Phenotypic discrimination between thymic and extrathymic cd4−cd8− and cd4+cd8+ porcine t lymphocytes

Abstract

The composition of the T lymphocyte population in swine is special in that in addition to the CD4-CD8+ subpopulations, CD4-CD8- and CD4+CD8- and CD4+CD8+ subpopulations are prominent in the peripheral circulating as well as in the resident T lymphocyte pools. Since the same phenotypes are characteristic of thymic populations, it was asked whether the unusual distribution in swine may result from an emigration of thymic precursor phenotypes to the periphery. This explanation was refuted, as all thymic subpopulations were found to express CD1, albeit with differences in antigen density, whereas all extrathymic subpopulations lack CD1. The cellular distribution of CD2 in swine is without precedent among all species studied. Whereas in sheep and cattle the extrathymic CD4-CD8- subpopulation is known to entirely lack CD2 and to have a low propensity for homing to lymphoid tissues, the CD4-CD8- subpopulation in swine splits into CD2+ and CD2- subsets, both of which do reside in lymphoid tissues. While CD2+CD4-CD8- T lymphocytes are rare in the circulating pool, this subset accumulates in spleen and lymph nodes. This may indicate a role for CD2 in homing. Thus the species swine is immunologically unique, not only because of having CD1-CD2+CD4+CD8+ T lymphocytes in the periphery, but also with regard to subdivision and homing behavior of its CD4-CD8- T lymphocyte subpopulation.

Infection with classical swine fever virus: effects on phenotype and immune responsiveness of porcine T lymphocytes.

“…Almost all cells were CD2 + (Fig. 5 b, quadrants II and IV, 98 %) whereas the expression of CD1 antigen was heterogeneous with the highest CD1 antigen density on CD4 + CD8 + common thymocytes as described previously (Saalmu$ ller et al, 1989). DG T-cell phenotype and immune response to CSFV T-cell phenotype and immune response to CSFV Fig.…”

“…Target cells of the responder cell donor served as control. The measurements were performed on a dual-LASER FACStar plus (Becton Dickinson) essentially as described previously (Saalmu$ ller et al, 1989). The list mode data were processed for the respective figures using PC-lysis and Coreldraw software.…”

Membrane markers of the immune cells in swine: an update

“…One gene, a class I-like protein, with a 40 kDa heavy chain and a 12 kDa light chain [86], thus highly similar to human CD1a [55]. In both humans and pigs, CD1 group I (CD1 a, b and c) markers are expressed on cortical thymocytes, a fraction of B cells, thymic dendritic cells, some macrophages and Langerhans cells [147,167,183].…”

“…CD172a or CD8a, b, c, Table A) [122,160,174,251]. The lack of a letter means that no epitope was Swine CD2 (LFA2), a 50 kDa type I transmembrane glycoprotein 2 [167] is an adhesion molecule, the ligand of which LFA-3 (CD58) is found on many cells [34]. It is originally the sheep red blood cell receptor [167] and the anti-CD2 mAb block formation of the T-cell rosette [83].…”

“…The lack of a letter means that no epitope was Swine CD2 (LFA2), a 50 kDa type I transmembrane glycoprotein 2 [167] is an adhesion molecule, the ligand of which LFA-3 (CD58) is found on many cells [34]. It is originally the sheep red blood cell receptor [167] and the anti-CD2 mAb block formation of the T-cell rosette [83]. [92,168,239]; in addition, there is a large proportion of non-T (CD3 − ), non-B (sIg-) lymphocytes expressing CD2, (CD2 + CD4 − CD8 low ) and exhibiting a natural killer activity [239], as well as a subset of B lymphocytes albeit with CD2 at low level [196].…”