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Previously we reported that the combination of anti-PD1 and β-alethine completely stopped cancer growth in a syngeneic mouse melanoma model even under conditions when neither of the drugs had statistically significant effects as a single agent. In order to further examine this dramatic result, we extended the studies, evaluated immune parameters and tested if long-term immunity to re-challenge occurred. Surprisingly, three low doses of anti-PD1, spread over 9 days, were sufficient to allow concurrent and continuing weekly dosing of β-alethine to not only halt tumor growth, but to reverse it. The established melanoma regressed over the subsequent 4-6 weeks. Even more striking was that the short course of anti-PD1, which failed to reduce cancer growth as a single therapy, altered the immune system such that subsequent treatment with β-alethine was effective. β-alethine therapy, beginning eight days after the conclusion of anti-PD1 therapy, when tumors averaged 40 mm2, was sufficient to cause at least stabilization of cancer in all animals and complete response (no palpable tumor on repeated measurements) in the majority of animals. Statistical comparisons of all animals receiving combination therapy (either concurrently or sequentially) with controls resulted in significant differences using ANOVA for tumor size (p=0.005) or X2 tests for tumor presence (p Citation Format: Floyd E. Taub, Suzin Wright, Amanda Guth. Combination checkpoint inhibitor therapy: Anti-PD1 and Beta-alethine lead to complete responses of melanoma in a syngeneic mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-191. doi:10.1158/1538-7445.AM2017-LB-191

Peripheral blood lymphocytes from normal individuals and patients with autoimmune abnormalities such as insulin-dependent diabetes mellitus and thyroiditis were infected with Epstein-Barr virus, and the culture supernatants were tested for autoantibodies that reacted with normal tissues. Between 58 and 86% of Epstein-Barr virus-transformed cultures produced immunoglobulin M antibodies, and between 9 and 24% of the transformed cultures produced immunoglobulin G antibodies that reacted with normal tissues. Ten Epstein-Barr virus-transformed clones secreting human immunoglobulin M monoclonal autoantibodies were isolated. Four of these monoclonal autoantibodies were studied in depth and found to react with antigens in multiple organs, including thyroid, pancreas, stomach, smooth muscle, and nerves. It is concluded that Epstein-Barr virus can trigger the production of autoantibodies without infecting the target cells to which the autoantibodies are directed.

An increased prevalence of Type 1 (insulin-dependent) diabetes has been reported in patients with congenital rubella. Rubella virus multiplies in the pancreas, and we have hypothesized that studies of children with congenital rubella would be of great importance in following the development of Type 1 diabetes in a defined, susceptible population. Two hundred and forty-one children with congenital rubella (mean age 17.4 +/- 0.3 years; 65% black and hispanic) have been evaluated, 30 of whom already have diabetes and 17 of whom have borderline glucose tolerance. In these latter two groups, HLA-DR3 is significantly increased and HLA-DR2 significantly decreased. Pancreatic islet cell cytotoxic surface antibodies are found in 20% of the total congenital rubella population, including in more than 50% in the time period before they develop diabetes and are not related to any specific HLA type. In addition, anti-microsomal and anti-thyroglobulin antibodies are found in 34% of this population. The data demonstrate that Type 1 diabetes developing in congenital rubella patients has the genetic and immunological features of classical Type 1 diabetes, namely the presence of HLA-DR3, the absence of HLA-DR2, islet cell surface antibodies before decompensation and an increased prevalence of anti-thyroid antibodies. Patients with non-diabetic congenital rubella represent an easily identifiable group in whom other immunological factors associated with Type 1 diabetes can be elucidated and possibly modified.

Human monoclonal antibodies that react with normal tissues (autoantibodies) have recently been prepared from peripheral blood lymphocytes (PBLs) of patients with insulin-dependent diabetes mellitus (IDDM) and thyroiditis. This chapter describes the methods by which these monoclonal autoantibodies have been obtained and evaluates their reactivity with normal tissue antigens. In addition, the capacity of these monoclonal autoantibodies to react with antigens in multiple organs is described.