Virus Killing by White Blood Cells in Breast Milk: How Breastfeeding Is Protective Against HIV
- Duration: 60 Mins
- Credits: 1 CERP, 1 L-CERP, 0.1 Midwifery CEU
- Handout: Yes
Abstract:
Unless access to clean water and appropriate infant formula is reliable, the World Health Organization does not recommend HIV-infected mothers stop breastfeeding. Remarkably, only about 15% of babies exclusively breastfed by their HIV-infected mothers become infected with HIV. This suggests that although breast milk is a vehicle for HIV transmission, the milk itself exhibits a strong protective effect against infection. Breastfed babies ingest 100,000 - 100,000,000 maternal cells every day via breast milk; what remains largely unclear is the contribution of these cells to the milk’s anti-viral qualities. A large study has been undertaken to isolate cells from human milk in order to measure the ability of these cells to engulf and destroy HIV by a mechanism known as phagocytosis. Over 50 samples of breast milk obtained from healthy women have been analyzed. Phagocytosis of HIV was detected in all samples. Activity did not appear to correlate with stage of lactation. Various cell types known for phagocytic capacity were identified and measured, including granulocytes, monocytes, macrophages, and dendritic cells. All samples exhibited strong granulocyte activity.These data further demonstrate that phagocytosis of HIV by immune cells from breast milk can be measured. This information will be critical for design of therapeutic vaccines capable of reducing the likelihood of mother-to-child transmission of HIV in areas where breastfeeding is essential.
Learning Objectives:
Objective 1: Explain how breast milk is both a vehicle for mother-to-child transmission of HIV and also protects against transmission;
Objective 2: List the cellular components of human breast milk;
Objective 3: Describe how maternal cells can be isolated from breast milk and used for analysis of their anti-viral functions.