IL-7/IL-7R gene variants impact circulating IL-7/IL-7R homeostasis and ART-associated immune recovery status

A relationship between polymorphisms in genes encoding interleukin 7 (IL-7) and its cellular receptor (IL-7R) and antiretroviral therapy (ART)-associated immune recovery in HIV subjects has been previously reported. However, details of this relationship remain unclear, and the association of these polymorphisms with circulating IL-7/IL-7R levels is scarce. Here, we explored whether IL-7/IL-7R axis was associated with quantitative CD4+ T-cell recovery in HIV-infected subjects. IL-7/IL-7R polymorphisms were assessed by genotyping, and multiple inheritance models were used to estimate both, their association with low pre-ART CD4+ T-cell counts and incomplete immune recovery status after 48 weeks of suppressive ART. Integrated data from genetic variants association and soluble plasma IL-7/IL-7R quantification suggest that IL-7/IL-7R genotype expression could alter the homeostatic balance between soluble and membrane-bound receptors. The haplotype analyses indicates that allele combinations impacts pre-ART circulating CD4+ T-cell counts, immune recovery status and the absolute increment of CD4+ T-cell counts. The knowledge about how IL-7/IL-7R axis is related to quantitative CD4+ T-cell recovery and immune recovery status after initiating ART could be useful regarding T-cell reservoirs investigations in HIV subjects.
This work was supported by the Fondo de Investigacion Sanitaria [PI10/02635, PI13/0796, PI14/1693, PI16/00503, PI16/00684, PI19/01337]-ISCIII-FEDER; Programa de Suport als Grups de Recerca AGAUR (2014SGR250, 2017SGR948); Gilead Fellowship Program GLD14/293 and GLD17/00299; The SPANISH AIDS Research Network [RD12/0017/0005, RD16/0025/0002, RD16/0025/0006, RD16/0025/0019, RD16/0025/0020]-ISCIII-FEDER (Spain) and Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (Proyecto de Investigación de Excelencia; CTS2593). FV is supported by grants from the Programa de Intensificación de Investigadores (INT15/226)-ISCIII. YMP and ERM are supported by the Servicio Andaluz de Salud through Programa Nicolás Monardes (C-0013/17 and C-0032/17, respectively). E.R-M was also supported by Programa Miguel Servet ISCIII, FEDER, CPII014/00025. AR is supported by a grant from the Acció Instrumental d’incorporació de científics i tecnòlegs (PERIS SLT002/16/00101), Departament de Salut, Generalitat de Catalunya and Agencia Estatal de Investigación (Acciones de carácter internacional “Europa Investigación”; EUIN2017-89297), Ministry of Economy and Competitiveness. We are also grateful to GESIDA for ‘‘Premio para Jóvenes Investigadores 2019’’ to AR.