Abstract: The invention provides vaccination protocols for administering immunogens to a primate host in order to promote the formation of neutralizing antibodies (NAbs) against primate immunodeficiency viruses. In some embodiments, the vaccination protocols comprise the step of administering to a primate host a first immunogen comprising at least one primate immunodeficiency virus Envelope (env) sequence having a first set of consensus glycosylation sequences, followed by a second immunogen comprising at least one primate immunodeficiency virus env sequence having a second set of consensus glycosylation sequences, wherein the differences between the first set of consensus glycosylation sequences and the second set of consensus glycosylation sequences comprise differences in consensus glycosylation sequences observed in HIV isolates obtained at different time points of a natural infection.

Abstract: In one aspect, the invention provides an HIV envelope heterotrimer comprising at least two different Env glycoprotein monomers. In some heterotrimers, at least two Env glycoprotein monomers are from different HIV isolates, for example, different HIV-1 isolates. Heterotrimers may contain Env glycoprotein monomers from HIV isolates belonging to the same clade or to different clades or both. At least one of the Env glycoprotein monomers in a heterotrimer of the invention may be modified in a way that alters its amino acid composition. In another aspect, the invention provides methods for inducing an immune response in a vertebrate host against HIV or an HIV-infected cell, comprising administering to a vertebrate host a prophylactically or therapeutically effective amount of a composition comprising an HIV envelope heterotrimer.

Abstract: Method for inoculating a vertebrate host against malaria, by administering to the host a live Plasmodium organism that is genetically engineered to disrupt a liver-stage-specific gene function.

Abstract: Method for inoculating a vertebrate host against malaria, by administering to the host a live Plasmodium organism that is genetically engineered to disrupt a liver-stage-specific gene function.

Abstract: Method for inoculating a vertebrate host against malaria, by administering to the host a live Plasmodium organism that is genetically engineered to disrupt a liver-stage-specific gene function.

Abstract: Method for inoculating a vertebrate host against malaria, by administering to the host a live Plasmodium organism that is genetically engineered to disrupt a gene whose expression is up-regulated in liver stage parasites and whose function is not required for entry into hose hepatocytes.

Abstract: Method for inoculating a vertebrate host against malaria, by administering to the host a live Plasmodium organism that is genetically engineered to disrupt a liver-stage-specific gene function.

Abstract: The invention relates to stem cell compositions comprising anti-TGF-&bgr; treated stem cells which are viable for at least 14 days in culture without replication or differentiation and methods for rapid and long term in vitro hematopoiesis and in vivo hematopoietic reconstitution using such anti-TGF-&bgr; treated stem cells.