Publications by authors named "Nicholas Lejarcegui"
The role of Myeloid-Derived Suppressor Cells (MDSC) in infant immune ontogeny is unknown. Here, we evaluated MDSC frequency and relationship with infant vaccine responses throughout the first year of life in a prospective cohort study. Ninety-one South African infant-mother pairs were enrolled at delivery, and blood samples were collected at 0, 6, 10, and 14 weeks, 6 months, 9 months, and 1 year.
View Article and Find Full Text PDFOver 4 million infants die each year from infections, many of which are vaccine-preventable. Young infants respond relatively poorly to many infections and vaccines, but the basis of reduced immunity in infants is ill defined. We sought to investigate whether myeloid-derived suppressor cells (MDSC) represent one potential impediment to protective immunity in early life, which may help inform strategies for effective vaccination prior to pathogen exposure.
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- The study aimed to identify immune factors in neonates that influence the transmission of HIV-1 from mother to child, comparing infants who got infected to those who did not.
- Researchers analyzed cord blood samples for natural killer (NK) and T-cell populations using advanced techniques and found that infected infants had a unique NK cell profile and less activated immune cells.
- Results suggested that the differences in immune cell types and activation levels in the cord blood could affect the risk of HIV-1 transmission, highlighting the role of both innate and adaptive immunity in this process.
Background: Neonatal Natural Killer (NK) cells show functional impairment and expansion of a CD56 negative population of uncertain significance.
Methods: NK cells were isolated from cord blood and from adult donors. NK subpopulations were identified as positive or negative for the expression of CD56 and characterized for expression of granzyme B and surface markers by multi-parameter flow cytometry.
Article Synopsis
- Specific HLA allele groups, particularly HLA-B*27 and HLA-B*57, are linked to better control over HIV-1, as they help maintain the function of CD8(+) T cells during chronic infection.
- Unlike T cells with nonprotective HLA alleles that are suppressed by regulatory T cells (T(reg)), those with protective HLA alleles are resistant to this suppression and can even kill T(reg) cells directly.
- The study highlights how the interaction between specific HLA alleles and T cell responses contributes to slower HIV-1 disease progression, revealing new insights into immune evasion mechanisms.
The liver stages of Plasmodium, the causative agent of malaria, are the least explored forms in the parasite's life cycle despite their recognition as key vaccine and drug targets. In vivo experimental access to liver stages of human malaria parasites is practically prohibited and therefore rodent model malaria parasites have been used for in vivo studies. However, even in rodent models progress in the analysis of liver stages has been limited, mainly due to their low abundance and associated difficulties in visualisation and isolation.
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