CXCR3 Expression Pattern on CD4+ T Cells and IP-10 Levels with Regard to the HIV-1 Reservoir in the Gut-Associated Lymphatic Tissue

Abstract

(1) Background: The gut-associated lymphatic tissue (GALT) represents the largest lymphoid organ, and is considered to be the largest HIV reservoir. The exact size of the GALT reservoir remains unclear. Several markers, such as the chemokine receptor CXCR3 and its pro-inflammatory ligand IP-10, have been proposed to define the size of HIV reservoirs in the peripheral blood (PB). However, little is known about the role of CXCR3 and IP-10 within the GALT. (2) Methods: We compared the CXCR3 expression, IP-10 levels, and cell-associated HIV DNA of distinct memory CD4+T cell subsets from the terminal ileum (TI), PB and rectum (RE) of 18 HIV+ patients with antiretroviral therapy (ART), 6 HIV+ treatment-naive patients and 16 healthy controls. (3) Results: While the relative distributions of CD4+ T-cell subsets were similar in PB, TI and RE, HIV DNA and CXCR3 expression were markedly increased and IP-10 levels were decreased in TI when compared to PB. No significant correlation was found between the CXCR3 expression and memory CD4+ T-cell subsets, IP-10 levels and the HIV DNA amounts measured in PB , TI or RE. (4) Conclusions: During a chronic HIV-1 infection, neither CXCR3 nor IP-10 are indicative of the size of the viral reservoir in the GALT (TI and RE).

Lymphoid tissues contribute to plasma viral clonotypes early after antiretroviral therapy interruption in SIV-infected rhesus macaques

“…Despite previous observations regarding the capacity of the small intestine to contain large SIV pools ( 23 , 24 ), no viral barcodes detected in ATI-2 plasma were found in the samples of small intestine here analyzed, and only one animal from group 2 showed detectable intact proviral DNA there. Similarly, only one animal had a viral barcode clonotype detected in the colon sample that was also found in plasma during ATI-2.…”

Lymphoid tissues contribute to viral clonotypes present in plasma at early post-ATI in SIV-infected rhesus macaques

“…Despite previous observations regarding the capacity of the small intestine to contain large SIV pools (19,20), no viral barcodes detected in ATI-2 plasma were found in the samples of small intestine herein analyzed, and only one animal from group 2 showed detectable intact proviral DNA there. Similarly, only one animal had a viral barcode clonotype detected in the colon sample that was also found in plasma during ATI-2.…”