ABSTRACT
Pregnancy confers unique immune responses to infection and vaccination across gestation. To date, there is limited data comparing vaccine versus infection-induced nAb to COVID-19 variants in mothers during pregnancy. We analyzed paired maternal and cord plasma samples from 60 pregnant individuals. Thirty women vaccinated with mRNA vaccines were matched with 30 naturally infected women by gestational age of exposure. Neutralization activity against the five SARS-CoV-2 Spike sequences was measured by a SARS-CoV-2 pseudotyped Spike virion assay. Effective nAbs against SARS-CoV-2 were present in maternal and cord plasma after both infection and vaccination. Compared to wild type or Alpha variant Spike, these nAbs were less effective against the Kappa, Delta, and Mu Spike variants. Vaccination during the third trimester induced higher nAb levels at delivery than infection during the third trimester. In contrast, vaccine-induced nAb levels were lower at the time of delivery compared to infection during the first trimester. The transfer ratio (cord nAb level/maternal nAb level) was greatest in mothers vaccinated in the second trimester. SARS-CoV-2 vaccination or infection in pregnancy elicit effective nAbs with differing neutralization kinetics that is impacted by gestational time of exposure. Vaccine induced neutralizing activity was reduced against the Delta, Mu, and Kappa variants. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=155 HEIGHT=200 SRC="FIGDIR/small/21267557v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@4225dborg.highwire.dtl.DTLVardef@c35b5borg.highwire.dtl.DTLVardef@1a2d180org.highwire.dtl.DTLVardef@6863c2_HPS_FORMAT_FIGEXP M_FIG C_FIG
ABSTRACT
OBJECTIVETo investigate maternal immunoglobulins (IgM, IgG) response to SARS-CoV-2 infection during pregnancy and IgG transplacental transfer, to characterize neonatal antibody response to SARS-CoV-2 infection, and to longitudinally follow actively- and passively-acquired SARS-CoV-2 antibodies in infants. DESIGNA prospective observational study. SETTINGA public healthcare system in Santa Clara County (CA, USA). PARTICIPANTSWomen with SARS-CoV-2 infection during pregnancy and their infants were enrolled between April 15, 2020 and March 31, 2021. OUTCOMESSARS-CoV-2 serology analyses in the cord and maternal blood at delivery and longitudinally in infant blood between birth and 28 weeks of life. RESULTSOf 145 mothers who tested positive for SARS-CoV-2 during pregnancy, 86 had symptomatic infections: 78 with mild-moderate symptoms, and eight with severe-critical symptoms. Of the 147 newborns, two infants showed seroconversion at two weeks of age with high levels of IgM and IgG, including one premature infant with confirmed intrapartum infection. The seropositivity rates of the mothers at delivery was 65% (95% CI 0.56-0.73) and the cord blood was 58% (95% CI 0.49-0.66). IgG levels significantly correlated between the maternal and cord blood (Rs= 0.93, p< 0.0001). IgG transplacental transfer ratio was significantly higher when the first maternal positive PCR was 60-180 days before delivery compared to <60 days (1.2 vs. 0.6, p=<0.0001). Infant IgG negative conversion rate over follow-up periods of 1-4, 5-12, and 13-28 weeks were 8% (4/48), 12% (3/25), and 38% (5/13), respectively. The IgG seropositivity in the infants was positively related to IgG levels in the cord blood and persisted up to six months of age. CONCLUSIONSMaternal SARS-CoV-2 IgG is efficiently transferred across the placenta when infections occur more than two months before delivery. Maternally-derived passive immunity may protect infants up to six months of life. Neonates mount a strong antibody response to perinatal SARS-CoV-2 infection.
ABSTRACT
Growing evidence from animal experiments and human epidemiological studies has revealed the intriguing communications between the gut,microbiota and brain,i.e.,the gut-microbiota-brain axis.The microbiota establishes its symbiotic rapport with the host early in life and participates in multiple developmental and physiological processes,including regulating brain development and influencing behavior and neurological function.Multiple perinatal factors influence neonatal colonization,and gut dysbiosis is a common finding in preterm infants.Perturbations in the delicate synergetic gut-microbiota-brain communication may have serious consequences,leading to abnormal brain development and long-term neurodevelopment disorders.
ABSTRACT
Objective Using the technology of siRNA to inhibit gene expression of T cells'nonreceptor tyrosine protein kinase Lck in asthmatic mice,and to study the effect of siRNA inhibited Lck to the function of T cells in asthmatic mice.Methods The 21 - 23 bp RNA fragments of mouse T cell Lck were made by chemosynthesis.INTERFERinTMsiRNA Transfection Reagent was used as transfection reagent to transfect the siRNA into the spleen T cells of asthmatic mice for 48 hours.Then T cells were mixed with bone marrow dendritic cells (DC) of asthmatic mice for another 48 hours.Cell culture suspension was collected and the level of IL-4,IL-13,IL-2,INF-γ were detected with respondent ELISA kits; Western Blot was used to identify if the expression of Lck was blocked.Results The expression of Lck in T cells almost could not be detected in siRNA interference group.The levels of IL-4 and IL-13 in siRNA interference group( 10.19 ± 1.66,12.34 ±0.79) were lower than no-siRNA interference(28.06 ±2.88,27.87 ± 1.61 )and control group ( 22.07 ± 2.5 1,20.47 ± 2.37 ),and the difference was statistical significant ( P ＜0.01 ).Conclusions Special siRNA could block the expression of special gene,and Lck specific siRNA could block the activation and differentiation of T cells and reduce the secretion of inflammatory cytokines in asthmatic mice.
