Browsing by Author "Mhandire, Kudakwashe"

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    Genetic variation in toll like receptors 2, 7, 9 and interleukin-6 is associated with cytomegalovirus infection in late pregnancy
    (2020-05-25) Mhandire, Doreen Z; Mhandire, Kudakwashe; Magadze, Mulalo; Wonkam, Ambroise; Kengne, Andre P; Dandara, Collet
    Background Maternal cytomegalovirus (CMV) infection and/or reactivation in pregnancy is associated with a myriad of adverse infant outcomes. However, the role of host genetic polymorphisms in modulating maternal CMV status is inconclusive. This study investigated the possible association of single nucleotide polymorphisms in toll-like receptor (TLR) and cytokine genes with maternal plasma CMV DNA status in black Zimbabweans. Methods In a cross-sectional study, 110 women in late gestation who included 36 CMV infected cases and 74 CMV uninfected, age and HIV status matched controls were enrolled. Twenty single nucleotide polymorphisms in 10 genes which code for proteins involved in immunity against CMV were genotyped using Iplex GOLD SNP genotyping protocol on the Agena MassARRAY® system. Statistical analyses were performed using Stata SE and the ‘Genetics’ and ‘SNPassoc’ packages of the statistical package R. Results The TLR7 rs179008A > T (p < 0.001) polymorphism was associated while the TLR9 rs352139T > C (p = 0.049) polymorphism was on the borderline for association with CMV positive (CMV+) status. In contrast, the interleukin (IL)-6 rs10499563T > C (p < 0.001) and TLR2 rs1816702C > T (p = 0.001) polymorphisms were associated with CMV negative (CMV-) status. Furthermore, allele frequencies of SNPs in TLR2, TLR4, TLR9, TLR7, IL-6, IL-10, IL-28B, IL-1A and interferon AR1 (IFNAR1) genes are being reported here for the first time in a Zimbabwean population. The allele frequencies in the Zimbabwean population are generally comparable to other African populations but different when compared to European and Asian populations. Conclusions Toll-like receptor and interleukin genetic polymorphisms influence CMV status in late gestation among black Zimbabweans. This is attributable to possible modulation of immune responses to CMV reactivation in a population previously exposed to CMV infection.
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    Virus restriction gene variants and their possible role in neurocognitive function in children born to HIV-infected mothers
    (2012) Mhandire, Kudakwashe; Dandara, Collet
    Host genetic variation is an important determinant of HIV infection, disease progression and HIV-associated neurocognitive deficits. However, there is no sufficient knowledge on the role of genetic variants especially among African populations. This study is focused on investigating variation in HIV/AIDS restriction genes; CCR2, CX3CR1, SDF1, RANTES, APOBEC3G and MBL2 and their possible role in HIV infection and neurocognitive function among children born to HIV infected mothers, recruited in Harare, Zimbabwe. A total of 116 children comprising of 73 perinatally exposed to HIV (34 who were born infected and 39 who were uninfected) and 43 unexposed controls were recruited in 2011(at ages 7-9 years) from a cohort of mother-baby pairs that has been followed up since 2002. The demographic characteristics of the recruited children were captured from their medical records. A McCarthy Scale of Children‟s Abilities (MSCA) was administered to determine each child‟s neurocognitive status. Genotyping for allelic variants was done using PCR-RFLP, SNaPshot® and Sanger DNA sequencing. Statistical analysis was carried out to determine association between genotypes, HIV status and neurocognitive function. The observation of different genetic variants or combinations of genotypes between the HIV-exposed and infected group and that of the HIV-exposed but uninfected group may be a pointer to critical pathways in differential HIV susceptibility. Exposure and infection with HIV is controlled by a multitude of genes/processes, thus, SNPs are unlikely to show statistically significant effects individually and may be more useful in a multifactorial model, as observed from comparisons of genotype combinations and haplotypes. The role of host genetic variation on neurocognitive function remains disputed but our observations suggest innate immune factors such as MBL2 may have a pronounced effect. Therefore, it may be possible to genotype for a suite of genes and use them as markers of either HIV susceptibility or neuro-developmental patterns.