Publications

OBJECTIVE

We undertook a longitudinal study in rural Uganda to understand the association of food insecurity with morbidity and patterns of healthcare utilization among HIV-infected individuals enrolled in an antiretroviral therapy program.

DESIGN

Longitudinal cohort study.

METHODS

Participants were enrolled from the Uganda AIDS Rural Treatment Outcomes cohort, and underwent quarterly structured interviews and blood draws. The primary predictor was food insecurity measured by the validated Household Food Insecurity Access Scale. Primary outcomes included health-related quality of life measured by the validated Medical Outcomes Study-HIV Physical Health Summary (PHS), incident self-reported opportunistic infections, number of hospitalizations, and missed clinic visits. To estimate model parameters, we used the method of generalized estimating equations, adjusting for sociodemographic and clinical variables. Explanatory variables were lagged by 3 months to strengthen causal interpretations.

RESULTS

Beginning in May 2007, 458 persons were followed for a median of 2.07 years, and 40% were severely food insecure at baseline. Severe food insecurity was associated with worse PHS, opportunistic infections, and increased hospitalizations (results were similar in concurrent and lagged models). Mild/moderate food insecurity was associated with missed clinic visits in concurrent models, whereas in lagged models, severe food insecurity was associated with reduced odds of missed clinic visits.

CONCLUSION

Based on the negative impact of food insecurity on morbidity and patterns of healthcare utilization among HIV-infected individuals, policies and programs that address food insecurity should be a critical component of HIV treatment programs worldwide.

Natural membrane-bound HIV-1 envelope proteins (mHIVenv) could be used to produce an effective subunit vaccine against HIV infection, akin to effective vaccination against HBV infection using the hepatitis B surface antigen. The quaternary structure of mHIVenv is postulated to elicit broadly neutralizing antibodies protective against HIV-1 transmission. The founder virus transmitted to infected individuals during acute HIV-1 infection is genetically homogeneous and restricted to CCR5-tropic phenotype. Therefore, isolates of plasma-derived HIV-1 (PHIV) from infected blood donors while negative for antibodies to HIV proteins were selected for expansion in primary lymphocytes as an optimized cell substrate (OCS). Virions in the culture supernatants were purified by removing contaminating microvesicles using immunomagnetic beads coated with anti-CD45. Membrane cholesterol was extracted from purified virions with beta-cyclodextrin to permeabilize them and expel p24, RT and viral RNA, and permit protease-free Benzonase to hydrolyze the residual viral/host DNA/RNA without loss of gp120. The resultant mHIVenv, containing gp120 bound to native gp41 in immunoreactive form, was free from infectivity in vitro in co-cultures with OCS and in vivo after inoculating SCID-hu Thy/Liv mice. These data should help development of mHIVenv as a virally safe immunogen and enable preparation of polyclonal hyper-immune globulins for immunoprophylaxis against HIV-1 infection.

Sema4D, also known as CD100, is a constitutively expressed immune semaphorin on T cells and NK cells. CD100 has important immune regulatory functions that improve antigen-specific priming by antigen-presenting cells, and can also act as a costimulatory molecule on T cells. We investigated the consequence of HIV-1 infection on CD100 expression by T cells, and whether CD100 expression signifies functionally competent effector cells. CD100 expression on T cells from healthy individuals was compared with HIV-1-infected subjects including elite controllers, noncontrollers, and patients receiving antiretroviral therapy. The frequency and fluorescence intensity of CD100 on CD8(+) and CD4(+) T cells were decreased during HIV-1 infection. Furthermore, the absolute number of CD100-expressing CD8(+) T cells was positively associated with the magnitude of HIV-1-specific T-cell responses. CD8(+) T cells lacking CD100 expression were functionally impaired and present in increased numbers in HIV-1-infected individuals. The number of CD100(-)CD8(+) T cells positively correlated with T-cell immunosenescence, immune activation, and viral load. Loss of CD100 expression appears to result from direct antigen stimulation, as in vitro cytokine exposure and viral replication did not significantly impact CD100 expression. These data suggest that loss of CD100 expression probably plays an important role in dysfunctional immunity in HIV-1 infection.