V. Silobrcic

Radiation therapy and Corynebacterium parvum in the treatment of murine tumors.

The relative effectiveness of local irradiation alone or combined with Corynebacterium parvum (C parvum) treatment has been investigated employing four tumors: a mammary carcinoma (MCa) (nonimmunogenic), a fibrosarcoma (moderately strongly immunogenic), and two squamous cell carcinomas (SCC‐2 being weakly and SCC‐4 being very weakly or nonimmunogenic). C parvum treatment was started when the isotransplanted tumor growing in the mouse leg was 5 mm in diameter and the local irradiation was administered to 8‐mm diameter tumor. Effect of the combined treatment was barely evident with the MCa but strongly present in FSa; up to 60% of mice were cured of FSa by C parvum alone and the response to low radiation doses, e.g., 200 rads, was highly increased. For SCC‐2 the TCD50 was ≈ 7000 rads and 3000 rads in control and test mice, respectively. Comparable values for SCC‐4 were 7700 and ≈ 5500 rads. Importantly, for SCC‐4 there was a large and highly significant reduction in the proportion of mice that died of metastases to lung but were free of evident tumor at the primary site.

Chimaerism in lymph nodes of F1 into irradiated parental recipient chimaeras rejecting skin allografts from the other parent.

SUMMARY Mice of the C57BL strain were irradiated with 800 R over the whole body. The next day they received i.v. a mixture of 50 × 106 spleen and bone marrow cells from (C57BL × CBA-T6T6)F1 hybrid mice, and were challenged with CBA-T6T6 skin grafts later on. About 20% of the recipients rejected the CBA-T6T6 skin, whereas the others were completely tolerant for more than 200 days. By using the cytotoxic test, we found that both tolerant and nontolerant recipients were complete chimaeras, i.e., had only (C57BL × CBA-T6T6)F1 cells in their lymph nodes. However, analysis of the same mice by the chromosome marker technique disclosed a proportion of host (C57BL) cells in lymph nodes of both tolerant and nontolerant chimaeras. The percentage of host metaphases in nontolerant chimaeras was significantly higher than that in tolerant chimaeras (P < 0.01). It is possible therefore that the CBA-T6T6 skin grafts were rejected by residual host (C57BL) cells rather than (C57BL × CBA-T6T6)F1 cells reacting against skin-specific transplantation antigen (s) of the parental graft.

Defective phagocytosis in chronic trichophytosis

Chronic trichophytosis as a primary clinical entity (primary chronic trichophytosis, PCT) is increasingly encountered in the literature. Its prevalent cause in Croatia is the anthropophilic form of Trichophyton interdigitale. Chronicity of the disease may result from immunological defects of the patients. Thus, in 62 patients with PCT: skin testing, enumeration of T- and B-lymphocytes in the peripheral blood, quantitation of immunoglobulin classes, and phagocytosis (random mobility, ingestion, digestion and extracellular killing) by peripheral blood leukocytes was tested. The findings were compared to those in healthy persons. Defective phagocytosis (random mobility, ingestion and digestion) was found in patients with PCT (P < 0.001). All the other results were within the control range. Therefore, PCT seems to be associated with defective phagocytosis of peripheral blood leukocytes in affected persons.

Quantitative Transplantation Assays of the Rat Rhabdomyosarcoma Ba1112 Isografts Into the Wag Rij-Y Rat and Xenotransplantation Into the Athymic Ncr(Nu-Nu) Nude-Mouse

Quantitative tumor cell transplantation assays have been performed to compare the transplantability of rat rhabdomyosarcoma BA1112 into isologous WAG/Rij Y rats and athymic NCr(nu/nu) nude mice. The end-point was the TD50 or the number of viable tumor cells which would transplant the tumors into half of the recipients. At Yale, two sets of 2-fold dilutions were prepared, one was sent to the MGH by Air Express. That afternoon, concurrent assays were performed at Yale using the WAG/Rij Y rat and at MGH using the NCr(nu/nu) mouse. The TD50 values were the same for iso- and xenotransplantation. Furthermore, the TD50s in rats and mice were unaffected by standard immunization procedures prior to challenge of the TD50 assay. The BA1112 (10(7) trypan blue excluding cells) grew to 10-12 mm and then completely regressed if transplanted into NCr(nu/+) mice which had received 6 Gy whole body irradiation but did not grow in control NCr(nu/+) mice. The times for the BA1112 to grow to 10 mm were the same in normal or preimmunized WAG/Rij Y rats or NCr(nu/nu) mice and in 6 Gy WBI NCr(nu/nu) mice. All of the experimental data show that the xenogenic NCr(nu/nu) mice accept the BA1112 as readily as do the isologous WAG/Rij Y rats.

In vitro inhibition of macrophage spreading by antigens and lymphokines: correlation with the footpad test and kinetics of inhibition.

As inhibition of spreading of mouse peritoneal macrophages is the basis for an in vitro test of cellular immunity, this test was used to investigate the correlation between in vitro and in vivo results and the kinetics of inhibition of spreading. BALB/c and NIH strain mice were immunized with human or bovine serum albumin or bovine gamma globulin. They displayed a positive footpad test when challenged with the specific antigen (21 days later). Peritoneal cells (PC) of mice with a strong footpad reaction were used for the spreading inhibition test. Intensity of spreading inhibition correlated well (r = -0.93) with that of the footpad reaction. Spreading inhibition had a cyclic pattern. A similar pattern was observed after incubation of PC with preformed lymphokines. The cyclic pattern was probably caused by a repeated action of lymphokines on spread macrophages, resulting in reversible and re-inducible inhibition.

Immune reaction of tumor-bearing mice to Propionibacterium acnes and the antitumor effect of the bacteria.

SummaryThe relationship between immunological reaction to Propionibacterium acnes (PA) and the antitumor effect of the injected bacterium was investigated. The aim was to determine whether the strength of the immune reaction to the bacterium can be used to predict its antitumor effectiveness. C3Hf/Sed mice received SC injections (right thigh) of viable cells of a methylcholanthrene-induced fibrosarcoma. When the tumor grew to 5 mm, the hosts received 350 μg PA IV as the antitumor treatment. Cellular immunity (footpad test) to PA was assayed in one group of these mice 14 days later, and in the other anti-PA agglutinins were determined 28 days later. The PA injection cured 22 of 58 mice in the first, and 20 of 46 mice in the second group. Footpad reaction and agglutinin titers to PA in cured mice were not statistically different from those in mice eventually killed by the tumor. Therefore, the strength of the immune reaction to PA in tumor-bearing mice could not be used to predict the antitumor effectiveness of the bacterium.

Specific cellular immunity detected by the in vitro monocyte spreading inhibition test in patients with bronchogenic carcinoma

SummaryThe test of the in vitro inhibition of monocyte spreading detected specific cell-mediated immunity (CMI) to melanoma-associated antigens in patients with melanoma. In this study we investigated the applicability of the test for assessment of specific antitumour immunity in patients with bronchogenic squamous-cell carcinoma (BSCa). Mononuclear blood cells of patients with the tumour were exposed to a soluble antigenic preparation, obtained by high-speed centrifugation of a homogenate of freshly excised BSCa tissue. The preparation inhibited the spreading of allogeneic monocytes from a group of 26 patients with BSCa (P=0.0023), but it did not inhibit monocytes from healthy laboratory personnel or those of patients with bronchogenic oat-cell carcinoma, benign lung tumours, or chronic tuberculosis. However, the same BSCa preparation inhibited (0.05>P>0.025) the spreading of monocytes from healthy hospital personnel (who were in prolonged contact with patients). At the same time, the monocytes of patients with BSCa were not inhibited by similarly obtained preparations from a normal lung, a benign thymoma, and a uterine squamous-cell carcinoma. We concluded that the in vitro test of monocyte spreading inhibition can detect specific CMI to antigens associated with the allogeneic BSCa in patients with the tumour.

Primary Immune Reaction of Allogeneic Lymph Node Cells against Tissue Antigens of Lethally Irradiated Hosts

The precise mechanism of the disease that develops after successful grafting of immunologically competent cells into allogeneic hosts (“allogeneic disease”) is still obscure. We have studied it using as a model an “acute allogeneic disease” caused by a mixture of bone marrow and lymph node cells injected into lethally irradiated allogeneic mice. From serially killed animals we have obtained a number of very reproducible patterns of the disease (l).

The effect of allogeneic presensitization on Hya-isograft survival

The effect of allogeneic presensitization on Hya isograft survival was reinvestigated in C57BL, C3H and (C57BL x C3H)F1 females. Three weeks after transplantation of H-2 or non-H-2 differing female or male skin grafts, a syngeneic male skin graft (Hya isograft) was transplanted onto female recipients. C57BL and (C57BL x C3H)F1 females pretreated with a female skin graft of any origin rejected the C57BL male isograft as a first-set, while females pretreated with a male skin graft rejected the C57BL male isograft in a second-set manner. The same happened with the C3H male skin graft transplanted onto previously challenged (C57BL x C3H)F1 females. C3H females pretreated with a C3H or CBA female graft rejected the C3H male isograft as a first-set, whereas those pretreated with a C3H or CBA male graft rejected the male C3H isograft in a second-set manner. However, after pretreatment with a BALB/c male skin graft, C3H females were not sensitized to Hya. They rejected the C3H male isograft slightly faster than was expected for the first graft but this accelerated rejection was not specific, since it occurred as well in C3H females pretreated with grafts of BALB/c females. The best explanation for this unsuccessful immunization of C3H females is that an inferior, non-H-2-dependent Hya recognition system is involved in male isograft rejection.