Cytomegalovirus (CMV) is a prevalent β-herpesvirus that persists asymptomatically in immunocompetent hosts. In people with HIV-1 (PWH), CMV is associated with persistence of the HIV-1 reservoir and particular inflammatory related co-morbidities. The true causative role of CMV in HIV-associated pathologies remains unclear given that nearly all PWH are coinfected with CMV. In this study, we examined acute phase SIV dynamics in cohorts of rhesus macaques that were seropositive or -negative for rhesus CMV (RhCMV). We observed expansion of CCR5+ target CD4+ T cells in gut and lymph nodes (LN) that existed naturally in RhCMV-seropositive animals, the majority of which did not react to RhCMV lysate. These cells expressed high levels of the chemokine receptor CXCR3 and a ligand for this receptor, CXCL9, was systemically elevated in RhCMV-seropositive animals. RhCMV+ RMs also exhibited higher peak SIV viremia. CCR5 target memory CD4 T cells in the gut of RhCMV+ RMs were maintained during acute SIV and this was associated with greater seeding of SIV DNA in the intestine. Overall, our data suggests the ability of RhCMV to regulate chemotactic axes that direct lymphocyte trafficking and promote seeding of SIV in a diverse, polyclonal pool of memory CD4+ T cells.

Pregnant women are at increased risk of adverse outcomes, including preeclampsia and preterm birth, that may result from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Pregnancy imprints specific maternal immune responses that can modulate host susceptibility to microbial infection; therefore, recent studies have focused on the humoral response against SARS-CoV-2 in pregnant women. However, the pregnancy-specific cellular immune responses triggered by SARS-CoV-2 infection are poorly understood. In this study, we undertook an extensive in vitro investigation to determine the cellular immune responses to SARS-CoV-2 particles and proteins/peptides in pregnant women. First, we show that SARS-CoV-2 particles do not alter the pregnancy-specific oxidative burst of neutrophils and monocytes. Yet, SARS-CoV-2 particles/proteins shift monocyte activation from the classical to intermediate states in pregnant, but not in nonpregnant, women. Furthermore, SARS-CoV-2 proteins, but not particles or peptide pools, mildly enhance T cell activation during pregnancy. As expected, B cell phenotypes are heavily modulated by SARS-CoV-2 particles in all women; yet, pregnancy itself further modified such responses in these adaptive immune cells. Lastly, we report that pregnancy itself governs cytokine responses in the maternal circulation, of which IFN-β and IL-8 were diminished upon SARS-CoV-2 challenge. Collectively, these findings highlight the differential in vitro responses to SARS-CoV-2 in pregnant and nonpregnant women and shed light on the immune mechanisms implicated in coronavirus disease 2019 during pregnancy.
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