Developmental pathways of gammadelta T cells are still unknown, largely because of the absence of recognized lineage-specific surface markers other than the TCR. We have shown that porcine gammadelta thymocytes can be divided into 12 subsets of the following two major groups: 1) CD4(-) gammadelta thymocytes that can be further subdivided according to their CD2/CD8alphaalpha phenotype, and 2) CD4(+) gammadelta thymocytes that are always CD1(+)CD2(+)CD8alphabeta(+) and have no counterpart in the periphery. In this study, we have analyzed gammadelta thymocyte subsets with respect to behavior during cultivation, cell cycle status, and lymphocyte-specific transcripts. The group of CD4(-) gammadelta thymocytes gives rise to all gammadelta T cells found in the periphery. Proliferating CD2(+)CD8(-)CD1(+)CD45RC(-) gammadelta thymocytes are a common precursor of this group. These precursors differentiate into CD2(+)CD8alphaalpha(+), CD2(+)CD8(-), and CD2(-)CD8(-) gammadelta T cell subsets, which subsequently mature by loss of CD1 and by eventual gain of CD45RC expression. In contrast, the group of CD4(+) gammadelta thymocytes represents transient and independent subsets that are never exported from thymus as TCRgammadelta(+) T cells. In accordance with the following findings, we propose that CD4(+)CD8alphabeta(+) gammadelta thymocytes extinguish their TCRgammadelta expression and differentiate along the alphabeta T cell lineage program: 1) CD4(+) gammadelta thymocytes are actively dividing; 2) CD4(+) gammadelta thymocytes do not die, although their numbers decreased with prolonged cultivation; 3) CD4(+) gammadelta thymocytes express transcripts for RAG-1, TdT, and TCRbeta; and 4) CD4(+) gammadelta thymocytes are able to alter their phenotype to TCRalphabeta(+) thymocytes under appropriate culture conditions.

• MeSH
• antigeny CD1 metabolismus   MeSH
• antigeny CD2 metabolismus   MeSH
• antigeny CD45 imunologie   metabolismus   MeSH
• apoptóza MeSH
• buněčná diferenciace imunologie   MeSH
• buněčný rodokmen imunologie   MeSH
• CD4-pozitivní T-lymfocyty imunologie   metabolismus   MeSH
• CD8-pozitivní T-lymfocyty imunologie   metabolismus   MeSH
• fenotyp MeSH
• genetická transkripce genetika   MeSH
• kultivované buňky MeSH
• pohyb buněk MeSH
• prasata imunologie   MeSH
• receptory antigenů T-buněk gama-delta genetika   imunologie   MeSH
• thymus cytologie   imunologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny CD1 MeSH
• antigeny CD2 MeSH
• antigeny CD45 MeSH
• receptory antigenů T-buněk gama-delta MeSH

The developing porcine fetus offers an excellent opportunity for the study of lymphocyte development. Studies on B cell, alphabeta T cells and gammadelta T cells in the last decade have expanded our knowledge of lymphocyte development in pigs. These studies have revealed several interesting differences between swine, mice and humans. For example, porcine peripheral lymphocytes include CD4+CD8+ alphabeta T cells and an abundance of gammadelta T cells that may even prevail over the alphabeta population. There are numerous CD2- gammadelta T cells in the blood and a large number of CD8alphaalpha-bearing cells that include NK cells, conventional gammadelta and alphabeta T cells. All porcine B lymphocytes are CD25(lo) and sIgM+ B cells may differ in the expression of CD2 antigen. Unlike mice, porcine B cells appear approximately 2 weeks before T cells and progenitors undergo VDJH rearrangement at 20th day of gestation (DG20) in the yolk sac and DG30 in the fetal liver before consummating high level lymphogenesis in the bone marrow after DG45. Early B cells show an unexpectedly high proportion of in-frame rearrangements, undergo switch recombination in thymus on DG60 and use N-region insertion from the time of the earliest VDJ rearrangement. The genomic repertoire of VH, DH and JH genes is small compared to mice and humans and swine appear to depend on junctional diversity for the majority of their repertoire. The limited VH repertoire of swine contrasts sharply with the porcine TCRbeta repertoire, which is extensive, extraordinarily conserved and nearly identical to that in humans. Therefore, swine present an example of two highly related receptor systems that have diverged in the same species.

• MeSH
• B-lymfocyty cytologie   imunologie   MeSH
• buněčná diferenciace MeSH
• lidé MeSH
• lymfocyty cytologie   imunologie   MeSH
• lymfopoéza MeSH
• myši MeSH
• prasata embryologie   imunologie   MeSH
• T-lymfocyty - podskupiny cytologie   imunologie   MeSH
• těhotenství MeSH
• vývoj plodu imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• srovnávací studie MeSH

In this report, we describe 12 subpopulations of porcine gammadelta thymocytes based on their expression of CD1, CD2, CD4, CD8- isoforms and CD45RC. Our data suggest that gammadelta thymocytes can be divided into two major families: (a) one large family of CD4-gammadelta thymocytes that could be further subdivided according to the CD2/CD8alphaalpha phenotype and (b) a small family of CD4+ gammadelta thymocytes bearing CD8alphabeta and possessing certain unusual features in comparison with other gammadelta thymocytes. Maturation of gammadelta thymocytes within the CD4- family begins with proliferation of the CD2+ CD8- CD1+ CD45RC- gammadelta common precursor. This developmental stage is followed by diversification into the CD2+ CD8alphaalpha+, CD2+ CD8- and CD2- CD8- subsets. Their further maturation is accompanied by a loss of expression of CD1 and by increased expression of CD45RC. Therefore, individual subsets develop from CD1+ CD45RC- through CD1- CD45RC- into CD1- CD45RC+ cells. On the other hand, gammadelta thymocytes within the CD4+ family bear exclusively CD8alphabeta, always express CD1, but may coexpress CD45RC. These cells have no counterpart in the periphery. Our observations suggest that all peripheral CD8+ gammadelta T cells express CD8alphaalpha and that two subsets of these cells differing in major histocompatibility complex II expression, occur. We propose that one subset acquires CD8alphaalpha in the thymus while the second acquires CD8alphaalpha as a result of stimulation in the periphery.

• MeSH
• antigeny CD1 imunologie   MeSH
• antigeny CD2 imunologie   MeSH
• antigeny CD45 imunologie   MeSH
• antigeny CD8 imunologie   MeSH
• buněčná diferenciace imunologie   MeSH
• buněčné dělení imunologie   MeSH
• CD antigeny imunologie   MeSH
• CD4-pozitivní T-lymfocyty imunologie   MeSH
• CD8-pozitivní T-lymfocyty imunologie   MeSH
• histokompatibilita - antigeny třídy II imunologie   MeSH
• imunofenotypizace metody   MeSH
• kultivované buňky MeSH
• modely u zvířat MeSH
• prasata MeSH
• receptory antigenů T-buněk gama-delta imunologie   MeSH
• slezina cytologie   imunologie   MeSH
• T-lymfocyty - podskupiny imunologie   MeSH
• thymus cytologie   embryologie   imunologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny CD1 MeSH
• antigeny CD2 MeSH
• antigeny CD45 MeSH
• antigeny CD8 MeSH
• CD antigeny MeSH
• histokompatibilita - antigeny třídy II MeSH
• receptory antigenů T-buněk gama-delta MeSH