Breast cancer skin test antigens of increased sensitivity prepared from vesicular stomatitis virus-infected tumor cells

T cell responses to ovarian tumor vaccines: identification and significance for future immunotherapy

The cellular immune responses to ovarian cancer patients treated with viral oncolysates (VO) ovarian tumor vaccines to vaccines are described. CD3+ cells proliferated after stimulation with the tumor vaccines in a dose-dependent manner. The proliferation of CD3+ cells stimulated with the tumor vaccine was blocked by anti-HLA-DR monoclonal antibody and anti-CD4 mAb indicating that CD3+ CD4+ cells from the blood of the patients treated with VO recognize tumor derived determinants in conjunction with MHC class II antigens. The regulatory activity of the T cells collected after VO treatment was assayed by co-cultivation with PBMC collected before VO treatment. These cells demonstrated increased helper activity for immunoglobin production by cells collected before vaccination and secreted IL-2 in response to stimulation by vaccine. Finally, when biochemical fractionation of the components of VO was attempted, PBMC from VO treated patients responded by proliferation to several fractions suggesting that they recognize multiple epitopes in the ovarian tumor vaccine. Therefore, these data provide novel evidence for the involvement of the T cells in response to ovarian tumor vaccines.

Malignant melanoma. Inflammatory mononuclear cell infiltrates in cerebral metastases during concurrent therapy with viral oncolysate

Five patients with advanced malignant melanoma, treated with viral oncolysate, had solitary central nervous system metastases that were removed surgically. Histologic examination revealed striking and significant mononuclear inflammatory cell infiltrates, consisting of a mean of 60% plasma cells and a lesser proportion of lymphocytes at the edges of the lesions, within their supporting fibrovascular trabeculae, and among the tumor cells. Comparable inflammatory changes were not found in solitary metastatic malignant melanomas removed surgically from the brains of 19 patients not treated with viral oncolysate. Similarly, multiple metastatic malignant melanomas obtained postmortem from the brains of 12 patients not treated with viral oncolysate showed minimal inflammatory responses. Ultrastructural examination of material from a single treated patient revealed morphologic abnormalities of the blood-brain barrier, changes that were perhaps conducive to infiltration of the neoplasm by inflammatory cells. The authors suggest that administration of viral oncolysate enhances the inflammatory cell response to metastatic malignant melanoma in the brain.

Immune recognition of tumor cells in mice infected with Pichinde virus

Pichinde virus (PV), a member of the Arenaviridae family, protects mice from a lethal inoculation with the sarcoma 180 (S180) tumor cell line. Virus replication, which is required for protection, occurs primarily in the spleen and tumor. During the first 4 days, elevated natural killer (NK) cell activity parallels an increase in serum interferon in PV-infected mice. On day 7 after infection virus-specific cytotoxic T cells (CTLs) are found in the mouse. This strong response peaks on day 13 and gradually declines over the next 17 days. The tumor-specific CTL response appears more slowly and is less intense than the virus-specific response, especially in the uninfected mouse. However, CTLs from either type of mouse recognize PV-infected tissue culture S180 target cells better than uninfected ones. Even though the primary tumor-specific immune response appears weak, mice that have cleared both virus and tumor are refractory to a subsequent challenge with S180 cells and rapidly produce tumor-specific CTLs. Thus, our data indicate a number of ways in which virus infection could lead to immune elimination of tumors: (1) Virus-induced interferon stimulates NK-cell activity, which in turn could control tumor load until a specific response is mounted against the S180 cells; (2) early onset of the tumor-specific T-cell response could be brought about by viral-enhanced tumor antigen presentation to the immune system; and (3) the tumor-specific T-cell response could be augmented through a "bystander' phenomenon involving factors associated with T cells responding specifically and vigorously to the virus itself.

Virus-augmented delayed hypersensitivity skin tests in gynecological malignancies

Cultured human tumor cells of various histologic origins were infected with PR8/A/34 influenza virus. Nonviable crude membrane extracts were derived from the infected and uninfected cells. The extracts were coded and tested for their ability to produce delayed hypersensitivity skin reactions (DHSR) in allogeneic patients with squamous uterine cervical carcinoma, epithelial ovarian carcinoma, and malignant melanoma. Augmented antigen sensitivity to the virus-modified extracts compared with virus alone or to the unmodified extracts was observed in all patient groups. There was insufficient specificity to delineate a response by individual tumor type and related tumor extract, but some of the observed responses suggested tumor or organ site associations. Cervical carcinoma patients reacted more frequently to the virus-modified cervix extract, which also produced a high frequency of response in patients with ovarian carcinoma and melanoma. Ovarian carcinoma patients demonstrated increased sensitivity to both virus-modified ovarian carcinoma extracts, although 14 of 21 patients also showed responsiveness to one of the unmodified ovarian extracts. Malignant melanoma patients showed increased sensitivity to all virus-modified extracts except one of two derived from the ovarian carcinoma, and demonstrated a significantly augmented response to the virus-modified melanoma extract when the response to this extract was compared with that in ovarian carcinoma patients. The augmented reactions appear to be due to an association of the PR8 virus and as yet undetermined cellular components rather than to the virus alone. The possible involvement of tumor-associated determinants and the clinical significance of this phenomenon require further investigation.