Wuchereria bancrofti infection is linked to systemic activation of CD4 and CD8 T cells.

• Main Authors: Inge Kroidl, Mkunde Chachage, Jonathan Mnkai, Anthony Nsojo, Myrna Berninghoff, Jaco J Verweij, Lucas Maganga, Nyanda E Ntinginya, Leonard Maboko, Petra Clowes, Michael Hoelscher, Elmar Saathoff, Christof Geldmacher
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2019-08-01
• Series: PLoS Neglected Tropical Diseases
• Online Access: https://doi.org/10.1371/journal.pntd.0007623

<h4>Background</h4>Susceptibility to HIV has been linked to systemic CD4+ T cell activation in cohorts of seronegative individuals with high HIV-exposure risk. We recently described an increased risk of HIV transmission in individuals infected with Wuchereria bancrofti, the causative agent for lymphatic filariasis, in a prospective cohort study. However, the reason for this phenomenon needs further investigation.<h4>Methodology/principal findings</h4>Two-hundred and thirty-five HIV negative adults were tested using Trop Bio ELISA for detection of W. bancrofti infection and Kato Katz urine filtration and stool based RT-PCR for detection of soil transmitted helminths and schistosomiasis. FACS analysis of the fresh peripheral whole blood was used to measure T cell activation markers (HLA-DR, CD38), differentiation markers (CD45, CD27), markers for regulatory T cells (FoxP3, CD25) and the HIV entry receptor CCR5. Frequencies of activated HLA-DRpos CD4 T cells were significantly increased in subjects with W. bancrofti infection (n = 33 median: 10.71%) compared to subjects without any helminth infection (n = 42, median 6.97%, p = 0.011) or those with other helminths (Schistosoma haematobium, S. mansoni, Trichuris trichiura, Ascaris lumbricoides, hookworm) (n = 151, median 7.38%, p = 0.009). Similarly, a significant increase in HLA-DRposCD38pos CD4 T cells and effector memory cells CD4 T cells (CD45ROposCD27neg) was observed in filarial infected participants. Multivariable analyses further confirmed a link between W. bancrofti infection and systemic activation of CD4 T cells independent of age, fever, gender or other helminth infections.<h4>Conclusions/significance</h4>W. bancrofti infection is linked to systemic CD4 T cell activation, which may contribute to the increased susceptibility of W. bancrofti infected individuals to HIV infection.