Related Experiment Videos
Immunoglobulin and cytokine production by neonatal lymphocytes
1Department of Paediatrics and Child Health, University of Manitoba, Winnipeg, Canada.
Insights
Cord blood B cells show limited growth and antibody production compared to adult cells. This is due to both intrinsic B cell limitations and reduced T cell support, impacting immune responses in newborns.
Area of Science:
- Immunology
- Developmental Biology
Background:
- Cord blood B cells are crucial for neonatal immunity.
- Understanding their functional capacity is essential for assessing infant immune responses.
Purpose of the Study:
- To investigate the growth and differentiation potential of cord blood B cells.
- To compare cord blood B cell responses to adult B cells.
- To assess the role of T cell-derived cytokines in B cell development.
Main Methods:
- T cell-depleted cord blood and adult B cell populations were cultured.
- Cells were stimulated with cytokines (IL-2, IL-4, IL-6) and anti-mu antibodies.
- Activation was also performed using Staphylococcus aureus Cowan I (SAC).
- T cell supernatants were analyzed for lymphokine content and B cell stimulatory activity.
Main Results:
- Cord blood B cells proliferated in response to IL-2 and IL-4 but showed a diminished response to IL-2 upon anti-mu stimulation compared to adult cells.
- IL-6 enhanced IgM synthesis, while IL-2 decreased it in cord blood B cells.
- Cord blood B cells produced significantly less IgM than adult B cells after SAC activation, irrespective of cytokine addition.
- No IgG or IgA production was observed from cord blood B cells.
- Cord blood T cells produced lower levels of IL-2 and IL-6 and exhibited reduced B cell stimulatory activity compared to adult T cells.
Conclusions:
- Cord blood B cells exhibit a limited capacity for growth, differentiation, and antibody production (IgM, IgG, IgA).
- This functional limitation stems from both intrinsic B cell defects and reduced production of essential B cell stimulatory lymphokines by cord blood T cells.
- These findings highlight potential vulnerabilities in the neonatal immune system's ability to mount robust antibody responses.
Abstract:
Growth and differentiation of cord blood B cells were studied using T cell-depleted populations. In the absence of in vitro activation, cord blood B cells proliferated in response to cytokines including interleukin-2 (IL-2) and interleukin-4 (IL-4); anti-mu-stimulated cord B cells had a lesser response to IL-2 than adult cells. IgM synthesis by cord blood B cells was enhanced by interleukin-6 (IL-6) and decreased by IL-2. In cultures activated by Staphylococcus aureus Cowan I (SAC), cord blood B cells produced lesser increases in IgM than adult B cells regardless of the cytokine added. Cord blood B cells produced no IgG or IgA with any cytokine preparation with or without SAC activation. Supernatants of cord blood T cells pulse-stimulated with phytohaemagglutinin and phorbol myristate acetate contained less IL-2 and IL-6 and had less growth and differentiation activity than adult T cell supernatants. The results confirm a limited cord blood B cell response and also suggest a limitation in production of B cell stimulatory lymphokines by cord blood T cells.