Loss of CD127 & increased immunosenescence of T cell subsets in HIV infected individuals.
OBJECTIVE
HIV infection is characterized by a perturbation in T cell homeostasis, leading to alteration in T cell subsets. In addition to alteration in differentiation, HIV infection also leads to change in T cell survival and regenerative capacity, as suggested by differential expression of CD127 and CD57. We evaluated the expression patterns of CD127 and CD57 on CD4 and CD8 effector, memory and naïve T cell subsets in HIV-infected and uninfected individuals.


METHODS
We characterized T cell subsets based on expression of these markers, and compared their expression pattern in HIV infected subjects and uninfected controls. We further assessed therapy generated changes in these subsets and expression of CD127 and CD57 on them.


RESULTS
There was a generalized decrease in naïve CD4 and CD8 T cells in HIV infected subjects. These changes in T cell subset distribution were related to antigen load. CD127 expression was significantly reduced in T cells from HIV infected subject. In association to this, HIV infected subjects had higher percentage of T cell subsets expressing CD57. Increased CD57 and reduced CD127 expression correlated with plasma viraemia and CD8 T cell activation state. Incomplete restoration of T cell subset proportions was observed, despite suppression of viral replication and increase in CD4 T cell counts. Further, the improvement was more pronounced in CD127 expression.


CONCLUSIONS
HIV infected subjects have reduced T cell regenerative capacity along with increased senescence, highlighting decreased proliferation and effector activities.
Department of Microbiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
Kamalika
K
Mojumdar
Madhu
M
Vajpayee
Neeraj Kumar
NK
Chauhan
Alpana
A
Singh
Ravinder
R
Singh
Sravya
S
Kurapati
D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D016516:CD4-CD8 Ratio; D018959:CD57 Antigens / Q000378:metabolism*; D002454:Cell Differentiation / Q000276:immunology*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D053699:Interleukin-7 Receptor alpha Subunit / Q000172:deficiency / Q000378:metabolism*; D008297:Male; D018709:Statistics, Nonparametric; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D018959:CD57 Antigens; D053699:Interleukin-7 Receptor alpha Subunit