Prescott S, Mutka T, Baumgartel K, Yoo JY, Morgan H, Postolache TT, Seyfang A, Gostner JM, Fuchs D, Kim K, Groer ME. Tryptophan metabolism and immune alterations in pregnant Hispanic women with chronic Toxoplasma gondii infection.
Am J Reprod Immunol 2023;
90:e13768. [PMID:
37641377 PMCID:
PMC10538252 DOI:
10.1111/aji.13768]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 07/18/2023] [Accepted: 08/09/2023] [Indexed: 08/31/2023] Open
Abstract
PROBLEM
Pregnancy markedly modifies women's metabolism and immune functions. We hypothesized that pregnancy might alter the immune and metabolic responses to chronic Toxoplasma gondii infection in pregnancy.
METHOD OF STUDY
A population of 690 pregnant Hispanic women were screened for antibodies to T. gondii and 158 women were positive (23% positivity) with 83% showing high avidity indices. These seropositive women were followed through their pregnancies with four data collection time points and a postpartum collection at two clinics in Tampa, Florida. A T. gondii seronegative group (N = 128) was randomly selected to serve as a control group and measured along pregnancy in the same way. Serum levels of tryptophan, kynurenine, and their ratio, phenylalanine, tyrosine and their ratio, neopterin, and nitrite were measured through pregnancy and the postpartum. A plasma cytokine panel (IFN-γ, TNFα, IL-2, IL-10, IL-12, IL-6, IL-17) was analyzed in parallel.
RESULTS
The major findings suggest that indoleamine 2,3-dioxygenase (IDO-1) was less activated in T. gondii seropositive pregnant Hispanic women with chronic infection. Evidence for IDO-1 suppression was that tryptophan catabolism was less pronounced and there were lower levels of multiple inflammatory cytokines including IFN-γ, which is the major inducer of IDO-1, and higher nitrite concentration, a surrogate marker for nitric oxide, an inhibitor of IDO.
CONCLUSIONS
Latent T. gondii infection was associated with higher plasma tryptophan levels, and lower inflammatory cytokines across pregnancy, suggesting suppression of the IDO-1 enzyme, and possible T cell exhaustion during pregnancy.
Collapse