistochemical reactivity with the syncytiotrophoblast. Antibodies to endogenous retroviral gene products (anti-ERV3 env, anti-HERV-K RT, and anti-HERV-K env) also reacted in a similar manner and did not cross-react with other adult tissues. These studies have shown that retroviral-cross-reactive proteins are expressed in baboon placental syncytiotrophoblast and may have a role to play at the feto-maternal interface.
Langat
D K
DK
Institute of Primate Research, Karen, Nairobi, Kenya.
Johnson
P M
PM
Rote
N S
NS
Wango
E O
EO
Owiti
G O
GO
Mwenda
J M
JM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000956:Antigens, Viral / Q000032:analysis*; D002824:Chorionic Villi / Q000276:immunology*; D003429:Cross Reactions; D020077:Endogenous Retroviruses / Q000235:genetics / Q000276:immunology*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D015686:Gene Products, env / Q000276:immunology; D015483:HIV Antibodies / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000276:immunology; D015700:HIV Envelope Protein gp41 / Q000276:immunology; D054303:HIV Reverse Transcriptase / Q000276:immunology; D015498:HIV-2 / Q000276:immunology; D051379:Mice; D010215:Papio / Q000276:immunology*; D011247:Pregnancy; D015302:Simian Immunodeficiency Virus / Q000276:immunology; D014758:Viral Core Proteins / Q000276:immunology
D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D015686:Gene Products, env; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D015700:HIV Envelope Protein gp41; D014758:Viral Core Proteins; D054303:HIV Reverse Transcriptase