SAMHD1 expression is associated with low immune activation but not correlated with HIV‑1 DNA levels in CD4+ T cells of patients with HIV‑1

Sterile alpha motif and histidine-aspartic acid domain-containing protein 1 expression and its relationship with T cell activation in human immunodeficiency virus/acquired immune deficiency syndrome patients with lung-spleen deficiency syndrome pattern

OBJECTIVE

To investigate the relationship between antiviral restriction factor Sterile Alpha Motif and Histidine-Aspartic acid domain-containing protein 1 (SAMHD1) expression and T cell activation, furthermore, identifying objective indexes of lung-spleen deficiency symptom pattern.

METHODS

We assessed the profile of T lymphocyte subsets, characteristics of SAMHD1 and human leukocyte antigen DR (HLA-DR) expression in lung-spleen deficiency patients. At the same time, people living with human immunodeficiency virus / acquired immune deficiency syndrome (HIV/AIDS) (PLWHA) without obvious clinical symptoms and healthy donors in this area were used as controls.

RESULTS

Immunohematologic indexes lower CD4 count, lower CD4/CD8 ratio and higher SAMHD1 level were found in lung-spleen deficiency patients. Furthermore, we demonstrated a positive relationship between SAMHD1 and HLA-DR level as well as with interferon factor in lung-spleen deficiency syndrome and patients without obvious clinical signs and symptoms groups.

CONCLUSIONS

These data indicated the positive relationship between SAMHD1 and T cell activation which further elucidated the role of SAMHD1 in cellular immune response. Furthermore, combination of T lymphocyte subsets counts and SAMHD1 level may be used as clinical and biological reference basis for the differentiation and diagnosis of HIV / AIDS traditional Chinese medicine syndromes.

Immunological effector mechanisms in HIV-1 elite controllers

PURPOSE OF REVIEW

HIV-1 elite controllers encompass small populations of people infected with HIV-1 who can spontaneously control plasma viral loads below the limit of detection, in the absence of antiretroviral treatment. Antiviral immune responses are likely to contribute to such an impressive HIV-1 disease outcome. In this review, we discuss recent novel findings regarding antiviral innate and adaptive immune responses in elite controllers.

RECENT FINDINGS

Elite controllers maintain a pool of infected cells in which intact HIV-1 proviruses are more frequently integrated into noncoding regions of the host genome, likely conferring a state of deep latency. This atypical viral reservoir configuration is best explained by potent antiviral immune responses that can successfully eliminate virally infected cells in which proviruses are integrated into permissive chromatin. However, identifying the specific type and nature of this immune selection pressure represents a formidable challenge. Recent studies continue to support the role of HIV-1-specific CD8+ T cells as the main driver of elite immune control of HIV-1, however, increasing evidence suggests that their role is complemented by a fine-tuned interplay with innate immune cell subsets. Therefore, the combination of different immune effector mechanisms may shape antiviral immunity in elite controllers.

SUMMARY

Understanding the complex immune mechanisms responsible for natural, drug-free HIV-1 control represents a premier avenue to find and develop interventions for a cure of HIV-1 infection. Future single-cell assays designed to uncover the full genetic, epigenetic, transcriptional and functional complexity of antiviral immune responses in elite controllers may allow us to define correlates of antiviral immune protection in greater detail.