RESUMEN
We have designed and validated a novel generic platform for production of tetravalent IgG1-like chimeric bispecific Abs. The VH-CH1-hinge domains of mAb2 are fused through a peptidic linker to the N terminus of mAb1 H chain, and paired mutations at the CH1-CL interface mAb1 are introduced that force the correct pairing of the two different free L chains. Two different sets of these CH1-CL interface mutations, called CR3 and MUT4, were designed and tested, and prototypic bispecific Abs directed against CD5 and HLA-DR were produced (CD5xDR). Two different hinge sequences between mAb1 and mAb2 were also tested in the CD5xDR-CR3 or -MUT4 background, leading to bispecific Ab (BsAbs) with a more rigid or flexible structure. All four Abs produced bound with good specificity and affinity to CD5 and HLA-DR present either on the same target or on different cells. Indeed, the BsAbs were able to efficiently redirect killing of HLA-DR(+) leukemic cells by human CD5(+) cytokine-induced killer T cells. Finally, all BsAbs had a functional Fc, as shown by their capacity to activate human complement and NK cells and to mediate phagocytosis. CD5xDR-CR3 was chosen as the best format because it had overall the highest functional activity and was very stable in vitro in both neutral buffer and in serum. In vivo, CD5xDR-CR3 was shown to have significant therapeutic activity in a xenograft model of human leukemia.
Asunto(s)
Anticuerpos Biespecíficos/biosíntesis , Anticuerpos Biespecíficos/genética , Inmunoglobulina G/biosíntesis , Inmunoglobulina G/genética , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Secuencia de Aminoácidos , Animales , Anticuerpos Biespecíficos/química , Anticuerpos Biespecíficos/inmunología , Anticuerpos Biespecíficos/aislamiento & purificación , Antígenos/inmunología , Baculoviridae/genética , Línea Celular , Diseño de Fármacos , Expresión Génica , Vectores Genéticos/genética , Humanos , Inmunoglobulina G/química , Inmunoglobulina G/inmunología , Inmunoglobulina G/aislamiento & purificación , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Unión Proteica/inmunología , Conformación Proteica , Estabilidad Proteica , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/aislamiento & purificación , Alineación de Secuencia , Resonancia por Plasmón de SuperficieAsunto(s)
Anticuerpos/efectos de los fármacos , Antígenos CD20/inmunología , Benzamidas/farmacología , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Pirazinas/farmacología , Benzamidas/uso terapéutico , Humanos , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Pirazinas/uso terapéuticoAsunto(s)
Mutación , Leucemia-Linfoma Linfoblástico de Células Precursoras , Proteína p53 Supresora de Tumor/genética , Adulto , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Tasa de SupervivenciaRESUMEN
Here, we describe the immunoglobulin and T cell receptor (Ig/TCR) molecular rearrangements identified as a leukemic clone hallmark for minimal residual disease assessment in relation to TP53 mutational status in 171 Ph-negative Acute Lymphoblastic Leukemia (ALL) adult patients at diagnosis. The presence of a TP53 alterations, which represents a marker of poor prognosis, was strictly correlated with an immature DH/JH rearrangement of the immunoglobulin receptor (p < 0.0001). Furthermore, TP53-mutated patients were classified as pro-B ALL more frequently than their wild-type counterpart (46% vs. 25%, p = 0.05). Although the reasons for the co-presence of immature Ig rearrangements and TP53 mutation need to be clarified, this can suggest that the alteration in TP53 is acquired at an early stage of B-cell maturation or even at the level of pre-leukemic transformation.