HIV-1 Langerhans' Cell Tropism Associated with Heterosexual Transmission of HIV

Abstract

7 P De Togn e t a / , i b~d , p 703, T. A Banks et a1 , J /n?n?uno/ 155, 1685 (1 995) 8 Mce were ~mmun~zed intrapertoneally w~th 100 &I of phosphate-buffered sane contanng 10% SRBCs (22) Ten days later, spleens were harvested, embedded In 0 C.T compound (M~les), and frozen In q u d ntrogen Frozen t~ssue sections (6 to 10 &m th~ck) were f~xed n cold acetone Endogenous per-ox~dase was q~~enched w~th 0 2% H, O, n methanol Sectons were sta~ned by f~rst ncubatng w~t h PNA-b~o t~n (Vector) and w~th rat antserum produced to IgD (Southern B~otechnology) After wash~ng, the sections were further incubated w~th strepta\/id~n conj~lgated w~th alkalne phosphatase (AP) (Zymed) and rabb~t ant~body to rat IgG conjugated w~th horse-rad~sh perox~dase (HRP) (Southern B~otechnology) Color development for bound AP and HRP was w~th an AP reacton k~t (Vector) and w~t h d~arn~nobenz-d~ne Sect~ons were then countersta~ned w~th 1 % methyl green 9 M. L Rose, M S C B~rbeck, V J Wall~s, J A Forrester. A J Daves. Nature 284, 364 (1980) 10 T

Cell reservoirs in lymph nodes infected with HIV-1 subtype E differ from subtype B: identification by combined in situ polymerase chain reaction and immunohistochemistry

“…41 In addition, previous in vitro work has shown that the HIV virus has the ability to replicate in epithelial Langerhans cells, and that subtype E replicates more readily than does subtype B, 7,42 although not all studies have confirmed this. 43,44 Since epithelial Langerhans cell may be the first to encounter the virus after mucosal transmission, 45 the ability of the virus to grow in these cells might enhance viral transmission and could help explain the epidemiologic findings of increased heterosexual transmission in Thailand and Southeast Asia.…”

“…While HIV-1 subtype E accounts for B10% of cases worldwide, in Thailand more than 90% of sexually transmitted HIV-1 cases are subtype E 2-4 and heterosexual transmission is the major mode of spread via a mucosal route. [5][6][7] It has been calculated that heterosexual transmission occurs five times more frequently per heterosexual exposure in Thailand compared to the US. 8 It has therefore been suggested that there is an increased propensity for transmission of subtype E as opposed to subtype B during heterosexual exposure.…”

“…7 As these cells may be among the first to encounter the virus after mucosal transmission, an increased ability of the virus to grow in Langerhans cells might enhance virus transmission and could contribute to the epidemiologic findings of increased heterosexual transmission in Southeast Asia. In a previous study, we showed that Langerhans cells and related dendritic cells located in vaginal mucosa of HIV-infected patients were infected with subtype E. 9 We postulated that the increased propensity for heterosexual transmission of subtype E might be related to vaginal inflammation, leading to the accumulation of Langerhans cells and related dendritic cells, which, once infected with HIV, could then act as a reservoir for further viral transmission.…”

In Vivo Identification of Langerhans and Related Dendritic Cells Infected with HIV-1 Subtype E in Vaginal Mucosa of Asymptomatic Patients

“…The HIV virus has been demonstrated in vitro to have the ability to replicate in epithelial Langerhans cells (LCs), and there is evidence to suggest that Subtype E more readily replicates than Subtype B (7,8). Because these cells may be the first to encounter the virus after mucosal transmission, the ability of the virus to grow in LCs might enhance viral transmission and may explain the epidemiologic findings of increased heterosexual transmission in Thailand and Southeast Asia (8).…”

“…Because these cells may be the first to encounter the virus after mucosal transmission, the ability of the virus to grow in LCs might enhance viral transmission and may explain the epidemiologic findings of increased heterosexual transmission in Thailand and Southeast Asia (8). Using the SIV/macaque system, Spira et al (9) reported that the first host cells to be infected were cells of dendritic morphology located in the lamina propria of the vaginal mucosa.…”