DEPRESSION BY ANTIBODY OF THE IMMUNE RESPONSE TO HOMOGRAFTS AND ITS ROLE IN IMMUNOLOGICAL ENHANCEMENT

This paper reports tests of two hypotheses that have been proposed to account for the enhanced growth of tumor homografts in the presence of antiserum reactive with the graft (immunological enhancement). According to the first hypothesis, enhancement is due to some "physiological" alteration in the tumor, induced by its contact with antiserum, which insures its survival despite the hostile response of the host. According to the second hypothesis, antiserum alters the response of the host. By blocking the development of the cellular type of immunity, which is the main agent in graft destruction, it permits the graft to survive. To test hypothesis 1, strain A tumor SaI was passed from A's, and from enhanced B10.D2's, into untreated B10.D2's. The per cent of deaths was essentially the same in both groups (48 and 44 per cent, respectively); there was no evidence that passage through enhanced B10.D2's altered the capacity of the tumor to grow in the foreign strain. Several other groups of mice included in the experiment all confirmed this conclusion. The experiment failed to confirm hypothesis 1. In the tests of hypothesis 2, the effect of isoantiserum on immune responses of both the humoral and cellular type was measured. When antiserum was given together with foreign strain lymphoid cells (antigen), almost no additional antibody was manufactured; in contrast with this, controls receiving foreign cells only produced red cell agglutinating antibody in high titer. The effect of antiserum on the development of immunity of the cellular type was tested by the method of Winn. In this assay, presumptively immune node cells, in various dilutions, are mixed with tumor cells and injected into appropriate mice. Immunity is indicated by inhibited tumor growth. Antiserum given at the same time as a tumor homograft greatly depressed the immunity of the cells expressed from the draining nodes. At 6 days after the graft, the level of immunity of cells from treated mice was 1/24th to 1/32nd that of cells from controls receiving tumor alone. The same sort of depressing effect was noted when the immunizing tissue was foreign thymus or embryo. Antiserum given 1 or more days after the immunizing tissue also resulted in a lower level of cellular immunity (but the assay used in this case was a less critical one). These results provide an adequate explanation of the phenomenon of immunological enhancement, at least as it occurs in the particular test system used in these experiments. Since it is cellular immunity rather than humoral antibody that inhibits the growth of most grafts (transplantable leukemias are an exception), the depression of this immunity by antibody is favorable to the growth of a homograft

Bridging the Gap: FPGAs as Programmable Switches

The emergence of P4, a domain specific language, coupled to PISA, a domain specific architecture, is revolutionizing the networking field. P4 allows to describe how packets are processed by a programmable data plane, spanning ASICs and CPUs, implementing PISA. Because the processing flexibility can be limited on ASICs, while the CPUs performance for networking tasks lag behind, recent works have proposed to implement PISA on FPGAs. However, little effort has been dedicated to analyze whether FPGAs are good candidates to implement PISA. In this work, we take a step back and evaluate the micro-architecture efficiency of various PISA blocks. We demonstrate, supported by a theoretical and experimental analysis, that the performance of a few PISA blocks is severely limited by the current FPGA architectures. Specifically, we show that match tables and programmable packet schedulers represent the main performance bottlenecks for FPGA-based programmable switches. Thus, we explore two avenues to alleviate these shortcomings. First, we identify network applications well tailored to current FPGAs. Second, to support a wider range of networking applications, we propose modifications to the FPGA architectures which can also be of interest out of the networking field.Comment: To be published in : IEEE International Conference on High Performance Switching and Routing 202

A sex-limited serum protein variant in the mouse: Inheritance and association with the H-2 region

An alloantiserum produced in the mouse has been used to detect an antigen which is present only in male serum from certain inbred strains of mice, e.g., DBA/2J, A/J, and BALB/c. Genetic tests reveal that the presence of this antigen is controlled by a dominant autosomal gene which is expressed only in males of the proper genotype. Test crosses and analysis of congenic resistant strains indicate close linkage between the sex-limited protein ( Slp ) and the histocompatibility-2 ( H-2 ) region of linkage group IX. Analysis of seven intra- H-2 recombinant strains is consistent with the placement of the genetic determinant for Slp within the H-2 region in the same position as the Ss (serum substance) determinant. Immunological evidence suggests that the Slp antigenic sites reflect structural variation in the Ss component of mouse serum.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44166/1/10528_2004_Article_BF00485752.pd

A new alloantigen, Ly-8, recognized by C3H anti-AKR serum

A new membrane alloantigen, designated Ly-8.2, is defined by a C3H anti-AKR serum. The locus, Ly-8 , which controls this determinant is not linked to Thy-1, Ly-4, Ly-6, H-2 , albino (c), or brown ( b ). Ly-8.2 has a unique strain distribution, and appears to be present on both T and B lymphocytes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46747/1/251_2005_Article_BF01576977.pd

Immunogenetic control of the response of female mice to male tissue grafts

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46736/1/251_2005_Article_BF01561664.pd

Evidence for a third, Ir -associated histocompatibility region in the H-2 complex of the mouse

Skin grafts transplanted from B10.HTT donors onto (A.TL × B10)F 1 recipients are rapidly rejected despite the fact that the B10.HTT and A.TL strains should be carrying the same H-2 chromosomes and that both the donor and the recipient contain the B10 genome. The rejection is accompanied by a production of cytotoxic antibodies against antigens controlled by the Ir region of the H-2 complex. These unexpected findings are interpreted as evidence for a third histocompatibility locus in the H-2 complex, H-2I , located in the Ir region close to H-2K . The B10.HTT and A.TL strains are postulated to differ at this hypothetical locus, and the difference between the two strains is explained as resulting from a crossing over between the H-2 t1 and H-2 s chromosomes in the early history of the B10.HTT strain. The H-2 genotypes of the B10.HTT and A.TL strains are assumed to be H-2K s Ir s / k Ss k H-2D d and H-2K s Ir k Ss k H-2D d , respectively. Thus, the H-2 chromosomes of the two strains differ only in a portion of the Ir region, including the H-2I locus. The B10.HTT( H-2 tt ) and B10.S(7R)( H-2 th ) strains differ in a relatively minor histocompatibility locus, possibly residing in the Tla region outside of the H-2 complex.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46727/1/251_2005_Article_BF01564045.pd