Committed precursors of B and T lymphocytes in chick embryo bursa of Fabricius, thymus, and bone marrow

Abstract

Lymphocyte precursors in bursa of Fabricius, thymus and bone marrow (BM) of chick embryos were studied at different stages of incubation over 12-21 days, and for their state of commitment to B or T cell lines of development. Cell suspensions were fractionated on albumin gradients to remove nonlymphoid cells and incubated in vitro with bursopoietin, a specific inducer of B cells, or crude chicken thymus extract, a specific inducer of T cells, or ubiquitin, a nonspecific inducer. Precursors were identified by increases in numbers of cells bearing surface alloantigens as determined by immunofluorescence, either Bu-1 (specific to B cells) or Th-1 (specific to T cells). Precursors inducible to Bu-1+ cells were found in bursal cells and BM cells from all age groups but not in thymic cells. Precursors inducible to Th-1+ cells were found in thymic preparations and BM cells at all ages, but in significant numbers in bursa on day 12 only. Because B and T precursors were never found together in bursa or thymus, or only in very unequal amounts, it was concluded that precursors in these organs were not multipotential but were separately committed to one or other line of development. This argument did not apply to BM cells, for which other evidence was obtained. Bu-1+ cells were specifically induced in BM cells with bursopoietin and then removed by complement-dependent cytolysis wih anti-Bu-1 antiserum. When the remaining cells were incubated with ubiquitin, only Th-1+ cells were induced, showing that Bu-1 and Th-1 precursors were separately committed. Surface IgM was never induced on either bursal or BM lymphocytes. The Ia (or B-L) antigen was inducible on 12- to 21-day bursal cells, but could not be generated on BM cells until day 14 onwards. The pattern of occurrence of committed lymphocyte precursors in the developing chick embryo suggests that these cells are released into the circulation from both central lymphoid organs at their respective times of high lymphopoietic activity, and accumulate in the BM at least up to the time of hatching. Moreover, the presence of committed B precursors in bursa and committed T precursors in thymus at times and in quantities appropriate to the known features of avian lymphopoiesis leads us to conclude that in vitro induction is analogous to a true stage of in vivo B and T cell differentiation.

Histopathology, immunohistochemistry, in situ apoptosis, and ultrastructure characterization of the digestive and lymphoid organs of new type gosling viral enteritis virus experimentally infected gosling

“…Immune-competent avian cells of the specific immune system come from BF or thymus (Brand et al, 1983;Paramithiotis and Ratcliffe, 1994). In the course of embryonic development, precursors of these cells reach BF or thymus and these differentiante into B or T lymphocytes (Gobel, 1996;Sayegh et al, 2000;Ratcliffe, 2002).…”

Identification of cells secreting a thymostimulin-like substance and examination of some histoenzymatic pathways in aging avian primary lymphatic organs: II. Bursa of Fabricius

“…Since the discovery that the bursa was implicated in the differentiation of B-lymphocytes for humoral immunity (Chang et al, 1955;Glick et al, 1956;Papermaster and Good, 1962;Peterson and Good, 1965), attention was focused, on the one hand, on lymphoid cell populations (Ackermann and Knouff, 1959;Ackermann, 1962;Woods and Linna, 1965;Cooper et al, 1966;Toivanen et al, 1972 a,b;Toivanen et al, 1974;Back et al, 1973;Grossi et al, 1974;Grossi et al, 1976;Glick, 1974Glick, , 1983Glick, , 1995Glick et al, 1975;Eerola et al, 1982;Brand et al, 1983;Pink et al, 1985;Lassila, 1989;Nowak et al, 1990;Motyka and Reynolds, 1991;Petrini et al, 1991;Paramithiotis and Ratcliffe, 1993, 1994a,b, 1996Reynaud and Weill, 1993;Masteller and Thompson, 1994;Masteller et al, 1995;Paramithiotis et al, 1995;Obranovich and Boyd, 1996;Funk and Thompson, 1996) and, on the other hand, on the epithelial stroma providing the bursal microenvironment within which B-cell maturation and differentiation occurs.…”

“…The bursa is responsible for the maturation and differentiation of B-lymphocytes to produce humoral immunological responses. The other primary lymphoid organ, the thymus, instead, is responsible for the maturation and differentiation of T-lymphocytes, leading to cellular immunological responses (Dent and Good, 1965;Schaffner et al, 1974a;Le Douarin et al, 1984).The structure of the bursa has been described both during the ontogenetic period (Jolly, 1911a(Jolly, , 1914Cordier, 1969;Edwards et al, 1975;Le Douarin et al, 1975;Le Douarin et al, 1976;Le Douarin et al, 1984;Ritter and Lebacq, 1977) and during the posthatching period up to its involution (Jolly, 1911b(Jolly, ,1914Mc Connachie and Ruth, 1973;Glick, 1974Glick, , 1983Bellamy and Mohamed, 1982;Davenport and Allen, 1985).Since the discovery that the bursa was implicated in the differentiation of B-lymphocytes for humoral immunity (Chang et al, 1955;Glick et al, 1956;Papermaster and Good, 1962;Peterson and Good, 1965), attention was focused, on the one hand, on lymphoid cell populations (Ackermann and Knouff, 1959;Ackermann, 1962;Woods and Linna, 1965;Cooper et al, 1966; Toivanen et al, 1972 a,b;Toivanen et al, 1974;Back et al, 1973;Grossi et al, 1974;Grossi et al, 1976;Glick, 1974Glick, , 1983Glick, , 1995Glick et al, 1975;Eerola et al, 1982;Brand et al, 1983;…”

Age-related development and tissue distribution of T cell markers (CD4 and CD8a) in Chinese goose

“…Bursa of Fabricius (BF) is an organ peculiar and unique to birds, included in the gut-associated lymphoid tissue (GALT). Thymus and BF are considered as the primary lymphoid organs in birds, where lymphocytes develop and T-cell and B-cell receptor genes rearrange (Brand et al, 1983). After that, the lymphocytes migrate to secondary lymphoid organs such as spleen and caecal tonsil.…”