Allospecific CD8 T suppressor cells induced by multiple MLC stimulation or priming in the presence of ILT3.Fc have similar gene expression profiles

Progress in the research of immunotherapy‑related hyperprogression (Review)

Immunotherapy has become an effective method for the treatment of a variety of malignant tumors. However, with the development of immunotherapy, the phenomenon of hyperprogression in patients with cancer has gradually attracted attention. Hyperprogression refers to a condition in which the progression of a disease during treatment of a patient with cancer is suddenly accelerated. To date, no reliable marker has been found to predict accelerated tumor growth during immune checkpoint inhibitor (ICI) treatment. The aim the present study was to summarize the definition of hyperprogression and the difference between hyperprogression and pseudocytosis, and investigate the potential mechanisms of hyperprogression including clinical characteristics, potential molecular markers and the immune microenvironment. The effect of macrophage-related different types and factors on tumors in the immune microenvironment was analyzed, and the findings may be used to determine the future directions of research in hyperprogression.

Imbalance between CD8+CD28+ and CD8+CD28- T-cell subsets and its clinical significance in patients with systemic lupus erythematosus

OBJECTIVE

The aim of this study was to evaluate the changes in CD8⁺CD28^-/CD8⁺CD28⁺ T-cell subset balance and in the CD8⁺CD28^- Treg cell number and function in patients with systemic lupus erythematosus (SLE).

METHODS

Cell isolation and flow cytometry analysis were employed to investigate the T-cell subsets.

RESULTS

It was found that in high-activity SLE patients, the CD8⁺CD28⁺ T-cell subset was reduced, which was inversely correlated with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and that the CD8⁺CD28^-/CD8⁺CD28⁺ ratio was elevated, which was positively correlated with SLEDAI and with renal damage and inversely correlated with serum complement level, whereas the CD8⁺CD28^- T-cell subset was increased only in inactive patients. It was also found that apoptosis of CD8⁺ T cells increased, and Fas, Fas ligand (FasL) and interleukin (IL)-6 expression were high, whereas cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) expression was low by the CD8⁺CD28⁺ T cell subset in active SLE patients; apoptosis was positively correlated with SLEDAI and with the expression of Fas and FasL by the CD8⁺CD28⁺ T-cell subset in active SLE patients. IL-6 and CTLA-4 expression were found to be low by the CD8⁺CD28^- T cell subset in active SLE patients.

CONCLUSION

These data suggest that high expression of Fas, FasL and IL-6 and low expression of CTLA-4 by the CD8⁺CD28⁺ T-cell subset promotes the activation-induced cell death of the CD8⁺CD28⁺ T-cell subset, resulting in an imbalance of CD8⁺CD28^-/CD8⁺CD28⁺ T cells in active SLE patients, which represents an important feature in the immunological pathogenesis of SLE. The CD8⁺CD28^- T-cell subset may play some role in inactive SLE.

Advances on CD8+ Treg Cells and Their Potential in Transplantation

Although cluster of differentiation (CD)8 regulatory T (Treg) cells have been in the last 20 years more studied since evidences of their role in tolerance as been demonstrated in transplantation, autoimmune diseases and cancer, their characteristics are still controversial. In this review, we will focus on recent advances on CD8 Treg cells and description of a role for CD8 Treg cells in tolerance in both solid organ transplantation and graft-versus-host disease and their potential for clinical trials.

Human CD8+CD28- T Suppressor Cells Expanded by IL-15 In Vitro Suppress in an Allospecific and Programmed Cell Death Protein 1-Dependent Manner

CD8⁺CD28⁻ T suppressor cells (Ts) have been recently documented to play an important role in alloimmunity. Therefore, understanding and optimizing the conditions under which these cells are generated and/or expanded would greatly facilitate further research and potential clinical use. In this study, we describe rapid expansion of human allospecific CD8⁺CD28⁻ Ts cells through coculture of CD8⁺ T cells with human leukocyte antigen-mismatched donor antigen-presenting cells plus IL-15 in a relative short period of time in vitro. Interestingly, IL-15 promotes the expansion of CD8⁺CD28⁻ Ts cells through several parallel mechanisms. The expanded CD8⁺CD28⁻ Ts cells upregulate expression of CD132, CD25, and programmed cell death protein 1 (PD-1), but downregulate expression of CD122, GZM-B, and perforin, while exhibiting no cytotoxicity. Most importantly, the expanded CD8⁺CD28⁻ Ts cells vigorously inhibit CD4⁺ T cells proliferation in a contact-dependent and donor-specific manner both in vitro and in vivo. Interestingly, the co-inhibitory molecules PD-1 and programmed death-ligand 1 play an obligatory role in the mechanisms of CD8⁺CD28⁻ Ts cells suppression. Taken together, our study report novel methodology for IL-15-induced expansion of human CD8⁺CD28⁻ Ts cells and possible mechanisms. These findings may facilitate understanding of transplant rejection and promote clinical application of CD8⁺CD28⁻ Ts cell-based strategies for inducing and monitoring transplant tolerance in the future.

CD28- and CD28lowCD8+ Regulatory T Cells: Of Mice and Men

Since the rebirth of regulatory (formerly known as suppressor) T cells in the early 1990s, research in the field of immune-regulation by various T cell populations has quickly gained momentum. While T cells expressing the transcription factor Foxp3 are currently in the spotlight, several other T cell populations endowed with potent immunomodulatory capacities have been identified in both the CD8⁺ and CD4⁺ compartment. The fundamental difference between CD4⁺ and CD8⁺ T cells in terms of antigen recognition suggests non-redundant, and perhaps complementary, functions of regulatory CD4⁺ and CD8⁺ T cells in immunoregulation. This emphasizes the importance and necessity of continuous research on both subpopulations of regulatory T cells (Tregs) so as to decipher their complex physiological relevance and possible synergy. Two distinct CD8-expressing Treg populations can be distinguished based on expression of the co-stimulatory receptor CD28. Here, we review the literature on these (at least in part) thymus-derived CD28^low and peripherally induced CD28^-CD8⁺ Tregs.

Molecular and Cellular Characterization of Human CD8 T Suppressor Cells

Bidirectional interactions between dendritic cells and Ag-experienced T cells initiate either a tolerogenic or immunogenic pathway. The outcome of these interactions is of crucial importance in malignancy, transplantation, and autoimmune diseases. Blockade of costimulation results in the induction of T helper cell anergy and subsequent differentiation of antigen-specific CD8⁺ T suppressor/regulatory cells (Ts). Ts, primed in the presence of inhibitory signals, exert their inhibitory function in an antigen-specific manner, a feature with tremendous clinical potential. In transplantation or autoimmunity, antigen-specific Ts can enforce tolerance to auto- or allo-antigens, while otherwise leaving the immune response to pathogens uninhibited. Alternatively, blockade of inhibitory receptors results in the generation of cytolytic CD8⁺ T cells, which is vital toward defense against tumors and viral diseases. Because CD8⁺ T cells are MHC Class I restricted, they are able to recognize HLA-bound antigenic peptides presented not only by APC but also on parenchymal cells, thus eliciting or suppressing auto- or allo-immune reactions.

Enhancing adoptive T cell immunotherapy with microRNA therapeutics

Adoptive T cell-based immunotherapies can mediate complete and durable regressions in patients with advanced cancer, but current response rates remain inadequate. Maneuvers to improve the fitness and antitumor efficacy of transferred T cells have been under extensive exploration in the field. Small non-coding microRNAs have emerged as critical modulators of immune system homeostasis and T cell immunity. Here, we summarize recent advances in our understanding of the role of microRNAs in regulating T cell activation, differentiation, and function. We also discuss how microRNA therapeutics could be employed to fine-tune T cell receptor signaling and enhance T cell persistence and effector functions, paving the way for the next generation of adoptive immunotherapies.

microRNAs function in CD8+T cell biology

During an immune response, CD8(+)T cells can differentiate into multiple types of effector and memory cells that are important components of immune surveillance. However, their dysregulation has been implicated in infection with viruses or intracellular bacteria and tumorigenesis. miRNAs have been identified as crucial regulators of gene expression, and they perform this function by repressing specific target genes at the post-transcriptional level. Most miRNAs expressed in a given cell type serve the function to impede broadly cell-type-inappropriate gene expression and potently deepen a pre-existing differentiation program. It is increasingly recognized that miRNAs directly modulate the concentration of many regulatory proteins that are required for the development of immune cells in the thymus and their responses in the periphery. This review outlines our current understanding of the function of miRNAs in CD8(+)T cell biology as it impacts expression of protein-coding genes in the context of proper development, infection, as well as oncogenesis. In addition, we conclude with a perspective on future challenges and the clinical relevance of miRNA biology.