Jerry L. Hudson

Lymphocyte subpopulations infiltrating squamous carcinomas of the head and neck: Correlations with extent of tumor and prognosis

Because little is known about the mechanisms involved in local tumor-host immune reactions in squamous carcinoma of the head and neck, a study was undertaken to better characterize the types of immune cells present at the local tumor site and determine their relationship to tumor extent, systemic cellular immune parameters, and clinical outcome. In 40 untreated patients, lymphocyte subsets (LS) at the tumor-host interface were quantitated immunohistologically from serial sections of frozen tumor specimens and correlated with concurrently measured peripheral LS levels and in vitro lymphocyte reactivity to phytohemagglutinin (PHA). The majority of infiltrating lymphocytes were T cells with rare B or Leu 7 cells. Proportions of T4 and T8 were similar in peritumor stroma; however, T8 cells predominated tumor parenchyma. Stromal and parenchymal infiltration by LS were not related to peripheral blood LS levels, lymphocyte reactivity, or tumor site. However, parenchymal T11 and T4 cell infiltration was less in advanced primary tumors (T3, T4) than in early tumors (T1, T2) (P = 0.01, P = 0.067, respectively), as was peripheral lymphocyte reactivity to PHA (P = 0.013). Short-term disease-free interval and actuarial survival differed significantly—according to parenchymal T11 and T4 cell infiltration—and were not related to T8, leu 7, and B-cell infiltration. The findings extend prior studies of lymphocytic infiltration in head and neck cancer and demonstrate the potential importance of differences in tumor stromal and parenchymal infiltration. Together with recent evidence that T4 cells are critical for lymphokine production and for the proliferation of cytotoxic effector cells, the current results suggest that T4 cells play a critical role in the local immune response in squamous carcinoma of the head and neck.

CD4+ cells treated with DNA methylation inhibitors induce autologous B cell differentiation

The DNA methylation inhibitor 5-azacytidine induces autoreactivity in cloned CD4+ T cells, but the functional consequences of this response are unknown. We now report that CD4+ T cells treated with 5-azacytidine respond to autologous antigen-presenting cells and induce autologous B cell differentiation without exogenous antigen or mitogen. This mechanism could play a role in some autoimmune diseases characterized by T cell DNA hypomethylation and polyclonal B cell activation.

Increased immunoglobulin response to γ-interferon by lymphocytes from patients with systemic lupus erythematosus

The factors responsible for abnormal B-cell activation in systemic lupus erythematosus (SLE) are incompletely understood. This study tested the hypothesis that the abnormal B-cell activation observed in human SLE may be due to an augmented response to a helper signal. We demonstrated that non-T cells from 10 of 19 SLE patients increased IgG production in response to interferon-gamma (IFN-gamma) by a mean factor of 20.9 +/- 3.9 over resting levels, while controls stimulated a mean factor of 3.0 +/- 0.5 (P less than 0.005). We found no relationship of IFN-gamma responsiveness to disease activity. Serotyping for HLA A, B, C, and D loci suggested that the hyperresponsiveness may be genetically linked to HLA-Cw7. We conclude that IFN-gamma may contribute to the development and perpetuation of SLE in a subset of patients with SLE.

Triciribine (TCN), A Novel Tricyclic Adenosine Analog with Anticancer Activity

Abstract Triciribine shows promise as an antitumor drug and is currently in clinical trials. In L1210 cells in vitro, triciribine lethality is associated with inhibition of DNA synthesis, a G1(-S) cell progression block and slowing of progression of cells through s phase.

Activity of acyclic halogenated tubercidin analogs against human cytomegalovirus and in uninfected cells

Novel acyclic halogenated tubercidins (4-amino-5-halo-7-[(2-hydroxyethoxy)-methyl]pyrrolo[2,3-d]pyrimidines) were examined for their ability to inhibit human cytomegalovirus (HCMV) in yield reduction assays. 5-Bromo acyclic tubercidin (compound 102) was a more potent inhibitor of virus replication than the chloro- and iodo-substituted analogs (compounds 100 and 104). At a 100 microM concentration, the bromo and chloro compounds were more potent than acyclovir but not ganciclovir. Virus titers were reduced more than 99% by compounds 102 and 104 whereas compound 100 and the equally potent acyclovir reduced titers by only 90%. Quantitation of viral DNA by DNA hybridization demonstrated strong inhibition of HCMV DNA synthesis by these compounds. The most potent inhibitor, compound 102, had a 50% inhibitory (I50) concentration (1.6 microM) comparable to that of ganciclovir (1.8 microM). Cytotoxicity in uninfected human cells was evaluated and revealed the following: cell growth rates slowed markedly in the presence of 10 microM compound 102 whereas the same concentration of compounds 100 and 104 led to only a slight prolongation of population doubling time; these compounds inhibited cellular DNA synthesis but not RNA or protein synthesis, as measured by incorporation of radiolabeled precursors into acid-precipitable macromolecules; flow cytometry indicated that compound 102 was a mid-S phase blocker, and adenosine antagonized the inhibition of [3H]dThd incorporation by compound 102. Together, these results demonstrate that compound 102 is a potent and selective inhibitor of viral and cellular DNA synthesis and that acyclic halogenated pyrrolo-pyrimidine nucleosides may have therapeutic potential.