A heterophile carbohydrate moiety common to mammalian IgM and erythrocytes detected by chicken IgM antibody

Carbohydrates as recognition molecules in infection and immunity

Consideration of host-parasite interactions encompasses a wide range of phenomena from adhesion to epithelial surfaces to interactions with cells of the immune system. This review focuses on the role of carbohydrates as recognition molecules in these complex interactions. The abundant glycoproteins and glycolipids of cell surfaces of both prokaryotic and eukaryotic cells have the ability to exist in a variety of spatial configurations through alpha- and beta-linkages and the formation of branched structures. This ability carries with it the opportunity of acting as informational molecules greater than that possible for proteins or nucleic acids. The blood group substances are probably the best characterized of these carbohydrate containing molecules. Whilst at present a detailed understanding of the importance of these molecules in host-parasite interaction is lacking, the material covered in this discussion emphasizes the way in which carbohydrate based recognition has been shown to be involved and may provide the basis for further understanding.

Effect of hydrocortisone on immune system of the lizard, Chalcides ocellatus. II. Differential action on T and B lymphocytes

Lymphocytes of thymus, spleen, peripheral blood (PB) and bone marrow (BM) collected from adult lizards, Chalcides ocellatus were cultured for 24 hr in the presence of 10(-3)M hydrocortisone acetate (HC) in order to assess the effect of in vitro HC on lizard T and B cell viability. The results indicated that HC induced stepwise, time-dependent mortality of the majority of thymocytes carrying T cell specific antigen(s) (TSA), 30-50% of T cells of spleen, PB and BM, and of a proportion of splenic B lymphocytes. Administration of 1 mg/g body weight HC to adult Ch. ocellatus lead to depletion of all TSA+ thymocytes. In contrast, T lymphocytes in the peripheral lymphoid compartments revealed both sensitivity and resistance to HC; similarly, B lymphocytes constituted susceptible and resistant subpopulations.

Surface marker for hemopoietic and endothelial cell lineages in quail that is defined by a monoclonal antibody

A mouse monoclonal antibody raised in response to quail immunoglobulin mu chain was found to exhibit a broad reactivity towards hemopoietic and endothelial cells in the quail (Coturnix coturnix japonica). Indirect immunofluorescence assays were performed at several stages of embryonic development and until 3 weeks after hatching, on either isolated cells or tissue sections. They revealed that the defined surface marker, referred to as MB1, (i) is expressed early on both intra- and extraembryonic hemopoietic stem cells and is transmitted to the whole progeny of these precursors, with the exception of mature erythrocytes, and (ii) is a constant feature of the endothelial cell surface throughout ontogenesis and adult life. In addition, this epitope is included in several soluble plasma components. MB1 expression was not detected in chicken tissues, and this characteristic was used to confirm its lineage restriction in quail-chicken chimeras. We stress the value of this species- and lineage-specific marker in study of the development of the hemopoietic and endothelial cell families, with special reference to their possible early common embryonic origin.

Acquired heterophile antigens on the surface of human cell lines

Chicken IgM antibodies raised against sheep erythrocytes (SE) reacted with a heterophile carbohydrate antigen designated as "HC". This antigen was visualized by SE rosette formation with antibody-sensitized and formaldehyde-fixed target cells. Cells from eight lymphoblastoid lines and ten lines of diverse histogenetic origin all expressed HC on their surface to a greater or lesser degree when grown in fetal calf serum (FCS). Lymphoblastoid cell lines, HSB2 and Namalva, lost most of their HC antigen after three cell divisions when grown in medium which contained normal human serum (NHS) instead of FCS. The acquired origin of HC was demonstrated by the conversion of HSB2-HC- into HSB2-HC+ cells after incubation in the presence of FCS or fetuin for 18 h at 37 degrees C. The acquisition of HC antigen depended on the concentration of fetuin as well as the time and temperature of incubation. The presence of NHS in the culture medium reduced the degree of HC incorporation. The level of HC expressed on the cell surface was reduced by treating HSB2 cells with sodium periodate but not by proteolytic enzymes. Competitive inhibition with hog blood group substance and sheep IgG suggested similar specificity of HC on target cells which had been sensitized with either fetuin or sheep IgM (Eur. J. Immunol. 1977.7:204). The avidity of chicken antibodies to HC in either of these systems was several orders of magnitude lower than the binding to SE.