Abstract: Methods are provided for treating a subject with for an intracellular pathogen infection, by administering an agent that reduces the binding of CD47 on a infected cell to SIRP? on a host phagocytic cell, in an effective dose for increasing the phagocytosis of infected cells.

Abstract: Methods are provided for treating a subject with for an intracellular pathogen infection, by administering an agent that reduces the binding of CD47 on a infected cell to SIRP? on a host phagocytic cell, in an effective dose for increasing the phagocytosis of infected cells.

Abstract: Methods are provided for treating a subject with for an intracellular pathogen infection, by administering an agent that reduces the binding of CD47 on a infected cell to SIRP? on a host phagocytic cell, in an effective dose for increasing the phagocytosis of infected cells.

Abstract: The present invention relates to a method for measuring de novo T-cell production in humans, and more particularly to the assessement recent thymic emigrant (RTE) diversity in a T-cell sub-population of a patient by the detection of T-cell receptor &bgr; chain DNA deletion circles (TCR&bgr;DC) generated during TCR gene rearrangement of thymocytes in the thymus. The method comprises isolating a T-cell sub-population from a patient, extracting genomic DNA from the T-cell sub-population, amplifying the genomic DNA with a primer specific for a T-cell receptor &bgr; chain DNA rearrangement deletion circle (TCR&bgr;DC) family and detecting the TCR&bgr;DC, the TRC&bgr;DC being indicative of the presence of a RTE. The method assesses the quantitative and qualitative (diversity) intrathymic T-cell production by quantitating the relative frequency and diversity of RTEs within various sub-populations of circulating human T-cells.

Abstract: The invention provides methods for screening agents for potential anti-viral effects by assessing the ability of the agents to suppress viral replication and/or pathology in thymic cells grown in thymic organ culture in vitro. Also provided are methods to study viral pathology and infectivity.

Abstract: A method for initiating metastasis of human tumor cells under experimental conditions is provided. Immunocompromised non-human mammals having a viable, xenogeneic organ or tissue are used as a host for human tumor cells. The cells are introduced into the chimeric animal after the solid tissue is implanted and are then able to grow and metastasize as they would in situ. Therapeutic regimens may be evaluated in this system to determine efficacy against metastatic processes.

Abstract: Xenogeneic tissue is introduced into an immunocompromised host for interacting with agents and using such interaction for evaluating efficacy of drugs and vaccines, producing xenogeneic monoclonal antibodies, evaluating the effect of the various agents on specific tissues and the like. Particularly, drugs can be evaluated for their efficacy against a wide variety of pathogens which infect xenogeneic tissue, agents can be evaluated for their effect on the xenogeneic immune system and monoclonal antibodies to a predetermined epitope may be produced.

Abstract: Chimeric immunocompromised hosts are provided, comprising human bone marrow of at least 4 weeks from the time of implantation. The bone marrow is found to assume the normal population of bone marrow except for erythrocytes. The bone marrow may be used to study the effect of various agents on the proliferation and differentiation of hematopoietic cells.

Abstract: A human hematopoietic system is provided in an immunocompromised mammalian host, where the hematopoietic system is functional for extended periods of time. Particularly, human fetal liver tissue and human fetal thymus is introduced into an appropriate site of a young immunocompromised mouse at a site supplied with a vascular system, whereby the fetal tissue results in novel formation of functional human bone marrow tissue.

Abstract: A method is provided for screening compounds for the ability to supress thymocyte depletion in thymuses of HIV-infected individuals, particularly enhancing the CD4.sup.+ -expressing population as compared to an untreated individual. Particularly, drugs are provided which allow for this result, cyclosporine A being exemplary.

Abstract: The invention provides methods for screening agents for potential anti-viral effects by assessing the ability of the agents to suppress viral replication and/or pathology in thymic cells grown in thymic organ culture in vitro. Also provided are methods to study viral pathology and infectivity.

Abstract: A human hematopoietic system is provided in an immunocompromised mammalian host, where the hematopoietic system is functional for extended periods of time. Particularly, human fetal liver tissue and human fetal thymus is introduced into an appropriate site of a young immunocompromised mouse at a site supplied with a vascular system, whereby the fetal tissue results in novel formation of functional human bone marrow tissue.

Abstract: Human lymphoid tissue is introduced into an immunocompromised host to provide opportunities to investigate the effect of stimuli on the human immune system and obtain information and products from the stimulus. Particularly, methodology is provided for the production of human monoclonal antibodies by introducing lymphoid tissue into an immunocompromised host, stimulating the B-lymphocytes with an appropriate immunogen, harvesting the tissue and immortalizing and/or cloning the B-lymphocytes under conditions to obtain a stable supply of monoclonal antibodies.