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Background: Coinfection with HIV and Plasmodium parasites is fairly common, but the sequence of infection with these two pathogens and their impact on disease progression are poorly understood. Methods: A Chinese rhesus macaque HIV and Plasmodium coinfection model was established to compare the impact of pre-existing and subsequent malaria on the progression of SIV infection. Results: We found that a pre-existing malaria caused animals to produce a greater number of CD4+CCR5+ T cells for SIV replication, resulting in higher viral loads. Conversely, subsequent malaria induced a substantially larger proportion of CD4+CD28highCD95high central memory T cells and a stronger SIV-specific T cell response, maintained the repertoire diversity of SIV-specific T cell receptors, and generated new SIV-specific T cell clonotypes to trace SIV antigenic variation, resulting in improved survival of SIV-infected animals. Conclusion: The complex outcomes of this study may have important implications for research on human HIV and malaria coinfection. The infection order of the two pathogens (HIV and malaria parasites) should be emphasized. 41xUPjAsGDR_p5XJNXr9fi Video abstract [ABSTRACT FROM AUTHOR]

Previous research has proven that disruption of either the CCR5 or the CXCR4 gene confers resistance to R5-tropic or X4-tropic human immunodeficiency virus type 1 (HIV-1) infection, respectively. However, the urgent need to ablate both of the co-receptors in individual post-thymic CD4+ T cells for dual protection remains. This study ablated the CCR5 and CXCR4 genes in human CD4+ cell lines and primary CD4+ T cells simultaneously using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9, a well-developed, highly efficient genetic engineering tool. The efficiency of gene modification is as high as 55% for CCR5 and 36% for CXCR4 in CD4+ cell lines through infection of a single lentiviral vector (LV-X4R5), which were markedly protected from both HIV-1NL4-3 (X4-using strain) and HIV-1YU-2 (R5-using strain) infection. Importantly, approximately 9% of the modified GHOST (3) CXCR4+CCR5+ cells harbor four bi-allelic gene disruptions in both the CXCR4 and CCR5 loci. Moreover, co-delivery of two single-guide RNAs loaded with Cas9: ribonucleoprotein (sgX4&R5 Cas9RNP) disrupted >12% of CCR5 and 10% of CXCR4 in primary human CD4+ T cells, which were rendered resistant to HIV-1NL4-3 and HIV-1YU-2 in vitro. Further, the modified cells do not show discernible mutagenesis in top-ranked off-target genes by the Surveyor assay and Sanger sequencing analysis. The results demonstrate the safety and efficacy of CRISPR/Cas9 in multiplex gene modification on peripherally circulating CD4+ T cells, which may promote a functional cure for HIV-1 infection. [ABSTRACT FROM AUTHOR]

We previously reported that Plasmodium infection promotes antitumor immunity in a murine Lewis lung cancer. In this study, we investigated the effects of Plasmodium infection on the tumor inhibition and antitumor CD8+ T cell responses in a murine triple negative breast cancer (TNBCA) model. The results showed that Plasmodium infection significantly inhibited tumor growth, and increased the survival rate of the tumor-bearing mice. Both effector and memory CD8+ T cells were increased in peripheral blood and tumor-draining lymph node (DLN) in the infected mice. The co-stimulatory (CD40L, GITR and OX-40) and co-inhibitory (PD-1, CTLA-4, TIM-3, LAG3) immune checkpoints were up-regulated on CD8+ T cells in infected mice. Importantly, Py induced remarkable effects on the infiltration of CD8+ T cells in the tumor and granzym B+ CD8+ T cells in tumor-bearing mice while not in tumor-free mice. In summary, the results suggested that the effects of Plasmodium infection on murine 4T1 breast cancer might be related to the induction of CD8+ T cell-mediated antitumor immune responses. This finding may provide a novel strategy for the treatment of triple negative breast cancer. Graphic summary for Plasmodium infection inhibiting triple negative 4T1 breast cancer potentially through induction of CD8+ T cell-mediated antitumor responses in mice [Display omitted] • Plasmodium infection inhibited tumor growth and increased the survival rate of triple negative 4T1 breast cancer-bearing mice. • Plasmodium infection increased the proportion of CD8+ effector and memory T cells in the infected mice. • Plasmodium infection induced remarkable effects on granzym B+ CD8+ T cell in tumor-bearing mice while not in tumor-free mice. • Plasmodium infection promoted the infiltration of CD8+ T cells in the tumor tissues of the triple negative 4T1 breast cancer-bearing mice. [ABSTRACT FROM AUTHOR]