Impact of TLR7 and TLR9 polymorphisms on susceptibility to placental infections and pregnancy complications

Unraveling Immunological Dynamics: HPV Infection in Women-Insights from Pregnancy

During pregnancy, hormonal and immune adaptations are vital for supporting the genetically distinct fetus during elevated infection risks. The global prevalence of HPV necessitates its consideration during pregnancy. Despite a seemingly mild immune response, historical gestational viral infections underscore its significance. Acknowledging the established HPV infection risks during pregnancy, our review explores the unfolding immunological changes in pregnant women with HPV. Our analysis aims to uncover strategies for safely modulating the immune system, mitigating adverse pregnancy consequences, and enhancing maternal and child health. This comprehensive narrative review delves into the existing knowledge and studies on this topic.

HLA-G alleles and their impacts on placental HSV-1 infection in women from southern Brazil

The Human Leukocyte Antigen G (HLA-G) is an immunoregulatory molecule with a critical role in pregnancy success. HLA-G alleles are associated with differential susceptibility to multiple conditions, including gestational problems, infectious diseases, and viral persistence. Of note, both herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) can impair HLA-G expression, interfering with HLA-G-associated immunoregulation. On the other hand, the impacts of HLA-G alleles on susceptibility to Herpesviridae infection is a neglected issue. Therefore, this study evaluated HLA-G allele frequencies and their associations with placental Herpesviridae infection in women from southern Brazil. Placenta samples were collected soon after delivery, and detection of viral DNA of HSV-1, HSV-2 and human cytomegalovirus (HCMV) was performed by polymerase chain reaction (PCR). A fragment of HLA-G (exons 2-4) was amplified by PCR, sequenced, and analyzed to allele determination. One hundred and seventy women had their alleles determined. Overall, 25 HLA-G alleles were found, distributed into 56 different genotypes. The most frequent alleles were G* 01:01:01 and G* 01:01:02, found in 37.9 % and 16.5 % of samples, respectively. Among the 170 women, 89 (52.4 %) tested positive for Herpesviridae DNA in the placenta, 55 (32.3 %) tested negative, 3 (1.8 %) were negative for HSV-1 and HSV-2 (with absent HCMV data), and 23 (13.5 %) were undetermined. The G* 01:01:01 allele was significantly associated with an increased risk of placental HSV-1 infection (p = 0.0151; OR=1.837; IC=1.108-3.045). This study describes new information concerning placental HLA-G alleles in women from southern Brazil and helps explain how genetic background can modify susceptibility to placental infections.

Association between genetic variants in TREM1, CXCL10, IL4, CXCL8 and TLR7 genes with the occurrence of congenital Zika syndrome and severe microcephaly

Congenital Zika syndrome (CZS) is a cluster of malformations induced by Zika virus (ZIKV) infection and the underline mechanisms involved in its occurrence are yet not fully understood. Along with epidemiological and environmental factors, the genetic host factors are suggested as important to the CZS occurrence and development, however, few studies have evaluated this. This study enrolled a total of 245 individuals in a case-control association study compound a cohort of high specific interest constituted by 75 mothers who had delivered CZS infants, their 76 infants, and 47 mothers that had delivered healthy infants, and their 47 infants. Sixteen single-nucleotide polymorphisms on TREM1, CXCL10, IL4, CXCL8, TLR3, TLR7, IFNR1, CXCR1, IL10, CCR2 and CCR5 genes were genotyped to investigate their association as risk factors to CZS. The results show an association between C allele at TREM1 rs2234246 and C allele at IL4 rs224325 in mothers infected with ZIKV during pregnancy, with the increased susceptibility to CZS occurrence in their infants and the SNP CXCL8 rs4073 and the G allele at CXCL10 rs4508917 with presence of CZS microcephaly in the infants. Furthermore, the T allele at CXCL8 rs4073 and TRL7 rs179008 SNPs were associated with the severity of microcephaly in children with CZS. These results suggest that these polymorphisms in genes of innate immune responses addressed here are associated to increased risk of occurrence and severity of CZS in pregnant mothers infected with ZIKV and their CZS infants.

Synthesizing the connections between environmental disturbances and zoonotic spillover

Zoonotic spillover is a phenomenon characterized by the transfer of pathogens between different animal species. Most human emerging infectious diseases originate from non-human animals, and human-related environmental disturbances are the driving forces of the emergence of new human pathogens. Synthesizing the sequence of basic events involved in the emergence of new human pathogens is important for guiding the understanding, identification, and description of key aspects of human activities that can be changed to prevent new outbreaks, epidemics, and pandemics. This review synthesizes the connections between environmental disturbances and increased risk of spillover events based on the One Health perspective. Anthropogenic disturbances in the environment (e.g., deforestation, habitat fragmentation, biodiversity loss, wildlife exploitation) lead to changes in ecological niches, reduction of the dilution effect, increased contact between humans and other animals, changes in the incidence and load of pathogens in animal populations, and alterations in the abiotic factors of landscapes. These phenomena can increase the risk of spillover events and, potentially, facilitate new infectious disease outbreaks. Using Brazil as a study model, this review brings a discussion concerning anthropogenic activities in the Amazon region and their potential impacts on spillover risk and spread of emerging diseases in this region.

TLR9 2848 G/A Gene Polymorphism in HCV+, HIV+, and HCV+/HIV+ Individuals

Background: Host genetic factors have a major impact on susceptibility to infections. Toll-like receptors (TLRs) and their polymorphisms affect infectious diseases once they are directly involved in immune responses. The 2848 G/A variant (rs352140) of the TLR9 gene is associated with increased TLR9 expression. However, the impact of rs352140 on HIV+, HCV+, and HCV+/HIV+ individuals is still debated. Materials and Methods: This study investigated the 2848 G/A polymorphism in hepatitis C virus (HCV) infection, human immunodeficiency virus (HIV) infection, and HCV/HIV coinfection in a large sample of Brazilians (n = 1182). Groups were compared without considering stratification by ethnicity and subsequently stratifying individuals into groups of whites and nonwhites. Results: Considering nonwhite individuals, a significant difference between the HIV+/HCV+ group and controls was observed (p = 0.023; GG genotype as a protective factor). In addition, significant allele differences were observed between the HCV+ group and controls (p = 0.042), between the HIV+/HCV+ group and controls (p = 0.011), and between the HIV+/HCV+ group and HIV+ individuals (p = 0.047). However, all significant results are lost if adjustment by multiple comparisons is applied (p > 0.05). Conclusions: Although our initial results indicate a potential influence of rs352140 on altered host susceptibility to viral infections, no statistical influence of polymorphism on protection from/susceptibility to infections was observed in Brazilians if adjustment by multiple comparisons is considered.

Human cytomegalovirus infection and its association with gestational diabetes mellitus during pregnancy

BACKGROUND

Infection is an important risk factor for gestational diabetes mellitus (GDM), while infection of human cytomegalovirus (HCMV) with GDM remains unclear and rarely reported. This study aimed to investigate the association of HCMV infection and serum inflammatory factor levels in pregnancy with GDM.

METHODS

This prospective study included pregnant women who attended at Affiliated Hospital of Qingdao Hospital and Zibo Maternal and Child Health Hospital between December 2018 and August 2020. HCMV specific IgM and serum levels of inflammatory factors, including TNF-α, IL-6, and IL-1β, were analyzed.

RESULTS

A total of 5,316 pregnant women were included (415 with GDM (107 with HCMV+GDM+ and 308 with HCMV-GDM+) and 4901 GDM-free (759 with HCMV+GDM- and 4142 with HCMV-GDM-)). The prevalence of GDM was 7.81%. The rate of activation of HCMV was 16.29%. Specifically, 107 and 759 women in the GDM and control group exhibited HCMV infection, with positive rates of25.78% and 15.48%, respectively (P < 0.01). TNF-α, IL-6, and IL-1β at 24-28 weeks of gestation were significantly higher in women with GDM and HCMV infection than inthe other groups (all P < 0.01). Multivariable analysis showed that HCMV positive (OR = 1.851; 95% CI [1.425-2.403]; P < 0.001), IL-6 (OR = 1.010; 95% CI [1.002-1.018]; P = 0.013), and IL-1β (OR = 1.410; 95% CI [1.348-1.474]; P < 0.001) were all significantly correlated with GDM.

CONCLUSION

This study suggests HCMV infection during pregnancy is an independent risk factor of GDM and could significantly increase its incidence. Further studies are needed to elucidate possible mechanisms underlying associations between HCMV infection and GDM.