Redirecting T Cells to Glypican-3 with 4-1BB Zeta Chimeric Antigen Receptors Results in Th1 Polarization and Potent Antitumor Activity.

T cells engineered to express CD19-specific chimeric antigen receptors (CARs) have shown breakthrough clinical successes in patients with B-cell lymphoid malignancies. However, similar therapeutic efficacy of CAR T cells in solid tumors is yet to be achieved. In this study we systematically evaluated a series of CAR constructs targeting glypican-3 (GPC3), which is selectively expressed on several solid tumors.

CD62L+ NKT cells have prolonged persistence and antitumor activity in vivo.

Vα24-invariant natural killer T cells (NKTs) localize to tumors and have inherent antitumor properties, making them attractive chimeric antigen receptor (CAR) carriers for redirected cancer immunotherapy. However, clinical application of CAR-NKTs has been impeded, as mechanisms responsible for NKT expansion and the in vivo persistence of these cells are unknown. Here, we demonstrated that antigen-induced expansion of primary NKTs in vitro associates with the accumulation of a CD62L+ subset and exhaustion of CD62L- cells.

Invariant NKT cells with chimeric antigen receptor provide a novel platform for safe and effective cancer immunotherapy.

Advances in the design of chimeric antigen receptors (CARs) have improved the antitumor efficacy of redirected T cells. However, functional heterogeneity of CAR T cells limits their therapeutic potential and is associated with toxicity. We proposed that CAR expression in Vα24-invariant natural killer T (NKT) cells can build on the natural antitumor properties of these cells while their restriction by monomorphic CD1d limits toxicity.

IL-15 protects NKT cells from inhibition by tumor-associated macrophages and enhances antimetastatic activity.

Vα24-invariant NKT cells inhibit tumor growth by targeting tumor-associated macrophages (TAMs). Tumor progression therefore requires that TAMs evade NKT cell activity through yet-unknown mechanisms. Here we report that a subset of cells in neuroblastoma (NB) cell lines and primary tumors expresses membrane-bound TNF-α (mbTNF-α).

Overexpression of CXC chemokine ligand 14 exacerbates collagen-induced arthritis.

CXCL14 is a relatively new chemokine with unidentified receptor and undefined function. Recently, we found that CXCL14 is upregulated in arthritic joints in a mouse model of autoimmune arthritis, collagen-induced arthritis. To examine the role of CXCL14 in the development and pathogenesis of autoimmune arthritis, we have generated transgenic (Tg) mice that overexpress CXCL14 under control of phosphoglycerate kinase promoter.

Inhibition of clonal expansion by Foxp3 expression as a mechanism of controlled T-cell responses and autoimmune disease.

The essential role of the transcription factor Foxp3 in the development and function of Treg has been well documented. The role of Foxp3 in non-Treg, however, is not fully understood. Emerging evidence indicates that Foxp3 expression is not confined to CD4+CD25+ Treg.

Identification of IL-17-producing FOXP3+ regulatory T cells in humans.

IL-17-producing CD4(+) T helper (Th17) cells have recently been defined as a unique subset of proinflammatory helper cells whose development depends on signaling initiated by IL-6 and TGF-beta, autocrine activity of IL-21, activation of STAT3, and induction of the orphan nuclear receptor RORgammat. The maintenance, expansion, and further differentiation of the committed Th17 cells depend on IL-1beta and IL-23. IL-17 was originally found produced by circulating human CD45RO(+) memory T cells.

Exacerbation of autoimmune arthritis by copolymer-I through promoting type 1 immune response and autoantibody production.

Copolymer-I (COP-I) is an unique immune regulatory polymer that has been shown to suppress experimental autoimmune encephalomyelitis (EAE) and is a treatment option for multiple sclerosis (MS). To investigate whether its immune suppressive effects can be extended to other autoimmune diseases, we treated mice with COP-I during the induction of collagen-induced arthritis (CIA). Our results show that COP-I treatment exacerbated CIA, leading to faster onset, more severe and longer-lasting disease.

Overexpression of Bcl(XL) in B cells promotes Th1 response and exacerbates collagen-induced arthritis.

B cells play a pathogenic or regulatory role in many autoimmune diseases through production of autoantibodies, cytokine production, and Ag presentation. However, the mechanisms that regulate these B cell functions under different autoimmune settings remain unclear. In the current study, we found that when B cells overexpress an antiapoptotic gene, Bcl(XL), they significantly increased production of IFN-gamma and enhanced Th1 response.

Rectification of age-associated deficiency in cytotoxic T cell response to influenza A virus by immunization with immune complexes.

Decline in cellular immunity in aging compromises protection against infectious diseases and leads to the increased susceptibility of the elderly to infection. In particular, Ag-specific cytotoxic T lymphocyte (CTL) response against virus is markedly reduced in an aged immune system. It is of great importance to explore novel strategy in eliciting effective antiviral CTL activity in the elderly.

Correction of age-associated deficiency in germinal center response by immunization with immune complexes.

In aging, both primary and secondary antibody responses are impaired. One of the most notable changes in age-associated immune deficiency is the diminished germinal center (GC) reaction. This impaired GC response reduces antibody affinity maturation, decreases memory B cell development, and prevents the establishment of long-term antibody-forming cells in the bone marrow.

Germinal center helper T cells are dual functional regulatory cells with suppressive activity to conventional CD4+ T cells.

Germinal center (GC) reaction is a T cell-dependent process in which activated B cells mature to produce high-affinity Abs and differentiate into memory B cells. The GC microenvironment is almost exclusively reserved for the optimal Ag-specific B cell clonal expansion, selection, and maturation, but lack significant conventional CD4(+) T cell responses. The mechanisms that ensure such a focused B cell response in the GC are not known.

Human germinal center T cells are unique Th cells with high propensity for apoptosis induction.

Collaborative interactions between T(h) cells and B cells are necessary for the production of antibody responses to most protein antigens and for the generation of memory B cells in germinal centers (GCs). Although it is well established that T(h) cells are pivotal for the GC reaction, the mechanisms that control the homeostasis of T(h) cells during the GC response remain largely unknown. Here we show that, unlike other effector T cells, a significant number of CD4(+)CD45RO(+)CD57(+) T cells, which are the major T(h) cells residing in the GCs, are undergoing apoptosis in vivo.

Blockade of lymphotoxin pathway exacerbates autoimmune arthritis by enhancing the Th1 response.

Objective: To study the role of the lymphotoxin (LT) signaling pathway in the development and pathogenesis of collagen-induced arthritis (CIA), and to understand the mechanisms by which blockade of the LT pathway influences the arthritogenic response to type II collagen (CII).

Methods: LTalpha-deficient and wild-type C57BL/6 mice were immunized with CII. Male DBA/1 mice were immunized with CII and treated with LTbeta receptor immunoglobulin fusion protein (LTbetaR-Ig) or control Ig.

CXCL13 neutralization reduces the severity of collagen-induced arthritis.

Objective: To investigate the role of CXCL13 in the development and pathogenesis of collagen-induced arthritis (CIA), and to determine the mechanisms involved in the modulation of arthritogenic response by CXCL13 neutralization.

Methods: Mice were immunized with type II collagen (CII) and treated with anti-CXCL13 or control antibodies during boosting. Mice were monitored for the development and severity of arthritis.

Rectification of age-related impairment in Ig gene hypermutation during a memory response.

The deficiency in generating high-affinity antibodies due to impaired somatic hypermutation of Ig genes in the germinal center (GC) is considered the major mechanism responsible for the compromised humoral responses in aging. Since the intrinsic capability of aged B lymphocytes to respond to initial antigenic stimuli is largely intact and the expression of activation-induced cytidine deaminase, a key component required for Ig somatic hypermutation, is comparable between B cells from aged and young mice, it is possible to restore the age-related deficiency in the humoral response by circumventing the requirement for signals from other immune components. Here, we show that GC B cells from aged mice during a memory response carried mutated Ig genes with mutational frequencies comparable to that of GC B cells from young mice.

Cutting edge: gamma delta T cells provide help to B cells with altered clonotypes and are capable of inducing Ig gene hypermutation.

It has not been resolved whether gammadelta T cells can collaborate with germinal center B cells and support Ig hypermutation during an Ab response to a truly defined T-dependent Ag. In this study, we show that in the absence of alphabeta T cells, immunization with the well-defined T-dependent Ag, (4-hydroxy-3-nitrophenyl) acetyl (NP) conjugate, was able to induce Ig hypermutation. However, the clonotypes of B cells responding to NP were dramatically altered in TCR beta(-/-) mice.

Enhanced differentiation of splenic plasma cells but diminished long-lived high-affinity bone marrow plasma cells in aged mice.

In the present work, we have dissected the mechanisms responsible for the impaired humoral responses in aging. We found that there was a substantially higher level of Ab-forming cells in the spleens of aged mice than that of young controls. However, the number of high-affinity, class-switched Ab-forming cells was severely decreased in the spleen of aged mice.