Plasmodium falciparum-specific human T cell clones: recognition of different parasite antigens.

T lymphocyte clones specific for malarial (Plasmodium falciparum) blood stage antigens were obtained from acutely infected patients or from donors living in a malaria-endemic area of West Africa. Thirty-four clones carrying the CD4 antigen, and one CD8+ clone, were tested in a proliferation assay for their capacity to recognize P. falciparum isolates of different geographical origins.

Clones of B lymphocytes in individual follicles of the bursa of Fabricius.

To discover whether individual bursal follicles can contain clones of B lymphocytes, we estimated the numbers of lymphoid cell precursors populating single follicles in two types of chicken chimera. The first type was produced by establishing parabiotic connections between blood vessels of embryo chorioallantoic membranes. Under these conditions, and most likely during normal development, most follicles are populated by more than one, but less than ten, precursor cells.

A monoclonal antibody recognizes an epitope common to an avian-specific nuclear antigen and to cytokeratins.

X3, a monoclonal antibody of unusual specificity, is described. This antibody reacts with one or more cytokeratin polypeptides and also reacts with an avian (chicken, quail) nuclear antigen that appears to be present in all cell types (chicken) tested, although with variable staining pattern and intensity. This antigen is distinct from the cytokeratins but does have an epitope in common with this class of proteins.

Monoclonal antibodies against chicken lymphocyte surface antigens.

Spleen and lymph node cells of BALB/c mice, previously immunized with chicken thymic or bursa cells, were fused with Sp2/0-Ag14 mouse myeloma cells. Hybridomas from two fusions were selected on the basis of reactivity of their secreted antibodies towards thymic or bursal tissues in an indirect immunofluorescence assay. Four monoclonal antibodies reacting with different cell surface proteins of chicken lymphocytes were characterized, as follows.

Monoclonal antibody which recognizes a common antigenic determinant on intermediate filament proteins, actin, and myosin.

A monoclonal antibody is described which reacts with the intermediate filament proteins vimentin, desmin, keratins, actin, and myosin. This is the first report of an epitope common to intermediate filament proteins and myosin. X1, the wide-spectrum monoclonal antibody in question, was isolated in the course of screening monoclonal antibodies to chicken thymocytes.

Quantitative aspects of the nonspecific humoral immune response to sheep erythrocytes.

The kinetics and magnitude of the nonspecific humoral immune response was studied at the cellular level in mice immunized with sheep erythrocytes (SRBC). Intravenous injection of the antigen evoked, in addition to a specific anti-SRBC response, a nonspecific response of all immunoglobulin (Ig) classes and subclasses. This nonspecific response peaked on day 4 or 5 after immunization, irrespective of the Ig class.

Immunoglobulin isotype expression. II. Frequency analysis in mitogen-reactive B cells.

The frequency of lipopolysaccharide (LPS)-reactive B cells developing into clones that secrete the various immunoglobulin (Ig) classes has been determined in vitro, in cells from BALB/c mice, under culture conditions which detect all growth-inducible cells. Secretion of the different Ig classes was assessed in the protein A plaque assay for Ig-secreting, plaque-forming cells by using developing antisera specific for either IgM, IgG1, IgG2a, IgG2b, IgG3 or IgA. In all lymphoid organs tested (spleen, bone marrow, mesenteric lymph nodes and thoracic duct), a considerable proportion of all B cells (5-20%) was induced by LPS to yield a clone of IgM-secreting cells.

Genetic control of lipopolysaccharide-induced mobilization of CFUs. Dissociation between early and delayed mobilization of CFUs in complement C5-deficient mice and LPS non-responder mice.

Lipopolysaccharide (LPS)-induced mobilization of CFUs from haemopoietic tissues into the circulation has a biphasic pattern. The first rise occurs within 30 min of LPS injection, the second 4-7 days later. This second rise coincides with an increase of the CFUs number in the spleen from about 3000 to about 50,000.

Frequency analysis of immunoglobulin V-gene expression and functional reactivities in bone marrow B cells.

Frequency of immunocompetent B cells in bone marrow has been determined in vitro under culture conditions that allow the development in vitro under culture conditions that allow the development of every growth-inducible B cell into a clone of IgM-secreting PFC. Three limiting dilution culture systems were employed: a specific helper assay with SRBC as antigen and using activated T helper cells, a nonspecific helper assay using Con A-induced factors as a source of help, and polyclonal activation with LPS. From unseparated, normal C57BL/6J bone marrow 1 in 2200 to 1 in 2820 B cells were induced to form a clone of PFC to SRBC in each of the 3 systems.

Proliferative response of H-2 incompatible leukocytes to an Abelson virus-induced lymphoma cell line apparently not expressing Ia-antigens.

The proliferative response of normal lymph node cells from different mouse strains to an Abelson virus-induced leukemic cell line (MLVA) in mixed leukocyte culture (MLC) has been investigated. MLVA leukemic cells do stimulate a specific response and the stimulating determinants are controlled, most likely, by genes in the K-end of the H--2 complex. However, using two different anti-Ia sera and different assay systems, we were unable to detect the expression of Ia-antigens on MLVA.

Glyoxalase I polymorphism in the mouse: a new genetic marker linked to H-2.

Two electrophoretically distinct variants of glyoxalase I (Glo-I) are present in mouse (Mus musculus). The two forms are controlled by two codominant alleles Glo-1a (common) and Glo-1b (rare) at an autosomal locus. A linkage study showed that Glo-1 maps at approximately 3 centimorgans from the Ss locus of the H-2 histocompatibility region.