Submitted to: Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2004
Publication Date: 2/14/2005
Citation: Butler, J.E., Wertz, N., Sun, J., Sacco, R.E. 2005. Comparison of the expressed porcine vbeta and jbeta repertoire of thymocytes and peripheral t-cells. Immunology. 114:184-193. Interpretive Summary: There is a lack of basic information on porcine white blood cell subsets at the molecular level. In the present studies reported, we have provided basic information on one specific subset of white blood cell known as the T lymphocyte. We have compared the results of our data to previously published work on human T lymphocytes and previously published results for a subset of pig T lymphocytes. Our results show that the relative gene usage of the particular receptor molecule we have observed in pigs resembles that of humans.
Technical Abstract: Transcripts of >300 complete TCRBeta V-D-J rearrangements recovered from porcine thymocytes and peripheral T cells were compared. We identified 19 groups (families) of porcine VBeta genes in seven supergroups and provisionally named 17 groups based on their sequence similarity with recognized human VBeta gene families. TRBV4S, 5S, 7S and 12S accounted for > 80% of all VBeta usage and usage of these groups by thymocytes and peripheral T cells was highly correlated. However, members of TRBV groups 2S, 9S and 15S were only recovered in the periphery. No TRBV group was uniquely expressed in significant numbers in thymocytes. Usage of JBeta segments from the 5' D-J-C duplicon in thymocytes and peripheral T cells, directly correlated with their 5' position in the locus and JBeta1.1; 1.2 and 1.3 accounted for ~/ 35% of all JBeta usage. This contrasts with usage of the JBeta2 segments in that JBeta2.4, 2.5 and 2.7 accounted for > 30% of JBeta usage by T-cells and JBeta 2.4 and 2.5 accounted for > 25% of JBeta usage by thymocytes. JBeta 2.7 was three-fold more frequent among T cells than thymocytes. In T cells, the major VBeta groups were preferentially recombined to JBeta1.2, 2.5 and 2.7 but JBeta 2.7 was seldom recombined to the major VBeta groups used by thymocytes. JBeta1.4 was heavily used by TRB4S, but not by TRBV7S or 12S. TBRV21S seldom used JBeta2 segments. These studies show that unlike porcine heavy chain VH genes, the occurrence and relative usage of porcine TCR VBeta groups, resembles that of humans. Thus, highly homologous genes systems can individually diverge within a species.