Altered immunological reactivity in HIV-1-exposed uninfected neonates (original) (raw)
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Clinical Infectious Diseases, 2002
encounter among uninfected infants of HIV-infected mothers. Peripheral blood cells of more than one-third of these exposed-uninfected infants proliferate and produce IL-2 after stimulation with HIV, and HIV-specific CD4 + T helper cell responses can be quantified in nearly all when sensitive intracellular cytokine assays are used. HIV-specific CD8 + cytotoxic T lymphocyte responses can be elicited in some, although less frequently. It is difficult to demonstrate that these responses are components of protective immunity and not simply epiphenomena of exposure. However, HIV-specific responses are associated with lack of infection, even with prolonged reexposure through breast-feeding. Elevations in nonspecific markers of immune activation provide further corroboration, as do similar findings in adults, consistent across all known routes of HIV transmission. Many questions remain, but much can be learned from this special population that may be informative for development of effective immunity in response to HIV vaccines.
In-utero infection with HIV-1 associated with suppressed lymphoproliferative responses at birth
Clinical & Experimental Immunology, 2014
In-utero exposure to HIV-1 may affect the immune system of the developing child and may induce HIV-1-specific immune responses, even in the absence of HIV-1 infection. We evaluated lymphoproliferative capacity at birth among 40 HIV-1-uninfected infants born to HIV-1-infected mothers and 10 infants who had acquired HIV-1 in utero. Cord blood mononuclear cells were assayed using [ 3 H]-thymidine incorporation for proliferation in response to HIV-1 p55-gag and the control stimuli phytohaemagglutinin (PHA), Staphylococcus enterotoxin B (SEB) and allogeneic cells. In response to HIV-1 p55-gag, eight (20%) HIV-1-exposed, uninfected (EU) infants had a stimulation index (SI) ≥ 2 and three (30%) in-utero HIV-1 infected infants had SI ≥2. The frequency and magnitude of responses to HIV-1 p55-gag were low overall, and did not differ statistically between groups. However, proliferative responses to control stimuli were significantly higher in EU infants than in infants infected in utero, with a median SI in response to PHA of 123 [interquartile range (IQR) 77-231] versus 18 (IQR 4-86) between EU and infected infants, respectively (P < 0•001). Among infected infants, gestational maturity was associated with the strength of HIV-1 p55-gag response (P < 0•001); neither maternal nor infant HIV-1 viral load was associated. In summary, EU and HIV-1-infected infants mounted HIV-1-specific lymphoproliferative responses at similar rates (20-30%), and although global immune function was preserved among EU infants, neonatal immune responses were significantly compromised by HIV-1 infection. Such early lymphoproliferative compromise may, in part, explain rapid progression to AIDS and death among HIV-1-infected infants.
BMC Infectious Diseases, 2011
Background Children born to HIV+ mothers are exposed intra-utero to several drugs and cytokines that can modify the developing immune system, and influence the newborn's immune response to infections and vaccines. We analyzed the relation between the distribution of cord blood lymphocyte subsets and cytokine profile in term newborns of HIV+ mothers using HAART during pregnancy and compared them to normal newborns. Methods In a prospective, controlled study, 36 mother-child pairs from HIV+ mothers and 15 HIV-uninfected mothers were studied. Hematological features and cytokine profiles of mothers at 35 weeks of pregnancy were examined. Maternal and cord lymphocyte subsets as well as B-cell maturation in cord blood were analyzed by flow cytometry. The non-stimulated, as well as BCG- and PHA-stimulated production of IL2, IL4, IL7, IL10, IL12, IFN-γ and TNF-alpha in mononuclear cell cultures from mothers and infants were quantified using ELISA. Results After one year follow-up none of the exposed infants became seropositive for HIV. An increase in B lymphocytes, especially the CD19/CD5+ ones, was observed in cord blood of HIV-exposed newborns. Children of HIV+ hard drug using mothers had also an increase of immature B-cells. Cord blood mononuclear cells of HIV-exposed newborns produced less IL-4 and IL-7 and more IL-10 and IFN-γ in culture than those of uninfected mothers. Cytokine values in supernatants were similar in infants and their mothers except for IFN-γ and TNF-alpha that were higher in HIV+ mothers, especially in drug abusing ones. Cord blood CD19/CD5+ lymphocytes showed a positive correlation with cord IL-7 and IL-10. A higher maternal age and smoking was associated with a decrease of cord blood CD4+ cells. Conclusions in uninfected infants born to HIV+ women, several immunological abnormalities were found, related to the residual maternal immune changes induced by the HIV infection and those associated with antiretroviral treatment. Maternal smoking was associated to changes in cord CD3/CD4 lymphocytes and maternal hard drug abuse was associated with more pronounced changes in the cord B cell line.
PLOS One, 2006
Background. In utero transmission of HIV-1 occurs on average in only 3%-15% of HIV-1-exposed neonates born to mothers not on antiretroviral drug therapy. Thus, despite potential exposure, the majority of infants remain uninfected. Weak HIV-1specific T-cell responses have been detected in children exposed to HIV-1, and potentially contribute to protection against infection. We, and others, have recently shown that the removal of CD4 + CD25 + T-regulatory (Treg) cells can reveal strong HIV-1 specific T-cell responses in some HIV-1 infected adults. Here, we hypothesized that Treg cells could suppress HIV-1-specific immune responses in young children. Methodology/Principal Findings. We studied two cohorts of children. The first group included HIV-1-exposed-uninfected (EU) as well as unexposed (UNEX) neonates. The second group comprised HIV-1-infected and HIV-1-EU children. We quantified the frequency of Treg cells, T-cell activation, and cell-mediated immune responses. We detected high levels of CD4 + CD25 + CD127 2 Treg cells and low levels of CD4 + and CD8 + T cell activation in the cord blood of the EU neonates. We observed HIV-1-specific T cell immune responses in all of the children exposed to the virus. These T-cell responses were not seen in the cord blood of control HIV-1 unexposed neonates. Moreover, the depletion of CD4 + CD25 + Treg cells from the cord blood of EU newborns strikingly augmented both CD4 + and CD8 + HIV-1-specific immune responses. Conclusions/Significance. This study provides new evidence that EU infants can mount strong HIV-1-specific T cell responses, and that in utero CD4 + CD25 + T-regulatory cells may be contributing to the lack of vertical transmission by reducing T cell activation.
Brazilian Journal of Medical and Biological Research, 2008
The immune consequences of in utero HIV exposure to uninfected children whose mothers were submitted to highly active antiretroviral therapy (HAART) during gestation are not well defined. We evaluated 45 HIV-exposed uninfected (ENI) neonates and 45 healthy unexposed control (CT) neonates. All HIV-infected mothers received HAART during pregnancy, and the viral load at delivery was <50 copies/mL for 56.8%. Twenty-three ENI neonates were further evaluated after 12 months and compared to 23 unexposed healthy age-matched infants. Immunophenotyping was performed by flow cytometry in cord and peripheral blood. Cord blood lymphocyte numbers did not differ between groups. However, ENI neonates had a lower percentage of naive T cells than CT neonates (CD4+, 76.6 vs 83.1%, P < 0.001; CD8+, 70.9 vs 79.6%, P = 0.003) and higher percentages of central memory T cells than CT neonates (CD4+, 13.9 vs 8.7%, P < 0.001; CD8+, 8.6 vs 4.8%, P = 0.001). CD38 mean fluorescence intensity of T cells was higher in ENI neonates (CD4+, 62.2 vs 52.1, P = 0.007; CD8+, 47.7 vs 35.3, P < 0.001). At 12 months, ENI infants still had higher mean fluorescence intensity of CD38 on T cells (CD4+, 34.2 vs 23.3, P < 0.001; CD8+, 26.8 vs 19.4, P = 0.035). Despite effective maternal virologic control at delivery, HIV-exposed uninfected children were born with lower levels of naive T cells. Immune activation was present at birth and remained until at least 12 months of age, suggesting that in utero exposure to HIV causes subtle immune abnormalities.
Clinical and Vaccine Immunology, 2005
This study of a subset of women and infants participating in National Institutes of Health Pediatric AIDS Clinical Trials Group protocol 185 evaluated lymphocyte phenotypic markers of immune activation and differentiation to determine their association with the likelihood of human immunodeficiency virus (HIV) transmission from the women to their infants and the potential for early identification and/or prognosis of infection in the infants. Lymphocytes from 215 human immunodeficiency virus type 1 (HIV)-infected women and 192 of their infants were analyzed by flow cytometry with an extended three-color panel of monoclonal antibodies. Women who did not transmit to their infants tended to have higher CD4+ T cells. Most notably, levels of total CD8+ T cells and CD8+ CD38+ cells made significant independent contributions to predicting the risk of mother-to-child transmission. Adjusting for HIV-1 RNA level at entry, a one percentage-point increase in these marker combinations was associated with a nine percent increase in the likelihood of maternal transmission. Total as well as naive CD4+ T cells were significantly higher in uninfected than infected infants. Total CD8+ cells, as well as CD8+ cells positive for HLA-DR+, CD45 RA+ HLA-DR+, and CD28+ HLA-DR+ were elevated in infected infants. Detailed immunophenotyping may be helpful in predicting which pregnant HIV-infected women are at increased risk of transmitting HIV to their infants. Increasing differences in lymphocyte subsets between infected and uninfected infants became apparent as early as six weeks of age. Detailed immunophenotyping may be useful in supporting the diagnosis of HIV infection in infants with perinatal HIV exposure.
Blood, 2000
Cell-mediated immunity and T-lymphocyte maturation are impaired in HIVinfected children. These abnormalities would be detected in HIV-uninfected offspring of HIV women (seroreverters [SR]) if HIV or its soluble proteins could cross the placental barrier. Immunophenotypic analyses were performed in 20 healthy HIV-uninfected newborns of HIV-infected mothers (SR), and in 14 healthy newborns of HIV-negative women (UC). The same analyses were performed in 3 groups of older children: SR (n ؍ 41); UC (n ؍ 15); and HIV-infected children (n ؍ 25). Anti-gen-specific cells were evaluated with ELISpot and fluorimetric analyses; IL-7 serum concentration was measured by enzyme-linked immunosorbent assay (ELISA). Results showed that in SR newborns: (1) the CD4/CD8 ratio was reduced, (2) CD4 ؉ and CD8 ؉ naive T-cell percentages were decreased, (3) percentage of activated CD8 ؉ T cells was increased, and (4) percentages of CD3 ؉ / 4 ؊ /8 ؊ (DN) and DN/25 ؊ /44 ؉ were augmented. These abnormalities were partially retained in older SR children. CD4 ؉ and CD8 ؉ HIV-specific cells were detected in a portion of newborn SRs but not in older SRs. Serum IL-7 was augmented both in newborn and older SRs. Cell-mediated immunity and T-cell maturation are altered even in HIV-uninfected newborns of HIV-infected mothers; these abnormalities persist over time. The biologic significance of these observations and potential subsequent clinical events should be investigated in larger cohorts of seroreverters. (Blood. 2000;96:3866-3871)
The Journal of Infectious Diseases, 2000
238 infants were measured at birth and at 1, 2, 4, and 6 months after birth, to estimate their association with perinatal transmission and infant disease progression. Maternal anti-p24 ( ) and anti-gp120 ( ) antibodies were inversely associated with vertical trans-P p .01 P p .04 mission rates, independent of maternal percentage of CD4 cells, hard drug use, duration of ruptured membranes, serum albumin levels, serum vitamin A levels, and quantitative HIV-1 peripheral mononuclear blood cell culture, but not with maternal plasma immune complex dissociated p24 or HIV-1 RNA copy number, both of which were highly correlated with antibodies. From ages 1-2 months, anti-gp120, -gp41, -p31, and -p66 decayed to a greater extent in infected than in uninfected infants. Infected infants produced anti-p24 antibody by age 2 months, anti-p17 by 4 months, and anti-p41 and anti-gp120 by 6 months. As early as birth, infants with rapid disease progression had lower levels of anti-p24 than did infants whose disease did not rapidly progress, but not independently of HIV-1 RNA levels.
Altered innate immune development in HIV-exposed uninfected infants
JAIDS Journal of Acquired Immune Deficiency Syndromes, 2014
Background: Early in life, HIV-exposed uninfected (HEU) infants are at an increased risk of morbidity and mortality from infectious disease compared with HIV-unexposed (UE) infants. To improve our understanding of the mechanisms underlying their increased risk, we contrasted innate immune development between HEU and UE infants in a developing world setting, where early life infectious disease risk is exceptionally high.