Bovine Neonatal Monocytes Display Phenotypic Differences Compared With Adults After Challenge With the Infectious Abortifacient Agent Neospora caninum.

The neonatal period represents a window of susceptibility for ruminants given the abundance of infectious challenges in their environment. Maternal transfer of immunity does not occur in utero but post-parturition, however this does not compensate for potential deficits in the cellular compartment. Here we present a cellular and transcriptomic study to investigate if there is an age-related difference in the monocyte response in cattle during intra-cellular protozoan infection. We utilized Neospora caninum, an obligate intracellular protozoan parasite that causes abortion and negative economic impacts in cattle worldwide, to study these responses. We found neonatal animals had a significant greater percentage of CD14+ monocytes with higher CD80 cell surface expression. Adult monocytes harbored more parasites compared to neonatal monocytes; additionally greater secretion of IL-1ß was observed in neonates. Microarray analysis revealed neonates have 535 genes significantly upregulated compared to adult with 23 upregulated genes. Biological pathways involved in immune response were evaluated and both age groups showed changes in the upregulation of tyrosine phosphorylation of STAT protein and JAK-STAT cascade pathways. However, the extent to which these pathways were upregulated in neonates was much greater. Our findings suggest that neonates are more resistant to cellular invasion with protozoan parasites and that the magnitude of the responses is related to significant changes in the JAK-STAT network.

Pathogens and the placental fortress.

Placental infections are major causes of maternal and fetal disease. This review introduces a new paradigm for placental infections based on current knowledge of placental defenses and how this barrier can be breached. Transmission of pathogens from mother to fetus can occur at two sites of direct contact between maternal cells and specialized fetal cells (trophoblasts) in the human placenta: firstly, maternal immune and endothelial cells juxtaposed to extravillous trophoblasts in the uterine implantation site and secondly, maternal blood surrounding the syncytiotrophoblast (SYN). Recent findings suggest that the primary vulnerability is in the implantation site. We explore evidence that the placental SYN evolved as a defense against pathogens, and that inflammation-mediated spontaneous abortion may benefit mother and pathogen.

Serological diagnosis of Toxoplasma gondii infection in women associated with gyneco-obstetric problems.

The latex agglutination test (Toxoreagent) was used to detect the sero-prevalence of Toxoplasma gondii in 302 Bangladeshi women who were under treatment for various gyneco-obstetric problems at the Mymensingh Medical College during January to June 1991. The over-all sero-prevalence rate was 15.89%, of which 6.25% reacted at 1:32, 33.33% at 1:64, 16.67% at 1:128, 22.92% at 1:256, 6.25% at 1:512 and 14.58% at 1:1024. The positivity rate of 18.60% recorded in women between 31 and 40 years was insignificantly (p > 0.05) higher than that of 15.44% in women between 17 and 30 years of age. Over-all 26.49% of infections resulted in abortion, 6.62 in stillbirths and 30.79% in dystocia, of which 20.0%, 30.0% and 7.53% women had positive titers to T. gondii, respectively, whereas 17.43% women with normal live births had also positive titers to T. gondii. The over-all prevalence rate of abortion in association with T. gondii infection was 5.30% which was higher than the rates of stillbirths (1.99%) and perinatal death (0.66%). It is concluded that toxoplasmosis can cause abortion, stillbirths and perinatal death in Bangladeshi women.