In lagomorphs, lymphocyte subset distributions and the importance of CD4(+) T cell levels has so far only been considered in the frame of rabbit disease models. In this study, the first assessment of CD4(+) T lymphocytes in peripheral blood cells in brown hares (Lepus europaeus L., 1758), a further leporid species using a cross-reactive rabbit anti-CD4 antibody in flow cytometry, is presented. In addition, the entire coding region of the hare CD4 gene (1380 bp) coding for a polypeptide of 459 amino acids has been sequenced. Using generalized least squares fitting by maximum likelihood (GLS) test, significantly (p=0.0095) higher CD4(+) T cell frequencies in males than in females and significantly (p=0.0001) higher frequencies for leverets (younger than 2 months of age) than for subadult and adult (older than 7 months of age) individuals were detected. No significant age influence, however, was found for subadult and adult hares. The study is particularly meant to provide a first step in establishing a toolbox for the assessment of the immune response in this leporid species.
Amino Acid Sequence Animals Antibodies Antigens, CD4/genetics Antigens, CD4/metabolism CD4-Positive T-Lymphocytes/cytology CD4-Positive T-Lymphocytes/immunology* CD4-Positive T-Lymphocytes/physiology* Female Hares/immunology* Male Molecular Sequence Data Rabbits Species Specificity Spleen/cytology