AN EVALUATION OF THE NORMAL LYMPHOCYTE TRANSFER TEST IN MAN

Biphasic response of the regional lymphatics in the normal lymphocyte transfer reaction

BACKGROUND

Initially developed for histocompatibility testing, the normal lymphocyte transfer (NLT) reaction involves the intradermal injection of allogeneic lymphocytes from one individual to another. Because of the unique kinetics of the immunological response to allogeneic lymphocytes, the NLT reaction has been considered an informative system for the analysis of transplant immunity.

METHODS

In this study, we used bilateral efferent lymph duct cannulations in sheep to examine the regional lymphatic response to the NLT reaction. Our studies used monoclonal antibodies to define lymphocyte population dynamics and DNA flow cytometry to reflect lymphocyte proliferative responses.

RESULTS

The results confirmed a biphasic NLT reaction. An unexpected finding was the marked differences between the early and late NLT responses. The early response was characterized by T-lymphocyte proliferation, as reflected by S-phase DNA, which was comparable in both the NLT-stimulated and contralateral control efferent lymphocytes. This bilateral proliferative response was observed in both CD4+ and CD8+ lymphocytes. In contrast, the late response was restricted to the efferent lymph from the NLT-stimulated lymph node. Dual-parameter flow cytometry demonstrated that the dominant component of this unilateral NLT response was CD8+ lymphocytes.

CONCLUSIONS

These results suggest important functional distinctions between systemic and regional lymphatic responses to intradermal alloantigens.

Normal lymphocyte transfer reaction in humans and its possible mechanism

This study illustrates the development of the skin reaction in human recipients to injected allogeneic lymphocytes from two aspects: the capacity of lymphocytes to elicit the reaction, and the ability of the recipient to react. The reaction is expressed by local skin induration and is biphasic. The first phase seems to be a hostgraft reaction; the second may require proliferation of graft cells as well as the reaction of host cells. Circulating fetal lymphocytes collected from a 12-week human embryo caused no reaction in an adult recipient; those from a 15-week embryo usually caused the first phase, with little or no second phase reaction, while those from 22- and 30-week fetuses and from a mature infant caused a normal, biphasic reaction. So, usually, did 22-week splenic lymphocytes, but fetal thymic lymphocytes usually provoked no reaction in adults. In premature infants given adult cells either both phases or the second were reduced; in normal infants the second response may be reduced but after six years of age the reaction is like that seen in adults.

BCG-induced protection against malignant melanoma: possible immunospecific effect in a murine system

This report documents for the first time BCG-induced protection against a murine malignant melanoma. Adult Balb/C mice recieved 0.1-cm3 doses of BCG prior to intramuscular challenge with 1 x 10-6 S-91 melanoma cells. A 65% reduction in melanoma incidence was noted in BCG-pretreated mice. The possibility of specific protection induced by the BCG against the melanoma exists, since the BCG pretreatment did not protect against challenge with 1 x 10-5 mammary carcinoma cells or 1 x 10-4 MCA fibrosarcoma cells in the same strain of mice. Lack of immunogenicity was not a factor in the inability of the carcinoma and sarcoma to be inhibited by BCG. The strenght of the BCG-induced protection against the S-91 melanoma was demonstrated by significantly decreased tumor incidence following three different log challenge doses of the melanoma. However, reduction of the sarcoma challenge dose to as few as 10-2 cells administered to BCG pretreated mice did not result in decreased tumor incidence. It was further discovered that as few as two doses of 0.1 cm3 of BCG were sufficient to produce a 70% reduction in melanoma incidence compared with the incidence in control animals (P less than .001). Lymphocyte-mediated cytotoxicity studies paralleled the results of the in vivo experiments. Lymphocytes immune to each of the three tumors showed significant cytotoxicity against their respective tumor target cells (p less than .001), while the only tumor cells that lymphocytes from BCG-pretreated mice showed significant cytotoxicity against were S-91 target cells (p less than .01). Nonspecific cytotoxicity was not a factor in the effect of BCG-immune lymphocytes against S-91 target cells, since BCG-immune lymphocytes were not cytotoxic to Balb/C fibroblasts.

Induction of immunological tolerance to allogeneic tissues in the canine species

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Normal lymphocyte transfer tests in leprosy

Lymphocyte transfer tests (intradermal inoculations of 2·5 million of allogenic lymphocytes) were done in five normal persons, five lepromatous leprosy and four tuberculoid leprosy patients. Observations were made daily for at least 10 days. In normal persons an initial reaction of moderate induration and erythema reached its maximum diameter between 24 and 48 hr and a secondary reaction occurred on the 3rd–5th day, reached its peak on the 6th–7th day and disappeared between the 10th and 13th day. In the lepromatous leprosy cases there was neither an initial nor a secondary reaction. In two of four cases of tuberculoid leprosy only an initial reaction was observed while in the other two cases the reaction appeared on the 4th day, reached its peak on the 6th day and persisted to the 13th day.

The application of the normal lymphocyte transfer reaction to histocompatibility testing in man

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