Compartments within the lymph node cortex of calves and adult cattle differ in the distribution of leukocyte
G Gunnes1, C M Press, A Tverdal
1Department of Morphology, Genetics and Aquatic Biology, Norwegian College of Veterinary Medicine, Oslo, Norway.
Insights
Calf lymph nodes show fewer B-cells and T-cells compared to adult cattle, potentially due to maternal immunity. Computer analysis revealed differences in leukocyte distribution, highlighting early immune development in young animals.
Area of Science:
- Immunology
- Veterinary Pathology
- Comparative Anatomy
Background:
- Leukocyte populations in lymph nodes are crucial for immune responses.
- Understanding immune development in young animals is vital for health.
- Passive transfer of maternal immunity can influence neonatal immune function.
Purpose of the Study:
- To investigate leukocyte distribution in the distal jejunal lymph nodes of calves and adult cattle.
- To compare immune cell populations between young and adult cattle using advanced analytical techniques.
- To explore the impact of early life immune factors on lymph node architecture.
Main Methods:
- Immunohistochemistry with monoclonal antibodies to identify leukocyte populations.
- Computer-assisted morphometric analysis for quantitative assessment of cell distribution.
- Semi-quantitative estimation of staining areas in histological sections.
Main Results:
- Calves exhibited significantly fewer B-cells and CD4+ cells in the outer cortex and fewer T-cells (CD4+, CD8+, gamma delta T-cells) in the deep cortex compared to adults.
- Increased CD1+ populations (interdigitating cells) were observed in calf lymph nodes, suggesting antigen exposure.
- Antigen-presenting cell populations (pan MHC II+, MHC II DQ+) were elevated in calf lymph nodes but not significantly different from adults.
Conclusions:
- Reduced lymphocyte populations in calves may result from immunosuppression via maternal antibody transfer.
- The presence of B-cell follicles in the deep cortex indicates ongoing immune cell differentiation.
- Computer-assisted analysis is a powerful tool for studying leukocyte populations in lymph node microenvironments.
Abstract:
The combination of an immunohistochemical technique and a panel of monoclonal antibodies was used to investigate the presence of leukocyte populations in the distal jejunal lymph node of 3-4 week old calves and adult cattle. The application of computer-assisted morphometric analysis enabled information to be obtained on the distribution of leukocyte populations in lymphoid compartments of the lymph node cortex. Semi-quantitative estimates of the areas of staining in histological sections showed that calves possessed significantly fewer B-cells and CD4+ cells in the outer cortex and significantly fewer T-cells (CD4+, CD8+ and gamma delta T-cells) in the deep cortex. These findings were interpreted to be a possible consequence of immunosuppression resulting from the passive transfer of maternal immunity in colostrum. The presence of some B-cell follicles in the region defined as the deep cortex suggested the on-going differentiation of this predominantly T-cell compartment. The larger presence of interdigitating cells (IDC) in the deep cortex of calves than adults was suggested by significantly larger CD1+ populations and it was argued that this could be the result of the confrontation with exogenous antigen faced by calves in early postnatal life. Antigen presenting populations, pan MHC II+ and MHC II DQ+ populations, were increased in all compartments of calf lymph nodes but were not significantly different from the populations in adult lymph nodes. Variance component analysis of the data generated in the present study showed that the image analysis technique was an effective and statistically powerful approach to investigate leukocyte populations within the specific microenvironments of the lymph node.
