630. Identification of a Depressed Mucosal Immune Environment in HIV Infection
Session: Poster Abstract Session: Pathogenesis and Immune Response
Thursday, October 4, 2018
Room: S Poster Hall
Background:Among patients with human immunodeficiency virus
(HIV), pulmonary complications are a common cause of morbidity and mortality.
Emerging evidence suggests that respiratory viruses contributes to this disease
burden. Although HIV is known to alter other mucosal surfaces including the GI
tract and vagina, its effect on the upper respiratory mucosa, the primary
target of respiratory viruses, has not been well-described. We sought to characterize
the effect of HIV on the upper respiratory mucosal immune environment.
Methods:Ten HIV-infected patients and 10 sex-matched
uninfected controls were enrolled. Subjects were ages 18-49, nonsmokers, and
otherwise healthy. HIV-infected subjects had complete viral load suppression
for at least 6 months prior to participation. Subjects provided serum samples
and underwent nasal mucosal sampling procedures -- epithelial lining fluid
(ELF) collection, nasal lavage (NLF) and nasal biopsy. Serum, ELF, and NLF were
analyzed using ELISAs targeted at pro-inflammatory cytokines. NLF was analyzed
by flow cytometry for nasal-specific immune cells.
Results:T-cells in NLF, including both CD8 and CD4 populations,
were significantly decreased in HIV-infected compared to uninfected subjects.
We also found decreased numbers of neutrophils. Additionally, we identified
diminished levels of IL-16 in ELF, a T-cell chemoattractant in HIV-infected
subjects; however, all other cytokines and chemokines were similar between the
two groups. These findings were in contrast to an earlier study we had done in
6 HIV-infected men with variable levels of HIV control and age-matched control
subjects which also demonstrated decreased levels of other pro-inflammatory cytokines,
including IL-Iβ, IL-8, and IL-5 in those with HIV.
Conclusion:The mechanism underlying the morbidity and mortality
of respiratory viruses in HIV-infected patients is unclear. However, we
identified that HIV infection does result in relative upper respiratory immune
suppression, including in both CD4 and CD8 T-cell populations, despite
otherwise excellent systemic control of HIV. We hypothesize that this
suppression persists in viral infection leading to an impaired immune response
and prolonged respiratory virus replication, contributing to the observed
burden of disease in this population.
Subhashini Sellers, MD, Division of Pulmonary and Critical Care, University of North Carolina, Chapel Hill, NC, Kelly Chason, B.S., Division of Pulmonary Diseases and Critical Care Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC and William Fischer II, MD, Division of Pulmonary and Critical Care Medicine, University of North Carolina School of Medicine, Chapel Hill, NC