Disease relevance of APOBEC3B

• We report here that two additional APOBEC3 family members, APOBEC3B and APOBEC3C, have potent antiviral activity against simian immuno-deficiency virus (SIV), but not HIV-1 [1].
• APOBEC3B and APOBEC3C are potent inhibitors of simian immunodeficiency virus replication [1].
• Three of these, rat APOBEC1, mouse APOBEC3, and human APOBEC3B, are able to inhibit HIV infectivity even in the presence of Vif [2].
• Although human T-cell leukemia virus type 1 (HTLV-1) replicates in the same cell type as HIV-1, it was shown here that HTLV-1 is relatively resistant to the antiviral effects mediated by human APOBEC3B, -3C, -3F and -3G [3].
• Identification of APOBEC3B as a potential target for the graft-versus-lymphoma effect by SEREX in a patient with mantle cell lymphoma [4].

High impact information on APOBEC3B

• Here, we demonstrate that APOBEC3A and APOBEC3B, two members of the APOBEC3 family of human innate antiretroviral resistance factors, can enter the nucleus, where LINE-1 and Alu reverse transcription occurs, and specifically inhibit both LINE-1 and Alu retrotransposition [5].
• G --> A hypermutated HBV genomes were recovered from transfection experiments involving APOBEC3B, -3C, -3F, and -3G indicating that all four enzymes were able to extensively deaminate cytidine residues in minus-strand DNA [6].
• We show that normal human liver expresses the mRNAs of APOBEC3B (A3B), APOBEC3C (A3C), A3F, and A3G [7].
• In addition, lower levels of retrotransposed L1 DNA accumulated in the presence of APOBEC3B and APOBEC3F [8].
• We now show that the first two complement control protein (CCP) modules of the C4BP alpha-chain, plus the four residues connecting them, are necessary and sufficient for binding a bacterial virulence factor, the Streptococcus pyogenes M4 (Arp4) protein [9].

Biological context of APOBEC3B

• Second, cDNA strand-specific C --> T hypermutations were not detected among L1 elements that had replicated in the presence of APOBEC3B or APOBEC3F [8].
• Functional central polypurine tract provides downstream protection of the human immunodeficiency virus type 1 genome from editing by APOBEC3G and APOBEC3B [10].
• We have examined to what extent human immunodeficiency virus type 1 plus-strand initiation at the central polypurine tract (cPPT) could protect the viral genome from DNA editing by APOBEC3G and APOBEC3B [10].
• Antibody responses to APOBEC3B were correlated with clinical response [4].
• Among these are a highly conserved Arp1 protein (likely part of a conserved dynactin complex), and Arp4 and Arp6 homologues (subunits of the chromatin-remodeling machinery) [11].

Anatomical context of APOBEC3B

• We demonstrate that APOBEC3C and APOBEC3B were endogenously expressed in HeLa cells [12].
• These studies therefore raise the possibility that activation of the endogenous APOBEC3B gene in primary human lymphoid cells could form a novel and effective strategy for inhibition of HIV-1 replication in vivo [13].
• We screened an MCL cDNA expression library with sera at GVL response after allogeneic haematopoietic stem cell transplantation and isolated five genes including APOBEC3B [4].

Other interactions of APOBEC3B

• Three of them, APOBEC3G, APOBEC3F, and APOBEC3B, block replication of human immunodeficiency virus type 1 (HIV-1) and many other retroviruses [14].
• APOBEC3A and APOBEC3B are potent inhibitors of LTR-retrotransposon function in human cells [15].
• Microarray analyses were performed and several genes related to HIV biology, including APOBEC3B, DEFA1, and S100 calcium-binding protein genes, were found to be regulated by prostratin [16].

Analytical, diagnostic and therapeutic context of APOBEC3B

• Two case reports describing hypernephromas in kidneys with ARCD 3 years after successful renal transplantation are presented [17].

References