The CD39 molecule defines distinct cytotoxic subsets within alloactivated human CD8-positive cells.

Lymphocyte activation induces or increases the expression of several surface structures, none of which is characteristic of an activated cell subset. In particular, structures such as CD45RO, CD25, CD26, CD49b, CD54, CD71 are expressed by the vast majority of lymphocytes at various times following in vitro activation. CD39 molecules were originally identified on activated B lymphocytes and have recently been described on activated T cell clones.

Increased surface expression of a newly identified 150-kDa dimer early after human T lymphocyte activation.

Lymphocyte activation induces or increases the expression of several surface structures, some of which are directly involved in cell growth such as receptors for IL-2 or transferrin. In order to identify new structures characteristic of activated lymphocytes, we developed a series of mAb against functionally defined human T cell clones. In the present study we report the isolation of a mAb termed BB18 recognizing, at the cell surface, a novel 150-kDa glycoprotein dimer whose expression on T lymphocytes increases readily after their activation with various stimuli including lectins.

Plasmodium falciparum: isolation and characterization of a 55-kDa protease with a cathepsin D-like activity from P. falciparum.

Native electrophoresis followed by imprint digest method using hemoglobin as substrate allowed the detection of parasite hemoglobinase activity at acidic pH (3.9 to 5). This protease was inhibited specifically by pepstatin A and insensitive to other protease inhibitors.

The SCID mouse.

Numerous investigations of the mammalian hematopoietic system in normal and pathologic states have been facilitated by the study of genetically determined immunologic dysfunctions in experimental animals. This article focuses on the scid mutation of the mouse (SCID mouse) that causes severe defects in the development of the immune system. The mutation appears to impair the recombination of antigen receptor genes, causing in the SCID mice a lack of functional T and B lymphocytes.

[The marmoset in biomedical research. Value of this primate model for cardiovascular studies].

Because of its small size, low cost of maintenance, breeding capabilities in captivity, the marmoset, a New World monkey, appears well suited for clinical and fundamental investigations. The contribution of this laboratory animal in the main areas of biomedical research is succinctly described: viral oncology, infections diseases, immunology, reproduction, toxicology and teratology, odontology, behaviour and neuro-psychopathology. Emphasis is put upon the exceptional interest of the use of marmoset as a biological model in cardiovascular studies.

Effect of passive transfer of human anti-myelin-associated glycoprotein IgM in marmoset.

Adult and one week old marmosets were injected intravenously within a one month period or intraperitoneally within a 6 week period respectively, with monoclonal IgM having an anti-myelin associated glycoprotein antibody activity. No clinical or electrophysiological abnormalities could be detected in experimental animals. However, indirect immunofluorescence studies showed IgM deposition in close contact to myelin sheaths.

Production and characterization of a mouse monoclonal antibody to the glycolipid asialo-GM1.

The glycosphingolipid asialo-GM1 (aGM1) is a true differentiation antigen of murine lymphoid cells. This glycolipid is highly immunogenic in the rabbit, but the antisera produced shows some cross reactivity with GM1, the naturally occurring sialylated derivative of aGM1. In the present study we examined the ability to raise anti-aGM1 antisera in the mouse.

Interferon inhibits Aspergillus fumigatus growth in mice: an activity against an extracellular infection.

Prophylactic treatment of mice with interferon (IFN) or polyinosinic-polycytidylic acid [poly(I:C)], an IFN inducer, provided significant protection against an extracellular infection by Aspergillus fumigatus in both Swiss and Swiss athymic nude mice. Tunicamycin (TM) treatment inhibits the antifungal activity of IFN and poly(I:C) in these mice. Anti-asialo GM1 or TM [both inhibitors of natural killer (NK) cell function] treatment enhance the severity of A.

Marmoset red blood cell receptor for membrane-associated complement components is not related to human CR1: partial characterization of the C3-binding proteins responsible for the spontaneous rosette formation between marmoset red blood cells and human leukocytes.

Cells from all the human B-lymphoblastoid cell lines tested and most human monocytes form rosettes with marmoset red blood cells (MaRBC). Because previous reports suggested the involvement of complement components in this phenomenon, the mechanism of rosette formation and the eventual similarities between the MaRBC receptor and the CR1 receptor present on human erythrocytes have been analyzed herein. The binding of MaRBC to human leukocytes strongly differs from the immune adherence phenomenon: rabbit anti-human CR1 did not react with MaRBC and the MaRBC receptor-binding activity is Ca2+-dependent.

Characterization of a human lymphoblastoid cell line permanently modified by simian foamy virus type 10.

Simian Spumavirinae serotype, SFV10, of a Papio cynocephalus baboon, was used to infect a human lymphoblastoid cell line, LV2. Permanent growth and morphological alterations of infected cells occurred, even though no viral particles were detected. Evidence for the presence of viral genomes in the modified cell line is provided indirectly from immunological studies and induction experiments followed by coculture procedures.

Presence of pH2-sensitive circulating interferon among Callithrix jacchus marmosets.

Significant and relatively stable levels of serum-interferon were demonstrated in a Callithrix jacchus population. This circulating interferon was acid-sensitive in all cases, classifying it as immune or "gamma-type" interferon. Our results in these hematopoietic chimeras suggest that the presence of immune-type or at least pH 2-sensitive interferon could be related to the presence of two allogenic lymphocyte populations in each marmoset.

Analysis of HLA class I genes with restriction endonuclease fragments: implications for polymorphism of the human major histocompatibility complex.

Cellular DNA from HLA-typed individuals was digested with the restriction endonucleases HindIII, EcoRV, and EcoRI. The separated restriction endonuclease fragments were hybridized with a HLA class I cDNA probe by using the Southern transfer technique. Digestion of cellular DNA with HindIII generated 22 restriction endonuclease fragments, 11 of which showed polymorphism for presence or absence in a population sample.

[Polymorphism of HLA genes: I. Demonstration of a close correlation between DNA fragments determined by BglI restriction enzyme and HLA class I antigens].

Description of DNA fragments associated to HLA class I gene is possible by using restriction enzymes which determine these fragments and specific DNA probes which permit their detection. In one family, with a child presenting a recombination between HLA-A and C, six fragments determined by the enzyme BglI were found to be polymorphic. The informative fragments segregate with HLA, either with a whole haplotype or with one of the two recombinant segments of the HLA complex.

Analysis of DR-like molecules on a marmoset Epstein-Barr virus-induced cell line using a monomorphic anti-human HLA-DR monoclonal antibody.

Mouse anti-HLA D region-related (DR) monoclonal antibodies have been found to cross-react with peripheral blood leukocytes from one primate species, the common marmoset (Callithrix jacchus). Immunoprecipitates of radioactively labeled cells extracted from a marmoset Epstein-Barr virus-induced cell line were analyzed by one- and two-dimensional gel electrophoresis and compared with the DR antigens of a human lymphoblastoid B cell line. Two chains of estimated molecular weights of 34 000 (alpha) and 28 000 (beta), similar to the human alpha and beta chains, have been observed in marmoset immunoprecipitates.

Monoclonal antibodies as a tool for phylogenetic studies of major histocompatibility antigens and beta 2-microglobulin.

The cross-reactivity of several monoclonal antibodies recognizing monomorphic determinants of human HLA-A, B, C, and DR antigens and human beta 2-microglobulin (beta 2m) has been studied on peripheral blood leukocytes in 24 different species. An monoclonal HLA-A-, B-, and C-specific antibody and four monoclonal HLA-DR-specific antibodies cross-reacted with cells from all the primate species tested. Furthermore, antibodies HLA-DR-specific were positive with peripheral blood leukocytes (PBL) from cows, goats, sheep, horses, and dogs.

The expression and relation of HLA, beta2-microglobulin and receptor for marmoset red blood cells on man/mouse and man/Chinese hamster hybrid cells.

The expression of HLA, human and mouse beta2-microglobulin (beta2m), P red blood cell antigen and a receptor for marmoset red blood cells (MaRBC) were studied on 18 man/mouse and man/Chinese hamster hybrids. A positive correlation was found between the expression of HLA, P, and the receptor for MaRBC, which we interpret as a possible synteny between these different loci. We studied 3 hybrid clones where HLA antigens are still expressed despite the absence of human beta2m and where redistribution experiments demonstrate that HLA is associated with mouse beta2m.

Failure to suppress theta antigenic expression in progeny derived from pre-immunized maternal recipients.

One possible theory concerning the success of the fetus as an allograft has been attributed to maternal modification of foreign fetal antigenic expression. In this respect progeny derived from pre-immunized maternal mouse recipients, have been examined for any modification (reduction) of corresponding theta antigen determinants. Two major groups of mice were examined.

The innate resistance of CBA mice to endogenous murine leukaemia virus infection.

The incidence of lymphomata in CBA mice is low and furthermore is unaltered by transplantation at the early blastocyst stage and being born from the lymphoma-prone AKR. The number of C-type murine leukaemia virus particles in CBA derived in this manner and milk-fostered by AKR mice in no way differs from normal CBA. The results suggest that the oncogenic Gross virus does not pass through either the transplacental or transmammary routes, or alternatively that viral replication in the CBA was in some way inhibited.