Novel Brain-Penetrant, Small-Molecule Tubulin Destabilizers for the Treatment of Glioblastoma.

Glioblastoma (GB) is the most lethal brain cancer in adults, with a 5-year survival rate of 5%. The standard of care for GB includes maximally safe surgical resection, radiation, and temozolomide (TMZ) therapy, but tumor recurrence is inevitable in most GB patients. Here, we describe the development of a blood-brain barrier (BBB)-penetrant tubulin destabilizer, RGN3067, for the treatment of GB.

Efficient discovery of inhibitory ligands for diverse targets from a small combinatorial chemical library of chimeric molecules.

Living systems are mainly composed and regulated by compounds in four biochemical classes and their polymers-nucleotides, carbohydrates, lipids, and amino acids. Early combinatorial chemistry libraries consisted of peptides. The present report describes the general bioactivity and biophysical properties of a combinatorial chemical library that used glyco, nucleotidyl, and lipid building blocks.

Combinatorial chemistry reveals a new motif that binds the platelet fibrinogen receptor, gpIIbIIIa.

Among cell adhesion molecules, the classic Arg-Gly-Asp (RGD) motif is the best studied. We used combinatorial chemical and affinity immunochemical methods to find a novel motif of unnatural peptide ligands for the fibrinogen receptor of platelets, gpIIbIIIa (alphaIIbbeta3). The new d-amino acid motif, p(f/y)l, is unique among the ligands that bind the RGD pocket: It lacks the carboxylic acid group that is believed to coordinate with calcium in the MIDAS motif of the receptor.

Development of CD4 and CD8 single positive T cells in human thymus organ culture: IL-7 promotes human T cell production by supporting immature T cells.

This paper describes novel model systems to study the development of human T cells. Fragments of neonatal human thymus (HUNT) can be cultured in vitro; the initial majority population of CD4, CD8 double-positive (DP) thymocytes is not maintained in organ culture. These cells are rapidly replaced by populations of CD4 or CD8 single-positive (SP) T cells.

T cell tolerance and activation to a transgene-encoded tumor antigen.

Much has been learned in recent years concerning the nature of tumor antigens recognized by T cells. To apply this knowledge clinically, the nature of the host response to individual and multiple tumor antigens has to be characterized. This will help to define the efficacy of immune surveillance and the immune status of the host following exposure to tumor antigens expressed on pre-neoplastic tissue.

One bead, one chemical compound: use of the selectide process for anticancer drug discovery.

A technology for chemical synthesis and testing of libraries of millions of chemical entities has been developed for rapid molecular and cellular screening for drug leads. Each individual compound in the library is on a separate resin bead. Screening for binding activity can be conducted directly on the beads.

Human bone marrow and umbilical cord blood cells generate CD4+ and CD8+ single-positive T cells in murine fetal thymus organ culture.

Murine fetal thymus lobes isolated from both normal and scid/scid mice can be colonized by donor cells from either human bone marrow or human umbilical cord blood in vitro. Subsequent organ culture results in a transient production of a few CD4+ CD8+ (double-positive) cells and then the accumulation of CD4+ or CD8+ (single-positive) T cells. A significant number of immature T-cell intermediates (e.

Tolerance and MHC restriction in transgenic mice expressing a MHC class I gene in erythroid cells.

Transgenic mice carrying a MHC class I structural gene (H-2Kb) linked to transcriptional control elements from the human beta-globin gene, which direct erythroid lineage specific transcription, express H-2Kb molecules in red blood cells but H-2Kb expression cannot be detected in skin or lymphoid cells. This limited pattern of self MHC expression is sufficient to induce tolerance to H-2Kb molecules and H-2Kb restricted cytotoxic T cell responses can be generated in transgenic mice. Transgenic mice are unable to mount H-2Kb specific cytotoxic T cell responses in vitro, even when exogenous IL-2 is provided.

Rejection of MHC incompatible, Langerhans cell-free epidermal keratinocyte allografts in the rat.

Cultured murine epidermal keratinocyte allografts, depleted of MHC class II positive Langerhans cells, are not rejected by normal adult mice. This study investigates the survival of rat keratinocyte allografts depleted of MHC class II positive cells. Our results show that rat keratinocyte allografts are rejected rapidly in the absence of donor-derived, Langerhans cells.

The influence of MHC-compatible and MHC-incompatible antigen-presenting cells on the survival of MHC-compatible cultured murine keratinocyte allografts.

Our group has shown previously that APC-depleted cultured epidermal keratinocytes show prolonged survival when grafted onto normal MHC-incompatible adult mice. We show here that in vitro culture also improves significantly the survival of MHC-compatible keratinocyte allografts, although these nonrejected grafts are repopulated by host cells identified by their dendritic morphology and phenotype (class II+, leukocyte-common antigen+) as APCs. Reconstitution of cultured grafts, immediately prior to transplantation, with MHC-compatible dendritic cells of either donor or recipient origin, results in graft rejection--thus demonstrating that cultured cells can be rejected by the recipient animal--and suggests that a paucity of APCs in the immediate postgrafting period is responsible for the privilege afforded these grafts.

Cultured keratinocyte grafts are recognized, but not rejected by CD8+ T cells in vivo.

It has been shown in the mouse that cultured keratinocyte allografts [fully major histocompatibility complex (MHC) mismatched] survive for at least 100 days without evidence of rejection. In an attempt to analyze the immune mechanisms underlying this phenomenon we have investigated the induction of tolerance to such grafts. Primary cultures of BALB/c keratinocytes were prepared using irradiated 3T3 feeder cells, and the cultured cell sheets were grafted, using a silicone transplantation chamber, onto CBA recipients.

MHC class II antigen expression is not induced on murine epidermal keratinocytes by interferon-gamma alone or in combination with tumour necrosis factor-alpha.

Epidermal keratinocytes are induced to express MHC class II molecules in a variety of disease states associated with immune activity. To investigate the mechanism of this process we have exposed murine and rat keratinocytes to a variety of lymphokines and monitored changes in their MHC molecule expression. Murine cultured keratinocytes were treated with recombinant interferon-gamma (IFN-gamma), and MHC antigen expression quantified by flow cytometry.

The effect of interferon-gamma treatment of rat tumour cells on their susceptibility to natural killer cell, macrophage and cytotoxic T-cell killing.

The effect of exposing tumour cells to interferon-gamma (IFN-gamma) has been studied investigating changes in MHC antigen expression and susceptibility to a variety of cellular effector mechanisms. Treatment of rat tumour cell lines with rat recombinant IFN-gamma increased their expression of class I MHC molecules, as monitored by quantitative immunofluorescence. Reduced sensitivity to lysis by NK cells was observed, although cold-target competition assays indicated NK cells were bound equally well by both interferon-treated and control cells.

Class and subclass anti-pneumococcal antibody responses in splenectomized patients.

Antibody titres against pneumococcal capsular and cell wall antigens and the immune response to polyvalent pneumococcal vaccine were measured in 21 splenectomized patients and 12 healthy controls. Most individuals possessed anti-pneumococcal capsular polysaccharide antibodies of IgG, IgA and IgM classes. The anti-capsular IgG was predominantly of the IgG1 and IgG2 subclasses; only occasional individuals had any detectable titre in IgG3 or IgG4 subclass.