Cells In Peripheral Lymphoid Organs Research Articles

Many of the IgA producing plasma cells in murine gut are derived from self-replenishing precursors in the peritoneal cavity

Long term B lineage chimeras are used here to study the origin of plasma cells in the mouse. Chimeric mice are constructed by reconstituting lethally irradiated mice with peritoneal cells (PerC) and bone marrow cells from congenic pairs of mice differing in Igh-C allotype. All conventional B cells in these mice express the allotype of the bone marrow donor and nearly all Ly-1 B lineage cells express the allotype of the PerC donor. FACS analysis and immunohistology of these mice shows that virtually all (sig+) B cells in peripheral lymphoid organs are derived from the bone marrow donor. However, despite this overwhelming number of bone marrow-derived B cells in these animals, immunohistological staining of lymphoid organs and gut shows that nearly half of the IgM, IgG, and IgA plasma cells derive from the PerC donor. These data demonstrate that the peritoneal cavity contains a major reservoir of self-replenishing cells that play a significant role in the mucosal immune response. The possibility that these are B cells that belong to the Ly-1 B lineage is discussed.

Different subclass distribution of IgA-producing cells in human lymphoid organs and various secretory tissues.

A highly reproducible paired immunofluorescence staining method was used to map the relative distribution of IgA1- and IgA2-producing cells in peripheral lymphoid organs and various secretory tissues. Spleen, peripheral lymph nodes, and tonsils all contained a marked predominance (91 to 95%) of IgA1 immunocytes. However, striking variations were demonstrated among the secretory tissues with regard to the median proportion of IgA1-producing cells: nasal mucosa, 96%; lacrimal glands, 81%; major salivary glands, 66%; mammary glands, 63%; gastric and proximal small intestinal mucosa, 84 to 77%; ileum, 55%; and large bowel, 41%. Thus, IgA2 production is relatively enhanced mainly in the distal gut and in mammary and salivary glands, in that order.

Peanut agglutinin (PNA) binding as a marker for immature human B lymphocytes. Is bone marrow not the complete bursa-equivalent?

To investigate the nature of peanut agglutinin (PNA) binding cells in various human lymphoid tissues a double marker assay was performed using fluorescent PNA and rosetting with anti-mu or anti-delta coated ox red blood cells for detection of B cells or rosetting with sheep red blood cells for detection of T cells. In human bone marrow 60.5 +/- 8.6% of the surface mu+ve (smu+ve) B cells did bind PNA whereas only a small minority of the surface delta +ve (delta +ve) B cells (5.0 +/- 4.2%) and none of the T cells were PNA+ve. In peripheral blood most of the PNA+ve cells appeared to be monocytes. Only a small proportion of the smu+ve B cells (9.7 +/- 2.7%) and none of the s delta +ve B cells or T cells did bind PNA. Contrarily in tonsils a relatively high proportion of smu+ve B cells (33.2%) of s delta +ve B cells (26.3%) and of T cells (17.2%) were PNA+ve. These results indicate that PNA binding is also a marker for immature B cells. Moreover in human bone marrow at least two populations of B cells may be distinguished, an immature population of smu+ve, s delta-ve, PNA+ve B cells and a mature populations of smu+ve, s delta +ve, PNA-ve B cells, the latter probably representing recirculating B cells. We hypothesize that the first population comprises immature B cells, that leave the bone marrow in an early stage and complete the maturation to immunocompetent B cells in peripheral lymphoid organs like tonsils.

Localization of PNA-binding and nonbinding thymus cells in peripheral lymphoid organs

Thymus cells were labeled in vitro with FITC and injected into syngeneic recipients. In cell suspensions of lymphoid organs green cells were inspected for PNA receptors with double immunofluorescence. A striking preference of PNA-negative cells to localize in lymph nodes and the lymphoid compartment of the spleen was demonstrated. Incubation with anti-Ly sera revealed that Ly 1 + PNA-negative cells homed in popliteal lymph nodes and Peyer's patch but not in mesenteric lymph nodes.