title: High cell-free virus load and robust autologous humoral immune responses in breast milk of simian immunodeficiency virus-infected african green monkeys.
abstract: The design of immunologic interventions to prevent postnatal transmission of human immunodeficiency virus (HIV) will require identification of protective immune responses in this setting. Simian immunodeficiency virus (SIV)-infected rhesus monkeys (RMs), a species that develops an AIDS-like illness following experimental infection, transmit the virus at a high rate during breastfeeding. In contrast, postnatal transmission of SIV occurs rarely or not at all in natural, asymptomatic primate hosts of SIV. These contrasting transmission patterns provide a unique opportunity to study mechanisms that evolved to protect suckling infants from SIV infection. We compared the virologic and immunologic properties of milk of SIV-infected and uninfected natural hosts of SIV, African green monkeys (AGMs), to that of RMs. Interestingly, despite a low number of milk CD4(+) T lymphocytes in uninfected AGMs, milk virus RNA load in SIV-infected AGMs was comparable to that of SIV-infected RMs and that in AGM plasma. This observation is in contrast to the relatively low virus load in milk compared to that in plasma of SIV-infected RMs and HIV-infected women. Milk of SIV-infected AGMs also displayed robust virus-specific cellular immune responses. Importantly, an autologous challenge virus-specific neutralization response was detected in milk of five of six SIV-infected AGMs that was comparable in magnitude to that in plasma. In contrast, autologous challenge virus neutralization was not detectable in milk of SIV-infected RMs. The autologous virus-specific adaptive immune responses in breast milk of AGMs may contribute to impedance of virus transmission in the infant oral/gastrointestinal tract and the rarity of postnatal virus transmission in natural hosts of SIV.
authors: Duke Human Vaccine Institute, Duke University Medical Center, Box 103020, Durham, NC 27710, USA.
authors: Andrew B
authors: AB
authors: Wilks
authors: James R
authors: JR
authors: Perry
authors: Elizabeth P
authors: EP
authors: Ehlinger
authors: Roland C
authors: RC
authors: Zahn
authors: Robert
authors: R
authors: White
authors: Marie-Claire
authors: MC
authors: Gauduin
authors: Angela
authors: A
authors: Carville
authors: Michael S
authors: MS
authors: Seaman
authors: Joern E
authors: JE
authors: Schmitz
authors: Sallie R
authors: SR
authors: Permar
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology; D002522:Chlorocebus aethiops; D005260:Female; D015483:HIV Antibodies / Q000276:immunology; D016131:Lymphocyte Subsets / Q000276:immunology; D008253:Macaca mulatta; D008895:Milk, Human / Q000276:immunology* / Q000821:virology*; D009500:Neutralization Tests; D010949:Plasma / Q000821:virology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000821:virology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology* / Q000302:isolation & purification*; D019562:Viral Load
chemical_list: D057134:Antibodies, Neutralizing; D015483:HIV Antibodies